xref: /xnu-12377.61.12/bsd/kern/kern_exec.c (revision 4d495c6e23c53686cf65f45067f79024cf5dcee8)
1 /*
2  * Copyright (c) 2000-2020 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Mach Operating System
31  * Copyright (c) 1987 Carnegie-Mellon University
32  * All rights reserved.  The CMU software License Agreement specifies
33  * the terms and conditions for use and redistribution.
34  */
35 
36 /*-
37  * Copyright (c) 1982, 1986, 1991, 1993
38  *	The Regents of the University of California.  All rights reserved.
39  * (c) UNIX System Laboratories, Inc.
40  * All or some portions of this file are derived from material licensed
41  * to the University of California by American Telephone and Telegraph
42  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
43  * the permission of UNIX System Laboratories, Inc.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. All advertising materials mentioning features or use of this software
54  *    must display the following acknowledgement:
55  *	This product includes software developed by the University of
56  *	California, Berkeley and its contributors.
57  * 4. Neither the name of the University nor the names of its contributors
58  *    may be used to endorse or promote products derived from this software
59  *    without specific prior written permission.
60  *
61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71  * SUCH DAMAGE.
72  *
73  *	from: @(#)kern_exec.c	8.1 (Berkeley) 6/10/93
74  */
75 /*
76  * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
77  * support for mandatory and extensible security protections.  This notice
78  * is included in support of clause 2.2 (b) of the Apple Public License,
79  * Version 2.0.
80  */
81 #include <machine/reg.h>
82 #include <machine/cpu_capabilities.h>
83 
84 #include <sys/cdefs.h>
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/filedesc.h>
88 #include <sys/kernel.h>
89 #include <sys/proc_internal.h>
90 #include <sys/kauth.h>
91 #include <sys/user.h>
92 #include <sys/socketvar.h>
93 #include <sys/malloc.h>
94 #include <sys/namei.h>
95 #include <sys/mount_internal.h>
96 #include <sys/vnode_internal.h>
97 #include <sys/file_internal.h>
98 #include <sys/stat.h>
99 #include <sys/uio_internal.h>
100 #include <sys/acct.h>
101 #include <sys/exec.h>
102 #include <sys/kdebug.h>
103 #include <sys/signal.h>
104 #include <sys/aio_kern.h>
105 #include <sys/lockdown_mode.h>
106 #include <sys/sysproto.h>
107 #include <sys/sysctl.h>
108 #include <sys/persona.h>
109 #include <sys/reason.h>
110 #if SYSV_SHM
111 #include <sys/shm_internal.h>           /* shmexec() */
112 #endif
113 #include <sys/ubc_internal.h>           /* ubc_map() */
114 #include <sys/spawn.h>
115 #include <sys/spawn_internal.h>
116 #include <sys/process_policy.h>
117 #include <sys/codesign.h>
118 #include <sys/random.h>
119 #include <crypto/sha1.h>
120 
121 #include <libkern/libkern.h>
122 #include <libkern/amfi/amfi.h>
123 #include <libkern/crypto/sha2.h>
124 #include <security/audit/audit.h>
125 
126 #include <ipc/ipc_types.h>
127 
128 #include <mach/mach_param.h>
129 #include <mach/mach_types.h>
130 #include <mach/port.h>
131 #include <mach/task.h>
132 #include <mach/task_access.h>
133 #include <mach/thread_act.h>
134 #include <mach/vm_map.h>
135 #include <mach/mach_vm.h>
136 #include <mach/vm_param.h>
137 #include <mach_debug/mach_debug_types.h>
138 
139 #include <kern/sched_prim.h> /* thread_wakeup() */
140 #include <kern/affinity.h>
141 #include <kern/assert.h>
142 #include <kern/ipc_kobject.h>
143 #include <kern/task.h>
144 #include <kern/thread.h>
145 #include <kern/coalition.h>
146 #include <kern/policy_internal.h>
147 #include <kern/kalloc.h>
148 #include <kern/zalloc.h> /* zone_userspace_reboot_checks() */
149 
150 #include <os/log.h>
151 
152 #if CONFIG_MACF
153 #include <security/mac_framework.h>
154 #include <security/mac_mach_internal.h>
155 #endif
156 
157 #if CONFIG_AUDIT
158 #include <bsm/audit_kevents.h>
159 #endif
160 
161 #if CONFIG_ARCADE
162 #include <kern/arcade.h>
163 #endif
164 
165 #include <vm/vm_map_xnu.h>
166 #include <vm/vm_kern_xnu.h>
167 #include <vm/vm_protos.h>
168 #include <vm/vm_fault.h>
169 #include <vm/vm_pageout_xnu.h>
170 #include <vm/pmap.h>
171 #include <vm/vm_reclaim_xnu.h>
172 
173 #include <kdp/kdp_dyld.h>
174 
175 #include <machine/machine_routines.h>
176 #include <machine/pal_routines.h>
177 
178 #include <pexpert/pexpert.h>
179 #include <pexpert/device_tree.h>
180 
181 #if CONFIG_MEMORYSTATUS
182 #include <sys/kern_memorystatus.h>
183 #endif
184 
185 #include <IOKit/IOBSD.h>
186 #include <IOKit/IOKitKeys.h> /* kIODriverKitEntitlementKey */
187 
188 #include "kern_exec_internal.h"
189 
190 #include <CodeSignature/Entitlements.h>
191 
192 #include <mach/exclaves.h>
193 
194 #if HAS_MTE
195 #include <arm64/mte_xnu.h>
196 #endif /* HAS_MTE */
197 
198 extern boolean_t vm_darkwake_mode;
199 
200 /* enable crash reports on various exec failures */
201 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
202 
203 #if XNU_TARGET_OS_OSX
204 #if __has_feature(ptrauth_calls)
205 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
206 #endif /* __has_feature(ptrauth_calls) */
207 
208 #if DEBUG || DEVELOPMENT
209 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
210 #endif /* DEBUG || DEVELOPMENT */
211 #endif /* XNU_TARGET_OS_OSX */
212 
213 #if DEVELOPMENT || DEBUG
214 os_log_t exec_log_handle = NULL;
215 #define EXEC_LOG(fmt, ...)      \
216 do {    \
217 	if (exec_log_handle) {      \
218 	        os_log_with_type(exec_log_handle, OS_LOG_TYPE_INFO, "exec - %s:%d " fmt, __FUNCTION__, __LINE__, ##__VA_ARGS__);    \
219 	}   \
220 } while (0)
221 #else /* DEVELOPMENT || DEBUG */
222 #define EXEC_LOG(fmt, ...)  do { } while (0)
223 #endif /* DEVELOPMENT || DEBUG */
224 
225 #if CONFIG_DTRACE
226 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
227 extern void dtrace_proc_exec(proc_t);
228 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
229 
230 /*
231  * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
232  * we will store its value before actually calling it.
233  */
234 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
235 
236 #include <sys/dtrace_ptss.h>
237 #endif
238 
239 #if __has_feature(ptrauth_calls)
240 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
241     "vm_shared_region_per_team_id", 1);
242 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
243     "vm_shared_region_by_entitlement", 1);
244 
245 /* Upon userland request, reslide the shared cache. */
246 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
247     "vm_shared_region_reslide_aslr",
248 #if CONFIG_RESLIDE_SHARED_CACHE
249     1
250 #else
251     0
252 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
253     );
254 
255 /*
256  * Flag to control what processes should get shared cache randomize resliding
257  * after a fault in the shared cache region:
258  *
259  * 0 - all processes get a new randomized slide
260  * 1 - only platform processes get a new randomized slide
261  */
262 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
263     "vm_shared_region_reslide_restrict", 1);
264 
265 #if DEVELOPMENT || DEBUG
266 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
267     CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
268 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
269     CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
270 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
271     CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
272 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
273     CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
274 #endif
275 #endif /* __has_feature(ptrauth_calls) */
276 
277 #if DEVELOPMENT || DEBUG
278 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", true);
279 #else
280 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", false);
281 #endif
282 extern kern_return_t kern_register_userspace_coredump(task_t task, const char * name);
283 #define USERSPACE_COREDUMP_PANIC_ENTITLEMENT "com.apple.private.enable-coredump-on-panic"
284 #define USERSPACE_COREDUMP_PANIC_SEED_ENTITLEMENT \
285 	"com.apple.private.enable-coredump-on-panic-seed-privacy-approved"
286 
287 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
288 extern void task_set_did_exec_flag(task_t task);
289 extern void task_clear_exec_copy_flag(task_t task);
290 proc_t proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task,
291     task_t new_task, struct image_params *imgp, void **inherit);
292 boolean_t task_is_active(task_t);
293 boolean_t thread_is_active(thread_t thread);
294 void thread_copy_resource_info(thread_t dst_thread, thread_t src_thread);
295 void *ipc_importance_exec_switch_task(task_t old_task, task_t new_task);
296 extern void ipc_importance_release(void *elem);
297 extern boolean_t task_has_watchports(task_t task);
298 extern void task_set_no_smt(task_t task);
299 #if defined(HAS_APPLE_PAC)
300 char *task_get_vm_shared_region_id_and_jop_pid(task_t task, uint64_t *jop_pid);
301 #endif
302 task_t convert_port_to_task(ipc_port_t port);
303 
304 #if CONFIG_EXCLAVES
305 int task_add_conclave(task_t task, void *vnode, int64_t off, const char *task_conclave_id);
306 kern_return_t task_inherit_conclave(task_t old_task, task_t new_task, void *vnode, int64_t off);
307 #endif /* CONFIG_EXCLAVES */
308 
309 /*
310  * Mach things for which prototypes are unavailable from Mach headers
311  */
312 extern void ipc_task_enable(task_t task);
313 extern void ipc_task_reset(task_t task);
314 extern void ipc_thread_reset(thread_t thread);
315 
316 #if DEVELOPMENT || DEBUG
317 void task_importance_update_owner_info(task_t);
318 #endif
319 
320 extern struct savearea *get_user_regs(thread_t);
321 
322 __attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
323 
324 #include <kern/thread.h>
325 #include <kern/task.h>
326 #include <kern/ast.h>
327 #include <kern/mach_loader.h>
328 #include <kern/mach_fat.h>
329 #include <mach-o/fat.h>
330 #include <mach-o/loader.h>
331 #include <machine/vmparam.h>
332 #include <sys/imgact.h>
333 
334 #include <sys/sdt.h>
335 
336 
337 /*
338  * EAI_ITERLIMIT	The maximum number of times to iterate an image
339  *			activator in exec_activate_image() before treating
340  *			it as malformed/corrupt.
341  */
342 #define EAI_ITERLIMIT           3
343 
344 /*
345  * For #! interpreter parsing
346  */
347 #define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
348 #define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
349 
350 extern vm_map_t bsd_pageable_map;
351 extern const struct fileops vnops;
352 extern int nextpidversion;
353 
354 
355 #define USER_ADDR_ALIGN(addr, val) \
356 	( ( (user_addr_t)(addr) + (val) - 1) \
357 	        & ~((val) - 1) )
358 
359 /*
360  * For subsystem root support
361  */
362 #define SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT "com.apple.private.spawn-subsystem-root"
363 
364 /*
365  * Allow setting p_crash_behavior to trigger panic on crash
366  */
367 #define SPAWN_SET_PANIC_CRASH_BEHAVIOR "com.apple.private.spawn-panic-crash-behavior"
368 
369 /* Platform Code Exec Logging */
370 static int platform_exec_logging = 0;
371 
372 SYSCTL_DECL(_security_mac);
373 
374 SYSCTL_INT(_security_mac, OID_AUTO, platform_exec_logging, CTLFLAG_RW, &platform_exec_logging, 0,
375     "log cdhashes for all platform binary executions");
376 
377 static os_log_t peLog = OS_LOG_DEFAULT;
378 
379 
380 struct exception_port_action_t {
381 	ipc_port_t port;
382 	_ps_port_action_t *port_action;
383 };
384 
385 struct exec_port_actions {
386 	uint32_t exception_port_count;
387 	uint32_t portwatch_count;
388 	uint32_t registered_count;
389 	struct exception_port_action_t *excport_array;
390 	ipc_port_t *portwatch_array;
391 	ipc_port_t registered_array[TASK_PORT_REGISTER_MAX];
392 };
393 
394 struct image_params;    /* Forward */
395 static int exec_activate_image(struct image_params *imgp);
396 static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
397 static int load_return_to_errno(load_return_t lrtn);
398 static int execargs_alloc(struct image_params *imgp);
399 static int execargs_free(struct image_params *imgp);
400 static int exec_check_permissions(struct image_params *imgp);
401 static int exec_extract_strings(struct image_params *imgp);
402 static int exec_add_apple_strings(struct image_params *imgp, const load_result_t *load_result, task_t task);
403 static int exec_handle_sugid(struct image_params *imgp);
404 static int sugid_scripts = 0;
405 SYSCTL_INT(_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
406 static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
407 static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
408 static void exec_resettextvp(proc_t, struct image_params *);
409 static int process_signature(proc_t, struct image_params *);
410 static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
411 static errno_t exec_handle_port_actions(struct image_params *imgp,
412     struct exec_port_actions *port_actions);
413 static errno_t exec_handle_exception_port_actions(const struct image_params *imgp,
414     const struct exec_port_actions *port_actions);
415 static errno_t exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
416     task_role_t psa_darwin_role, struct exec_port_actions *port_actions);
417 static void exec_port_actions_destroy(struct exec_port_actions *port_actions);
418 
419 /*
420  * exec_add_user_string
421  *
422  * Add the requested string to the string space area.
423  *
424  * Parameters;	struct image_params *		image parameter block
425  *		user_addr_t			string to add to strings area
426  *		int				segment from which string comes
427  *		boolean_t			TRUE if string contributes to NCARGS
428  *
429  * Returns:	0			Success
430  *		!0			Failure errno from copyinstr()
431  *
432  * Implicit returns:
433  *		(imgp->ip_strendp)	updated location of next add, if any
434  *		(imgp->ip_strspace)	updated byte count of space remaining
435  *		(imgp->ip_argspace) updated byte count of space in NCARGS
436  */
437 __attribute__((noinline))
438 static int
exec_add_user_string(struct image_params * imgp,user_addr_t str,int seg,boolean_t is_ncargs)439 exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
440 {
441 	int error = 0;
442 
443 	do {
444 		size_t len = 0;
445 		int space;
446 
447 		if (is_ncargs) {
448 			space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
449 		} else {
450 			space = imgp->ip_strspace;
451 		}
452 
453 		if (space <= 0) {
454 			error = E2BIG;
455 			break;
456 		}
457 
458 		if (!UIO_SEG_IS_USER_SPACE(seg)) {
459 			char *kstr = CAST_DOWN(char *, str);     /* SAFE */
460 			error = copystr(kstr, imgp->ip_strendp, space, &len);
461 		} else {
462 			error = copyinstr(str, imgp->ip_strendp, space, &len);
463 		}
464 
465 		imgp->ip_strendp += len;
466 		imgp->ip_strspace -= len;
467 		if (is_ncargs) {
468 			imgp->ip_argspace -= len;
469 		}
470 	} while (error == ENAMETOOLONG);
471 
472 	return error;
473 }
474 
475 /*
476  * dyld is now passed the executable path as a getenv-like variable
477  * in the same fashion as the stack_guard and malloc_entropy keys.
478  */
479 #define EXECUTABLE_KEY "executable_path="
480 
481 /*
482  * exec_save_path
483  *
484  * To support new app package launching for Mac OS X, the dyld needs the
485  * first argument to execve() stored on the user stack.
486  *
487  * Save the executable path name at the bottom of the strings area and set
488  * the argument vector pointer to the location following that to indicate
489  * the start of the argument and environment tuples, setting the remaining
490  * string space count to the size of the string area minus the path length.
491  *
492  * Parameters;	struct image_params *		image parameter block
493  *		char *				path used to invoke program
494  *		int				segment from which path comes
495  *
496  * Returns:	int			0	Success
497  *		EFAULT				Bad address
498  *	copy[in]str:EFAULT			Bad address
499  *	copy[in]str:ENAMETOOLONG		Filename too long
500  *
501  * Implicit returns:
502  *		(imgp->ip_strings)		saved path
503  *		(imgp->ip_strspace)		space remaining in ip_strings
504  *		(imgp->ip_strendp)		start of remaining copy area
505  *		(imgp->ip_argspace)		space remaining of NCARGS
506  *		(imgp->ip_applec)		Initial applev[0]
507  *
508  * Note:	We have to do this before the initial namei() since in the
509  *		path contains symbolic links, namei() will overwrite the
510  *		original path buffer contents.  If the last symbolic link
511  *		resolved was a relative pathname, we would lose the original
512  *		"path", which could be an absolute pathname. This might be
513  *		unacceptable for dyld.
514  */
515 static int
exec_save_path(struct image_params * imgp,user_addr_t path,int seg,const char ** excpath)516 exec_save_path(struct image_params *imgp, user_addr_t path, int seg, const char **excpath)
517 {
518 	int error;
519 	size_t len;
520 	char *kpath;
521 
522 	// imgp->ip_strings can come out of a cache, so we need to obliterate the
523 	// old path.
524 	memset(imgp->ip_strings, '\0', strlen(EXECUTABLE_KEY) + MAXPATHLEN);
525 
526 	len = MIN(MAXPATHLEN, imgp->ip_strspace);
527 
528 	switch (seg) {
529 	case UIO_USERSPACE32:
530 	case UIO_USERSPACE64:   /* Same for copyin()... */
531 		error = copyinstr(path, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
532 		break;
533 	case UIO_SYSSPACE:
534 		kpath = CAST_DOWN(char *, path); /* SAFE */
535 		error = copystr(kpath, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
536 		break;
537 	default:
538 		error = EFAULT;
539 		break;
540 	}
541 
542 	if (!error) {
543 		bcopy(EXECUTABLE_KEY, imgp->ip_strings, strlen(EXECUTABLE_KEY));
544 		len += strlen(EXECUTABLE_KEY);
545 
546 		imgp->ip_strendp += len;
547 		imgp->ip_strspace -= len;
548 
549 		if (excpath) {
550 			*excpath = imgp->ip_strings + strlen(EXECUTABLE_KEY);
551 		}
552 	}
553 
554 	return error;
555 }
556 
557 /*
558  * exec_reset_save_path
559  *
560  * If we detect a shell script, we need to reset the string area
561  * state so that the interpreter can be saved onto the stack.
562  *
563  * Parameters;	struct image_params *		image parameter block
564  *
565  * Returns:	int			0	Success
566  *
567  * Implicit returns:
568  *		(imgp->ip_strings)		saved path
569  *		(imgp->ip_strspace)		space remaining in ip_strings
570  *		(imgp->ip_strendp)		start of remaining copy area
571  *		(imgp->ip_argspace)		space remaining of NCARGS
572  *
573  */
574 static int
exec_reset_save_path(struct image_params * imgp)575 exec_reset_save_path(struct image_params *imgp)
576 {
577 	imgp->ip_strendp = imgp->ip_strings;
578 	imgp->ip_argspace = NCARGS;
579 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
580 
581 	return 0;
582 }
583 
584 /*
585  * exec_shell_imgact
586  *
587  * Image activator for interpreter scripts.  If the image begins with
588  * the characters "#!", then it is an interpreter script.  Verify the
589  * length of the script line indicating the interpreter is not in
590  * excess of the maximum allowed size.  If this is the case, then
591  * break out the arguments, if any, which are separated by white
592  * space, and copy them into the argument save area as if they were
593  * provided on the command line before all other arguments.  The line
594  * ends when we encounter a comment character ('#') or newline.
595  *
596  * Parameters;	struct image_params *	image parameter block
597  *
598  * Returns:	-1			not an interpreter (keep looking)
599  *		-3			Success: interpreter: relookup
600  *		>0			Failure: interpreter: error number
601  *
602  * A return value other than -1 indicates subsequent image activators should
603  * not be given the opportunity to attempt to activate the image.
604  */
605 static int
exec_shell_imgact(struct image_params * imgp)606 exec_shell_imgact(struct image_params *imgp)
607 {
608 	char *vdata = imgp->ip_vdata;
609 	char *ihp;
610 	char *line_startp, *line_endp;
611 	char *interp;
612 
613 	/*
614 	 * Make sure it's a shell script.  If we've already redirected
615 	 * from an interpreted file once, don't do it again.
616 	 */
617 	if (vdata[0] != '#' ||
618 	    vdata[1] != '!' ||
619 	    (imgp->ip_flags & IMGPF_INTERPRET) != 0) {
620 		return -1;
621 	}
622 
623 	if (imgp->ip_origcputype != 0) {
624 		/* Fat header previously matched, don't allow shell script inside */
625 		return -1;
626 	}
627 
628 	imgp->ip_flags |= IMGPF_INTERPRET;
629 	imgp->ip_interp_sugid_fd = -1;
630 	imgp->ip_interp_buffer[0] = '\0';
631 
632 	/* Check to see if SUGID scripts are permitted.  If they aren't then
633 	 * clear the SUGID bits.
634 	 * imgp->ip_vattr is known to be valid.
635 	 */
636 	if (sugid_scripts == 0) {
637 		imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
638 	}
639 
640 	/* Try to find the first non-whitespace character */
641 	for (ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++) {
642 		if (IS_EOL(*ihp)) {
643 			/* Did not find interpreter, "#!\n" */
644 			return ENOEXEC;
645 		} else if (IS_WHITESPACE(*ihp)) {
646 			/* Whitespace, like "#!    /bin/sh\n", keep going. */
647 		} else {
648 			/* Found start of interpreter */
649 			break;
650 		}
651 	}
652 
653 	if (ihp == &vdata[IMG_SHSIZE]) {
654 		/* All whitespace, like "#!           " */
655 		return ENOEXEC;
656 	}
657 
658 	line_startp = ihp;
659 
660 	/* Try to find the end of the interpreter+args string */
661 	for (; ihp < &vdata[IMG_SHSIZE]; ihp++) {
662 		if (IS_EOL(*ihp)) {
663 			/* Got it */
664 			break;
665 		} else {
666 			/* Still part of interpreter or args */
667 		}
668 	}
669 
670 	if (ihp == &vdata[IMG_SHSIZE]) {
671 		/* A long line, like "#! blah blah blah" without end */
672 		return ENOEXEC;
673 	}
674 
675 	/* Backtrack until we find the last non-whitespace */
676 	while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
677 		ihp--;
678 	}
679 
680 	/* The character after the last non-whitespace is our logical end of line */
681 	line_endp = ihp + 1;
682 
683 	/*
684 	 * Now we have pointers to the usable part of:
685 	 *
686 	 * "#!  /usr/bin/int first    second   third    \n"
687 	 *      ^ line_startp                       ^ line_endp
688 	 */
689 
690 	/* copy the interpreter name */
691 	interp = imgp->ip_interp_buffer;
692 	for (ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++) {
693 		*interp++ = *ihp;
694 	}
695 	*interp = '\0';
696 
697 	exec_reset_save_path(imgp);
698 	exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
699 	    UIO_SYSSPACE, NULL);
700 
701 	/* Copy the entire interpreter + args for later processing into argv[] */
702 	interp = imgp->ip_interp_buffer;
703 	for (ihp = line_startp; (ihp < line_endp); ihp++) {
704 		*interp++ = *ihp;
705 	}
706 	*interp = '\0';
707 
708 #if CONFIG_SETUID
709 	/*
710 	 * If we have an SUID or SGID script, create a file descriptor
711 	 * from the vnode and pass /dev/fd/%d instead of the actual
712 	 * path name so that the script does not get opened twice
713 	 */
714 	if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
715 		proc_t p;
716 		struct fileproc *fp;
717 		int fd;
718 		int error;
719 
720 		p = vfs_context_proc(imgp->ip_vfs_context);
721 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &fd);
722 		if (error) {
723 			return error;
724 		}
725 
726 		fp->fp_glob->fg_flag = FREAD;
727 		fp->fp_glob->fg_ops = &vnops;
728 		fp_set_data(fp, imgp->ip_vp);
729 
730 		proc_fdlock(p);
731 		procfdtbl_releasefd(p, fd, NULL);
732 		fp_drop(p, fd, fp, 1);
733 		proc_fdunlock(p);
734 		vnode_ref(imgp->ip_vp);
735 
736 		imgp->ip_interp_sugid_fd = fd;
737 	}
738 #endif /* CONFIG_SETUID */
739 
740 	return -3;
741 }
742 
743 
744 
745 /*
746  * exec_fat_imgact
747  *
748  * Image activator for fat 1.0 binaries.  If the binary is fat, then we
749  * need to select an image from it internally, and make that the image
750  * we are going to attempt to execute.  At present, this consists of
751  * reloading the first page for the image with a first page from the
752  * offset location indicated by the fat header.
753  *
754  * Parameters;	struct image_params *	image parameter block
755  *
756  * Returns:	-1			not a fat binary (keep looking)
757  *		-2			Success: encapsulated binary: reread
758  *		>0			Failure: error number
759  *
760  * Important:	This image activator is byte order neutral.
761  *
762  * Note:	A return value other than -1 indicates subsequent image
763  *		activators should not be given the opportunity to attempt
764  *		to activate the image.
765  *
766  *              If we find an encapsulated binary, we make no assertions
767  *		about its  validity; instead, we leave that up to a rescan
768  *		for an activator to claim it, and, if it is claimed by one,
769  *		that activator is responsible for determining validity.
770  */
771 static int
exec_fat_imgact(struct image_params * imgp)772 exec_fat_imgact(struct image_params *imgp)
773 {
774 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
775 	kauth_cred_t cred = kauth_cred_proc_ref(p);
776 	struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
777 	struct _posix_spawnattr *psa = NULL;
778 	struct fat_arch fat_arch;
779 	int resid, error;
780 	load_return_t lret;
781 
782 	if (imgp->ip_origcputype != 0) {
783 		/* Fat header previously matched, don't allow another fat file inside */
784 		error = -1; /* not claimed */
785 		goto bad;
786 	}
787 
788 	/* Make sure it's a fat binary */
789 	if (OSSwapBigToHostInt32(fat_header->magic) != FAT_MAGIC) {
790 		error = -1; /* not claimed */
791 		goto bad;
792 	}
793 
794 	/* imgp->ip_vdata has PAGE_SIZE, zerofilled if the file is smaller */
795 	lret = fatfile_validate_fatarches((vm_offset_t)fat_header, PAGE_SIZE,
796 	    (off_t)imgp->ip_vattr->va_data_size);
797 	if (lret != LOAD_SUCCESS) {
798 		error = load_return_to_errno(lret);
799 		goto bad;
800 	}
801 
802 	/* If posix_spawn binprefs exist, respect those prefs. */
803 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
804 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
805 		uint32_t pr = 0;
806 
807 		/* Check each preference listed against all arches in header */
808 		for (pr = 0; pr < NBINPREFS; pr++) {
809 			cpu_type_t pref = psa->psa_binprefs[pr];
810 			cpu_type_t subpref = psa->psa_subcpuprefs[pr];
811 
812 			if (pref == 0) {
813 				/* No suitable arch in the pref list */
814 				error = EBADARCH;
815 				goto bad;
816 			}
817 
818 			if (pref == CPU_TYPE_ANY) {
819 				/* Fall through to regular grading */
820 				goto regular_grading;
821 			}
822 
823 			lret = fatfile_getbestarch_for_cputype(pref,
824 			    subpref,
825 			    (vm_offset_t)fat_header,
826 			    PAGE_SIZE,
827 			    imgp,
828 			    &fat_arch);
829 			if (lret == LOAD_SUCCESS) {
830 				goto use_arch;
831 			}
832 		}
833 
834 		/* Requested binary preference was not honored */
835 		error = EBADEXEC;
836 		goto bad;
837 	}
838 
839 regular_grading:
840 	/* Look up our preferred architecture in the fat file. */
841 	lret = fatfile_getbestarch((vm_offset_t)fat_header,
842 	    PAGE_SIZE,
843 	    imgp,
844 	    &fat_arch,
845 	    (p->p_flag & P_AFFINITY) != 0);
846 	if (lret != LOAD_SUCCESS) {
847 		error = load_return_to_errno(lret);
848 		goto bad;
849 	}
850 
851 use_arch:
852 	/* Read the Mach-O header out of fat_arch */
853 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
854 	    PAGE_SIZE, fat_arch.offset,
855 	    UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
856 	    cred, &resid, p);
857 	if (error) {
858 		if (error == ERESTART) {
859 			error = EINTR;
860 		}
861 		goto bad;
862 	}
863 
864 	if (resid) {
865 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
866 	}
867 
868 	/* Success.  Indicate we have identified an encapsulated binary */
869 	error = -2;
870 	imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
871 	imgp->ip_arch_size = (user_size_t)fat_arch.size;
872 	imgp->ip_origcputype = fat_arch.cputype;
873 	imgp->ip_origcpusubtype = fat_arch.cpusubtype;
874 
875 bad:
876 	kauth_cred_unref(&cred);
877 	return error;
878 }
879 
880 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)881 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
882 {
883 	int ret;
884 
885 	(void)task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0, false);
886 	task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
887 	if (result->is_64bit_addr) {
888 		OSBitOrAtomic(P_LP64, &p->p_flag);
889 		get_bsdthread_info(thread)->uu_flag |= UT_LP64;
890 	} else {
891 		OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
892 		get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
893 	}
894 	task_set_mach_header_address(task, result->mach_header);
895 
896 	ret = thread_state_initialize(thread);
897 	if (ret != KERN_SUCCESS) {
898 		return ret;
899 	}
900 
901 	if (result->threadstate) {
902 		uint32_t *ts = result->threadstate;
903 		uint32_t total_size = (uint32_t)result->threadstate_sz;
904 
905 		while (total_size > 0) {
906 			uint32_t flavor = *ts++;
907 			uint32_t size = *ts++;
908 
909 			ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
910 			if (ret) {
911 				return ret;
912 			}
913 			ts += size;
914 			total_size -= (size + 2) * sizeof(uint32_t);
915 		}
916 	}
917 
918 	thread_setentrypoint(thread, result->entry_point);
919 
920 	return KERN_SUCCESS;
921 }
922 
923 #if (DEVELOPMENT || DEBUG)
924 extern char panic_on_proc_crash[];
925 extern int use_panic_on_proc_crash;
926 
927 extern char panic_on_proc_exit[];
928 extern int use_panic_on_proc_exit;
929 
930 extern char panic_on_proc_spawn_fail[];
931 extern int use_panic_on_proc_spawn_fail;
932 
933 static inline void
set_crash_behavior_from_bootarg(proc_t p)934 set_crash_behavior_from_bootarg(proc_t p)
935 {
936 	if (use_panic_on_proc_crash && strcmp(p->p_comm, panic_on_proc_crash) == 0) {
937 		printf("will panic on proc crash: %s\n", p->p_comm);
938 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_CRASH;
939 	}
940 
941 	if (use_panic_on_proc_exit && strcmp(p->p_comm, panic_on_proc_exit) == 0) {
942 		printf("will panic on proc exit: %s\n", p->p_comm);
943 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_EXIT;
944 	}
945 
946 	if (use_panic_on_proc_spawn_fail && strcmp(p->p_comm, panic_on_proc_spawn_fail) == 0) {
947 		printf("will panic on proc spawn fail: %s\n", p->p_comm);
948 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_SPAWN_FAIL;
949 	}
950 }
951 #endif
952 
953 void
set_proc_name(struct image_params * imgp,proc_t p)954 set_proc_name(struct image_params *imgp, proc_t p)
955 {
956 	uint64_t buflen = imgp->ip_ndp->ni_cnd.cn_namelen;
957 	const int p_name_len = sizeof(p->p_name) - 1;
958 	const int p_comm_len = sizeof(p->p_comm) - 1;
959 
960 	if (buflen > p_name_len) {
961 		buflen = p_name_len;
962 	}
963 
964 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name, buflen);
965 	p->p_name[buflen] = '\0';
966 
967 	if (buflen > p_comm_len) {
968 		static_assert(MAXCOMLEN + 1 == sizeof(p->p_comm));
969 		buflen = p_comm_len;
970 	}
971 
972 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm, buflen);
973 	p->p_comm[buflen] = '\0';
974 
975 #if (DEVELOPMENT || DEBUG)
976 	/*
977 	 * This happens during image activation, so the crash behavior flags from
978 	 * posix_spawn will have already been set. So we don't have to worry about
979 	 * this being overridden.
980 	 */
981 	set_crash_behavior_from_bootarg(p);
982 #endif
983 }
984 
985 #if __has_feature(ptrauth_calls)
986 /**
987  * Returns a team ID string that may be used to assign a shared region.
988  *
989  * Platform binaries do not have team IDs and will return NULL.  Non-platform
990  * binaries without a team ID will be assigned an artificial team ID of ""
991  * (empty string) so that they will not be assigned to the default shared
992  * region.
993  *
994  * @param imgp image parameter block
995  * @return NULL if this is a platform binary, or an appropriate team ID string
996  *         otherwise
997  */
998 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)999 get_teamid_for_shared_region(struct image_params *imgp)
1000 {
1001 	assert(imgp->ip_vp != NULL);
1002 
1003 	const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
1004 	if (ret) {
1005 		return ret;
1006 	}
1007 
1008 	struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
1009 	if (csblob_get_platform_binary(blob)) {
1010 		return NULL;
1011 	} else {
1012 		static const char *NO_TEAM_ID = "";
1013 		return NO_TEAM_ID;
1014 	}
1015 }
1016 
1017 /**
1018  * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
1019  *
1020  * @param cpusubtype Mach-O style CPU subtype
1021  * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
1022  */
1023 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)1024 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
1025 {
1026 	int ptrauth_abi_version = (int)CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype);
1027 	return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1028 	       (ptrauth_abi_version >= CPU_SUBTYPE_ARM64_PTR_AUTHV0_VERSION &&
1029 	       ptrauth_abi_version <= CPU_SUBTYPE_ARM64_PTR_AUTH_MAX_PREFERRED_VERSION);
1030 }
1031 
1032 #endif /* __has_feature(ptrauth_calls) */
1033 
1034 /**
1035  * Returns whether a type/subtype slice matches the requested
1036  * type/subtype.
1037  *
1038  * @param mask Bits to mask from the requested/tested cpu type
1039  * @param req_cpu Requested cpu type
1040  * @param req_subcpu Requested cpu subtype
1041  * @param test_cpu Tested slice cpu type
1042  * @param test_subcpu Tested slice cpu subtype
1043  */
1044 boolean_t
binary_match(cpu_type_t mask,cpu_type_t req_cpu,cpu_subtype_t req_subcpu,cpu_type_t test_cpu,cpu_subtype_t test_subcpu)1045 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
1046     cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
1047     cpu_subtype_t test_subcpu)
1048 {
1049 	if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
1050 		return FALSE;
1051 	}
1052 
1053 	test_subcpu &= ~CPU_SUBTYPE_MASK;
1054 	req_subcpu  &= ~CPU_SUBTYPE_MASK;
1055 
1056 	if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
1057 		return FALSE;
1058 	}
1059 
1060 	return TRUE;
1061 }
1062 
1063 
1064 /*
1065  * Check entitlements to see if this is a platform restrictions binary.
1066  * Save this in load_result until later for two purposes:
1067  * 1. We can mark the task at a certain security level once it's been created
1068  * 2. We can propagate which entitlements are present to the apple array
1069  */
1070 static inline void
encode_HR_entitlement(const char * entitlement,hardened_browser_flags_t mask,const struct image_params * imgp,load_result_t * load_result)1071 encode_HR_entitlement(const char *entitlement, hardened_browser_flags_t mask,
1072     const struct image_params *imgp, load_result_t *load_result)
1073 {
1074 	if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
1075 		load_result->hardened_browser |= mask;
1076 	}
1077 }
1078 
1079 /*
1080  * If the passed in executable's vnode should use the RSR
1081  * shared region, then this should return TRUE, otherwise, return FALSE.
1082  */
1083 static uint32_t rsr_current_version = 0;
1084 boolean_t (*rsr_check_vnode)(void *vnode) = NULL;
1085 
1086 boolean_t
vnode_is_rsr(vnode_t vp)1087 vnode_is_rsr(vnode_t vp)
1088 {
1089 	if (!(vnode_isreg(vp) && vnode_tag(vp) == VT_APFS)) {
1090 		return FALSE;
1091 	}
1092 
1093 	if (rsr_check_vnode != NULL && rsr_check_vnode((void *)vp)) {
1094 		return TRUE;
1095 	}
1096 	return FALSE;
1097 }
1098 
1099 static struct {
1100 	char *legacy;
1101 	char *security;
1102 } exec_security_mitigation_entitlement[] = {
1103 	/* The following entries must match the enum declaration in kern_exec_internal.h */
1104 	[HARDENED_PROCESS] = {
1105 		"com.apple.developer.hardened-process",
1106 		"com.apple.security.hardened-process"
1107 	},
1108 	[HARDENED_HEAP] = {
1109 		"com.apple.developer.hardened-process.hardened-heap",
1110 		"com.apple.security.hardened-process.hardened-heap"
1111 	},
1112 	[TPRO] = {
1113 		NULL,
1114 		"com.apple.security.hardened-process.dyld-ro",
1115 	},
1116 #if HAS_MTE
1117 	[CHECKED_ALLOCATIONS] = {
1118 		"com.apple.developer.hardened-process.checked-allocations",
1119 		"com.apple.security.hardened-process.checked-allocations"
1120 	},
1121 	[CHECKED_ALLOCATIONS_PURE_DATA] = {
1122 		NULL,
1123 		"com.apple.security.hardened-process.checked-allocations.enable-pure-data"
1124 	},
1125 	[CHECKED_ALLOCATIONS_NO_TAGGED_RECEIVE] = {
1126 		NULL,
1127 		"com.apple.security.hardened-process.checked-allocations.no-tagged-receive"
1128 	},
1129 	[CHECKED_ALLOCATIONS_SOFT_MODE] = {
1130 		NULL,
1131 		"com.apple.security.hardened-process.checked-allocations.soft-mode"
1132 	},
1133 #endif /* HAS_MTE */
1134 	[NO_GUARD_OBJECTS] = {
1135 		NULL,
1136 		"com.apple.security.hardened-process.no-guard-objects"
1137 	}
1138 };
1139 
1140 /*
1141  * Platform Restrictions
1142  *
1143  * This mitigation opts you into the grab bag of various kernel mitigations
1144  * including IPC security restrictions
1145  * The presence of the entitlement opts the binary into the feature.
1146  * The entitlement is an <integer> entitlement containing a version number
1147  * for the platform restrictions you are opting into.
1148  */
1149 #define SPAWN_ENABLE_PLATFORM_RESTRICTIONS "com.apple.security.hardened-process.platform-restrictions"
1150 
1151 /* See kern_exec_internal.h for the extensive documentation. */
1152 exec_security_err_t
exec_check_security_entitlement(struct image_params * imgp,exec_security_mitigation_entitlement_t entitlement)1153 exec_check_security_entitlement(struct image_params *imgp,
1154     exec_security_mitigation_entitlement_t entitlement)
1155 {
1156 	bool has_legacy_entitlement = false, has_security_entitlement = false;
1157 	assert(exec_security_mitigation_entitlement[entitlement].security != NULL);
1158 
1159 	if (exec_security_mitigation_entitlement[entitlement].legacy != NULL) {
1160 		has_legacy_entitlement =
1161 		    IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
1162 		    exec_security_mitigation_entitlement[entitlement].legacy);
1163 	}
1164 
1165 	has_security_entitlement =
1166 	    IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
1167 	    exec_security_mitigation_entitlement[entitlement].security);
1168 
1169 	/* If both entitlements are present, this is an invalid configuration. */
1170 	if (has_legacy_entitlement && has_security_entitlement) {
1171 		EXEC_LOG("Binary has both legacy (%s) and security (%s) entitlements\n",
1172 		    exec_security_mitigation_entitlement[entitlement].legacy,
1173 		    exec_security_mitigation_entitlement[entitlement].security);
1174 
1175 		return EXEC_SECURITY_INVALID_CONFIG;
1176 	}
1177 
1178 	if (has_legacy_entitlement || has_security_entitlement) {
1179 		return EXEC_SECURITY_ENTITLED;
1180 	}
1181 
1182 	return EXEC_SECURITY_NOT_ENTITLED;
1183 }
1184 
1185 
1186 /*
1187  * Entitled binaries get hardened_heap
1188  */
1189 static inline errno_t
imgact_setup_hardened_heap(struct image_params * imgp,task_t task)1190 imgact_setup_hardened_heap(struct image_params *imgp, task_t task)
1191 {
1192 	exec_security_err_t ret = exec_check_security_entitlement(imgp, HARDENED_HEAP);
1193 	if (ret == EXEC_SECURITY_ENTITLED) {
1194 		task_set_hardened_heap(task);
1195 	} else {
1196 		task_clear_hardened_heap(task);
1197 	}
1198 	switch (ret) {
1199 	case EXEC_SECURITY_INVALID_CONFIG:
1200 		return EINVAL;
1201 	case EXEC_SECURITY_ENTITLED:
1202 	case EXEC_SECURITY_NOT_ENTITLED:
1203 		return 0;
1204 	}
1205 }
1206 
1207 /*
1208  * Configure the platform restrictions security features on the task
1209  * This must be done before `ipc_task_enable` so that the bits
1210  * can be propagated to the ipc space.
