xref: /xnu-11417.121.6/bsd/kern/kern_exec.c (revision a1e26a70f38d1d7daa7b49b258e2f8538ad81650)
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/sysproto.h>
106 #include <sys/sysctl.h>
107 #include <sys/persona.h>
108 #include <sys/reason.h>
109 #if SYSV_SHM
110 #include <sys/shm_internal.h>           /* shmexec() */
111 #endif
112 #include <sys/ubc_internal.h>           /* ubc_map() */
113 #include <sys/spawn.h>
114 #include <sys/spawn_internal.h>
115 #include <sys/process_policy.h>
116 #include <sys/codesign.h>
117 #include <sys/random.h>
118 #include <crypto/sha1.h>
119 
120 #include <libkern/libkern.h>
121 #include <libkern/amfi/amfi.h>
122 #include <libkern/crypto/sha2.h>
123 #include <security/audit/audit.h>
124 
125 #include <ipc/ipc_types.h>
126 
127 #include <mach/mach_param.h>
128 #include <mach/mach_types.h>
129 #include <mach/port.h>
130 #include <mach/task.h>
131 #include <mach/task_access.h>
132 #include <mach/thread_act.h>
133 #include <mach/vm_map.h>
134 #include <mach/mach_vm.h>
135 #include <mach/vm_param.h>
136 #include <mach_debug/mach_debug_types.h>
137 
138 #include <kern/sched_prim.h> /* thread_wakeup() */
139 #include <kern/affinity.h>
140 #include <kern/assert.h>
141 #include <kern/ipc_kobject.h>
142 #include <kern/task.h>
143 #include <kern/thread.h>
144 #include <kern/coalition.h>
145 #include <kern/policy_internal.h>
146 #include <kern/kalloc.h>
147 #include <kern/zalloc.h> /* zone_userspace_reboot_checks() */
148 
149 #include <os/log.h>
150 
151 #if CONFIG_MACF
152 #include <security/mac_framework.h>
153 #include <security/mac_mach_internal.h>
154 #endif
155 
156 #if CONFIG_AUDIT
157 #include <bsm/audit_kevents.h>
158 #endif
159 
160 #if CONFIG_ARCADE
161 #include <kern/arcade.h>
162 #endif
163 
164 #include <vm/vm_map_xnu.h>
165 #include <vm/vm_kern_xnu.h>
166 #include <vm/vm_protos.h>
167 #include <vm/vm_fault.h>
168 #include <vm/vm_pageout_xnu.h>
169 #include <vm/pmap.h>
170 #include <vm/vm_reclaim_xnu.h>
171 
172 #include <kdp/kdp_dyld.h>
173 
174 #include <machine/machine_routines.h>
175 #include <machine/pal_routines.h>
176 
177 #include <pexpert/pexpert.h>
178 
179 #if CONFIG_MEMORYSTATUS
180 #include <sys/kern_memorystatus.h>
181 #endif
182 
183 #include <IOKit/IOBSD.h>
184 
185 #include "kern_exec_internal.h"
186 
187 #include <CodeSignature/Entitlements.h>
188 
189 #include <mach/exclaves.h>
190 
191 
192 extern boolean_t vm_darkwake_mode;
193 
194 /* enable crash reports on various exec failures */
195 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
196 
197 #if XNU_TARGET_OS_OSX
198 #if __has_feature(ptrauth_calls)
199 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
200 #endif /* __has_feature(ptrauth_calls) */
201 
202 #if DEBUG || DEVELOPMENT
203 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
204 #endif /* DEBUG || DEVELOPMENT */
205 #endif /* XNU_TARGET_OS_OSX */
206 
207 #if DEVELOPMENT || DEBUG
208 os_log_t exec_log_handle = NULL;
209 #define EXEC_LOG(fmt, ...)      \
210 do {    \
211 	if (exec_log_handle) {      \
212 	        os_log_with_type(exec_log_handle, OS_LOG_TYPE_INFO, "exec - %s:%d " fmt, __FUNCTION__, __LINE__, ##__VA_ARGS__);    \
213 	}   \
214 } while (0)
215 #else /* DEVELOPMENT || DEBUG */
216 #define EXEC_LOG(fmt, ...)  do { } while (0)
217 #endif /* DEVELOPMENT || DEBUG */
218 
219 #if CONFIG_DTRACE
220 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
221 extern void dtrace_proc_exec(proc_t);
222 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
223 
224 /*
225  * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
226  * we will store its value before actually calling it.
227  */
228 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
229 
230 #include <sys/dtrace_ptss.h>
231 #endif
232 
233 #if __has_feature(ptrauth_calls)
234 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
235     "vm_shared_region_per_team_id", 1);
236 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
237     "vm_shared_region_by_entitlement", 1);
238 
239 /* Upon userland request, reslide the shared cache. */
240 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
241     "vm_shared_region_reslide_aslr",
242 #if CONFIG_RESLIDE_SHARED_CACHE
243     1
244 #else
245     0
246 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
247     );
248 
249 /*
250  * Flag to control what processes should get shared cache randomize resliding
251  * after a fault in the shared cache region:
252  *
253  * 0 - all processes get a new randomized slide
254  * 1 - only platform processes get a new randomized slide
255  */
256 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
257     "vm_shared_region_reslide_restrict", 1);
258 
259 #if DEVELOPMENT || DEBUG
260 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
261     CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
262 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
263     CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
264 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
265     CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
266 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
267     CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
268 #endif
269 #endif /* __has_feature(ptrauth_calls) */
270 
271 #if DEVELOPMENT || DEBUG
272 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", true);
273 #else
274 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", false);
275 #endif
276 extern kern_return_t kern_register_userspace_coredump(task_t task, const char * name);
277 #define USERSPACE_COREDUMP_PANIC_ENTITLEMENT "com.apple.private.enable-coredump-on-panic"
278 #define USERSPACE_COREDUMP_PANIC_SEED_ENTITLEMENT \
279 	"com.apple.private.enable-coredump-on-panic-seed-privacy-approved"
280 
281 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
282 extern void task_set_did_exec_flag(task_t task);
283 extern void task_clear_exec_copy_flag(task_t task);
284 proc_t proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task,
285     task_t new_task, struct image_params *imgp, void **inherit);
286 boolean_t task_is_active(task_t);
287 boolean_t thread_is_active(thread_t thread);
288 void thread_copy_resource_info(thread_t dst_thread, thread_t src_thread);
289 void *ipc_importance_exec_switch_task(task_t old_task, task_t new_task);
290 extern void ipc_importance_release(void *elem);
291 extern boolean_t task_has_watchports(task_t task);
292 extern void task_set_no_smt(task_t task);
293 #if defined(HAS_APPLE_PAC)
294 char *task_get_vm_shared_region_id_and_jop_pid(task_t task, uint64_t *jop_pid);
295 #endif
296 task_t convert_port_to_task(ipc_port_t port);
297 
298 #if CONFIG_EXCLAVES
299 int task_add_conclave(task_t task, void *vnode, int64_t off, const char *task_conclave_id);
300 kern_return_t task_inherit_conclave(task_t old_task, task_t new_task, void *vnode, int64_t off);
301 #endif /* CONFIG_EXCLAVES */
302 
303 /*
304  * Mach things for which prototypes are unavailable from Mach headers
305  */
306 extern void ipc_task_enable(task_t task);
307 extern void ipc_task_reset(task_t task);
308 extern void ipc_thread_reset(thread_t thread);
309 
310 #if DEVELOPMENT || DEBUG
311 void task_importance_update_owner_info(task_t);
312 #endif
313 
314 extern struct savearea *get_user_regs(thread_t);
315 
316 __attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
317 
318 #include <kern/thread.h>
319 #include <kern/task.h>
320 #include <kern/ast.h>
321 #include <kern/mach_loader.h>
322 #include <kern/mach_fat.h>
323 #include <mach-o/fat.h>
324 #include <mach-o/loader.h>
325 #include <machine/vmparam.h>
326 #include <sys/imgact.h>
327 
328 #include <sys/sdt.h>
329 
330 
331 /*
332  * EAI_ITERLIMIT	The maximum number of times to iterate an image
333  *			activator in exec_activate_image() before treating
334  *			it as malformed/corrupt.
335  */
336 #define EAI_ITERLIMIT           3
337 
338 /*
339  * For #! interpreter parsing
340  */
341 #define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
342 #define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
343 
344 extern vm_map_t bsd_pageable_map;
345 extern const struct fileops vnops;
346 extern int nextpidversion;
347 
348 
349 #define USER_ADDR_ALIGN(addr, val) \
350 	( ( (user_addr_t)(addr) + (val) - 1) \
351 	        & ~((val) - 1) )
352 
353 /*
354  * For subsystem root support
355  */
356 #define SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT "com.apple.private.spawn-subsystem-root"
357 
358 /*
359  * Allow setting p_crash_behavior to trigger panic on crash
360  */
361 #define SPAWN_SET_PANIC_CRASH_BEHAVIOR "com.apple.private.spawn-panic-crash-behavior"
362 
363 /* Platform Code Exec Logging */
364 static int platform_exec_logging = 0;
365 
366 SYSCTL_DECL(_security_mac);
367 
368 SYSCTL_INT(_security_mac, OID_AUTO, platform_exec_logging, CTLFLAG_RW, &platform_exec_logging, 0,
369     "log cdhashes for all platform binary executions");
370 
371 static os_log_t peLog = OS_LOG_DEFAULT;
372 
373 struct exception_port_action_t {
374 	ipc_port_t port;
375 	_ps_port_action_t *port_action;
376 };
377 
378 struct exec_port_actions {
379 	uint32_t exception_port_count;
380 	uint32_t portwatch_count;
381 	uint32_t registered_count;
382 	struct exception_port_action_t *excport_array;
383 	ipc_port_t *portwatch_array;
384 	ipc_port_t registered_array[TASK_PORT_REGISTER_MAX];
385 };
386 
387 struct image_params;    /* Forward */
388 static int exec_activate_image(struct image_params *imgp);
389 static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
390 static int load_return_to_errno(load_return_t lrtn);
391 static int execargs_alloc(struct image_params *imgp);
392 static int execargs_free(struct image_params *imgp);
393 static int exec_check_permissions(struct image_params *imgp);
394 static int exec_extract_strings(struct image_params *imgp);
395 static int exec_add_apple_strings(struct image_params *imgp, const load_result_t *load_result, task_t task);
396 static int exec_handle_sugid(struct image_params *imgp);
397 static int sugid_scripts = 0;
398 SYSCTL_INT(_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
399 static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
400 static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
401 static void exec_resettextvp(proc_t, struct image_params *);
402 static int process_signature(proc_t, struct image_params *);
403 static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
404 static errno_t exec_handle_port_actions(struct image_params *imgp,
405     struct exec_port_actions *port_actions);
406 static errno_t exec_handle_exception_port_actions(const struct image_params *imgp,
407     const struct exec_port_actions *port_actions);
408 static errno_t exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
409     task_role_t psa_darwin_role, struct exec_port_actions *port_actions);
410 static void exec_port_actions_destroy(struct exec_port_actions *port_actions);
411 
412 /*
413  * exec_add_user_string
414  *
415  * Add the requested string to the string space area.
416  *
417  * Parameters;	struct image_params *		image parameter block
418  *		user_addr_t			string to add to strings area
419  *		int				segment from which string comes
420  *		boolean_t			TRUE if string contributes to NCARGS
421  *
422  * Returns:	0			Success
423  *		!0			Failure errno from copyinstr()
424  *
425  * Implicit returns:
426  *		(imgp->ip_strendp)	updated location of next add, if any
427  *		(imgp->ip_strspace)	updated byte count of space remaining
428  *		(imgp->ip_argspace) updated byte count of space in NCARGS
429  */
430 __attribute__((noinline))
431 static int
exec_add_user_string(struct image_params * imgp,user_addr_t str,int seg,boolean_t is_ncargs)432 exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
433 {
434 	int error = 0;
435 
436 	do {
437 		size_t len = 0;
438 		int space;
439 
440 		if (is_ncargs) {
441 			space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
442 		} else {
443 			space = imgp->ip_strspace;
444 		}
445 
446 		if (space <= 0) {
447 			error = E2BIG;
448 			break;
449 		}
450 
451 		if (!UIO_SEG_IS_USER_SPACE(seg)) {
452 			char *kstr = CAST_DOWN(char *, str);     /* SAFE */
453 			error = copystr(kstr, imgp->ip_strendp, space, &len);
454 		} else {
455 			error = copyinstr(str, imgp->ip_strendp, space, &len);
456 		}
457 
458 		imgp->ip_strendp += len;
459 		imgp->ip_strspace -= len;
460 		if (is_ncargs) {
461 			imgp->ip_argspace -= len;
462 		}
463 	} while (error == ENAMETOOLONG);
464 
465 	return error;
466 }
467 
468 /*
469  * dyld is now passed the executable path as a getenv-like variable
470  * in the same fashion as the stack_guard and malloc_entropy keys.
471  */
472 #define EXECUTABLE_KEY "executable_path="
473 
474 /*
475  * exec_save_path
476  *
477  * To support new app package launching for Mac OS X, the dyld needs the
478  * first argument to execve() stored on the user stack.
479  *
480  * Save the executable path name at the bottom of the strings area and set
481  * the argument vector pointer to the location following that to indicate
482  * the start of the argument and environment tuples, setting the remaining
483  * string space count to the size of the string area minus the path length.
484  *
485  * Parameters;	struct image_params *		image parameter block
486  *		char *				path used to invoke program
487  *		int				segment from which path comes
488  *
489  * Returns:	int			0	Success
490  *		EFAULT				Bad address
491  *	copy[in]str:EFAULT			Bad address
492  *	copy[in]str:ENAMETOOLONG		Filename too long
493  *
494  * Implicit returns:
495  *		(imgp->ip_strings)		saved path
496  *		(imgp->ip_strspace)		space remaining in ip_strings
497  *		(imgp->ip_strendp)		start of remaining copy area
498  *		(imgp->ip_argspace)		space remaining of NCARGS
499  *		(imgp->ip_applec)		Initial applev[0]
500  *
501  * Note:	We have to do this before the initial namei() since in the
502  *		path contains symbolic links, namei() will overwrite the
503  *		original path buffer contents.  If the last symbolic link
504  *		resolved was a relative pathname, we would lose the original
505  *		"path", which could be an absolute pathname. This might be
506  *		unacceptable for dyld.
507  */
508 static int
exec_save_path(struct image_params * imgp,user_addr_t path,int seg,const char ** excpath)509 exec_save_path(struct image_params *imgp, user_addr_t path, int seg, const char **excpath)
510 {
511 	int error;
512 	size_t len;
513 	char *kpath;
514 
515 	// imgp->ip_strings can come out of a cache, so we need to obliterate the
516 	// old path.
517 	memset(imgp->ip_strings, '\0', strlen(EXECUTABLE_KEY) + MAXPATHLEN);
518 
519 	len = MIN(MAXPATHLEN, imgp->ip_strspace);
520 
521 	switch (seg) {
522 	case UIO_USERSPACE32:
523 	case UIO_USERSPACE64:   /* Same for copyin()... */
524 		error = copyinstr(path, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
525 		break;
526 	case UIO_SYSSPACE:
527 		kpath = CAST_DOWN(char *, path); /* SAFE */
528 		error = copystr(kpath, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
529 		break;
530 	default:
531 		error = EFAULT;
532 		break;
533 	}
534 
535 	if (!error) {
536 		bcopy(EXECUTABLE_KEY, imgp->ip_strings, strlen(EXECUTABLE_KEY));
537 		len += strlen(EXECUTABLE_KEY);
538 
539 		imgp->ip_strendp += len;
540 		imgp->ip_strspace -= len;
541 
542 		if (excpath) {
543 			*excpath = imgp->ip_strings + strlen(EXECUTABLE_KEY);
544 		}
545 	}
546 
547 	return error;
548 }
549 
550 /*
551  * exec_reset_save_path
552  *
553  * If we detect a shell script, we need to reset the string area
554  * state so that the interpreter can be saved onto the stack.
555  *
556  * Parameters;	struct image_params *		image parameter block
557  *
558  * Returns:	int			0	Success
559  *
560  * Implicit returns:
561  *		(imgp->ip_strings)		saved path
562  *		(imgp->ip_strspace)		space remaining in ip_strings
563  *		(imgp->ip_strendp)		start of remaining copy area
564  *		(imgp->ip_argspace)		space remaining of NCARGS
565  *
566  */
567 static int
exec_reset_save_path(struct image_params * imgp)568 exec_reset_save_path(struct image_params *imgp)
569 {
570 	imgp->ip_strendp = imgp->ip_strings;
571 	imgp->ip_argspace = NCARGS;
572 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
573 
574 	return 0;
575 }
576 
577 /*
578  * exec_shell_imgact
579  *
580  * Image activator for interpreter scripts.  If the image begins with
581  * the characters "#!", then it is an interpreter script.  Verify the
582  * length of the script line indicating the interpreter is not in
583  * excess of the maximum allowed size.  If this is the case, then
584  * break out the arguments, if any, which are separated by white
585  * space, and copy them into the argument save area as if they were
586  * provided on the command line before all other arguments.  The line
587  * ends when we encounter a comment character ('#') or newline.
588  *
589  * Parameters;	struct image_params *	image parameter block
590  *
591  * Returns:	-1			not an interpreter (keep looking)
592  *		-3			Success: interpreter: relookup
593  *		>0			Failure: interpreter: error number
594  *
595  * A return value other than -1 indicates subsequent image activators should
596  * not be given the opportunity to attempt to activate the image.
597  */
598 static int
exec_shell_imgact(struct image_params * imgp)599 exec_shell_imgact(struct image_params *imgp)
600 {
601 	char *vdata = imgp->ip_vdata;
602 	char *ihp;
603 	char *line_startp, *line_endp;
604 	char *interp;
605 
606 	/*
607 	 * Make sure it's a shell script.  If we've already redirected
608 	 * from an interpreted file once, don't do it again.
609 	 */
610 	if (vdata[0] != '#' ||
611 	    vdata[1] != '!' ||
612 	    (imgp->ip_flags & IMGPF_INTERPRET) != 0) {
613 		return -1;
614 	}
615 
616 	if (imgp->ip_origcputype != 0) {
617 		/* Fat header previously matched, don't allow shell script inside */
618 		return -1;
619 	}
620 
621 	imgp->ip_flags |= IMGPF_INTERPRET;
622 	imgp->ip_interp_sugid_fd = -1;
623 	imgp->ip_interp_buffer[0] = '\0';
624 
625 	/* Check to see if SUGID scripts are permitted.  If they aren't then
626 	 * clear the SUGID bits.
627 	 * imgp->ip_vattr is known to be valid.
628 	 */
629 	if (sugid_scripts == 0) {
630 		imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
631 	}
632 
633 	/* Try to find the first non-whitespace character */
634 	for (ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++) {
635 		if (IS_EOL(*ihp)) {
636 			/* Did not find interpreter, "#!\n" */
637 			return ENOEXEC;
638 		} else if (IS_WHITESPACE(*ihp)) {
639 			/* Whitespace, like "#!    /bin/sh\n", keep going. */
640 		} else {
641 			/* Found start of interpreter */
642 			break;
643 		}
644 	}
645 
646 	if (ihp == &vdata[IMG_SHSIZE]) {
647 		/* All whitespace, like "#!           " */
648 		return ENOEXEC;
649 	}
650 
651 	line_startp = ihp;
652 
653 	/* Try to find the end of the interpreter+args string */
654 	for (; ihp < &vdata[IMG_SHSIZE]; ihp++) {
655 		if (IS_EOL(*ihp)) {
656 			/* Got it */
657 			break;
658 		} else {
659 			/* Still part of interpreter or args */
660 		}
661 	}
662 
663 	if (ihp == &vdata[IMG_SHSIZE]) {
664 		/* A long line, like "#! blah blah blah" without end */
665 		return ENOEXEC;
666 	}
667 
668 	/* Backtrack until we find the last non-whitespace */
669 	while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
670 		ihp--;
671 	}
672 
673 	/* The character after the last non-whitespace is our logical end of line */
674 	line_endp = ihp + 1;
675 
676 	/*
677 	 * Now we have pointers to the usable part of:
678 	 *
679 	 * "#!  /usr/bin/int first    second   third    \n"
680 	 *      ^ line_startp                       ^ line_endp
681 	 */
682 
683 	/* copy the interpreter name */
684 	interp = imgp->ip_interp_buffer;
685 	for (ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++) {
686 		*interp++ = *ihp;
687 	}
688 	*interp = '\0';
689 
690 	exec_reset_save_path(imgp);
691 	exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
692 	    UIO_SYSSPACE, NULL);
693 
694 	/* Copy the entire interpreter + args for later processing into argv[] */
695 	interp = imgp->ip_interp_buffer;
696 	for (ihp = line_startp; (ihp < line_endp); ihp++) {
697 		*interp++ = *ihp;
698 	}
699 	*interp = '\0';
700 
701 #if CONFIG_SETUID
702 	/*
703 	 * If we have an SUID or SGID script, create a file descriptor
704 	 * from the vnode and pass /dev/fd/%d instead of the actual
705 	 * path name so that the script does not get opened twice
706 	 */
707 	if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
708 		proc_t p;
709 		struct fileproc *fp;
710 		int fd;
711 		int error;
712 
713 		p = vfs_context_proc(imgp->ip_vfs_context);
714 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &fd);
715 		if (error) {
716 			return error;
717 		}
718 
719 		fp->fp_glob->fg_flag = FREAD;
720 		fp->fp_glob->fg_ops = &vnops;
721 		fp_set_data(fp, imgp->ip_vp);
722 
723 		proc_fdlock(p);
724 		procfdtbl_releasefd(p, fd, NULL);
725 		fp_drop(p, fd, fp, 1);
726 		proc_fdunlock(p);
727 		vnode_ref(imgp->ip_vp);
728 
729 		imgp->ip_interp_sugid_fd = fd;
730 	}
731 #endif /* CONFIG_SETUID */
732 
733 	return -3;
734 }
735 
736 
737 
738 /*
739  * exec_fat_imgact
740  *
741  * Image activator for fat 1.0 binaries.  If the binary is fat, then we
742  * need to select an image from it internally, and make that the image
743  * we are going to attempt to execute.  At present, this consists of
744  * reloading the first page for the image with a first page from the
745  * offset location indicated by the fat header.
746  *
747  * Parameters;	struct image_params *	image parameter block
748  *
749  * Returns:	-1			not a fat binary (keep looking)
750  *		-2			Success: encapsulated binary: reread
751  *		>0			Failure: error number
752  *
753  * Important:	This image activator is byte order neutral.
754  *
755  * Note:	A return value other than -1 indicates subsequent image
756  *		activators should not be given the opportunity to attempt
757  *		to activate the image.
758  *
759  *              If we find an encapsulated binary, we make no assertions
760  *		about its  validity; instead, we leave that up to a rescan
761  *		for an activator to claim it, and, if it is claimed by one,
762  *		that activator is responsible for determining validity.
763  */
764 static int
exec_fat_imgact(struct image_params * imgp)765 exec_fat_imgact(struct image_params *imgp)
766 {
767 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
768 	kauth_cred_t cred = kauth_cred_proc_ref(p);
769 	struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
770 	struct _posix_spawnattr *psa = NULL;
771 	struct fat_arch fat_arch;
772 	int resid, error;
773 	load_return_t lret;
774 
775 	if (imgp->ip_origcputype != 0) {
776 		/* Fat header previously matched, don't allow another fat file inside */
777 		error = -1; /* not claimed */
778 		goto bad;
779 	}
780 
781 	/* Make sure it's a fat binary */
782 	if (OSSwapBigToHostInt32(fat_header->magic) != FAT_MAGIC) {
783 		error = -1; /* not claimed */
784 		goto bad;
785 	}
786 
787 	/* imgp->ip_vdata has PAGE_SIZE, zerofilled if the file is smaller */
788 	lret = fatfile_validate_fatarches((vm_offset_t)fat_header, PAGE_SIZE,
789 	    (off_t)imgp->ip_vattr->va_data_size);
790 	if (lret != LOAD_SUCCESS) {
791 		error = load_return_to_errno(lret);
792 		goto bad;
793 	}
794 
795 	/* If posix_spawn binprefs exist, respect those prefs. */
796 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
797 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
798 		uint32_t pr = 0;
799 
800 		/* Check each preference listed against all arches in header */
801 		for (pr = 0; pr < NBINPREFS; pr++) {
802 			cpu_type_t pref = psa->psa_binprefs[pr];
803 			cpu_type_t subpref = psa->psa_subcpuprefs[pr];
804 
805 			if (pref == 0) {
806 				/* No suitable arch in the pref list */
807 				error = EBADARCH;
808 				goto bad;
809 			}
810 
811 			if (pref == CPU_TYPE_ANY) {
812 				/* Fall through to regular grading */
813 				goto regular_grading;
814 			}
815 
816 			lret = fatfile_getbestarch_for_cputype(pref,
817 			    subpref,
818 			    (vm_offset_t)fat_header,
819 			    PAGE_SIZE,
820 			    imgp,
821 			    &fat_arch);
822 			if (lret == LOAD_SUCCESS) {
823 				goto use_arch;
824 			}
825 		}
826 
827 		/* Requested binary preference was not honored */
828 		error = EBADEXEC;
829 		goto bad;
830 	}
831 
832 regular_grading:
833 	/* Look up our preferred architecture in the fat file. */
834 	lret = fatfile_getbestarch((vm_offset_t)fat_header,
835 	    PAGE_SIZE,
836 	    imgp,
837 	    &fat_arch,
838 	    (p->p_flag & P_AFFINITY) != 0);
839 	if (lret != LOAD_SUCCESS) {
840 		error = load_return_to_errno(lret);
841 		goto bad;
842 	}
843 
844 use_arch:
845 	/* Read the Mach-O header out of fat_arch */
846 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
847 	    PAGE_SIZE, fat_arch.offset,
848 	    UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
849 	    cred, &resid, p);
850 	if (error) {
851 		if (error == ERESTART) {
852 			error = EINTR;
853 		}
854 		goto bad;
855 	}
856 
857 	if (resid) {
858 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
859 	}
860 
861 	/* Success.  Indicate we have identified an encapsulated binary */
862 	error = -2;
863 	imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
864 	imgp->ip_arch_size = (user_size_t)fat_arch.size;
865 	imgp->ip_origcputype = fat_arch.cputype;
866 	imgp->ip_origcpusubtype = fat_arch.cpusubtype;
867 
868 bad:
869 	kauth_cred_unref(&cred);
870 	return error;
871 }
872 
873 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)874 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
875 {
876 	int ret;
877 
878 	(void)task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0, false);
879 	task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
880 	if (result->is_64bit_addr) {
881 		OSBitOrAtomic(P_LP64, &p->p_flag);
882 		get_bsdthread_info(thread)->uu_flag |= UT_LP64;
883 	} else {
884 		OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
885 		get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
886 	}
887 	task_set_mach_header_address(task, result->mach_header);
888 
889 	ret = thread_state_initialize(thread);
890 	if (ret != KERN_SUCCESS) {
891 		return ret;
892 	}
893 
894 	if (result->threadstate) {
895 		uint32_t *ts = result->threadstate;
896 		uint32_t total_size = (uint32_t)result->threadstate_sz;
897 
898 		while (total_size > 0) {
899 			uint32_t flavor = *ts++;
900 			uint32_t size = *ts++;
901 
902 			ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
903 			if (ret) {
904 				return ret;
905 			}
906 			ts += size;
907 			total_size -= (size + 2) * sizeof(uint32_t);
908 		}
909 	}
910 
911 	thread_setentrypoint(thread, result->entry_point);
912 
913 	return KERN_SUCCESS;
914 }
915 
916 #if (DEVELOPMENT || DEBUG)
917 extern char panic_on_proc_crash[];
918 extern int use_panic_on_proc_crash;
919 
920 extern char panic_on_proc_exit[];
921 extern int use_panic_on_proc_exit;
922 
923 extern char panic_on_proc_spawn_fail[];
924 extern int use_panic_on_proc_spawn_fail;
925 
926 static inline void
set_crash_behavior_from_bootarg(proc_t p)927 set_crash_behavior_from_bootarg(proc_t p)
928 {
929 	if (use_panic_on_proc_crash && strcmp(p->p_comm, panic_on_proc_crash) == 0) {
930 		printf("will panic on proc crash: %s\n", p->p_comm);
931 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_CRASH;
932 	}
933 
934 	if (use_panic_on_proc_exit && strcmp(p->p_comm, panic_on_proc_exit) == 0) {
935 		printf("will panic on proc exit: %s\n", p->p_comm);
936 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_EXIT;
937 	}
938 
939 	if (use_panic_on_proc_spawn_fail && strcmp(p->p_comm, panic_on_proc_spawn_fail) == 0) {
940 		printf("will panic on proc spawn fail: %s\n", p->p_comm);
941 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_SPAWN_FAIL;
942 	}
943 }
944 #endif
945 
946 void
set_proc_name(struct image_params * imgp,proc_t p)947 set_proc_name(struct image_params *imgp, proc_t p)
948 {
949 	uint64_t buflen = imgp->ip_ndp->ni_cnd.cn_namelen;
950 	const int p_name_len = sizeof(p->p_name) - 1;
951 	const int p_comm_len = sizeof(p->p_comm) - 1;
952 
953 	if (buflen > p_name_len) {
954 		buflen = p_name_len;
955 	}
956 
957 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name, buflen);
958 	p->p_name[buflen] = '\0';
959 
960 	if (buflen > p_comm_len) {
961 		static_assert(MAXCOMLEN + 1 == sizeof(p->p_comm));
962 		buflen = p_comm_len;
963 	}
964 
965 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm, buflen);
966 	p->p_comm[buflen] = '\0';
967 
968 #if (DEVELOPMENT || DEBUG)
969 	/*
970 	 * This happens during image activation, so the crash behavior flags from
971 	 * posix_spawn will have already been set. So we don't have to worry about
972 	 * this being overridden.
973 	 */
974 	set_crash_behavior_from_bootarg(p);
975 #endif
976 }
977 
978 #if __has_feature(ptrauth_calls)
979 /**
980  * Returns a team ID string that may be used to assign a shared region.
981  *
982  * Platform binaries do not have team IDs and will return NULL.  Non-platform
983  * binaries without a team ID will be assigned an artificial team ID of ""
984  * (empty string) so that they will not be assigned to the default shared
985  * region.
986  *
987  * @param imgp image parameter block
988  * @return NULL if this is a platform binary, or an appropriate team ID string
989  *         otherwise
990  */
991 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)992 get_teamid_for_shared_region(struct image_params *imgp)
993 {
994 	assert(imgp->ip_vp != NULL);
995 
996 	const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
997 	if (ret) {
998 		return ret;
999 	}
1000 
1001 	struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
1002 	if (csblob_get_platform_binary(blob)) {
1003 		return NULL;
1004 	} else {
1005 		static const char *NO_TEAM_ID = "";
1006 		return NO_TEAM_ID;
1007 	}
1008 }
1009 
1010 /**
1011  * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
1012  *
1013  * @param cpusubtype Mach-O style CPU subtype
1014  * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
1015  */
1016 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)1017 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
1018 {
1019 	return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1020 	       CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
1021 }
1022 
1023 #endif /* __has_feature(ptrauth_calls) */
1024 
1025 /**
1026  * Returns whether a type/subtype slice matches the requested
1027  * type/subtype.
1028  *
1029  * @param mask Bits to mask from the requested/tested cpu type
1030  * @param req_cpu Requested cpu type
1031  * @param req_subcpu Requested cpu subtype
1032  * @param test_cpu Tested slice cpu type
1033  * @param test_subcpu Tested slice cpu subtype
1034  */
1035 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)1036 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
1037     cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
1038     cpu_subtype_t test_subcpu)
1039 {
1040 	if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
1041 		return FALSE;
1042 	}
1043 
1044 	test_subcpu &= ~CPU_SUBTYPE_MASK;
1045 	req_subcpu  &= ~CPU_SUBTYPE_MASK;
1046 
1047 	if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
1048 		return FALSE;
1049 	}
1050 
1051 	return TRUE;
1052 }
1053 
1054 
1055 // Check entitlements to see if this is a hardened runtime binary.
1056 // Save this in load_result until later for two purposes:
1057 // 1. Once the task is created, we can mark it as hardened runtime if needed
1058 // 2. we can propagate which entitlements are present to the apple array
1059 static inline void
encode_HR_entitlement(const char * entitlement,HR_flags_t mask,const struct image_params * imgp,load_result_t * load_result)1060 encode_HR_entitlement(const char *entitlement, HR_flags_t mask,
1061     const struct image_params *imgp, load_result_t *load_result)
1062 {
1063 	if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
1064 		load_result->hardened_runtime_binary |= mask;
1065 	}
1066 }
1067 
1068 /*
1069  * If the passed in executable's vnode should use the RSR
1070  * shared region, then this should return TRUE, otherwise, return FALSE.
1071  */
1072 static uint32_t rsr_current_version = 0;
1073 boolean_t (*rsr_check_vnode)(void *vnode) = NULL;
1074 
1075 boolean_t
vnode_is_rsr(vnode_t vp)1076 vnode_is_rsr(vnode_t vp)
1077 {
1078 	if (!(vnode_isreg(vp) && vnode_tag(vp) == VT_APFS)) {
1079 		return FALSE;
1080 	}
1081 
1082 	if (rsr_check_vnode != NULL && rsr_check_vnode((void *)vp)) {
1083 		return TRUE;
1084 	}
1085 	return FALSE;
1086 }
1087 
1088 /* Runtime security mitigations */
1089 
1090 /*
1091  * Hardened-process.
1092  *
1093  * Security mitigations follow the notion of "hardened-process": binaries that we
1094  * have identified as being security critical. They are identified by the
1095  * com.apple.developer.hardened-process entitlement, which is required to further
1096  * configure the other security mitigations.
1097  */
1098 #define SPAWN_ENABLE_HARDENED_PROCESS "com.apple.developer.hardened-process"
1099 
1100 /*
1101  * Hardened-Heap.
1102  *
1103  * This mitigation extends libmalloc xzone with a number of security features,
1104  * most notably increasing the number of buckets and adding guard pages.
1105  * The presence of the entitlement opts the binary into the feature.
1106  */
1107 #define SPAWN_ENABLE_HARDENED_HEAP "com.apple.developer.hardened-process.hardened-heap"
1108 
1109 
1110 
1111 /*
1112  * Enablement of hardened-heap is pretty straightforward and solely depends on
1113  * the presence of the associated entitlement.
1114  */
1115 static inline void
exec_setup_hardened_heap(struct image_params * imgp,task_t task)1116 exec_setup_hardened_heap(struct image_params *imgp, task_t task)
1117 {
1118 	if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
1119 	    SPAWN_ENABLE_HARDENED_HEAP)) {
1120 		task_set_hardened_heap(task);
1121 	}
1122 }
1123 
1124 
1125 
1126 /*
1127  * This routine configures the various runtime mitigations we can apply to a process.
1128  * Returns true on success, false on failure. Failure will be fatal in exec_mach_imgact().
1129  */
1130 static inline errno_t
exec_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)1131 exec_setup_runtime_mitigations(struct image_params *imgp, __unused load_result_t *load_result,
1132     __unused task_t old_task, task_t new_task, __unused vm_map_t map, __unused proc_t proc)
1133 {
1134 	errno_t retval = 0;
1135 
1136 	/*
1137 	 * Hardened-heap enables a set of extra security features in our system memory allocator.
1138 	 */
1139 	exec_setup_hardened_heap(imgp, new_task);
1140 
1141 
1142 	return retval;
1143 }
1144 
1145 uint32_t
rsr_get_version(void)1146 rsr_get_version(void)
1147 {
1148 	return os_atomic_load(&rsr_current_version, relaxed);
1149 }
1150 
1151 void
rsr_bump_version(void)1152 rsr_bump_version(void)
1153 {
1154 	os_atomic_inc(&rsr_current_version, relaxed);
1155 }
1156 
1157 #if XNU_TARGET_OS_OSX
1158 static int
1159 rsr_version_sysctl SYSCTL_HANDLER_ARGS
1160 {
1161 #pragma unused(arg1, arg2, oidp)
1162 	int value = rsr_get_version();
1163 	int error = SYSCTL_OUT(req, &value, sizeof(int));
1164 	if (error) {
1165 		return error;
1166 	}
1167 
1168 	if (!req->newptr) {
1169 		return 0;
1170 	}
1171 
1172 	error = SYSCTL_IN(req, &value, sizeof(int));
1173 	if (error) {
1174 		return error;
1175 	}
1176 	if (value != 0) {
1177 		rsr_bump_version();
1178 	}
1179 	return 0;
1180 }
1181 
1182 
1183 SYSCTL_PROC(_vm, OID_AUTO, shared_region_control,
1184     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
1185     0, 0, rsr_version_sysctl, "I", "");
1186 #endif /* XNU_TARGET_OS_OSX */
1187 
1188 /*
1189  * exec_mach_imgact
1190  *
1191  * Image activator for mach-o 1.0 binaries.
1192  *
1193  * Parameters;	struct image_params *	image parameter block
1194  *
1195  * Returns:	-1			not a fat binary (keep looking)
1196  *		-2			Success: encapsulated binary: reread
1197  *		>0			Failure: error number
1198  *		EBADARCH		Mach-o binary, but with an unrecognized
1199  *					architecture
1200  *		ENOMEM			No memory for child process after -
1201  *					can only happen after vfork()
1202  *
1203  * Important:	This image activator is NOT byte order neutral.
1204  *
1205  * Note:	A return value other than -1 indicates subsequent image
1206  *		activators should not be given the opportunity to attempt
1207  *		to activate the image.
1208  */
1209 static int
exec_mach_imgact(struct image_params * imgp)1210 exec_mach_imgact(struct image_params *imgp)
1211 {
1212 	struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1213 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
1214 	int                     error = 0;
1215 	task_t                  task;
1216 	task_t                  new_task = NULL;    /* protected by vfexec */
1217 	thread_t                thread;
1218 	struct uthread          *uthread;
1219 	vm_map_switch_context_t switch_ctx;
1220 	vm_map_t old_map = VM_MAP_NULL;
1221 	vm_map_t map = VM_MAP_NULL;
1222 	load_return_t           lret;
1223 	load_result_t           load_result = {};
1224 	struct _posix_spawnattr *psa = NULL;
1225 	int                     spawn = (imgp->ip_flags & IMGPF_SPAWN);
1226 	const int               vfexec = 0;
1227 	int                     exec = (imgp->ip_flags & IMGPF_EXEC);
1228 	os_reason_t             exec_failure_reason = OS_REASON_NULL;
1229 	boolean_t               reslide = FALSE;
1230 	char *                  userspace_coredump_name = NULL;
1231 
1232 	/*
1233 	 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1234 	 * is a reserved field on the end, so for the most part, we can
1235 	 * treat them as if they were identical. Reverse-endian Mach-O
1236 	 * binaries are recognized but not compatible.
1237 	 */
1238 	if ((mach_header->magic == MH_CIGAM) ||
1239 	    (mach_header->magic == MH_CIGAM_64)) {
1240 		error = EBADARCH;
1241 		goto bad;
1242 	}
1243 
1244 	if ((mach_header->magic != MH_MAGIC) &&
1245 	    (mach_header->magic != MH_MAGIC_64)) {
1246 		error = -1;
1247 		goto bad;
1248 	}
1249 
1250 	if (mach_header->filetype != MH_EXECUTE) {
1251 		error = -1;
1252 		goto bad;
1253 	}
1254 
1255 	if (imgp->ip_origcputype != 0) {
1256 		/* Fat header previously had an idea about this thin file */
1257 		if (imgp->ip_origcputype != mach_header->cputype ||
1258 		    imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1259 			error = EBADARCH;
1260 			goto bad;
1261 		}
1262 	} else {
1263 		imgp->ip_origcputype = mach_header->cputype;
1264 		imgp->ip_origcpusubtype = mach_header->cpusubtype;
1265 	}
1266 
1267 	task = current_task();
1268 	thread = current_thread();
1269 	uthread = get_bsdthread_info(thread);
1270 
1271 	if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1272 		imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1273 	}
1274 
1275 
1276 	/* If posix_spawn binprefs exist, respect those prefs. */
1277 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1278 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
1279 		int pr = 0;
1280 		for (pr = 0; pr < NBINPREFS; pr++) {
1281 			cpu_type_t pref = psa->psa_binprefs[pr];
1282 			cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1283 
1284 			if (pref == 0) {
1285 				/* No suitable arch in the pref list */
1286 				error = EBADARCH;
1287 				goto bad;
1288 			}
1289 
1290 			if (pref == CPU_TYPE_ANY) {
1291 				/* Jump to regular grading */
1292 				goto grade;
1293 			}
1294 
1295 			if (binary_match(CPU_ARCH_MASK, pref, subpref,
1296 			    imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1297 				goto grade;
1298 			}
1299 		}
1300 		error = EBADARCH;
1301 		goto bad;
1302 	}
1303 grade:
1304 	if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1305 	    imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1306 		error = EBADARCH;
1307 		goto bad;
1308 	}
1309 
1310 	if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1311 	    imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1312 #if __x86_64__
1313 		const char *excpath;
1314 		error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1315 		os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1316 #endif
1317 		error = EBADARCH;
1318 		goto bad;
1319 	}
1320 
1321 #if defined(HAS_APPLE_PAC)
1322 	assert(mach_header->cputype == CPU_TYPE_ARM64
1323 	    );
1324 
1325 	if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1326 	    arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1327 	    ) {
1328 		imgp->ip_flags &= ~IMGPF_NOJOP;
1329 	} else {
1330 		imgp->ip_flags |= IMGPF_NOJOP;
1331 	}
1332 #endif
1333 
1334 	/* Copy in arguments/environment from the old process */
1335 	error = exec_extract_strings(imgp);
1336 	if (error) {
1337 		goto bad;
1338 	}
1339 
1340 	AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1341 	    imgp->ip_endargv - imgp->ip_startargv);
1342 	AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1343 	    imgp->ip_endenvv - imgp->ip_endargv);
1344 
1345 	/* reset local idea of thread, uthread, task */
1346 	thread = imgp->ip_new_thread;
1347 	uthread = get_bsdthread_info(thread);
1348 	task = new_task = get_threadtask(thread);
1349 
1350 	/*
1351 	 *	Load the Mach-O file.
1352 	 *
1353 	 * NOTE: An error after this point  indicates we have potentially
1354 	 * destroyed or overwritten some process state while attempting an
1355 	 * execve() following a vfork(), which is an unrecoverable condition.
1356 	 * We send the new process an immediate SIGKILL to avoid it executing
1357 	 * any instructions in the mutated address space. For true spawns,
1358 	 * this is not the case, and "too late" is still not too late to
1359 	 * return an error code to the parent process.
1360 	 */
1361 
1362 	/*
1363 	 * Actually load the image file we previously decided to load.
1364 	 */
1365 	lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1366 	if (lret != LOAD_SUCCESS) {
1367 		error = load_return_to_errno(lret);
1368 
1369 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1370 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1371 		if (lret == LOAD_BADMACHO_UPX) {
1372 			set_proc_name(imgp, p);
1373 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1374 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1375 		} else {
1376 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1377 
1378 			if (bootarg_execfailurereports) {
1379 				set_proc_name(imgp, p);
1380 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1381 			}
1382 		}
1383 
1384 		exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1385 
1386 		goto badtoolate;
1387 	}
1388 
1389 	assert(imgp->ip_free_map == NULL);
1390 
1391 
1392 	// It's safe to check entitlements anytime after `load_machfile` if you check
1393 	// based on the vnode in imgp. We must perform this entitlement check
1394 	// before we start using load_result->hardened_runtime_binary further down
1395 	load_result.hardened_runtime_binary = 0;
1396 	encode_HR_entitlement(kCSWebBrowserHostEntitlement, BrowserHostEntitlementMask, imgp, &load_result);
1397 	encode_HR_entitlement(kCSWebBrowserGPUEntitlement, BrowserGPUEntitlementMask, imgp, &load_result);
1398 	encode_HR_entitlement(kCSWebBrowserNetworkEntitlement, BrowserNetworkEntitlementMask, imgp, &load_result);
1399 	encode_HR_entitlement(kCSWebBrowserWebContentEntitlement, BrowserWebContentEntitlementMask, imgp, &load_result);
1400 
1401 	/*
1402 	 * ERROR RECOVERY
1403 	 *
1404 	 * load_machfile() returned the new VM map ("map") but we haven't
1405 	 * committed to it yet.
1406 	 * Any error path between here and the point where we commit to using
1407 	 * the new "map" (with swap_task_map()) should deallocate "map".
1408 	 */
1409 
1410 #ifndef KASAN
1411 	/*
1412 	 * Security: zone sanity checks on fresh boot or initproc re-exec.
1413 	 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1414 	 * which means here is the earliest point we can assert on empty service port label zone,
1415 	 * after load_machfile() above terminates old launchd's IPC space.
1416 	 *
1417 	 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1418 	 * under quarantine.
1419 	 */
1420 	if (task_pid(task) == 1) {
1421 		zone_userspace_reboot_checks();
1422 	}
1423 #endif
1424 
1425 	proc_lock(p);
1426 	p->p_cputype = imgp->ip_origcputype;
1427 	p->p_cpusubtype = imgp->ip_origcpusubtype;
1428 	proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1429 
1430 	vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1431 	vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1432 	vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1433 
1434 #if XNU_TARGET_OS_OSX
1435 	if (proc_platform(p) == PLATFORM_IOS) {
1436 		assert(vm_map_is_alien(map));
1437 	} else {
1438 		assert(!vm_map_is_alien(map));
1439 	}
1440 #endif /* XNU_TARGET_OS_OSX */
1441 	proc_unlock(p);
1442 
1443 	/*
1444 	 * Setup runtime mitigations.
1445 	 */
1446 	if ((error = exec_setup_runtime_mitigations(imgp, &load_result, current_task(), new_task, map, p)) != 0) {
1447 		set_proc_name(imgp, p);
1448 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1449 		if (bootarg_execfailurereports) {
1450 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1451 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1452 		}
1453 		/* release new address space since we won't use it */
1454 		imgp->ip_free_map = map;
1455 		map = VM_MAP_NULL;
1456 		goto badtoolate;
1457 	}
1458 
1459 	/*
1460 	 * Set code-signing flags if this binary is signed, or if parent has
1461 	 * requested them on exec.
1462 	 */
1463 	if (load_result.csflags & CS_VALID) {
1464 		imgp->ip_csflags |= load_result.csflags &
1465 		    (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1466 		    CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1467 		    CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1468 		    CS_ENTITLEMENT_FLAGS |
1469 		    CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1470 	} else {
1471 		imgp->ip_csflags &= ~CS_VALID;
1472 	}
1473 
1474 	if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1475 		imgp->ip_csflags |= CS_HARD;
1476 	}
1477 	if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1478 		imgp->ip_csflags |= CS_KILL;
1479 	}
1480 	if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1481 		imgp->ip_csflags |= CS_ENFORCEMENT;
1482 	}
1483 	if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1484 		if (proc_getcsflags(p) & CS_INSTALLER) {
1485 			imgp->ip_csflags |= CS_INSTALLER;
1486 		}
1487 		if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1488 			imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1489 		}
1490 		if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1491 			imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1492 		}
1493 	}
1494 
1495 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1496 	/*
1497 	 * ptrauth version 0 is a preview ABI.  Developers can opt into running
1498 	 * their own arm64e binaries for local testing, with the understanding
1499 	 * that future OSes may break ABI.
1500 	 */
1501 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1502 	    CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1503 	    !load_result.platform_binary &&
1504 	    !bootarg_arm64e_preview_abi) {
1505 		static bool logged_once = false;
1506 		set_proc_name(imgp, p);
1507 
1508 		printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1509 		if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1510 			printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1511 		}
1512 
1513 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1514 		if (bootarg_execfailurereports) {
1515 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1516 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1517 		}
1518 
1519 		/* release new address space since we won't use it */
1520 		imgp->ip_free_map = map;
1521 		map = VM_MAP_NULL;
1522 		goto badtoolate;
1523 	}
1524 
1525 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1526 	    imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1527 	    load_result.platform_binary &&
1528 	    (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1529 		set_proc_name(imgp, p);
1530 		printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
1531 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1532 		if (bootarg_execfailurereports) {
1533 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1534 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1535 		}
1536 
1537 		/* release new address space since we won't use it */
1538 		imgp->ip_free_map = map;
1539 		map = VM_MAP_NULL;
1540 		goto badtoolate;
1541 	}
1542 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1543 
1544 
1545 
1546 	/*
1547 	 * Set up the shared cache region in the new process.
1548 	 *
1549 	 * Normally there is a single shared region per architecture.
1550 	 * However on systems with Pointer Authentication, we can create
1551 	 * multiple shared caches with the amount of sharing determined
1552 	 * by team-id or entitlement. Inherited shared region IDs are used
1553 	 * for system processes that need to match and be able to inspect
1554 	 * a pre-existing task.
1555 	 */
1556 	int cpu_subtype = 0;     /* all cpu_subtypes use the same shared region */
1557 #if __has_feature(ptrauth_calls)
1558 	char *shared_region_id = NULL;
1559 	size_t len;
1560 	char *base;
1561 	const char *cbase;
1562 #define HARDENED_RUNTIME_CONTENT_ID "C-"
1563 #define TEAM_ID_PREFIX "T-"
1564 #define ENTITLE_PREFIX "E-"
1565 #define SR_PREFIX_LEN  2
1566 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1567 
1568 	if (cpu_type() == CPU_TYPE_ARM64 &&
1569 	    arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1570 	    (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1571 		assertf(p->p_cputype == CPU_TYPE_ARM64,
1572 		    "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1573 		    p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1574 
1575 		/*
1576 		 * arm64e uses pointer authentication, so request a separate
1577 		 * shared region for this CPU subtype.
1578 		 */
1579 		cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1580 
1581 		/*
1582 		 * Determine which shared cache to select based on being told,
1583 		 * matching a team-id or matching an entitlement.
1584 		 */
1585 		if (load_result.hardened_runtime_binary & BrowserWebContentEntitlementMask) {
1586 			len = sizeof(HARDENED_RUNTIME_CONTENT_ID);
1587 			shared_region_id = kalloc_data(len, Z_WAITOK | Z_NOFAIL);
1588 			strlcpy(shared_region_id, HARDENED_RUNTIME_CONTENT_ID, len);
1589 		} else if (imgp->ip_inherited_shared_region_id) {
1590 			len = strlen(imgp->ip_inherited_shared_region_id);
1591 			shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1592 			memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1593 		} else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1594 			len = strlen(cbase);
1595 			if (vm_shared_region_per_team_id) {
1596 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1597 				    Z_WAITOK | Z_NOFAIL);
1598 				memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1599 				memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1600 			}
1601 		} else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1602 		    (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1603 			len = strlen(base);
1604 			if (vm_shared_region_by_entitlement) {
1605 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1606 				    Z_WAITOK | Z_NOFAIL);
1607 				memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1608 				memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1609 			}
1610 			/* Discard the copy of the entitlement */
1611 			kfree_data(base, len + 1);
1612 		}
1613 	}
1614 
1615 	if (imgp->ip_flags & IMGPF_RESLIDE) {
1616 		reslide = TRUE;
1617 	}
1618 
1619 	/* use "" as the default shared_region_id */
1620 	if (shared_region_id == NULL) {
1621 		shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1622 	}
1623 
1624 	/* ensure there's a unique pointer signing key for this shared_region_id */
1625 	shared_region_key_alloc(shared_region_id,
1626 	    imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1627 	task_set_shared_region_id(task, shared_region_id);
1628 	shared_region_id = NULL;
1629 #endif /* __has_feature(ptrauth_calls) */
1630 
1631 #if CONFIG_ROSETTA
1632 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1633 		OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
1634 	} else if (p->p_flag & P_TRANSLATED) {
1635 		OSBitAndAtomic(~P_TRANSLATED, &p->p_flag);
1636 	}
1637 #endif
1638 
1639 	int cputype = cpu_type();
1640 
1641 	uint32_t rsr_version = 0;
1642 #if XNU_TARGET_OS_OSX
1643 	if (vnode_is_rsr(imgp->ip_vp)) {
1644 		rsr_version = rsr_get_version();
1645 		os_atomic_or(&p->p_ladvflag, P_RSR, relaxed);
1646 		os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_ALTLINK, relaxed);
1647 	}
1648 #endif /* XNU_TARGET_OS_OSX */
1649 
1650 	error = vm_map_exec(map, task, load_result.is_64bit_addr,
1651 	    (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide,
1652 	    (imgp->ip_flags & IMGPF_DRIVER) != 0,
1653 	    rsr_version);
1654 
1655 	if (error) {
1656 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1657 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAP_EXEC_FAILURE, 0, 0);
1658 
1659 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAP_EXEC_FAILURE);
1660 		if (bootarg_execfailurereports) {
1661 			set_proc_name(imgp, p);
1662 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1663 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1664 		}
1665 		/* release new address space since we won't use it */
1666 		imgp->ip_free_map = map;
1667 		map = VM_MAP_NULL;
1668 		goto badtoolate;
1669 	}
1670 
1671 	/*
1672 	 * Close file descriptors which specify close-on-exec.
1673 	 */
1674 	fdt_exec(p, vfs_context_ucred(imgp->ip_vfs_context),
1675 	    psa != NULL ? psa->psa_flags : 0, imgp->ip_new_thread, exec);
1676 
1677 	/*
1678 	 * deal with set[ug]id.
1679 	 */
1680 	error = exec_handle_sugid(imgp);
1681 	if (error) {
1682 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1683 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1684 
1685 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1686 		if (bootarg_execfailurereports) {
1687 			set_proc_name(imgp, p);
1688 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1689 		}
1690 
1691 		/* release new address space since we won't use it */
1692 		imgp->ip_free_map = map;
1693 		map = VM_MAP_NULL;
1694 		goto badtoolate;
1695 	}
1696 
1697 	/*
1698 	 * Commit to new map.
1699 	 *
1700 	 * Swap the new map for the old for target task, which consumes
1701 	 * our new map reference but each leaves us responsible for the
1702 	 * old_map reference.  That lets us get off the pmap associated
1703 	 * with it, and then we can release it.
1704 	 *
1705 	 * The map needs to be set on the target task which is different
1706 	 * than current task, thus swap_task_map is used instead of
1707 	 * vm_map_switch.
1708 	 */
1709 	old_map = swap_task_map(task, thread, map);
1710 #if MACH_ASSERT
1711 	/*
1712 	 * Reset the pmap's process info to prevent ledger checks
1713 	 * which might fail due to the ledgers being shared between
1714 	 * the old and new pmaps.
1715 	 */
1716 	vm_map_pmap_set_process(old_map, -1, "<old_map>");
1717 #endif /* MACH_ASSERT */
1718 	imgp->ip_free_map = old_map;
1719 	old_map = NULL;
1720 
1721 	lret = activate_exec_state(task, p, thread, &load_result);
1722 	if (lret != KERN_SUCCESS) {
1723 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1724 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1725 
1726 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1727 		if (bootarg_execfailurereports) {
1728 			set_proc_name(imgp, p);
1729 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1730 		}
1731 
1732 		goto badtoolate;
1733 	}
1734 
1735 	/*
1736 	 * deal with voucher on exec-calling thread.
1737 	 */
1738 	if (imgp->ip_new_thread == NULL) {
1739 		thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1740 	}
1741 
1742 	/* Make sure we won't interrupt ourself signalling a partial process */
1743 	if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1744 		psignal(p, SIGTRAP);
1745 	}
1746 
1747 	if (load_result.unixproc &&
1748 	    create_unix_stack(get_task_map(task),
1749 	    &load_result,
1750 	    p) != KERN_SUCCESS) {
1751 		error = load_return_to_errno(LOAD_NOSPACE);
1752 
1753 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1754 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1755 
1756 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1757 		if (bootarg_execfailurereports) {
1758 			set_proc_name(imgp, p);
1759 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1760 		}
1761 
1762 		goto badtoolate;
1763 	}
1764 
1765 	if (load_result.hardened_runtime_binary) {
1766 		if (cs_debug) {
1767 			printf("setting hardened runtime with entitlement mask= "
1768 			    "0x%x on task: pid = %d\n",
1769 			    load_result.hardened_runtime_binary,
1770 			    proc_getpid(p));
1771 		}
1772 		task_set_hardened_runtime(task, true);
1773 	}
1774 
1775 	/*
1776 	 * The load result will have already been munged by AMFI to include the
1777 	 * platform binary flag if boot-args dictated it (AMFI will mark anything
1778 	 * that doesn't go through the upcall path as a platform binary if its
1779 	 * enforcement is disabled).