1211  *
1212  * Requires `exectextresetvp` to be called on `task` previously so
1213  * that we can use the `IOTaskGetEntitlement` API
1214  */
1215 static inline void
exec_setup_platform_restrictions(task_t task)1216 exec_setup_platform_restrictions(task_t task)
1217 {
1218 	uint64_t value = 0;
1219 	/* Set platform restrictions version */
1220 	if (task_get_platform_binary(task)) {
1221 		task_set_platform_restrictions_version(task, 2);
1222 	} else if (IOTaskGetIntegerEntitlement(task, SPAWN_ENABLE_PLATFORM_RESTRICTIONS, &value) &&
1223 	    value > 1) {
1224 		task_set_platform_restrictions_version(task, value);
1225 	}
1226 }
1227 
1228 #if HAS_MTE || HAS_MTE_EMULATION_SHIMS
1229 
1230 #if DEVELOPMENT || DEBUG
1231 static inline void config_sec_inheritance(task_t, task_t);
1232 #endif /* DEVELOPMENT || DEBUG */
1233 static inline void config_sec_spawnflags(load_result_t *load_result,
1234     struct _posix_spawnattr *, task_t);
1235 
1236 #if HAS_MTE
1237 
1238 static inline errno_t config_checked_allocations_entitlements(struct image_params *,
1239     load_result_t *, task_t, struct cs_blob *, proc_t);
1240 
1241 static inline exec_security_err_t
imgact_setup_has_checked_allocations_entitlement(struct image_params * imgp,load_result_t * load_result,__unused task_t new_task,__unused struct cs_blob * cs_blob)1242 imgact_setup_has_checked_allocations_entitlement(struct image_params *imgp, load_result_t *load_result,
1243     __unused task_t new_task, __unused struct cs_blob *cs_blob)
1244 {
1245 	/* First-party DriverKit always gets MTE regardless of our normal entitlement knobs */
1246 	if (load_result->platform_binary && IOVnodeHasEntitlement(imgp->ip_vp,
1247 	    (int64_t)imgp->ip_arch_offset, kIODriverKitEntitlementKey)) {
1248 		/* In soft mode, to mitigate risks on the build */
1249 		EXEC_LOG("Enabling MTE because we're launching a first-party dext");
1250 		return EXEC_SECURITY_ENTITLED;
1251 	}
1252 
1253 	/* If not a hardened-process, bail out. */
1254 	if (!load_result->hardened_process_version) {
1255 		return EXEC_SECURITY_NOT_ENTITLED;
1256 	}
1257 
1258 	/* Check the entitlement. */
1259 	exec_security_err_t ret = exec_check_security_entitlement(imgp, CHECKED_ALLOCATIONS);
1260 
1261 	/* Bail out early on invalid configuration. These will fail execution. */
1262 	if (ret == EXEC_SECURITY_INVALID_CONFIG) {
1263 		return ret;
1264 	}
1265 
1266 	/*
1267 	 * We need a couple of extra checks for first party binaries, mostly around
1268 	 * AMFI and reporting early (forbidden) usage of the entitlement.
1269 	 */
1270 	if (load_result->platform_binary) {
1271 #if KERN_AMFI_SUPPORTS_MTE >= 2
1272 		if (__improbable(amfi->has_mte_opt_out && amfi->has_mte_opt_out(cs_blob))) {
1273 			EXEC_LOG("Binary checked-allocations enablement was denied by AMFI static list\n");
1274 			return EXEC_SECURITY_NOT_ENTITLED;
1275 		}
1276 #endif /* KERN_AMFI_SUPPORTS_MTE */
1277 
1278 		/*
1279 		 * At this stage we are an hardened-process and AMFI hasn't said that we should
1280 		 * not enable MTE, therefore we just force enable even if the entitlement is not
1281 		 * present (until we can publicly require checked-allocations to be true).
1282 		 */
1283 		return EXEC_SECURITY_ENTITLED;
1284 	}
1285 
1286 	/*
1287 	 * The third-party flow is more linear: whatever the entitlement said it was the
1288 	 * setting, we'll run with it.
1289 	 */
1290 	return ret;
1291 }
1292 #endif /* HAS_MTE */
1293 
1294 /*
1295  * Checked-allocations is a security feature that leverages MTE (Memory Tagging Extensions)
1296  * inside userspace allocators to protect dynamic memory allocations.
1297  *
1298  * MTE is a hardware security feature available in recent hardware devices. For legacy
1299  * devices, we support an internal-only readiness tool based on Rosetta that aims at
1300  * qualifying binaries for the new hardware, but that is not meant to be used in production.
1301  *
1302  * Checked-allocations enablement (generally referred to as MTE enabled here) and
1303  * configuration is controlled by:
1304  *   - inheritance (debugging feature for bringup/readiness/performance evaluation)
1305  *   - posix_spawn flags (no downgrade flags supported on RELEASE)
1306  *   - entitlements (hardware only, no emulation. Main RELEASE configuration)
1307  *
1308  * The algorithm to decide whether checked-allocations should be enabled on the target
1309  * process is summarized here.
1310  * For Rosetta binaries, only posix_spawn flags are supported.
1311  *
1312  *  ┌────────────────┐                               ┌───────────────┐
1313  *  │  Inheritance   │       ┌───────────────┐       │ Configure MTE │
1314  *  │    enabled?    ├─YES──▶│  Enable MTE   │──────▶│   mirroring   │
1315  *  └──────────┬─────┘       └───────────────┘       │ parent state  │
1316  *             │                                     └───────────────┘
1317  *            NO
1318  *             │
1319  *             │      ┌─────────────────────────────┐
1320  *             └─────▶│posix_spawn explicit enable? │
1321  *                    └──┬─────────────┬────────────┘
1322  *                       │             │
1323  *                       │             │
1324  *                     YES            NO
1325  *                       │             │   ┌──────────────────────────────────┐
1326  * ┌───────────────┐     │             └──▶│ hardened-process entitlement or  │
1327  * │  Enable MTE   │◀────┘                 │   (1p && DriverKit entitlement)? │
1328  * └───────┬───────┘                       └───────────┬─────────────┬────────┘
1329  *         │                                          YES            NO
1330  * ┌───────▼───────┐                                   │             │
1331  * │ Configure MTE │                        ┌──────────▼────┐   ┌────▼─────────┐
1332  * │    through    │                        │  Enable MTE   │   │ Disable MTE  │
1333  * │  posix_spawn  │                        └──────────┬────┘   └──────────────┘
1334  * │     flags     │                                   │
1335  * └───────────────┘                        ┌──────────▼────┐
1336  *                                          │ Configure MTE │
1337  *                                          │    through    │
1338  *                                          │ entitlements  │
1339  *                                          └───────────────┘
1340  *
1341  *
1342  * The above algorithm covers the decision of enabling checked-allocations but doesn't
1343  * cover the configuration options which are described later.
1344  *
1345  * This function returns false only in case POSIX_SPAWN_SECFLAG_EXPLICIT_REQUIRE_ENABLE is passed
1346  * and the binary fails to satisfy the requirement.
1347  */
1348 static inline errno_t
imgact_setup_sec(struct image_params * imgp,__unused load_result_t * load_result,task_t old_task,task_t new_task,__unused vm_map_t new_map,__unused proc_t new_proc)1349 imgact_setup_sec(struct image_params *imgp, __unused load_result_t *load_result, task_t old_task,
1350     task_t new_task, __unused vm_map_t new_map, __unused proc_t new_proc)
1351 {
1352 #if DEVELOPMENT || DEBUG
1353 #if HAS_MTE
1354 	/* Nothing to do if we have disabled MTE system-wide */
1355 	if (!is_mte_enabled) {
1356 		EXEC_LOG("MTE enablement is skipped due to system-wide disablement\n");
1357 		return 0;
1358 	}
1359 #endif /* HAS_MTE */
1360 
1361 #if HAS_MTE_EMULATION_SHIMS
1362 	/* Ignore any emulation attempt if we are not running under Rosetta. */
1363 	if ((imgp->ip_flags & (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA)) == 0) {
1364 		return 0;
1365 	}
1366 #endif /* HAS_MTE_EMULATION_SHIMS */
1367 #endif /* DEVELOPMENT || DEBUG */
1368 
1369 	/* Reset to a clear view on the target task - we'll decide the configuration here. */
1370 	task_clear_sec(new_task);
1371 	task_clear_sec_policy(new_task);
1372 
1373 	/*
1374 	 * If the parent has sec inherit, propagate the security settings.
1375 	 * Inheritance is currently aimed only at debug sessions and will trump
1376 	 * any existing configuration. Inheritance should be seen as the same posix_spawn
1377 	 * flags used to enable it (+ configure the feature) re-applied over and over on
1378 	 * every descendant.
1379 	 */
1380 	if (task_has_sec_inherit(old_task)) {
1381 		EXEC_LOG("Task will be configured based on inheritance\n");
1382 		/* Inheritance propagates to the next task. */
1383 		task_set_sec_inherit(new_task);
1384 
1385 		if (task_has_sec(old_task)) {
1386 			task_set_sec(new_task);
1387 #if DEVELOPMENT || DEBUG
1388 			config_sec_inheritance(old_task, new_task);
1389 #endif /* DEVELOPMENT || DEBUG */
1390 		}
1391 		return 0;
1392 	}
1393 
1394 	/* Check posix_spawn flags now if any */
1395 	struct _posix_spawnattr *px_sa = imgp->ip_px_sa;
1396 
1397 	if (px_sa != NULL) {
1398 #if DEVELOPMENT || DEBUG
1399 		/*
1400 		 * Do we have a request to explicitly disable?
1401 		 */
1402 		if ((px_sa->psa_sec_flags & POSIX_SPAWN_SECFLAG_EXPLICIT_DISABLE) != 0) {
1403 			EXEC_LOG("Task configured to disable the security feature due to posix_spawn\n");
1404 			/* For A/B testing, allow DISABLE to propagate through inheritance. */
1405 			config_sec_spawnflags(load_result, px_sa, new_task);
1406 			/* Clear we were, clear we stay. */
1407 			return 0;
1408 		}
1409 #endif /* DEVELOPMENT || DEBUG */
1410 
1411 		/* Do we have a request to explicitly enable? */
1412 		if ((px_sa->psa_sec_flags & POSIX_SPAWN_SECFLAG_EXPLICIT_ENABLE) != 0) {
1413 			EXEC_LOG("Task is explicitly enabled via posix_spawn flags\n");
1414 			task_set_sec(new_task);
1415 			config_sec_spawnflags(load_result, px_sa, new_task);
1416 			return 0;
1417 		}
1418 
1419 #if HAS_MTE
1420 		/* Do we have a request to enforce that the target is properly entitled? */
1421 		if ((px_sa->psa_sec_flags & POSIX_SPAWN_SECFLAG_EXPLICIT_REQUIRE_ENABLE) != 0) {
1422 			if (!load_result->hardened_process_version) {
1423 				EXEC_LOG("Caller requested the explicit presence of the hardened-process entitlement"
1424 				    " which the binary doesn't have\n");
1425 				return EINVAL;
1426 			}
1427 			/* FALLTHROUGH to entitlement evaluation */
1428 		}
1429 #endif /* HAS_MTE */
1430 	}
1431 
1432 #if HAS_MTE
1433 
1434 #if DEVELOPMENT || DEBUG
1435 	/* Runtime options solely affect entitlement-driven choices. */
1436 	if (!mte_user_enabled()) {
1437 		/* Clear we were, clear we stay. */
1438 		return 0;
1439 	}
1440 #endif /* DEVELOPMENT || DEBUG */
1441 
1442 	struct cs_blob* cs_blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
1443 
1444 	switch (imgact_setup_has_checked_allocations_entitlement(imgp, load_result, new_task, cs_blob)) {
1445 	case EXEC_SECURITY_INVALID_CONFIG:
1446 		EXEC_LOG("Invalid configuration detected\n");
1447 		return EINVAL;
1448 	case EXEC_SECURITY_ENTITLED:
1449 		EXEC_LOG("Task is explicitly configured via entitlements\n");
1450 		task_set_sec(new_task);
1451 		return config_checked_allocations_entitlements(imgp, load_result, new_task, cs_blob,
1452 		           new_proc);
1453 	case EXEC_SECURITY_NOT_ENTITLED:
1454 #if DEVELOPMENT || DEBUG
1455 		/* Last chance: everything 1p is force-enabled. */
1456 		if (mte_force_all_enabled() && load_result->platform_binary) {
1457 			EXEC_LOG("Task is explicitly configured via enable-all boot-arg\n");
1458 			task_set_sec(new_task);
1459 		}
1460 #endif /* DEVELOPMENT || DEBUG */
1461 		return 0;
1462 	default:
1463 		panic("Invalid return value from entitlement evaluation");
1464 	}
1465 #endif /* HAS_MTE */
1466 
1467 	return 0;
1468 }
1469 
1470 /*
1471  * MTE/Checked-allocation configuration.
1472  *
1473  * There are three configuration vectors: inheritance, posix_spawn flags and entitlements.
1474  * Each of the functions below covers one configuration vector.
1475  *
1476  * Configuration vectors are designed to be exclusive when it comes to define how the
1477  * feature will behave. This means that if configurations happens through inheritance,
1478  * it will trump any posix_spawn flag or entitlement and if it happens through
1479  * posix_spawn flag, it will trump entitlements.
1480  *
1481  * Inheritance is provided as a dev feature and needs to be explicitly "enabled" via posix_spawn.
1482  * Just like posix_spawn, it's not allowed to downgrade MTE state.
1483  *
1484  * While there are several posix_spawn flags, the majority of them is again only for
1485  * DEVELOPMENT || DEBUG. Only flags that do not _decrease_ the security posture of the
1486  * target are supported in production (essentially, only flags that _enable_ features).
1487  * posix_spawn flags are also the only way to control the emulation of MTE via the
1488  * readiness tool based on Rosetta.
1489  *
1490  * Entitlements are the expected and preferred way to configure MTE/checked-allocations
1491  * for the system. They are not supported for the Rosetta based emulation.
1492  */
1493 
1494 #if DEVELOPMENT || DEBUG
1495 static inline void
config_sec_inheritance(task_t current,task_t new_task)1496 config_sec_inheritance(task_t current, task_t new_task)
1497 {
1498 	/* Configure the target task based on current task */
1499 	if (task_has_sec_never_check(current)) {
1500 		task_set_sec_never_check(new_task);
1501 		vm_map_set_sec_disabled(get_task_map(new_task));
1502 	}
1503 
1504 	if (task_has_sec_user_data(current)) {
1505 		task_set_sec_user_data(new_task);
1506 	}
1507 
1508 	/* Allow soft-mode to propagate for internal testing */
1509 	if (task_has_sec_soft_mode(current)) {
1510 		task_set_sec_soft_mode(new_task);
1511 	}
1512 }
1513 
1514 #endif /* DEVELOPMENT || DEBUG */
1515 
1516 static inline void
config_sec_spawnflags(load_result_t * load_result,struct _posix_spawnattr * px_sa,task_t new_task)1517 config_sec_spawnflags(load_result_t *load_result,
1518     struct _posix_spawnattr *px_sa, task_t new_task)
1519 {
1520 	/* We cannot be here if there were no posix_spawn attributes */
1521 	assert(px_sa);
1522 
1523 	/*
1524 	 * Most configurations are not available on RELEASE, but we need to
1525 	 * allow inheritance for Xcode debugging workflows.
1526 	 */
1527 	if ((px_sa->psa_sec_flags & POSIX_SPAWN_SECFLAG_EXPLICIT_ENABLE_INHERIT) != 0) {
1528 		EXEC_LOG("Task explicitly enables inheritance via posix_spawn flags\n");
1529 		task_set_sec_inherit(new_task);
1530 	}
1531 
1532 	/*
1533 	 * On both RELEASE and DEVELOPMENT, we allow preflighting MTE through
1534 	 * posix spawn flags: unlike POSIX_SPAWN_SECFLAG_EXPLICIT_CHECK_BYPASS,
1535 	 * with POSIX_SPAWN_SECFLAG_EXPLICIT_PREFLIGHT we only allow turning
1536 	 * on soft mode if the process is not a hardened process.
1537 	 */
1538 	if ((px_sa->psa_sec_flags & POSIX_SPAWN_SECFLAG_EXPLICIT_PREFLIGHT) != 0) {
1539 		if (!load_result->hardened_process_version) {
1540 			EXEC_LOG("Task explicitly enables soft-mode preflight via posix_spawn flags\n");
1541 			task_set_sec_soft_mode(new_task);
1542 		}
1543 	}
1544 
1545 #if DEVELOPMENT || DEBUG
1546 	if ((px_sa->psa_sec_flags & POSIX_SPAWN_SECFLAG_EXPLICIT_ENABLE_PURE_DATA) != 0) {
1547 		EXEC_LOG("Task explicitly enables userspace coverage via posix_spawn flags\n");
1548 		task_set_sec_user_data(new_task);
1549 	}
1550 
1551 	/* Allow testing of soft-mode via posix_spawn */
1552 	if ((px_sa->psa_sec_flags & POSIX_SPAWN_SECFLAG_EXPLICIT_CHECK_BYPASS) != 0) {
1553 		EXEC_LOG("Task explicitly enables soft-mode via posix_spawn flags\n");
1554 		task_set_sec_soft_mode(new_task);
1555 	}
1556 
1557 	if ((px_sa->psa_sec_flags & POSIX_SPAWN_SECFLAG_EXPLICIT_NEVER_CHECK_ENABLE) != 0) {
1558 		task_set_sec_never_check(new_task);
1559 		vm_map_set_sec_disabled(get_task_map(new_task));
1560 	}
1561 #endif /* DEVELOPMENT || DEBUG */
1562 }
1563 
1564 #if HAS_MTE
1565 
1566 static inline errno_t
config_checked_allocations_entitlements(struct image_params * imgp,load_result_t * load_result,task_t new_task,__unused struct cs_blob * cs_blob,__unused proc_t new_proc)1567 config_checked_allocations_entitlements(struct image_params *imgp, load_result_t *load_result,
1568     task_t new_task, __unused struct cs_blob *cs_blob, __unused proc_t new_proc)
1569 {
1570 	/* Determine whether we should enable pure-data allocations. */
1571 	exec_security_err_t ret = exec_check_security_entitlement(imgp,
1572 	    CHECKED_ALLOCATIONS_PURE_DATA);
1573 	assert(ret == EXEC_SECURITY_ENTITLED || ret == EXEC_SECURITY_NOT_ENTITLED);
1574 
1575 	if (ret == EXEC_SECURITY_ENTITLED) {
1576 		task_set_sec_user_data(new_task);
1577 		EXEC_LOG("Enabling user data tagging due to entitlement\n");
1578 	}
1579 
1580 
1581 	/*
1582 	 * Check whether we need to restrict receiving aliases to MTE memory (which are, by policy,
1583 	 * untagged) from other actors.
1584 	 */
1585 	ret = exec_check_security_entitlement(imgp, CHECKED_ALLOCATIONS_NO_TAGGED_RECEIVE);
1586 	assert(ret == EXEC_SECURITY_ENTITLED || ret == EXEC_SECURITY_NOT_ENTITLED);
1587 
1588 	if (ret == EXEC_SECURITY_ENTITLED) {
1589 		EXEC_LOG("Restricting receiving aliases to tagged memory due to entitlement\n");
1590 		task_set_sec_restrict_receiving_aliases_to_tagged_memory(new_task);
1591 	}
1592 
1593 
1594 	ret = exec_check_security_entitlement(imgp, CHECKED_ALLOCATIONS_SOFT_MODE);
1595 	assert(ret == EXEC_SECURITY_ENTITLED || ret == EXEC_SECURITY_NOT_ENTITLED);
1596 
1597 	/*
1598 	 * All 1p processes run in hard-mode in lockdown mode, regardless of their
1599 	 * entitlement configuration.
1600 	 */
1601 	if (load_result->platform_binary && get_lockdown_mode_state() != 0) {
1602 		ret = EXEC_SECURITY_NOT_ENTITLED;
1603 	}
1604 
1605 	/*
1606 	 * Force enable soft-mode for anything that is not a platform binary.
1607 	 */
1608 	if (ret == EXEC_SECURITY_ENTITLED || !load_result->platform_binary) {
1609 		EXEC_LOG("Enabling soft-mode from entitlement\n");
1610 		task_set_sec_soft_mode(new_task);
1611 	}
1612 
1613 	return EXEC_SECURITY_NOT_ENTITLED;
1614 }
1615 
1616 #endif /* HAS_MTE */
1617 #endif /* HAS_MTE || HAS_MTE_EMULATION_SHIMS */
1618 
1619 static inline errno_t
imgact_setup_guard_objects(struct image_params * imgp,load_result_t * load_result,task_t task)1620 imgact_setup_guard_objects(struct image_params *imgp, load_result_t *load_result, task_t task)
1621 {
1622 	exec_security_err_t ret = exec_check_security_entitlement(imgp, NO_GUARD_OBJECTS);
1623 	if (ret == EXEC_SECURITY_NOT_ENTITLED &&
1624 	    load_result->hardened_process_version >= HARDENED_PROCESS_VERSION_TWO) {
1625 		/* apply guard objects entitlement if hardened-process and not disabled */
1626 		task_set_guard_objects(task);
1627 		return 0;
1628 	}
1629 
1630 	task_clear_guard_objects(task);
1631 
1632 	if (ret == EXEC_SECURITY_INVALID_CONFIG) {
1633 		return EINVAL;
1634 	}
1635 
1636 	return 0;
1637 }
1638 
1639 /*
1640  * This routine configures the various runtime mitigations we can apply to a process
1641  * during image activation. This occurs before `imgact_setup_runtime_mitigations`
1642  *
1643  * Returns true on success, false on failure. Failure will be fatal in exec_mach_imgact().
1644  */
1645 static inline errno_t
imgact_setup_runtime_mitigations(struct image_params * imgp,__unused load_result_t * load_result,__unused task_t old_task,task_t new_task,__unused vm_map_t map,__unused proc_t proc)1646 imgact_setup_runtime_mitigations(struct image_params *imgp, __unused load_result_t *load_result,
1647     __unused task_t old_task, task_t new_task, __unused vm_map_t map, __unused proc_t proc)
1648 {
1649 	/* Set hardened process version */
1650 	task_set_hardened_process_version(new_task, load_result->hardened_process_version);
1651 
1652 	/*
1653 	 * It's safe to check entitlements anytime after `load_machfile` if you check
1654 	 * based on the vnode in imgp. We must perform this entitlement check
1655 	 * before we start using load_result->hardened_browser further down
1656 	 */
1657 	load_result->hardened_browser = 0;
1658 	encode_HR_entitlement(kCSWebBrowserHostEntitlement, BrowserHostEntitlementMask, imgp, load_result);
1659 	encode_HR_entitlement(kCSWebBrowserGPUEntitlement, BrowserGPUEntitlementMask, imgp, load_result);
1660 	encode_HR_entitlement(kCSWebBrowserNetworkEntitlement, BrowserNetworkEntitlementMask, imgp, load_result);
1661 	encode_HR_entitlement(kCSWebBrowserWebContentEntitlement, BrowserWebContentEntitlementMask, imgp, load_result);
1662 
1663 	if (load_result->hardened_browser) {
1664 		task_set_platform_restrictions_version(new_task, 1);
1665 	}
1666 
1667 	errno_t retval = 0;
1668 
1669 	/*
1670 	 * Hardened-heap enables a set of extra security features in our system memory allocator.
1671 	 */
1672 	if ((retval = imgact_setup_hardened_heap(imgp, new_task)) != 0) {
1673 		EXEC_LOG("Invalid configuration detected for hardened-heap");
1674 		return retval;
1675 	}
1676 
1677 #if HAS_MTE || HAS_MTE_EMULATION_SHIMS
1678 	/*
1679 	 * Sec-shims a.k.a. checked-allocations a.k.a. MTE (due to several hoops around secrecy)
1680 	 * control whether the target process system allocators leverage MTE or not to provide
1681 	 * further security mitigations.
1682 	 */
1683 	if ((retval = imgact_setup_sec(imgp, load_result, old_task, new_task, map, proc)) != 0) {
1684 		EXEC_LOG("Invalid configuration detected for the security shim");
1685 		return retval;
1686 	}
1687 #endif /* HAS_MTE || HAS_MTE_EMULATION_SHIMS */
1688 
1689 	/*
1690 	 * No-guard-objects disables guards for process deallocated allocations or VM.
1691 	 */
1692 	if ((retval = imgact_setup_guard_objects(imgp, load_result, new_task)) != 0) {
1693 		EXEC_LOG("Invalid configuration detected for no-guard-objects");
1694 		return retval;
1695 	}
1696 
1697 	return retval;
1698 }
1699 
1700 uint32_t
rsr_get_version(void)1701 rsr_get_version(void)
1702 {
1703 	return os_atomic_load(&rsr_current_version, relaxed);
1704 }
1705 
1706 void
rsr_bump_version(void)1707 rsr_bump_version(void)
1708 {
1709 	os_atomic_inc(&rsr_current_version, relaxed);
1710 }
1711 
1712 #if XNU_TARGET_OS_OSX
1713 static int
1714 rsr_version_sysctl SYSCTL_HANDLER_ARGS
1715 {
1716 #pragma unused(arg1, arg2, oidp)
1717 	int value = rsr_get_version();
1718 	int error = SYSCTL_OUT(req, &value, sizeof(int));
1719 	if (error) {
1720 		return error;
1721 	}
1722 
1723 	if (!req->newptr) {
1724 		return 0;
1725 	}
1726 
1727 	error = SYSCTL_IN(req, &value, sizeof(int));
1728 	if (error) {
1729 		return error;
1730 	}
1731 	if (value != 0) {
1732 		rsr_bump_version();
1733 	}
1734 	return 0;
1735 }
1736 
1737 
1738 SYSCTL_PROC(_vm, OID_AUTO, shared_region_control,
1739     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
1740     0, 0, rsr_version_sysctl, "I", "");
1741 #endif /* XNU_TARGET_OS_OSX */
1742 
1743 /*
1744  * exec_mach_imgact
1745  *
1746  * Image activator for mach-o 1.0 binaries.
1747  *
1748  * Parameters;	struct image_params *	image parameter block
1749  *
1750  * Returns:	-1			not a fat binary (keep looking)
1751  *		-2			Success: encapsulated binary: reread
1752  *		>0			Failure: error number
1753  *		EBADARCH		Mach-o binary, but with an unrecognized
1754  *					architecture
1755  *		ENOMEM			No memory for child process after -
1756  *					can only happen after vfork()
1757  *
1758  * Important:	This image activator is NOT byte order neutral.
1759  *
1760  * Note:	A return value other than -1 indicates subsequent image
1761  *		activators should not be given the opportunity to attempt
1762  *		to activate the image.
1763  */
1764 static int
exec_mach_imgact(struct image_params * imgp)1765 exec_mach_imgact(struct image_params *imgp)
1766 {
1767 	struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1768 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
1769 	int                     error = 0;
1770 	task_t                  task;
1771 	task_t                  new_task = NULL;    /* protected by vfexec */
1772 	thread_t                thread;
1773 	struct uthread          *uthread;
1774 	vm_map_switch_context_t switch_ctx;
1775 	vm_map_t old_map = VM_MAP_NULL;
1776 	vm_map_t map = VM_MAP_NULL;
1777 	load_return_t           lret;
1778 	load_result_t           load_result = {};
1779 	struct _posix_spawnattr *psa = NULL;
1780 	int                     spawn = (imgp->ip_flags & IMGPF_SPAWN);
1781 	const int               vfexec = 0;
1782 	int                     exec = (imgp->ip_flags & IMGPF_EXEC);
1783 	os_reason_t             exec_failure_reason = OS_REASON_NULL;
1784 	boolean_t               reslide = FALSE;
1785 	char *                  userspace_coredump_name = NULL;
1786 
1787 	/*
1788 	 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1789 	 * is a reserved field on the end, so for the most part, we can
1790 	 * treat them as if they were identical. Reverse-endian Mach-O
1791 	 * binaries are recognized but not compatible.
1792 	 */
1793 	if ((mach_header->magic == MH_CIGAM) ||
1794 	    (mach_header->magic == MH_CIGAM_64)) {
1795 		error = EBADARCH;
1796 		goto bad;
1797 	}
1798 
1799 	if ((mach_header->magic != MH_MAGIC) &&
1800 	    (mach_header->magic != MH_MAGIC_64)) {
1801 		error = -1;
1802 		goto bad;
1803 	}
1804 
1805 	if (mach_header->filetype != MH_EXECUTE) {
1806 		error = -1;
1807 		goto bad;
1808 	}
1809 
1810 	if (imgp->ip_origcputype != 0) {
1811 		/* Fat header previously had an idea about this thin file */
1812 		if (imgp->ip_origcputype != mach_header->cputype ||
1813 		    imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1814 			error = EBADARCH;
1815 			goto bad;
1816 		}
1817 	} else {
1818 		imgp->ip_origcputype = mach_header->cputype;
1819 		imgp->ip_origcpusubtype = mach_header->cpusubtype;
1820 	}
1821 
1822 	task = current_task();
1823 	thread = current_thread();
1824 	uthread = get_bsdthread_info(thread);
1825 
1826 	if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1827 		imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1828 	}
1829 
1830 
1831 	/* If posix_spawn binprefs exist, respect those prefs. */
1832 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1833 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
1834 		int pr = 0;
1835 		for (pr = 0; pr < NBINPREFS; pr++) {
1836 			cpu_type_t pref = psa->psa_binprefs[pr];
1837 			cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1838 
1839 			if (pref == 0) {
1840 				/* No suitable arch in the pref list */
1841 				error = EBADARCH;
1842 				goto bad;
1843 			}
1844 
1845 			if (pref == CPU_TYPE_ANY) {
1846 				/* Jump to regular grading */
1847 				goto grade;
1848 			}
1849 
1850 			if (binary_match(CPU_ARCH_MASK, pref, subpref,
1851 			    imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1852 				goto grade;
1853 			}
1854 		}
1855 		error = EBADARCH;
1856 		goto bad;
1857 	}
1858 grade:
1859 	if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1860 	    imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1861 		error = EBADARCH;
1862 		goto bad;
1863 	}
1864 
1865 	if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1866 	    imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1867 #if __x86_64__
1868 		const char *excpath;
1869 		error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1870 		os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1871 #endif
1872 		error = EBADARCH;
1873 		goto bad;
1874 	}
1875 
1876 #if defined(HAS_APPLE_PAC)
1877 	assert(mach_header->cputype == CPU_TYPE_ARM64
1878 	    );
1879 
1880 	if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1881 	    arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1882 	    ) {
1883 		imgp->ip_flags &= ~IMGPF_NOJOP;
1884 	} else {
1885 		imgp->ip_flags |= IMGPF_NOJOP;
1886 	}
1887 #endif
1888 
1889 	/* Copy in arguments/environment from the old process */
1890 	error = exec_extract_strings(imgp);
1891 	if (error) {
1892 		goto bad;
1893 	}
1894 
1895 	AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1896 	    imgp->ip_endargv - imgp->ip_startargv);
1897 	AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1898 	    imgp->ip_endenvv - imgp->ip_endargv);
1899 
1900 	/* reset local idea of thread, uthread, task */
1901 	thread = imgp->ip_new_thread;
1902 	uthread = get_bsdthread_info(thread);
1903 	task = new_task = get_threadtask(thread);
1904 
1905 	/*
1906 	 *	Load the Mach-O file.
1907 	 *
1908 	 * NOTE: An error after this point  indicates we have potentially
1909 	 * destroyed or overwritten some process state while attempting an
1910 	 * execve() following a vfork(), which is an unrecoverable condition.
1911 	 * We send the new process an immediate SIGKILL to avoid it executing
1912 	 * any instructions in the mutated address space. For true spawns,
1913 	 * this is not the case, and "too late" is still not too late to
1914 	 * return an error code to the parent process.
1915 	 */
1916 
1917 	/*
1918 	 * Actually load the image file we previously decided to load.
1919 	 */
1920 	lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1921 	if (lret != LOAD_SUCCESS) {
1922 		error = load_return_to_errno(lret);
1923 
1924 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1925 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1926 		if (lret == LOAD_BADMACHO_UPX) {
1927 			set_proc_name(imgp, p);
1928 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1929 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1930 		} else {
1931 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1932 
1933 			if (bootarg_execfailurereports) {
1934 				set_proc_name(imgp, p);
1935 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1936 			}
1937 		}
1938 
1939 		exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1940 
1941 		goto badtoolate;
1942 	}
1943 
1944 	assert(imgp->ip_free_map == NULL);
1945 
1946 	/*
1947 	 * ERROR RECOVERY
1948 	 *
1949 	 * load_machfile() returned the new VM map ("map") but we haven't
1950 	 * committed to it yet.
1951 	 * Any error path between here and the point where we commit to using
1952 	 * the new "map" (with swap_task_map()) should deallocate "map".
1953 	 */
1954 
1955 #ifndef KASAN
1956 	/*
1957 	 * Security: zone sanity checks on fresh boot or initproc re-exec.
1958 	 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1959 	 * which means here is the earliest point we can assert on empty service port label zone,
1960 	 * after load_machfile() above terminates old launchd's IPC space.
1961 	 *
1962 	 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1963 	 * under quarantine.
1964 	 */
1965 	if (task_pid(task) == 1) {
1966 		zone_userspace_reboot_checks();
1967 	}
1968 #endif
1969 
1970 	proc_lock(p);
1971 	p->p_cputype = imgp->ip_origcputype;
1972 	p->p_cpusubtype = imgp->ip_origcpusubtype;
1973 	proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1974 
1975 	vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1976 	vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1977 	vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1978 
1979 #if XNU_TARGET_OS_OSX
1980 	if (proc_platform(p) == PLATFORM_IOS) {
1981 		assert(vm_map_is_alien(map));
1982 	} else {
1983 		assert(!vm_map_is_alien(map));
1984 	}
1985 #endif /* XNU_TARGET_OS_OSX */
1986 	proc_unlock(p);
1987 
1988 	/*
1989 	 * Setup runtime mitigations.
1990 	 */
1991 	if ((error = imgact_setup_runtime_mitigations(imgp, &load_result, current_task(), new_task, map, p)) != 0) {
1992 		set_proc_name(imgp, p);
1993 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1994 		if (bootarg_execfailurereports) {
1995 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1996 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1997 		}
1998 		/* release new address space since we won't use it */
1999 		imgp->ip_free_map = map;
2000 		map = VM_MAP_NULL;
2001 		goto badtoolate;
2002 	}
2003 
2004 	/*
2005 	 * Set code-signing flags if this binary is signed, or if parent has
2006 	 * requested them on exec.
2007 	 */
2008 	if (load_result.csflags & CS_VALID) {
2009 		imgp->ip_csflags |= load_result.csflags &
2010 		    (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
2011 		    CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
2012 		    CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
2013 		    CS_ENTITLEMENT_FLAGS |
2014 		    CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
2015 	} else {
2016 		imgp->ip_csflags &= ~CS_VALID;
2017 	}
2018 
2019 	if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
2020 		imgp->ip_csflags |= CS_HARD;
2021 	}
2022 	if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
2023 		imgp->ip_csflags |= CS_KILL;
2024 	}
2025 	if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
2026 		imgp->ip_csflags |= CS_ENFORCEMENT;
2027 	}
2028 	if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
2029 		if (proc_getcsflags(p) & CS_INSTALLER) {
2030 			imgp->ip_csflags |= CS_INSTALLER;
2031 		}
2032 		if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
2033 			imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
2034 		}
2035 		if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
2036 			imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
2037 		}
2038 	}
2039 
2040 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
2041 	/*
2042 	 * ptrauth version 0 is a preview ABI.  Developers can opt into running
2043 	 * their own arm64e binaries for local testing, with the understanding
2044 	 * that future OSes may break ABI.
2045 	 */
2046 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
2047 	    CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
2048 	    !load_result.platform_binary &&
2049 	    !bootarg_arm64e_preview_abi) {
2050 		static bool logged_once = false;
2051 		set_proc_name(imgp, p);
2052 
2053 		printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
2054 		if (!os_atomic_xchg(&logged_once, true, relaxed)) {
2055 			printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
2056 		}
2057 
2058 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
2059 		if (bootarg_execfailurereports) {
2060 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2061 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
2062 		}
2063 
2064 		/* release new address space since we won't use it */
2065 		imgp->ip_free_map = map;
2066 		map = VM_MAP_NULL;
2067 		goto badtoolate;
2068 	}
2069 
2070 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
2071 	    imgp->ip_origcputype == CPU_TYPE_ARM64 &&
2072 	    load_result.platform_binary &&
2073 	    (imgp->ip_flags & IMGPF_DRIVER) != 0) {
2074 		set_proc_name(imgp, p);
2075 		printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
2076 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
2077 		if (bootarg_execfailurereports) {
2078 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2079 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
2080 		}
2081 
2082 		/* release new address space since we won't use it */
2083 		imgp->ip_free_map = map;
2084 		map = VM_MAP_NULL;
2085 		goto badtoolate;
2086 	}
2087 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
2088 
2089 
2090 
2091 	/*
2092 	 * Set up the shared cache region in the new process.
2093 	 *
2094 	 * Normally there is a single shared region per architecture.
2095 	 * However on systems with Pointer Authentication, we can create
2096 	 * multiple shared caches with the amount of sharing determined
2097 	 * by team-id or entitlement. Inherited shared region IDs are used
2098 	 * for system processes that need to match and be able to inspect
2099 	 * a pre-existing task.
2100 	 */
2101 	int cpu_subtype = 0;     /* all cpu_subtypes use the same shared region */
2102 #if __has_feature(ptrauth_calls)
2103 	char *shared_region_id = NULL;
2104 	size_t len;
2105 	char *base;
2106 	const char *cbase;
2107 #define HARDENED_RUNTIME_CONTENT_ID "C-"
2108 #define TEAM_ID_PREFIX "T-"
2109 #define ENTITLE_PREFIX "E-"
2110 #define SR_PREFIX_LEN  2
2111 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
2112 
2113 	if (cpu_type() == CPU_TYPE_ARM64 &&
2114 	    arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
2115 	    (imgp->ip_flags & IMGPF_NOJOP) == 0) {
2116 		assertf(p->p_cputype == CPU_TYPE_ARM64,
2117 		    "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
2118 		    p, cpu_type(), p->p_cputype, p->p_cpusubtype);
2119 
2120 		/*
2121 		 * arm64e uses pointer authentication, so request a separate
2122 		 * shared region for this CPU subtype.
2123 		 */
2124 		cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
2125 
2126 		/*
2127 		 * Determine which shared cache to select based on being told,
2128 		 * matching a team-id or matching an entitlement.
2129 		 */
2130 		if (load_result.hardened_browser & BrowserWebContentEntitlementMask) {
2131 			len = sizeof(HARDENED_RUNTIME_CONTENT_ID);
2132 			shared_region_id = kalloc_data(len, Z_WAITOK | Z_NOFAIL);
2133 			strlcpy(shared_region_id, HARDENED_RUNTIME_CONTENT_ID, len);
2134 		} else if (imgp->ip_inherited_shared_region_id) {
2135 			len = strlen(imgp->ip_inherited_shared_region_id);
2136 			shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
2137 			memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
2138 		} else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
2139 			len = strlen(cbase);
2140 			if (vm_shared_region_per_team_id) {
2141 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
2142 				    Z_WAITOK | Z_NOFAIL);
2143 				memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
2144 				memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
2145 			}
2146 		} else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
2147 		    (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
2148 			len = strlen(base);
2149 			if (vm_shared_region_by_entitlement) {
2150 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
2151 				    Z_WAITOK | Z_NOFAIL);
2152 				memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
2153 				memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
2154 			}
2155 			/* Discard the copy of the entitlement */
2156 			kfree_data(base, len + 1);
2157 		}
2158 	}
2159 
2160 	if (imgp->ip_flags & IMGPF_RESLIDE) {
2161 		reslide = TRUE;
2162 	}
2163 
2164 	/* use "" as the default shared_region_id */
2165 	if (shared_region_id == NULL) {
2166 		shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2167 	}
2168 
2169 	/* ensure there's a unique pointer signing key for this shared_region_id */
2170 	shared_region_key_alloc(shared_region_id,
2171 	    imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
2172 	task_set_shared_region_id(task, shared_region_id);
2173 	shared_region_id = NULL;
2174 #endif /* __has_feature(ptrauth_calls) */
2175 
2176 #if CONFIG_ROSETTA
2177 	if (imgp->ip_flags & IMGPF_ROSETTA) {
2178 		OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
2179 	} else if (p->p_flag & P_TRANSLATED) {
2180 		OSBitAndAtomic(~P_TRANSLATED, &p->p_flag);
2181 	}
2182 #endif
2183 
2184 	int cputype = cpu_type();
2185 
2186 	uint32_t rsr_version = 0;
2187 #if XNU_TARGET_OS_OSX
2188 	if (vnode_is_rsr(imgp->ip_vp)) {
2189 		rsr_version = rsr_get_version();
2190 		os_atomic_or(&p->p_ladvflag, P_RSR, relaxed);
2191 		os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_ALTLINK, relaxed);
2192 	}
2193 #endif /* XNU_TARGET_OS_OSX */
2194 
2195 	error = vm_map_exec(map, task, load_result.is_64bit_addr,
2196 	    (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide,
2197 	    (imgp->ip_flags & IMGPF_DRIVER) != 0,
2198 	    rsr_version);
2199 
2200 	if (error) {
2201 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2202 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAP_EXEC_FAILURE, 0, 0);
2203 
2204 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAP_EXEC_FAILURE);
2205 		if (bootarg_execfailurereports) {
2206 			set_proc_name(imgp, p);
2207 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2208 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
2209 		}
2210 		/* release new address space since we won't use it */
2211 		imgp->ip_free_map = map;
2212 		map = VM_MAP_NULL;
2213 		goto badtoolate;
2214 	}
2215 
2216 	/*
2217 	 * Close file descriptors which specify close-on-exec.
2218 	 */
2219 	fdt_exec(p, vfs_context_ucred(imgp->ip_vfs_context),
2220 	    psa != NULL ? psa->psa_flags : 0, imgp->ip_new_thread, exec);
2221 
2222 	/*
2223 	 * deal with set[ug]id.
2224 	 */
2225 	error = exec_handle_sugid(imgp);
2226 	if (error) {
2227 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2228 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
2229 
2230 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
2231 		if (bootarg_execfailurereports) {
2232 			set_proc_name(imgp, p);
2233 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2234 		}
2235 
2236 		/* release new address space since we won't use it */
2237 		imgp->ip_free_map = map;
2238 		map = VM_MAP_NULL;
2239 		goto badtoolate;
2240 	}
2241 
2242 	/*
2243 	 * Commit to new map.
2244 	 *
2245 	 * Swap the new map for the old for target task, which consumes
2246 	 * our new map reference but each leaves us responsible for the
2247 	 * old_map reference.  That lets us get off the pmap associated
2248 	 * with it, and then we can release it.
2249 	 *
2250 	 * The map needs to be set on the target task which is different
2251 	 * than current task, thus swap_task_map is used instead of
2252 	 * vm_map_switch.
2253 	 */
2254 	old_map = swap_task_map(task, thread, map);
2255 #if MACH_ASSERT
2256 	/*
2257 	 * Reset the pmap's process info to prevent ledger checks
2258 	 * which might fail due to the ledgers being shared between
2259 	 * the old and new pmaps.
2260 	 */
2261 	vm_map_pmap_set_process(old_map, -1, "<old_map>");
2262 #endif /* MACH_ASSERT */
2263 	imgp->ip_free_map = old_map;
2264 	old_map = NULL;
2265 
2266 	lret = activate_exec_state(task, p, thread, &load_result);
2267 	if (lret != KERN_SUCCESS) {
2268 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2269 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
2270 
2271 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
2272 		if (bootarg_execfailurereports) {
2273 			set_proc_name(imgp, p);
2274 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2275 		}
2276 
2277 		goto badtoolate;
2278 	}
2279 
2280 	/*
2281 	 * deal with voucher on exec-calling thread.
2282 	 */
2283 	if (imgp->ip_new_thread == NULL) {
2284 		thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
2285 	}
2286 
2287 	/* Make sure we won't interrupt ourself signalling a partial process */
2288 	if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
2289 		psignal(p, SIGTRAP);
2290 	}
2291 
2292 	if (load_result.unixproc &&
2293 	    create_unix_stack(get_task_map(task),
2294 	    &load_result,
2295 	    p) != KERN_SUCCESS) {
2296 		error = load_return_to_errno(LOAD_NOSPACE);
2297 
2298 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2299 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
2300 
2301 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
2302 		if (bootarg_execfailurereports) {
2303 			set_proc_name(imgp, p);
2304 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2305 		}
2306 
2307 		goto badtoolate;
2308 	}
2309 
2310 	/*
2311 	 * The load result will have already been munged by AMFI to include the
2312 	 * platform binary flag if boot-args dictated it (AMFI will mark anything
2313 	 * that doesn't go through the upcall path as a platform binary if its
2314 	 * enforcement is disabled).
2315 	 */
2316 	if (load_result.platform_binary) {
2317 		if (cs_debug) {
2318 			printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
2319 		}
2320 
2321 		/*
2322 		 * We must use 'task' here because the proc's task has not yet been
2323 		 * switched to the new one.
2324 		 */
2325 		task_set_platform_binary(task, TRUE);
2326 	} else {
2327 		if (cs_debug) {
2328 			printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
2329 		}
2330 
2331 		task_set_platform_binary(task, FALSE);
2332 	}
2333 
2334 #if XNU_TARGET_OS_OSX
2335 	/* Disable mach hardening for all 1P tasks which load 3P plugins */
2336 	if (imgp->ip_flags & IMGPF_3P_PLUGINS) {
2337 		if (cs_debug) {
2338 			printf("Disabling some mach hardening on task due to 3P plugins: pid = %d\n", proc_getpid(p));
2339 		}
2340 		task_disable_mach_hardening(task);
2341 	}
2342 #if DEVELOPMENT || DEBUG
2343 	/* Disable mach hardening for all tasks if amfi_get_out_of_my_way is set.
2344 	 * Customers will have to turn SIP off to use this boot-arg, and so this is
2345 	 * only needed internally since we disable this feature when SIP is off. */
2346 	if (AMFI_bootarg_disable_mach_hardening) {
2347 		if (cs_debug) {
2348 			printf("Disabling some mach hardening on task due to AMFI boot-args: pid = %d\n", proc_getpid(p));
2349 		}
2350 		task_disable_mach_hardening(task);
2351 	}
2352 #endif /* DEVELOPMENT || DEBUG */
2353 #endif /* XNU_TARGET_OS_OSX */
2354 
2355 	error = exec_add_apple_strings(imgp, &load_result, task);     /* copies out main thread port */
2356 
2357 	if (error) {
2358 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2359 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
2360 
2361 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
2362 		if (bootarg_execfailurereports) {
2363 			set_proc_name(imgp, p);
2364 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2365 		}
2366 		goto badtoolate;
2367 	}
2368 
2369 	/* Switch to target task's map to copy out strings */
2370 	switch_ctx = vm_map_switch_to(get_task_map(task));
2371 
2372 	if (load_result.unixproc) {
2373 		user_addr_t     ap;
2374 
2375 		/*
2376 		 * Copy the strings area out into the new process address
2377 		 * space.
2378 		 */
2379 		ap = p->user_stack;
2380 		error = exec_copyout_strings(imgp, &ap);
2381 		if (error) {
2382 			vm_map_switch_back(switch_ctx);
2383 
2384 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2385 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
2386 
2387 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
2388 			if (bootarg_execfailurereports) {
2389 				set_proc_name(imgp, p);
2390 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2391 			}
2392 			goto badtoolate;
2393 		}
2394 		/* Set the stack */
2395 		thread_setuserstack(thread, ap);
2396 	}
2397 
2398 	if (load_result.dynlinker || load_result.is_rosetta) {
2399 		user_addr_t        ap;
2400 		int                     new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
2401 
2402 		/* Adjust the stack */
2403 		ap = thread_adjuserstack(thread, -new_ptr_size);
2404 		error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
2405 
2406 		if (error) {
2407 			vm_map_switch_back(switch_ctx);
2408 
2409 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2410 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
2411 
2412 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
2413 			if (bootarg_execfailurereports) {
2414 				set_proc_name(imgp, p);
2415 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2416 			}
2417 			goto badtoolate;
2418 		}
2419 		error = task_set_dyld_info(task, load_result.all_image_info_addr,
2420 		    load_result.all_image_info_size, false);
2421 		if (error) {
2422 			vm_map_switch_back(switch_ctx);
2423 
2424 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2425 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
2426 
2427 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
2428 			if (bootarg_execfailurereports) {
2429 				set_proc_name(imgp, p);
2430 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2431 			}
2432 			error = EINVAL;
2433 			goto badtoolate;
2434 		}
2435 	} else {
2436 		/*
2437 		 * No dyld or rosetta loaded, set the TF_DYLD_ALL_IMAGE_FINAL bit on task.
2438 		 */
2439 		error = task_set_dyld_info(task, MACH_VM_MIN_ADDRESS,
2440 		    0, true);
2441 		if (error) {
2442 			vm_map_switch_back(switch_ctx);
2443 
2444 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2445 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
2446 
2447 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
2448 			if (bootarg_execfailurereports) {
2449 				set_proc_name(imgp, p);
2450 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2451 			}
2452 			error = EINVAL;
2453 			goto badtoolate;
2454 		}
2455 	}
2456 
2457 #if CONFIG_ROSETTA
2458 	if (load_result.is_rosetta) {
2459 		// Add an fd for the executable file for Rosetta's use
2460 		int main_binary_fd;
2461 		struct fileproc *fp;
2462 
2463 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &main_binary_fd);
2464 		if (error) {
2465 			vm_map_switch_back(switch_ctx);
2466 
2467 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2468 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
2469 
2470 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
2471 			if (bootarg_execfailurereports) {
2472 				set_proc_name(imgp, p);
2473 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2474 			}
2475 			goto badtoolate;
2476 		}
2477 
2478 		error = VNOP_OPEN(imgp->ip_vp, FREAD, imgp->ip_vfs_context);
2479 		if (error) {
2480 			vm_map_switch_back(switch_ctx);
2481 
2482 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2483 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
2484 
2485 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
2486 			if (bootarg_execfailurereports) {
2487 				set_proc_name(imgp, p);
2488 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2489 			}
2490 			goto cleanup_rosetta_fp;
2491 		}
2492 
2493 		fp->fp_glob->fg_flag = FREAD;
2494 		fp->fp_glob->fg_ops = &vnops;
2495 		fp_set_data(fp, imgp->ip_vp);
2496 
2497 		proc_fdlock(p);
2498 		procfdtbl_releasefd(p, main_binary_fd, NULL);
2499 		fp_drop(p, main_binary_fd, fp, 1);
2500 		proc_fdunlock(p);
2501 
2502 		vnode_ref(imgp->ip_vp);
2503 
2504 		// Pass the dyld load address, main binary fd, and dyld fd on the stack
2505 		uint64_t ap = thread_adjuserstack(thread, -24);
2506 
2507 		error = copyoutptr((user_addr_t)load_result.dynlinker_fd, ap, 8);
2508 		if (error) {
2509 			vm_map_switch_back(switch_ctx);
2510 
2511 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2512 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
2513 
2514 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
2515 			if (bootarg_execfailurereports) {
2516 				set_proc_name(imgp, p);
2517 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2518 			}
2519 			goto cleanup_rosetta_fp;
2520 		}
2521 
2522 		error = copyoutptr(load_result.dynlinker_mach_header, ap + 8, 8);
2523 		if (error) {
2524 			vm_map_switch_back(switch_ctx);
2525 
2526 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2527 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
2528 
2529 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
2530 			if (bootarg_execfailurereports) {
2531 				set_proc_name(imgp, p);
2532 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2533 			}
2534 			goto cleanup_rosetta_fp;
2535 		}
2536 
2537 		error = copyoutptr((user_addr_t)main_binary_fd, ap + 16, 8);
2538 		if (error) {
2539 			vm_map_switch_back(switch_ctx);
2540 
2541 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2542 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
2543 
2544 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
2545 			if (bootarg_execfailurereports) {
2546 				set_proc_name(imgp, p);
2547 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2548 			}
2549 			goto cleanup_rosetta_fp;
2550 		}
2551 
2552 cleanup_rosetta_fp:
2553 		if (error) {
2554 			fp_free(p, load_result.dynlinker_fd, load_result.dynlinker_fp);
2555 			fp_free(p, main_binary_fd, fp);
2556 			goto badtoolate;
2557 		}
2558 	}
2559 
2560 #endif
2561 
2562 	/* Avoid immediate VM faults back into kernel */
2563 	exec_prefault_data(p, imgp, &load_result);
2564 
2565 	vm_map_switch_back(switch_ctx);
2566 
2567 	/*
2568 	 * Reset signal state.
2569 	 */
2570 	execsigs(p, thread);
2571 
2572 	/*
2573 	 * need to cancel async IO requests that can be cancelled and wait for those
2574 	 * already active.  MAY BLOCK!
2575 	 */
2576 	_aio_exec( p );
2577 
2578 #if SYSV_SHM
2579 	/* FIXME: Till vmspace inherit is fixed: */
2580 	if (!vfexec && p->vm_shm) {
2581 		shmexec(p);
2582 	}
2583 #endif
2584 #if SYSV_SEM
2585 	/* Clean up the semaphores */
2586 	semexit(p);
2587 #endif
2588 
2589 	/*
2590 	 * Remember file name for accounting.
2591 	 */
2592 	p->p_acflag &= ~AFORK;
2593 
2594 	set_proc_name(imgp, p);
2595 
2596 #if CONFIG_SECLUDED_MEMORY
2597 	if (secluded_for_apps &&
2598 	    load_result.platform_binary) {
2599 		if (strncmp(p->p_name,
2600 		    "Camera",
2601 		    sizeof(p->p_name)) == 0) {
2602 			task_set_could_use_secluded_mem(task, TRUE);
2603 		} else {
2604 			task_set_could_use_secluded_mem(task, FALSE);
2605 		}
2606 		if (strncmp(p->p_name,
2607 		    "mediaserverd",
2608 		    sizeof(p->p_name)) == 0) {
2609 			task_set_could_also_use_secluded_mem(task, TRUE);
2610 		}
2611 		if (strncmp(p->p_name,
2612 		    "cameracaptured",
2613 		    sizeof(p->p_name)) == 0) {
2614 			task_set_could_also_use_secluded_mem(task, TRUE);
2615 		}
2616 	}
2617 #endif /* CONFIG_SECLUDED_MEMORY */
2618 
2619 #if __arm64__
2620 	if (load_result.legacy_footprint) {
2621 		task_set_legacy_footprint(task);
2622 	}
2623 #endif /* __arm64__ */
2624 
2625 	pal_dbg_set_task_name(task);
2626 
2627 #if DEVELOPMENT || DEBUG
2628 	/*
2629 	 * Update the pid an proc name for importance base if any
2630 	 */
2631 	task_importance_update_owner_info(task);
2632 #endif
2633 
2634 	proc_setexecutableuuid(p, &load_result.uuid[0]);
2635 
2636 #if CONFIG_DTRACE
2637 	dtrace_proc_exec(p);
2638 #endif
2639 
2640 	if (kdebug_enable) {
2641 		long args[4] = {};
2642 
2643 		uintptr_t fsid = 0, fileid = 0;
2644 		if (imgp->ip_vattr) {
2645 			uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
2646 			fsid   = (uintptr_t)fsid64;
2647 			fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
2648 			// check for (unexpected) overflow and trace zero in that case
2649 			if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
2650 				fsid = fileid = 0;
2651 			}
2652 		}
2653 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
2654 		    (uintptr_t)thread_tid(thread));
2655 
2656 		extern void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
2657 		kdebug_proc_name_args(p, args);
2658 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
2659 		    args[2], args[3], (uintptr_t)thread_tid(thread));
2660 	}
2661 
2662 
2663 	/*
2664 	 * If posix_spawned with the START_SUSPENDED flag, stop the
2665 	 * process before it runs.
2666 	 */
2667 	if (imgp->ip_px_sa != NULL) {
2668 		psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
2669 		if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
2670 			proc_lock(p);
2671 			p->p_stat = SSTOP;
2672 			proc_unlock(p);
2673 			(void) task_suspend_internal(task);
2674 		}
2675 	}
2676 
2677 	/*
2678 	 * mark as execed
2679 	 */
2680 	OSBitOrAtomic(P_EXEC, &p->p_flag);
2681 	proc_resetregister(p);
2682 	if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
2683 		proc_lock(p);
2684 		p->p_lflag &= ~P_LPPWAIT;
2685 		proc_unlock(p);
2686 		wakeup((caddr_t)p->p_pptr);
2687 	}
2688 
2689 	/*
2690 	 * Set up dext coredumps on kernel panic.
2691 	 * This requires the following:
2692 	 * - dext_panic_coredump=1 boot-arg (enabled by default on DEVELOPMENT, DEBUG and certain Seed builds)
2693 	 * - process must be a driver
2694 	 * - process must have the com.apple.private.enable-coredump-on-panic entitlement, and the
2695 	 *   entitlement has a string value.
2696 	 * - process must have the com.apple.private.enable-coredump-on-panic-seed-privacy-approved
2697 	 *   entitlement (Seed builds only).
2698 	 *
2699 	 * The core dump file name is formatted with the entitlement string value, followed by a hyphen
2700 	 * and the process PID.
2701 	 */
2702 	if (enable_dext_coredumps_on_panic &&
2703 	    (imgp->ip_flags & IMGPF_DRIVER) != 0 &&
2704 	    (userspace_coredump_name = IOVnodeGetEntitlement(imgp->ip_vp,
2705 	    (int64_t)imgp->ip_arch_offset, USERSPACE_COREDUMP_PANIC_ENTITLEMENT)) != NULL) {
2706 		size_t userspace_coredump_name_len = strlen(userspace_coredump_name);
2707 
2708 		char core_name[MACH_CORE_FILEHEADER_NAMELEN];
2709 		/* 16 - NULL char - strlen("-") - maximum of 5 digits for pid */
2710 		snprintf(core_name, MACH_CORE_FILEHEADER_NAMELEN, "%.9s-%d", userspace_coredump_name, proc_getpid(p));
2711 
2712 		kern_register_userspace_coredump(task, core_name);
2713 
2714 		/* Discard the copy of the entitlement */
2715 		kfree_data(userspace_coredump_name, userspace_coredump_name_len + 1);
2716 		userspace_coredump_name = NULL;
2717 	}
2718 
2719 	goto done;
2720 
2721 badtoolate:
2722 	/* Don't allow child process to execute any instructions */
2723 	if (!spawn) {
2724 		{
2725 			assert(exec_failure_reason != OS_REASON_NULL);
2726 			if (bootarg_execfailurereports) {
2727 				set_proc_name(imgp, current_proc());
2728 			}
2729 			psignal_with_reason(current_proc(), SIGKILL, exec_failure_reason);
2730 			exec_failure_reason = OS_REASON_NULL;
2731 
2732 			if (exec) {
2733 				/* Terminate the exec copy task */
2734 				task_terminate_internal(task);
2735 			}
2736 		}
2737 
2738 		/* We can't stop this system call at this point, so just pretend we succeeded */
2739 		error = 0;
2740 	} else {
2741 		os_reason_free(exec_failure_reason);
2742 		exec_failure_reason = OS_REASON_NULL;
2743 	}
2744 
2745 done:
2746 	if (load_result.threadstate) {
2747 		kfree_data(load_result.threadstate, load_result.threadstate_sz);
2748 		load_result.threadstate = NULL;
2749 	}
2750 
2751 bad:
2752 	/* If we hit this, we likely would have leaked an exit reason */
2753 	assert(exec_failure_reason == OS_REASON_NULL);
2754 	return error;
2755 }
2756 
2757 
2758 
2759 
2760 /*
2761  * Our image activator table; this is the table of the image types we are
2762  * capable of loading.  We list them in order of preference to ensure the
2763  * fastest image load speed.
2764  *
2765  * XXX hardcoded, for now; should use linker sets
2766  */
2767 struct execsw {
2768 	int(*const ex_imgact)(struct image_params *);
2769 	const char *ex_name;
2770 }const execsw[] = {
2771 	{ exec_mach_imgact, "Mach-o Binary" },
2772 	{ exec_fat_imgact, "Fat Binary" },
2773 	{ exec_shell_imgact, "Interpreter Script" },
2774 	{ NULL, NULL}
2775 };
2776 
2777 
2778 /*
2779  * exec_activate_image
2780  *
2781  * Description:	Iterate through the available image activators, and activate
2782  *		the image associated with the imgp structure.  We start with
2783  *		the activator for Mach-o binaries followed by that for Fat binaries
2784  *		for Interpreter scripts.
2785  *
2786  * Parameters:	struct image_params *	Image parameter block
2787  *
2788  * Returns:	0			Success
2789  *		ENOEXEC			No activator for image.
2790  *		EBADEXEC		The executable is corrupt/unknown
2791  *	execargs_alloc:EINVAL		Invalid argument
2792  *	execargs_alloc:EACCES		Permission denied
2793  *	execargs_alloc:EINTR		Interrupted function
2794  *	execargs_alloc:ENOMEM		Not enough space
2795  *	exec_save_path:EFAULT		Bad address
2796  *	exec_save_path:ENAMETOOLONG	Filename too long
2797  *	exec_check_permissions:EACCES	Permission denied
2798  *	exec_check_permissions:ENOEXEC	Executable file format error
2799  *	exec_check_permissions:ETXTBSY	Text file busy [misuse of error code]
2800  *	exec_check_permissions:???
2801  *	namei:???
2802  *	vn_rdwr:???			[anything vn_rdwr can return]
2803  *	<ex_imgact>:???			[anything an imgact can return]
2804  *	EDEADLK				Process is being terminated
2805  */
2806 static int
exec_activate_image(struct image_params * imgp)2807 exec_activate_image(struct image_params *imgp)
2808 {
2809 	struct nameidata *ndp = NULL;
2810 	const char *excpath;
2811 	int error;
2812 	int resid;
2813 	int once = 1;   /* save SGUID-ness for interpreted files */
2814 	int i;
2815 	int itercount = 0;
2816 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2817 
2818 	/*
2819 	 * For exec, the translock needs to be taken on old proc and not
2820 	 * on new shadow proc.
2821 	 */
2822 	if (imgp->ip_flags & IMGPF_EXEC) {
2823 		p = current_proc();
2824 	}
2825 
2826 	error = execargs_alloc(imgp);
2827 	if (error) {
2828 		goto bad_notrans;
2829 	}
2830 
2831 	error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
2832 	if (error) {
2833 		goto bad_notrans;
2834 	}
2835 
2836 	/* Use excpath, which contains the copyin-ed exec path */
2837 	DTRACE_PROC1(exec, uintptr_t, excpath);
2838 
2839 	ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2840 
2841 	NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
2842 	    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2843 
2844 again:
2845 	error = namei(ndp);
2846 	if (error) {
2847 		if (error == ERESTART) {
2848 			error = EINTR;
2849 		}
2850 		goto bad_notrans;
2851 	}
2852 	imgp->ip_ndp = ndp;     /* successful namei(); call nameidone() later */
2853 	imgp->ip_vp = ndp->ni_vp;       /* if set, need to vnode_put() at some point */
2854 
2855 	/*
2856 	 * Before we start the transition from binary A to binary B, make
2857 	 * sure another thread hasn't started exiting the process.  We grab
2858 	 * the proc lock to check p_lflag initially, and the transition
2859 	 * mechanism ensures that the value doesn't change after we release
2860 	 * the lock.
2861 	 */
2862 	proc_lock(p);
2863 	if (p->p_lflag & P_LEXIT) {
2864 		error = EDEADLK;
2865 		proc_unlock(p);
2866 		goto bad_notrans;
2867 	}
2868 	error = proc_transstart(p, 1, 0);
2869 	proc_unlock(p);
2870 	if (error) {
2871 		goto bad_notrans;
2872 	}
2873 
2874 	error = exec_check_permissions(imgp);
2875 	if (error) {
2876 		goto bad;
2877 	}
2878 
2879 	/* Copy; avoid invocation of an interpreter overwriting the original */
2880 	if (once) {
2881 		once = 0;
2882 		*imgp->ip_origvattr = *imgp->ip_vattr;
2883 	}
2884 
2885 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
2886 	    UIO_SYSSPACE, IO_NODELOCKED,
2887 	    vfs_context_ucred(imgp->ip_vfs_context),
2888 	    &resid, vfs_context_proc(imgp->ip_vfs_context));
2889 	if (error) {
2890 		goto bad;
2891 	}
2892 
2893 	if (resid) {
2894 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
2895 	}
2896 
2897 encapsulated_binary:
2898 	/* Limit the number of iterations we will attempt on each binary */
2899 	if (++itercount > EAI_ITERLIMIT) {
2900 		error = EBADEXEC;
2901 		goto bad;
2902 	}
2903 	error = -1;
2904 	for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
2905 		error = (*execsw[i].ex_imgact)(imgp);
2906 
2907 		switch (error) {
2908 		/* case -1: not claimed: continue */
2909 		case -2:                /* Encapsulated binary, imgp->ip_XXX set for next iteration */
2910 			goto encapsulated_binary;
2911 
2912 		case -3:                /* Interpreter */
2913 #if CONFIG_MACF
2914 			/*
2915 			 * Copy the script label for later use. Note that
2916 			 * the label can be different when the script is
2917 			 * actually read by the interpreter.
2918 			 */
2919 			if (imgp->ip_scriptlabelp) {
2920 				mac_vnode_label_free(imgp->ip_scriptlabelp);
2921 				imgp->ip_scriptlabelp = NULL;
2922 			}
2923 			imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
2924 			if (imgp->ip_scriptlabelp == NULL) {
2925 				error = ENOMEM;
2926 				break;
2927 			}
2928 			mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
2929 			    imgp->ip_scriptlabelp);
2930 
2931 			/*
2932 			 * Take a ref of the script vnode for later use.
2933 			 */
2934 			if (imgp->ip_scriptvp) {
2935 				vnode_put(imgp->ip_scriptvp);
2936 				imgp->ip_scriptvp = NULLVP;
2937 			}
2938 			if (vnode_getwithref(imgp->ip_vp) == 0) {
2939 				imgp->ip_scriptvp = imgp->ip_vp;
2940 			}
2941 #endif
2942 
2943 			nameidone(ndp);
2944 
2945 			vnode_put(imgp->ip_vp);
2946 			imgp->ip_vp = NULL;     /* already put */
2947 			imgp->ip_ndp = NULL; /* already nameidone */
2948 
2949 			/* Use excpath, which exec_shell_imgact reset to the interpreter */
2950 			NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
2951 			    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2952 
2953 			proc_transend(p, 0);
2954 			goto again;
2955 
2956 		default:
2957 			break;
2958 		}
2959 	}
2960 
2961 	if (error == -1) {
2962 		error = ENOEXEC;
2963 	} else if (error == 0) {
2964 		if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
2965 			AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
2966 		}
2967 
2968 		/*
2969 		 * Call out to allow 3rd party notification of exec.
2970 		 * Ignore result of kauth_authorize_fileop call.
2971 		 */
2972 		if (kauth_authorize_fileop_has_listeners()) {
2973 			kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
2974 			    KAUTH_FILEOP_EXEC,
2975 			    (uintptr_t)ndp->ni_vp, 0);
2976 		}
2977 	}
2978 bad:
2979 	proc_transend(p, 0);
2980 
2981 bad_notrans:
2982 	if (imgp->ip_strings) {
2983 		execargs_free(imgp);
2984 	}
2985 	if (imgp->ip_ndp) {
2986 		nameidone(imgp->ip_ndp);
2987 	}
2988 	kfree_type(struct nameidata, ndp);
2989 
2990 	return error;
2991 }
2992 
2993 
2994 /*
2995  * exec_validate_spawnattr_policy
2996  *
2997  * Description: Validates the entitlements required to set the apptype.
2998  *
2999  * Parameters:  int psa_apptype         posix spawn attribute apptype
3000  *
3001  * Returns:     0                       Success
3002  *              EPERM                   Failure
3003  */
3004 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)3005 exec_validate_spawnattr_policy(int psa_apptype)
3006 {
3007 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
3008 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
3009 		if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
3010 			if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
3011 				return EPERM;
3012 			}
3013 		}
3014 	}
3015 
3016 	return 0;
3017 }
3018 
3019 /*
3020  * exec_handle_spawnattr_policy
3021  *
3022  * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
3023  *
3024  * Parameters:  proc_t p                process to apply attributes to
3025  *              int psa_apptype         posix spawn attribute apptype
3026  *
3027  * Returns:     0                       Success
3028  */
3029 static errno_t
exec_handle_spawnattr_policy(proc_t p,thread_t thread,int psa_apptype,uint64_t psa_qos_clamp,task_role_t psa_darwin_role,struct exec_port_actions * port_actions)3030 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
3031     task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
3032 {
3033 	int apptype     = TASK_APPTYPE_NONE;
3034 	int qos_clamp   = THREAD_QOS_UNSPECIFIED;
3035 	task_role_t role = TASK_UNSPECIFIED;
3036 
3037 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
3038 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
3039 
3040 		switch (proctype) {
3041 		case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
3042 			apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
3043 			break;
3044 		case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
3045 			apptype = TASK_APPTYPE_DAEMON_STANDARD;
3046 			break;
3047 		case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
3048 			apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
3049 			break;
3050 		case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
3051 			apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
3052 			break;
3053 		case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
3054 			apptype = TASK_APPTYPE_APP_DEFAULT;
3055 			break;
3056 		case POSIX_SPAWN_PROC_TYPE_APP_NONUI:
3057 			apptype = TASK_APPTYPE_APP_NONUI;
3058 			break;
3059 		case POSIX_SPAWN_PROC_TYPE_DRIVER:
3060 			apptype = TASK_APPTYPE_DRIVER;
3061 			break;
3062 		default:
3063 			apptype = TASK_APPTYPE_NONE;
3064 			/* TODO: Should an invalid value here fail the spawn? */
3065 			break;
3066 		}
3067 	}
3068 
3069 	if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
3070 		switch (psa_qos_clamp) {
3071 		case POSIX_SPAWN_PROC_CLAMP_UTILITY:
3072 			qos_clamp = THREAD_QOS_UTILITY;
3073 			break;
3074 		case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
3075 			qos_clamp = THREAD_QOS_BACKGROUND;
3076 			break;
3077 		case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
3078 			qos_clamp = THREAD_QOS_MAINTENANCE;
3079 			break;
3080 		default:
3081 			qos_clamp = THREAD_QOS_UNSPECIFIED;
3082 			/* TODO: Should an invalid value here fail the spawn? */
3083 			break;
3084 		}
3085 	}
3086 
3087 	if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
3088 		proc_darwin_role_to_task_role(psa_darwin_role, &role);
3089 	}
3090 
3091 	if (apptype != TASK_APPTYPE_NONE ||
3092 	    qos_clamp != THREAD_QOS_UNSPECIFIED ||
3093 	    role != TASK_UNSPECIFIED ||
3094 	    port_actions->portwatch_count) {
3095 		proc_set_task_spawnpolicy(proc_task(p), thread, apptype, qos_clamp, role,
3096 		    port_actions->portwatch_array, port_actions->portwatch_count);
3097 	}
3098 
3099 	if (port_actions->registered_count) {
3100 		if (_kernelrpc_mach_ports_register3(proc_task(p),
3101 		    port_actions->registered_array[0],
3102 		    port_actions->registered_array[1],
3103 		    port_actions->registered_array[2])) {
3104 			return EINVAL;
3105 		}
3106 		/* mach_ports_register() consumed the array */
3107 		bzero(port_actions->registered_array,
3108 		    sizeof(port_actions->registered_array));
3109 		port_actions->registered_count = 0;
3110 	}
3111 
3112 	return 0;
3113 }
3114 
3115 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)3116 exec_port_actions_destroy(struct exec_port_actions *port_actions)
3117 {
3118 	if (port_actions->excport_array) {
3119 		for (uint32_t i = 0; i < port_actions->exception_port_count; i++) {
3120 			ipc_port_t port = NULL;
3121 			if ((port = port_actions->excport_array[i].port) != NULL) {
3122 				ipc_port_release_send(port);
3123 			}
3124 		}
3125 		kfree_type(struct exception_port_action_t, port_actions->exception_port_count,
3126 		    port_actions->excport_array);
3127 	}
3128 
3129 	if (port_actions->portwatch_array) {
3130 		for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
3131 			ipc_port_t port = NULL;
3132 			if ((port = port_actions->portwatch_array[i]) != NULL) {
3133 				ipc_port_release_send(port);
3134 			}
3135 		}
3136 		kfree_type(ipc_port_t, port_actions->portwatch_count,
3137 		    port_actions->portwatch_array);
3138 	}
3139 
3140 	for (uint32_t i = 0; i < port_actions->registered_count; i++) {
3141 		ipc_port_t port = NULL;
3142 		if ((port = port_actions->registered_array[i]) != NULL) {
3143 			ipc_port_release_send(port);
3144 		}
3145 	}
3146 }
3147 
3148 /*
3149  * exec_handle_port_actions
3150  *
3151  * Description:	Go through the _posix_port_actions_t contents,
3152  *              calling task_set_special_port, task_set_exception_ports
3153  *              and/or audit_session_spawnjoin for the current task.
3154  *
3155  * Parameters:	struct image_params *	Image parameter block
3156  *
3157  * Returns:	0			Success
3158  *              EINVAL			Failure
3159  *              ENOTSUP			Illegal posix_spawn attr flag was set
3160  */
3161 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)3162 exec_handle_port_actions(struct image_params *imgp,
3163     struct exec_port_actions *actions)
3164 {
3165 	_posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
3166 #if CONFIG_AUDIT
3167 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
3168 #endif
3169 	_ps_port_action_t *act = NULL;
3170 	task_t task = get_threadtask(imgp->ip_new_thread);
3171 	ipc_port_t port = NULL;
3172 	errno_t ret = 0;
3173 	int i = 0, portwatch_i = 0, registered_i = 0, excport_i = 0;
3174 	kern_return_t kr;
3175 	boolean_t task_has_watchport_boost = task_has_watchports(current_task());
3176 	boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
3177 	int ptrauth_task_port_count = 0;
3178 
3179 	for (i = 0; i < pacts->pspa_count; i++) {
3180 		act = &pacts->pspa_actions[i];
3181 
3182 		switch (act->port_type) {
3183 		case PSPA_SPECIAL:
3184 #if CONFIG_AUDIT
3185 		case PSPA_AU_SESSION:
3186 #endif
3187 			break;
3188 		case PSPA_EXCEPTION:
3189 			if (++actions->exception_port_count > TASK_MAX_EXCEPTION_PORT_COUNT) {
3190 				ret = EINVAL;
3191 				goto done;
3192 			}
3193 			break;
3194 		case PSPA_IMP_WATCHPORTS:
3195 			if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
3196 				ret = EINVAL;
3197 				goto done;
3198 			}
3199 			break;
3200 		case PSPA_REGISTERED_PORTS:
3201 			if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
3202 				ret = EINVAL;
3203 				goto done;
3204 			}
3205 			break;
3206 		case PSPA_PTRAUTH_TASK_PORT:
3207 			if (++ptrauth_task_port_count > 1) {
3208 				ret = EINVAL;
3209 				goto done;
3210 			}
3211 			break;
3212 		default:
3213 			ret = EINVAL;
3214 			goto done;
3215 		}
3216 	}
3217 
3218 	if (actions->exception_port_count) {
3219 		actions->excport_array = kalloc_type(struct exception_port_action_t,
3220 		    actions->exception_port_count, Z_WAITOK | Z_ZERO);
3221 
3222 		if (actions->excport_array == NULL) {
3223 			ret = ENOMEM;
3224 			goto done;
3225 		}
3226 	}
3227 	if (actions->portwatch_count) {
3228 		if (in_exec && task_has_watchport_boost) {
3229 			ret = EINVAL;
3230 			goto done;
3231 		}
3232 		actions->portwatch_array = kalloc_type(ipc_port_t,
3233 		    actions->portwatch_count, Z_WAITOK | Z_ZERO);
3234 		if (actions->portwatch_array == NULL) {
3235 			ret = ENOMEM;
3236 			goto done;
3237 		}
3238 	}
3239 
3240 	for (i = 0; i < pacts->pspa_count; i++) {
3241 		act = &pacts->pspa_actions[i];
3242 
3243 		if (MACH_PORT_VALID(act->new_port)) {
3244 			kr = ipc_typed_port_copyin_send(get_task_ipcspace(current_task()),
3245 			    act->new_port, IOT_ANY, &port);
3246 
3247 			if (kr != KERN_SUCCESS) {
3248 				ret = EINVAL;
3249 				goto done;
3250 			}
3251 		} else {
3252 			/* it's NULL or DEAD */
3253 			port = CAST_MACH_NAME_TO_PORT(act->new_port);
3254 		}
3255 
3256 		switch (act->port_type) {
3257 		case PSPA_SPECIAL:
3258 			kr = task_set_special_port(task, act->which, port);
3259 
3260 			if (kr != KERN_SUCCESS) {
3261 				ret = EINVAL;
3262 			}
3263 			break;
3264 
3265 #if CONFIG_AUDIT
3266 		case PSPA_AU_SESSION:
3267 			ret = audit_session_spawnjoin(p, port);
3268 			if (ret) {
3269 				/* audit_session_spawnjoin() has already dropped the reference in case of error. */
3270 				goto done;
3271 			}
3272 
3273 			break;
3274 #endif
3275 		case PSPA_EXCEPTION:
3276 			assert(excport_i < actions->exception_port_count);
3277 			/* hold on to this till end of spawn */
3278 			actions->excport_array[excport_i].port_action = act;
3279 			actions->excport_array[excport_i].port = port;
3280 			excport_i++;
3281 			break;
3282 		case PSPA_IMP_WATCHPORTS:
3283 			assert(portwatch_i < actions->portwatch_count);
3284 			/* hold on to this till end of spawn */
3285 			actions->portwatch_array[portwatch_i++] = port;
3286 			break;
3287 		case PSPA_REGISTERED_PORTS:
3288 			assert(registered_i < actions->registered_count);
3289 			/* hold on to this till end of spawn */
3290 			actions->registered_array[registered_i++] = port;
3291 			break;
3292 
3293 		case PSPA_PTRAUTH_TASK_PORT:
3294 #if (DEVELOPMENT || DEBUG)
3295 #if defined(HAS_APPLE_PAC)
3296 			{
3297 				task_t ptr_auth_task = convert_port_to_task(port);
3298 
3299 				if (ptr_auth_task == TASK_NULL) {
3300 					ret = EINVAL;
3301 					break;
3302 				}
3303 
3304 				imgp->ip_inherited_shared_region_id =
3305 				    task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
3306 				    &imgp->ip_inherited_jop_pid);
3307 
3308 				/* Deallocate task ref returned by convert_port_to_task */
3309 				task_deallocate(ptr_auth_task);
3310 			}
3311 #endif /* HAS_APPLE_PAC */
3312 #endif /* (DEVELOPMENT || DEBUG) */
3313 
3314 			/* consume the port right in case of success */
3315 			ipc_port_release_send(port);
3316 			break;
3317 		default:
3318 			ret = EINVAL;
3319 			break;
3320 		}
3321 
3322 		if (ret) {
3323 			/* action failed, so release port resources */
3324 			ipc_port_release_send(port);
3325 			break;
3326 		}
3327 	}
3328 
3329 done:
3330 	if (0 != ret) {
3331 		DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
3332 	}
3333 	return ret;
3334 }
3335 
3336 
3337 /*
3338  * exec_handle_exception_port_actions
3339  *
3340  * Description:	Go through the saved exception ports in exec_port_actions,
3341  *              calling task_set_exception_ports for the current Task.