1780 	 */
1781 	if (load_result.platform_binary) {
1782 		if (cs_debug) {
1783 			printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1784 		}
1785 
1786 		/*
1787 		 * We must use 'task' here because the proc's task has not yet been
1788 		 * switched to the new one.
1789 		 */
1790 		task_set_platform_binary(task, TRUE);
1791 	} else {
1792 		if (cs_debug) {
1793 			printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1794 		}
1795 
1796 		task_set_platform_binary(task, FALSE);
1797 	}
1798 
1799 #if XNU_TARGET_OS_OSX
1800 	/* Disable mach hardening for all 1P tasks which load 3P plugins */
1801 	if (imgp->ip_flags & IMGPF_3P_PLUGINS) {
1802 		if (cs_debug) {
1803 			printf("Disabling some mach hardening on task due to 3P plugins: pid = %d\n", proc_getpid(p));
1804 		}
1805 		task_disable_mach_hardening(task);
1806 	}
1807 #if DEVELOPMENT || DEBUG
1808 	/* Disable mach hardening for all tasks if amfi_get_out_of_my_way is set.
1809 	 * Customers will have to turn SIP off to use this boot-arg, and so this is
1810 	 * only needed internally since we disable this feature when SIP is off. */
1811 	if (AMFI_bootarg_disable_mach_hardening) {
1812 		if (cs_debug) {
1813 			printf("Disabling some mach hardening on task due to AMFI boot-args: pid = %d\n", proc_getpid(p));
1814 		}
1815 		task_disable_mach_hardening(task);
1816 	}
1817 #endif /* DEVELOPMENT || DEBUG */
1818 #endif /* XNU_TARGET_OS_OSX */
1819 
1820 	/*
1821 	 * Set starting EXC_GUARD and control port behavior for task now that
1822 	 * platform and hardened runtime is set. Use the name directly from imgp since we haven't
1823 	 * set_proc_name() yet. Also make control port for the task and main thread
1824 	 * immovable/pinned based on task's option.
1825 	 *
1826 	 * Must happen before main thread port copyout in exc_add_apple_strings.
1827 	 */
1828 	task_set_exc_guard_ctrl_port_default(task, thread,
1829 	    imgp->ip_ndp->ni_cnd.cn_nameptr,
1830 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1831 	    proc_is_simulated(p),
1832 	    load_result.ip_platform,
1833 	    load_result.lr_sdk);
1834 
1835 	error = exec_add_apple_strings(imgp, &load_result, task);     /* copies out main thread port */
1836 
1837 	if (error) {
1838 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1839 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
1840 
1841 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
1842 		if (bootarg_execfailurereports) {
1843 			set_proc_name(imgp, p);
1844 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1845 		}
1846 		goto badtoolate;
1847 	}
1848 
1849 	/* Switch to target task's map to copy out strings */
1850 	switch_ctx = vm_map_switch_to(get_task_map(task));
1851 
1852 	if (load_result.unixproc) {
1853 		user_addr_t     ap;
1854 
1855 		/*
1856 		 * Copy the strings area out into the new process address
1857 		 * space.
1858 		 */
1859 		ap = p->user_stack;
1860 		error = exec_copyout_strings(imgp, &ap);
1861 		if (error) {
1862 			vm_map_switch_back(switch_ctx);
1863 
1864 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1865 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
1866 
1867 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
1868 			if (bootarg_execfailurereports) {
1869 				set_proc_name(imgp, p);
1870 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1871 			}
1872 			goto badtoolate;
1873 		}
1874 		/* Set the stack */
1875 		thread_setuserstack(thread, ap);
1876 	}
1877 
1878 	if (load_result.dynlinker || load_result.is_rosetta) {
1879 		user_addr_t        ap;
1880 		int                     new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
1881 
1882 		/* Adjust the stack */
1883 		ap = thread_adjuserstack(thread, -new_ptr_size);
1884 		error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
1885 
1886 		if (error) {
1887 			vm_map_switch_back(switch_ctx);
1888 
1889 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1890 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
1891 
1892 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
1893 			if (bootarg_execfailurereports) {
1894 				set_proc_name(imgp, p);
1895 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1896 			}
1897 			goto badtoolate;
1898 		}
1899 		error = task_set_dyld_info(task, load_result.all_image_info_addr,
1900 		    load_result.all_image_info_size, false);
1901 		if (error) {
1902 			vm_map_switch_back(switch_ctx);
1903 
1904 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1905 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
1906 
1907 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1908 			if (bootarg_execfailurereports) {
1909 				set_proc_name(imgp, p);
1910 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1911 			}
1912 			error = EINVAL;
1913 			goto badtoolate;
1914 		}
1915 	} else {
1916 		/*
1917 		 * No dyld or rosetta loaded, set the TF_DYLD_ALL_IMAGE_FINAL bit on task.
1918 		 */
1919 		error = task_set_dyld_info(task, MACH_VM_MIN_ADDRESS,
1920 		    0, true);
1921 		if (error) {
1922 			vm_map_switch_back(switch_ctx);
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_SET_DYLD_INFO, 0, 0);
1926 
1927 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1928 			if (bootarg_execfailurereports) {
1929 				set_proc_name(imgp, p);
1930 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1931 			}
1932 			error = EINVAL;
1933 			goto badtoolate;
1934 		}
1935 	}
1936 
1937 #if CONFIG_ROSETTA
1938 	if (load_result.is_rosetta) {
1939 		// Add an fd for the executable file for Rosetta's use
1940 		int main_binary_fd;
1941 		struct fileproc *fp;
1942 
1943 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &main_binary_fd);
1944 		if (error) {
1945 			vm_map_switch_back(switch_ctx);
1946 
1947 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1948 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1949 
1950 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1951 			if (bootarg_execfailurereports) {
1952 				set_proc_name(imgp, p);
1953 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1954 			}
1955 			goto badtoolate;
1956 		}
1957 
1958 		error = VNOP_OPEN(imgp->ip_vp, FREAD, imgp->ip_vfs_context);
1959 		if (error) {
1960 			vm_map_switch_back(switch_ctx);
1961 
1962 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1963 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1964 
1965 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1966 			if (bootarg_execfailurereports) {
1967 				set_proc_name(imgp, p);
1968 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1969 			}
1970 			goto cleanup_rosetta_fp;
1971 		}
1972 
1973 		fp->fp_glob->fg_flag = FREAD;
1974 		fp->fp_glob->fg_ops = &vnops;
1975 		fp_set_data(fp, imgp->ip_vp);
1976 
1977 		proc_fdlock(p);
1978 		procfdtbl_releasefd(p, main_binary_fd, NULL);
1979 		fp_drop(p, main_binary_fd, fp, 1);
1980 		proc_fdunlock(p);
1981 
1982 		vnode_ref(imgp->ip_vp);
1983 
1984 		// Pass the dyld load address, main binary fd, and dyld fd on the stack
1985 		uint64_t ap = thread_adjuserstack(thread, -24);
1986 
1987 		error = copyoutptr((user_addr_t)load_result.dynlinker_fd, ap, 8);
1988 		if (error) {
1989 			vm_map_switch_back(switch_ctx);
1990 
1991 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1992 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1993 
1994 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1995 			if (bootarg_execfailurereports) {
1996 				set_proc_name(imgp, p);
1997 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1998 			}
1999 			goto cleanup_rosetta_fp;
2000 		}
2001 
2002 		error = copyoutptr(load_result.dynlinker_mach_header, ap + 8, 8);
2003 		if (error) {
2004 			vm_map_switch_back(switch_ctx);
2005 
2006 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2007 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
2008 
2009 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
2010 			if (bootarg_execfailurereports) {
2011 				set_proc_name(imgp, p);
2012 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2013 			}
2014 			goto cleanup_rosetta_fp;
2015 		}
2016 
2017 		error = copyoutptr((user_addr_t)main_binary_fd, ap + 16, 8);
2018 		if (error) {
2019 			vm_map_switch_back(switch_ctx);
2020 
2021 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2022 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
2023 
2024 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
2025 			if (bootarg_execfailurereports) {
2026 				set_proc_name(imgp, p);
2027 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2028 			}
2029 			goto cleanup_rosetta_fp;
2030 		}
2031 
2032 cleanup_rosetta_fp:
2033 		if (error) {
2034 			fp_free(p, load_result.dynlinker_fd, load_result.dynlinker_fp);
2035 			fp_free(p, main_binary_fd, fp);
2036 			goto badtoolate;
2037 		}
2038 	}
2039 
2040 #endif
2041 
2042 	/* Avoid immediate VM faults back into kernel */
2043 	exec_prefault_data(p, imgp, &load_result);
2044 
2045 	vm_map_switch_back(switch_ctx);
2046 
2047 	/*
2048 	 * Reset signal state.
2049 	 */
2050 	execsigs(p, thread);
2051 
2052 	/*
2053 	 * need to cancel async IO requests that can be cancelled and wait for those
2054 	 * already active.  MAY BLOCK!
2055 	 */
2056 	_aio_exec( p );
2057 
2058 #if SYSV_SHM
2059 	/* FIXME: Till vmspace inherit is fixed: */
2060 	if (!vfexec && p->vm_shm) {
2061 		shmexec(p);
2062 	}
2063 #endif
2064 #if SYSV_SEM
2065 	/* Clean up the semaphores */
2066 	semexit(p);
2067 #endif
2068 
2069 	/*
2070 	 * Remember file name for accounting.
2071 	 */
2072 	p->p_acflag &= ~AFORK;
2073 
2074 	set_proc_name(imgp, p);
2075 
2076 #if CONFIG_SECLUDED_MEMORY
2077 	if (secluded_for_apps &&
2078 	    load_result.platform_binary) {
2079 		if (strncmp(p->p_name,
2080 		    "Camera",
2081 		    sizeof(p->p_name)) == 0) {
2082 			task_set_could_use_secluded_mem(task, TRUE);
2083 		} else {
2084 			task_set_could_use_secluded_mem(task, FALSE);
2085 		}
2086 		if (strncmp(p->p_name,
2087 		    "mediaserverd",
2088 		    sizeof(p->p_name)) == 0) {
2089 			task_set_could_also_use_secluded_mem(task, TRUE);
2090 		}
2091 		if (strncmp(p->p_name,
2092 		    "cameracaptured",
2093 		    sizeof(p->p_name)) == 0) {
2094 			task_set_could_also_use_secluded_mem(task, TRUE);
2095 		}
2096 	}
2097 #endif /* CONFIG_SECLUDED_MEMORY */
2098 
2099 #if __arm64__
2100 	if (load_result.legacy_footprint) {
2101 		task_set_legacy_footprint(task);
2102 	}
2103 #endif /* __arm64__ */
2104 
2105 	pal_dbg_set_task_name(task);
2106 
2107 #if DEVELOPMENT || DEBUG
2108 	/*
2109 	 * Update the pid an proc name for importance base if any
2110 	 */
2111 	task_importance_update_owner_info(task);
2112 #endif
2113 
2114 	proc_setexecutableuuid(p, &load_result.uuid[0]);
2115 
2116 #if CONFIG_DTRACE
2117 	dtrace_proc_exec(p);
2118 #endif
2119 
2120 	if (kdebug_enable) {
2121 		long args[4] = {};
2122 
2123 		uintptr_t fsid = 0, fileid = 0;
2124 		if (imgp->ip_vattr) {
2125 			uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
2126 			fsid   = (uintptr_t)fsid64;
2127 			fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
2128 			// check for (unexpected) overflow and trace zero in that case
2129 			if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
2130 				fsid = fileid = 0;
2131 			}
2132 		}
2133 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
2134 		    (uintptr_t)thread_tid(thread));
2135 
2136 		extern void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
2137 		kdebug_proc_name_args(p, args);
2138 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
2139 		    args[2], args[3], (uintptr_t)thread_tid(thread));
2140 	}
2141 
2142 
2143 	/*
2144 	 * If posix_spawned with the START_SUSPENDED flag, stop the
2145 	 * process before it runs.
2146 	 */
2147 	if (imgp->ip_px_sa != NULL) {
2148 		psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
2149 		if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
2150 			proc_lock(p);
2151 			p->p_stat = SSTOP;
2152 			proc_unlock(p);
2153 			(void) task_suspend_internal(task);
2154 		}
2155 	}
2156 
2157 	/*
2158 	 * mark as execed
2159 	 */
2160 	OSBitOrAtomic(P_EXEC, &p->p_flag);
2161 	proc_resetregister(p);
2162 	if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
2163 		proc_lock(p);
2164 		p->p_lflag &= ~P_LPPWAIT;
2165 		proc_unlock(p);
2166 		wakeup((caddr_t)p->p_pptr);
2167 	}
2168 
2169 	/*
2170 	 * Set up dext coredumps on kernel panic.
2171 	 * This requires the following:
2172 	 * - dext_panic_coredump=1 boot-arg (enabled by default on DEVELOPMENT, DEBUG and certain Seed builds)
2173 	 * - process must be a driver
2174 	 * - process must have the com.apple.private.enable-coredump-on-panic entitlement, and the
2175 	 *   entitlement has a string value.
2176 	 * - process must have the com.apple.private.enable-coredump-on-panic-seed-privacy-approved
2177 	 *   entitlement (Seed builds only).
2178 	 *
2179 	 * The core dump file name is formatted with the entitlement string value, followed by a hyphen
2180 	 * and the process PID.
2181 	 */
2182 	if (enable_dext_coredumps_on_panic &&
2183 	    (imgp->ip_flags & IMGPF_DRIVER) != 0 &&
2184 	    (userspace_coredump_name = IOVnodeGetEntitlement(imgp->ip_vp,
2185 	    (int64_t)imgp->ip_arch_offset, USERSPACE_COREDUMP_PANIC_ENTITLEMENT)) != NULL) {
2186 		size_t userspace_coredump_name_len = strlen(userspace_coredump_name);
2187 
2188 		char core_name[MACH_CORE_FILEHEADER_NAMELEN];
2189 		/* 16 - NULL char - strlen("-") - maximum of 5 digits for pid */
2190 		snprintf(core_name, MACH_CORE_FILEHEADER_NAMELEN, "%.9s-%d", userspace_coredump_name, proc_getpid(p));
2191 
2192 		kern_register_userspace_coredump(task, core_name);
2193 
2194 		/* Discard the copy of the entitlement */
2195 		kfree_data(userspace_coredump_name, userspace_coredump_name_len + 1);
2196 		userspace_coredump_name = NULL;
2197 	}
2198 
2199 	goto done;
2200 
2201 badtoolate:
2202 	/* Don't allow child process to execute any instructions */
2203 	if (!spawn) {
2204 		{
2205 			assert(exec_failure_reason != OS_REASON_NULL);
2206 			if (bootarg_execfailurereports) {
2207 				set_proc_name(imgp, current_proc());
2208 			}
2209 			psignal_with_reason(current_proc(), SIGKILL, exec_failure_reason);
2210 			exec_failure_reason = OS_REASON_NULL;
2211 
2212 			if (exec) {
2213 				/* Terminate the exec copy task */
2214 				task_terminate_internal(task);
2215 			}
2216 		}
2217 
2218 		/* We can't stop this system call at this point, so just pretend we succeeded */
2219 		error = 0;
2220 	} else {
2221 		os_reason_free(exec_failure_reason);
2222 		exec_failure_reason = OS_REASON_NULL;
2223 	}
2224 
2225 done:
2226 	if (load_result.threadstate) {
2227 		kfree_data(load_result.threadstate, load_result.threadstate_sz);
2228 		load_result.threadstate = NULL;
2229 	}
2230 
2231 bad:
2232 	/* If we hit this, we likely would have leaked an exit reason */
2233 	assert(exec_failure_reason == OS_REASON_NULL);
2234 	return error;
2235 }
2236 
2237 
2238 
2239 
2240 /*
2241  * Our image activator table; this is the table of the image types we are
2242  * capable of loading.  We list them in order of preference to ensure the
2243  * fastest image load speed.
2244  *
2245  * XXX hardcoded, for now; should use linker sets
2246  */
2247 struct execsw {
2248 	int(*const ex_imgact)(struct image_params *);
2249 	const char *ex_name;
2250 }const execsw[] = {
2251 	{ exec_mach_imgact, "Mach-o Binary" },
2252 	{ exec_fat_imgact, "Fat Binary" },
2253 	{ exec_shell_imgact, "Interpreter Script" },
2254 	{ NULL, NULL}
2255 };
2256 
2257 
2258 /*
2259  * exec_activate_image
2260  *
2261  * Description:	Iterate through the available image activators, and activate
2262  *		the image associated with the imgp structure.  We start with
2263  *		the activator for Mach-o binaries followed by that for Fat binaries
2264  *		for Interpreter scripts.
2265  *
2266  * Parameters:	struct image_params *	Image parameter block
2267  *
2268  * Returns:	0			Success
2269  *		ENOEXEC			No activator for image.
2270  *		EBADEXEC		The executable is corrupt/unknown
2271  *	execargs_alloc:EINVAL		Invalid argument
2272  *	execargs_alloc:EACCES		Permission denied
2273  *	execargs_alloc:EINTR		Interrupted function
2274  *	execargs_alloc:ENOMEM		Not enough space
2275  *	exec_save_path:EFAULT		Bad address
2276  *	exec_save_path:ENAMETOOLONG	Filename too long
2277  *	exec_check_permissions:EACCES	Permission denied
2278  *	exec_check_permissions:ENOEXEC	Executable file format error
2279  *	exec_check_permissions:ETXTBSY	Text file busy [misuse of error code]
2280  *	exec_check_permissions:???
2281  *	namei:???
2282  *	vn_rdwr:???			[anything vn_rdwr can return]
2283  *	<ex_imgact>:???			[anything an imgact can return]
2284  *	EDEADLK				Process is being terminated
2285  */
2286 static int
exec_activate_image(struct image_params * imgp)2287 exec_activate_image(struct image_params *imgp)
2288 {
2289 	struct nameidata *ndp = NULL;
2290 	const char *excpath;
2291 	int error;
2292 	int resid;
2293 	int once = 1;   /* save SGUID-ness for interpreted files */
2294 	int i;
2295 	int itercount = 0;
2296 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2297 
2298 	/*
2299 	 * For exec, the translock needs to be taken on old proc and not
2300 	 * on new shadow proc.
2301 	 */
2302 	if (imgp->ip_flags & IMGPF_EXEC) {
2303 		p = current_proc();
2304 	}
2305 
2306 	error = execargs_alloc(imgp);
2307 	if (error) {
2308 		goto bad_notrans;
2309 	}
2310 
2311 	error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
2312 	if (error) {
2313 		goto bad_notrans;
2314 	}
2315 
2316 	/* Use excpath, which contains the copyin-ed exec path */
2317 	DTRACE_PROC1(exec, uintptr_t, excpath);
2318 
2319 	ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2320 
2321 	NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
2322 	    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2323 
2324 again:
2325 	error = namei(ndp);
2326 	if (error) {
2327 		if (error == ERESTART) {
2328 			error = EINTR;
2329 		}
2330 		goto bad_notrans;
2331 	}
2332 	imgp->ip_ndp = ndp;     /* successful namei(); call nameidone() later */
2333 	imgp->ip_vp = ndp->ni_vp;       /* if set, need to vnode_put() at some point */
2334 
2335 	/*
2336 	 * Before we start the transition from binary A to binary B, make
2337 	 * sure another thread hasn't started exiting the process.  We grab
2338 	 * the proc lock to check p_lflag initially, and the transition
2339 	 * mechanism ensures that the value doesn't change after we release
2340 	 * the lock.
2341 	 */
2342 	proc_lock(p);
2343 	if (p->p_lflag & P_LEXIT) {
2344 		error = EDEADLK;
2345 		proc_unlock(p);
2346 		goto bad_notrans;
2347 	}
2348 	error = proc_transstart(p, 1, 0);
2349 	proc_unlock(p);
2350 	if (error) {
2351 		goto bad_notrans;
2352 	}
2353 
2354 	error = exec_check_permissions(imgp);
2355 	if (error) {
2356 		goto bad;
2357 	}
2358 
2359 	/* Copy; avoid invocation of an interpreter overwriting the original */
2360 	if (once) {
2361 		once = 0;
2362 		*imgp->ip_origvattr = *imgp->ip_vattr;
2363 	}
2364 
2365 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
2366 	    UIO_SYSSPACE, IO_NODELOCKED,
2367 	    vfs_context_ucred(imgp->ip_vfs_context),
2368 	    &resid, vfs_context_proc(imgp->ip_vfs_context));
2369 	if (error) {
2370 		goto bad;
2371 	}
2372 
2373 	if (resid) {
2374 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
2375 	}
2376 
2377 encapsulated_binary:
2378 	/* Limit the number of iterations we will attempt on each binary */
2379 	if (++itercount > EAI_ITERLIMIT) {
2380 		error = EBADEXEC;
2381 		goto bad;
2382 	}
2383 	error = -1;
2384 	for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
2385 		error = (*execsw[i].ex_imgact)(imgp);
2386 
2387 		switch (error) {
2388 		/* case -1: not claimed: continue */
2389 		case -2:                /* Encapsulated binary, imgp->ip_XXX set for next iteration */
2390 			goto encapsulated_binary;
2391 
2392 		case -3:                /* Interpreter */
2393 #if CONFIG_MACF
2394 			/*
2395 			 * Copy the script label for later use. Note that
2396 			 * the label can be different when the script is
2397 			 * actually read by the interpreter.
2398 			 */
2399 			if (imgp->ip_scriptlabelp) {
2400 				mac_vnode_label_free(imgp->ip_scriptlabelp);
2401 				imgp->ip_scriptlabelp = NULL;
2402 			}
2403 			imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
2404 			if (imgp->ip_scriptlabelp == NULL) {
2405 				error = ENOMEM;
2406 				break;
2407 			}
2408 			mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
2409 			    imgp->ip_scriptlabelp);
2410 
2411 			/*
2412 			 * Take a ref of the script vnode for later use.
2413 			 */
2414 			if (imgp->ip_scriptvp) {
2415 				vnode_put(imgp->ip_scriptvp);
2416 				imgp->ip_scriptvp = NULLVP;
2417 			}
2418 			if (vnode_getwithref(imgp->ip_vp) == 0) {
2419 				imgp->ip_scriptvp = imgp->ip_vp;
2420 			}
2421 #endif
2422 
2423 			nameidone(ndp);
2424 
2425 			vnode_put(imgp->ip_vp);
2426 			imgp->ip_vp = NULL;     /* already put */
2427 			imgp->ip_ndp = NULL; /* already nameidone */
2428 
2429 			/* Use excpath, which exec_shell_imgact reset to the interpreter */
2430 			NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
2431 			    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2432 
2433 			proc_transend(p, 0);
2434 			goto again;
2435 
2436 		default:
2437 			break;
2438 		}
2439 	}
2440 
2441 	if (error == -1) {
2442 		error = ENOEXEC;
2443 	} else if (error == 0) {
2444 		if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
2445 			AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
2446 		}
2447 
2448 		/*
2449 		 * Call out to allow 3rd party notification of exec.
2450 		 * Ignore result of kauth_authorize_fileop call.
2451 		 */
2452 		if (kauth_authorize_fileop_has_listeners()) {
2453 			kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
2454 			    KAUTH_FILEOP_EXEC,
2455 			    (uintptr_t)ndp->ni_vp, 0);
2456 		}
2457 	}
2458 bad:
2459 	proc_transend(p, 0);
2460 
2461 bad_notrans:
2462 	if (imgp->ip_strings) {
2463 		execargs_free(imgp);
2464 	}
2465 	if (imgp->ip_ndp) {
2466 		nameidone(imgp->ip_ndp);
2467 	}
2468 	kfree_type(struct nameidata, ndp);
2469 
2470 	return error;
2471 }
2472 
2473 
2474 /*
2475  * exec_validate_spawnattr_policy
2476  *
2477  * Description: Validates the entitlements required to set the apptype.
2478  *
2479  * Parameters:  int psa_apptype         posix spawn attribute apptype
2480  *
2481  * Returns:     0                       Success
2482  *              EPERM                   Failure
2483  */
2484 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)2485 exec_validate_spawnattr_policy(int psa_apptype)
2486 {
2487 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2488 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2489 		if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
2490 			if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
2491 				return EPERM;
2492 			}
2493 		}
2494 	}
2495 
2496 	return 0;
2497 }
2498 
2499 /*
2500  * exec_handle_spawnattr_policy
2501  *
2502  * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
2503  *
2504  * Parameters:  proc_t p                process to apply attributes to
2505  *              int psa_apptype         posix spawn attribute apptype
2506  *
2507  * Returns:     0                       Success
2508  */
2509 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)2510 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2511     task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2512 {
2513 	int apptype     = TASK_APPTYPE_NONE;
2514 	int qos_clamp   = THREAD_QOS_UNSPECIFIED;
2515 	task_role_t role = TASK_UNSPECIFIED;
2516 
2517 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2518 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2519 
2520 		switch (proctype) {
2521 		case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2522 			apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2523 			break;
2524 		case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2525 			apptype = TASK_APPTYPE_DAEMON_STANDARD;
2526 			break;
2527 		case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2528 			apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2529 			break;
2530 		case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2531 			apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2532 			break;
2533 		case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2534 			apptype = TASK_APPTYPE_APP_DEFAULT;
2535 			break;
2536 		case POSIX_SPAWN_PROC_TYPE_DRIVER:
2537 			apptype = TASK_APPTYPE_DRIVER;
2538 			break;
2539 		default:
2540 			apptype = TASK_APPTYPE_NONE;
2541 			/* TODO: Should an invalid value here fail the spawn? */
2542 			break;
2543 		}
2544 	}
2545 
2546 	if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2547 		switch (psa_qos_clamp) {
2548 		case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2549 			qos_clamp = THREAD_QOS_UTILITY;
2550 			break;
2551 		case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2552 			qos_clamp = THREAD_QOS_BACKGROUND;
2553 			break;
2554 		case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2555 			qos_clamp = THREAD_QOS_MAINTENANCE;
2556 			break;
2557 		default:
2558 			qos_clamp = THREAD_QOS_UNSPECIFIED;
2559 			/* TODO: Should an invalid value here fail the spawn? */
2560 			break;
2561 		}
2562 	}
2563 
2564 	if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2565 		proc_darwin_role_to_task_role(psa_darwin_role, &role);
2566 	}
2567 
2568 	if (apptype != TASK_APPTYPE_NONE ||
2569 	    qos_clamp != THREAD_QOS_UNSPECIFIED ||
2570 	    role != TASK_UNSPECIFIED ||
2571 	    port_actions->portwatch_count) {
2572 		proc_set_task_spawnpolicy(proc_task(p), thread, apptype, qos_clamp, role,
2573 		    port_actions->portwatch_array, port_actions->portwatch_count);
2574 	}
2575 
2576 	if (port_actions->registered_count) {
2577 		if (_kernelrpc_mach_ports_register3(proc_task(p),
2578 		    port_actions->registered_array[0],
2579 		    port_actions->registered_array[1],
2580 		    port_actions->registered_array[2])) {
2581 			return EINVAL;
2582 		}
2583 		/* mach_ports_register() consumed the array */
2584 		bzero(port_actions->registered_array,
2585 		    sizeof(port_actions->registered_array));
2586 		port_actions->registered_count = 0;
2587 	}
2588 
2589 	return 0;
2590 }
2591 
2592 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2593 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2594 {
2595 	if (port_actions->excport_array) {
2596 		for (uint32_t i = 0; i < port_actions->exception_port_count; i++) {
2597 			ipc_port_t port = NULL;
2598 			if ((port = port_actions->excport_array[i].port) != NULL) {
2599 				ipc_port_release_send(port);
2600 			}
2601 		}
2602 		kfree_type(struct exception_port_action_t, port_actions->exception_port_count,
2603 		    port_actions->excport_array);
2604 	}
2605 
2606 	if (port_actions->portwatch_array) {
2607 		for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2608 			ipc_port_t port = NULL;
2609 			if ((port = port_actions->portwatch_array[i]) != NULL) {
2610 				ipc_port_release_send(port);
2611 			}
2612 		}
2613 		kfree_type(ipc_port_t, port_actions->portwatch_count,
2614 		    port_actions->portwatch_array);
2615 	}
2616 
2617 	for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2618 		ipc_port_t port = NULL;
2619 		if ((port = port_actions->registered_array[i]) != NULL) {
2620 			ipc_port_release_send(port);
2621 		}
2622 	}
2623 }
2624 
2625 /*
2626  * exec_handle_port_actions
2627  *
2628  * Description:	Go through the _posix_port_actions_t contents,
2629  *              calling task_set_special_port, task_set_exception_ports
2630  *              and/or audit_session_spawnjoin for the current task.