3342  *              This must happen after image activation, and after exec_resettextvp()
3343  *				because task_set_exception_ports checks the `TF_PLATFORM` bit and entitlements.
3344  *
3345  * Parameters:	struct image_params *		Image parameter block
3346  *                              struct exec_port_actions *  Saved Port Actions
3347  *
3348  * Returns:	0			Success
3349  *              EINVAL			task_set_exception_ports failed
3350  */
3351 static errno_t
exec_handle_exception_port_actions(const struct image_params * imgp,const struct exec_port_actions * actions)3352 exec_handle_exception_port_actions(const struct image_params *imgp,
3353     const struct exec_port_actions *actions)
3354 {
3355 	task_t task = get_threadtask(imgp->ip_new_thread);
3356 
3357 	for (int i = 0; i < actions->exception_port_count; i++) {
3358 		ipc_port_t port = actions->excport_array[i].port;
3359 		_ps_port_action_t *act = actions->excport_array[i].port_action;
3360 		assert(act != NULL);
3361 		kern_return_t kr = task_set_exception_ports(task, act->mask, port,
3362 		    act->behavior, act->flavor);
3363 		if (kr != KERN_SUCCESS) {
3364 			DTRACE_PROC1(spawn__exception__port__failure, mach_port_name_t, act->new_port);
3365 			return EINVAL;
3366 		}
3367 		actions->excport_array[i].port = NULL;
3368 	}
3369 
3370 	return 0;
3371 }
3372 
3373 
3374 /*
3375  * exec_handle_file_actions
3376  *
3377  * Description:	Go through the _posix_file_actions_t contents applying the
3378  *		open, close, and dup2 operations to the open file table for
3379  *		the current process.
3380  *
3381  * Parameters:	struct image_params *	Image parameter block
3382  *
3383  * Returns:	0			Success
3384  *		???
3385  *
3386  * Note:	Actions are applied in the order specified, with the credential
3387  *		of the parent process.  This is done to permit the parent
3388  *		process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
3389  *		the child following operations the child may in fact not be
3390  *		normally permitted to perform.
3391  */
3392 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)3393 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
3394 {
3395 	int error = 0;
3396 	int action;
3397 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
3398 	kauth_cred_t p_cred = vfs_context_ucred(imgp->ip_vfs_context);
3399 	_posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
3400 	int ival[2];            /* dummy retval for system calls) */
3401 #if CONFIG_AUDIT
3402 	struct uthread *uthread = current_uthread();
3403 #endif
3404 
3405 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
3406 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3407 
3408 		switch (psfa->psfaa_type) {
3409 		case PSFA_OPEN: {
3410 			/*
3411 			 * Open is different, in that it requires the use of
3412 			 * a path argument, which is normally copied in from
3413 			 * user space; because of this, we have to support an
3414 			 * open from kernel space that passes an address space
3415 			 * context of UIO_SYSSPACE, and casts the address
3416 			 * argument to a user_addr_t.
3417 			 */
3418 			struct vnode_attr *vap;
3419 			struct nameidata *ndp;
3420 			int mode = psfa->psfaa_openargs.psfao_mode;
3421 			int origfd;
3422 			struct {
3423 				struct vnode_attr va;
3424 				struct nameidata nd;
3425 			} *__open_data;
3426 
3427 			__open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
3428 			if (__open_data == NULL) {
3429 				error = ENOMEM;
3430 				break;
3431 			}
3432 
3433 			vap = &__open_data->va;
3434 			ndp = &__open_data->nd;
3435 
3436 			VATTR_INIT(vap);
3437 			/* Mask off all but regular access permissions */
3438 			mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
3439 			VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
3440 
3441 			AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
3442 
3443 			NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
3444 			    CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
3445 			    imgp->ip_vfs_context);
3446 
3447 			error = open1(imgp->ip_vfs_context, ndp,
3448 			    psfa->psfaa_openargs.psfao_oflag,
3449 			    vap, NULL, NULL, &origfd, AUTH_OPEN_NOAUTHFD);
3450 
3451 			kfree_type(typeof(*__open_data), __open_data);
3452 
3453 			AUDIT_SUBCALL_EXIT(uthread, error);
3454 
3455 			/*
3456 			 * If there's an error, or we get the right fd by
3457 			 * accident, then drop out here.  This is easier than
3458 			 * reworking all the open code to preallocate fd
3459 			 * slots, and internally taking one as an argument.
3460 			 */
3461 			if (error || origfd == psfa->psfaa_filedes) {
3462 				break;
3463 			}
3464 
3465 			/*
3466 			 * If we didn't fall out from an error, we ended up
3467 			 * with the wrong fd; so now we've got to try to dup2
3468 			 * it to the right one.
3469 			 */
3470 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
3471 			error = dup2(p, p_cred, origfd, psfa->psfaa_filedes, ival);
3472 			AUDIT_SUBCALL_EXIT(uthread, error);
3473 			if (error) {
3474 				break;
3475 			}
3476 
3477 			/*
3478 			 * Finally, close the original fd.
3479 			 */
3480 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
3481 			error = close_nocancel(p, p_cred, origfd);
3482 			AUDIT_SUBCALL_EXIT(uthread, error);
3483 		}
3484 		break;
3485 
3486 		case PSFA_DUP2: {
3487 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
3488 			error = dup2(p, p_cred, psfa->psfaa_filedes,
3489 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
3490 			AUDIT_SUBCALL_EXIT(uthread, error);
3491 		}
3492 		break;
3493 
3494 		case PSFA_FILEPORT_DUP2: {
3495 			ipc_port_t port;
3496 			kern_return_t kr;
3497 			int origfd;
3498 
3499 			if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
3500 				error = EINVAL;
3501 				break;
3502 			}
3503 
3504 			kr = ipc_typed_port_copyin_send(get_task_ipcspace(current_task()),
3505 			    psfa->psfaa_fileport, IKOT_FILEPORT, &port);
3506 
3507 			if (kr != KERN_SUCCESS) {
3508 				error = EINVAL;
3509 				break;
3510 			}
3511 
3512 			error = fileport_makefd(p, port, 0, &origfd);
3513 
3514 			if (IPC_PORT_NULL != port) {
3515 				ipc_typed_port_release_send(port, IKOT_FILEPORT);
3516 			}
3517 
3518 			if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
3519 				break;
3520 			}
3521 
3522 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
3523 			error = dup2(p, p_cred, origfd,
3524 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
3525 			AUDIT_SUBCALL_EXIT(uthread, error);
3526 			if (error) {
3527 				break;
3528 			}
3529 
3530 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
3531 			error = close_nocancel(p, p_cred, origfd);
3532 			AUDIT_SUBCALL_EXIT(uthread, error);
3533 		}
3534 		break;
3535 
3536 		case PSFA_CLOSE: {
3537 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
3538 			error = close_nocancel(p, p_cred, psfa->psfaa_filedes);
3539 			AUDIT_SUBCALL_EXIT(uthread, error);
3540 		}
3541 		break;
3542 
3543 		case PSFA_INHERIT: {
3544 			struct fileproc *fp;
3545 
3546 			/*
3547 			 * Check to see if the descriptor exists, and
3548 			 * ensure it's -not- marked as close-on-exec.
3549 			 *
3550 			 * Attempting to "inherit" a guarded fd will
3551 			 * result in a error.
3552 			 */
3553 
3554 			proc_fdlock(p);
3555 			if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
3556 				error = EBADF;
3557 			} else if (fp->fp_guard_attrs) {
3558 				error = fp_guard_exception(p, psfa->psfaa_filedes,
3559 				    fp, kGUARD_EXC_NOCLOEXEC);
3560 			} else {
3561 				fp->fp_flags &= ~FP_CLOEXEC;
3562 				error = 0;
3563 			}
3564 			proc_fdunlock(p);
3565 		}
3566 		break;
3567 
3568 		case PSFA_CHDIR: {
3569 			/*
3570 			 * Chdir is different, in that it requires the use of
3571 			 * a path argument, which is normally copied in from
3572 			 * user space; because of this, we have to support a
3573 			 * chdir from kernel space that passes an address space
3574 			 * context of UIO_SYSSPACE, and casts the address
3575 			 * argument to a user_addr_t.
3576 			 */
3577 			struct nameidata *nd;
3578 			nd = kalloc_type(struct nameidata,
3579 			    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3580 
3581 			AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
3582 			NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
3583 			    CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
3584 			    imgp->ip_vfs_context);
3585 
3586 			error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
3587 			kfree_type(struct nameidata, nd);
3588 			AUDIT_SUBCALL_EXIT(uthread, error);
3589 		}
3590 		break;
3591 
3592 		case PSFA_FCHDIR: {
3593 			AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
3594 			error = fchdir(p, imgp->ip_vfs_context,
3595 			    psfa->psfaa_filedes, false);
3596 			AUDIT_SUBCALL_EXIT(uthread, error);
3597 		}
3598 		break;
3599 
3600 		default:
3601 			error = EINVAL;
3602 			break;
3603 		}
3604 
3605 		/* All file actions failures are considered fatal, per POSIX */
3606 
3607 		if (error) {
3608 			if (PSFA_OPEN == psfa->psfaa_type) {
3609 				DTRACE_PROC1(spawn__open__failure, uintptr_t,
3610 				    psfa->psfaa_openargs.psfao_path);
3611 			} else {
3612 				DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
3613 			}
3614 			break;
3615 		}
3616 	}
3617 
3618 	if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
3619 		return error;
3620 	}
3621 
3622 	/*
3623 	 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
3624 	 * this spawn only) as if "close on exec" is the default
3625 	 * disposition of all pre-existing file descriptors.  In this case,
3626 	 * the list of file descriptors mentioned in the file actions
3627 	 * are the only ones that can be inherited, so mark them now.
3628 	 *
3629 	 * The actual closing part comes later, in fdt_exec().
3630 	 */
3631 	proc_fdlock(p);
3632 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
3633 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3634 		int fd = psfa->psfaa_filedes;
3635 
3636 		switch (psfa->psfaa_type) {
3637 		case PSFA_DUP2:
3638 		case PSFA_FILEPORT_DUP2:
3639 			fd = psfa->psfaa_dup2args.psfad_newfiledes;
3640 			OS_FALLTHROUGH;
3641 		case PSFA_OPEN:
3642 		case PSFA_INHERIT:
3643 			*fdflags(p, fd) |= UF_INHERIT;
3644 			break;
3645 
3646 		case PSFA_CLOSE:
3647 		case PSFA_CHDIR:
3648 		case PSFA_FCHDIR:
3649 			/*
3650 			 * Although PSFA_FCHDIR does have a file descriptor, it is not
3651 			 * *creating* one, thus we do not automatically mark it for
3652 			 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
3653 			 * wishes it to be inherited should use the PSFA_INHERIT action
3654 			 * explicitly.
3655 			 */
3656 			break;
3657 		}
3658 	}
3659 	proc_fdunlock(p);
3660 
3661 	return 0;
3662 }
3663 
3664 #if CONFIG_MACF
3665 /*
3666  * Check that the extension's data is within the bounds of the
3667  * allocation storing all extensions' data
3668  */
3669 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)3670 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
3671     const _ps_mac_policy_extension_t *ext)
3672 {
3673 	uint64_t dataend;
3674 
3675 	if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
3676 		return EOVERFLOW;
3677 	}
3678 	if (__improbable(dataend > px_s->datalen)) {
3679 		return EINVAL;
3680 	}
3681 
3682 	return 0;
3683 }
3684 
3685 /*
3686  * exec_spawnattr_getmacpolicyinfo
3687  */
3688 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)3689 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
3690 {
3691 	const struct ip_px_smpx_s *px_s = macextensions;
3692 	const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
3693 	int i;
3694 
3695 	if (px_s == NULL) {
3696 		return NULL;
3697 	}
3698 
3699 	psmx = px_s->array;
3700 	if (psmx == NULL) {
3701 		return NULL;
3702 	}
3703 
3704 	for (i = 0; i < psmx->psmx_count; i++) {
3705 		const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3706 		if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
3707 			if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
3708 				panic("invalid mac policy extension data");
3709 			}
3710 			if (lenp != NULL) {
3711 				*lenp = (size_t)extension->datalen;
3712 			}
3713 			return (void *)((uintptr_t)px_s->data + extension->dataoff);
3714 		}
3715 	}
3716 
3717 	if (lenp != NULL) {
3718 		*lenp = 0;
3719 	}
3720 	return NULL;
3721 }
3722 
3723 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)3724 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
3725     struct ip_px_smpx_s *pxsp)
3726 {
3727 	_posix_spawn_mac_policy_extensions_t psmx = NULL;
3728 	uint8_t *data = NULL;
3729 	uint64_t datalen = 0;
3730 	uint64_t dataoff = 0;
3731 	int error = 0;
3732 
3733 	bzero(pxsp, sizeof(*pxsp));
3734 
3735 	if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
3736 	    px_args->mac_extensions_size > PAGE_SIZE) {
3737 		error = EINVAL;
3738 		goto bad;
3739 	}
3740 
3741 	psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
3742 	if (psmx == NULL) {
3743 		error = ENOMEM;
3744 		goto bad;
3745 	}
3746 
3747 	error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
3748 	if (error) {
3749 		goto bad;
3750 	}
3751 
3752 	size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
3753 	if (extsize == 0 || extsize > px_args->mac_extensions_size) {
3754 		error = EINVAL;
3755 		goto bad;
3756 	}
3757 
3758 	for (int i = 0; i < psmx->psmx_count; i++) {
3759 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3760 		if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
3761 			error = EINVAL;
3762 			goto bad;
3763 		}
3764 		if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
3765 			error = ENOMEM;
3766 			goto bad;
3767 		}
3768 	}
3769 
3770 	data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
3771 	if (data == NULL) {
3772 		error = ENOMEM;
3773 		goto bad;
3774 	}
3775 
3776 	for (int i = 0; i < psmx->psmx_count; i++) {
3777 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3778 
3779 #if !__LP64__
3780 		if (extension->data > UINT32_MAX) {
3781 			goto bad;
3782 		}
3783 #endif
3784 		error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
3785 		if (error) {
3786 			error = ENOMEM;
3787 			goto bad;
3788 		}
3789 		extension->dataoff = dataoff;
3790 		dataoff += extension->datalen;
3791 	}
3792 
3793 	pxsp->array = psmx;
3794 	pxsp->data = data;
3795 	pxsp->datalen = datalen;
3796 	return 0;
3797 
3798 bad:
3799 	kfree_data(psmx, px_args->mac_extensions_size);
3800 	kfree_data(data, (vm_size_t)datalen);
3801 	return error;
3802 }
3803 #endif /* CONFIG_MACF */
3804 
3805 #if CONFIG_COALITIONS
3806 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])3807 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
3808 {
3809 	for (int c = 0; c < COALITION_NUM_TYPES; c++) {
3810 		if (coal[c]) {
3811 			coalition_remove_active(coal[c]);
3812 			coalition_release(coal[c]);
3813 		}
3814 	}
3815 }
3816 #endif
3817 
3818 #if CONFIG_PERSONAS
3819 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)3820 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
3821 {
3822 	int error = 0;
3823 	struct persona *persona = NULL;
3824 	kauth_cred_t mycred = kauth_cred_get();
3825 
3826 	if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
3827 		return EPERM;
3828 	}
3829 
3830 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3831 		if (px_persona->pspi_ngroups > NGROUPS_MAX) {
3832 			return EINVAL;
3833 		}
3834 	}
3835 
3836 	persona = persona_lookup(px_persona->pspi_id);
3837 	if (!persona) {
3838 		return ESRCH;
3839 	}
3840 
3841 	// non-root process should not be allowed to set persona with uid/gid 0
3842 	if (!kauth_cred_issuser(mycred) &&
3843 	    (px_persona->pspi_uid == 0 || px_persona->pspi_gid == 0)) {
3844 		return EPERM;
3845 	}
3846 
3847 	persona_put(persona);
3848 	return error;
3849 }
3850 
3851 static bool
kauth_cred_model_setpersona(kauth_cred_t model,struct _posix_spawn_persona_info * px_persona)3852 kauth_cred_model_setpersona(
3853 	kauth_cred_t            model,
3854 	struct _posix_spawn_persona_info *px_persona)
3855 {
3856 	bool updated = false;
3857 
3858 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
3859 		updated |= kauth_cred_model_setresuid(model,
3860 		    px_persona->pspi_uid,
3861 		    px_persona->pspi_uid,
3862 		    px_persona->pspi_uid,
3863 		    KAUTH_UID_NONE);
3864 	}
3865 
3866 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
3867 		updated |= kauth_cred_model_setresgid(model,
3868 		    px_persona->pspi_gid,
3869 		    px_persona->pspi_gid,
3870 		    px_persona->pspi_gid);
3871 	}
3872 
3873 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3874 		updated |= kauth_cred_model_setgroups(model,
3875 		    px_persona->pspi_groups,
3876 		    px_persona->pspi_ngroups,
3877 		    px_persona->pspi_gmuid);
3878 	}
3879 
3880 	return updated;
3881 }
3882 
3883 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)3884 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
3885 {
3886 	struct persona *persona = NULL;
3887 
3888 	/*
3889 	 * we want to spawn into the given persona, but we want to override
3890 	 * the kauth with a different UID/GID combo
3891 	 */
3892 	persona = persona_lookup(px_persona->pspi_id);
3893 	if (!persona) {
3894 		return ESRCH;
3895 	}
3896 
3897 	return persona_proc_adopt(p, persona,
3898 	           ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
3899 		return kauth_cred_model_setpersona(model, px_persona);
3900 	});
3901 }
3902 #endif
3903 
3904 #if __arm64__
3905 #if DEVELOPMENT || DEBUG
3906 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
3907     LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
3908 
3909 __startup_func
3910 static void
legacy_footprint_entitlement_mode_init(void)3911 legacy_footprint_entitlement_mode_init(void)
3912 {
3913 	/*
3914 	 * legacy_footprint_entitlement_mode specifies the behavior we want associated
3915 	 * with the entitlement. The supported modes are:
3916 	 *
3917 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3918 	 *	Indicates that we want every process to have the memory accounting
3919 	 *	that is available in iOS 12.0 and beyond.
3920 	 *
3921 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3922 	 *	Indicates that for every process that has the 'legacy footprint entitlement',
3923 	 *      we want to give it the old iOS 11.0 accounting behavior which accounted some
3924 	 *	of the process's memory to the kernel.
3925 	 *
3926 	 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3927 	 *      Indicates that for every process that has the 'legacy footprint entitlement',
3928 	 *	we want it to have a higher memory limit which will help them acclimate to the
3929 	 *	iOS 12.0 (& beyond) accounting behavior that does the right accounting.
3930 	 *      The bonus added to the system-wide task limit to calculate this higher memory limit
3931 	 *      is available in legacy_footprint_bonus_mb.
3932 	 */
3933 
3934 	if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
3935 	    legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
3936 		legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
3937 	}
3938 }
3939 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
3940 #else
3941 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
3942 #endif
3943 
3944 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)3945 proc_legacy_footprint_entitled(proc_t p, task_t task)
3946 {
3947 #pragma unused(p)
3948 	boolean_t legacy_footprint_entitled;
3949 
3950 	switch (legacy_footprint_entitlement_mode) {
3951 	case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3952 		/* the entitlement is ignored */
3953 		break;
3954 	case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3955 		/* the entitlement grants iOS11 legacy accounting */
3956 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3957 		if (legacy_footprint_entitled) {
3958 			task_set_legacy_footprint(task);
3959 		}
3960 		break;
3961 	case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3962 		/* the entitlement grants a footprint limit increase */
3963 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3964 		if (legacy_footprint_entitled) {
3965 			task_set_extra_footprint_limit(task);
3966 		}
3967 		break;
3968 	default:
3969 		break;
3970 	}
3971 }
3972 
3973 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)3974 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
3975 {
3976 #pragma unused(p)
3977 	boolean_t ios13extended_footprint_entitled;
3978 
3979 	/* the entitlement grants a footprint limit increase */
3980 	ios13extended_footprint_entitled = memorystatus_task_has_ios13extended_footprint_limit(proc_task(p));
3981 	if (ios13extended_footprint_entitled) {
3982 		task_set_ios13extended_footprint_limit(task);
3983 	}
3984 }
3985 
3986 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)3987 proc_increased_memory_limit_entitled(proc_t p, task_t task)
3988 {
3989 	if (memorystatus_task_has_increased_debugging_memory_limit_entitlement(task)) {
3990 		memorystatus_act_on_entitled_developer_task_limit(p);
3991 	} else if (memorystatus_task_has_increased_memory_limit_entitlement(task)) {
3992 		memorystatus_act_on_entitled_task_limit(p);
3993 	}
3994 }
3995 
3996 /*
3997  * Check for any of the various entitlements that permit a higher
3998  * task footprint limit or alternate accounting and apply them.
3999  */
4000 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)4001 proc_footprint_entitlement_hacks(proc_t p, task_t task)
4002 {
4003 	proc_legacy_footprint_entitled(p, task);
4004 	proc_ios13extended_footprint_entitled(p, task);
4005 	proc_increased_memory_limit_entitled(p, task);
4006 }
4007 #endif /* __arm64__ */
4008 
4009 /*
4010  * Processes with certain entitlements are granted a jumbo-size VM map.
4011  */
4012 static inline void
proc_apply_jit_and_vm_policies(struct image_params * imgp,proc_t p,task_t task)4013 proc_apply_jit_and_vm_policies(struct image_params *imgp, proc_t p, task_t task)
4014 {
4015 #if CONFIG_MACF
4016 	bool jit_entitled = false;
4017 #endif /* CONFIG_MACF */
4018 	bool needs_jumbo_va = false;
4019 	bool needs_extra_jumbo_va = false;
4020 	struct _posix_spawnattr *psa = imgp->ip_px_sa;
4021 
4022 #if CONFIG_MACF
4023 	jit_entitled = (mac_proc_check_map_anon(p, proc_ucred_unsafe(p),
4024 	    0, 0, 0, MAP_JIT, NULL) == 0);
4025 	needs_jumbo_va = jit_entitled || IOTaskHasEntitlement(task,
4026 	    "com.apple.developer.kernel.extended-virtual-addressing") ||
4027 	    memorystatus_task_has_increased_memory_limit_entitlement(task) ||
4028 	    memorystatus_task_has_increased_debugging_memory_limit_entitlement(task);
4029 #else
4030 #pragma unused(p)
4031 #endif /* CONFIG_MACF */
4032 
4033 #if HAS_MTE
4034 	/*
4035 	 * If we are MTE enabled, communicate to the pmap layer that
4036 	 * we need the right configuration at each context switch.
4037 	 */
4038 	if (task_has_sec(task)) {
4039 		vm_map_set_sec_enabled(get_task_map(task));
4040 
4041 #if KERN_AMFI_SUPPORTS_MTE
4042 		if (get_lockdown_mode_state() == 0 &&
4043 		    amfi->has_mte_soft_mode &&
4044 		    amfi->has_mte_soft_mode(p)) {
4045 			EXEC_LOG("AMFI says: enable soft-mode\n");
4046 			task_set_sec_soft_mode(task);
4047 		}
4048 #endif /* KERN_AMFI_SUPPORTS_MTE */
4049 	}
4050 
4051 	/* Pipe through alias restrictions onto our backing map */
4052 	if (task_has_sec_restrict_receiving_aliases_to_tagged_memory(task)) {
4053 		vm_map_set_restrict_receiving_aliases_to_tagged_memory(get_task_map(task), true);
4054 	}
4055 
4056 #endif /* HAS_MTE */
4057 
4058 #if HAS_MTE_EMULATION_SHIMS && XNU_TARGET_OS_IOS
4059 	if (task_has_sec(task)) {
4060 		/* Give Rosetta some breathing room for the shadow table. */
4061 		needs_jumbo_va = true;
4062 	}
4063 #endif /* HAS_MTE_EMULATION_SHIMS && XNU_TARGET_OS_IOS */
4064 	if (needs_jumbo_va) {
4065 		vm_map_set_jumbo(get_task_map(task));
4066 	}
4067 
4068 	if (psa && psa->psa_max_addr) {
4069 		vm_map_set_max_addr(get_task_map(task), psa->psa_max_addr, false);
4070 	}
4071 
4072 #if CONFIG_MAP_RANGES
4073 	if ((task_has_hardened_heap(task) ||
4074 	    (task_get_platform_restrictions_version(task) == 1) ||
4075 	    task_get_platform_binary(task)) && !proc_is_simulated(p)) {
4076 		/*
4077 		 * This must be done last as it needs to observe
4078 		 * any kind of VA space growth that was requested.
4079 		 * This is used by the secure allocator, so
4080 		 * must be applied to all platform restrictions binaries
4081 		 */
4082 #if XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT
4083 		needs_extra_jumbo_va = IOTaskHasEntitlement(task,
4084 		    "com.apple.kernel.large-file-virtual-addressing");
4085 #endif /* XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT */
4086 		vm_map_range_configure(get_task_map(task), needs_extra_jumbo_va);
4087 	}
4088 #else
4089 #pragma unused(needs_extra_jumbo_va)
4090 #endif /* CONFIG_MAP_RANGES */
4091 
4092 #if CONFIG_MACF
4093 	if (jit_entitled) {
4094 		vm_map_set_jit_entitled(get_task_map(task));
4095 
4096 	}
4097 #endif /* CONFIG_MACF */
4098 
4099 #if XNU_TARGET_OS_OSX
4100 	/* TPRO cannot be enforced on binaries that load 3P plugins on macos - rdar://107420220 */
4101 	const bool task_loads_3P_plugins = imgp->ip_flags & IMGPF_3P_PLUGINS;
4102 #endif /* XNU_TARGET_OS_OSX */
4103 
4104 	if (task_has_tpro(task)
4105 #if XNU_TARGET_OS_OSX
4106 	    && !task_loads_3P_plugins
4107 #endif /* XNU_TARGET_OS_OSX */
4108 	    ) {
4109 		/*
4110 		 * Pre-emptively disable TPRO remapping for
4111 		 * platform restrictions binaries (which do not load 3P plugins)
4112 		 */
4113 		vm_map_set_tpro_enforcement(get_task_map(task));
4114 	}
4115 }
4116 
4117 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)4118 spawn_posix_cred_adopt(proc_t p,
4119     struct _posix_spawn_posix_cred_info *px_pcred_info)
4120 {
4121 	int error = 0;
4122 
4123 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
4124 		struct setgid_args args = {
4125 			.gid = px_pcred_info->pspci_gid,
4126 		};
4127 		error = setgid(p, &args, NULL);
4128 		if (error) {
4129 			return error;
4130 		}
4131 	}
4132 
4133 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
4134 		error = setgroups_internal(p,
4135 		    px_pcred_info->pspci_ngroups,
4136 		    px_pcred_info->pspci_groups,
4137 		    px_pcred_info->pspci_gmuid);
4138 		if (error) {
4139 			return error;
4140 		}
4141 	}
4142 
4143 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
4144 		struct setuid_args args = {
4145 			.uid = px_pcred_info->pspci_uid,
4146 		};
4147 		error = setuid(p, &args, NULL);
4148 		if (error) {
4149 			return error;
4150 		}
4151 	}
4152 	return 0;
4153 }
4154 
4155 /*
4156  * posix_spawn
4157  *
4158  * Parameters:	uap->pid		Pointer to pid return area
4159  *		uap->fname		File name to exec
4160  *		uap->argp		Argument list
4161  *		uap->envp		Environment list
4162  *
4163  * Returns:	0			Success
4164  *		EINVAL			Invalid argument
4165  *		ENOTSUP			Not supported
4166  *		ENOEXEC			Executable file format error
4167  *	exec_activate_image:EINVAL	Invalid argument
4168  *	exec_activate_image:EACCES	Permission denied
4169  *	exec_activate_image:EINTR	Interrupted function
4170  *	exec_activate_image:ENOMEM	Not enough space
4171  *	exec_activate_image:EFAULT	Bad address
4172  *	exec_activate_image:ENAMETOOLONG	Filename too long
4173  *	exec_activate_image:ENOEXEC	Executable file format error
4174  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
4175  *	exec_activate_image:EAUTH	Image decryption failed
4176  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
4177  *	exec_activate_image:???
4178  *	mac_execve_enter:???
4179  *
4180  * TODO:	Expect to need __mac_posix_spawn() at some point...
4181  *		Handle posix_spawnattr_t
4182  *		Handle posix_spawn_file_actions_t
4183  */
4184 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)4185 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
4186 {
4187 	proc_t p = ap;
4188 	user_addr_t pid = uap->pid;
4189 	int ival[2];            /* dummy retval for setpgid() */
4190 	char *subsystem_root_path = NULL;
4191 	struct image_params *imgp = NULL;
4192 	struct vnode_attr *vap = NULL;
4193 	struct vnode_attr *origvap = NULL;
4194 	struct uthread  *uthread = 0;   /* compiler complains if not set to 0*/
4195 	int error, sig;
4196 	int is_64 = IS_64BIT_PROCESS(p);
4197 	struct vfs_context context;
4198 	struct user__posix_spawn_args_desc px_args = {};
4199 	struct _posix_spawnattr px_sa = {};
4200 	_posix_spawn_file_actions_t px_sfap = NULL;
4201 	_posix_spawn_port_actions_t px_spap = NULL;
4202 	struct __kern_sigaction vec;
4203 	boolean_t spawn_no_exec = FALSE;
4204 	boolean_t proc_transit_set = TRUE;
4205 	boolean_t proc_signal_set = TRUE;
4206 	boolean_t exec_done = FALSE;
4207 	os_reason_t exec_failure_reason = NULL;
4208 
4209 	struct exec_port_actions port_actions = { };
4210 	vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
4211 	task_t old_task = current_task();
4212 	task_t new_task = NULL;
4213 	boolean_t should_release_proc_ref = FALSE;
4214 	void *inherit = NULL;
4215 	uint8_t crash_behavior = 0;
4216 	uint64_t crash_behavior_deadline = 0;
4217 #if CONFIG_EXCLAVES
4218 	char *task_conclave_id = NULL;
4219 #endif
4220 #if CONFIG_PERSONAS
4221 	struct _posix_spawn_persona_info *px_persona = NULL;
4222 #endif
4223 	struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
4224 	struct {
4225 		struct image_params imgp;
4226 		struct vnode_attr va;
4227 		struct vnode_attr origva;
4228 	} *__spawn_data;
4229 
4230 	/*
4231 	 * Allocate a big chunk for locals instead of using stack since these
4232 	 * structures are pretty big.
4233 	 */
4234 	__spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
4235 	if (__spawn_data == NULL) {
4236 		error = ENOMEM;
4237 		goto bad;
4238 	}
4239 	imgp = &__spawn_data->imgp;
4240 	vap = &__spawn_data->va;
4241 	origvap = &__spawn_data->origva;
4242 
4243 	/* Initialize the common data in the image_params structure */
4244 	imgp->ip_user_fname = uap->path;
4245 	imgp->ip_user_argv = uap->argv;
4246 	imgp->ip_user_envv = uap->envp;
4247 	imgp->ip_vattr = vap;
4248 	imgp->ip_origvattr = origvap;
4249 	imgp->ip_vfs_context = &context;
4250 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
4251 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
4252 	imgp->ip_mac_return = 0;
4253 	imgp->ip_px_persona = NULL;
4254 	imgp->ip_px_pcred_info = NULL;
4255 	imgp->ip_cs_error = OS_REASON_NULL;
4256 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
4257 	imgp->ip_subsystem_root_path = NULL;
4258 	imgp->ip_inherited_shared_region_id = NULL;
4259 	imgp->ip_inherited_jop_pid = 0;
4260 	uthread_set_exec_data(current_uthread(), imgp);
4261 
4262 	if (uap->adesc != USER_ADDR_NULL) {
4263 		if (is_64) {
4264 			error = copyin(uap->adesc, &px_args, sizeof(px_args));
4265 		} else {
4266 			struct user32__posix_spawn_args_desc px_args32;
4267 
4268 			error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
4269 
4270 			/*
4271 			 * Convert arguments descriptor from external 32 bit
4272 			 * representation to internal 64 bit representation
4273 			 */
4274 			px_args.attr_size = px_args32.attr_size;
4275 			px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
4276 			px_args.file_actions_size = px_args32.file_actions_size;
4277 			px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
4278 			px_args.port_actions_size = px_args32.port_actions_size;
4279 			px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
4280 			px_args.mac_extensions_size = px_args32.mac_extensions_size;
4281 			px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
4282 			px_args.coal_info_size = px_args32.coal_info_size;
4283 			px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
4284 			px_args.persona_info_size = px_args32.persona_info_size;
4285 			px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
4286 			px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
4287 			px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
4288 			px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
4289 			px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
4290 			px_args.conclave_id_size = px_args32.conclave_id_size;
4291 			px_args.conclave_id = CAST_USER_ADDR_T(px_args32.conclave_id);
4292 		}
4293 		if (error) {
4294 			goto bad;
4295 		}
4296 
4297 		if (px_args.attr_size != 0) {
4298 			/*
4299 			 * We are not copying the port_actions pointer,
4300 			 * because we already have it from px_args.
4301 			 * This is a bit fragile: <rdar://problem/16427422>
4302 			 */
4303 
4304 			if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
4305 				goto bad;
4306 			}
4307 
4308 			imgp->ip_px_sa = &px_sa;
4309 		}
4310 		if (px_args.file_actions_size != 0) {
4311 			/* Limit file_actions to allowed number of open files */
4312 			size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
4313 
4314 			if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
4315 			    maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
4316 				error = EINVAL;
4317 				goto bad;
4318 			}
4319 
4320 			px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
4321 			if (px_sfap == NULL) {
4322 				error = ENOMEM;
4323 				goto bad;
4324 			}
4325 			imgp->ip_px_sfa = px_sfap;
4326 
4327 			if ((error = copyin(px_args.file_actions, px_sfap,
4328 			    px_args.file_actions_size)) != 0) {
4329 				goto bad;
4330 			}
4331 
4332 			/* Verify that the action count matches the struct size */
4333 			size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
4334 			if (psfsize == 0 || psfsize != px_args.file_actions_size) {
4335 				error = EINVAL;
4336 				goto bad;
4337 			}
4338 		}
4339 		if (px_args.port_actions_size != 0) {
4340 			/* Limit port_actions to one page of data */
4341 			if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
4342 			    px_args.port_actions_size > PAGE_SIZE) {
4343 				error = EINVAL;
4344 				goto bad;
4345 			}
4346 
4347 			px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
4348 			if (px_spap == NULL) {
4349 				error = ENOMEM;
4350 				goto bad;
4351 			}
4352 			imgp->ip_px_spa = px_spap;
4353 
4354 			if ((error = copyin(px_args.port_actions, px_spap,
4355 			    px_args.port_actions_size)) != 0) {
4356 				goto bad;
4357 			}
4358 
4359 			/* Verify that the action count matches the struct size */
4360 			size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
4361 			if (pasize == 0 || pasize != px_args.port_actions_size) {
4362 				error = EINVAL;
4363 				goto bad;
4364 			}
4365 		}
4366 #if CONFIG_PERSONAS
4367 		/* copy in the persona info */
4368 		if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
4369 			/* for now, we need the exact same struct in user space */
4370 			if (px_args.persona_info_size != sizeof(*px_persona)) {
4371 				error = ERANGE;
4372 				goto bad;
4373 			}
4374 
4375 			px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
4376 			if (px_persona == NULL) {
4377 				error = ENOMEM;
4378 				goto bad;
4379 			}
4380 			imgp->ip_px_persona = px_persona;
4381 
4382 			if ((error = copyin(px_args.persona_info, px_persona,
4383 			    px_args.persona_info_size)) != 0) {
4384 				goto bad;
4385 			}
4386 			if ((error = spawn_validate_persona(px_persona)) != 0) {
4387 				goto bad;
4388 			}
4389 		}
4390 #endif
4391 		/* copy in the posix cred info */
4392 		if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
4393 			/* for now, we need the exact same struct in user space */
4394 			if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
4395 				error = ERANGE;
4396 				goto bad;
4397 			}
4398 
4399 			if (!kauth_cred_issuser(kauth_cred_get())) {
4400 				error = EPERM;
4401 				goto bad;
4402 			}
4403 
4404 			px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
4405 			if (px_pcred_info == NULL) {
4406 				error = ENOMEM;
4407 				goto bad;
4408 			}
4409 			imgp->ip_px_pcred_info = px_pcred_info;
4410 
4411 			if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
4412 			    px_args.posix_cred_info_size)) != 0) {
4413 				goto bad;
4414 			}
4415 
4416 			if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
4417 				if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
4418 					error = EINVAL;
4419 					goto bad;
4420 				}
4421 			}
4422 		}
4423 #if CONFIG_MACF
4424 		if (px_args.mac_extensions_size != 0) {
4425 			if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
4426 				goto bad;
4427 			}
4428 		}
4429 #endif /* CONFIG_MACF */
4430 		if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
4431 			/*
4432 			 * If a valid-looking subsystem root has been
4433 			 * specified...
4434 			 */
4435 			if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
4436 				/*
4437 				 * ...AND the parent has the entitlement, copy
4438 				 * the subsystem root path in.
4439 				 */
4440 				subsystem_root_path = zalloc_flags(ZV_NAMEI,
4441 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
4442 
4443 				if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
4444 					goto bad;
4445 				}
4446 
4447 				/* Paranoia */
4448 				subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
4449 			}
4450 		}
4451 #if CONFIG_EXCLAVES
4452 
4453 		/*
4454 		 * Calling exclaves_boot_wait() ensures that the conclave name
4455 		 * id will only be set when exclaves are actually
4456 		 * supported/enabled. In practice this will never actually block
4457 		 * as by the time this is called the system will have booted to
4458 		 * EXCLAVECORE if it's supported/enabled.
4459 		 */
4460 		if ((px_args.conclave_id_size > 0) && (px_args.conclave_id_size <= MAXCONCLAVENAME) &&
4461 		    (exclaves_boot_wait(EXCLAVES_BOOT_STAGE_EXCLAVECORE) == KERN_SUCCESS)) {
4462 			if (px_args.conclave_id) {
4463 				if (imgp->ip_px_sa != NULL && (px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
4464 					/* Conclave id could be set only for true spawn */
4465 					error = EINVAL;
4466 					goto bad;
4467 				}
4468 				task_conclave_id = kalloc_data(MAXCONCLAVENAME,
4469 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
4470 				if ((error = copyin(px_args.conclave_id, task_conclave_id, MAXCONCLAVENAME))) {
4471 					goto bad;
4472 				}
4473 				task_conclave_id[MAXCONCLAVENAME - 1] = 0;
4474 			}
4475 		}
4476 #endif
4477 	}
4478 
4479 	if (IOTaskHasEntitlement(old_task, SPAWN_SET_PANIC_CRASH_BEHAVIOR)) {
4480 		/* Truncate to uint8_t since we only support 2 flags for now */
4481 		crash_behavior = (uint8_t)px_sa.psa_crash_behavior;
4482 		crash_behavior_deadline = px_sa.psa_crash_behavior_deadline;
4483 	}
4484 
4485 	/* set uthread to parent */
4486 	uthread = current_uthread();
4487 
4488 	/*
4489 	 * <rdar://6640530>; this does not result in a behaviour change
4490 	 * relative to Leopard, so there should not be any existing code
4491 	 * which depends on it.
4492 	 */
4493 
4494 	if (imgp->ip_px_sa != NULL) {
4495 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4496 		if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
4497 			imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
4498 		}
4499 
4500 #if (DEVELOPMENT || DEBUG)
4501 		if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
4502 			imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
4503 		}
4504 #if HAS_MTE_EMULATION_SHIMS
4505 		/* If the task has inheritance enabled, carry the emulation setup. */
4506 		if (task_has_sec(old_task) && task_has_sec_inherit(old_task)) {
4507 			imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
4508 		}
4509 #endif /* HAS_MTE_EMULATION_SHIMS */
4510 #endif /* (DEVELOPMENT || DEBUG) */
4511 
4512 
4513 		if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
4514 			goto bad;
4515 		}
4516 	}
4517 
4518 	/*
4519 	 * If we don't have the extension flag that turns "posix_spawn()"
4520 	 * into "execve() with options", then we will be creating a new
4521 	 * process which does not inherit memory from the parent process,
4522 	 * which is one of the most expensive things about using fork()
4523 	 * and execve().
4524 	 */
4525 	if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
4526 		/* Set the new task's coalition, if it is requested.  */
4527 		coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
4528 #if CONFIG_COALITIONS
4529 		int i, ncoals;
4530 		kern_return_t kr = KERN_SUCCESS;
4531 		struct _posix_spawn_coalition_info coal_info;
4532 		int coal_role[COALITION_NUM_TYPES];
4533 
4534 		if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
4535 			goto do_fork1;
4536 		}
4537 
4538 		memset(&coal_info, 0, sizeof(coal_info));
4539 
4540 		if (px_args.coal_info_size > sizeof(coal_info)) {
4541 			px_args.coal_info_size = sizeof(coal_info);
4542 		}
4543 		error = copyin(px_args.coal_info,
4544 		    &coal_info, px_args.coal_info_size);
4545 		if (error != 0) {
4546 			goto bad;
4547 		}
4548 
4549 		ncoals = 0;
4550 		for (i = 0; i < COALITION_NUM_TYPES; i++) {
4551 			uint64_t cid = coal_info.psci_info[i].psci_id;
4552 			if (cid != 0) {
4553 				/*
4554 				 * don't allow tasks which are not in a
4555 				 * privileged coalition to spawn processes
4556 				 * into coalitions other than their own
4557 				 */
4558 				if (!task_is_in_privileged_coalition(proc_task(p), i) &&
4559 				    !IOTaskHasEntitlement(proc_task(p), COALITION_SPAWN_ENTITLEMENT)) {
4560 					coal_dbg("ERROR: %d not in privilegd "
4561 					    "coalition of type %d",
4562 					    proc_getpid(p), i);
4563 					spawn_coalitions_release_all(coal);
4564 					error = EPERM;
4565 					goto bad;
4566 				}
4567 
4568 				coal_dbg("searching for coalition id:%llu", cid);
4569 				/*
4570 				 * take a reference and activation on the
4571 				 * coalition to guard against free-while-spawn
4572 				 * races
4573 				 */
4574 				coal[i] = coalition_find_and_activate_by_id(cid);
4575 				if (coal[i] == COALITION_NULL) {
4576 					coal_dbg("could not find coalition id:%llu "
4577 					    "(perhaps it has been terminated or reaped)", cid);
4578 					/*
4579 					 * release any other coalition's we
4580 					 * may have a reference to
4581 					 */
4582 					spawn_coalitions_release_all(coal);
4583 					error = ESRCH;
4584 					goto bad;
4585 				}
4586 				if (coalition_type(coal[i]) != i) {
4587 					coal_dbg("coalition with id:%lld is not of type:%d"
4588 					    " (it's type:%d)", cid, i, coalition_type(coal[i]));
4589 					spawn_coalitions_release_all(coal);
4590 					error = ESRCH;
4591 					goto bad;
4592 				}
4593 				coal_role[i] = coal_info.psci_info[i].psci_role;
4594 				ncoals++;
4595 			}
4596 		}
4597 		if (ncoals < COALITION_NUM_TYPES) {
4598 			/*
4599 			 * If the user is attempting to spawn into a subset of
4600 			 * the known coalition types, then make sure they have
4601 			 * _at_least_ specified a resource coalition. If not,
4602 			 * the following fork1() call will implicitly force an
4603 			 * inheritance from 'p' and won't actually spawn the
4604 			 * new task into the coalitions the user specified.
4605 			 * (also the call to coalitions_set_roles will panic)
4606 			 */
4607 			if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
4608 				spawn_coalitions_release_all(coal);
4609 				error = EINVAL;
4610 				goto bad;
4611 			}
4612 		}
4613 do_fork1:
4614 #endif /* CONFIG_COALITIONS */
4615 
4616 		/*
4617 		 * note that this will implicitly inherit the
4618 		 * caller's persona (if it exists)
4619 		 */
4620 		error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
4621 		/* returns a thread and task reference */
4622 
4623 		if (error == 0) {
4624 			new_task = get_threadtask(imgp->ip_new_thread);
4625 		}
4626 #if CONFIG_COALITIONS
4627 		/* set the roles of this task within each given coalition */
4628 		if (error == 0) {
4629 			kr = coalitions_set_roles(coal, new_task, coal_role);
4630 			if (kr != KERN_SUCCESS) {
4631 				error = EINVAL;
4632 			}
4633 			if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
4634 			    MACH_COALITION_ADOPT))) {
4635 				for (i = 0; i < COALITION_NUM_TYPES; i++) {
4636 					if (coal[i] != COALITION_NULL) {
4637 						/*
4638 						 * On 32-bit targets, uniqueid
4639 						 * will get truncated to 32 bits
4640 						 */
4641 						KDBG_RELEASE(MACHDBG_CODE(
4642 							    DBG_MACH_COALITION,
4643 							    MACH_COALITION_ADOPT),
4644 						    coalition_id(coal[i]),
4645 						    get_task_uniqueid(new_task));
4646 					}
4647 				}
4648 			}
4649 		}
4650 
4651 		/* drop our references and activations - fork1() now holds them */
4652 		spawn_coalitions_release_all(coal);
4653 #endif /* CONFIG_COALITIONS */
4654 		if (error != 0) {
4655 			goto bad;
4656 		}
4657 		imgp->ip_flags |= IMGPF_SPAWN;  /* spawn w/o exec */
4658 		spawn_no_exec = TRUE;           /* used in later tests */
4659 	} else {
4660 		/* Adjust the user proc count */
4661 		(void)chgproccnt(kauth_getruid(), 1);
4662 		/*
4663 		 * For execve case, create a new proc, task and thread
4664 		 * but don't make the proc visible to userland. After
4665 		 * image activation, the new proc would take place of
4666 		 * the old proc in pid hash and other lists that make
4667 		 * the proc visible to the system.
4668 		 */
4669 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
4670 
4671 		/* task and thread ref returned by cloneproc */
4672 		if (imgp->ip_new_thread == NULL) {
4673 			(void)chgproccnt(kauth_getruid(), -1);
4674 			error = ENOMEM;
4675 			goto bad;
4676 		}
4677 
4678 		new_task = get_threadtask(imgp->ip_new_thread);
4679 		imgp->ip_flags |= IMGPF_EXEC;
4680 	}
4681 
4682 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
4683 
4684 	if (spawn_no_exec) {
4685 		/*
4686 		 * We had to wait until this point before firing the
4687 		 * proc:::create probe, otherwise p would not point to the
4688 		 * child process.
4689 		 */
4690 		DTRACE_PROC1(create, proc_t, p);
4691 	}
4692 	assert(p != NULL);
4693 
4694 	if (subsystem_root_path) {
4695 		/* If a subsystem root was specified, swap it in */
4696 		char * old_subsystem_root_path = p->p_subsystem_root_path;
4697 		p->p_subsystem_root_path = subsystem_root_path;
4698 		subsystem_root_path = old_subsystem_root_path;
4699 	}
4700 
4701 	p->p_crash_behavior = crash_behavior;
4702 	p->p_crash_behavior_deadline = crash_behavior_deadline;
4703 
4704 	p->p_crash_count = px_sa.psa_crash_count;
4705 	p->p_throttle_timeout = px_sa.psa_throttle_timeout;
4706 
4707 	/* We'll need the subsystem root for setting up Apple strings */
4708 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4709 
4710 	context.vc_thread = imgp->ip_new_thread;
4711 	context.vc_ucred = proc_ucred_unsafe(p);  /* in init */
4712 
4713 	/*
4714 	 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
4715 	 * to handle the file_actions.
4716 	 */
4717 
4718 	/* Has spawn file actions? */
4719 	if (imgp->ip_px_sfa != NULL) {
4720 		/*
4721 		 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
4722 		 * is handled in exec_handle_file_actions().
4723 		 */
4724 #if CONFIG_AUDIT
4725 		/*
4726 		 * The file actions auditing can overwrite the upath of
4727 		 * AUE_POSIX_SPAWN audit record.  Save the audit record.
4728 		 */
4729 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4730 		uthread->uu_ar = NULL;
4731 #endif
4732 		error = exec_handle_file_actions(imgp,
4733 		    imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
4734 #if CONFIG_AUDIT
4735 		/* Restore the AUE_POSIX_SPAWN audit record. */
4736 		uthread->uu_ar = save_uu_ar;
4737 #endif
4738 		if (error != 0) {
4739 			goto bad;
4740 		}
4741 	}
4742 
4743 	/* Has spawn port actions? */
4744 	if (imgp->ip_px_spa != NULL) {
4745 #if CONFIG_AUDIT
4746 		/*
4747 		 * Do the same for the port actions as we did for the file
4748 		 * actions.  Save the AUE_POSIX_SPAWN audit record.
4749 		 */
4750 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4751 		uthread->uu_ar = NULL;
4752 #endif
4753 		error = exec_handle_port_actions(imgp, &port_actions);
4754 #if CONFIG_AUDIT
4755 		/* Restore the AUE_POSIX_SPAWN audit record. */
4756 		uthread->uu_ar = save_uu_ar;
4757 #endif
4758 		if (error != 0) {
4759 			goto bad;
4760 		}
4761 	}
4762 
4763 	/* Has spawn attr? */
4764 	if (imgp->ip_px_sa != NULL) {
4765 		/*
4766 		 * Reset UID/GID to parent's RUID/RGID; This works only
4767 		 * because the operation occurs before the call
4768 		 * to exec_handle_sugid() by the image activator called
4769 		 * from exec_activate_image().
4770 		 *
4771 		 * POSIX requires that any setuid/setgid bits on the process
4772 		 * image will take precedence over the spawn attributes
4773 		 * (re)setting them.
4774 		 *
4775 		 * Modifications to p_ucred must be guarded using the
4776 		 * proc's ucred lock. This prevents others from accessing
4777 		 * a garbage credential.
4778 		 */
4779 		if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
4780 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
4781 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model){
4782 				return kauth_cred_model_setuidgid(model,
4783 				kauth_cred_getruid(parent),
4784 				kauth_cred_getrgid(parent));
4785 			});
4786 		}
4787 
4788 		if (imgp->ip_px_pcred_info) {
4789 			if (!spawn_no_exec) {
4790 				error = ENOTSUP;
4791 				goto bad;
4792 			}
4793 
4794 			error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
4795 			if (error != 0) {
4796 				goto bad;
4797 			}
4798 		}
4799 
4800 #if CONFIG_PERSONAS
4801 		if (imgp->ip_px_persona != NULL) {
4802 			if (!spawn_no_exec) {
4803 				error = ENOTSUP;
4804 				goto bad;
4805 			}
4806 
4807 			/*
4808 			 * If we were asked to spawn a process into a new persona,
4809 			 * do the credential switch now (which may override the UID/GID
4810 			 * inherit done just above). It's important to do this switch
4811 			 * before image activation both for reasons stated above, and
4812 			 * to ensure that the new persona has access to the image/file
4813 			 * being executed.
4814 			 */
4815 			error = spawn_persona_adopt(p, imgp->ip_px_persona);
4816 			if (error != 0) {
4817 				goto bad;
4818 			}
4819 		}
4820 #endif /* CONFIG_PERSONAS */
4821 #if !SECURE_KERNEL
4822 		/*
4823 		 * Disable ASLR for the spawned process.
4824 		 *
4825 		 * But only do so if we are not embedded + RELEASE.
4826 		 * While embedded allows for a boot-arg (-disable_aslr)
4827 		 * to deal with this (which itself is only honored on
4828 		 * DEVELOPMENT or DEBUG builds of xnu), it is often
4829 		 * useful or necessary to disable ASLR on a per-process
4830 		 * basis for unit testing and debugging.
4831 		 */
4832 		if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
4833 			OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
4834 		}
4835 #endif /* !SECURE_KERNEL */
4836 
4837 		/* Randomize high bits of ASLR slide */
4838 		if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
4839 			imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
4840 		}
4841 
4842 #if !SECURE_KERNEL
4843 		/*
4844 		 * Forcibly disallow execution from data pages for the spawned process
4845 		 * even if it would otherwise be permitted by the architecture default.
4846 		 */
4847 		if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
4848 			imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
4849 		}
4850 #endif /* !SECURE_KERNEL */
4851 
4852 #if     __has_feature(ptrauth_calls)
4853 		if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
4854 			imgp->ip_flags |= IMGPF_RESLIDE;
4855 		}
4856 #endif /* __has_feature(ptrauth_calls) */
4857 
4858 		if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
4859 		    POSIX_SPAWN_PROC_TYPE_DRIVER) {
4860 			imgp->ip_flags |= IMGPF_DRIVER;
4861 		}
4862 	}
4863 
4864 	/*
4865 	 * Disable ASLR during image activation.  This occurs either if the
4866 	 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
4867 	 * P_DISABLE_ASLR was inherited from the parent process.
4868 	 */
4869 	if (p->p_flag & P_DISABLE_ASLR) {
4870 		imgp->ip_flags |= IMGPF_DISABLE_ASLR;
4871 	}
4872 
4873 	/*
4874 	 * Clear transition flag so we won't hang if exec_activate_image() causes
4875 	 * an automount (and launchd does a proc sysctl to service it).
4876 	 *
4877 	 * <rdar://problem/6848672>, <rdar://problem/5959568>.
4878 	 */
4879 	proc_transend(p, 0);
4880 	proc_transit_set = 0;
4881 
4882 	if (!spawn_no_exec) {
4883 		/*
4884 		 * Clear the signal lock in case of exec, since
4885 		 * image activation uses psignal on child process.
4886 		 */
4887 		proc_signalend(p, 0);
4888 		proc_signal_set = 0;
4889 	}
4890 
4891 #if MAC_SPAWN   /* XXX */
4892 	if (uap->mac_p != USER_ADDR_NULL) {
4893 		error = mac_execve_enter(uap->mac_p, imgp);
4894 		if (error) {
4895 			goto bad;
4896 		}
4897 	}
4898 #endif
4899 	/*
4900 	 * Activate the image.
4901 	 * Warning: If activation failed after point of no return, it returns error
4902 	 * as 0 and pretends the call succeeded.
4903 	 */
4904 	error = exec_activate_image(imgp);
4905 #if defined(HAS_APPLE_PAC)
4906 	const uint8_t disable_user_jop = imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE;
4907 	ml_task_set_jop_pid_from_shared_region(new_task, disable_user_jop);
4908 	ml_task_set_disable_user_jop(new_task, disable_user_jop);
4909 	ml_thread_set_disable_user_jop(imgp->ip_new_thread, disable_user_jop);
4910 	ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4911 #endif
4912 
4913 	/*
4914 	 * If you've come here to add support for some new HW feature or some per-process or per-vmmap
4915 	 * or per-pmap flag that needs to be set before the process runs, or are in general lost, here
4916 	 * is some help. This summary was accurate as of Jul 2022. Use git log as needed. This comment
4917 	 * is here to prevent a recurrence of rdar://96307913
4918 	 *
4919 	 * In posix_spawn, following is what happens:
4920 	 * 1. Lots of prep and checking work
4921 	 * 2. Image activation via exec_activate_image(). The new task will get a new pmap here
4922 	 * 3. More prep work. (YOU ARE HERE)
4923 	 * 4. exec_resettextvp() is called
4924 	 * 5. At this point it is safe to check entitlements and code signatures
4925 	 * 6. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4926 	 *    The new thread is allowed to run in kernel. It cannot yet get to userland
4927 	 * 7. More things done here. This is your chance to affect the task before it runs in
4928 	 *    userspace
4929 	 * 8. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4930 	 *     The new thread is allowed to run in userland
4931 	 */
4932 
4933 	if (error == 0 && !spawn_no_exec) {
4934 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
4935 		/* proc ref returned */
4936 		should_release_proc_ref = TRUE;
4937 	}
4938 
4939 	if (error == 0) {
4940 		/* process completed the exec, but may have failed after point of no return */
4941 		exec_done = TRUE;
4942 	}
4943 
4944 #if CONFIG_EXCLAVES
4945 	if (!error && task_conclave_id != NULL) {
4946 		kern_return_t kr;
4947 		kr = task_add_conclave(new_task, imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
4948 		    task_conclave_id);
4949 		if (kr != KERN_SUCCESS) {
4950 			error = EINVAL;
4951 			goto bad;
4952 		}
4953 	}
4954 #endif
4955 
4956 	if (!error && imgp->ip_px_sa != NULL) {
4957 		thread_t child_thread = imgp->ip_new_thread;
4958 		uthread_t child_uthread = get_bsdthread_info(child_thread);
4959 
4960 		/*
4961 		 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
4962 		 * activation, else when image activation fails (before the point of no
4963 		 * return) would leave the parent process in a modified state.
4964 		 */
4965 		if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
4966 			struct setpgid_args spga;
4967 			spga.pid = proc_getpid(p);
4968 			spga.pgid = px_sa.psa_pgroup;
4969 			/*
4970 			 * Effectively, call setpgid() system call; works
4971 			 * because there are no pointer arguments.
4972 			 */
4973 			if ((error = setpgid(p, &spga, ival)) != 0) {
4974 				goto bad_px_sa;
4975 			}
4976 		}
4977 
4978 		if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
4979 			error = setsid_internal(p);
4980 			if (error != 0) {
4981 				goto bad_px_sa;
4982 			}
4983 		}
4984 
4985 		/*
4986 		 * If we have a spawn attr, and it contains signal related flags,
4987 		 * the we need to process them in the "context" of the new child
4988 		 * process, so we have to process it following image activation,
4989 		 * prior to making the thread runnable in user space.  This is
4990 		 * necessitated by some signal information being per-thread rather
4991 		 * than per-process, and we don't have the new allocation in hand
4992 		 * until after the image is activated.
4993 		 */
4994 
4995 		/*
4996 		 * Mask a list of signals, instead of them being unmasked, if
4997 		 * they were unmasked in the parent; note that some signals
4998 		 * are not maskable.
4999 		 */
5000 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
5001 			child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
5002 		}
5003 		/*
5004 		 * Default a list of signals instead of ignoring them, if
5005 		 * they were ignored in the parent.  Note that we pass
5006 		 * spawn_no_exec to setsigvec() to indicate that we called
5007 		 * fork1() and therefore do not need to call proc_signalstart()
5008 		 * internally.
5009 		 */
5010 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
5011 			vec.sa_handler = SIG_DFL;
5012 			vec.sa_tramp = 0;
5013 			vec.sa_mask = 0;
5014 			vec.sa_flags = 0;
5015 			for (sig = 1; sig < NSIG; sig++) {
5016 				if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
5017 					error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
5018 				}
5019 			}
5020 		}
5021 
5022 		/*
5023 		 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
5024 		 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
5025 		 * limit.
5026 		 *
5027 		 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
5028 		 */
5029 		if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
5030 			/*
5031 			 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
5032 			 * an entitlement to configure the monitor a certain way seems silly, since
5033 			 * whomever is turning it on could just as easily choose not to do so.
5034 			 */
5035 			error = proc_set_task_ruse_cpu(proc_task(p),
5036 			    TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
5037 			    (uint8_t)px_sa.psa_cpumonitor_percent,
5038 			    px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
5039 			    0, TRUE);
5040 		}
5041 
5042 
5043 		if (px_pcred_info &&
5044 		    (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
5045 			/*
5046 			 * setlogin() must happen after setsid()
5047 			 */
5048 			setlogin_internal(p, px_pcred_info->pspci_login);
5049 		}
5050 
5051 bad_px_sa:
5052 		if (error != 0) {
5053 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
5054 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR, 0, 0);
5055 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR);
5056 		}
5057 	}
5058 
5059 bad:
5060 
5061 	if (error == 0) {
5062 		/* reset delay idle sleep status if set */
5063 #if CONFIG_DELAY_IDLE_SLEEP
5064 		if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
5065 			OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
5066 		}
5067 #endif /* CONFIG_DELAY_IDLE_SLEEP */
5068 		/* upon  successful spawn, re/set the proc control state */
5069 		if (imgp->ip_px_sa != NULL) {
5070 			switch (px_sa.psa_pcontrol) {
5071 			case POSIX_SPAWN_PCONTROL_THROTTLE:
5072 				p->p_pcaction = P_PCTHROTTLE;
5073 				break;
5074 			case POSIX_SPAWN_PCONTROL_SUSPEND:
5075 				p->p_pcaction = P_PCSUSP;
5076 				break;
5077 			case POSIX_SPAWN_PCONTROL_KILL:
5078 				p->p_pcaction = P_PCKILL;
5079 				break;
5080 			case POSIX_SPAWN_PCONTROL_NONE:
5081 			default:
5082 				p->p_pcaction = 0;
5083 				break;
5084 			}
5085 			;
5086 		}
5087 		exec_resettextvp(p, imgp);
5088 
5089 		vm_map_setup(get_task_map(new_task), new_task);
5090 
5091 		exec_setup_platform_restrictions(new_task);
5092 
5093 		/*
5094 		 * Set starting EXC_GUARD behavior for task now that platform
5095 		 * and platform restrictions bits are set.
5096 		 */
5097 		task_set_exc_guard_default(new_task,
5098 		    proc_best_name(p),
5099 		    strlen(proc_best_name(p)),
5100 		    proc_is_simulated(p),
5101 		    proc_platform(p),
5102 		    proc_sdk(p));
5103 
5104 		/*
5105 		 * Between proc_exec_switch_task and ipc_task_enable, there is a
5106 		 * window where proc_find will return the new proc, but task_for_pid
5107 		 * and similar functions will return an error as the task ipc is not
5108 		 * enabled yet. Configure the task control port during this window
5109 		 * before other process have access to this task port.
5110 		 *
5111 		 * Must enable after resettextvp so that task port policies are not evaluated
5112 		 * until the csblob in the textvp is accurately reflected.
5113 		 */
5114 		task_set_ctrl_port_default(new_task, imgp->ip_new_thread);
5115 
5116 		/*
5117 		 * Enable new task IPC access if exec_activate_image() returned an
5118 		 * active task. (Checks active bit in ipc_task_enable() under lock).
5119 		 * Similarly, this must happen after resettextvp.
5120 		 */
5121 		ipc_task_enable(new_task);
5122 
5123 		/* Set task exception ports now that we can check entitlements */
5124 		if (imgp->ip_px_spa != NULL) {
5125 			error = exec_handle_exception_port_actions(imgp, &port_actions);
5126 		}
5127 
5128 #if CONFIG_MEMORYSTATUS
5129 		/* Set jetsam priority for DriverKit processes */
5130 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
5131 			px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
5132 		}
5133 
5134 		/* Has jetsam attributes? */
5135 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
5136 			int32_t memlimit_active = px_sa.psa_memlimit_active;
5137 			int32_t memlimit_inactive = px_sa.psa_memlimit_inactive;
5138 
5139 			memstat_priority_options_t priority_options = MEMSTAT_PRIORITY_OPTIONS_NONE;
5140 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY)) {
5141 				priority_options |= MEMSTAT_PRIORITY_IS_EFFECTIVE;
5142 			}
5143 			memorystatus_set_priority(p, px_sa.psa_priority, 0,
5144 			    priority_options);
5145 
5146 			memlimit_options_t memlimit_options = MEMLIMIT_OPTIONS_NONE;
5147 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL)) {
5148 				memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
5149 			}
5150 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL)) {
5151 				memlimit_options |= MEMLIMIT_INACTIVE_FATAL;
5152 			}
5153 			if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
5154 				/*
5155 				 * With 2-level high-water-mark support,
5156 				 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no longer relevant,
5157 				 * as background limits are described via the inactive limit
5158 				 * slots. However, if the
5159 				 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in, we
5160 				 * attempt to mimic previous behavior by forcing the BG limit
5161 				 * data into the inactive/non-fatal mode and force the active
5162 				 * slots to hold system_wide/fatal mode.
5163 				 */
5164 				memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
5165 				memlimit_options &= ~MEMLIMIT_INACTIVE_FATAL;
5166 				memlimit_active = -1;
5167 			}
5168 			memorystatus_set_memlimits(p, memlimit_active, memlimit_inactive,
5169 			    memlimit_options);
5170 		}
5171 
5172 		/* Has jetsam relaunch behavior? */
5173 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
5174 			/*
5175 			 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
5176 			 * This data would be used by the jetsam subsystem to determine the position and protection
5177 			 * offered to this process on dirty -> clean transitions.
5178 			 */
5179 			int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
5180 			switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
5181 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
5182 				relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
5183 				break;
5184 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
5185 				relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
5186 				break;
5187 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
5188 				relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
5189 				break;
5190 			default:
5191 				break;
5192 			}
5193 			memorystatus_relaunch_flags_update(p, relaunch_flags);
5194 		}
5195 
5196 #endif /* CONFIG_MEMORYSTATUS */
5197 		if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
5198 			task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
5199 		}
5200 		if (imgp->ip_px_sa != NULL && px_sa.psa_conclave_mem_limit > 0) {
5201 			task_set_conclave_mem_limit(new_task, px_sa.psa_conclave_mem_limit);
5202 		}
5203 
5204 #if CONFIG_PROC_RESOURCE_LIMITS
5205 		if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
5206 			task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
5207 			    (uint32_t)px_sa.psa_port_hard_limit);
5208 		}
5209 
5210 		if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
5211 			proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
5212 			    (int)px_sa.psa_filedesc_hard_limit);
5213 		}
5214 		if (imgp->ip_px_sa != NULL && (px_sa.psa_kqworkloop_soft_limit > 0 || px_sa.psa_kqworkloop_hard_limit > 0)) {
5215 			proc_set_kqworkloop_limits(p, (int)px_sa.psa_kqworkloop_soft_limit,
5216 			    (int)px_sa.psa_kqworkloop_hard_limit);
5217 		}
5218 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
5219 
5220 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_REALTIME_AUDIO)) {
5221 			task_set_jetsam_realtime_audio(new_task, TRUE);
5222 		}
5223 	}
5224 
5225 
5226 	/*
5227 	 * If we successfully called fork1() or cloneproc, we always need
5228 	 * to do this. This is because we come back from that call with
5229 	 * signals blocked in the child, and we have to unblock them, for exec
5230 	 * case they are unblocked before activation, but for true spawn case
5231 	 * we want to wait until after we've performed any spawn actions.
5232 	 * This has to happen before process_signature(), which uses psignal.
5233 	 */
5234 	if (proc_transit_set) {
5235 		proc_transend(p, 0);
5236 	}
5237 
5238 	/*
5239 	 * Drop the signal lock on the child which was taken on our
5240 	 * behalf by forkproc()/cloneproc() to prevent signals being
5241 	 * received by the child in a partially constructed state.
5242 	 */
5243 	if (proc_signal_set) {
5244 		proc_signalend(p, 0);
5245 	}
5246 
5247 	if (error == 0) {
5248 		/*
5249 		 * We need to initialize the bank context behind the protection of
5250 		 * the proc_trans lock to prevent a race with exit. We can't do this during
5251 		 * exec_activate_image because task_bank_init checks entitlements that
5252 		 * aren't loaded until subsequent calls (including exec_resettextvp).
5253 		 */
5254 		error = proc_transstart(p, 0, 0);
5255 
5256 		if (error == 0) {
5257 			task_bank_init(new_task);
5258 			proc_transend(p, 0);
5259 		}
5260 
5261 #if __arm64__
5262 		proc_footprint_entitlement_hacks(p, new_task);
5263 #endif /* __arm64__ */
5264 
5265 #if XNU_TARGET_OS_OSX
5266 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
5267 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
5268 			vm_map_single_jit(get_task_map(new_task));
5269 		}
5270 #endif /* XNU_TARGET_OS_OSX */
5271 
5272 #if __has_feature(ptrauth_calls)
5273 		task_set_pac_exception_fatal_flag(new_task);
5274 #endif /* __has_feature(ptrauth_calls) */
5275 		task_set_jit_flags(new_task);
5276 	}
5277 
5278 	/* Inherit task role from old task to new task for exec */
5279 	if (error == 0 && !spawn_no_exec) {
5280 		proc_inherit_task_role(new_task, old_task);
5281 	}
5282 
5283 #if CONFIG_ARCADE
5284 	if (error == 0) {
5285 		/*
5286 		 * Check to see if we need to trigger an arcade upcall AST now
5287 		 * that the vnode has been reset on the task.
5288 		 */
5289 		arcade_prepare(new_task, imgp->ip_new_thread);
5290 	}
5291 #endif /* CONFIG_ARCADE */
5292 
5293 	if (error == 0) {
5294 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
5295 	}
5296 
5297 	/* Clear the initial wait on the thread before handling spawn policy */
5298 	if (imgp && imgp->ip_new_thread) {
5299 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
5300 	}
5301 
5302 	/*
5303 	 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
5304 	 * and bind any portwatch ports to the new task.
5305 	 * This must be done after the exec so that the child's thread is ready,
5306 	 * and after the in transit state has been released, because priority is
5307 	 * dropped here so we need to be prepared for a potentially long preemption interval
5308 	 *
5309 	 * TODO: Consider splitting this up into separate phases
5310 	 */
5311 	if (error == 0 && imgp->ip_px_sa != NULL) {
5312 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
5313 
5314 		error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
5315 		    psa->psa_darwin_role, &port_actions);
5316 	}
5317 
5318 	/* Transfer the turnstile watchport boost to new task if in exec */
5319 	if (error == 0 && !spawn_no_exec) {
5320 		task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
5321 	}
5322 
5323 	if (error == 0 && imgp->ip_px_sa != NULL) {
5324 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
5325 
5326 		if (psa->psa_no_smt) {
5327 			task_set_no_smt(new_task);
5328 		}
5329 		if (psa->psa_tecs) {
5330 			task_set_tecs(new_task);
5331 		}
5332 	}
5333 
5334 	struct _iopol_param_t iop_param = {
5335 		.iop_scope = IOPOL_SCOPE_PROCESS,
5336 		.iop_iotype = IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES,
5337 	};
5338 
5339 	if (error == 0) {
5340 		if (imgp->ip_px_sa != NULL) {
5341 			struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
5342 
5343 			if (psa->psa_options & PSA_OPTION_DATALESS_IOPOLICY) {
5344 				iop_param.iop_policy = psa->psa_dataless_iopolicy;
5345 			}
5346 		} else {
5347 			error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_GET, iop_param.iop_scope,
5348 			    iop_param.iop_policy, &iop_param);
5349 		}
5350 	}
5351 
5352 	if (error == 0 && iop_param.iop_policy != 0) {
5353 		error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_SET, iop_param.iop_scope,
5354 		    (iop_param.iop_policy | IOPOL_MATERIALIZE_DATALESS_FILES_ORIG), &iop_param);
5355 	}
5356 
5357 	if (error == 0) {
5358 		/* Apply the main thread qos */
5359 		thread_t main_thread = imgp->ip_new_thread;
5360 		task_set_main_thread_qos(new_task, main_thread);
5361 	}
5362 
5363 	/*
5364 	 * Release any ports we kept around for binding to the new task
5365 	 * We need to release the rights even if the posix_spawn has failed.
5366 	 */
5367 	if (imgp->ip_px_spa != NULL) {
5368 		exec_port_actions_destroy(&port_actions);
5369 	}
5370 
5371 	/*
5372 	 * We have to delay operations which might throw a signal until after
5373 	 * the signals have been unblocked; however, we want that to happen
5374 	 * after exec_resettextvp() so that the textvp is correct when they
5375 	 * fire.
5376 	 */
5377 	if (error == 0) {
5378 		error = process_signature(p, imgp);
5379 
5380 		/*
5381 		 * Pay for our earlier safety; deliver the delayed signals from
5382 		 * the incomplete spawn process now that it's complete.
5383 		 */
5384 		if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
5385 			psignal_vfork(p, proc_task(p), imgp->ip_new_thread, SIGTRAP);
5386 		}
5387 
5388 		if (error == 0 && !spawn_no_exec) {
5389 			extern uint64_t kdp_task_exec_meta_flags(task_t task);
5390 			KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
5391 			    proc_getpid(p), kdp_task_exec_meta_flags(proc_task(p)));
5392 		}
5393 	}
5394 
5395 	if (spawn_no_exec) {
5396 		/* flag the 'fork' has occurred */
5397 		proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
5398 	}
5399 
5400 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
5401 	if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
5402 		proc_knote(p, NOTE_EXEC);
5403 	}
5404 
5405 	if (imgp != NULL) {
5406 		uthread_set_exec_data(current_uthread(), NULL);
5407 		if (imgp->ip_vp) {
5408 			vnode_put(imgp->ip_vp);
5409 		}
5410 		if (imgp->ip_scriptvp) {
5411 			vnode_put(imgp->ip_scriptvp);
5412 		}
5413 		if (imgp->ip_strings) {
5414 			execargs_free(imgp);
5415 		}
5416 		if (imgp->ip_free_map) {
5417 			/* Free the map after dropping iocount on vnode to avoid deadlock */
5418 			vm_map_deallocate(imgp->ip_free_map);
5419 		}
5420 		kfree_data(imgp->ip_px_sfa,
5421 		    px_args.file_actions_size);
5422 		kfree_data(imgp->ip_px_spa,
5423 		    px_args.port_actions_size);
5424 #if CONFIG_PERSONAS
5425 		kfree_data(imgp->ip_px_persona,
5426 		    px_args.persona_info_size);
5427 #endif
5428 		kfree_data(imgp->ip_px_pcred_info,
5429 		    px_args.posix_cred_info_size);
5430 
5431 		if (subsystem_root_path != NULL) {
5432 			zfree(ZV_NAMEI, subsystem_root_path);
5433 		}
5434 #if CONFIG_MACF
5435 		struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
5436 		kfree_data(px_s->array, px_args.mac_extensions_size);
5437 		kfree_data(px_s->data, (vm_size_t)px_s->datalen);
5438 
5439 		if (imgp->ip_execlabelp) {
5440 			mac_cred_label_free(imgp->ip_execlabelp);
5441 			imgp->ip_execlabelp = NULL;
5442 		}
5443 		if (imgp->ip_scriptlabelp) {
5444 			mac_vnode_label_free(imgp->ip_scriptlabelp);
5445 			imgp->ip_scriptlabelp = NULL;
5446 		}
5447 		if (imgp->ip_cs_error != OS_REASON_NULL) {
5448 			os_reason_free(imgp->ip_cs_error);
5449 			imgp->ip_cs_error = OS_REASON_NULL;
5450 		}
5451 		if (imgp->ip_inherited_shared_region_id != NULL) {
5452 			kfree_data(imgp->ip_inherited_shared_region_id,
5453 			    strlen(imgp->ip_inherited_shared_region_id) + 1);
5454 			imgp->ip_inherited_shared_region_id = NULL;
5455 		}
5456 #endif
5457 	}
5458 
5459 #if CONFIG_DTRACE
5460 	if (spawn_no_exec) {
5461 		/*
5462 		 * In the original DTrace reference implementation,
5463 		 * posix_spawn() was a libc routine that just
5464 		 * did vfork(2) then exec(2).  Thus the proc::: probes
5465 		 * are very fork/exec oriented.  The details of this
5466 		 * in-kernel implementation of posix_spawn() is different
5467 		 * (while producing the same process-observable effects)
5468 		 * particularly w.r.t. errors, and which thread/process
5469 		 * is constructing what on behalf of whom.
5470 		 */
5471 		if (error) {
5472 			DTRACE_PROC1(spawn__failure, int, error);
5473 		} else {
5474 			DTRACE_PROC(spawn__success);
5475 			/*
5476 			 * Some DTrace scripts, e.g. newproc.d in
5477 			 * /usr/bin, rely on the the 'exec-success'
5478 			 * probe being fired in the child after the
5479 			 * new process image has been constructed
5480 			 * in order to determine the associated pid.
5481 			 *
5482 			 * So, even though the parent built the image
5483 			 * here, for compatibility, mark the new thread
5484 			 * so 'exec-success' fires on it as it leaves
5485 			 * the kernel.
5486 			 */
5487 			dtrace_thread_didexec(imgp->ip_new_thread);
5488 		}
5489 	} else {
5490 		if (error) {
5491 			DTRACE_PROC1(exec__failure, int, error);
5492 		} else {
5493 			dtrace_thread_didexec(imgp->ip_new_thread);
5494 		}
5495 	}
5496 
5497 	if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5498 		(*dtrace_proc_waitfor_hook)(p);
5499 	}
5500 #endif
5501 
5502 #if CONFIG_AUDIT
5503 	if (!error && AUDIT_ENABLED() && p) {
5504 		/* Add the CDHash of the new process to the audit record */
5505 		uint8_t *cdhash = cs_get_cdhash(p);
5506 		if (cdhash) {
5507 			AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5508 		}
5509 	}
5510 #endif
5511 
5512 	/* terminate the new task if exec failed  */
5513 	if (new_task != NULL && task_is_exec_copy(new_task)) {
5514 		task_terminate_internal(new_task);
5515 	}
5516 
5517 	if (exec_failure_reason && !spawn_no_exec) {
5518 		psignal_with_reason(p, SIGKILL, exec_failure_reason);
5519 		exec_failure_reason = NULL;
5520 	}
5521 
5522 	/* Return to both the parent and the child? */
5523 	if (imgp != NULL && spawn_no_exec) {
5524 		/*
5525 		 * If the parent wants the pid, copy it out
5526 		 */
5527 		if (error == 0 && pid != USER_ADDR_NULL) {
5528 			_Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
5529 			bool aligned = (pid & 3) == 0;
5530 			if (aligned) {
5531 				(void)copyout_atomic32(proc_getpid(p), pid);
5532 			} else {
5533 				(void)suword(pid, proc_getpid(p));
5534 			}
5535 		}
5536 		retval[0] = error;
5537 
5538 		/*
5539 		 * If we had an error, perform an internal reap ; this is
5540 		 * entirely safe, as we have a real process backing us.
5541 		 */
5542 		if (error) {
5543 			proc_list_lock();
5544 			p->p_listflag |= P_LIST_DEADPARENT;
5545 			proc_list_unlock();
5546 			proc_lock(p);
5547 			/* make sure no one else has killed it off... */
5548 			if (p->p_stat != SZOMB && p->exit_thread == NULL) {
5549 				p->exit_thread = current_thread();
5550 				p->p_posix_spawn_failed = true;
5551 				proc_unlock(p);
5552 				exit1(p, 1, (int *)NULL);
5553 			} else {
5554 				/* someone is doing it for us; just skip it */
5555 				proc_unlock(p);
5556 			}
5557 		}
5558 	}
5559 
5560 	/*
5561 	 * Do not terminate the current task, if proc_exec_switch_task did not
5562 	 * switch the tasks, terminating the current task without the switch would
5563 	 * result in loosing the SIGKILL status.