2631  *
2632  * Parameters:	struct image_params *	Image parameter block
2633  *
2634  * Returns:	0			Success
2635  *              EINVAL			Failure
2636  *              ENOTSUP			Illegal posix_spawn attr flag was set
2637  */
2638 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2639 exec_handle_port_actions(struct image_params *imgp,
2640     struct exec_port_actions *actions)
2641 {
2642 	_posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2643 #if CONFIG_AUDIT
2644 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2645 #endif
2646 	_ps_port_action_t *act = NULL;
2647 	task_t task = get_threadtask(imgp->ip_new_thread);
2648 	ipc_port_t port = NULL;
2649 	errno_t ret = 0;
2650 	int i = 0, portwatch_i = 0, registered_i = 0, excport_i = 0;
2651 	kern_return_t kr;
2652 	boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2653 	boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2654 	int ptrauth_task_port_count = 0;
2655 
2656 	for (i = 0; i < pacts->pspa_count; i++) {
2657 		act = &pacts->pspa_actions[i];
2658 
2659 		switch (act->port_type) {
2660 		case PSPA_SPECIAL:
2661 #if CONFIG_AUDIT
2662 		case PSPA_AU_SESSION:
2663 #endif
2664 			break;
2665 		case PSPA_EXCEPTION:
2666 			if (++actions->exception_port_count > TASK_MAX_EXCEPTION_PORT_COUNT) {
2667 				ret = EINVAL;
2668 				goto done;
2669 			}
2670 			break;
2671 		case PSPA_IMP_WATCHPORTS:
2672 			if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
2673 				ret = EINVAL;
2674 				goto done;
2675 			}
2676 			break;
2677 		case PSPA_REGISTERED_PORTS:
2678 			if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
2679 				ret = EINVAL;
2680 				goto done;
2681 			}
2682 			break;
2683 		case PSPA_PTRAUTH_TASK_PORT:
2684 			if (++ptrauth_task_port_count > 1) {
2685 				ret = EINVAL;
2686 				goto done;
2687 			}
2688 			break;
2689 		default:
2690 			ret = EINVAL;
2691 			goto done;
2692 		}
2693 	}
2694 
2695 	if (actions->exception_port_count) {
2696 		actions->excport_array = kalloc_type(struct exception_port_action_t,
2697 		    actions->exception_port_count, Z_WAITOK | Z_ZERO);
2698 
2699 		if (actions->excport_array == NULL) {
2700 			ret = ENOMEM;
2701 			goto done;
2702 		}
2703 	}
2704 	if (actions->portwatch_count) {
2705 		if (in_exec && task_has_watchport_boost) {
2706 			ret = EINVAL;
2707 			goto done;
2708 		}
2709 		actions->portwatch_array = kalloc_type(ipc_port_t,
2710 		    actions->portwatch_count, Z_WAITOK | Z_ZERO);
2711 		if (actions->portwatch_array == NULL) {
2712 			ret = ENOMEM;
2713 			goto done;
2714 		}
2715 	}
2716 
2717 	for (i = 0; i < pacts->pspa_count; i++) {
2718 		act = &pacts->pspa_actions[i];
2719 
2720 		if (MACH_PORT_VALID(act->new_port)) {
2721 			kr = ipc_typed_port_copyin_send(get_task_ipcspace(current_task()),
2722 			    act->new_port, IKOT_UNKNOWN, &port);
2723 
2724 			if (kr != KERN_SUCCESS) {
2725 				ret = EINVAL;
2726 				goto done;
2727 			}
2728 		} else {
2729 			/* it's NULL or DEAD */
2730 			port = CAST_MACH_NAME_TO_PORT(act->new_port);
2731 		}
2732 
2733 		switch (act->port_type) {
2734 		case PSPA_SPECIAL:
2735 			kr = task_set_special_port(task, act->which, port);
2736 
2737 			if (kr != KERN_SUCCESS) {
2738 				ret = EINVAL;
2739 			}
2740 			break;
2741 
2742 #if CONFIG_AUDIT
2743 		case PSPA_AU_SESSION:
2744 			ret = audit_session_spawnjoin(p, port);
2745 			if (ret) {
2746 				/* audit_session_spawnjoin() has already dropped the reference in case of error. */
2747 				goto done;
2748 			}
2749 
2750 			break;
2751 #endif
2752 		case PSPA_EXCEPTION:
2753 			assert(excport_i < actions->exception_port_count);
2754 			/* hold on to this till end of spawn */
2755 			actions->excport_array[excport_i].port_action = act;
2756 			actions->excport_array[excport_i].port = port;
2757 			excport_i++;
2758 			break;
2759 		case PSPA_IMP_WATCHPORTS:
2760 			assert(portwatch_i < actions->portwatch_count);
2761 			/* hold on to this till end of spawn */
2762 			actions->portwatch_array[portwatch_i++] = port;
2763 			break;
2764 		case PSPA_REGISTERED_PORTS:
2765 			assert(registered_i < actions->registered_count);
2766 			/* hold on to this till end of spawn */
2767 			actions->registered_array[registered_i++] = port;
2768 			break;
2769 
2770 		case PSPA_PTRAUTH_TASK_PORT:
2771 #if (DEVELOPMENT || DEBUG)
2772 #if defined(HAS_APPLE_PAC)
2773 			{
2774 				task_t ptr_auth_task = convert_port_to_task(port);
2775 
2776 				if (ptr_auth_task == TASK_NULL) {
2777 					ret = EINVAL;
2778 					break;
2779 				}
2780 
2781 				imgp->ip_inherited_shared_region_id =
2782 				    task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
2783 				    &imgp->ip_inherited_jop_pid);
2784 
2785 				/* Deallocate task ref returned by convert_port_to_task */
2786 				task_deallocate(ptr_auth_task);
2787 			}
2788 #endif /* HAS_APPLE_PAC */
2789 #endif /* (DEVELOPMENT || DEBUG) */
2790 
2791 			/* consume the port right in case of success */
2792 			ipc_port_release_send(port);
2793 			break;
2794 		default:
2795 			ret = EINVAL;
2796 			break;
2797 		}
2798 
2799 		if (ret) {
2800 			/* action failed, so release port resources */
2801 			ipc_port_release_send(port);
2802 			break;
2803 		}
2804 	}
2805 
2806 done:
2807 	if (0 != ret) {
2808 		DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2809 	}
2810 	return ret;
2811 }
2812 
2813 
2814 /*
2815  * exec_handle_exception_port_actions
2816  *
2817  * Description:	Go through the saved exception ports in exec_port_actions,
2818  *              calling task_set_exception_ports for the current Task.
2819  *              This must happen after image activation, and after exec_resettextvp()
2820  *				because task_set_exception_ports checks the `TF_PLATFORM` bit and entitlements.
2821  *
2822  * Parameters:	struct image_params *		Image parameter block
2823  *                              struct exec_port_actions *  Saved Port Actions
2824  *
2825  * Returns:	0			Success
2826  *              EINVAL			task_set_exception_ports failed
2827  */
2828 static errno_t
exec_handle_exception_port_actions(const struct image_params * imgp,const struct exec_port_actions * actions)2829 exec_handle_exception_port_actions(const struct image_params *imgp,
2830     const struct exec_port_actions *actions)
2831 {
2832 	task_t task = get_threadtask(imgp->ip_new_thread);
2833 
2834 	for (int i = 0; i < actions->exception_port_count; i++) {
2835 		ipc_port_t port = actions->excport_array[i].port;
2836 		_ps_port_action_t *act = actions->excport_array[i].port_action;
2837 		assert(act != NULL);
2838 		kern_return_t kr = task_set_exception_ports(task, act->mask, port,
2839 		    act->behavior, act->flavor);
2840 		if (kr != KERN_SUCCESS) {
2841 			DTRACE_PROC1(spawn__exception__port__failure, mach_port_name_t, act->new_port);
2842 			return EINVAL;
2843 		}
2844 		actions->excport_array[i].port = NULL;
2845 	}
2846 
2847 	return 0;
2848 }
2849 
2850 
2851 /*
2852  * exec_handle_file_actions
2853  *
2854  * Description:	Go through the _posix_file_actions_t contents applying the
2855  *		open, close, and dup2 operations to the open file table for
2856  *		the current process.
2857  *
2858  * Parameters:	struct image_params *	Image parameter block
2859  *
2860  * Returns:	0			Success
2861  *		???
2862  *
2863  * Note:	Actions are applied in the order specified, with the credential
2864  *		of the parent process.  This is done to permit the parent
2865  *		process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
2866  *		the child following operations the child may in fact not be
2867  *		normally permitted to perform.
2868  */
2869 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)2870 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
2871 {
2872 	int error = 0;
2873 	int action;
2874 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2875 	kauth_cred_t p_cred = vfs_context_ucred(imgp->ip_vfs_context);
2876 	_posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
2877 	int ival[2];            /* dummy retval for system calls) */
2878 #if CONFIG_AUDIT
2879 	struct uthread *uthread = current_uthread();
2880 #endif
2881 
2882 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
2883 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2884 
2885 		switch (psfa->psfaa_type) {
2886 		case PSFA_OPEN: {
2887 			/*
2888 			 * Open is different, in that it requires the use of
2889 			 * a path argument, which is normally copied in from
2890 			 * user space; because of this, we have to support an
2891 			 * open from kernel space that passes an address space
2892 			 * context of UIO_SYSSPACE, and casts the address
2893 			 * argument to a user_addr_t.
2894 			 */
2895 			struct vnode_attr *vap;
2896 			struct nameidata *ndp;
2897 			int mode = psfa->psfaa_openargs.psfao_mode;
2898 			int origfd;
2899 			struct {
2900 				struct vnode_attr va;
2901 				struct nameidata nd;
2902 			} *__open_data;
2903 
2904 			__open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
2905 			if (__open_data == NULL) {
2906 				error = ENOMEM;
2907 				break;
2908 			}
2909 
2910 			vap = &__open_data->va;
2911 			ndp = &__open_data->nd;
2912 
2913 			VATTR_INIT(vap);
2914 			/* Mask off all but regular access permissions */
2915 			mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
2916 			VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
2917 
2918 			AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
2919 
2920 			NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2921 			    CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
2922 			    imgp->ip_vfs_context);
2923 
2924 			error = open1(imgp->ip_vfs_context, ndp,
2925 			    psfa->psfaa_openargs.psfao_oflag,
2926 			    vap, NULL, NULL, &origfd, AUTH_OPEN_NOAUTHFD);
2927 
2928 			kfree_type(typeof(*__open_data), __open_data);
2929 
2930 			AUDIT_SUBCALL_EXIT(uthread, error);
2931 
2932 			/*
2933 			 * If there's an error, or we get the right fd by
2934 			 * accident, then drop out here.  This is easier than
2935 			 * reworking all the open code to preallocate fd
2936 			 * slots, and internally taking one as an argument.
2937 			 */
2938 			if (error || origfd == psfa->psfaa_filedes) {
2939 				break;
2940 			}
2941 
2942 			/*
2943 			 * If we didn't fall out from an error, we ended up
2944 			 * with the wrong fd; so now we've got to try to dup2
2945 			 * it to the right one.
2946 			 */
2947 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2948 			error = dup2(p, p_cred, origfd, psfa->psfaa_filedes, ival);
2949 			AUDIT_SUBCALL_EXIT(uthread, error);
2950 			if (error) {
2951 				break;
2952 			}
2953 
2954 			/*
2955 			 * Finally, close the original fd.
2956 			 */
2957 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2958 			error = close_nocancel(p, p_cred, origfd);
2959 			AUDIT_SUBCALL_EXIT(uthread, error);
2960 		}
2961 		break;
2962 
2963 		case PSFA_DUP2: {
2964 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2965 			error = dup2(p, p_cred, psfa->psfaa_filedes,
2966 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2967 			AUDIT_SUBCALL_EXIT(uthread, error);
2968 		}
2969 		break;
2970 
2971 		case PSFA_FILEPORT_DUP2: {
2972 			ipc_port_t port;
2973 			kern_return_t kr;
2974 			int origfd;
2975 
2976 			if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
2977 				error = EINVAL;
2978 				break;
2979 			}
2980 
2981 			kr = ipc_typed_port_copyin_send(get_task_ipcspace(current_task()),
2982 			    psfa->psfaa_fileport, IKOT_FILEPORT, &port);
2983 
2984 			if (kr != KERN_SUCCESS) {
2985 				error = EINVAL;
2986 				break;
2987 			}
2988 
2989 			error = fileport_makefd(p, port, 0, &origfd);
2990 
2991 			if (IPC_PORT_NULL != port) {
2992 				ipc_typed_port_release_send(port, IKOT_FILEPORT);
2993 			}
2994 
2995 			if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
2996 				break;
2997 			}
2998 
2999 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
3000 			error = dup2(p, p_cred, origfd,
3001 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
3002 			AUDIT_SUBCALL_EXIT(uthread, error);
3003 			if (error) {
3004 				break;
3005 			}
3006 
3007 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
3008 			error = close_nocancel(p, p_cred, origfd);
3009 			AUDIT_SUBCALL_EXIT(uthread, error);
3010 		}
3011 		break;
3012 
3013 		case PSFA_CLOSE: {
3014 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
3015 			error = close_nocancel(p, p_cred, psfa->psfaa_filedes);
3016 			AUDIT_SUBCALL_EXIT(uthread, error);
3017 		}
3018 		break;
3019 
3020 		case PSFA_INHERIT: {
3021 			struct fileproc *fp;
3022 
3023 			/*
3024 			 * Check to see if the descriptor exists, and
3025 			 * ensure it's -not- marked as close-on-exec.
3026 			 *
3027 			 * Attempting to "inherit" a guarded fd will
3028 			 * result in a error.
3029 			 */
3030 
3031 			proc_fdlock(p);
3032 			if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
3033 				error = EBADF;
3034 			} else if (fp->fp_guard_attrs) {
3035 				error = fp_guard_exception(p, psfa->psfaa_filedes,
3036 				    fp, kGUARD_EXC_NOCLOEXEC);
3037 			} else {
3038 				fp->fp_flags &= ~FP_CLOEXEC;
3039 				error = 0;
3040 			}
3041 			proc_fdunlock(p);
3042 		}
3043 		break;
3044 
3045 		case PSFA_CHDIR: {
3046 			/*
3047 			 * Chdir is different, in that it requires the use of
3048 			 * a path argument, which is normally copied in from
3049 			 * user space; because of this, we have to support a
3050 			 * chdir from kernel space that passes an address space
3051 			 * context of UIO_SYSSPACE, and casts the address
3052 			 * argument to a user_addr_t.
3053 			 */
3054 			struct nameidata *nd;
3055 			nd = kalloc_type(struct nameidata,
3056 			    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3057 
3058 			AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
3059 			NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
3060 			    CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
3061 			    imgp->ip_vfs_context);
3062 
3063 			error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
3064 			kfree_type(struct nameidata, nd);
3065 			AUDIT_SUBCALL_EXIT(uthread, error);
3066 		}
3067 		break;
3068 
3069 		case PSFA_FCHDIR: {
3070 			AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
3071 			error = fchdir(p, imgp->ip_vfs_context,
3072 			    psfa->psfaa_filedes, false);
3073 			AUDIT_SUBCALL_EXIT(uthread, error);
3074 		}
3075 		break;
3076 
3077 		default:
3078 			error = EINVAL;
3079 			break;
3080 		}
3081 
3082 		/* All file actions failures are considered fatal, per POSIX */
3083 
3084 		if (error) {
3085 			if (PSFA_OPEN == psfa->psfaa_type) {
3086 				DTRACE_PROC1(spawn__open__failure, uintptr_t,
3087 				    psfa->psfaa_openargs.psfao_path);
3088 			} else {
3089 				DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
3090 			}
3091 			break;
3092 		}
3093 	}
3094 
3095 	if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
3096 		return error;
3097 	}
3098 
3099 	/*
3100 	 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
3101 	 * this spawn only) as if "close on exec" is the default
3102 	 * disposition of all pre-existing file descriptors.  In this case,
3103 	 * the list of file descriptors mentioned in the file actions
3104 	 * are the only ones that can be inherited, so mark them now.
3105 	 *
3106 	 * The actual closing part comes later, in fdt_exec().
3107 	 */
3108 	proc_fdlock(p);
3109 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
3110 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3111 		int fd = psfa->psfaa_filedes;
3112 
3113 		switch (psfa->psfaa_type) {
3114 		case PSFA_DUP2:
3115 		case PSFA_FILEPORT_DUP2:
3116 			fd = psfa->psfaa_dup2args.psfad_newfiledes;
3117 			OS_FALLTHROUGH;
3118 		case PSFA_OPEN:
3119 		case PSFA_INHERIT:
3120 			*fdflags(p, fd) |= UF_INHERIT;
3121 			break;
3122 
3123 		case PSFA_CLOSE:
3124 		case PSFA_CHDIR:
3125 		case PSFA_FCHDIR:
3126 			/*
3127 			 * Although PSFA_FCHDIR does have a file descriptor, it is not
3128 			 * *creating* one, thus we do not automatically mark it for
3129 			 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
3130 			 * wishes it to be inherited should use the PSFA_INHERIT action
3131 			 * explicitly.
3132 			 */
3133 			break;
3134 		}
3135 	}
3136 	proc_fdunlock(p);
3137 
3138 	return 0;
3139 }
3140 
3141 #if CONFIG_MACF
3142 /*
3143  * Check that the extension's data is within the bounds of the
3144  * allocation storing all extensions' data
3145  */
3146 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)3147 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
3148     const _ps_mac_policy_extension_t *ext)
3149 {
3150 	uint64_t dataend;
3151 
3152 	if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
3153 		return EOVERFLOW;
3154 	}
3155 	if (__improbable(dataend > px_s->datalen)) {
3156 		return EINVAL;
3157 	}
3158 
3159 	return 0;
3160 }
3161 
3162 /*
3163  * exec_spawnattr_getmacpolicyinfo
3164  */
3165 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)3166 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
3167 {
3168 	const struct ip_px_smpx_s *px_s = macextensions;
3169 	const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
3170 	int i;
3171 
3172 	if (px_s == NULL) {
3173 		return NULL;
3174 	}
3175 
3176 	psmx = px_s->array;
3177 	if (psmx == NULL) {
3178 		return NULL;
3179 	}
3180 
3181 	for (i = 0; i < psmx->psmx_count; i++) {
3182 		const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3183 		if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
3184 			if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
3185 				panic("invalid mac policy extension data");
3186 			}
3187 			if (lenp != NULL) {
3188 				*lenp = (size_t)extension->datalen;
3189 			}
3190 			return (void *)((uintptr_t)px_s->data + extension->dataoff);
3191 		}
3192 	}
3193 
3194 	if (lenp != NULL) {
3195 		*lenp = 0;
3196 	}
3197 	return NULL;
3198 }
3199 
3200 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)3201 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
3202     struct ip_px_smpx_s *pxsp)
3203 {
3204 	_posix_spawn_mac_policy_extensions_t psmx = NULL;
3205 	uint8_t *data = NULL;
3206 	uint64_t datalen = 0;
3207 	uint64_t dataoff = 0;
3208 	int error = 0;
3209 
3210 	bzero(pxsp, sizeof(*pxsp));
3211 
3212 	if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
3213 	    px_args->mac_extensions_size > PAGE_SIZE) {
3214 		error = EINVAL;
3215 		goto bad;
3216 	}
3217 
3218 	psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
3219 	if (psmx == NULL) {
3220 		error = ENOMEM;
3221 		goto bad;
3222 	}
3223 
3224 	error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
3225 	if (error) {
3226 		goto bad;
3227 	}
3228 
3229 	size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
3230 	if (extsize == 0 || extsize > px_args->mac_extensions_size) {
3231 		error = EINVAL;
3232 		goto bad;
3233 	}
3234 
3235 	for (int i = 0; i < psmx->psmx_count; i++) {
3236 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3237 		if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
3238 			error = EINVAL;
3239 			goto bad;
3240 		}
3241 		if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
3242 			error = ENOMEM;
3243 			goto bad;
3244 		}
3245 	}
3246 
3247 	data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
3248 	if (data == NULL) {
3249 		error = ENOMEM;
3250 		goto bad;
3251 	}
3252 
3253 	for (int i = 0; i < psmx->psmx_count; i++) {
3254 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3255 
3256 #if !__LP64__
3257 		if (extension->data > UINT32_MAX) {
3258 			goto bad;
3259 		}
3260 #endif
3261 		error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
3262 		if (error) {
3263 			error = ENOMEM;
3264 			goto bad;
3265 		}
3266 		extension->dataoff = dataoff;
3267 		dataoff += extension->datalen;
3268 	}
3269 
3270 	pxsp->array = psmx;
3271 	pxsp->data = data;
3272 	pxsp->datalen = datalen;
3273 	return 0;
3274 
3275 bad:
3276 	kfree_data(psmx, px_args->mac_extensions_size);
3277 	kfree_data(data, (vm_size_t)datalen);
3278 	return error;
3279 }
3280 #endif /* CONFIG_MACF */
3281 
3282 #if CONFIG_COALITIONS
3283 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])3284 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
3285 {
3286 	for (int c = 0; c < COALITION_NUM_TYPES; c++) {
3287 		if (coal[c]) {
3288 			coalition_remove_active(coal[c]);
3289 			coalition_release(coal[c]);
3290 		}
3291 	}
3292 }
3293 #endif
3294 
3295 #if CONFIG_PERSONAS
3296 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)3297 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
3298 {
3299 	int error = 0;
3300 	struct persona *persona = NULL;
3301 	kauth_cred_t mycred = kauth_cred_get();
3302 
3303 	if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
3304 		return EPERM;
3305 	}
3306 
3307 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3308 		if (px_persona->pspi_ngroups > NGROUPS_MAX) {
3309 			return EINVAL;
3310 		}
3311 	}
3312 
3313 	persona = persona_lookup(px_persona->pspi_id);
3314 	if (!persona) {
3315 		return ESRCH;
3316 	}
3317 
3318 	// non-root process should not be allowed to set persona with uid/gid 0
3319 	if (!kauth_cred_issuser(mycred) &&
3320 	    (px_persona->pspi_uid == 0 || px_persona->pspi_gid == 0)) {
3321 		return EPERM;
3322 	}
3323 
3324 	persona_put(persona);
3325 	return error;
3326 }
3327 
3328 static bool
kauth_cred_model_setpersona(kauth_cred_t model,struct _posix_spawn_persona_info * px_persona)3329 kauth_cred_model_setpersona(
3330 	kauth_cred_t            model,
3331 	struct _posix_spawn_persona_info *px_persona)
3332 {
3333 	bool updated = false;
3334 
3335 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
3336 		updated |= kauth_cred_model_setresuid(model,
3337 		    px_persona->pspi_uid,
3338 		    px_persona->pspi_uid,
3339 		    px_persona->pspi_uid,
3340 		    KAUTH_UID_NONE);
3341 	}
3342 
3343 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
3344 		updated |= kauth_cred_model_setresgid(model,
3345 		    px_persona->pspi_gid,
3346 		    px_persona->pspi_gid,
3347 		    px_persona->pspi_gid);
3348 	}
3349 
3350 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3351 		updated |= kauth_cred_model_setgroups(model,
3352 		    px_persona->pspi_groups,
3353 		    px_persona->pspi_ngroups,
3354 		    px_persona->pspi_gmuid);
3355 	}
3356 
3357 	return updated;
3358 }
3359 
3360 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)3361 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
3362 {
3363 	struct persona *persona = NULL;
3364 
3365 	/*
3366 	 * we want to spawn into the given persona, but we want to override
3367 	 * the kauth with a different UID/GID combo
3368 	 */
3369 	persona = persona_lookup(px_persona->pspi_id);
3370 	if (!persona) {
3371 		return ESRCH;
3372 	}
3373 
3374 	return persona_proc_adopt(p, persona,
3375 	           ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
3376 		return kauth_cred_model_setpersona(model, px_persona);
3377 	});
3378 }
3379 #endif
3380 
3381 #if __arm64__
3382 #if DEVELOPMENT || DEBUG
3383 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
3384     LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
3385 
3386 __startup_func
3387 static void
legacy_footprint_entitlement_mode_init(void)3388 legacy_footprint_entitlement_mode_init(void)
3389 {
3390 	/*
3391 	 * legacy_footprint_entitlement_mode specifies the behavior we want associated
3392 	 * with the entitlement. The supported modes are:
3393 	 *
3394 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3395 	 *	Indicates that we want every process to have the memory accounting
3396 	 *	that is available in iOS 12.0 and beyond.
3397 	 *
3398 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3399 	 *	Indicates that for every process that has the 'legacy footprint entitlement',
3400 	 *      we want to give it the old iOS 11.0 accounting behavior which accounted some
3401 	 *	of the process's memory to the kernel.
3402 	 *
3403 	 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3404 	 *      Indicates that for every process that has the 'legacy footprint entitlement',
3405 	 *	we want it to have a higher memory limit which will help them acclimate to the
3406 	 *	iOS 12.0 (& beyond) accounting behavior that does the right accounting.
3407 	 *      The bonus added to the system-wide task limit to calculate this higher memory limit
3408 	 *      is available in legacy_footprint_bonus_mb.
3409 	 */
3410 
3411 	if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
3412 	    legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
3413 		legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
3414 	}
3415 }
3416 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
3417 #else
3418 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
3419 #endif
3420 
3421 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)3422 proc_legacy_footprint_entitled(proc_t p, task_t task)
3423 {
3424 #pragma unused(p)
3425 	boolean_t legacy_footprint_entitled;
3426 
3427 	switch (legacy_footprint_entitlement_mode) {
3428 	case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3429 		/* the entitlement is ignored */
3430 		break;
3431 	case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3432 		/* the entitlement grants iOS11 legacy accounting */
3433 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3434 		if (legacy_footprint_entitled) {
3435 			task_set_legacy_footprint(task);
3436 		}
3437 		break;
3438 	case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3439 		/* the entitlement grants a footprint limit increase */
3440 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3441 		if (legacy_footprint_entitled) {
3442 			task_set_extra_footprint_limit(task);
3443 		}
3444 		break;
3445 	default:
3446 		break;
3447 	}
3448 }
3449 
3450 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)3451 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
3452 {
3453 #pragma unused(p)
3454 	boolean_t ios13extended_footprint_entitled;
3455 
3456 	/* the entitlement grants a footprint limit increase */
3457 	ios13extended_footprint_entitled = memorystatus_task_has_ios13extended_footprint_limit(proc_task(p));
3458 	if (ios13extended_footprint_entitled) {
3459 		task_set_ios13extended_footprint_limit(task);
3460 	}
3461 }
3462 
3463 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)3464 proc_increased_memory_limit_entitled(proc_t p, task_t task)
3465 {
3466 	if (memorystatus_task_has_increased_debugging_memory_limit_entitlement(task)) {
3467 		memorystatus_act_on_entitled_developer_task_limit(p);
3468 	} else if (memorystatus_task_has_increased_memory_limit_entitlement(task)) {
3469 		memorystatus_act_on_entitled_task_limit(p);
3470 	}
3471 }
3472 
3473 /*
3474  * Check for any of the various entitlements that permit a higher
3475  * task footprint limit or alternate accounting and apply them.
3476  */
3477 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)3478 proc_footprint_entitlement_hacks(proc_t p, task_t task)
3479 {
3480 	proc_legacy_footprint_entitled(p, task);
3481 	proc_ios13extended_footprint_entitled(p, task);
3482 	proc_increased_memory_limit_entitled(p, task);
3483 }
3484 #endif /* __arm64__ */
3485 
3486 /*
3487  * Processes with certain entitlements are granted a jumbo-size VM map.
3488  */
3489 static inline void
proc_apply_jit_and_vm_policies(struct image_params * imgp,proc_t p,task_t task)3490 proc_apply_jit_and_vm_policies(struct image_params *imgp, proc_t p, task_t task)
3491 {
3492 #if CONFIG_MACF
3493 	bool jit_entitled = false;
3494 #endif /* CONFIG_MACF */
3495 	bool needs_jumbo_va = false;
3496 	bool needs_extra_jumbo_va = false;
3497 	struct _posix_spawnattr *psa = imgp->ip_px_sa;
3498 
3499 #if CONFIG_MACF
3500 	jit_entitled = (mac_proc_check_map_anon(p, proc_ucred_unsafe(p),
3501 	    0, 0, 0, MAP_JIT, NULL) == 0);
3502 	needs_jumbo_va = jit_entitled || IOTaskHasEntitlement(task,
3503 	    "com.apple.developer.kernel.extended-virtual-addressing") ||
3504 	    memorystatus_task_has_increased_memory_limit_entitlement(task) ||
3505 	    memorystatus_task_has_increased_debugging_memory_limit_entitlement(task);
3506 #else
3507 #pragma unused(p)
3508 #endif /* CONFIG_MACF */
3509 
3510 
3511 	if (needs_jumbo_va) {
3512 		vm_map_set_jumbo(get_task_map(task));
3513 	}
3514 
3515 	if (psa && psa->psa_max_addr) {
3516 		vm_map_set_max_addr(get_task_map(task), psa->psa_max_addr, false);
3517 	}
3518 
3519 #if CONFIG_MAP_RANGES
3520 	if (task_is_hardened_binary(task) && !proc_is_simulated(p)) {
3521 		/*
3522 		 * This must be done last as it needs to observe
3523 		 * any kind of VA space growth that was requested.
3524 		 * This is used by the secure allocator, so
3525 		 * must be applied to all hardened binaries
3526 		 */
3527 #if XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT
3528 		needs_extra_jumbo_va = IOTaskHasEntitlement(task,
3529 		    "com.apple.kernel.large-file-virtual-addressing");
3530 #endif /* XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT */
3531 		vm_map_range_configure(get_task_map(task), needs_extra_jumbo_va);
3532 	}
3533 #else
3534 #pragma unused(needs_extra_jumbo_va)
3535 #endif /* CONFIG_MAP_RANGES */
3536 
3537 #if CONFIG_MACF
3538 	if (jit_entitled) {
3539 		vm_map_set_jit_entitled(get_task_map(task));
3540 
3541 	}
3542 #endif /* CONFIG_MACF */
3543 
3544 #if XNU_TARGET_OS_OSX
3545 	/* TPRO cannot be enforced on binaries that load 3P plugins on macos - rdar://107420220 */
3546 	const bool task_loads_3P_plugins = imgp->ip_flags & IMGPF_3P_PLUGINS;
3547 #endif /* XNU_TARGET_OS_OSX */
3548 
3549 	if (task_is_hardened_binary(task)
3550 #if XNU_TARGET_OS_OSX
3551 	    && !task_loads_3P_plugins
3552 #endif /* XNU_TARGET_OS_OSX */
3553 	    ) {
3554 		/*
3555 		 * Pre-emptively disable TPRO remapping for
3556 		 * hardened binaries (which do not load 3P plugins)
3557 		 */
3558 		vm_map_set_tpro_enforcement(get_task_map(task));
3559 	}
3560 }
3561 
3562 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)3563 spawn_posix_cred_adopt(proc_t p,
3564     struct _posix_spawn_posix_cred_info *px_pcred_info)
3565 {
3566 	int error = 0;
3567 
3568 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3569 		struct setgid_args args = {
3570 			.gid = px_pcred_info->pspci_gid,
3571 		};
3572 		error = setgid(p, &args, NULL);
3573 		if (error) {
3574 			return error;
3575 		}
3576 	}
3577 
3578 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3579 		error = setgroups_internal(p,
3580 		    px_pcred_info->pspci_ngroups,
3581 		    px_pcred_info->pspci_groups,
3582 		    px_pcred_info->pspci_gmuid);
3583 		if (error) {
3584 			return error;
3585 		}
3586 	}
3587 
3588 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3589 		struct setuid_args args = {
3590 			.uid = px_pcred_info->pspci_uid,
3591 		};
3592 		error = setuid(p, &args, NULL);
3593 		if (error) {
3594 			return error;
3595 		}
3596 	}
3597 	return 0;
3598 }
3599 
3600 /*
3601  * posix_spawn
3602  *
3603  * Parameters:	uap->pid		Pointer to pid return area
3604  *		uap->fname		File name to exec
3605  *		uap->argp		Argument list
3606  *		uap->envp		Environment list
3607  *
3608  * Returns:	0			Success
3609  *		EINVAL			Invalid argument
3610  *		ENOTSUP			Not supported
3611  *		ENOEXEC			Executable file format error
3612  *	exec_activate_image:EINVAL	Invalid argument
3613  *	exec_activate_image:EACCES	Permission denied
3614  *	exec_activate_image:EINTR	Interrupted function
3615  *	exec_activate_image:ENOMEM	Not enough space
3616  *	exec_activate_image:EFAULT	Bad address
3617  *	exec_activate_image:ENAMETOOLONG	Filename too long
3618  *	exec_activate_image:ENOEXEC	Executable file format error
3619  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
3620  *	exec_activate_image:EAUTH	Image decryption failed
3621  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
3622  *	exec_activate_image:???
3623  *	mac_execve_enter:???
3624  *
3625  * TODO:	Expect to need __mac_posix_spawn() at some point...
3626  *		Handle posix_spawnattr_t
3627  *		Handle posix_spawn_file_actions_t
3628  */
3629 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3630 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3631 {
3632 	proc_t p = ap;
3633 	user_addr_t pid = uap->pid;
3634 	int ival[2];            /* dummy retval for setpgid() */
3635 	char *subsystem_root_path = NULL;
3636 	struct image_params *imgp = NULL;
3637 	struct vnode_attr *vap = NULL;
3638 	struct vnode_attr *origvap = NULL;
3639 	struct uthread  *uthread = 0;   /* compiler complains if not set to 0*/
3640 	int error, sig;
3641 	int is_64 = IS_64BIT_PROCESS(p);
3642 	struct vfs_context context;
3643 	struct user__posix_spawn_args_desc px_args = {};
3644 	struct _posix_spawnattr px_sa = {};
3645 	_posix_spawn_file_actions_t px_sfap = NULL;
3646 	_posix_spawn_port_actions_t px_spap = NULL;
3647 	struct __kern_sigaction vec;
3648 	boolean_t spawn_no_exec = FALSE;
3649 	boolean_t proc_transit_set = TRUE;
3650 	boolean_t proc_signal_set = TRUE;
3651 	boolean_t exec_done = FALSE;
3652 	os_reason_t exec_failure_reason = NULL;
3653 
3654 	struct exec_port_actions port_actions = { };
3655 	vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3656 	task_t old_task = current_task();
3657 	task_t new_task = NULL;
3658 	boolean_t should_release_proc_ref = FALSE;
3659 	void *inherit = NULL;
3660 	uint8_t crash_behavior = 0;
3661 	uint64_t crash_behavior_deadline = 0;
3662 #if CONFIG_EXCLAVES
3663 	char *task_conclave_id = NULL;
3664 #endif
3665 #if CONFIG_PERSONAS
3666 	struct _posix_spawn_persona_info *px_persona = NULL;
3667 #endif
3668 	struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3669 	struct {
3670 		struct image_params imgp;
3671 		struct vnode_attr va;
3672 		struct vnode_attr origva;
3673 	} *__spawn_data;
3674 
3675 	/*
3676 	 * Allocate a big chunk for locals instead of using stack since these
3677 	 * structures are pretty big.
3678 	 */
3679 	__spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3680 	if (__spawn_data == NULL) {
3681 		error = ENOMEM;
3682 		goto bad;
3683 	}
3684 	imgp = &__spawn_data->imgp;
3685 	vap = &__spawn_data->va;
3686 	origvap = &__spawn_data->origva;
3687 
3688 	/* Initialize the common data in the image_params structure */
3689 	imgp->ip_user_fname = uap->path;
3690 	imgp->ip_user_argv = uap->argv;
3691 	imgp->ip_user_envv = uap->envp;
3692 	imgp->ip_vattr = vap;
3693 	imgp->ip_origvattr = origvap;
3694 	imgp->ip_vfs_context = &context;
3695 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3696 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3697 	imgp->ip_mac_return = 0;
3698 	imgp->ip_px_persona = NULL;
3699 	imgp->ip_px_pcred_info = NULL;
3700 	imgp->ip_cs_error = OS_REASON_NULL;
3701 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3702 	imgp->ip_subsystem_root_path = NULL;
3703 	imgp->ip_inherited_shared_region_id = NULL;
3704 	imgp->ip_inherited_jop_pid = 0;
3705 	uthread_set_exec_data(current_uthread(), imgp);
3706 
3707 	if (uap->adesc != USER_ADDR_NULL) {
3708 		if (is_64) {
3709 			error = copyin(uap->adesc, &px_args, sizeof(px_args));
3710 		} else {
3711 			struct user32__posix_spawn_args_desc px_args32;
3712 
3713 			error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3714 
3715 			/*
3716 			 * Convert arguments descriptor from external 32 bit
3717 			 * representation to internal 64 bit representation
3718 			 */
3719 			px_args.attr_size = px_args32.attr_size;
3720 			px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3721 			px_args.file_actions_size = px_args32.file_actions_size;
3722 			px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3723 			px_args.port_actions_size = px_args32.port_actions_size;
3724 			px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3725 			px_args.mac_extensions_size = px_args32.mac_extensions_size;
3726 			px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3727 			px_args.coal_info_size = px_args32.coal_info_size;
3728 			px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3729 			px_args.persona_info_size = px_args32.persona_info_size;
3730 			px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3731 			px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3732 			px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3733 			px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3734 			px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3735 			px_args.conclave_id_size = px_args32.conclave_id_size;
3736 			px_args.conclave_id = CAST_USER_ADDR_T(px_args32.conclave_id);
3737 		}
3738 		if (error) {
3739 			goto bad;
3740 		}
3741 
3742 		if (px_args.attr_size != 0) {
3743 			/*
3744 			 * We are not copying the port_actions pointer,
3745 			 * because we already have it from px_args.
3746 			 * This is a bit fragile: <rdar://problem/16427422>
3747 			 */
3748 
3749 			if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3750 				goto bad;
3751 			}
3752 
3753 			imgp->ip_px_sa = &px_sa;
3754 		}
3755 		if (px_args.file_actions_size != 0) {
3756 			/* Limit file_actions to allowed number of open files */
3757 			size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3758 
3759 			if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3760 			    maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3761 				error = EINVAL;
3762 				goto bad;
3763 			}
3764 
3765 			px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3766 			if (px_sfap == NULL) {
3767 				error = ENOMEM;
3768 				goto bad;
3769 			}
3770 			imgp->ip_px_sfa = px_sfap;
3771 
3772 			if ((error = copyin(px_args.file_actions, px_sfap,
3773 			    px_args.file_actions_size)) != 0) {
3774 				goto bad;
3775 			}
3776 
3777 			/* Verify that the action count matches the struct size */
3778 			size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3779 			if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3780 				error = EINVAL;
3781 				goto bad;
3782 			}
3783 		}
3784 		if (px_args.port_actions_size != 0) {
3785 			/* Limit port_actions to one page of data */
3786 			if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3787 			    px_args.port_actions_size > PAGE_SIZE) {
3788 				error = EINVAL;
3789 				goto bad;
3790 			}
3791 
3792 			px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3793 			if (px_spap == NULL) {
3794 				error = ENOMEM;
3795 				goto bad;
3796 			}
3797 			imgp->ip_px_spa = px_spap;
3798 
3799 			if ((error = copyin(px_args.port_actions, px_spap,
3800 			    px_args.port_actions_size)) != 0) {
3801 				goto bad;
3802 			}
3803 
3804 			/* Verify that the action count matches the struct size */
3805 			size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3806 			if (pasize == 0 || pasize != px_args.port_actions_size) {
3807 				error = EINVAL;
3808 				goto bad;
3809 			}
3810 		}
3811 #if CONFIG_PERSONAS
3812 		/* copy in the persona info */
3813 		if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3814 			/* for now, we need the exact same struct in user space */
3815 			if (px_args.persona_info_size != sizeof(*px_persona)) {
3816 				error = ERANGE;
3817 				goto bad;
3818 			}
3819 
3820 			px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3821 			if (px_persona == NULL) {
3822 				error = ENOMEM;
3823 				goto bad;
3824 			}
3825 			imgp->ip_px_persona = px_persona;
3826 
3827 			if ((error = copyin(px_args.persona_info, px_persona,
3828 			    px_args.persona_info_size)) != 0) {
3829 				goto bad;
3830 			}
3831 			if ((error = spawn_validate_persona(px_persona)) != 0) {
3832 				goto bad;
3833 			}
3834 		}
3835 #endif
3836 		/* copy in the posix cred info */
3837 		if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
3838 			/* for now, we need the exact same struct in user space */
3839 			if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
3840 				error = ERANGE;
3841 				goto bad;
3842 			}
3843 
3844 			if (!kauth_cred_issuser(kauth_cred_get())) {
3845 				error = EPERM;
3846 				goto bad;
3847 			}
3848 
3849 			px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
3850 			if (px_pcred_info == NULL) {
3851 				error = ENOMEM;
3852 				goto bad;
3853 			}
3854 			imgp->ip_px_pcred_info = px_pcred_info;
3855 
3856 			if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
3857 			    px_args.posix_cred_info_size)) != 0) {
3858 				goto bad;
3859 			}
3860 
3861 			if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3862 				if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
3863 					error = EINVAL;
3864 					goto bad;
3865 				}
3866 			}
3867 		}
3868 #if CONFIG_MACF
3869 		if (px_args.mac_extensions_size != 0) {
3870 			if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
3871 				goto bad;
3872 			}
3873 		}
3874 #endif /* CONFIG_MACF */
3875 		if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
3876 			/*
3877 			 * If a valid-looking subsystem root has been
3878 			 * specified...
3879 			 */
3880 			if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
3881 				/*
3882 				 * ...AND the parent has the entitlement, copy
3883 				 * the subsystem root path in.
3884 				 */
3885 				subsystem_root_path = zalloc_flags(ZV_NAMEI,
3886 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3887 
3888 				if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
3889 					goto bad;
3890 				}
3891 
3892 				/* Paranoia */
3893 				subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
3894 			}
3895 		}
3896 #if CONFIG_EXCLAVES
3897 
3898 		/*
3899 		 * Calling exclaves_boot_wait() ensures that the conclave name
3900 		 * id will only be set when exclaves are actually
3901 		 * supported/enabled. In practice this will never actually block
3902 		 * as by the time this is called the system will have booted to
3903 		 * EXCLAVECORE if it's supported/enabled.
3904 		 */
3905 		if ((px_args.conclave_id_size > 0) && (px_args.conclave_id_size <= MAXCONCLAVENAME) &&
3906 		    (exclaves_boot_wait(EXCLAVES_BOOT_STAGE_EXCLAVECORE) == KERN_SUCCESS)) {
3907 			if (px_args.conclave_id) {
3908 				if (imgp->ip_px_sa != NULL && (px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3909 					/* Conclave id could be set only for true spawn */
3910 					error = EINVAL;
3911 					goto bad;
3912 				}
3913 				task_conclave_id = kalloc_data(MAXCONCLAVENAME,
3914 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3915 				if ((error = copyin(px_args.conclave_id, task_conclave_id, MAXCONCLAVENAME))) {
3916 					goto bad;
3917 				}
3918 				task_conclave_id[MAXCONCLAVENAME - 1] = 0;
3919 			}
3920 		}
3921 #endif
3922 	}
3923 
3924 	if (IOTaskHasEntitlement(old_task, SPAWN_SET_PANIC_CRASH_BEHAVIOR)) {
3925 		/* Truncate to uint8_t since we only support 2 flags for now */
3926 		crash_behavior = (uint8_t)px_sa.psa_crash_behavior;
3927 		crash_behavior_deadline = px_sa.psa_crash_behavior_deadline;
3928 	}
3929 
3930 	/* set uthread to parent */
3931 	uthread = current_uthread();
3932 
3933 	/*
3934 	 * <rdar://6640530>; this does not result in a behaviour change
3935 	 * relative to Leopard, so there should not be any existing code
3936 	 * which depends on it.
3937 	 */
3938 
3939 	if (imgp->ip_px_sa != NULL) {
3940 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
3941 		if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
3942 			imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
3943 		}
3944 
3945 
3946 #if (DEVELOPMENT || DEBUG)
3947 		if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
3948 			imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
3949 		}
3950 #endif /* (DEVELOPMENT || DEBUG) */
3951 
3952 		if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
3953 			goto bad;
3954 		}
3955 	}
3956 
3957 	/*
3958 	 * If we don't have the extension flag that turns "posix_spawn()"
3959 	 * into "execve() with options", then we will be creating a new
3960 	 * process which does not inherit memory from the parent process,
3961 	 * which is one of the most expensive things about using fork()
3962 	 * and execve().
3963 	 */
3964 	if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3965 		/* Set the new task's coalition, if it is requested.  */
3966 		coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
3967 #if CONFIG_COALITIONS
3968 		int i, ncoals;
3969 		kern_return_t kr = KERN_SUCCESS;
3970 		struct _posix_spawn_coalition_info coal_info;
3971 		int coal_role[COALITION_NUM_TYPES];
3972 
3973 		if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
3974 			goto do_fork1;
3975 		}
3976 
3977 		memset(&coal_info, 0, sizeof(coal_info));
3978 
3979 		if (px_args.coal_info_size > sizeof(coal_info)) {
3980 			px_args.coal_info_size = sizeof(coal_info);
3981 		}
3982 		error = copyin(px_args.coal_info,
3983 		    &coal_info, px_args.coal_info_size);
3984 		if (error != 0) {
3985 			goto bad;
3986 		}
3987 
3988 		ncoals = 0;
3989 		for (i = 0; i < COALITION_NUM_TYPES; i++) {
3990 			uint64_t cid = coal_info.psci_info[i].psci_id;
3991 			if (cid != 0) {
3992 				/*
3993 				 * don't allow tasks which are not in a
3994 				 * privileged coalition to spawn processes
3995 				 * into coalitions other than their own
3996 				 */
3997 				if (!task_is_in_privileged_coalition(proc_task(p), i) &&
3998 				    !IOTaskHasEntitlement(proc_task(p), COALITION_SPAWN_ENTITLEMENT)) {
3999 					coal_dbg("ERROR: %d not in privilegd "
4000 					    "coalition of type %d",
4001 					    proc_getpid(p), i);
4002 					spawn_coalitions_release_all(coal);
4003 					error = EPERM;
4004 					goto bad;
4005 				}
4006 
4007 				coal_dbg("searching for coalition id:%llu", cid);
4008 				/*
4009 				 * take a reference and activation on the
4010 				 * coalition to guard against free-while-spawn
4011 				 * races
4012 				 */
4013 				coal[i] = coalition_find_and_activate_by_id(cid);
4014 				if (coal[i] == COALITION_NULL) {
4015 					coal_dbg("could not find coalition id:%llu "
4016 					    "(perhaps it has been terminated or reaped)", cid);
4017 					/*
4018 					 * release any other coalition's we
4019 					 * may have a reference to
4020 					 */
4021 					spawn_coalitions_release_all(coal);
4022 					error = ESRCH;
4023 					goto bad;
4024 				}
4025 				if (coalition_type(coal[i]) != i) {
4026 					coal_dbg("coalition with id:%lld is not of type:%d"
4027 					    " (it's type:%d)", cid, i, coalition_type(coal[i]));
4028 					spawn_coalitions_release_all(coal);
4029 					error = ESRCH;
4030 					goto bad;
4031 				}
4032 				coal_role[i] = coal_info.psci_info[i].psci_role;
4033 				ncoals++;
4034 			}
4035 		}
4036 		if (ncoals < COALITION_NUM_TYPES) {
4037 			/*
4038 			 * If the user is attempting to spawn into a subset of
4039 			 * the known coalition types, then make sure they have
4040 			 * _at_least_ specified a resource coalition. If not,
4041 			 * the following fork1() call will implicitly force an
4042 			 * inheritance from 'p' and won't actually spawn the
4043 			 * new task into the coalitions the user specified.
4044 			 * (also the call to coalitions_set_roles will panic)
4045 			 */
4046 			if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
4047 				spawn_coalitions_release_all(coal);
4048 				error = EINVAL;
4049 				goto bad;
4050 			}
4051 		}
4052 do_fork1:
4053 #endif /* CONFIG_COALITIONS */
4054 
4055 		/*
4056 		 * note that this will implicitly inherit the
4057 		 * caller's persona (if it exists)
4058 		 */
4059 		error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
4060 		/* returns a thread and task reference */
4061 
4062 		if (error == 0) {
4063 			new_task = get_threadtask(imgp->ip_new_thread);
4064 		}
4065 #if CONFIG_COALITIONS
4066 		/* set the roles of this task within each given coalition */
4067 		if (error == 0) {
4068 			kr = coalitions_set_roles(coal, new_task, coal_role);
4069 			if (kr != KERN_SUCCESS) {
4070 				error = EINVAL;
4071 			}
4072 			if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
4073 			    MACH_COALITION_ADOPT))) {
4074 				for (i = 0; i < COALITION_NUM_TYPES; i++) {
4075 					if (coal[i] != COALITION_NULL) {
4076 						/*
4077 						 * On 32-bit targets, uniqueid
4078 						 * will get truncated to 32 bits
4079 						 */
4080 						KDBG_RELEASE(MACHDBG_CODE(
4081 							    DBG_MACH_COALITION,
4082 							    MACH_COALITION_ADOPT),
4083 						    coalition_id(coal[i]),
4084 						    get_task_uniqueid(new_task));
4085 					}
4086 				}
4087 			}
4088 		}
4089 
4090 		/* drop our references and activations - fork1() now holds them */
4091 		spawn_coalitions_release_all(coal);
4092 #endif /* CONFIG_COALITIONS */
4093 		if (error != 0) {
4094 			goto bad;
4095 		}
4096 		imgp->ip_flags |= IMGPF_SPAWN;  /* spawn w/o exec */
4097 		spawn_no_exec = TRUE;           /* used in later tests */
4098 	} else {
4099 		/* Adjust the user proc count */
4100 		(void)chgproccnt(kauth_getruid(), 1);
4101 		/*
4102 		 * For execve case, create a new proc, task and thread
4103 		 * but don't make the proc visible to userland. After
4104 		 * image activation, the new proc would take place of
4105 		 * the old proc in pid hash and other lists that make
4106 		 * the proc visible to the system.
4107 		 */
4108 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
4109 
4110 		/* task and thread ref returned by cloneproc */
4111 		if (imgp->ip_new_thread == NULL) {
4112 			(void)chgproccnt(kauth_getruid(), -1);
4113 			error = ENOMEM;
4114 			goto bad;
4115 		}
4116 
4117 		new_task = get_threadtask(imgp->ip_new_thread);
4118 		imgp->ip_flags |= IMGPF_EXEC;
4119 	}
4120 
4121 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
4122 
4123 	if (spawn_no_exec) {
4124 		/*
4125 		 * We had to wait until this point before firing the
4126 		 * proc:::create probe, otherwise p would not point to the
4127 		 * child process.
4128 		 */
4129 		DTRACE_PROC1(create, proc_t, p);
4130 	}
4131 	assert(p != NULL);
4132 
4133 	if (subsystem_root_path) {
4134 		/* If a subsystem root was specified, swap it in */
4135 		char * old_subsystem_root_path = p->p_subsystem_root_path;
4136 		p->p_subsystem_root_path = subsystem_root_path;
4137 		subsystem_root_path = old_subsystem_root_path;
4138 	}
4139 
4140 	p->p_crash_behavior = crash_behavior;
4141 	p->p_crash_behavior_deadline = crash_behavior_deadline;
4142 
4143 	p->p_crash_count = px_sa.psa_crash_count;
4144 	p->p_throttle_timeout = px_sa.psa_throttle_timeout;
4145 
4146 	/* We'll need the subsystem root for setting up Apple strings */
4147 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4148 
4149 	context.vc_thread = imgp->ip_new_thread;
4150 	context.vc_ucred = proc_ucred_unsafe(p);  /* in init */
4151 
4152 	/*
4153 	 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
4154 	 * to handle the file_actions.
4155 	 */
4156 
4157 	/* Has spawn file actions? */
4158 	if (imgp->ip_px_sfa != NULL) {
4159 		/*
4160 		 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
4161 		 * is handled in exec_handle_file_actions().
4162 		 */
4163 #if CONFIG_AUDIT
4164 		/*
4165 		 * The file actions auditing can overwrite the upath of
4166 		 * AUE_POSIX_SPAWN audit record.  Save the audit record.
4167 		 */
4168 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4169 		uthread->uu_ar = NULL;
4170 #endif
4171 		error = exec_handle_file_actions(imgp,
4172 		    imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
4173 #if CONFIG_AUDIT
4174 		/* Restore the AUE_POSIX_SPAWN audit record. */
4175 		uthread->uu_ar = save_uu_ar;
4176 #endif
4177 		if (error != 0) {
4178 			goto bad;
4179 		}
4180 	}
4181 
4182 	/* Has spawn port actions? */
4183 	if (imgp->ip_px_spa != NULL) {
4184 #if CONFIG_AUDIT
4185 		/*
4186 		 * Do the same for the port actions as we did for the file
4187 		 * actions.  Save the AUE_POSIX_SPAWN audit record.
4188 		 */
4189 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4190 		uthread->uu_ar = NULL;
4191 #endif
4192 		error = exec_handle_port_actions(imgp, &port_actions);
4193 #if CONFIG_AUDIT
4194 		/* Restore the AUE_POSIX_SPAWN audit record. */
4195 		uthread->uu_ar = save_uu_ar;
4196 #endif
4197 		if (error != 0) {
4198 			goto bad;
4199 		}
4200 	}
4201 
4202 	/* Has spawn attr? */
4203 	if (imgp->ip_px_sa != NULL) {
4204 		/*
4205 		 * Reset UID/GID to parent's RUID/RGID; This works only
4206 		 * because the operation occurs before the call
4207 		 * to exec_handle_sugid() by the image activator called
4208 		 * from exec_activate_image().
4209 		 *
4210 		 * POSIX requires that any setuid/setgid bits on the process
4211 		 * image will take precedence over the spawn attributes
4212 		 * (re)setting them.
4213 		 *
4214 		 * Modifications to p_ucred must be guarded using the
4215 		 * proc's ucred lock. This prevents others from accessing
4216 		 * a garbage credential.
4217 		 */
4218 		if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
4219 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
4220 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model){
4221 				return kauth_cred_model_setuidgid(model,
4222 				kauth_cred_getruid(parent),
4223 				kauth_cred_getrgid(parent));
4224 			});
4225 		}
4226 
4227 		if (imgp->ip_px_pcred_info) {
4228 			if (!spawn_no_exec) {
4229 				error = ENOTSUP;
4230 				goto bad;
4231 			}
4232 
4233 			error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
4234 			if (error != 0) {
4235 				goto bad;
4236 			}
4237 		}
4238 
4239 #if CONFIG_PERSONAS
4240 		if (imgp->ip_px_persona != NULL) {
4241 			if (!spawn_no_exec) {
4242 				error = ENOTSUP;
4243 				goto bad;
4244 			}
4245 
4246 			/*
4247 			 * If we were asked to spawn a process into a new persona,
4248 			 * do the credential switch now (which may override the UID/GID
4249 			 * inherit done just above). It's important to do this switch
4250 			 * before image activation both for reasons stated above, and
4251 			 * to ensure that the new persona has access to the image/file
4252 			 * being executed.