5564 	 */
5565 	if (task_did_exec(old_task)) {
5566 		/* Terminate the current task, since exec will start in new task */
5567 		task_terminate_internal(old_task);
5568 	}
5569 
5570 	/* Release the thread ref returned by cloneproc/fork1 */
5571 	if (imgp != NULL && imgp->ip_new_thread) {
5572 		/* clear the exec complete flag if there is an error before point of no-return */
5573 		uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5574 		if (!spawn_no_exec && !exec_done && error != 0) {
5575 			clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5576 		}
5577 		/* wake up the new thread */
5578 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5579 		thread_deallocate(imgp->ip_new_thread);
5580 		imgp->ip_new_thread = NULL;
5581 	}
5582 
5583 	/* Release the ref returned by cloneproc/fork1 */
5584 	if (new_task) {
5585 		task_deallocate(new_task);
5586 		new_task = NULL;
5587 	}
5588 
5589 	if (should_release_proc_ref) {
5590 		proc_rele(p);
5591 	}
5592 
5593 	kfree_type(typeof(*__spawn_data), __spawn_data);
5594 
5595 	if (inherit != NULL) {
5596 		ipc_importance_release(inherit);
5597 	}
5598 
5599 #if CONFIG_EXCLAVES
5600 	if (task_conclave_id != NULL) {
5601 		kfree_data(task_conclave_id, MAXCONCLAVENAME);
5602 	}
5603 #endif
5604 
5605 	assert(spawn_no_exec || exec_failure_reason == NULL);
5606 	return error;
5607 }
5608 
5609 /*
5610  * proc_exec_switch_task
5611  *
5612  * Parameters:  old_proc		proc before exec
5613  *		new_proc		proc after exec
5614  *		old_task		task before exec
5615  *		new_task		task after exec
5616  *		imgp			image params
5617  *		inherit			resulting importance linkage
5618  *
5619  * Returns: proc.
5620  *
5621  * Note: The function will switch proc in pid hash from old proc to new proc.
5622  * The switch needs to happen after draining all proc refs and inside
5623  * a proc list lock. In the case of failure to switch the proc, which
5624  * might happen if the process received a SIGKILL or jetsam killed it,
5625  * it will make sure that the new tasks terminates. User proc ref returned
5626  * to caller.
5627  *
5628  * This function is called after point of no return, in the case
5629  * failure to switch, it will terminate the new task and swallow the
5630  * error and let the terminated process complete exec and die.
5631  */
5632 proc_t
proc_exec_switch_task(proc_t old_proc,proc_t new_proc,task_t old_task,task_t new_task,struct image_params * imgp,void ** inherit)5633 proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task, task_t new_task, struct image_params *imgp, void **inherit)
5634 {
5635 	boolean_t task_active;
5636 	boolean_t proc_active;
5637 	boolean_t thread_active;
5638 	boolean_t reparent_traced_child = FALSE;
5639 	thread_t old_thread = current_thread();
5640 	thread_t new_thread = imgp->ip_new_thread;
5641 
5642 	thread_set_exec_promotion(old_thread);
5643 	old_proc = proc_refdrain_will_exec(old_proc);
5644 
5645 	new_proc = proc_refdrain_will_exec(new_proc);
5646 	/* extra proc ref returned to the caller */
5647 
5648 	assert(get_threadtask(new_thread) == new_task);
5649 	task_active = task_is_active(new_task);
5650 	proc_active = !(old_proc->p_lflag & P_LEXIT);
5651 
5652 	/* Check if the current thread is not aborted due to SIGKILL */
5653 	thread_active = thread_is_active(old_thread);
5654 
5655 	/*
5656 	 * Do not switch the proc if the new task or proc is already terminated
5657 	 * as a result of error in exec past point of no return
5658 	 */
5659 	if (proc_active && task_active && thread_active) {
5660 		uthread_t new_uthread = get_bsdthread_info(new_thread);
5661 		uthread_t old_uthread = current_uthread();
5662 
5663 		/* Clear dispatchqueue and workloop ast offset */
5664 		new_proc->p_dispatchqueue_offset = 0;
5665 		new_proc->p_dispatchqueue_serialno_offset = 0;
5666 		new_proc->p_dispatchqueue_label_offset = 0;
5667 		new_proc->p_return_to_kernel_offset = 0;
5668 		new_proc->p_pthread_wq_quantum_offset = 0;
5669 
5670 		/* If old_proc is session leader, change the leader to new proc */
5671 		session_replace_leader(old_proc, new_proc);
5672 
5673 		proc_lock(old_proc);
5674 
5675 		/* Copy the signal state, dtrace state and set bsd ast on new thread */
5676 		act_set_astbsd(new_thread);
5677 		new_uthread->uu_siglist |= old_uthread->uu_siglist;
5678 		new_uthread->uu_siglist |= old_proc->p_siglist;
5679 		new_uthread->uu_sigwait = old_uthread->uu_sigwait;
5680 		new_uthread->uu_sigmask = old_uthread->uu_sigmask;
5681 		new_uthread->uu_oldmask = old_uthread->uu_oldmask;
5682 		new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
5683 #if CONFIG_DTRACE
5684 		new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
5685 		new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
5686 		new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
5687 		assert(new_uthread->t_dtrace_scratch == NULL);
5688 		new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
5689 
5690 		old_uthread->t_dtrace_sig = 0;
5691 		old_uthread->t_dtrace_stop = 0;
5692 		old_uthread->t_dtrace_resumepid = 0;
5693 		old_uthread->t_dtrace_scratch = NULL;
5694 #endif
5695 
5696 #if CONFIG_PROC_UDATA_STORAGE
5697 		new_proc->p_user_data = old_proc->p_user_data;
5698 #endif /* CONFIG_PROC_UDATA_STORAGE */
5699 
5700 		/* Copy the resource accounting info */
5701 		thread_copy_resource_info(new_thread, current_thread());
5702 
5703 		/* Clear the exit reason and signal state on old thread */
5704 		old_uthread->uu_exit_reason = NULL;
5705 		old_uthread->uu_siglist = 0;
5706 
5707 		task_set_did_exec_flag(old_task);
5708 		task_clear_exec_copy_flag(new_task);
5709 
5710 		task_copy_fields_for_exec(new_task, old_task);
5711 
5712 		/*
5713 		 * Need to transfer pending watch port boosts to the new task
5714 		 * while still making sure that the old task remains in the
5715 		 * importance linkage. Create an importance linkage from old task
5716 		 * to new task, then switch the task importance base of old task
5717 		 * and new task. After the switch the port watch boost will be
5718 		 * boosting the new task and new task will be donating importance
5719 		 * to old task.
5720 		 */
5721 		*inherit = ipc_importance_exec_switch_task(old_task, new_task);
5722 
5723 		/* Transfer parent's ptrace state to child */
5724 		new_proc->p_lflag &= ~(P_LTRACED | P_LSIGEXC | P_LNOATTACH);
5725 		new_proc->p_lflag |= (old_proc->p_lflag & (P_LTRACED | P_LSIGEXC | P_LNOATTACH));
5726 		new_proc->p_oppid = old_proc->p_oppid;
5727 
5728 		if (old_proc->p_pptr != new_proc->p_pptr) {
5729 			reparent_traced_child = TRUE;
5730 			new_proc->p_lflag |= P_LTRACE_WAIT;
5731 		}
5732 
5733 		proc_unlock(old_proc);
5734 
5735 		/* Update the list of proc knotes */
5736 		proc_transfer_knotes(old_proc, new_proc);
5737 
5738 		/* Update the proc interval timers */
5739 		proc_inherit_itimers(old_proc, new_proc);
5740 
5741 		proc_list_lock();
5742 
5743 		/* Insert the new proc in child list of parent proc */
5744 		p_reparentallchildren(old_proc, new_proc);
5745 
5746 		/* Switch proc in pid hash */
5747 		phash_replace_locked(old_proc, new_proc);
5748 
5749 		/* Transfer the shadow flag to old proc */
5750 		os_atomic_andnot(&new_proc->p_refcount, P_REF_SHADOW, relaxed);
5751 		os_atomic_or(&old_proc->p_refcount, P_REF_SHADOW, relaxed);
5752 
5753 		/* Change init proc if launchd exec */
5754 		if (old_proc == initproc) {
5755 			/* Take the ref on new proc after proc_refwake_did_exec */
5756 			initproc = new_proc;
5757 			/* Drop the proc ref on old proc */
5758 			proc_rele(old_proc);
5759 		}
5760 
5761 		proc_list_unlock();
5762 #if CONFIG_EXCLAVES
5763 		if (task_inherit_conclave(old_task, new_task, imgp->ip_vp,
5764 		    (int64_t)imgp->ip_arch_offset) != KERN_SUCCESS) {
5765 			task_terminate_internal(new_task);
5766 		}
5767 #endif
5768 	} else {
5769 		task_terminate_internal(new_task);
5770 	}
5771 
5772 	proc_refwake_did_exec(new_proc);
5773 	proc_refwake_did_exec(old_proc);
5774 
5775 	/* Take a ref on initproc if it changed */
5776 	if (new_proc == initproc) {
5777 		initproc = proc_ref(new_proc, false);
5778 		assert(initproc != PROC_NULL);
5779 	}
5780 
5781 	thread_clear_exec_promotion(old_thread);
5782 	proc_rele(old_proc);
5783 
5784 	if (reparent_traced_child) {
5785 		proc_t pp = proc_parent(old_proc);
5786 		assert(pp != PROC_NULL);
5787 
5788 		proc_reparentlocked(new_proc, pp, 1, 0);
5789 		proc_rele(pp);
5790 
5791 		proc_lock(new_proc);
5792 		new_proc->p_lflag &= ~P_LTRACE_WAIT;
5793 		proc_unlock(new_proc);
5794 	}
5795 
5796 	return new_proc;
5797 }
5798 
5799 /*
5800  * execve
5801  *
5802  * Parameters:	uap->fname		File name to exec
5803  *		uap->argp		Argument list
5804  *		uap->envp		Environment list
5805  *
5806  * Returns:	0			Success
5807  *	__mac_execve:EINVAL		Invalid argument
5808  *	__mac_execve:ENOTSUP		Invalid argument
5809  *	__mac_execve:EACCES		Permission denied
5810  *	__mac_execve:EINTR		Interrupted function
5811  *	__mac_execve:ENOMEM		Not enough space
5812  *	__mac_execve:EFAULT		Bad address
5813  *	__mac_execve:ENAMETOOLONG	Filename too long
5814  *	__mac_execve:ENOEXEC		Executable file format error
5815  *	__mac_execve:ETXTBSY		Text file busy [misuse of error code]
5816  *	__mac_execve:???
5817  *
5818  * TODO:	Dynamic linker header address on stack is copied via suword()
5819  */
5820 /* ARGSUSED */
5821 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)5822 execve(proc_t p, struct execve_args *uap, int32_t *retval)
5823 {
5824 	struct __mac_execve_args muap;
5825 	int err;
5826 
5827 	memoryshot(DBG_VM_EXECVE, DBG_FUNC_NONE);
5828 
5829 	muap.fname = uap->fname;
5830 	muap.argp = uap->argp;
5831 	muap.envp = uap->envp;
5832 	muap.mac_p = USER_ADDR_NULL;
5833 	err = __mac_execve(p, &muap, retval);
5834 
5835 	return err;
5836 }
5837 
5838 /*
5839  * __mac_execve
5840  *
5841  * Parameters:	uap->fname		File name to exec
5842  *		uap->argp		Argument list
5843  *		uap->envp		Environment list
5844  *		uap->mac_p		MAC label supplied by caller
5845  *
5846  * Returns:	0			Success
5847  *		EINVAL			Invalid argument
5848  *		ENOTSUP			Not supported
5849  *		ENOEXEC			Executable file format error
5850  *	exec_activate_image:EINVAL	Invalid argument
5851  *	exec_activate_image:EACCES	Permission denied
5852  *	exec_activate_image:EINTR	Interrupted function
5853  *	exec_activate_image:ENOMEM	Not enough space
5854  *	exec_activate_image:EFAULT	Bad address
5855  *	exec_activate_image:ENAMETOOLONG	Filename too long
5856  *	exec_activate_image:ENOEXEC	Executable file format error
5857  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
5858  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
5859  *	exec_activate_image:???
5860  *	mac_execve_enter:???
5861  *
5862  * TODO:	Dynamic linker header address on stack is copied via suword()
5863  */
5864 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)5865 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
5866 {
5867 	struct image_params *imgp = NULL;
5868 	struct vnode_attr *vap = NULL;
5869 	struct vnode_attr *origvap = NULL;
5870 	int error;
5871 	int is_64 = IS_64BIT_PROCESS(p);
5872 	struct vfs_context context;
5873 	struct uthread  *uthread = NULL;
5874 	task_t old_task = current_task();
5875 	task_t new_task = NULL;
5876 	boolean_t should_release_proc_ref = FALSE;
5877 	boolean_t exec_done = FALSE;
5878 	void *inherit = NULL;
5879 	struct {
5880 		struct image_params imgp;
5881 		struct vnode_attr va;
5882 		struct vnode_attr origva;
5883 	} *__execve_data;
5884 
5885 	/* Allocate a big chunk for locals instead of using stack since these
5886 	 * structures are pretty big.
5887 	 */
5888 	__execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
5889 	if (__execve_data == NULL) {
5890 		error = ENOMEM;
5891 		goto exit_with_error;
5892 	}
5893 	imgp = &__execve_data->imgp;
5894 	vap = &__execve_data->va;
5895 	origvap = &__execve_data->origva;
5896 
5897 	/* Initialize the common data in the image_params structure */
5898 	imgp->ip_user_fname = uap->fname;
5899 	imgp->ip_user_argv = uap->argp;
5900 	imgp->ip_user_envv = uap->envp;
5901 	imgp->ip_vattr = vap;
5902 	imgp->ip_origvattr = origvap;
5903 	imgp->ip_vfs_context = &context;
5904 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
5905 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
5906 	imgp->ip_mac_return = 0;
5907 	imgp->ip_cs_error = OS_REASON_NULL;
5908 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
5909 	imgp->ip_subsystem_root_path = NULL;
5910 	uthread_set_exec_data(current_uthread(), imgp);
5911 
5912 #if CONFIG_MACF
5913 	if (uap->mac_p != USER_ADDR_NULL) {
5914 		error = mac_execve_enter(uap->mac_p, imgp);
5915 		if (error) {
5916 			goto exit_with_error;
5917 		}
5918 	}
5919 #endif
5920 	uthread = current_uthread();
5921 	{
5922 		imgp->ip_flags |= IMGPF_EXEC;
5923 
5924 		/* Adjust the user proc count */
5925 		(void)chgproccnt(kauth_getruid(), 1);
5926 		/*
5927 		 * For execve case, create a new proc, task and thread
5928 		 * but don't make the proc visible to userland. After
5929 		 * image activation, the new proc would take place of
5930 		 * the old proc in pid hash and other lists that make
5931 		 * the proc visible to the system.
5932 		 */
5933 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
5934 		/* task and thread ref returned by cloneproc */
5935 		if (imgp->ip_new_thread == NULL) {
5936 			(void)chgproccnt(kauth_getruid(), -1);
5937 			error = ENOMEM;
5938 			goto exit_with_error;
5939 		}
5940 
5941 		new_task = get_threadtask(imgp->ip_new_thread);
5942 	}
5943 
5944 #if HAS_MTE_EMULATION_SHIMS
5945 	/*
5946 	 * ARM2ARM Rosetta doesn't carry over the configuration from the initial posix_spawn,
5947 	 * so we key the enablement of the runtime to whether inheritance is enabled or not
5948 	 * for the task. We will defer any MTE specific configuration to image activation.
5949 	 */
5950 	if (task_has_sec_inherit(old_task) && task_has_sec(old_task)) {
5951 		imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
5952 	}
5953 #endif /* HAS_MTE_EMULATION_SHIMS */
5954 
5955 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
5956 
5957 	context.vc_thread = imgp->ip_new_thread;
5958 	context.vc_ucred = kauth_cred_proc_ref(p);      /* XXX must NOT be kauth_cred_get() */
5959 
5960 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
5961 
5962 	proc_transend(p, 0);
5963 	proc_signalend(p, 0);
5964 
5965 	/*
5966 	 * Activate the image.
5967 	 * Warning: If activation failed after point of no return, it returns error
5968 	 * as 0 and pretends the call succeeded.
5969 	 */
5970 	error = exec_activate_image(imgp);
5971 	/* thread and task ref returned for vfexec case */
5972 
5973 	if (imgp->ip_new_thread != NULL) {
5974 		/*
5975 		 * task reference might be returned by exec_activate_image
5976 		 * for vfexec.
5977 		 */
5978 		new_task = get_threadtask(imgp->ip_new_thread);
5979 #if defined(HAS_APPLE_PAC)
5980 		ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5981 		ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5982 #endif
5983 	}
5984 
5985 	if (!error) {
5986 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
5987 		/* proc ref returned */
5988 		should_release_proc_ref = TRUE;
5989 	}
5990 
5991 	kauth_cred_unref(&context.vc_ucred);
5992 
5993 	if (!error) {
5994 		exec_done = TRUE;
5995 		assert(imgp->ip_new_thread != NULL);
5996 
5997 		exec_resettextvp(p, imgp);
5998 
5999 		vm_map_setup(get_task_map(new_task), new_task);
6000 
6001 		exec_setup_platform_restrictions(new_task);
6002 
6003 		/*
6004 		 * Set starting EXC_GUARD behavior for task now that platform
6005 		 * and platform restrictions bits are set.
6006 		 */
6007 		task_set_exc_guard_default(new_task,
6008 		    proc_best_name(p),
6009 		    strlen(proc_best_name(p)),
6010 		    proc_is_simulated(p),
6011 		    proc_platform(p),
6012 		    proc_sdk(p));
6013 
6014 		/*
6015 		 * Between proc_exec_switch_task and ipc_task_enable, there is a
6016 		 * window where proc_find will return the new proc, but task_for_pid
6017 		 * and similar functions will return an error as the task ipc is not
6018 		 * enabled yet. Configure the task control port during this window
6019 		 * before other process have access to this task port.
6020 		 *
6021 		 * Must enable after resettextvp so that task port policies are not evaluated
6022 		 * until the csblob in the textvp is accurately reflected.
6023 		 */
6024 		task_set_ctrl_port_default(new_task, imgp->ip_new_thread);
6025 
6026 		/*
6027 		 * Enable new task IPC access if exec_activate_image() returned an
6028 		 * active task. (Checks active bit in ipc_task_enable() under lock).
6029 		 * Similarly, this must happen after resettextvp.
6030 		 */
6031 		ipc_task_enable(new_task);
6032 		error = process_signature(p, imgp);
6033 	}
6034 
6035 
6036 #if defined(HAS_APPLE_PAC)
6037 	if (imgp->ip_new_thread && !error) {
6038 		ml_task_set_jop_pid_from_shared_region(new_task, imgp->ip_flags & IMGPF_NOJOP);
6039 		ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
6040 	}
6041 #endif /* defined(HAS_APPLE_PAC) */
6042 
6043 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
6044 	if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
6045 		proc_knote(p, NOTE_EXEC);
6046 	}
6047 
6048 	if (imgp->ip_vp != NULLVP) {
6049 		vnode_put(imgp->ip_vp);
6050 	}
6051 	if (imgp->ip_scriptvp != NULLVP) {
6052 		vnode_put(imgp->ip_scriptvp);
6053 	}
6054 	if (imgp->ip_free_map) {
6055 		/* Free the map after dropping iocount on vnode to avoid deadlock */
6056 		vm_map_deallocate(imgp->ip_free_map);
6057 	}
6058 	if (imgp->ip_strings) {
6059 		execargs_free(imgp);
6060 	}
6061 #if CONFIG_MACF
6062 	if (imgp->ip_execlabelp) {
6063 		mac_cred_label_free(imgp->ip_execlabelp);
6064 		imgp->ip_execlabelp = NULL;
6065 	}
6066 	if (imgp->ip_scriptlabelp) {
6067 		mac_vnode_label_free(imgp->ip_scriptlabelp);
6068 		imgp->ip_scriptlabelp = NULL;
6069 	}
6070 #endif
6071 	if (imgp->ip_cs_error != OS_REASON_NULL) {
6072 		os_reason_free(imgp->ip_cs_error);
6073 		imgp->ip_cs_error = OS_REASON_NULL;
6074 	}
6075 
6076 	if (!error) {
6077 		/*
6078 		 * We need to initialize the bank context behind the protection of
6079 		 * the proc_trans lock to prevent a race with exit. We can't do this during
6080 		 * exec_activate_image because task_bank_init checks entitlements that
6081 		 * aren't loaded until subsequent calls (including exec_resettextvp).
6082 		 */
6083 		error = proc_transstart(p, 0, 0);
6084 	}
6085 
6086 	if (!error) {
6087 		task_bank_init(new_task);
6088 		proc_transend(p, 0);
6089 
6090 		// Don't inherit crash behavior across exec, but preserve crash behavior from bootargs
6091 		p->p_crash_behavior = 0;
6092 		p->p_crash_behavior_deadline = 0;
6093 #if (DEVELOPMENT || DEBUG)
6094 		set_crash_behavior_from_bootarg(p);
6095 #endif
6096 
6097 #if __arm64__
6098 		proc_footprint_entitlement_hacks(p, new_task);
6099 #endif /* __arm64__ */
6100 
6101 #if XNU_TARGET_OS_OSX
6102 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
6103 			vm_map_single_jit(get_task_map(new_task));
6104 		}
6105 #endif /* XNU_TARGET_OS_OSX */
6106 
6107 		/* Sever any extant thread affinity */
6108 		thread_affinity_exec(current_thread());
6109 
6110 		/* Inherit task role from old task to new task for exec */
6111 		proc_inherit_task_role(new_task, old_task);
6112 
6113 		thread_t main_thread = imgp->ip_new_thread;
6114 
6115 		task_set_main_thread_qos(new_task, main_thread);
6116 
6117 #if __has_feature(ptrauth_calls)
6118 		task_set_pac_exception_fatal_flag(new_task);
6119 #endif /* __has_feature(ptrauth_calls) */
6120 		task_set_jit_flags(new_task);
6121 
6122 #if CONFIG_ARCADE
6123 		/*
6124 		 * Check to see if we need to trigger an arcade upcall AST now
6125 		 * that the vnode has been reset on the task.
6126 		 */
6127 		arcade_prepare(new_task, imgp->ip_new_thread);
6128 #endif /* CONFIG_ARCADE */
6129 
6130 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
6131 
6132 		if (vm_darkwake_mode == TRUE) {
6133 			/*
6134 			 * This process is being launched when the system
6135 			 * is in darkwake. So mark it specially. This will
6136 			 * cause all its pages to be entered in the background Q.
6137 			 */
6138 			task_set_darkwake_mode(new_task, vm_darkwake_mode);
6139 		}
6140 
6141 #if CONFIG_DTRACE
6142 		dtrace_thread_didexec(imgp->ip_new_thread);
6143 
6144 		if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
6145 			(*dtrace_proc_waitfor_hook)(p);
6146 		}
6147 #endif
6148 
6149 #if CONFIG_AUDIT
6150 		if (!error && AUDIT_ENABLED() && p) {
6151 			/* Add the CDHash of the new process to the audit record */
6152 			uint8_t *cdhash = cs_get_cdhash(p);
6153 			if (cdhash) {
6154 				AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
6155 			}
6156 		}
6157 #endif
6158 	} else {
6159 		DTRACE_PROC1(exec__failure, int, error);
6160 	}
6161 
6162 exit_with_error:
6163 
6164 	/* terminate the new task it if exec failed  */
6165 	if (new_task != NULL && task_is_exec_copy(new_task)) {
6166 		task_terminate_internal(new_task);
6167 	}
6168 
6169 	if (imgp != NULL) {
6170 		/* Clear the initial wait on the thread transferring watchports */
6171 		if (imgp->ip_new_thread) {
6172 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
6173 		}
6174 
6175 		/* Transfer the watchport boost to new task */
6176 		if (!error) {
6177 			task_transfer_turnstile_watchports(old_task,
6178 			    new_task, imgp->ip_new_thread);
6179 		}
6180 		/*
6181 		 * Do not terminate the current task, if proc_exec_switch_task did not
6182 		 * switch the tasks, terminating the current task without the switch would
6183 		 * result in loosing the SIGKILL status.
6184 		 */
6185 		if (task_did_exec(old_task)) {
6186 			/* Terminate the current task, since exec will start in new task */
6187 			task_terminate_internal(old_task);
6188 		}
6189 
6190 		/* Release the thread ref returned by cloneproc */
6191 		if (imgp->ip_new_thread) {
6192 			/* clear the exec complete flag if there is an error before point of no-return */
6193 			uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
6194 			if (!exec_done && error != 0) {
6195 				clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
6196 			}
6197 			/* wake up the new exec thread */
6198 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
6199 			thread_deallocate(imgp->ip_new_thread);
6200 			imgp->ip_new_thread = NULL;
6201 		}
6202 	}
6203 
6204 	/* Release the ref returned by fork_create_child */
6205 	if (new_task) {
6206 		task_deallocate(new_task);
6207 		new_task = NULL;
6208 	}
6209 
6210 	if (should_release_proc_ref) {
6211 		proc_rele(p);
6212 	}
6213 
6214 	uthread_set_exec_data(current_uthread(), NULL);
6215 	kfree_type(typeof(*__execve_data), __execve_data);
6216 
6217 	if (inherit != NULL) {
6218 		ipc_importance_release(inherit);
6219 	}
6220 
6221 	return error;
6222 }
6223 
6224 
6225 /*
6226  * copyinptr
6227  *
6228  * Description:	Copy a pointer in from user space to a user_addr_t in kernel
6229  *		space, based on 32/64 bitness of the user space
6230  *
6231  * Parameters:	froma			User space address
6232  *		toptr			Address of kernel space user_addr_t
6233  *		ptr_size		4/8, based on 'froma' address space
6234  *
6235  * Returns:	0			Success
6236  *		EFAULT			Bad 'froma'
6237  *
6238  * Implicit returns:
6239  *		*ptr_size		Modified
6240  */
6241 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)6242 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
6243 {
6244 	int error;
6245 
6246 	if (ptr_size == 4) {
6247 		/* 64 bit value containing 32 bit address */
6248 		unsigned int i = 0;
6249 
6250 		error = copyin(froma, &i, 4);
6251 		*toptr = CAST_USER_ADDR_T(i);   /* SAFE */
6252 	} else {
6253 		error = copyin(froma, toptr, 8);
6254 	}
6255 	return error;
6256 }
6257 
6258 
6259 /*
6260  * copyoutptr
6261  *
6262  * Description:	Copy a pointer out from a user_addr_t in kernel space to
6263  *		user space, based on 32/64 bitness of the user space
6264  *
6265  * Parameters:	ua			User space address to copy to
6266  *		ptr			Address of kernel space user_addr_t
6267  *		ptr_size		4/8, based on 'ua' address space
6268  *
6269  * Returns:	0			Success
6270  *		EFAULT			Bad 'ua'
6271  *
6272  */
6273 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)6274 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
6275 {
6276 	int error;
6277 
6278 	if (ptr_size == 4) {
6279 		/* 64 bit value containing 32 bit address */
6280 		unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua);   /* SAFE */
6281 
6282 		error = copyout(&i, ptr, 4);
6283 	} else {
6284 		error = copyout(&ua, ptr, 8);
6285 	}
6286 	return error;
6287 }
6288 
6289 
6290 /*
6291  * exec_copyout_strings
6292  *
6293  * Copy out the strings segment to user space.  The strings segment is put
6294  * on a preinitialized stack frame.
6295  *
6296  * Parameters:	struct image_params *	the image parameter block
6297  *		int *			a pointer to the stack offset variable
6298  *
6299  * Returns:	0			Success
6300  *		!0			Faiure: errno
6301  *
6302  * Implicit returns:
6303  *		(*stackp)		The stack offset, modified
6304  *
6305  * Note:	The strings segment layout is backward, from the beginning
6306  *		of the top of the stack to consume the minimal amount of
6307  *		space possible; the returned stack pointer points to the
6308  *		end of the area consumed (stacks grow downward).
6309  *
6310  *		argc is an int; arg[i] are pointers; env[i] are pointers;
6311  *		the 0's are (void *)NULL's
6312  *
6313  * The stack frame layout is:
6314  *
6315  *      +-------------+ <- p->user_stack
6316  *      |     16b     |
6317  *      +-------------+
6318  *      | STRING AREA |
6319  *      |      :      |
6320  *      |      :      |
6321  *      |      :      |
6322  *      +- -- -- -- --+
6323  *      |  PATH AREA  |
6324  *      +-------------+
6325  *      |      0      |
6326  *      +-------------+
6327  *      |  applev[n]  |
6328  *      +-------------+
6329  *             :
6330  *             :
6331  *      +-------------+
6332  *      |  applev[1]  |
6333  *      +-------------+
6334  *      | exec_path / |
6335  *      |  applev[0]  |
6336  *      +-------------+
6337  *      |      0      |
6338  *      +-------------+
6339  *      |    env[n]   |
6340  *      +-------------+
6341  *             :
6342  *             :
6343  *      +-------------+
6344  *      |    env[0]   |
6345  *      +-------------+
6346  *      |      0      |
6347  *      +-------------+
6348  *      | arg[argc-1] |
6349  *      +-------------+
6350  *             :
6351  *             :
6352  *      +-------------+
6353  *      |    arg[0]   |
6354  *      +-------------+
6355  *      |     argc    |
6356  * sp-> +-------------+
6357  *
6358  * Although technically a part of the STRING AREA, we treat the PATH AREA as
6359  * a separate entity.  This allows us to align the beginning of the PATH AREA
6360  * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
6361  * which preceed it on the stack are properly aligned.
6362  */
6363 __attribute__((noinline))
6364 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)6365 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
6366 {
6367 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6368 	int     ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6369 	int     ptr_area_size;
6370 	void *ptr_buffer_start, *ptr_buffer;
6371 	size_t string_size;
6372 
6373 	user_addr_t     string_area;    /* *argv[], *env[] */
6374 	user_addr_t     ptr_area;       /* argv[], env[], applev[] */
6375 	user_addr_t argc_area;  /* argc */
6376 	user_addr_t     stack;
6377 	int error;
6378 
6379 	unsigned i;
6380 	struct copyout_desc {
6381 		char    *start_string;
6382 		int             count;
6383 #if CONFIG_DTRACE
6384 		user_addr_t     *dtrace_cookie;
6385 #endif
6386 		boolean_t       null_term;
6387 	} descriptors[] = {
6388 		{
6389 			.start_string = imgp->ip_startargv,
6390 			.count = imgp->ip_argc,
6391 #if CONFIG_DTRACE
6392 			.dtrace_cookie = &p->p_dtrace_argv,
6393 #endif
6394 			.null_term = TRUE
6395 		},
6396 		{
6397 			.start_string = imgp->ip_endargv,
6398 			.count = imgp->ip_envc,
6399 #if CONFIG_DTRACE
6400 			.dtrace_cookie = &p->p_dtrace_envp,
6401 #endif
6402 			.null_term = TRUE
6403 		},
6404 		{
6405 			.start_string = imgp->ip_strings,
6406 			.count = 1,
6407 #if CONFIG_DTRACE
6408 			.dtrace_cookie = NULL,
6409 #endif
6410 			.null_term = FALSE
6411 		},
6412 		{
6413 			.start_string = imgp->ip_endenvv,
6414 			.count = imgp->ip_applec - 1, /* exec_path handled above */
6415 #if CONFIG_DTRACE
6416 			.dtrace_cookie = NULL,
6417 #endif
6418 			.null_term = TRUE
6419 		}
6420 	};
6421 
6422 	stack = *stackp;
6423 
6424 	/*
6425 	 * All previous contributors to the string area
6426 	 * should have aligned their sub-area
6427 	 */
6428 	if (imgp->ip_strspace % ptr_size != 0) {
6429 		error = EINVAL;
6430 		goto bad;
6431 	}
6432 
6433 	/* Grow the stack down for the strings we've been building up */
6434 	string_size = imgp->ip_strendp - imgp->ip_strings;
6435 	stack -= string_size;
6436 	string_area = stack;
6437 
6438 	/*
6439 	 * Need room for one pointer for each string, plus
6440 	 * one for the NULLs terminating the argv, envv, and apple areas.
6441 	 */
6442 	ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
6443 	stack -= ptr_area_size;
6444 	ptr_area = stack;
6445 
6446 	/* We'll construct all the pointer arrays in our string buffer,
6447 	 * which we already know is aligned properly, and ip_argspace
6448 	 * was used to verify we have enough space.
6449 	 */
6450 	ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
6451 
6452 	/*
6453 	 * Need room for pointer-aligned argc slot.
6454 	 */
6455 	stack -= ptr_size;
6456 	argc_area = stack;
6457 
6458 	/*
6459 	 * Record the size of the arguments area so that sysctl_procargs()
6460 	 * can return the argument area without having to parse the arguments.
6461 	 */
6462 	proc_lock(p);
6463 	p->p_argc = imgp->ip_argc;
6464 	p->p_argslen = (int)(*stackp - string_area);
6465 	proc_unlock(p);
6466 
6467 	/* Return the initial stack address: the location of argc */
6468 	*stackp = stack;
6469 
6470 	/*
6471 	 * Copy out the entire strings area.
6472 	 */
6473 	error = copyout(imgp->ip_strings, string_area,
6474 	    string_size);
6475 	if (error) {
6476 		goto bad;
6477 	}
6478 
6479 	for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
6480 		char *cur_string = descriptors[i].start_string;
6481 		int j;
6482 
6483 #if CONFIG_DTRACE
6484 		if (descriptors[i].dtrace_cookie) {
6485 			proc_lock(p);
6486 			*descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
6487 			proc_unlock(p);
6488 		}
6489 #endif /* CONFIG_DTRACE */
6490 
6491 		/*
6492 		 * For each segment (argv, envv, applev), copy as many pointers as requested
6493 		 * to our pointer buffer.
6494 		 */
6495 		for (j = 0; j < descriptors[i].count; j++) {
6496 			user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
6497 
6498 			/* Copy out the pointer to the current string. Alignment has been verified  */
6499 			if (ptr_size == 8) {
6500 				*(uint64_t *)ptr_buffer = (uint64_t)cur_address;
6501 			} else {
6502 				*(uint32_t *)ptr_buffer = (uint32_t)cur_address;
6503 			}
6504 
6505 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
6506 			cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
6507 		}
6508 
6509 		if (descriptors[i].null_term) {
6510 			if (ptr_size == 8) {
6511 				*(uint64_t *)ptr_buffer = 0ULL;
6512 			} else {
6513 				*(uint32_t *)ptr_buffer = 0;
6514 			}
6515 
6516 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
6517 		}
6518 	}
6519 
6520 	/*
6521 	 * Copy out all our pointer arrays in bulk.
6522 	 */
6523 	error = copyout(ptr_buffer_start, ptr_area,
6524 	    ptr_area_size);
6525 	if (error) {
6526 		goto bad;
6527 	}
6528 
6529 	/* argc (int32, stored in a ptr_size area) */
6530 	error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
6531 	if (error) {
6532 		goto bad;
6533 	}
6534 
6535 bad:
6536 	return error;
6537 }
6538 
6539 
6540 /*
6541  * exec_extract_strings
6542  *
6543  * Copy arguments and environment from user space into work area; we may
6544  * have already copied some early arguments into the work area, and if
6545  * so, any arguments opied in are appended to those already there.
6546  * This function is the primary manipulator of ip_argspace, since
6547  * these are the arguments the client of execve(2) knows about. After
6548  * each argv[]/envv[] string is copied, we charge the string length
6549  * and argv[]/envv[] pointer slot to ip_argspace, so that we can
6550  * full preflight the arg list size.
6551  *
6552  * Parameters:	struct image_params *	the image parameter block
6553  *
6554  * Returns:	0			Success
6555  *		!0			Failure: errno
6556  *
6557  * Implicit returns;
6558  *		(imgp->ip_argc)		Count of arguments, updated
6559  *		(imgp->ip_envc)		Count of environment strings, updated
6560  *		(imgp->ip_argspace)	Count of remaining of NCARGS
6561  *		(imgp->ip_interp_buffer)	Interpreter and args (mutated in place)
6562  *
6563  *
6564  * Note:	The argument and environment vectors are user space pointers
6565  *		to arrays of user space pointers.
6566  */
6567 __attribute__((noinline))
6568 static int
exec_extract_strings(struct image_params * imgp)6569 exec_extract_strings(struct image_params *imgp)
6570 {
6571 	int error = 0;
6572 	int     ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
6573 	int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6574 	user_addr_t     argv = imgp->ip_user_argv;
6575 	user_addr_t     envv = imgp->ip_user_envv;
6576 
6577 	/*
6578 	 * Adjust space reserved for the path name by however much padding it
6579 	 * needs. Doing this here since we didn't know if this would be a 32-
6580 	 * or 64-bit process back in exec_save_path.
6581 	 */
6582 	while (imgp->ip_strspace % new_ptr_size != 0) {
6583 		*imgp->ip_strendp++ = '\0';
6584 		imgp->ip_strspace--;
6585 		/* imgp->ip_argspace--; not counted towards exec args total */
6586 	}
6587 
6588 	/*
6589 	 * From now on, we start attributing string space to ip_argspace
6590 	 */
6591 	imgp->ip_startargv = imgp->ip_strendp;
6592 	imgp->ip_argc = 0;
6593 
6594 	if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
6595 		user_addr_t     arg;
6596 		char *argstart, *ch;
6597 
6598 		/* First, the arguments in the "#!" string are tokenized and extracted. */
6599 		argstart = imgp->ip_interp_buffer;
6600 		while (argstart) {
6601 			ch = argstart;
6602 			while (*ch && !IS_WHITESPACE(*ch)) {
6603 				ch++;
6604 			}
6605 
6606 			if (*ch == '\0') {
6607 				/* last argument, no need to NUL-terminate */
6608 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
6609 				argstart = NULL;
6610 			} else {
6611 				/* NUL-terminate */
6612 				*ch = '\0';
6613 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
6614 
6615 				/*
6616 				 * Find the next string. We know spaces at the end of the string have already
6617 				 * been stripped.
6618 				 */
6619 				argstart = ch + 1;
6620 				while (IS_WHITESPACE(*argstart)) {
6621 					argstart++;
6622 				}
6623 			}
6624 
6625 			/* Error-check, regardless of whether this is the last interpreter arg or not */
6626 			if (error) {
6627 				goto bad;
6628 			}
6629 			if (imgp->ip_argspace < new_ptr_size) {
6630 				error = E2BIG;
6631 				goto bad;
6632 			}
6633 			imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6634 			imgp->ip_argc++;
6635 		}
6636 
6637 		if (argv != 0LL) {
6638 			/*
6639 			 * If we are running an interpreter, replace the av[0] that was
6640 			 * passed to execve() with the path name that was
6641 			 * passed to execve() for interpreters which do not use the PATH
6642 			 * to locate their script arguments.