4253 			 */
4254 			error = spawn_persona_adopt(p, imgp->ip_px_persona);
4255 			if (error != 0) {
4256 				goto bad;
4257 			}
4258 		}
4259 #endif /* CONFIG_PERSONAS */
4260 #if !SECURE_KERNEL
4261 		/*
4262 		 * Disable ASLR for the spawned process.
4263 		 *
4264 		 * But only do so if we are not embedded + RELEASE.
4265 		 * While embedded allows for a boot-arg (-disable_aslr)
4266 		 * to deal with this (which itself is only honored on
4267 		 * DEVELOPMENT or DEBUG builds of xnu), it is often
4268 		 * useful or necessary to disable ASLR on a per-process
4269 		 * basis for unit testing and debugging.
4270 		 */
4271 		if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
4272 			OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
4273 		}
4274 #endif /* !SECURE_KERNEL */
4275 
4276 		/* Randomize high bits of ASLR slide */
4277 		if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
4278 			imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
4279 		}
4280 
4281 #if !SECURE_KERNEL
4282 		/*
4283 		 * Forcibly disallow execution from data pages for the spawned process
4284 		 * even if it would otherwise be permitted by the architecture default.
4285 		 */
4286 		if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
4287 			imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
4288 		}
4289 #endif /* !SECURE_KERNEL */
4290 
4291 #if     __has_feature(ptrauth_calls)
4292 		if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
4293 			imgp->ip_flags |= IMGPF_RESLIDE;
4294 		}
4295 #endif /* __has_feature(ptrauth_calls) */
4296 
4297 		if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
4298 		    POSIX_SPAWN_PROC_TYPE_DRIVER) {
4299 			imgp->ip_flags |= IMGPF_DRIVER;
4300 		}
4301 	}
4302 
4303 	/*
4304 	 * Disable ASLR during image activation.  This occurs either if the
4305 	 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
4306 	 * P_DISABLE_ASLR was inherited from the parent process.
4307 	 */
4308 	if (p->p_flag & P_DISABLE_ASLR) {
4309 		imgp->ip_flags |= IMGPF_DISABLE_ASLR;
4310 	}
4311 
4312 	/*
4313 	 * Clear transition flag so we won't hang if exec_activate_image() causes
4314 	 * an automount (and launchd does a proc sysctl to service it).
4315 	 *
4316 	 * <rdar://problem/6848672>, <rdar://problem/5959568>.
4317 	 */
4318 	proc_transend(p, 0);
4319 	proc_transit_set = 0;
4320 
4321 	if (!spawn_no_exec) {
4322 		/*
4323 		 * Clear the signal lock in case of exec, since
4324 		 * image activation uses psignal on child process.
4325 		 */
4326 		proc_signalend(p, 0);
4327 		proc_signal_set = 0;
4328 	}
4329 
4330 #if MAC_SPAWN   /* XXX */
4331 	if (uap->mac_p != USER_ADDR_NULL) {
4332 		error = mac_execve_enter(uap->mac_p, imgp);
4333 		if (error) {
4334 			goto bad;
4335 		}
4336 	}
4337 #endif
4338 	/*
4339 	 * Activate the image.
4340 	 * Warning: If activation failed after point of no return, it returns error
4341 	 * as 0 and pretends the call succeeded.
4342 	 */
4343 	error = exec_activate_image(imgp);
4344 #if defined(HAS_APPLE_PAC)
4345 	const uint8_t disable_user_jop = imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE;
4346 	ml_task_set_jop_pid_from_shared_region(new_task, disable_user_jop);
4347 	ml_task_set_disable_user_jop(new_task, disable_user_jop);
4348 	ml_thread_set_disable_user_jop(imgp->ip_new_thread, disable_user_jop);
4349 	ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4350 #endif
4351 
4352 	/*
4353 	 * If you've come here to add support for some new HW feature or some per-process or per-vmmap
4354 	 * or per-pmap flag that needs to be set before the process runs, or are in general lost, here
4355 	 * is some help. This summary was accurate as of Jul 2022. Use git log as needed. This comment
4356 	 * is here to prevent a recurrence of rdar://96307913
4357 	 *
4358 	 * In posix_spawn, following is what happens:
4359 	 * 1. Lots of prep and checking work
4360 	 * 2. Image activation via exec_activate_image(). The new task will get a new pmap here
4361 	 * 3. More prep work. (YOU ARE HERE)
4362 	 * 4. exec_resettextvp() is called
4363 	 * 5. At this point it is safe to check entitlements and code signatures
4364 	 * 6. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4365 	 *    The new thread is allowed to run in kernel. It cannot yet get to userland
4366 	 * 7. More things done here. This is your chance to affect the task before it runs in
4367 	 *    userspace
4368 	 * 8. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4369 	 *     The new thread is allowed to run in userland
4370 	 */
4371 
4372 	if (error == 0 && !spawn_no_exec) {
4373 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
4374 		/* proc ref returned */
4375 		should_release_proc_ref = TRUE;
4376 	}
4377 
4378 	if (error == 0) {
4379 		/* process completed the exec, but may have failed after point of no return */
4380 		exec_done = TRUE;
4381 	}
4382 
4383 #if CONFIG_EXCLAVES
4384 	if (!error && task_conclave_id != NULL) {
4385 		kern_return_t kr;
4386 		kr = task_add_conclave(new_task, imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
4387 		    task_conclave_id);
4388 		if (kr != KERN_SUCCESS) {
4389 			error = EINVAL;
4390 			goto bad;
4391 		}
4392 	}
4393 #endif
4394 
4395 	if (!error && imgp->ip_px_sa != NULL) {
4396 		thread_t child_thread = imgp->ip_new_thread;
4397 		uthread_t child_uthread = get_bsdthread_info(child_thread);
4398 
4399 		/*
4400 		 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
4401 		 * activation, else when image activation fails (before the point of no
4402 		 * return) would leave the parent process in a modified state.
4403 		 */
4404 		if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
4405 			struct setpgid_args spga;
4406 			spga.pid = proc_getpid(p);
4407 			spga.pgid = px_sa.psa_pgroup;
4408 			/*
4409 			 * Effectively, call setpgid() system call; works
4410 			 * because there are no pointer arguments.
4411 			 */
4412 			if ((error = setpgid(p, &spga, ival)) != 0) {
4413 				goto bad_px_sa;
4414 			}
4415 		}
4416 
4417 		if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
4418 			error = setsid_internal(p);
4419 			if (error != 0) {
4420 				goto bad_px_sa;
4421 			}
4422 		}
4423 
4424 		/*
4425 		 * If we have a spawn attr, and it contains signal related flags,
4426 		 * the we need to process them in the "context" of the new child
4427 		 * process, so we have to process it following image activation,
4428 		 * prior to making the thread runnable in user space.  This is
4429 		 * necessitated by some signal information being per-thread rather
4430 		 * than per-process, and we don't have the new allocation in hand
4431 		 * until after the image is activated.
4432 		 */
4433 
4434 		/*
4435 		 * Mask a list of signals, instead of them being unmasked, if
4436 		 * they were unmasked in the parent; note that some signals
4437 		 * are not maskable.
4438 		 */
4439 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
4440 			child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
4441 		}
4442 		/*
4443 		 * Default a list of signals instead of ignoring them, if
4444 		 * they were ignored in the parent.  Note that we pass
4445 		 * spawn_no_exec to setsigvec() to indicate that we called
4446 		 * fork1() and therefore do not need to call proc_signalstart()
4447 		 * internally.
4448 		 */
4449 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
4450 			vec.sa_handler = SIG_DFL;
4451 			vec.sa_tramp = 0;
4452 			vec.sa_mask = 0;
4453 			vec.sa_flags = 0;
4454 			for (sig = 1; sig < NSIG; sig++) {
4455 				if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
4456 					error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
4457 				}
4458 			}
4459 		}
4460 
4461 		/*
4462 		 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
4463 		 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
4464 		 * limit.
4465 		 *
4466 		 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
4467 		 */
4468 		if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
4469 			/*
4470 			 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
4471 			 * an entitlement to configure the monitor a certain way seems silly, since
4472 			 * whomever is turning it on could just as easily choose not to do so.
4473 			 */
4474 			error = proc_set_task_ruse_cpu(proc_task(p),
4475 			    TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
4476 			    (uint8_t)px_sa.psa_cpumonitor_percent,
4477 			    px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
4478 			    0, TRUE);
4479 		}
4480 
4481 
4482 		if (px_pcred_info &&
4483 		    (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
4484 			/*
4485 			 * setlogin() must happen after setsid()
4486 			 */
4487 			setlogin_internal(p, px_pcred_info->pspci_login);
4488 		}
4489 
4490 bad_px_sa:
4491 		if (error != 0) {
4492 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
4493 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR, 0, 0);
4494 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR);
4495 		}
4496 	}
4497 
4498 bad:
4499 
4500 	if (error == 0) {
4501 		/* reset delay idle sleep status if set */
4502 #if CONFIG_DELAY_IDLE_SLEEP
4503 		if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
4504 			OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
4505 		}
4506 #endif /* CONFIG_DELAY_IDLE_SLEEP */
4507 		/* upon  successful spawn, re/set the proc control state */
4508 		if (imgp->ip_px_sa != NULL) {
4509 			switch (px_sa.psa_pcontrol) {
4510 			case POSIX_SPAWN_PCONTROL_THROTTLE:
4511 				p->p_pcaction = P_PCTHROTTLE;
4512 				break;
4513 			case POSIX_SPAWN_PCONTROL_SUSPEND:
4514 				p->p_pcaction = P_PCSUSP;
4515 				break;
4516 			case POSIX_SPAWN_PCONTROL_KILL:
4517 				p->p_pcaction = P_PCKILL;
4518 				break;
4519 			case POSIX_SPAWN_PCONTROL_NONE:
4520 			default:
4521 				p->p_pcaction = 0;
4522 				break;
4523 			}
4524 			;
4525 		}
4526 		exec_resettextvp(p, imgp);
4527 
4528 		/*
4529 		 * Enable new task IPC access if exec_activate_image() returned an
4530 		 * active task. (Checks active bit in ipc_task_enable() under lock).
4531 		 * Must enable after resettextvp so that task port policies are not evaluated
4532 		 * until the csblob in the textvp is accurately reflected.
4533 		 */
4534 		vm_map_setup(get_task_map(new_task), new_task);
4535 		ipc_task_enable(new_task);
4536 
4537 		/* Set task exception ports now that we can check entitlements */
4538 		if (imgp->ip_px_spa != NULL) {
4539 			error = exec_handle_exception_port_actions(imgp, &port_actions);
4540 		}
4541 
4542 #if CONFIG_MEMORYSTATUS
4543 		/* Set jetsam priority for DriverKit processes */
4544 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4545 			px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
4546 		}
4547 
4548 		/* Has jetsam attributes? */
4549 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
4550 			int32_t memlimit_active = px_sa.psa_memlimit_active;
4551 			int32_t memlimit_inactive = px_sa.psa_memlimit_inactive;
4552 
4553 			memstat_priority_options_t priority_options = MEMSTAT_PRIORITY_OPTIONS_NONE;
4554 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY)) {
4555 				priority_options |= MEMSTAT_PRIORITY_IS_EFFECTIVE;
4556 			}
4557 			memorystatus_set_priority(p, px_sa.psa_priority, 0,
4558 			    priority_options);
4559 
4560 			memlimit_options_t memlimit_options = MEMLIMIT_OPTIONS_NONE;
4561 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL)) {
4562 				memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
4563 			}
4564 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL)) {
4565 				memlimit_options |= MEMLIMIT_INACTIVE_FATAL;
4566 			}
4567 			if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
4568 				/*
4569 				 * With 2-level high-water-mark support,
4570 				 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no longer relevant,
4571 				 * as background limits are described via the inactive limit
4572 				 * slots. However, if the
4573 				 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in, we
4574 				 * attempt to mimic previous behavior by forcing the BG limit
4575 				 * data into the inactive/non-fatal mode and force the active
4576 				 * slots to hold system_wide/fatal mode.
4577 				 */
4578 				memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
4579 				memlimit_options &= ~MEMLIMIT_INACTIVE_FATAL;
4580 				memlimit_active = -1;
4581 			}
4582 			memorystatus_set_memlimits(p, memlimit_active, memlimit_inactive,
4583 			    memlimit_options);
4584 		}
4585 
4586 		/* Has jetsam relaunch behavior? */
4587 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
4588 			/*
4589 			 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
4590 			 * This data would be used by the jetsam subsystem to determine the position and protection
4591 			 * offered to this process on dirty -> clean transitions.
4592 			 */
4593 			int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
4594 			switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
4595 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
4596 				relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
4597 				break;
4598 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
4599 				relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
4600 				break;
4601 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
4602 				relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
4603 				break;
4604 			default:
4605 				break;
4606 			}
4607 			memorystatus_relaunch_flags_update(p, relaunch_flags);
4608 		}
4609 
4610 #endif /* CONFIG_MEMORYSTATUS */
4611 		if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
4612 			task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
4613 		}
4614 
4615 #if CONFIG_PROC_RESOURCE_LIMITS
4616 		if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
4617 			task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
4618 			    (uint32_t)px_sa.psa_port_hard_limit);
4619 		}
4620 
4621 		if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
4622 			proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
4623 			    (int)px_sa.psa_filedesc_hard_limit);
4624 		}
4625 		if (imgp->ip_px_sa != NULL && (px_sa.psa_kqworkloop_soft_limit > 0 || px_sa.psa_kqworkloop_hard_limit > 0)) {
4626 			proc_set_kqworkloop_limits(p, (int)px_sa.psa_kqworkloop_soft_limit,
4627 			    (int)px_sa.psa_kqworkloop_hard_limit);
4628 		}
4629 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
4630 	}
4631 
4632 
4633 	/*
4634 	 * If we successfully called fork1() or cloneproc, we always need
4635 	 * to do this. This is because we come back from that call with
4636 	 * signals blocked in the child, and we have to unblock them, for exec
4637 	 * case they are unblocked before activation, but for true spawn case
4638 	 * we want to wait until after we've performed any spawn actions.
4639 	 * This has to happen before process_signature(), which uses psignal.
4640 	 */
4641 	if (proc_transit_set) {
4642 		proc_transend(p, 0);
4643 	}
4644 
4645 	/*
4646 	 * Drop the signal lock on the child which was taken on our
4647 	 * behalf by forkproc()/cloneproc() to prevent signals being
4648 	 * received by the child in a partially constructed state.
4649 	 */
4650 	if (proc_signal_set) {
4651 		proc_signalend(p, 0);
4652 	}
4653 
4654 	if (error == 0) {
4655 		/*
4656 		 * We need to initialize the bank context behind the protection of
4657 		 * the proc_trans lock to prevent a race with exit. We can't do this during
4658 		 * exec_activate_image because task_bank_init checks entitlements that
4659 		 * aren't loaded until subsequent calls (including exec_resettextvp).
4660 		 */
4661 		error = proc_transstart(p, 0, 0);
4662 
4663 		if (error == 0) {
4664 			task_bank_init(new_task);
4665 			proc_transend(p, 0);
4666 		}
4667 
4668 #if __arm64__
4669 		proc_footprint_entitlement_hacks(p, new_task);
4670 #endif /* __arm64__ */
4671 
4672 #if XNU_TARGET_OS_OSX
4673 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4674 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4675 			vm_map_single_jit(get_task_map(new_task));
4676 		}
4677 #endif /* XNU_TARGET_OS_OSX */
4678 
4679 #if __has_feature(ptrauth_calls)
4680 		task_set_pac_exception_fatal_flag(new_task);
4681 #endif /* __has_feature(ptrauth_calls) */
4682 		task_set_jit_flags(new_task);
4683 	}
4684 
4685 	/* Inherit task role from old task to new task for exec */
4686 	if (error == 0 && !spawn_no_exec) {
4687 		proc_inherit_task_role(new_task, old_task);
4688 	}
4689 
4690 #if CONFIG_ARCADE
4691 	if (error == 0) {
4692 		/*
4693 		 * Check to see if we need to trigger an arcade upcall AST now
4694 		 * that the vnode has been reset on the task.
4695 		 */
4696 		arcade_prepare(new_task, imgp->ip_new_thread);
4697 	}
4698 #endif /* CONFIG_ARCADE */
4699 
4700 	if (error == 0) {
4701 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
4702 	}
4703 
4704 	/* Clear the initial wait on the thread before handling spawn policy */
4705 	if (imgp && imgp->ip_new_thread) {
4706 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4707 	}
4708 
4709 	/*
4710 	 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4711 	 * and bind any portwatch ports to the new task.
4712 	 * This must be done after the exec so that the child's thread is ready,
4713 	 * and after the in transit state has been released, because priority is
4714 	 * dropped here so we need to be prepared for a potentially long preemption interval
4715 	 *
4716 	 * TODO: Consider splitting this up into separate phases
4717 	 */
4718 	if (error == 0 && imgp->ip_px_sa != NULL) {
4719 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4720 
4721 		error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4722 		    psa->psa_darwin_role, &port_actions);
4723 	}
4724 
4725 	/* Transfer the turnstile watchport boost to new task if in exec */
4726 	if (error == 0 && !spawn_no_exec) {
4727 		task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4728 	}
4729 
4730 	if (error == 0 && imgp->ip_px_sa != NULL) {
4731 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4732 
4733 		if (psa->psa_no_smt) {
4734 			task_set_no_smt(new_task);
4735 		}
4736 		if (psa->psa_tecs) {
4737 			task_set_tecs(new_task);
4738 		}
4739 	}
4740 
4741 	if (error == 0 && imgp->ip_px_sa != NULL) {
4742 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4743 
4744 		if (psa->psa_options & PSA_OPTION_DATALESS_IOPOLICY) {
4745 			struct _iopol_param_t iop_param = {
4746 				.iop_scope = IOPOL_SCOPE_PROCESS,
4747 				.iop_iotype = IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES,
4748 				.iop_policy = psa->psa_dataless_iopolicy,
4749 			};
4750 			error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_SET, iop_param.iop_scope,
4751 			    iop_param.iop_policy, &iop_param);
4752 		}
4753 	}
4754 
4755 	if (error == 0) {
4756 		/* Apply the main thread qos */
4757 		thread_t main_thread = imgp->ip_new_thread;
4758 		task_set_main_thread_qos(new_task, main_thread);
4759 	}
4760 
4761 	/*
4762 	 * Release any ports we kept around for binding to the new task
4763 	 * We need to release the rights even if the posix_spawn has failed.
4764 	 */
4765 	if (imgp->ip_px_spa != NULL) {
4766 		exec_port_actions_destroy(&port_actions);
4767 	}
4768 
4769 	/*
4770 	 * We have to delay operations which might throw a signal until after
4771 	 * the signals have been unblocked; however, we want that to happen
4772 	 * after exec_resettextvp() so that the textvp is correct when they
4773 	 * fire.
4774 	 */
4775 	if (error == 0) {
4776 		error = process_signature(p, imgp);
4777 
4778 		/*
4779 		 * Pay for our earlier safety; deliver the delayed signals from
4780 		 * the incomplete spawn process now that it's complete.
4781 		 */
4782 		if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4783 			psignal_vfork(p, proc_task(p), imgp->ip_new_thread, SIGTRAP);
4784 		}
4785 
4786 		if (error == 0 && !spawn_no_exec) {
4787 			extern uint64_t kdp_task_exec_meta_flags(task_t task);
4788 			KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4789 			    proc_getpid(p), kdp_task_exec_meta_flags(proc_task(p)));
4790 		}
4791 	}
4792 
4793 	if (spawn_no_exec) {
4794 		/* flag the 'fork' has occurred */
4795 		proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4796 	}
4797 
4798 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
4799 	if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4800 		proc_knote(p, NOTE_EXEC);
4801 	}
4802 
4803 	if (imgp != NULL) {
4804 		uthread_set_exec_data(current_uthread(), NULL);
4805 		if (imgp->ip_vp) {
4806 			vnode_put(imgp->ip_vp);
4807 		}
4808 		if (imgp->ip_scriptvp) {
4809 			vnode_put(imgp->ip_scriptvp);
4810 		}
4811 		if (imgp->ip_strings) {
4812 			execargs_free(imgp);
4813 		}
4814 		if (imgp->ip_free_map) {
4815 			/* Free the map after dropping iocount on vnode to avoid deadlock */
4816 			vm_map_deallocate(imgp->ip_free_map);
4817 		}
4818 		kfree_data(imgp->ip_px_sfa,
4819 		    px_args.file_actions_size);
4820 		kfree_data(imgp->ip_px_spa,
4821 		    px_args.port_actions_size);
4822 #if CONFIG_PERSONAS
4823 		kfree_data(imgp->ip_px_persona,
4824 		    px_args.persona_info_size);
4825 #endif
4826 		kfree_data(imgp->ip_px_pcred_info,
4827 		    px_args.posix_cred_info_size);
4828 
4829 		if (subsystem_root_path != NULL) {
4830 			zfree(ZV_NAMEI, subsystem_root_path);
4831 		}
4832 #if CONFIG_MACF
4833 		struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
4834 		kfree_data(px_s->array, px_args.mac_extensions_size);
4835 		kfree_data(px_s->data, (vm_size_t)px_s->datalen);
4836 
4837 		if (imgp->ip_execlabelp) {
4838 			mac_cred_label_free(imgp->ip_execlabelp);
4839 			imgp->ip_execlabelp = NULL;
4840 		}
4841 		if (imgp->ip_scriptlabelp) {
4842 			mac_vnode_label_free(imgp->ip_scriptlabelp);
4843 			imgp->ip_scriptlabelp = NULL;
4844 		}
4845 		if (imgp->ip_cs_error != OS_REASON_NULL) {
4846 			os_reason_free(imgp->ip_cs_error);
4847 			imgp->ip_cs_error = OS_REASON_NULL;
4848 		}
4849 		if (imgp->ip_inherited_shared_region_id != NULL) {
4850 			kfree_data(imgp->ip_inherited_shared_region_id,
4851 			    strlen(imgp->ip_inherited_shared_region_id) + 1);
4852 			imgp->ip_inherited_shared_region_id = NULL;
4853 		}
4854 #endif
4855 	}
4856 
4857 #if CONFIG_DTRACE
4858 	if (spawn_no_exec) {
4859 		/*
4860 		 * In the original DTrace reference implementation,
4861 		 * posix_spawn() was a libc routine that just
4862 		 * did vfork(2) then exec(2).  Thus the proc::: probes
4863 		 * are very fork/exec oriented.  The details of this
4864 		 * in-kernel implementation of posix_spawn() is different
4865 		 * (while producing the same process-observable effects)
4866 		 * particularly w.r.t. errors, and which thread/process
4867 		 * is constructing what on behalf of whom.
4868 		 */
4869 		if (error) {
4870 			DTRACE_PROC1(spawn__failure, int, error);
4871 		} else {
4872 			DTRACE_PROC(spawn__success);
4873 			/*
4874 			 * Some DTrace scripts, e.g. newproc.d in
4875 			 * /usr/bin, rely on the the 'exec-success'
4876 			 * probe being fired in the child after the
4877 			 * new process image has been constructed
4878 			 * in order to determine the associated pid.
4879 			 *
4880 			 * So, even though the parent built the image
4881 			 * here, for compatibility, mark the new thread
4882 			 * so 'exec-success' fires on it as it leaves
4883 			 * the kernel.
4884 			 */
4885 			dtrace_thread_didexec(imgp->ip_new_thread);
4886 		}
4887 	} else {
4888 		if (error) {
4889 			DTRACE_PROC1(exec__failure, int, error);
4890 		} else {
4891 			dtrace_thread_didexec(imgp->ip_new_thread);
4892 		}
4893 	}
4894 
4895 	if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4896 		(*dtrace_proc_waitfor_hook)(p);
4897 	}
4898 #endif
4899 
4900 #if CONFIG_AUDIT
4901 	if (!error && AUDIT_ENABLED() && p) {
4902 		/* Add the CDHash of the new process to the audit record */
4903 		uint8_t *cdhash = cs_get_cdhash(p);
4904 		if (cdhash) {
4905 			AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4906 		}
4907 	}
4908 #endif
4909 
4910 	/* terminate the new task if exec failed  */
4911 	if (new_task != NULL && task_is_exec_copy(new_task)) {
4912 		task_terminate_internal(new_task);
4913 	}
4914 
4915 	if (exec_failure_reason && !spawn_no_exec) {
4916 		psignal_with_reason(p, SIGKILL, exec_failure_reason);
4917 		exec_failure_reason = NULL;
4918 	}
4919 
4920 	/* Return to both the parent and the child? */
4921 	if (imgp != NULL && spawn_no_exec) {
4922 		/*
4923 		 * If the parent wants the pid, copy it out
4924 		 */
4925 		if (error == 0 && pid != USER_ADDR_NULL) {
4926 			_Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
4927 			bool aligned = (pid & 3) == 0;
4928 			if (aligned) {
4929 				(void)copyout_atomic32(proc_getpid(p), pid);
4930 			} else {
4931 				(void)suword(pid, proc_getpid(p));
4932 			}
4933 		}
4934 		retval[0] = error;
4935 
4936 		/*
4937 		 * If we had an error, perform an internal reap ; this is
4938 		 * entirely safe, as we have a real process backing us.
4939 		 */
4940 		if (error) {
4941 			proc_list_lock();
4942 			p->p_listflag |= P_LIST_DEADPARENT;
4943 			proc_list_unlock();
4944 			proc_lock(p);
4945 			/* make sure no one else has killed it off... */
4946 			if (p->p_stat != SZOMB && p->exit_thread == NULL) {
4947 				p->exit_thread = current_thread();
4948 				p->p_posix_spawn_failed = true;
4949 				proc_unlock(p);
4950 				exit1(p, 1, (int *)NULL);
4951 			} else {
4952 				/* someone is doing it for us; just skip it */
4953 				proc_unlock(p);
4954 			}
4955 		}
4956 	}
4957 
4958 	/*
4959 	 * Do not terminate the current task, if proc_exec_switch_task did not
4960 	 * switch the tasks, terminating the current task without the switch would
4961 	 * result in loosing the SIGKILL status.
4962 	 */
4963 	if (task_did_exec(old_task)) {
4964 		/* Terminate the current task, since exec will start in new task */
4965 		task_terminate_internal(old_task);
4966 	}
4967 
4968 	/* Release the thread ref returned by cloneproc/fork1 */
4969 	if (imgp != NULL && imgp->ip_new_thread) {
4970 		/* clear the exec complete flag if there is an error before point of no-return */
4971 		uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
4972 		if (!spawn_no_exec && !exec_done && error != 0) {
4973 			clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
4974 		}
4975 		/* wake up the new thread */
4976 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
4977 		thread_deallocate(imgp->ip_new_thread);
4978 		imgp->ip_new_thread = NULL;
4979 	}
4980 
4981 	/* Release the ref returned by cloneproc/fork1 */
4982 	if (new_task) {
4983 		task_deallocate(new_task);
4984 		new_task = NULL;
4985 	}
4986 
4987 	if (should_release_proc_ref) {
4988 		proc_rele(p);
4989 	}
4990 
4991 	kfree_type(typeof(*__spawn_data), __spawn_data);
4992 
4993 	if (inherit != NULL) {
4994 		ipc_importance_release(inherit);
4995 	}
4996 
4997 #if CONFIG_EXCLAVES
4998 	if (task_conclave_id != NULL) {
4999 		kfree_data(task_conclave_id, MAXCONCLAVENAME);
5000 	}
5001 #endif
5002 
5003 	assert(spawn_no_exec || exec_failure_reason == NULL);
5004 	return error;
5005 }
5006 
5007 /*
5008  * proc_exec_switch_task
5009  *
5010  * Parameters:  old_proc		proc before exec
5011  *		new_proc		proc after exec
5012  *		old_task		task before exec
5013  *		new_task		task after exec
5014  *		imgp			image params
5015  *		inherit			resulting importance linkage
5016  *
5017  * Returns: proc.
5018  *
5019  * Note: The function will switch proc in pid hash from old proc to new proc.
5020  * The switch needs to happen after draining all proc refs and inside
5021  * a proc list lock. In the case of failure to switch the proc, which
5022  * might happen if the process received a SIGKILL or jetsam killed it,
5023  * it will make sure that the new tasks terminates. User proc ref returned
5024  * to caller.
5025  *
5026  * This function is called after point of no return, in the case
5027  * failure to switch, it will terminate the new task and swallow the
5028  * error and let the terminated process complete exec and die.
5029  */
5030 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)5031 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)
5032 {
5033 	boolean_t task_active;
5034 	boolean_t proc_active;
5035 	boolean_t thread_active;
5036 	boolean_t reparent_traced_child = FALSE;
5037 	thread_t old_thread = current_thread();
5038 	thread_t new_thread = imgp->ip_new_thread;
5039 
5040 	thread_set_exec_promotion(old_thread);
5041 	old_proc = proc_refdrain_will_exec(old_proc);
5042 
5043 	new_proc = proc_refdrain_will_exec(new_proc);
5044 	/* extra proc ref returned to the caller */
5045 
5046 	assert(get_threadtask(new_thread) == new_task);
5047 	task_active = task_is_active(new_task);
5048 	proc_active = !(old_proc->p_lflag & P_LEXIT);
5049 
5050 	/* Check if the current thread is not aborted due to SIGKILL */
5051 	thread_active = thread_is_active(old_thread);
5052 
5053 	/*
5054 	 * Do not switch the proc if the new task or proc is already terminated
5055 	 * as a result of error in exec past point of no return
5056 	 */
5057 	if (proc_active && task_active && thread_active) {
5058 		uthread_t new_uthread = get_bsdthread_info(new_thread);
5059 		uthread_t old_uthread = current_uthread();
5060 
5061 		/* Clear dispatchqueue and workloop ast offset */
5062 		new_proc->p_dispatchqueue_offset = 0;
5063 		new_proc->p_dispatchqueue_serialno_offset = 0;
5064 		new_proc->p_dispatchqueue_label_offset = 0;
5065 		new_proc->p_return_to_kernel_offset = 0;
5066 		new_proc->p_pthread_wq_quantum_offset = 0;
5067 
5068 		/* If old_proc is session leader, change the leader to new proc */
5069 		session_replace_leader(old_proc, new_proc);
5070 
5071 		proc_lock(old_proc);
5072 
5073 		/* Copy the signal state, dtrace state and set bsd ast on new thread */
5074 		act_set_astbsd(new_thread);
5075 		new_uthread->uu_siglist |= old_uthread->uu_siglist;
5076 		new_uthread->uu_siglist |= old_proc->p_siglist;
5077 		new_uthread->uu_sigwait = old_uthread->uu_sigwait;
5078 		new_uthread->uu_sigmask = old_uthread->uu_sigmask;
5079 		new_uthread->uu_oldmask = old_uthread->uu_oldmask;
5080 		new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
5081 #if CONFIG_DTRACE
5082 		new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
5083 		new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
5084 		new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
5085 		assert(new_uthread->t_dtrace_scratch == NULL);
5086 		new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
5087 
5088 		old_uthread->t_dtrace_sig = 0;
5089 		old_uthread->t_dtrace_stop = 0;
5090 		old_uthread->t_dtrace_resumepid = 0;
5091 		old_uthread->t_dtrace_scratch = NULL;
5092 #endif
5093 
5094 #if CONFIG_PROC_UDATA_STORAGE
5095 		new_proc->p_user_data = old_proc->p_user_data;
5096 #endif /* CONFIG_PROC_UDATA_STORAGE */
5097 
5098 		/* Copy the resource accounting info */
5099 		thread_copy_resource_info(new_thread, current_thread());
5100 
5101 		/* Clear the exit reason and signal state on old thread */
5102 		old_uthread->uu_exit_reason = NULL;
5103 		old_uthread->uu_siglist = 0;
5104 
5105 		task_set_did_exec_flag(old_task);
5106 		task_clear_exec_copy_flag(new_task);
5107 
5108 		task_copy_fields_for_exec(new_task, old_task);
5109 
5110 		/*
5111 		 * Need to transfer pending watch port boosts to the new task
5112 		 * while still making sure that the old task remains in the
5113 		 * importance linkage. Create an importance linkage from old task
5114 		 * to new task, then switch the task importance base of old task
5115 		 * and new task. After the switch the port watch boost will be
5116 		 * boosting the new task and new task will be donating importance
5117 		 * to old task.
5118 		 */
5119 		*inherit = ipc_importance_exec_switch_task(old_task, new_task);
5120 
5121 		/* Transfer parent's ptrace state to child */
5122 		new_proc->p_lflag &= ~(P_LTRACED | P_LSIGEXC | P_LNOATTACH);
5123 		new_proc->p_lflag |= (old_proc->p_lflag & (P_LTRACED | P_LSIGEXC | P_LNOATTACH));
5124 		new_proc->p_oppid = old_proc->p_oppid;
5125 
5126 		if (old_proc->p_pptr != new_proc->p_pptr) {
5127 			reparent_traced_child = TRUE;
5128 			new_proc->p_lflag |= P_LTRACE_WAIT;
5129 		}
5130 
5131 		proc_unlock(old_proc);
5132 
5133 		/* Update the list of proc knotes */
5134 		proc_transfer_knotes(old_proc, new_proc);
5135 
5136 		/* Update the proc interval timers */
5137 		proc_inherit_itimers(old_proc, new_proc);
5138 
5139 		proc_list_lock();
5140 
5141 		/* Insert the new proc in child list of parent proc */
5142 		p_reparentallchildren(old_proc, new_proc);
5143 
5144 		/* Switch proc in pid hash */
5145 		phash_replace_locked(old_proc, new_proc);
5146 
5147 		/* Transfer the shadow flag to old proc */
5148 		os_atomic_andnot(&new_proc->p_refcount, P_REF_SHADOW, relaxed);
5149 		os_atomic_or(&old_proc->p_refcount, P_REF_SHADOW, relaxed);
5150 
5151 		/* Change init proc if launchd exec */
5152 		if (old_proc == initproc) {
5153 			/* Take the ref on new proc after proc_refwake_did_exec */
5154 			initproc = new_proc;
5155 			/* Drop the proc ref on old proc */
5156 			proc_rele(old_proc);
5157 		}
5158 
5159 		proc_list_unlock();
5160 #if CONFIG_EXCLAVES
5161 		if (task_inherit_conclave(old_task, new_task, imgp->ip_vp,
5162 		    (int64_t)imgp->ip_arch_offset) != KERN_SUCCESS) {
5163 			task_terminate_internal(new_task);
5164 		}
5165 #endif
5166 	} else {
5167 		task_terminate_internal(new_task);
5168 	}
5169 
5170 	proc_refwake_did_exec(new_proc);
5171 	proc_refwake_did_exec(old_proc);
5172 
5173 	/* Take a ref on initproc if it changed */
5174 	if (new_proc == initproc) {
5175 		initproc = proc_ref(new_proc, false);
5176 		assert(initproc != PROC_NULL);
5177 	}
5178 
5179 	thread_clear_exec_promotion(old_thread);
5180 	proc_rele(old_proc);
5181 
5182 	if (reparent_traced_child) {
5183 		proc_t pp = proc_parent(old_proc);
5184 		assert(pp != PROC_NULL);
5185 
5186 		proc_reparentlocked(new_proc, pp, 1, 0);
5187 		proc_rele(pp);
5188 
5189 		proc_lock(new_proc);
5190 		new_proc->p_lflag &= ~P_LTRACE_WAIT;
5191 		proc_unlock(new_proc);
5192 	}
5193 
5194 	return new_proc;
5195 }
5196 
5197 /*
5198  * execve
5199  *
5200  * Parameters:	uap->fname		File name to exec
5201  *		uap->argp		Argument list
5202  *		uap->envp		Environment list
5203  *
5204  * Returns:	0			Success
5205  *	__mac_execve:EINVAL		Invalid argument
5206  *	__mac_execve:ENOTSUP		Invalid argument
5207  *	__mac_execve:EACCES		Permission denied
5208  *	__mac_execve:EINTR		Interrupted function
5209  *	__mac_execve:ENOMEM		Not enough space
5210  *	__mac_execve:EFAULT		Bad address
5211  *	__mac_execve:ENAMETOOLONG	Filename too long
5212  *	__mac_execve:ENOEXEC		Executable file format error
5213  *	__mac_execve:ETXTBSY		Text file busy [misuse of error code]
5214  *	__mac_execve:???
5215  *
5216  * TODO:	Dynamic linker header address on stack is copied via suword()
5217  */
5218 /* ARGSUSED */
5219 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)5220 execve(proc_t p, struct execve_args *uap, int32_t *retval)
5221 {
5222 	struct __mac_execve_args muap;
5223 	int err;
5224 
5225 	memoryshot(DBG_VM_EXECVE, DBG_FUNC_NONE);
5226 
5227 	muap.fname = uap->fname;
5228 	muap.argp = uap->argp;
5229 	muap.envp = uap->envp;
5230 	muap.mac_p = USER_ADDR_NULL;
5231 	err = __mac_execve(p, &muap, retval);
5232 
5233 	return err;
5234 }
5235 
5236 /*
5237  * __mac_execve
5238  *
5239  * Parameters:	uap->fname		File name to exec
5240  *		uap->argp		Argument list
5241  *		uap->envp		Environment list
5242  *		uap->mac_p		MAC label supplied by caller
5243  *
5244  * Returns:	0			Success
5245  *		EINVAL			Invalid argument
5246  *		ENOTSUP			Not supported
5247  *		ENOEXEC			Executable file format error
5248  *	exec_activate_image:EINVAL	Invalid argument
5249  *	exec_activate_image:EACCES	Permission denied
5250  *	exec_activate_image:EINTR	Interrupted function
5251  *	exec_activate_image:ENOMEM	Not enough space
5252  *	exec_activate_image:EFAULT	Bad address
5253  *	exec_activate_image:ENAMETOOLONG	Filename too long
5254  *	exec_activate_image:ENOEXEC	Executable file format error
5255  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
5256  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
5257  *	exec_activate_image:???
5258  *	mac_execve_enter:???
5259  *
5260  * TODO:	Dynamic linker header address on stack is copied via suword()
5261  */
5262 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)5263 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
5264 {
5265 	struct image_params *imgp = NULL;
5266 	struct vnode_attr *vap = NULL;
5267 	struct vnode_attr *origvap = NULL;
5268 	int error;
5269 	int is_64 = IS_64BIT_PROCESS(p);
5270 	struct vfs_context context;
5271 	struct uthread  *uthread = NULL;
5272 	task_t old_task = current_task();
5273 	task_t new_task = NULL;
5274 	boolean_t should_release_proc_ref = FALSE;
5275 	boolean_t exec_done = FALSE;
5276 	void *inherit = NULL;
5277 	struct {
5278 		struct image_params imgp;
5279 		struct vnode_attr va;
5280 		struct vnode_attr origva;
5281 	} *__execve_data;
5282 
5283 	/* Allocate a big chunk for locals instead of using stack since these
5284 	 * structures are pretty big.
5285 	 */
5286 	__execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
5287 	if (__execve_data == NULL) {
5288 		error = ENOMEM;
5289 		goto exit_with_error;
5290 	}
5291 	imgp = &__execve_data->imgp;
5292 	vap = &__execve_data->va;
5293 	origvap = &__execve_data->origva;
5294 
5295 	/* Initialize the common data in the image_params structure */
5296 	imgp->ip_user_fname = uap->fname;
5297 	imgp->ip_user_argv = uap->argp;
5298 	imgp->ip_user_envv = uap->envp;
5299 	imgp->ip_vattr = vap;
5300 	imgp->ip_origvattr = origvap;
5301 	imgp->ip_vfs_context = &context;
5302 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
5303 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
5304 	imgp->ip_mac_return = 0;
5305 	imgp->ip_cs_error = OS_REASON_NULL;
5306 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
5307 	imgp->ip_subsystem_root_path = NULL;
5308 	uthread_set_exec_data(current_uthread(), imgp);
5309 
5310 #if CONFIG_MACF
5311 	if (uap->mac_p != USER_ADDR_NULL) {
5312 		error = mac_execve_enter(uap->mac_p, imgp);
5313 		if (error) {
5314 			goto exit_with_error;
5315 		}
5316 	}
5317 #endif
5318 	uthread = current_uthread();
5319 	{
5320 		imgp->ip_flags |= IMGPF_EXEC;
5321 
5322 		/* Adjust the user proc count */
5323 		(void)chgproccnt(kauth_getruid(), 1);
5324 		/*
5325 		 * For execve case, create a new proc, task and thread
5326 		 * but don't make the proc visible to userland. After
5327 		 * image activation, the new proc would take place of
5328 		 * the old proc in pid hash and other lists that make
5329 		 * the proc visible to the system.
5330 		 */
5331 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
5332 		/* task and thread ref returned by cloneproc */
5333 		if (imgp->ip_new_thread == NULL) {
5334 			(void)chgproccnt(kauth_getruid(), -1);
5335 			error = ENOMEM;
5336 			goto exit_with_error;
5337 		}
5338 
5339 		new_task = get_threadtask(imgp->ip_new_thread);
5340 	}
5341 
5342 
5343 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
5344 
5345 	context.vc_thread = imgp->ip_new_thread;
5346 	context.vc_ucred = kauth_cred_proc_ref(p);      /* XXX must NOT be kauth_cred_get() */
5347 
5348 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
5349 
5350 	proc_transend(p, 0);
5351 	proc_signalend(p, 0);
5352 
5353 	/*
5354 	 * Activate the image.
5355 	 * Warning: If activation failed after point of no return, it returns error
5356 	 * as 0 and pretends the call succeeded.
5357 	 */
5358 	error = exec_activate_image(imgp);
5359 	/* thread and task ref returned for vfexec case */
5360 
5361 	if (imgp->ip_new_thread != NULL) {
5362 		/*
5363 		 * task reference might be returned by exec_activate_image
5364 		 * for vfexec.
5365 		 */
5366 		new_task = get_threadtask(imgp->ip_new_thread);
5367 #if defined(HAS_APPLE_PAC)
5368 		ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5369 		ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5370 #endif
5371 	}
5372 
5373 	if (!error) {
5374 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
5375 		/* proc ref returned */
5376 		should_release_proc_ref = TRUE;
5377 	}
5378 
5379 	kauth_cred_unref(&context.vc_ucred);
5380 
5381 	if (!error) {
5382 		exec_done = TRUE;
5383 		assert(imgp->ip_new_thread != NULL);
5384 
5385 		exec_resettextvp(p, imgp);
5386 		/*
5387 		 * Enable new task IPC access if exec_activate_image() returned an
5388 		 * active task. (Checks active bit in ipc_task_enable() under lock).
5389 		 * Must enable after resettextvp so that task port policies are not evaluated
5390 		 * until the csblob in the textvp is accurately reflected.
5391 		 */
5392 		vm_map_setup(get_task_map(new_task), new_task);
5393 		ipc_task_enable(new_task);
5394 		error = process_signature(p, imgp);
5395 	}
5396 
5397 #if defined(HAS_APPLE_PAC)
5398 	if (imgp->ip_new_thread && !error) {
5399 		ml_task_set_jop_pid_from_shared_region(new_task, imgp->ip_flags & IMGPF_NOJOP);
5400 		ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
5401 	}
5402 #endif /* defined(HAS_APPLE_PAC) */
5403 
5404 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
5405 	if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
5406 		proc_knote(p, NOTE_EXEC);
5407 	}
5408 
5409 	if (imgp->ip_vp != NULLVP) {
5410 		vnode_put(imgp->ip_vp);
5411 	}
5412 	if (imgp->ip_scriptvp != NULLVP) {
5413 		vnode_put(imgp->ip_scriptvp);
5414 	}
5415 	if (imgp->ip_free_map) {
5416 		/* Free the map after dropping iocount on vnode to avoid deadlock */
5417 		vm_map_deallocate(imgp->ip_free_map);
5418 	}
5419 	if (imgp->ip_strings) {
5420 		execargs_free(imgp);
5421 	}
5422 #if CONFIG_MACF
5423 	if (imgp->ip_execlabelp) {
5424 		mac_cred_label_free(imgp->ip_execlabelp);
5425 		imgp->ip_execlabelp = NULL;
5426 	}
5427 	if (imgp->ip_scriptlabelp) {
5428 		mac_vnode_label_free(imgp->ip_scriptlabelp);
5429 		imgp->ip_scriptlabelp = NULL;
5430 	}
5431 #endif
5432 	if (imgp->ip_cs_error != OS_REASON_NULL) {
5433 		os_reason_free(imgp->ip_cs_error);
5434 		imgp->ip_cs_error = OS_REASON_NULL;
5435 	}
5436 
5437 	if (!error) {
5438 		/*
5439 		 * We need to initialize the bank context behind the protection of
5440 		 * the proc_trans lock to prevent a race with exit. We can't do this during
5441 		 * exec_activate_image because task_bank_init checks entitlements that
5442 		 * aren't loaded until subsequent calls (including exec_resettextvp).
5443 		 */
5444 		error = proc_transstart(p, 0, 0);
5445 	}
5446 
5447 	if (!error) {
5448 		task_bank_init(new_task);
5449 		proc_transend(p, 0);
5450 
5451 		// Don't inherit crash behavior across exec, but preserve crash behavior from bootargs
5452 		p->p_crash_behavior = 0;
5453 		p->p_crash_behavior_deadline = 0;
5454 #if (DEVELOPMENT || DEBUG)
5455 		set_crash_behavior_from_bootarg(p);
5456 #endif
5457 
5458 #if __arm64__
5459 		proc_footprint_entitlement_hacks(p, new_task);
5460 #endif /* __arm64__ */
5461 
5462 #if XNU_TARGET_OS_OSX
5463 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
5464 			vm_map_single_jit(get_task_map(new_task));
5465 		}
5466 #endif /* XNU_TARGET_OS_OSX */
5467 
5468 		/* Sever any extant thread affinity */
5469 		thread_affinity_exec(current_thread());
5470 
5471 		/* Inherit task role from old task to new task for exec */
5472 		proc_inherit_task_role(new_task, old_task);
5473 
5474 		thread_t main_thread = imgp->ip_new_thread;
5475 
5476 		task_set_main_thread_qos(new_task, main_thread);
5477 
5478 #if __has_feature(ptrauth_calls)
5479 		task_set_pac_exception_fatal_flag(new_task);
5480 #endif /* __has_feature(ptrauth_calls) */
5481 		task_set_jit_flags(new_task);
5482 
5483 #if CONFIG_ARCADE
5484 		/*
5485 		 * Check to see if we need to trigger an arcade upcall AST now
5486 		 * that the vnode has been reset on the task.
5487 		 */
5488 		arcade_prepare(new_task, imgp->ip_new_thread);
5489 #endif /* CONFIG_ARCADE */
5490 
5491 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
5492 
5493 		if (vm_darkwake_mode == TRUE) {
5494 			/*
5495 			 * This process is being launched when the system
5496 			 * is in darkwake. So mark it specially. This will
5497 			 * cause all its pages to be entered in the background Q.
5498 			 */
5499 			task_set_darkwake_mode(new_task, vm_darkwake_mode);
5500 		}
5501 
5502 #if CONFIG_DTRACE
5503 		dtrace_thread_didexec(imgp->ip_new_thread);
5504 
5505 		if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5506 			(*dtrace_proc_waitfor_hook)(p);
5507 		}
5508 #endif
5509 
5510 #if CONFIG_AUDIT
5511 		if (!error && AUDIT_ENABLED() && p) {
5512 			/* Add the CDHash of the new process to the audit record */
5513 			uint8_t *cdhash = cs_get_cdhash(p);
5514 			if (cdhash) {
5515 				AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5516 			}
5517 		}
5518 #endif
5519 	} else {
5520 		DTRACE_PROC1(exec__failure, int, error);
5521 	}
5522 
5523 exit_with_error:
5524 
5525 	/* terminate the new task it if exec failed  */
5526 	if (new_task != NULL && task_is_exec_copy(new_task)) {
5527 		task_terminate_internal(new_task);
5528 	}
5529 
5530 	if (imgp != NULL) {
5531 		/* Clear the initial wait on the thread transferring watchports */
5532 		if (imgp->ip_new_thread) {
5533 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
5534 		}
5535 
5536 		/* Transfer the watchport boost to new task */
5537 		if (!error) {
5538 			task_transfer_turnstile_watchports(old_task,
5539 			    new_task, imgp->ip_new_thread);
5540 		}
5541 		/*
5542 		 * Do not terminate the current task, if proc_exec_switch_task did not
5543 		 * switch the tasks, terminating the current task without the switch would
5544 		 * result in loosing the SIGKILL status.
5545 		 */
5546 		if (task_did_exec(old_task)) {
5547 			/* Terminate the current task, since exec will start in new task */
5548 			task_terminate_internal(old_task);
5549 		}
5550 
5551 		/* Release the thread ref returned by cloneproc */
5552 		if (imgp->ip_new_thread) {
5553 			/* clear the exec complete flag if there is an error before point of no-return */
5554 			uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5555 			if (!exec_done && error != 0) {
5556 				clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5557 			}
5558 			/* wake up the new exec thread */
5559 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5560 			thread_deallocate(imgp->ip_new_thread);
5561 			imgp->ip_new_thread = NULL;
5562 		}
5563 	}
5564 
5565 	/* Release the ref returned by fork_create_child */
5566 	if (new_task) {
5567 		task_deallocate(new_task);
5568 		new_task = NULL;
5569 	}
5570 
5571 	if (should_release_proc_ref) {
5572 		proc_rele(p);
5573 	}
5574 
5575 	uthread_set_exec_data(current_uthread(), NULL);
5576 	kfree_type(typeof(*__execve_data), __execve_data);
5577 
5578 	if (inherit != NULL) {
5579 		ipc_importance_release(inherit);
5580 	}
5581 
5582 	return error;
5583 }
5584 
5585 
5586 /*
5587  * copyinptr
5588  *
5589  * Description:	Copy a pointer in from user space to a user_addr_t in kernel
5590  *		space, based on 32/64 bitness of the user space
5591  *
5592  * Parameters:	froma			User space address
5593  *		toptr			Address of kernel space user_addr_t
5594  *		ptr_size		4/8, based on 'froma' address space
5595  *
5596  * Returns:	0			Success
5597  *		EFAULT			Bad 'froma'
5598  *
5599  * Implicit returns:
5600  *		*ptr_size		Modified
5601  */
5602 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)5603 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
5604 {
5605 	int error;
5606 
5607 	if (ptr_size == 4) {
5608 		/* 64 bit value containing 32 bit address */
5609 		unsigned int i = 0;
5610 
5611 		error = copyin(froma, &i, 4);
5612 		*toptr = CAST_USER_ADDR_T(i);   /* SAFE */
5613 	} else {
5614 		error = copyin(froma, toptr, 8);
5615 	}
5616 	return error;
5617 }
5618 
5619 
5620 /*
5621  * copyoutptr
5622  *
5623  * Description:	Copy a pointer out from a user_addr_t in kernel space to
5624  *		user space, based on 32/64 bitness of the user space
5625  *
5626  * Parameters:	ua			User space address to copy to
5627  *		ptr			Address of kernel space user_addr_t
5628  *		ptr_size		4/8, based on 'ua' address space
5629  *
5630  * Returns:	0			Success
5631  *		EFAULT			Bad 'ua'
5632  *
5633  */
5634 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)5635 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
5636 {
5637 	int error;
5638 
5639 	if (ptr_size == 4) {
5640 		/* 64 bit value containing 32 bit address */
5641 		unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua);   /* SAFE */
5642 
5643 		error = copyout(&i, ptr, 4);
5644 	} else {
5645 		error = copyout(&ua, ptr, 8);
5646 	}
5647 	return error;
5648 }
5649 
5650 
5651 /*
5652  * exec_copyout_strings
5653  *
5654  * Copy out the strings segment to user space.  The strings segment is put
5655  * on a preinitialized stack frame.
5656  *
5657  * Parameters:	struct image_params *	the image parameter block
5658  *		int *			a pointer to the stack offset variable
5659  *
5660  * Returns:	0			Success
5661  *		!0			Faiure: errno
5662  *
5663  * Implicit returns:
5664  *		(*stackp)		The stack offset, modified
5665  *
5666  * Note:	The strings segment layout is backward, from the beginning
5667  *		of the top of the stack to consume the minimal amount of
5668  *		space possible; the returned stack pointer points to the
5669  *		end of the area consumed (stacks grow downward).
5670  *
5671  *		argc is an int; arg[i] are pointers; env[i] are pointers;
5672  *		the 0's are (void *)NULL's
5673  *
5674  * The stack frame layout is:
5675  *
5676  *      +-------------+ <- p->user_stack
5677  *      |     16b     |
5678  *      +-------------+
5679  *      | STRING AREA |
5680  *      |      :      |
5681  *      |      :      |
5682  *      |      :      |
5683  *      +- -- -- -- --+
5684  *      |  PATH AREA  |
5685  *      +-------------+
5686  *      |      0      |
5687  *      +-------------+
5688  *      |  applev[n]  |
5689  *      +-------------+
5690  *             :
5691  *             :
5692  *      +-------------+
5693  *      |  applev[1]  |
5694  *      +-------------+
5695  *      | exec_path / |
5696  *      |  applev[0]  |
5697  *      +-------------+
5698  *      |      0      |
5699  *      +-------------+
5700  *      |    env[n]   |
5701  *      +-------------+
5702  *             :
5703  *             :
5704  *      +-------------+
5705  *      |    env[0]   |
5706  *      +-------------+
5707  *      |      0      |
5708  *      +-------------+
5709  *      | arg[argc-1] |
5710  *      +-------------+
5711  *             :
5712  *             :
5713  *      +-------------+
5714  *      |    arg[0]   |
5715  *      +-------------+
5716  *      |     argc    |
5717  * sp-> +-------------+
5718  *
5719  * Although technically a part of the STRING AREA, we treat the PATH AREA as
5720  * a separate entity.  This allows us to align the beginning of the PATH AREA
5721  * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
5722  * which preceed it on the stack are properly aligned.
5723  */
5724 __attribute__((noinline))
5725 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)5726 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
5727 {
5728 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5729 	int     ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5730 	int     ptr_area_size;
5731 	void *ptr_buffer_start, *ptr_buffer;
5732 	size_t string_size;
5733 
5734 	user_addr_t     string_area;    /* *argv[], *env[] */
5735 	user_addr_t     ptr_area;       /* argv[], env[], applev[] */
5736 	user_addr_t argc_area;  /* argc */
5737 	user_addr_t     stack;
5738 	int error;
5739 
5740 	unsigned i;
5741 	struct copyout_desc {
5742 		char    *start_string;
5743 		int             count;
5744 #if CONFIG_DTRACE
5745 		user_addr_t     *dtrace_cookie;
5746 #endif
5747 		boolean_t       null_term;
5748 	} descriptors[] = {
5749 		{
5750 			.start_string = imgp->ip_startargv,
5751 			.count = imgp->ip_argc,
5752 #if CONFIG_DTRACE
5753 			.dtrace_cookie = &p->p_dtrace_argv,
5754 #endif
5755 			.null_term = TRUE
5756 		},
5757 		{
5758 			.start_string = imgp->ip_endargv,
5759 			.count = imgp->ip_envc,
5760 #if CONFIG_DTRACE
5761 			.dtrace_cookie = &p->p_dtrace_envp,
5762 #endif
5763 			.null_term = TRUE
5764 		},
5765 		{
5766 			.start_string = imgp->ip_strings,
5767 			.count = 1,
5768 #if CONFIG_DTRACE
5769 			.dtrace_cookie = NULL,
5770 #endif
5771 			.null_term = FALSE
5772 		},
5773 		{
5774 			.start_string = imgp->ip_endenvv,
5775 			.count = imgp->ip_applec - 1, /* exec_path handled above */
5776 #if CONFIG_DTRACE
5777 			.dtrace_cookie = NULL,
5778 #endif
5779 			.null_term = TRUE
5780 		}
5781 	};
5782 
5783 	stack = *stackp;
5784 
5785 	/*
5786 	 * All previous contributors to the string area
5787 	 * should have aligned their sub-area
5788 	 */
5789 	if (imgp->ip_strspace % ptr_size != 0) {
5790 		error = EINVAL;
5791 		goto bad;
5792 	}
5793 
5794 	/* Grow the stack down for the strings we've been building up */
5795 	string_size = imgp->ip_strendp - imgp->ip_strings;
5796 	stack -= string_size;
5797 	string_area = stack;
5798 
5799 	/*
5800 	 * Need room for one pointer for each string, plus
5801 	 * one for the NULLs terminating the argv, envv, and apple areas.