6643 			 */
6644 			error = copyinptr(argv, &arg, ptr_size);
6645 			if (error) {
6646 				goto bad;
6647 			}
6648 			if (arg != 0LL) {
6649 				argv += ptr_size; /* consume without using */
6650 			}
6651 		}
6652 
6653 		if (imgp->ip_interp_sugid_fd != -1) {
6654 			char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
6655 			snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
6656 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
6657 		} else {
6658 			error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
6659 		}
6660 
6661 		if (error) {
6662 			goto bad;
6663 		}
6664 		if (imgp->ip_argspace < new_ptr_size) {
6665 			error = E2BIG;
6666 			goto bad;
6667 		}
6668 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6669 		imgp->ip_argc++;
6670 	}
6671 
6672 	while (argv != 0LL) {
6673 		user_addr_t     arg;
6674 
6675 		error = copyinptr(argv, &arg, ptr_size);
6676 		if (error) {
6677 			goto bad;
6678 		}
6679 
6680 		if (arg == 0LL) {
6681 			break;
6682 		}
6683 
6684 		argv += ptr_size;
6685 
6686 		/*
6687 		 * av[n...] = arg[n]
6688 		 */
6689 		error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
6690 		if (error) {
6691 			goto bad;
6692 		}
6693 		if (imgp->ip_argspace < new_ptr_size) {
6694 			error = E2BIG;
6695 			goto bad;
6696 		}
6697 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6698 		imgp->ip_argc++;
6699 	}
6700 
6701 	/* Save space for argv[] NULL terminator */
6702 	if (imgp->ip_argspace < new_ptr_size) {
6703 		error = E2BIG;
6704 		goto bad;
6705 	}
6706 	imgp->ip_argspace -= new_ptr_size;
6707 
6708 	/* Note where the args ends and env begins. */
6709 	imgp->ip_endargv = imgp->ip_strendp;
6710 	imgp->ip_envc = 0;
6711 
6712 	/* Now, get the environment */
6713 	while (envv != 0LL) {
6714 		user_addr_t     env;
6715 
6716 		error = copyinptr(envv, &env, ptr_size);
6717 		if (error) {
6718 			goto bad;
6719 		}
6720 
6721 		envv += ptr_size;
6722 		if (env == 0LL) {
6723 			break;
6724 		}
6725 		/*
6726 		 * av[n...] = env[n]
6727 		 */
6728 		error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
6729 		if (error) {
6730 			goto bad;
6731 		}
6732 		if (imgp->ip_argspace < new_ptr_size) {
6733 			error = E2BIG;
6734 			goto bad;
6735 		}
6736 		imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
6737 		imgp->ip_envc++;
6738 	}
6739 
6740 	/* Save space for envv[] NULL terminator */
6741 	if (imgp->ip_argspace < new_ptr_size) {
6742 		error = E2BIG;
6743 		goto bad;
6744 	}
6745 	imgp->ip_argspace -= new_ptr_size;
6746 
6747 	/* Align the tail of the combined argv+envv area */
6748 	while (imgp->ip_strspace % new_ptr_size != 0) {
6749 		if (imgp->ip_argspace < 1) {
6750 			error = E2BIG;
6751 			goto bad;
6752 		}
6753 		*imgp->ip_strendp++ = '\0';
6754 		imgp->ip_strspace--;
6755 		imgp->ip_argspace--;
6756 	}
6757 
6758 	/* Note where the envv ends and applev begins. */
6759 	imgp->ip_endenvv = imgp->ip_strendp;
6760 
6761 	/*
6762 	 * From now on, we are no longer charging argument
6763 	 * space to ip_argspace.
6764 	 */
6765 
6766 bad:
6767 	return error;
6768 }
6769 
6770 /*
6771  * Libc has an 8-element array set up for stack guard values.  It only fills
6772  * in one of those entries, and both gcc and llvm seem to use only a single
6773  * 8-byte guard.  Until somebody needs more than an 8-byte guard value, don't
6774  * do the work to construct them.
6775  */
6776 #define GUARD_VALUES 1
6777 #define GUARD_KEY "stack_guard="
6778 
6779 /*
6780  * System malloc needs some entropy when it is initialized.
6781  */
6782 #define ENTROPY_VALUES 2
6783 #define ENTROPY_KEY "malloc_entropy="
6784 
6785 /*
6786  * libplatform needs a random pointer-obfuscation value when it is initialized.
6787  */
6788 #define PTR_MUNGE_VALUES 1
6789 #define PTR_MUNGE_KEY "ptr_munge="
6790 
6791 /*
6792  * System malloc engages nanozone for UIAPP.
6793  */
6794 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
6795 
6796 /*
6797  * Used to pass experiment flags up to libmalloc.
6798  */
6799 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
6800 
6801 /*
6802  * Passes information about hardened heap/"hardened runtime" entitlements to libsystem/libmalloc
6803  */
6804 #define HARDENED_RUNTIME_KEY "HardenedRuntime="
6805 
6806 #define PFZ_KEY "pfz="
6807 extern user32_addr_t commpage_text32_location;
6808 extern user64_addr_t commpage_text64_location;
6809 
6810 extern uuid_string_t bootsessionuuid_string;
6811 static TUNABLE(uint32_t, exe_boothash_salt, "exe_boothash_salt", 0);
6812 
6813 __startup_func
6814 static void
exe_boothash_salt_generate(void)6815 exe_boothash_salt_generate(void)
6816 {
6817 	if (!PE_parse_boot_argn("exe_boothash_salt", NULL, 0)) {
6818 		read_random(&exe_boothash_salt, sizeof(exe_boothash_salt));
6819 	}
6820 }
6821 STARTUP(EARLY_BOOT, STARTUP_RANK_MIDDLE, exe_boothash_salt_generate);
6822 
6823 
6824 #define MAIN_STACK_VALUES 4
6825 #define MAIN_STACK_KEY "main_stack="
6826 
6827 #define FSID_KEY "executable_file="
6828 #define DYLD_FSID_KEY "dyld_file="
6829 #define CDHASH_KEY "executable_cdhash="
6830 #define DYLD_FLAGS_KEY "dyld_flags="
6831 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
6832 #define APP_BOOT_SESSION_KEY "executable_boothash="
6833 #if __has_feature(ptrauth_calls)
6834 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
6835 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
6836 #endif /* __has_feature(ptrauth_calls) */
6837 #define MAIN_TH_PORT_KEY "th_port="
6838 
6839 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
6840 
6841 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
6842 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
6843 
6844 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6845 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
6846 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6847 
6848 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)6849 exec_add_entropy_key(struct image_params *imgp,
6850     const char *key,
6851     int values,
6852     boolean_t embedNUL)
6853 {
6854 	const int limit = 8;
6855 	uint64_t entropy[limit];
6856 	char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
6857 	if (values > limit) {
6858 		values = limit;
6859 	}
6860 
6861 	read_random(entropy, sizeof(entropy[0]) * values);
6862 
6863 	if (embedNUL) {
6864 		entropy[0] &= ~(0xffull << 8);
6865 	}
6866 
6867 	int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
6868 	size_t remaining = sizeof(str) - len;
6869 	for (int i = 1; i < values && remaining > 0; ++i) {
6870 		size_t start = sizeof(str) - remaining;
6871 		len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
6872 		remaining -= len;
6873 	}
6874 
6875 	return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
6876 }
6877 
6878 /*
6879  * Build up the contents of the apple[] string vector
6880  */
6881 #if (DEVELOPMENT || DEBUG)
6882 extern uint64_t dyld_flags;
6883 #endif
6884 
6885 #if __has_feature(ptrauth_calls)
6886 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)6887 is_arm64e_running_as_arm64(const struct image_params *imgp)
6888 {
6889 	return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
6890 	       (imgp->ip_flags & IMGPF_NOJOP);
6891 }
6892 #endif /* __has_feature(ptrauth_calls) */
6893 
6894 _Atomic uint64_t libmalloc_experiment_factors = 0;
6895 
6896 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result,task_t task)6897 exec_add_apple_strings(struct image_params *imgp,
6898     const load_result_t *load_result, task_t task)
6899 {
6900 	int error;
6901 	int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6902 	thread_t new_thread;
6903 	ipc_port_t sright;
6904 	uint64_t local_experiment_factors = 0;
6905 
6906 	/* exec_save_path stored the first string */
6907 	imgp->ip_applec = 1;
6908 
6909 	/* adding the pfz string */
6910 	{
6911 		char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
6912 
6913 		if (img_ptr_size == 8) {
6914 			__assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
6915 			assert(ret < sizeof(pfz_string));
6916 		} else {
6917 			snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
6918 		}
6919 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
6920 		if (error) {
6921 			printf("Failed to add the pfz string with error %d\n", error);
6922 			goto bad;
6923 		}
6924 		imgp->ip_applec++;
6925 	}
6926 
6927 	/* adding the NANO_ENGAGE_KEY key */
6928 	if (imgp->ip_px_sa) {
6929 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6930 		int proc_flags = psa->psa_flags;
6931 
6932 		if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
6933 			const char *nano_string = NANO_ENGAGE_KEY;
6934 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
6935 			if (error) {
6936 				goto bad;
6937 			}
6938 			imgp->ip_applec++;
6939 		}
6940 	}
6941 
6942 	/*
6943 	 * Supply libc with a collection of random values to use when
6944 	 * implementing -fstack-protector.
6945 	 *
6946 	 * (The first random string always contains an embedded NUL so that
6947 	 * __stack_chk_guard also protects against C string vulnerabilities)
6948 	 */
6949 	error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
6950 	if (error) {
6951 		goto bad;
6952 	}
6953 	imgp->ip_applec++;
6954 
6955 	/*
6956 	 * Supply libc with entropy for system malloc.
6957 	 */
6958 	error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
6959 	if (error) {
6960 		goto bad;
6961 	}
6962 	imgp->ip_applec++;
6963 
6964 	/*
6965 	 * Supply libpthread & libplatform with a random value to use for pointer
6966 	 * obfuscation.
6967 	 */
6968 	error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
6969 	if (error) {
6970 		goto bad;
6971 	}
6972 	imgp->ip_applec++;
6973 
6974 	/*
6975 	 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
6976 	 * stack if it was allocated by the kernel.
6977 	 *
6978 	 * The guard page is not included in this stack size as libpthread
6979 	 * expects to add it back in after receiving this value.
6980 	 */
6981 	if (load_result->unixproc) {
6982 		char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
6983 		snprintf(stack_string, sizeof(stack_string),
6984 		    MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
6985 		    (uint64_t)load_result->user_stack,
6986 		    (uint64_t)load_result->user_stack_size,
6987 		    (uint64_t)load_result->user_stack_alloc,
6988 		    (uint64_t)load_result->user_stack_alloc_size);
6989 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
6990 		if (error) {
6991 			goto bad;
6992 		}
6993 		imgp->ip_applec++;
6994 	}
6995 
6996 	if (imgp->ip_vattr) {
6997 		uint64_t fsid    = vnode_get_va_fsid(imgp->ip_vattr);
6998 		uint64_t fsobjid = imgp->ip_vattr->va_fileid;
6999 
7000 		char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
7001 		snprintf(fsid_string, sizeof(fsid_string),
7002 		    FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
7003 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
7004 		if (error) {
7005 			goto bad;
7006 		}
7007 		imgp->ip_applec++;
7008 	}
7009 
7010 	if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
7011 		char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
7012 		snprintf(fsid_string, sizeof(fsid_string),
7013 		    DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
7014 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
7015 		if (error) {
7016 			goto bad;
7017 		}
7018 		imgp->ip_applec++;
7019 	}
7020 
7021 	uint8_t cdhash[SHA1_RESULTLEN];
7022 	int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash, NULL);
7023 	if (cdhash_errror == 0) {
7024 		char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
7025 		strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
7026 		char *p = hash_string + sizeof(CDHASH_KEY) - 1;
7027 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
7028 			snprintf(p, 3, "%02x", (int) cdhash[i]);
7029 			p += 2;
7030 		}
7031 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
7032 		if (error) {
7033 			goto bad;
7034 		}
7035 		imgp->ip_applec++;
7036 
7037 		/* hash together cd-hash and boot-session-uuid */
7038 		uint8_t sha_digest[SHA256_DIGEST_LENGTH];
7039 		SHA256_CTX sha_ctx;
7040 		SHA256_Init(&sha_ctx);
7041 		SHA256_Update(&sha_ctx, &exe_boothash_salt, sizeof(exe_boothash_salt));
7042 		SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
7043 		SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
7044 		SHA256_Final(sha_digest, &sha_ctx);
7045 		char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
7046 		strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
7047 		char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
7048 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
7049 			snprintf(s, 3, "%02x", (int) sha_digest[i]);
7050 			s += 2;
7051 		}
7052 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
7053 		if (error) {
7054 			goto bad;
7055 		}
7056 		imgp->ip_applec++;
7057 	}
7058 #if (DEVELOPMENT || DEBUG)
7059 	if (dyld_flags) {
7060 		char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
7061 		snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
7062 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
7063 		if (error) {
7064 			goto bad;
7065 		}
7066 		imgp->ip_applec++;
7067 	}
7068 #endif
7069 	if (imgp->ip_subsystem_root_path) {
7070 		size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
7071 		char subsystem_root_path_string[buffer_len];
7072 		int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
7073 
7074 		if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
7075 			error = ENAMETOOLONG;
7076 			goto bad;
7077 		}
7078 
7079 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
7080 		if (error) {
7081 			goto bad;
7082 		}
7083 
7084 		imgp->ip_applec++;
7085 	}
7086 #if __has_feature(ptrauth_calls)
7087 	if (is_arm64e_running_as_arm64(imgp)) {
7088 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
7089 		if (error) {
7090 			goto bad;
7091 		}
7092 
7093 		imgp->ip_applec++;
7094 	}
7095 #endif /* __has_feature(ptrauth_calls) */
7096 
7097 
7098 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
7099 	{
7100 		char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
7101 		strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
7102 		bool allowAll = bootarg_arm64e_preview_abi;
7103 		strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
7104 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
7105 		if (error) {
7106 			goto bad;
7107 		}
7108 
7109 		imgp->ip_applec++;
7110 	}
7111 #endif
7112 	/*
7113 	 * Add main thread mach port name
7114 	 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
7115 	 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
7116 	 * against libpthread.
7117 	 */
7118 	if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
7119 		thread_reference(new_thread);
7120 		sright = convert_thread_to_port_immovable(new_thread);
7121 		task_t new_task = get_threadtask(new_thread);
7122 		mach_port_name_t name = ipc_port_copyout_send_pinned(sright, get_task_ipcspace(new_task));
7123 		char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
7124 		snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
7125 
7126 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
7127 		if (error) {
7128 			goto bad;
7129 		}
7130 		imgp->ip_applec++;
7131 	}
7132 
7133 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
7134 	if (imgp->ip_px_sa != NULL) {
7135 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
7136 		if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
7137 			const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
7138 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
7139 			if (error) {
7140 				goto bad;
7141 			}
7142 			imgp->ip_applec++;
7143 		}
7144 	}
7145 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
7146 
7147 	/* adding the libmalloc experiment string */
7148 	local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
7149 	if (__improbable(local_experiment_factors != 0)) {
7150 		char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
7151 
7152 		snprintf(
7153 			libmalloc_experiment_factors_string,
7154 			sizeof(libmalloc_experiment_factors_string),
7155 			LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
7156 			local_experiment_factors);
7157 		error = exec_add_user_string(
7158 			imgp,
7159 			CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
7160 			UIO_SYSSPACE,
7161 			FALSE);
7162 		if (error) {
7163 			printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
7164 			goto bad;
7165 		}
7166 		imgp->ip_applec++;
7167 	}
7168 
7169 	/*
7170 	 * Push down the task security configuration. To reduce confusion when userland parses the information
7171 	 * still push an empty security configuration if nothing is active.
7172 	 */
7173 	{
7174 		#define SECURITY_CONFIG_KEY "security_config="
7175 		char security_config_str[strlen(SECURITY_CONFIG_KEY) + HEX_STR_LEN + 1];
7176 
7177 		snprintf(security_config_str, sizeof(security_config_str),
7178 		    SECURITY_CONFIG_KEY "0x%x", task_get_security_config(task));
7179 
7180 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(security_config_str), UIO_SYSSPACE, FALSE);
7181 		if (error) {
7182 			printf("Failed to add the security config string with error %d\n", error);
7183 			goto bad;
7184 		}
7185 		imgp->ip_applec++;
7186 	}
7187 
7188 
7189 #if HAS_MTE || HAS_MTE_EMULATION_SHIMS
7190 	if (task_has_sec(task)) {
7191 		const char *sec_transition_shims = "has_sec_transition=1";
7192 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(sec_transition_shims), UIO_SYSSPACE, FALSE);
7193 		if (error) {
7194 			printf("Failed to add security translation shims notification\n");
7195 			goto bad;
7196 		}
7197 
7198 		imgp->ip_applec++;
7199 
7200 		/* Push down MTE-specific configuration options that allocators may be interested into. */
7201 		#define SEC_TRANSITION_POLICY_KEY "sec_transition_policy="
7202 
7203 		char sec_transition_policy[strlen(SEC_TRANSITION_POLICY_KEY) + HEX_STR_LEN + 1];
7204 
7205 		snprintf(sec_transition_policy, sizeof(sec_transition_policy),
7206 		    SEC_TRANSITION_POLICY_KEY "0x%x", task_get_sec_policy(task));
7207 
7208 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(sec_transition_policy), UIO_SYSSPACE, FALSE);
7209 		if (error) {
7210 			printf("Failed to add the security transition policy string with error %d\n", error);
7211 			goto bad;
7212 		}
7213 		imgp->ip_applec++;
7214 	}
7215 #endif /* HAS_MTE || HAS_MTE_EMULATION_SHIMS */
7216 
7217 
7218 	if (load_result->hardened_browser) {
7219 		const size_t HR_STRING_SIZE = sizeof(HARDENED_RUNTIME_KEY) + HR_FLAGS_NUM_NIBBLES + 2 + 1;
7220 		char hardened_runtime[HR_STRING_SIZE];
7221 		snprintf(hardened_runtime, HR_STRING_SIZE, HARDENED_RUNTIME_KEY"0x%x", load_result->hardened_browser);
7222 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hardened_runtime), UIO_SYSSPACE, FALSE);
7223 		if (error) {
7224 			printf("Failed to add hardened runtime flag with error %d\n", error);
7225 			goto bad;
7226 		}
7227 		imgp->ip_applec++;
7228 	}
7229 	/* Align the tail of the combined applev area */
7230 	while (imgp->ip_strspace % img_ptr_size != 0) {
7231 		*imgp->ip_strendp++ = '\0';
7232 		imgp->ip_strspace--;
7233 	}
7234 
7235 bad:
7236 	return error;
7237 }
7238 
7239 /*
7240  * exec_check_permissions
7241  *
7242  * Description:	Verify that the file that is being attempted to be executed
7243  *		is in fact allowed to be executed based on it POSIX file
7244  *		permissions and other access control criteria
7245  *
7246  * Parameters:	struct image_params *	the image parameter block
7247  *
7248  * Returns:	0			Success
7249  *		EACCES			Permission denied
7250  *		ENOEXEC			Executable file format error
7251  *		ETXTBSY			Text file busy [misuse of error code]
7252  *	vnode_getattr:???
7253  *	vnode_authorize:???
7254  */
7255 static int
exec_check_permissions(struct image_params * imgp)7256 exec_check_permissions(struct image_params *imgp)
7257 {
7258 	struct vnode *vp = imgp->ip_vp;
7259 	struct vnode_attr *vap = imgp->ip_vattr;
7260 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
7261 	int error;
7262 	kauth_action_t action;
7263 
7264 	/* Only allow execution of regular files */
7265 	if (!vnode_isreg(vp)) {
7266 		return EACCES;
7267 	}
7268 
7269 	/* Get the file attributes that we will be using here and elsewhere */
7270 	VATTR_INIT(vap);
7271 	VATTR_WANTED(vap, va_uid);
7272 	VATTR_WANTED(vap, va_gid);
7273 	VATTR_WANTED(vap, va_mode);
7274 	VATTR_WANTED(vap, va_fsid);
7275 	VATTR_WANTED(vap, va_fsid64);
7276 	VATTR_WANTED(vap, va_fileid);
7277 	VATTR_WANTED(vap, va_data_size);
7278 	if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
7279 		return error;
7280 	}
7281 
7282 	/*
7283 	 * Ensure that at least one execute bit is on - otherwise root
7284 	 * will always succeed, and we don't want to happen unless the
7285 	 * file really is executable.
7286 	 */
7287 	if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
7288 		return EACCES;
7289 	}
7290 
7291 	/* Disallow zero length files */
7292 	if (vap->va_data_size == 0) {
7293 		return ENOEXEC;
7294 	}
7295 
7296 	imgp->ip_arch_offset = (user_size_t)0;
7297 #if __LP64__
7298 	imgp->ip_arch_size = vap->va_data_size;
7299 #else
7300 	if (vap->va_data_size > UINT32_MAX) {
7301 		return ENOEXEC;
7302 	}
7303 	imgp->ip_arch_size = (user_size_t)vap->va_data_size;
7304 #endif
7305 
7306 	/* Disable setuid-ness for traced programs or if MNT_NOSUID */
7307 	if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
7308 		vap->va_mode &= ~(VSUID | VSGID);
7309 	}
7310 
7311 	/*
7312 	 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
7313 	 * flags for setuid/setgid binaries.
7314 	 */
7315 	if (vap->va_mode & (VSUID | VSGID)) {
7316 		imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
7317 	}
7318 
7319 #if CONFIG_MACF
7320 	error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
7321 	if (error) {
7322 		return error;
7323 	}
7324 #endif
7325 
7326 	/* Check for execute permission */
7327 	action = KAUTH_VNODE_EXECUTE;
7328 	/* Traced images must also be readable */
7329 	if (p->p_lflag & P_LTRACED) {
7330 		action |= KAUTH_VNODE_READ_DATA;
7331 	}
7332 	if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
7333 		return error;
7334 	}
7335 
7336 #if 0
7337 	/* Don't let it run if anyone had it open for writing */
7338 	vnode_lock(vp);
7339 	if (vp->v_writecount) {
7340 		panic("going to return ETXTBSY %x", vp);
7341 		vnode_unlock(vp);
7342 		return ETXTBSY;
7343 	}
7344 	vnode_unlock(vp);
7345 #endif
7346 
7347 	/* XXX May want to indicate to underlying FS that vnode is open */
7348 
7349 	return error;
7350 }
7351 
7352 
7353 /*
7354  * exec_handle_sugid
7355  *
7356  * Initially clear the P_SUGID in the process flags; if an SUGID process is
7357  * exec'ing a non-SUGID image, then  this is the point of no return.
7358  *
7359  * If the image being activated is SUGID, then replace the credential with a
7360  * copy, disable tracing (unless the tracing process is root), reset the
7361  * mach task port to revoke it, set the P_SUGID bit,
7362  *
7363  * If the saved user and group ID will be changing, then make sure it happens
7364  * to a new credential, rather than a shared one.
7365  *
7366  * Set the security token (this is probably obsolete, given that the token
7367  * should not technically be separate from the credential itself).
7368  *
7369  * Parameters:	struct image_params *	the image parameter block
7370  *
7371  * Returns:	void			No failure indication
7372  *
7373  * Implicit returns:
7374  *		<process credential>	Potentially modified/replaced
7375  *		<task port>		Potentially revoked
7376  *		<process flags>		P_SUGID bit potentially modified
7377  *		<security token>	Potentially modified
7378  */
7379 __attribute__((noinline))
7380 static int
exec_handle_sugid(struct image_params * imgp)7381 exec_handle_sugid(struct image_params *imgp)
7382 {
7383 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
7384 	kauth_cred_t            cred = vfs_context_ucred(imgp->ip_vfs_context);
7385 	int                     i;
7386 	int                     leave_sugid_clear = 0;
7387 	int                     mac_reset_ipc = 0;
7388 	int                     error = 0;
7389 #if CONFIG_MACF
7390 	int                     mac_transition, disjoint_cred = 0;
7391 	int             label_update_return = 0;
7392 
7393 	/*
7394 	 * Determine whether a call to update the MAC label will result in the
7395 	 * credential changing.
7396 	 *
7397 	 * Note:	MAC policies which do not actually end up modifying
7398 	 *		the label subsequently are strongly encouraged to
7399 	 *		return 0 for this check, since a non-zero answer will
7400 	 *		slow down the exec fast path for normal binaries.
7401 	 */
7402 	mac_transition = mac_cred_check_label_update_execve(
7403 		imgp->ip_vfs_context,
7404 		imgp->ip_vp,
7405 		imgp->ip_arch_offset,
7406 		imgp->ip_scriptvp,
7407 		imgp->ip_scriptlabelp,
7408 		imgp->ip_execlabelp,
7409 		p,
7410 		&imgp->ip_px_smpx);
7411 #endif
7412 
7413 	OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
7414 
7415 	/*
7416 	 * Order of the following is important; group checks must go last,
7417 	 * as we use the success of the 'ismember' check combined with the
7418 	 * failure of the explicit match to indicate that we will be setting
7419 	 * the egid of the process even though the new process did not
7420 	 * require VSUID/VSGID bits in order for it to set the new group as
7421 	 * its egid.
7422 	 *
7423 	 * Note:	Technically, by this we are implying a call to
7424 	 *		setegid() in the new process, rather than implying
7425 	 *		it used its VSGID bit to set the effective group,
7426 	 *		even though there is no code in that process to make
7427 	 *		such a call.
7428 	 */
7429 	if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
7430 	    kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
7431 	    ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
7432 	    ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
7433 	    (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
7434 #if CONFIG_MACF
7435 /* label for MAC transition and neither VSUID nor VSGID */
7436 handle_mac_transition:
7437 #endif
7438 
7439 #if CONFIG_SETUID
7440 		/*
7441 		 * Replace the credential with a copy of itself if euid or
7442 		 * egid change.
7443 		 *
7444 		 * Note:	setuid binaries will automatically opt out of
7445 		 *		group resolver participation as a side effect
7446 		 *		of this operation.  This is an intentional
7447 		 *		part of the security model, which requires a
7448 		 *		participating credential be established by
7449 		 *		escalating privilege, setting up all other
7450 		 *		aspects of the credential including whether
7451 		 *		or not to participate in external group
7452 		 *		membership resolution, then dropping their
7453 		 *		effective privilege to that of the desired
7454 		 *		final credential state.
7455 		 *
7456 		 * Modifications to p_ucred must be guarded using the
7457 		 * proc's ucred lock. This prevents others from accessing
7458 		 * a garbage credential.
7459 		 */
7460 
7461 		if (imgp->ip_origvattr->va_mode & VSUID) {
7462 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
7463 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
7464 				return kauth_cred_model_setresuid(model,
7465 				KAUTH_UID_NONE,
7466 				imgp->ip_origvattr->va_uid,
7467 				imgp->ip_origvattr->va_uid,
7468 				KAUTH_UID_NONE);
7469 			});
7470 		}
7471 
7472 		if (imgp->ip_origvattr->va_mode & VSGID) {
7473 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
7474 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
7475 				return kauth_cred_model_setresgid(model,
7476 				KAUTH_GID_NONE,
7477 				imgp->ip_origvattr->va_gid,
7478 				imgp->ip_origvattr->va_gid);
7479 			});
7480 		}
7481 #endif /* CONFIG_SETUID */
7482 
7483 #if CONFIG_MACF
7484 		/*
7485 		 * If a policy has indicated that it will transition the label,
7486 		 * before making the call into the MAC policies, get a new
7487 		 * duplicate credential, so they can modify it without
7488 		 * modifying any others sharing it.
7489 		 */
7490 		if (mac_transition) {
7491 			/*
7492 			 * This hook may generate upcalls that require
7493 			 * importance donation from the kernel.
7494 			 * (23925818)
7495 			 */
7496 			thread_t thread = current_thread();
7497 			thread_enable_send_importance(thread, TRUE);
7498 			kauth_proc_label_update_execve(p,
7499 			    imgp->ip_vfs_context,
7500 			    imgp->ip_vp,
7501 			    imgp->ip_arch_offset,
7502 			    imgp->ip_scriptvp,
7503 			    imgp->ip_scriptlabelp,
7504 			    imgp->ip_execlabelp,
7505 			    &imgp->ip_csflags,
7506 			    &imgp->ip_px_smpx,
7507 			    &disjoint_cred,                     /* will be non zero if disjoint */
7508 			    &label_update_return);
7509 			thread_enable_send_importance(thread, FALSE);
7510 
7511 			if (disjoint_cred) {
7512 				/*
7513 				 * If updating the MAC label resulted in a
7514 				 * disjoint credential, flag that we need to
7515 				 * set the P_SUGID bit.  This protects
7516 				 * against debuggers being attached by an
7517 				 * insufficiently privileged process onto the
7518 				 * result of a transition to a more privileged
7519 				 * credential.
7520 				 */
7521 				leave_sugid_clear = 0;
7522 			}
7523 
7524 			imgp->ip_mac_return = label_update_return;
7525 		}
7526 
7527 		mac_reset_ipc = mac_proc_check_inherit_ipc_ports(p, p->p_textvp, p->p_textoff, imgp->ip_vp, imgp->ip_arch_offset, imgp->ip_scriptvp);
7528 
7529 #endif  /* CONFIG_MACF */
7530 
7531 		/*
7532 		 * If 'leave_sugid_clear' is non-zero, then we passed the
7533 		 * VSUID and MACF checks, and successfully determined that
7534 		 * the previous cred was a member of the VSGID group, but
7535 		 * that it was not the default at the time of the execve,
7536 		 * and that the post-labelling credential was not disjoint.
7537 		 * So we don't set the P_SUGID or reset mach ports and fds
7538 		 * on the basis of simply running this code.
7539 		 */
7540 		if (mac_reset_ipc || !leave_sugid_clear) {
7541 			/*
7542 			 * Have mach reset the task and thread ports.
7543 			 * We don't want anyone who had the ports before
7544 			 * a setuid exec to be able to access/control the
7545 			 * task/thread after.
7546 			 */
7547 			ipc_task_reset((imgp->ip_new_thread != NULL) ?
7548 			    get_threadtask(imgp->ip_new_thread) : proc_task(p));
7549 			ipc_thread_reset((imgp->ip_new_thread != NULL) ?
7550 			    imgp->ip_new_thread : current_thread());
7551 		}
7552 
7553 		if (!leave_sugid_clear) {
7554 			/*
7555 			 * Flag the process as setuid.
7556 			 */
7557 			OSBitOrAtomic(P_SUGID, &p->p_flag);
7558 
7559 			/*
7560 			 * Radar 2261856; setuid security hole fix
7561 			 * XXX For setuid processes, attempt to ensure that
7562 			 * stdin, stdout, and stderr are already allocated.
7563 			 * We do not want userland to accidentally allocate
7564 			 * descriptors in this range which has implied meaning
7565 			 * to libc.
7566 			 */
7567 			for (i = 0; i < 3; i++) {
7568 				if (fp_get_noref_locked(p, i) != NULL) {
7569 					continue;
7570 				}
7571 
7572 				/*
7573 				 * Do the kernel equivalent of
7574 				 *
7575 				 *      if i == 0
7576 				 *              (void) open("/dev/null", O_RDONLY);
7577 				 *      else
7578 				 *              (void) open("/dev/null", O_WRONLY);
7579 				 */
7580 
7581 				struct fileproc *fp;
7582 				int indx;
7583 				int flag;
7584 				struct nameidata *ndp = NULL;
7585 
7586 				if (i == 0) {
7587 					flag = FREAD;
7588 				} else {
7589 					flag = FWRITE;
7590 				}
7591 
7592 				if ((error = falloc_exec(p, imgp->ip_vfs_context,
7593 				    &fp, &indx)) != 0) {
7594 					continue;
7595 				}
7596 
7597 				ndp = kalloc_type(struct nameidata,
7598 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
7599 
7600 				NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
7601 				    CAST_USER_ADDR_T("/dev/null"),
7602 				    imgp->ip_vfs_context);
7603 
7604 				if ((error = vn_open(ndp, flag, 0)) != 0) {
7605 					fp_free(p, indx, fp);
7606 					kfree_type(struct nameidata, ndp);
7607 					break;
7608 				}
7609 
7610 				struct fileglob *fg = fp->fp_glob;
7611 
7612 				fg->fg_flag = flag;
7613 				fg->fg_ops = &vnops;
7614 				fp_set_data(fp, ndp->ni_vp);
7615 
7616 				vnode_put(ndp->ni_vp);
7617 
7618 				proc_fdlock(p);
7619 				procfdtbl_releasefd(p, indx, NULL);
7620 				fp_drop(p, indx, fp, 1);
7621 				proc_fdunlock(p);
7622 
7623 				kfree_type(struct nameidata, ndp);
7624 			}
7625 		}
7626 	}
7627 #if CONFIG_MACF
7628 	else {
7629 		/*
7630 		 * We are here because we were told that the MAC label will
7631 		 * be transitioned, and the binary is not VSUID or VSGID; to
7632 		 * deal with this case, we could either duplicate a lot of
7633 		 * code, or we can indicate we want to default the P_SUGID
7634 		 * bit clear and jump back up.
7635 		 */
7636 		if (mac_transition) {
7637 			leave_sugid_clear = 1;
7638 			goto handle_mac_transition;
7639 		}
7640 	}
7641 
7642 #endif  /* CONFIG_MACF */
7643 
7644 	/* Update the process' identity version and set the security token.
7645 	 * Also, ensure we always see a modified identity version (rdar://129775819).
7646 	 */
7647 	int previous_pid_version = proc_get_ro(p)->p_idversion;
7648 	int new_pid_version;
7649 	do {
7650 		new_pid_version = OSIncrementAtomic(&nextpidversion);
7651 	} while (new_pid_version == previous_pid_version);
7652 	proc_setpidversion(p, new_pid_version);
7653 	task_set_uniqueid(proc_task(p));
7654 
7655 	/*
7656 	 * Implement the semantic where the effective user and group become
7657 	 * the saved user and group in exec'ed programs.
7658 	 */
7659 	kauth_cred_proc_update(p, PROC_SETTOKEN_ALWAYS,
7660 	    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
7661 		posix_cred_t pcred = posix_cred_get(model);
7662 
7663 		if (pcred->cr_svuid == pcred->cr_uid &&
7664 		pcred->cr_svgid == pcred->cr_gid) {
7665 		        return false;
7666 		}
7667 
7668 		pcred->cr_svuid = pcred->cr_uid;
7669 		pcred->cr_svgid = pcred->cr_gid;
7670 		return true;
7671 	});
7672 
7673 	return error;
7674 }
7675 
7676 
7677 /*
7678  * create_unix_stack
7679  *
7680  * Description:	Set the user stack address for the process to the provided
7681  *		address.  If a custom stack was not set as a result of the
7682  *		load process (i.e. as specified by the image file for the
7683  *		executable), then allocate the stack in the provided map and
7684  *		set up appropriate guard pages for enforcing administrative
7685  *		limits on stack growth, if they end up being needed.
7686  *
7687  * Parameters:	p			Process to set stack on
7688  *		load_result		Information from mach-o load commands
7689  *		map			Address map in which to allocate the new stack
7690  *
7691  * Returns:	KERN_SUCCESS		Stack successfully created
7692  *		!KERN_SUCCESS		Mach failure code
7693  */
7694 __attribute__((noinline))
7695 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)7696 create_unix_stack(vm_map_t map, load_result_t* load_result,
7697     proc_t p)
7698 {
7699 	mach_vm_size_t          size, prot_size;
7700 	mach_vm_offset_t        addr, prot_addr;
7701 	kern_return_t           kr;
7702 
7703 	mach_vm_address_t       user_stack = load_result->user_stack;
7704 
7705 	proc_lock(p);
7706 	p->user_stack = (uintptr_t)user_stack;
7707 	if (load_result->custom_stack) {
7708 		p->p_lflag |= P_LCUSTOM_STACK;
7709 	}
7710 	proc_unlock(p);
7711 	if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
7712 		DEBUG4K_LOAD("map %p user_stack 0x%llx custom %d user_stack_alloc_size 0x%llx\n", map, user_stack, load_result->custom_stack, load_result->user_stack_alloc_size);
7713 	}
7714 
7715 	if (load_result->user_stack_alloc_size > 0) {
7716 		/*
7717 		 * Allocate enough space for the maximum stack size we
7718 		 * will ever authorize and an extra page to act as
7719 		 * a guard page for stack overflows. For default stacks,
7720 		 * vm_initial_limit_stack takes care of the extra guard page.
7721 		 * Otherwise we must allocate it ourselves.
7722 		 */
7723 		if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
7724 			return KERN_INVALID_ARGUMENT;
7725 		}
7726 		addr = vm_map_trunc_page(load_result->user_stack - size,
7727 		    vm_map_page_mask(map));
7728 		kr = mach_vm_allocate_kernel(map, &addr, size,
7729 		    VM_MAP_KERNEL_FLAGS_FIXED(.vm_tag = VM_MEMORY_STACK));
7730 		if (kr != KERN_SUCCESS) {
7731 			// Can't allocate at default location, try anywhere
7732 			addr = 0;
7733 			kr = mach_vm_allocate_kernel(map, &addr, size,
7734 			    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vm_tag = VM_MEMORY_STACK));
7735 			if (kr != KERN_SUCCESS) {
7736 				return kr;
7737 			}
7738 
7739 			user_stack = addr + size;
7740 			load_result->user_stack = (user_addr_t)user_stack;
7741 
7742 			proc_lock(p);
7743 			p->user_stack = (uintptr_t)user_stack;
7744 			proc_unlock(p);
7745 		}
7746 
7747 		load_result->user_stack_alloc = (user_addr_t)addr;
7748 
7749 		/*
7750 		 * And prevent access to what's above the current stack
7751 		 * size limit for this process.
7752 		 */
7753 		if (load_result->user_stack_size == 0) {
7754 			load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
7755 			prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
7756 		} else {
7757 			prot_size = PAGE_SIZE;
7758 		}
7759 
7760 		prot_addr = addr;
7761 		kr = mach_vm_protect(map,
7762 		    prot_addr,
7763 		    prot_size,
7764 		    FALSE,
7765 		    VM_PROT_NONE);
7766 		if (kr != KERN_SUCCESS) {
7767 			(void)mach_vm_deallocate(map, addr, size);
7768 			return kr;
7769 		}
7770 	}
7771 
7772 	return KERN_SUCCESS;
7773 }
7774 
7775 #include <sys/reboot.h>
7776 
7777 /*
7778  * load_init_program_at_path
7779  *
7780  * Description:	Load the "init" program; in most cases, this will be "launchd"
7781  *
7782  * Parameters:	p			Process to call execve() to create
7783  *					the "init" program
7784  *		scratch_addr		Page in p, scratch space
7785  *		path			NULL terminated path
7786  *
7787  * Returns:	KERN_SUCCESS		Success
7788  *		!KERN_SUCCESS           See execve/mac_execve for error codes
7789  *
7790  * Notes:	The process that is passed in is the first manufactured
7791  *		process on the system, and gets here via bsd_ast() firing
7792  *		for the first time.  This is done to ensure that bsd_init()
7793  *		has run to completion.
7794  *
7795  *		The address map of the first manufactured process matches the
7796  *		word width of the kernel. Once the self-exec completes, the
7797  *		initproc might be different.
7798  */
7799 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)7800 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
7801 {
7802 	int retval[2];
7803 	int error;
7804 	struct execve_args init_exec_args;
7805 	user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
7806 
7807 	/*
7808 	 * Validate inputs and pre-conditions
7809 	 */
7810 	assert(p);
7811 	assert(scratch_addr);
7812 	assert(path);
7813 
7814 	/*
7815 	 * Copy out program name.
7816 	 */
7817 	size_t path_length = strlen(path) + 1;
7818 	argv0 = scratch_addr;
7819 	error = copyout(path, argv0, path_length);
7820 	if (error) {
7821 		return error;
7822 	}
7823 
7824 	scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
7825 
7826 	/*
7827 	 * Put out first (and only) argument, similarly.
7828 	 * Assumes everything fits in a page as allocated above.
7829 	 */
7830 	if (boothowto & RB_SINGLE) {
7831 		const char *init_args = "-s";
7832 		size_t init_args_length = strlen(init_args) + 1;
7833 
7834 		argv1 = scratch_addr;
7835 		error = copyout(init_args, argv1, init_args_length);
7836 		if (error) {
7837 			return error;
7838 		}
7839 
7840 		scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
7841 	}
7842 
7843 	if (proc_is64bit(p)) {
7844 		user64_addr_t argv64bit[3] = {};
7845 
7846 		argv64bit[0] = argv0;
7847 		argv64bit[1] = argv1;
7848 		argv64bit[2] = USER_ADDR_NULL;
7849 
7850 		error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
7851 		if (error) {
7852 			return error;
7853 		}
7854 	} else {
7855 		user32_addr_t argv32bit[3] = {};
7856 
7857 		argv32bit[0] = (user32_addr_t)argv0;
7858 		argv32bit[1] = (user32_addr_t)argv1;
7859 		argv32bit[2] = USER_ADDR_NULL;
7860 
7861 		error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
7862 		if (error) {
7863 			return error;
7864 		}
7865 	}
7866 
7867 	/*
7868 	 * Set up argument block for fake call to execve.
7869 	 */
7870 	init_exec_args.fname = argv0;
7871 	init_exec_args.argp = scratch_addr;
7872 	init_exec_args.envp = USER_ADDR_NULL;
7873 
7874 	/*
7875 	 * So that init task is set with uid,gid 0 token
7876 	 *
7877 	 * The access to the cred is safe:
7878 	 * the proc isn't running yet, it's stable.
7879 	 */
7880 	set_security_token(p, proc_ucred_unsafe(p));
7881 
7882 	return execve(p, &init_exec_args, retval);
7883 }
7884 
7885 static const char * init_programs[] = {
7886 #if DEBUG
7887 	"/usr/appleinternal/sbin/launchd.debug",
7888 #endif
7889 #if DEVELOPMENT || DEBUG
7890 	"/usr/appleinternal/sbin/launchd.development",
7891 #endif
7892 	"/sbin/launchd",
7893 };
7894 
7895 /*
7896  * load_init_program
7897  *
7898  * Description:	Load the "init" program; in most cases, this will be "launchd"
7899  *
7900  * Parameters:	p			Process to call execve() to create
7901  *					the "init" program
7902  *
7903  * Returns:	(void)
7904  *
7905  * Notes:	The process that is passed in is the first manufactured
7906  *		process on the system, and gets here via bsd_ast() firing
7907  *		for the first time.  This is done to ensure that bsd_init()
7908  *		has run to completion.
7909  *
7910  *		In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
7911  *		may be used to select a specific launchd executable. As with
7912  *		the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
7913  *		will force /sbin/launchd to be selected.
7914  *
7915  *              Search order by build:
7916  *
7917  * DEBUG	DEVELOPMENT	RELEASE		PATH
7918  * ----------------------------------------------------------------------------------
7919  * 1		1		NA		/usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
7920  * 2		NA		NA		/usr/appleinternal/sbin/launchd.debug
7921  * 3		2		NA		/usr/appleinternal/sbin/launchd.development
7922  * 4		3		1		/sbin/launchd
7923  */
7924 void
load_init_program(proc_t p)7925 load_init_program(proc_t p)
7926 {
7927 	uint32_t i;
7928 	int error;
7929 	vm_map_t map = current_map();
7930 	mach_vm_offset_t scratch_addr = 0;
7931 	mach_vm_size_t map_page_size = vm_map_page_size(map);
7932 
7933 #if DEVELOPMENT || DEBUG
7934 	/* Use the opportunity to initialize exec's debug log stream */
7935 	exec_log_handle = os_log_create("com.apple.xnu.bsd", "exec");
7936 #endif /* DEVELOPMENT || DEBUG */
7937 
7938 	(void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size,
7939 	    VM_MAP_KERNEL_FLAGS_ANYWHERE());
7940 #if CONFIG_MEMORYSTATUS
7941 	(void) memorystatus_init_at_boot_snapshot();
7942 #endif /* CONFIG_MEMORYSTATUS */
7943 
7944 #if DEBUG || DEVELOPMENT
7945 	/* Check for boot-arg suffix first */
7946 	char launchd_suffix[64];
7947 	if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
7948 		char launchd_path[128];
7949 		boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
7950 		    (strcmp(launchd_suffix, "release") == 0));
7951 
7952 		if (is_release_suffix) {
7953 			printf("load_init_program: attempting to load /sbin/launchd\n");
7954 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
7955 			if (!error) {
7956 				return;
7957 			}
7958 
7959 			panic("Process 1 exec of launchd.release failed, errno %d", error);
7960 		} else {
7961 			strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
7962 			strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
7963 
7964 			printf("load_init_program: attempting to load %s\n", launchd_path);
7965 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
7966 			if (!error) {
7967 				return;
7968 			} else if (error != ENOENT) {
7969 				printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
7970 			}
7971 		}
7972 	}
7973 #endif
7974 
7975 	error = ENOENT;
7976 	for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
7977 		printf("load_init_program: attempting to load %s\n", init_programs[i]);
7978 		error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
7979 		if (!error) {
7980 			return;
7981 		} else if (error != ENOENT) {
7982 			printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
7983 		}
7984 	}
7985 
7986 	panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
7987 }
7988 
7989 /*
7990  * load_return_to_errno
7991  *
7992  * Description:	Convert a load_return_t (Mach error) to an errno (BSD error)
7993  *
7994  * Parameters:	lrtn			Mach error number
7995  *
7996  * Returns:	(int)			BSD error number
7997  *		0			Success
7998  *		EBADARCH		Bad architecture
7999  *		EBADMACHO		Bad Mach object file
8000  *		ESHLIBVERS		Bad shared library version
8001  *		ENOMEM			Out of memory/resource shortage
8002  *		EACCES			Access denied
8003  *		ENOENT			Entry not found (usually "file does
8004  *					does not exist")
8005  *		EIO			An I/O error occurred
8006  *		EBADEXEC		The executable is corrupt/unknown
8007  */
8008 static int
load_return_to_errno(load_return_t lrtn)8009 load_return_to_errno(load_return_t lrtn)
8010 {
8011 	switch (lrtn) {
8012 	case LOAD_SUCCESS:
8013 		return 0;
8014 	case LOAD_BADARCH:
8015 		return EBADARCH;
8016 	case LOAD_BADMACHO:
8017 	case LOAD_BADMACHO_UPX:
8018 		return EBADMACHO;
8019 	case LOAD_SHLIB:
8020 		return ESHLIBVERS;
8021 	case LOAD_NOSPACE:
8022 	case LOAD_RESOURCE:
8023 		return ENOMEM;
8024 	case LOAD_PROTECT:
8025 		return EACCES;
8026 	case LOAD_ENOENT:
8027 		return ENOENT;
8028 	case LOAD_IOERROR:
8029 		return EIO;
8030 	case LOAD_DECRYPTFAIL:
8031 		return EAUTH;
8032 	case LOAD_FAILURE:
8033 	default:
8034 		return EBADEXEC;
8035 	}
8036 }
8037 
8038 #include <mach/mach_types.h>
8039 #include <mach/vm_prot.h>
8040 #include <mach/semaphore.h>
8041 #include <mach/sync_policy.h>
8042 #include <kern/clock.h>
8043 #include <mach/kern_return.h>
8044 
8045 /*
8046  * execargs_alloc
8047  *
8048  * Description:	Allocate the block of memory used by the execve arguments.
8049  *		At the same time, we allocate a page so that we can read in
8050  *		the first page of the image.
8051  *
8052  * Parameters:	struct image_params *	the image parameter block
8053  *
8054  * Returns:	0			Success
8055  *		EINVAL			Invalid argument
8056  *		EACCES			Permission denied
8057  *		EINTR			Interrupted function
8058  *		ENOMEM			Not enough space
8059  *
8060  * Notes:	This is a temporary allocation into the kernel address space
8061  *		to enable us to copy arguments in from user space.  This is
8062  *		necessitated by not mapping the process calling execve() into
8063  *		the kernel address space during the execve() system call.
8064  *
8065  *		We assemble the argument and environment, etc., into this
8066  *		region before copying it as a single block into the child
8067  *		process address space (at the top or bottom of the stack,
8068  *		depending on which way the stack grows; see the function
8069  *		exec_copyout_strings() for details).
8070  *
8071  *		This ends up with a second (possibly unnecessary) copy compared
8072  *		with assembing the data directly into the child address space,
8073  *		instead, but since we cannot be guaranteed that the parent has
8074  *		not modified its environment, we can't really know that it's
8075  *		really a block there as well.
8076  */
8077 
8078 
8079 static int execargs_waiters = 0;
8080 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
8081 
8082 static void
execargs_lock_lock(void)8083 execargs_lock_lock(void)
8084 {
8085 	lck_mtx_lock_spin(&execargs_cache_lock);
8086 }
8087 
8088 static void
execargs_lock_unlock(void)8089 execargs_lock_unlock(void)
8090 {
8091 	lck_mtx_unlock(&execargs_cache_lock);
8092 }
8093 
8094 static wait_result_t
execargs_lock_sleep(void)8095 execargs_lock_sleep(void)
8096 {
8097 	return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
8098 }
8099 
8100 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)8101 execargs_purgeable_allocate(char **execarg_address)
8102 {
8103 	mach_vm_offset_t addr = 0;
8104 	kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
8105 	    BSD_PAGEABLE_SIZE_PER_EXEC,
8106 	    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vmf_purgeable = true));
8107 	*execarg_address = (char *)addr;
8108 	assert(kr == KERN_SUCCESS);
8109 	return kr;
8110 }
8111 
8112 static kern_return_t
execargs_purgeable_reference(void * execarg_address)8113 execargs_purgeable_reference(void *execarg_address)
8114 {
8115 	int state = VM_PURGABLE_NONVOLATILE;
8116 	kern_return_t kr = vm_map_purgable_control(bsd_pageable_map,
8117 	    (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
8118 
8119 	assert(kr == KERN_SUCCESS);
8120 	return kr;
8121 }
8122 
8123 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)8124 execargs_purgeable_volatilize(void *execarg_address)
8125 {
8126 	int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
8127 	kern_return_t kr;
8128 	kr = vm_map_purgable_control(bsd_pageable_map,
8129 	    (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
8130 
8131 	assert(kr == KERN_SUCCESS);
8132 
8133 	return kr;
8134 }
8135 
8136 static void
execargs_wakeup_waiters(void)8137 execargs_wakeup_waiters(void)
8138 {
8139 	thread_wakeup(&execargs_free_count);
8140 }
8141 
8142 static int
execargs_alloc(struct image_params * imgp)8143 execargs_alloc(struct image_params *imgp)
8144 {
8145 	kern_return_t kret;
8146 	wait_result_t res;
8147 	int i, cache_index = -1;
8148 
8149 	execargs_lock_lock();
8150 
8151 	while (execargs_free_count == 0) {
8152 		execargs_waiters++;
8153 		res = execargs_lock_sleep();
8154 		execargs_waiters--;
8155 		if (res != THREAD_AWAKENED) {
8156 			execargs_lock_unlock();
8157 			return EINTR;
8158 		}
8159 	}
8160 
8161 	execargs_free_count--;
8162 
8163 	for (i = 0; i < execargs_cache_size; i++) {
8164 		vm_offset_t element = execargs_cache[i];
8165 		if (element) {
8166 			cache_index = i;
8167 			imgp->ip_strings = (char *)(execargs_cache[i]);
8168 			execargs_cache[i] = 0;
8169 			break;
8170 		}
8171 	}
8172 
8173 	assert(execargs_free_count >= 0);
8174 
8175 	execargs_lock_unlock();
8176 
8177 	if (cache_index == -1) {
8178 		kret = execargs_purgeable_allocate(&imgp->ip_strings);
8179 	} else {
8180 		kret = execargs_purgeable_reference(imgp->ip_strings);
8181 	}
8182 
8183 	assert(kret == KERN_SUCCESS);
8184 	if (kret != KERN_SUCCESS) {
8185 		return ENOMEM;
8186 	}
8187 
8188 	/* last page used to read in file headers */
8189 	imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
8190 	imgp->ip_strendp = imgp->ip_strings;
8191 	imgp->ip_argspace = NCARGS;
8192 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
8193 
8194 	return 0;
8195 }
8196 
8197 /*
8198  * execargs_free
8199  *
8200  * Description:	Free the block of memory used by the execve arguments and the
8201  *		first page of the executable by a previous call to the function
8202  *		execargs_alloc().
8203  *
8204  * Parameters:	struct image_params *	the image parameter block
8205  *
8206  * Returns:	0			Success
8207  *		EINVAL			Invalid argument
8208  *		EINTR			Oeration interrupted
8209  */
8210 static int
execargs_free(struct image_params * imgp)8211 execargs_free(struct image_params *imgp)
8212 {
8213 	kern_return_t kret;
8214 	int i;
8215 	boolean_t needs_wakeup = FALSE;
8216 
8217 	kret = execargs_purgeable_volatilize(imgp->ip_strings);
8218 
8219 	execargs_lock_lock();
8220 	execargs_free_count++;
8221 
8222 	for (i = 0; i < execargs_cache_size; i++) {
8223 		vm_offset_t element = execargs_cache[i];
8224 		if (element == 0) {
8225 			execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
8226 			imgp->ip_strings = NULL;
8227 			break;
8228 		}
8229 	}
8230 
8231 	assert(imgp->ip_strings == NULL);
8232 
8233 	if (execargs_waiters > 0) {
8234 		needs_wakeup = TRUE;
8235 	}
8236 
8237 	execargs_lock_unlock();
8238 
8239 	if (needs_wakeup == TRUE) {
8240 		execargs_wakeup_waiters();
8241 	}
8242 
8243 	return kret == KERN_SUCCESS ? 0 : EINVAL;
8244 }
8245 
8246 void
uthread_set_exec_data(struct uthread * uth,struct image_params * imgp)8247 uthread_set_exec_data(struct uthread *uth, struct image_params *imgp)
8248 {
8249 	uth->uu_save.uus_exec_data.imgp = imgp;
8250 }
8251 
8252 size_t
thread_get_current_exec_path(char * path,size_t size)8253 thread_get_current_exec_path(char *path, size_t size)
8254 {
8255 	struct uthread *uth = current_uthread();
8256 	struct image_params *imgp = uth->uu_save.uus_exec_data.imgp;
8257 	size_t string_size = 0;
8258 	char *exec_path;
8259 
8260 	if (path == NULL || imgp == NULL || imgp->ip_strings == NULL) {
8261 		return 0;
8262 	}
8263 
8264 	exec_path = imgp->ip_strings + strlen(EXECUTABLE_KEY);
8265 	string_size = imgp->ip_strendp - exec_path;
8266 	string_size = MIN(MAXPATHLEN, string_size);
8267 	string_size = MIN(size, string_size);
8268 
8269 	string_size = strlcpy(path, exec_path, string_size);
8270 	return string_size;
8271 }
8272 static void
exec_resettextvp(proc_t p,struct image_params * imgp)8273 exec_resettextvp(proc_t p, struct image_params *imgp)
8274 {
8275 	vnode_t vp;
8276 	off_t offset;
8277 	vnode_t tvp  = p->p_textvp;
8278 	int ret;
8279 
8280 	vp = imgp->ip_vp;
8281 	offset = imgp->ip_arch_offset;
8282 
8283 	if (vp == NULLVP) {
8284 		panic("exec_resettextvp: expected valid vp");
8285 	}
8286 
8287 	ret = vnode_ref(vp);
8288 	proc_lock(p);
8289 	if (ret == 0) {
8290 		p->p_textvp = vp;
8291 		p->p_textoff = offset;
8292 	} else {
8293 		p->p_textvp = NULLVP;   /* this is paranoia */
8294 		p->p_textoff = 0;
8295 	}
8296 	proc_unlock(p);
8297 
8298 	if (tvp != NULLVP) {
8299 		if (vnode_getwithref(tvp) == 0) {
8300 			vnode_rele(tvp);
8301 			vnode_put(tvp);
8302 		}
8303 	}
8304 }
8305 
8306 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
8307 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
8308 
8309 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)8310 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
8311 {
8312 	static char const nibble[] = "0123456789abcdef";
8313 
8314 	/* Apparently still the safest way to get a hex representation
8315 	 * of binary data.
8316 	 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
8317 	 * <rdar://problem/33328859> confusion around %*D/%nD in printf
8318 	 */
8319 	for (int i = 0; i < CS_CDHASH_LEN; ++i) {
8320 		str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
8321 		str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
8322 	}
8323 	str[CS_CDHASH_STRING_SIZE - 1] = 0;
8324 }
8325 
8326 /*
8327  * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
8328  *
8329  * Description: Waits for the userspace daemon to respond to the request
8330  *              we made. Function declared non inline to be visible in
8331  *		stackshots and spindumps as well as debugging.
8332  */
8333 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)8334 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
8335 {
8336 	return find_code_signature(task_access_port, new_pid);
8337 }
8338 
8339 /*
8340  * Update signature dependent process state, called by
8341  * process_signature.
8342  */
8343 static int
proc_process_signature(proc_t p,os_reason_t * signature_failure_reason)8344 proc_process_signature(proc_t p, os_reason_t *signature_failure_reason)
8345 {
8346 	int error = 0;
8347 	char const *error_msg = NULL;
8348 
8349 	kern_return_t kr = machine_task_process_signature(proc_get_task_raw(p), proc_platform(p), proc_sdk(p), &error_msg);
8350 
8351 	if (kr != KERN_SUCCESS) {
8352 		error = EINVAL;
8353 
8354 		if (error_msg != NULL) {
8355 			uint32_t error_msg_len = (uint32_t)strlen(error_msg) + 1;
8356 			mach_vm_address_t data_addr = 0;
8357 			int reason_error = 0;
8358 			int kcdata_error = 0;
8359 
8360 			os_reason_t reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
8361 			reason->osr_flags = OS_REASON_FLAG_GENERATE_CRASH_REPORT | OS_REASON_FLAG_CONSISTENT_FAILURE;
8362 
8363 			if ((reason_error = os_reason_alloc_buffer_noblock(reason,
8364 			    kcdata_estimate_required_buffer_size(1, error_msg_len))) == 0 &&
8365 			    (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
8366 			    EXIT_REASON_USER_DESC, error_msg_len,
8367 			    &data_addr)) == KERN_SUCCESS) {
8368 				kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
8369 				    error_msg, error_msg_len);
8370 
8371 				if (mc_error != KERN_SUCCESS) {
8372 					printf("process_signature: failed to copy reason string (kcdata_memcpy error: %d)\n",
8373 					    mc_error);
8374 				}
8375 			} else {
8376 				printf("failed to allocate space for reason string (os_reason_alloc_buffer error: %d, kcdata error: %d, length: %u)\n",
8377 				    reason_error, kcdata_error, error_msg_len);
8378 			}
8379 
8380 			assert(*signature_failure_reason == NULL); // shouldn't have gotten so far
8381 			*signature_failure_reason = reason;
8382 		}
8383 	}
8384 	return error;
8385 }
8386 
8387 
8388 #define DT_UNRESTRICTED_SUBSYSTEM_ROOT "unrestricted-subsystem-root"
8389 
8390 static bool
allow_unrestricted_subsystem_root(void)8391 allow_unrestricted_subsystem_root(void)
8392 {
8393 #if !(DEVELOPMENT || DEBUG)
8394 	static bool allow_unrestricted_subsystem_root = false;
8395 	static bool has_been_set = false;
8396 
8397 	if (!has_been_set) {
8398 		DTEntry chosen;
8399 		const uint32_t *value;
8400 		unsigned size;
8401 
8402 		has_been_set = true;
8403 		if (SecureDTLookupEntry(0, "/chosen", &chosen) == kSuccess &&
8404 		    SecureDTGetProperty(chosen, DT_UNRESTRICTED_SUBSYSTEM_ROOT, (const void**)&value, &size) == kSuccess &&
8405 		    value != NULL &&
8406 		    size == sizeof(uint32_t)) {
8407 			allow_unrestricted_subsystem_root = (bool)*value;
8408 		}
8409 	}
8410 
8411 	return allow_unrestricted_subsystem_root;
8412 #else
8413 	return true;
8414 #endif
8415 }
8416 
8417 static int
process_signature(proc_t p,struct image_params * imgp)8418 process_signature(proc_t p, struct image_params *imgp)
8419 {
8420 	mach_port_t port = IPC_PORT_NULL;
8421 	kern_return_t kr = KERN_FAILURE;
8422 	int error = EACCES;
8423 	boolean_t unexpected_failure = FALSE;
8424 	struct cs_blob *csb;
8425 	boolean_t require_success = FALSE;
8426 	int spawn = (imgp->ip_flags & IMGPF_SPAWN);
8427 	const int vfexec = 0;
8428 	os_reason_t signature_failure_reason = OS_REASON_NULL;
8429 
8430 	/*
8431 	 * Override inherited code signing flags with the
8432 	 * ones for the process that is being successfully
8433 	 * loaded
8434 	 */
8435 	proc_lock(p);
8436 	proc_csflags_update(p, imgp->ip_csflags);
8437 	proc_unlock(p);
8438 
8439 	/* Set the switch_protect flag on the map */
8440 	if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
8441 		vm_map_switch_protect(get_task_map(proc_task(p)), TRUE);
8442 	}
8443 	/* set the cs_enforced flags in the map */
8444 	if (proc_getcsflags(p) & CS_ENFORCEMENT) {
8445 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), TRUE);
8446 	} else {
8447 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), FALSE);
8448 	}
8449 
8450 	/*
8451 	 * image activation may be failed due to policy
8452 	 * which is unexpected but security framework does not
8453 	 * approve of exec, kill and return immediately.
8454 	 */
8455 	if (imgp->ip_mac_return != 0) {
8456 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
8457 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
8458 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
8459 		error = imgp->ip_mac_return;
8460 		unexpected_failure = TRUE;
8461 		goto done;
8462 	}
8463 
8464 	if (imgp->ip_cs_error != OS_REASON_NULL) {
8465 		signature_failure_reason = imgp->ip_cs_error;
8466 		imgp->ip_cs_error = OS_REASON_NULL;
8467 		error = EACCES;
8468 		goto done;
8469 	}
8470 
8471 	/* call the launch constraints hook */
8472 	os_reason_t launch_constraint_reason;
8473 	if ((error = mac_proc_check_launch_constraints(p, imgp, &launch_constraint_reason)) != 0) {
8474 		signature_failure_reason = launch_constraint_reason;
8475 		goto done;
8476 	}
8477 
8478 	/*
8479 	 * Reject when there's subsystem root path set, but the image is restricted, and doesn't require
8480 	 * library validation. This is to avoid subsystem root being used to inject unsigned code
8481 	 */
8482 	if (!allow_unrestricted_subsystem_root()) {
8483 		if ((imgp->ip_csflags & CS_RESTRICT || proc_issetugid(p)) &&
8484 		    !(imgp->ip_csflags & CS_REQUIRE_LV) &&
8485 		    (imgp->ip_subsystem_root_path != NULL)) {
8486 			signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
8487 			error = EACCES;
8488 			goto done;
8489 		}
8490 	}
8491 
8492 #if XNU_TARGET_OS_OSX
8493 	/* Check for platform passed in spawn attr if iOS binary is being spawned */
8494 	if (proc_platform(p) == PLATFORM_IOS) {
8495 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
8496 		if (psa == NULL || psa->psa_platform == 0) {
8497 			boolean_t no_sandbox_entitled = FALSE;
8498 #if DEBUG || DEVELOPMENT
8499 			/*
8500 			 * Allow iOS binaries to spawn on internal systems
8501 			 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
8502 			 * boot-arg set to true
8503 			 */
8504 			if (unentitled_ios_sim_launch) {
8505 				no_sandbox_entitled = TRUE;
8506 			} else {
8507 				no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
8508 				    (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
8509 			}
8510 #endif /* DEBUG || DEVELOPMENT */
8511 			if (!no_sandbox_entitled) {
8512 				signature_failure_reason = os_reason_create(OS_REASON_EXEC,
8513 				    EXEC_EXIT_REASON_WRONG_PLATFORM);
8514 				error = EACCES;
8515 				goto done;
8516 			}
8517 			printf("Allowing spawn of iOS binary %s since it has "
8518 			    "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
8519 			    "boot-arg set to true\n", p->p_name);
8520 		} else if (psa->psa_platform != PLATFORM_IOS) {
8521 			/* Simulator binary spawned with wrong platform */
8522 			signature_failure_reason = os_reason_create(OS_REASON_EXEC,
8523 			    EXEC_EXIT_REASON_WRONG_PLATFORM);
8524 			error = EACCES;
8525 			goto done;
8526 		} else {
8527 			printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
8528 			    p->p_name);
8529 		}
8530 	}
8531 #endif /* XNU_TARGET_OS_OSX */
8532 
8533 	/* If the code signature came through the image activation path, we skip the
8534 	 * taskgated / externally attached path. */
8535 	if (imgp->ip_csflags & CS_SIGNED) {
8536 		error = 0;
8537 		goto done;
8538 	}
8539 
8540 	/* The rest of the code is for signatures that either already have been externally
8541 	 * attached (likely, but not necessarily by a previous run through the taskgated
8542 	 * path), or that will now be attached by taskgated. */
8543 
8544 	kr = task_get_task_access_port(proc_task(p), &port);
8545 	if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
8546 		error = 0;
8547 		if (require_success) {
8548 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
8549 			    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
8550 			signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
8551 			error = EACCES;
8552 		}
8553 		goto done;
8554 	}
8555 
8556 	/*
8557 	 * taskgated returns KERN_SUCCESS if it has completed its work
8558 	 * and the exec should continue, KERN_FAILURE if the exec should
8559 	 * fail, or it may error out with different error code in an
8560 	 * event of mig failure (e.g. process was signalled during the
8561 	 * rpc call, taskgated died, mig server died etc.).
8562 	 */
8563 
8564 	kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
8565 	switch (kr) {
8566 	case KERN_SUCCESS:
8567 		error = 0;
8568 		break;
8569 	case KERN_FAILURE:
8570 		error = EACCES;
8571 
8572 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
8573 		    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
8574 		signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
8575 		goto done;
8576 	default:
8577 		error = EACCES;
8578 
8579 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
8580 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
8581 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
8582 		unexpected_failure = TRUE;
8583 		goto done;
8584 	}
8585 
8586 	/* Only do this if exec_resettextvp() did not fail */
8587 	if (p->p_textvp != NULLVP) {
8588 		csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
8589 
8590 		if (csb != NULL) {
8591 			/* As the enforcement we can do here is very limited, we only allow things that
8592 			 * are the only reason why this code path still exists:
8593 			 * Adhoc signed non-platform binaries without special cs_flags and without any
8594 			 * entitlements (unrestricted ones still pass AMFI). */
8595 			if (
8596 				/* Revalidate the blob if necessary through bumped generation count. */
8597 				(ubc_cs_generation_check(p->p_textvp) == 0 ||
8598 				ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
8599 				/* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
8600 				(csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
8601 				/* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
8602 				csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
8603 				CSSLOT_SIGNATURESLOT,
8604 				CSMAGIC_BLOBWRAPPER) == NULL &&
8605 				/* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
8606 				csb->csb_platform_binary == 0 &&
8607 				/* No entitlements, not even unrestricted ones. */
8608 				csb->csb_entitlements_blob == NULL &&
8609 				csb->csb_der_entitlements_blob == NULL) {
8610 				proc_lock(p);
8611 				proc_csflags_set(p, CS_SIGNED | CS_VALID);
8612 				proc_unlock(p);
8613 			} else {
8614 				uint8_t cdhash[CS_CDHASH_LEN];
8615 				char cdhash_string[CS_CDHASH_STRING_SIZE];
8616 				proc_getcdhash(p, cdhash);
8617 				cdhash_to_string(cdhash_string, cdhash);
8618 				printf("ignoring detached code signature on '%s' with cdhash '%s' "
8619 				    "because it is invalid, or not a simple adhoc signature.\n",
8620 				    p->p_name, cdhash_string);
8621 			}
8622 		}
8623 	}
8624 
8625 done:
8626 	if (0 == error) {
8627 		/*
8628 		 * Update the new process's signature-dependent process state.
8629 		 * state.
8630 		 */
8631 
8632 		error = proc_process_signature(p, &signature_failure_reason);
8633 	}
8634 
8635 	if (0 == error) {
8636 		/*
8637 		 * Update the new main thread's signature-dependent thread
8638 		 * state. This was also called when the thread was created,
8639 		 * but for the main thread the signature was not yet attached
8640 		 * at that time.
8641 		 */
8642 		kr = thread_process_signature(imgp->ip_new_thread, proc_get_task_raw(p));
8643 
8644 		if (kr != KERN_SUCCESS) {
8645 			error = EINVAL;
8646 			signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MACHINE_THREAD);
8647 		}
8648 	}
8649 
8650 	if (0 == error) {
8651 		/* The process's code signature related properties are
8652 		 * fully set up, so this is an opportune moment to log
8653 		 * platform binary execution, if desired. */
8654 		if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
8655 			uint8_t cdhash[CS_CDHASH_LEN];
8656 			char cdhash_string[CS_CDHASH_STRING_SIZE];
8657 			proc_getcdhash(p, cdhash);
8658 			cdhash_to_string(cdhash_string, cdhash);
8659 
8660 			os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
8661 			    "'%s' with cdhash %s\n", p->p_name, cdhash_string);
8662 		}
8663 	} else {
8664 		if (!unexpected_failure) {
8665 			proc_csflags_set(p, CS_KILLED);
8666 		}
8667 		/* make very sure execution fails */
8668 		if (vfexec || spawn) {
8669 			assert(signature_failure_reason != OS_REASON_NULL);
8670 			psignal_vfork_with_reason(p, proc_task(p), imgp->ip_new_thread,
8671 			    SIGKILL, signature_failure_reason);
8672 			signature_failure_reason = OS_REASON_NULL;
8673 			error = 0;
8674 		} else {
8675 			assert(signature_failure_reason != OS_REASON_NULL);
8676 			psignal_with_reason(p, SIGKILL, signature_failure_reason);
8677 			signature_failure_reason = OS_REASON_NULL;
8678 		}
8679 	}
8680 
8681 	if (port != IPC_PORT_NULL) {
8682 		ipc_port_release_send(port);
8683 	}
8684 
8685 	/* If we hit this, we likely would have leaked an exit reason */
8686 	assert(signature_failure_reason == OS_REASON_NULL);
8687 	return error;
8688 }
8689 
8690 /*
8691  * Typically as soon as we start executing this process, the
8692  * first instruction will trigger a VM fault to bring the text
8693  * pages (as executable) into the address space, followed soon
8694  * thereafter by dyld data structures (for dynamic executable).
8695  * To optimize this, as well as improve support for hardware
8696  * debuggers that can only access resident pages present
8697  * in the process' page tables, we prefault some pages if
8698  * possible. Errors are non-fatal.
8699  */
8700 #ifndef PREVENT_CALLER_STACK_USE
8701 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
8702 #endif
8703 
8704 /*
8705  * Prefaulting dyld data does not work (rdar://76621401)
8706  */
8707 #define FIXED_76621401 0
8708 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(__unused proc_t p,__unused struct image_params * imgp,__unused load_result_t * load_result)8709 exec_prefault_data(
8710 	__unused proc_t p,
8711 	__unused struct image_params *imgp,
8712 	__unused load_result_t *load_result)
8713 {
8714 #if FIXED_76621401
8715 	int ret;
8716 	size_t expected_all_image_infos_size;
8717 #endif /* FIXED_76621401 */
8718 	kern_return_t kr;
8719 
8720 	/*
8721 	 * Prefault executable or dyld entry point.
8722 	 */
8723 	if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8724 		DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
8725 	}
8726 	kr = vm_fault(current_map(),
8727 	    vm_map_trunc_page(load_result->entry_point,
8728 	    vm_map_page_mask(current_map())),
8729 	    VM_PROT_READ | VM_PROT_EXECUTE,
8730 	    FALSE, VM_KERN_MEMORY_NONE,
8731 	    THREAD_UNINT, NULL, 0);
8732 	if (kr != KERN_SUCCESS) {
8733 		DEBUG4K_ERROR("map %p va 0x%llx -> 0x%x\n", current_map(), (uint64_t)vm_map_trunc_page(load_result->entry_point, vm_map_page_mask(current_map())), kr);
8734 	}
8735 
8736 #if FIXED_76621401
8737 	if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
8738 		expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
8739 	} else {
8740 		expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
8741 	}
8742 
8743 	/* Decode dyld anchor structure from <mach-o/dyld_images.h> */
8744 	if (load_result->dynlinker &&
8745 	    load_result->all_image_info_addr &&
8746 	    load_result->all_image_info_size >= expected_all_image_infos_size) {
8747 		union {
8748 			struct user64_dyld_all_image_infos      infos64;
8749 			struct user32_dyld_all_image_infos      infos32;
8750 		} all_image_infos;
8751 
8752 		/*
8753 		 * Pre-fault to avoid copyin() going through the trap handler
8754 		 * and recovery path.
8755 		 */
8756 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8757 			DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
8758 		}
8759 		kr = vm_fault(current_map(),
8760 		    vm_map_trunc_page(load_result->all_image_info_addr,
8761 		    vm_map_page_mask(current_map())),
8762 		    VM_PROT_READ | VM_PROT_WRITE,
8763 		    FALSE, VM_KERN_MEMORY_NONE,
8764 		    THREAD_UNINT, NULL, 0);
8765 		if (kr != KERN_SUCCESS) {
8766 //			printf("%s:%d map %p va 0x%llx -> 0x%x\n", __FUNCTION__, __LINE__, current_map(), vm_map_trunc_page(load_result->all_image_info_addr, vm_map_page_mask(current_map())), kr);
8767 		}
8768 		if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
8769 			/* all_image_infos straddles a page */
8770 			kr = vm_fault(current_map(),
8771 			    vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
8772 			    vm_map_page_mask(current_map())),
8773 			    VM_PROT_READ | VM_PROT_WRITE,
8774 			    FALSE, VM_KERN_MEMORY_NONE,
8775 			    THREAD_UNINT, NULL, 0);
8776 			if (kr != KERN_SUCCESS) {
8777 //				printf("%s:%d map %p va 0x%llx -> 0x%x\n", __FUNCTION__, __LINE__, current_map(), vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size -1, vm_map_page_mask(current_map())), kr);
8778 			}
8779 		}
8780 
8781 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8782 			DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
8783 		}
8784 		ret = copyin((user_addr_t)load_result->all_image_info_addr,
8785 		    &all_image_infos,
8786 		    expected_all_image_infos_size);
8787 		if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
8788 			user_addr_t notification_address;
8789 			user_addr_t dyld_image_address;
8790 			user_addr_t dyld_version_address;
8791 			user_addr_t dyld_all_image_infos_address;
8792 			user_addr_t dyld_slide_amount;
8793 
8794 			if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
8795 				notification_address = (user_addr_t)all_image_infos.infos64.notification;
8796 				dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
8797 				dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
8798 				dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
8799 			} else {
8800 				notification_address = all_image_infos.infos32.notification;
8801 				dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
8802 				dyld_version_address = all_image_infos.infos32.dyldVersion;
8803 				dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
8804 			}
8805 
8806 			/*
8807 			 * dyld statically sets up the all_image_infos in its Mach-O
8808 			 * binary at static link time, with pointers relative to its default
8809 			 * load address. Since ASLR might slide dyld before its first
8810 			 * instruction is executed, "dyld_slide_amount" tells us how far
8811 			 * dyld was loaded compared to its default expected load address.
8812 			 * All other pointers into dyld's image should be adjusted by this
8813 			 * amount. At some point later, dyld will fix up pointers to take
8814 			 * into account the slide, at which point the all_image_infos_address
8815 			 * field in the structure will match the runtime load address, and
8816 			 * "dyld_slide_amount" will be 0, if we were to consult it again.
8817 			 */
8818 
8819 			dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
8820 
8821 #if 0
8822 			kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
8823 			    (uint64_t)load_result->all_image_info_addr,
8824 			    all_image_infos.infos32.version,
8825 			    (uint64_t)notification_address,
8826 			    (uint64_t)dyld_image_address,
8827 			    (uint64_t)dyld_version_address,
8828 			    (uint64_t)dyld_all_image_infos_address);
8829 #endif
8830 
8831 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8832 				DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
8833 			}
8834 			kr = vm_fault(current_map(),
8835 			    vm_map_trunc_page(notification_address + dyld_slide_amount,
8836 			    vm_map_page_mask(current_map())),
8837 			    VM_PROT_READ | VM_PROT_EXECUTE,
8838 			    FALSE, VM_KERN_MEMORY_NONE,
8839 			    THREAD_UNINT, NULL, 0);
8840 			if (kr != KERN_SUCCESS) {
8841 //				printf("%s:%d map %p va 0x%llx -> 0x%x\n", __FUNCTION__, __LINE__, current_map(), vm_map_trunc_page(notification_address + dyld_slide_amount, vm_map_page_mask(current_map())), kr);
8842 			}
8843 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8844 				DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
8845 			}
8846 			kr = vm_fault(current_map(),
8847 			    vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
8848 			    vm_map_page_mask(current_map())),
8849 			    VM_PROT_READ | VM_PROT_EXECUTE,
8850 			    FALSE, VM_KERN_MEMORY_NONE,
8851 			    THREAD_UNINT, NULL, 0);
8852 			if (kr != KERN_SUCCESS) {
8853 //				printf("%s:%d map %p va 0x%llx -> 0x%x\n", __FUNCTION__, __LINE__, current_map(), vm_map_trunc_page(dyld_image_address + dyld_slide_amount, vm_map_page_mask(current_map())), kr);
8854 			}
8855 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8856 				DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
8857 			}
8858 			kr = vm_fault(current_map(),
8859 			    vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
8860 			    vm_map_page_mask(current_map())),
8861 			    VM_PROT_READ,
8862 			    FALSE, VM_KERN_MEMORY_NONE,
8863 			    THREAD_UNINT, NULL, 0);
8864 			if (kr != KERN_SUCCESS) {
8865 //				printf("%s:%d map %p va 0x%llx -> 0x%x\n", __FUNCTION__, __LINE__, current_map(), vm_map_trunc_page(dyld_version_address + dyld_slide_amount, vm_map_page_mask(current_map())), kr);
8866 			}
8867 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8868 				DEBUG4K_LOAD("dyld_all_image_infos_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
8869 			}
8870 			kr = vm_fault(current_map(),
8871 			    vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
8872 			    vm_map_page_mask(current_map())),
8873 			    VM_PROT_READ | VM_PROT_WRITE,
8874 			    FALSE, VM_KERN_MEMORY_NONE,
8875 			    THREAD_UNINT, NULL, 0);
8876 			if (kr != KERN_SUCCESS) {
8877 //				printf("%s:%d map %p va 0x%llx -> 0x%x\n", __FUNCTION__, __LINE__, current_map(), vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount, vm_map_page_mask(current_map())), kr);
8878 			}
8879 		}
8880 	}
8881 #endif /* FIXED_76621401 */
8882 }
8883 
8884 static int
8885 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
8886 {
8887 #pragma unused(oidp, arg2, req)
8888 	int changed;
8889 	errno_t error;
8890 	uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
8891 
8892 	error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
8893 	if (error) {
8894 		return error;
8895 	}
8896 
8897 	if (changed) {
8898 		os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
8899 	}
8900 
8901 	return 0;
8902 }
8903 
8904 EXPERIMENT_FACTOR_LEGACY_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
8905 
8906 SYSCTL_NODE(_kern, OID_AUTO, sec_transition,
8907     CTLFLAG_RD | CTLFLAG_LOCKED, 0, "sec_transition");
8908 
8909 #if DEBUG || DEVELOPMENT
8910 static int
sysctl_setup_ensure_pidversion_changes_on_exec(__unused int64_t in,int64_t * out)8911 sysctl_setup_ensure_pidversion_changes_on_exec(__unused int64_t in, int64_t *out)
8912 {
8913 	// Tweak nextpidversion to try to trigger a reuse (unless the exec code is doing the right thing)
8914 	int current_pid_version = proc_get_ro(current_proc())->p_idversion;
8915 	nextpidversion = current_pid_version;
8916 	*out = 0;
8917 	return KERN_SUCCESS;
8918 }
8919 
8920 SYSCTL_TEST_REGISTER(setup_ensure_pidversion_changes_on_exec, sysctl_setup_ensure_pidversion_changes_on_exec);
8921 #endif /* DEBUG || DEVELOPMENT */
8922