5802 	 */
5803 	ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5804 	stack -= ptr_area_size;
5805 	ptr_area = stack;
5806 
5807 	/* We'll construct all the pointer arrays in our string buffer,
5808 	 * which we already know is aligned properly, and ip_argspace
5809 	 * was used to verify we have enough space.
5810 	 */
5811 	ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5812 
5813 	/*
5814 	 * Need room for pointer-aligned argc slot.
5815 	 */
5816 	stack -= ptr_size;
5817 	argc_area = stack;
5818 
5819 	/*
5820 	 * Record the size of the arguments area so that sysctl_procargs()
5821 	 * can return the argument area without having to parse the arguments.
5822 	 */
5823 	proc_lock(p);
5824 	p->p_argc = imgp->ip_argc;
5825 	p->p_argslen = (int)(*stackp - string_area);
5826 	proc_unlock(p);
5827 
5828 	/* Return the initial stack address: the location of argc */
5829 	*stackp = stack;
5830 
5831 	/*
5832 	 * Copy out the entire strings area.
5833 	 */
5834 	error = copyout(imgp->ip_strings, string_area,
5835 	    string_size);
5836 	if (error) {
5837 		goto bad;
5838 	}
5839 
5840 	for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
5841 		char *cur_string = descriptors[i].start_string;
5842 		int j;
5843 
5844 #if CONFIG_DTRACE
5845 		if (descriptors[i].dtrace_cookie) {
5846 			proc_lock(p);
5847 			*descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
5848 			proc_unlock(p);
5849 		}
5850 #endif /* CONFIG_DTRACE */
5851 
5852 		/*
5853 		 * For each segment (argv, envv, applev), copy as many pointers as requested
5854 		 * to our pointer buffer.
5855 		 */
5856 		for (j = 0; j < descriptors[i].count; j++) {
5857 			user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
5858 
5859 			/* Copy out the pointer to the current string. Alignment has been verified  */
5860 			if (ptr_size == 8) {
5861 				*(uint64_t *)ptr_buffer = (uint64_t)cur_address;
5862 			} else {
5863 				*(uint32_t *)ptr_buffer = (uint32_t)cur_address;
5864 			}
5865 
5866 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5867 			cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
5868 		}
5869 
5870 		if (descriptors[i].null_term) {
5871 			if (ptr_size == 8) {
5872 				*(uint64_t *)ptr_buffer = 0ULL;
5873 			} else {
5874 				*(uint32_t *)ptr_buffer = 0;
5875 			}
5876 
5877 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5878 		}
5879 	}
5880 
5881 	/*
5882 	 * Copy out all our pointer arrays in bulk.
5883 	 */
5884 	error = copyout(ptr_buffer_start, ptr_area,
5885 	    ptr_area_size);
5886 	if (error) {
5887 		goto bad;
5888 	}
5889 
5890 	/* argc (int32, stored in a ptr_size area) */
5891 	error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
5892 	if (error) {
5893 		goto bad;
5894 	}
5895 
5896 bad:
5897 	return error;
5898 }
5899 
5900 
5901 /*
5902  * exec_extract_strings
5903  *
5904  * Copy arguments and environment from user space into work area; we may
5905  * have already copied some early arguments into the work area, and if
5906  * so, any arguments opied in are appended to those already there.
5907  * This function is the primary manipulator of ip_argspace, since
5908  * these are the arguments the client of execve(2) knows about. After
5909  * each argv[]/envv[] string is copied, we charge the string length
5910  * and argv[]/envv[] pointer slot to ip_argspace, so that we can
5911  * full preflight the arg list size.
5912  *
5913  * Parameters:	struct image_params *	the image parameter block
5914  *
5915  * Returns:	0			Success
5916  *		!0			Failure: errno
5917  *
5918  * Implicit returns;
5919  *		(imgp->ip_argc)		Count of arguments, updated
5920  *		(imgp->ip_envc)		Count of environment strings, updated
5921  *		(imgp->ip_argspace)	Count of remaining of NCARGS
5922  *		(imgp->ip_interp_buffer)	Interpreter and args (mutated in place)
5923  *
5924  *
5925  * Note:	The argument and environment vectors are user space pointers
5926  *		to arrays of user space pointers.
5927  */
5928 __attribute__((noinline))
5929 static int
exec_extract_strings(struct image_params * imgp)5930 exec_extract_strings(struct image_params *imgp)
5931 {
5932 	int error = 0;
5933 	int     ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
5934 	int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5935 	user_addr_t     argv = imgp->ip_user_argv;
5936 	user_addr_t     envv = imgp->ip_user_envv;
5937 
5938 	/*
5939 	 * Adjust space reserved for the path name by however much padding it
5940 	 * needs. Doing this here since we didn't know if this would be a 32-
5941 	 * or 64-bit process back in exec_save_path.
5942 	 */
5943 	while (imgp->ip_strspace % new_ptr_size != 0) {
5944 		*imgp->ip_strendp++ = '\0';
5945 		imgp->ip_strspace--;
5946 		/* imgp->ip_argspace--; not counted towards exec args total */
5947 	}
5948 
5949 	/*
5950 	 * From now on, we start attributing string space to ip_argspace
5951 	 */
5952 	imgp->ip_startargv = imgp->ip_strendp;
5953 	imgp->ip_argc = 0;
5954 
5955 	if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
5956 		user_addr_t     arg;
5957 		char *argstart, *ch;
5958 
5959 		/* First, the arguments in the "#!" string are tokenized and extracted. */
5960 		argstart = imgp->ip_interp_buffer;
5961 		while (argstart) {
5962 			ch = argstart;
5963 			while (*ch && !IS_WHITESPACE(*ch)) {
5964 				ch++;
5965 			}
5966 
5967 			if (*ch == '\0') {
5968 				/* last argument, no need to NUL-terminate */
5969 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5970 				argstart = NULL;
5971 			} else {
5972 				/* NUL-terminate */
5973 				*ch = '\0';
5974 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5975 
5976 				/*
5977 				 * Find the next string. We know spaces at the end of the string have already
5978 				 * been stripped.
5979 				 */
5980 				argstart = ch + 1;
5981 				while (IS_WHITESPACE(*argstart)) {
5982 					argstart++;
5983 				}
5984 			}
5985 
5986 			/* Error-check, regardless of whether this is the last interpreter arg or not */
5987 			if (error) {
5988 				goto bad;
5989 			}
5990 			if (imgp->ip_argspace < new_ptr_size) {
5991 				error = E2BIG;
5992 				goto bad;
5993 			}
5994 			imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5995 			imgp->ip_argc++;
5996 		}
5997 
5998 		if (argv != 0LL) {
5999 			/*
6000 			 * If we are running an interpreter, replace the av[0] that was
6001 			 * passed to execve() with the path name that was
6002 			 * passed to execve() for interpreters which do not use the PATH
6003 			 * to locate their script arguments.
6004 			 */
6005 			error = copyinptr(argv, &arg, ptr_size);
6006 			if (error) {
6007 				goto bad;
6008 			}
6009 			if (arg != 0LL) {
6010 				argv += ptr_size; /* consume without using */
6011 			}
6012 		}
6013 
6014 		if (imgp->ip_interp_sugid_fd != -1) {
6015 			char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
6016 			snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
6017 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
6018 		} else {
6019 			error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
6020 		}
6021 
6022 		if (error) {
6023 			goto bad;
6024 		}
6025 		if (imgp->ip_argspace < new_ptr_size) {
6026 			error = E2BIG;
6027 			goto bad;
6028 		}
6029 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6030 		imgp->ip_argc++;
6031 	}
6032 
6033 	while (argv != 0LL) {
6034 		user_addr_t     arg;
6035 
6036 		error = copyinptr(argv, &arg, ptr_size);
6037 		if (error) {
6038 			goto bad;
6039 		}
6040 
6041 		if (arg == 0LL) {
6042 			break;
6043 		}
6044 
6045 		argv += ptr_size;
6046 
6047 		/*
6048 		 * av[n...] = arg[n]
6049 		 */
6050 		error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
6051 		if (error) {
6052 			goto bad;
6053 		}
6054 		if (imgp->ip_argspace < new_ptr_size) {
6055 			error = E2BIG;
6056 			goto bad;
6057 		}
6058 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6059 		imgp->ip_argc++;
6060 	}
6061 
6062 	/* Save space for argv[] NULL terminator */
6063 	if (imgp->ip_argspace < new_ptr_size) {
6064 		error = E2BIG;
6065 		goto bad;
6066 	}
6067 	imgp->ip_argspace -= new_ptr_size;
6068 
6069 	/* Note where the args ends and env begins. */
6070 	imgp->ip_endargv = imgp->ip_strendp;
6071 	imgp->ip_envc = 0;
6072 
6073 	/* Now, get the environment */
6074 	while (envv != 0LL) {
6075 		user_addr_t     env;
6076 
6077 		error = copyinptr(envv, &env, ptr_size);
6078 		if (error) {
6079 			goto bad;
6080 		}
6081 
6082 		envv += ptr_size;
6083 		if (env == 0LL) {
6084 			break;
6085 		}
6086 		/*
6087 		 * av[n...] = env[n]
6088 		 */
6089 		error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
6090 		if (error) {
6091 			goto bad;
6092 		}
6093 		if (imgp->ip_argspace < new_ptr_size) {
6094 			error = E2BIG;
6095 			goto bad;
6096 		}
6097 		imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
6098 		imgp->ip_envc++;
6099 	}
6100 
6101 	/* Save space for envv[] NULL terminator */
6102 	if (imgp->ip_argspace < new_ptr_size) {
6103 		error = E2BIG;
6104 		goto bad;
6105 	}
6106 	imgp->ip_argspace -= new_ptr_size;
6107 
6108 	/* Align the tail of the combined argv+envv area */
6109 	while (imgp->ip_strspace % new_ptr_size != 0) {
6110 		if (imgp->ip_argspace < 1) {
6111 			error = E2BIG;
6112 			goto bad;
6113 		}
6114 		*imgp->ip_strendp++ = '\0';
6115 		imgp->ip_strspace--;
6116 		imgp->ip_argspace--;
6117 	}
6118 
6119 	/* Note where the envv ends and applev begins. */
6120 	imgp->ip_endenvv = imgp->ip_strendp;
6121 
6122 	/*
6123 	 * From now on, we are no longer charging argument
6124 	 * space to ip_argspace.
6125 	 */
6126 
6127 bad:
6128 	return error;
6129 }
6130 
6131 /*
6132  * Libc has an 8-element array set up for stack guard values.  It only fills
6133  * in one of those entries, and both gcc and llvm seem to use only a single
6134  * 8-byte guard.  Until somebody needs more than an 8-byte guard value, don't
6135  * do the work to construct them.
6136  */
6137 #define GUARD_VALUES 1
6138 #define GUARD_KEY "stack_guard="
6139 
6140 /*
6141  * System malloc needs some entropy when it is initialized.
6142  */
6143 #define ENTROPY_VALUES 2
6144 #define ENTROPY_KEY "malloc_entropy="
6145 
6146 /*
6147  * libplatform needs a random pointer-obfuscation value when it is initialized.
6148  */
6149 #define PTR_MUNGE_VALUES 1
6150 #define PTR_MUNGE_KEY "ptr_munge="
6151 
6152 /*
6153  * System malloc engages nanozone for UIAPP.
6154  */
6155 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
6156 
6157 /*
6158  * Used to pass experiment flags up to libmalloc.
6159  */
6160 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
6161 
6162 /*
6163  * Passes information about hardened runtime entitlements to libsystem/libmalloc
6164  */
6165 #define HARDENED_RUNTIME_KEY "HardenedRuntime="
6166 
6167 #define PFZ_KEY "pfz="
6168 extern user32_addr_t commpage_text32_location;
6169 extern user64_addr_t commpage_text64_location;
6170 
6171 extern uuid_string_t bootsessionuuid_string;
6172 static TUNABLE(uint32_t, exe_boothash_salt, "exe_boothash_salt", 0);
6173 
6174 __startup_func
6175 static void
exe_boothash_salt_generate(void)6176 exe_boothash_salt_generate(void)
6177 {
6178 	if (!PE_parse_boot_argn("exe_boothash_salt", NULL, 0)) {
6179 		read_random(&exe_boothash_salt, sizeof(exe_boothash_salt));
6180 	}
6181 }
6182 STARTUP(EARLY_BOOT, STARTUP_RANK_MIDDLE, exe_boothash_salt_generate);
6183 
6184 
6185 #define MAIN_STACK_VALUES 4
6186 #define MAIN_STACK_KEY "main_stack="
6187 
6188 #define FSID_KEY "executable_file="
6189 #define DYLD_FSID_KEY "dyld_file="
6190 #define CDHASH_KEY "executable_cdhash="
6191 #define DYLD_FLAGS_KEY "dyld_flags="
6192 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
6193 #define APP_BOOT_SESSION_KEY "executable_boothash="
6194 #if __has_feature(ptrauth_calls)
6195 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
6196 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
6197 #endif /* __has_feature(ptrauth_calls) */
6198 #define MAIN_TH_PORT_KEY "th_port="
6199 
6200 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
6201 
6202 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
6203 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
6204 
6205 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6206 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
6207 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6208 
6209 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)6210 exec_add_entropy_key(struct image_params *imgp,
6211     const char *key,
6212     int values,
6213     boolean_t embedNUL)
6214 {
6215 	const int limit = 8;
6216 	uint64_t entropy[limit];
6217 	char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
6218 	if (values > limit) {
6219 		values = limit;
6220 	}
6221 
6222 	read_random(entropy, sizeof(entropy[0]) * values);
6223 
6224 	if (embedNUL) {
6225 		entropy[0] &= ~(0xffull << 8);
6226 	}
6227 
6228 	int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
6229 	size_t remaining = sizeof(str) - len;
6230 	for (int i = 1; i < values && remaining > 0; ++i) {
6231 		size_t start = sizeof(str) - remaining;
6232 		len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
6233 		remaining -= len;
6234 	}
6235 
6236 	return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
6237 }
6238 
6239 /*
6240  * Build up the contents of the apple[] string vector
6241  */
6242 #if (DEVELOPMENT || DEBUG)
6243 extern uint64_t dyld_flags;
6244 #endif
6245 
6246 #if __has_feature(ptrauth_calls)
6247 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)6248 is_arm64e_running_as_arm64(const struct image_params *imgp)
6249 {
6250 	return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
6251 	       (imgp->ip_flags & IMGPF_NOJOP);
6252 }
6253 #endif /* __has_feature(ptrauth_calls) */
6254 
6255 _Atomic uint64_t libmalloc_experiment_factors = 0;
6256 
6257 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result,task_t task)6258 exec_add_apple_strings(struct image_params *imgp,
6259     const load_result_t *load_result, task_t task)
6260 {
6261 	int error;
6262 	int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6263 	thread_t new_thread;
6264 	ipc_port_t sright;
6265 	uint64_t local_experiment_factors = 0;
6266 
6267 	/* exec_save_path stored the first string */
6268 	imgp->ip_applec = 1;
6269 
6270 	/* adding the pfz string */
6271 	{
6272 		char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
6273 
6274 		if (img_ptr_size == 8) {
6275 			__assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
6276 			assert(ret < sizeof(pfz_string));
6277 		} else {
6278 			snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
6279 		}
6280 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
6281 		if (error) {
6282 			printf("Failed to add the pfz string with error %d\n", error);
6283 			goto bad;
6284 		}
6285 		imgp->ip_applec++;
6286 	}
6287 
6288 	/* adding the NANO_ENGAGE_KEY key */
6289 	if (imgp->ip_px_sa) {
6290 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6291 		int proc_flags = psa->psa_flags;
6292 
6293 		if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
6294 			const char *nano_string = NANO_ENGAGE_KEY;
6295 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
6296 			if (error) {
6297 				goto bad;
6298 			}
6299 			imgp->ip_applec++;
6300 		}
6301 	}
6302 
6303 	/*
6304 	 * Supply libc with a collection of random values to use when
6305 	 * implementing -fstack-protector.
6306 	 *
6307 	 * (The first random string always contains an embedded NUL so that
6308 	 * __stack_chk_guard also protects against C string vulnerabilities)
6309 	 */
6310 	error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
6311 	if (error) {
6312 		goto bad;
6313 	}
6314 	imgp->ip_applec++;
6315 
6316 	/*
6317 	 * Supply libc with entropy for system malloc.
6318 	 */
6319 	error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
6320 	if (error) {
6321 		goto bad;
6322 	}
6323 	imgp->ip_applec++;
6324 
6325 	/*
6326 	 * Supply libpthread & libplatform with a random value to use for pointer
6327 	 * obfuscation.
6328 	 */
6329 	error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
6330 	if (error) {
6331 		goto bad;
6332 	}
6333 	imgp->ip_applec++;
6334 
6335 	/*
6336 	 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
6337 	 * stack if it was allocated by the kernel.
6338 	 *
6339 	 * The guard page is not included in this stack size as libpthread
6340 	 * expects to add it back in after receiving this value.
6341 	 */
6342 	if (load_result->unixproc) {
6343 		char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
6344 		snprintf(stack_string, sizeof(stack_string),
6345 		    MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
6346 		    (uint64_t)load_result->user_stack,
6347 		    (uint64_t)load_result->user_stack_size,
6348 		    (uint64_t)load_result->user_stack_alloc,
6349 		    (uint64_t)load_result->user_stack_alloc_size);
6350 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
6351 		if (error) {
6352 			goto bad;
6353 		}
6354 		imgp->ip_applec++;
6355 	}
6356 
6357 	if (imgp->ip_vattr) {
6358 		uint64_t fsid    = vnode_get_va_fsid(imgp->ip_vattr);
6359 		uint64_t fsobjid = imgp->ip_vattr->va_fileid;
6360 
6361 		char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6362 		snprintf(fsid_string, sizeof(fsid_string),
6363 		    FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
6364 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6365 		if (error) {
6366 			goto bad;
6367 		}
6368 		imgp->ip_applec++;
6369 	}
6370 
6371 	if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
6372 		char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6373 		snprintf(fsid_string, sizeof(fsid_string),
6374 		    DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
6375 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6376 		if (error) {
6377 			goto bad;
6378 		}
6379 		imgp->ip_applec++;
6380 	}
6381 
6382 	uint8_t cdhash[SHA1_RESULTLEN];
6383 	int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash, NULL);
6384 	if (cdhash_errror == 0) {
6385 		char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
6386 		strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
6387 		char *p = hash_string + sizeof(CDHASH_KEY) - 1;
6388 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6389 			snprintf(p, 3, "%02x", (int) cdhash[i]);
6390 			p += 2;
6391 		}
6392 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
6393 		if (error) {
6394 			goto bad;
6395 		}
6396 		imgp->ip_applec++;
6397 
6398 		/* hash together cd-hash and boot-session-uuid */
6399 		uint8_t sha_digest[SHA256_DIGEST_LENGTH];
6400 		SHA256_CTX sha_ctx;
6401 		SHA256_Init(&sha_ctx);
6402 		SHA256_Update(&sha_ctx, &exe_boothash_salt, sizeof(exe_boothash_salt));
6403 		SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
6404 		SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
6405 		SHA256_Final(sha_digest, &sha_ctx);
6406 		char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
6407 		strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
6408 		char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
6409 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6410 			snprintf(s, 3, "%02x", (int) sha_digest[i]);
6411 			s += 2;
6412 		}
6413 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
6414 		if (error) {
6415 			goto bad;
6416 		}
6417 		imgp->ip_applec++;
6418 	}
6419 #if (DEVELOPMENT || DEBUG)
6420 	if (dyld_flags) {
6421 		char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
6422 		snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
6423 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
6424 		if (error) {
6425 			goto bad;
6426 		}
6427 		imgp->ip_applec++;
6428 	}
6429 #endif
6430 	if (imgp->ip_subsystem_root_path) {
6431 		size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
6432 		char subsystem_root_path_string[buffer_len];
6433 		int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
6434 
6435 		if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
6436 			error = ENAMETOOLONG;
6437 			goto bad;
6438 		}
6439 
6440 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
6441 		if (error) {
6442 			goto bad;
6443 		}
6444 
6445 		imgp->ip_applec++;
6446 	}
6447 #if __has_feature(ptrauth_calls)
6448 	if (is_arm64e_running_as_arm64(imgp)) {
6449 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
6450 		if (error) {
6451 			goto bad;
6452 		}
6453 
6454 		imgp->ip_applec++;
6455 	}
6456 #endif /* __has_feature(ptrauth_calls) */
6457 
6458 
6459 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
6460 	{
6461 		char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
6462 		strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
6463 		bool allowAll = bootarg_arm64e_preview_abi;
6464 		strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
6465 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
6466 		if (error) {
6467 			goto bad;
6468 		}
6469 
6470 		imgp->ip_applec++;
6471 	}
6472 #endif
6473 	/*
6474 	 * Add main thread mach port name
6475 	 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
6476 	 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
6477 	 * against libpthread.
6478 	 */
6479 	if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
6480 		thread_reference(new_thread);
6481 		sright = convert_thread_to_port_pinned(new_thread);
6482 		task_t new_task = get_threadtask(new_thread);
6483 		mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
6484 		char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
6485 		snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
6486 
6487 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
6488 		if (error) {
6489 			goto bad;
6490 		}
6491 		imgp->ip_applec++;
6492 	}
6493 
6494 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6495 	if (imgp->ip_px_sa != NULL) {
6496 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6497 		if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
6498 			const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
6499 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
6500 			if (error) {
6501 				goto bad;
6502 			}
6503 			imgp->ip_applec++;
6504 		}
6505 	}
6506 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6507 
6508 	/* adding the libmalloc experiment string */
6509 	local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
6510 	if (__improbable(local_experiment_factors != 0)) {
6511 		char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
6512 
6513 		snprintf(
6514 			libmalloc_experiment_factors_string,
6515 			sizeof(libmalloc_experiment_factors_string),
6516 			LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
6517 			local_experiment_factors);
6518 		error = exec_add_user_string(
6519 			imgp,
6520 			CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
6521 			UIO_SYSSPACE,
6522 			FALSE);
6523 		if (error) {
6524 			printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
6525 			goto bad;
6526 		}
6527 		imgp->ip_applec++;
6528 	}
6529 
6530 	/*
6531 	 * Push down the task security configuration. To reduce confusion when userland parses the information
6532 	 * still push an empty security configuration if nothing is active.
6533 	 */
6534 	{
6535 		#define SECURITY_CONFIG_KEY "security_config="
6536 		char security_config_str[strlen(SECURITY_CONFIG_KEY) + HEX_STR_LEN + 1];
6537 
6538 		snprintf(security_config_str, sizeof(security_config_str),
6539 		    SECURITY_CONFIG_KEY "0x%x", task_get_security_config(task));
6540 
6541 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(security_config_str), UIO_SYSSPACE, FALSE);
6542 		if (error) {
6543 			printf("Failed to add the security config string with error %d\n", error);
6544 			goto bad;
6545 		}
6546 		imgp->ip_applec++;
6547 	}
6548 
6549 
6550 
6551 
6552 	if (load_result->hardened_runtime_binary) {
6553 		const size_t HR_STRING_SIZE = sizeof(HARDENED_RUNTIME_KEY) + HR_FLAGS_NUM_NIBBLES + 2 + 1;
6554 		char hardened_runtime[HR_STRING_SIZE];
6555 		snprintf(hardened_runtime, HR_STRING_SIZE, HARDENED_RUNTIME_KEY"0x%x", load_result->hardened_runtime_binary);
6556 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hardened_runtime), UIO_SYSSPACE, FALSE);
6557 		if (error) {
6558 			printf("Failed to add hardened runtime flag with error %d\n", error);
6559 			goto bad;
6560 		}
6561 		imgp->ip_applec++;
6562 	}
6563 	/* Align the tail of the combined applev area */
6564 	while (imgp->ip_strspace % img_ptr_size != 0) {
6565 		*imgp->ip_strendp++ = '\0';
6566 		imgp->ip_strspace--;
6567 	}
6568 
6569 bad:
6570 	return error;
6571 }
6572 
6573 /*
6574  * exec_check_permissions
6575  *
6576  * Description:	Verify that the file that is being attempted to be executed
6577  *		is in fact allowed to be executed based on it POSIX file
6578  *		permissions and other access control criteria
6579  *
6580  * Parameters:	struct image_params *	the image parameter block
6581  *
6582  * Returns:	0			Success
6583  *		EACCES			Permission denied
6584  *		ENOEXEC			Executable file format error
6585  *		ETXTBSY			Text file busy [misuse of error code]
6586  *	vnode_getattr:???
6587  *	vnode_authorize:???
6588  */
6589 static int
exec_check_permissions(struct image_params * imgp)6590 exec_check_permissions(struct image_params *imgp)
6591 {
6592 	struct vnode *vp = imgp->ip_vp;
6593 	struct vnode_attr *vap = imgp->ip_vattr;
6594 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6595 	int error;
6596 	kauth_action_t action;
6597 
6598 	/* Only allow execution of regular files */
6599 	if (!vnode_isreg(vp)) {
6600 		return EACCES;
6601 	}
6602 
6603 	/* Get the file attributes that we will be using here and elsewhere */
6604 	VATTR_INIT(vap);
6605 	VATTR_WANTED(vap, va_uid);
6606 	VATTR_WANTED(vap, va_gid);
6607 	VATTR_WANTED(vap, va_mode);
6608 	VATTR_WANTED(vap, va_fsid);
6609 	VATTR_WANTED(vap, va_fsid64);
6610 	VATTR_WANTED(vap, va_fileid);
6611 	VATTR_WANTED(vap, va_data_size);
6612 	if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
6613 		return error;
6614 	}
6615 
6616 	/*
6617 	 * Ensure that at least one execute bit is on - otherwise root
6618 	 * will always succeed, and we don't want to happen unless the
6619 	 * file really is executable.
6620 	 */
6621 	if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
6622 		return EACCES;
6623 	}
6624 
6625 	/* Disallow zero length files */
6626 	if (vap->va_data_size == 0) {
6627 		return ENOEXEC;
6628 	}
6629 
6630 	imgp->ip_arch_offset = (user_size_t)0;
6631 #if __LP64__
6632 	imgp->ip_arch_size = vap->va_data_size;
6633 #else
6634 	if (vap->va_data_size > UINT32_MAX) {
6635 		return ENOEXEC;
6636 	}
6637 	imgp->ip_arch_size = (user_size_t)vap->va_data_size;
6638 #endif
6639 
6640 	/* Disable setuid-ness for traced programs or if MNT_NOSUID */
6641 	if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
6642 		vap->va_mode &= ~(VSUID | VSGID);
6643 	}
6644 
6645 	/*
6646 	 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
6647 	 * flags for setuid/setgid binaries.
6648 	 */
6649 	if (vap->va_mode & (VSUID | VSGID)) {
6650 		imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
6651 	}
6652 
6653 #if CONFIG_MACF
6654 	error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
6655 	if (error) {
6656 		return error;
6657 	}
6658 #endif
6659 
6660 	/* Check for execute permission */
6661 	action = KAUTH_VNODE_EXECUTE;
6662 	/* Traced images must also be readable */
6663 	if (p->p_lflag & P_LTRACED) {
6664 		action |= KAUTH_VNODE_READ_DATA;
6665 	}
6666 	if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
6667 		return error;
6668 	}
6669 
6670 #if 0
6671 	/* Don't let it run if anyone had it open for writing */
6672 	vnode_lock(vp);
6673 	if (vp->v_writecount) {
6674 		panic("going to return ETXTBSY %x", vp);
6675 		vnode_unlock(vp);
6676 		return ETXTBSY;
6677 	}
6678 	vnode_unlock(vp);
6679 #endif
6680 
6681 	/* XXX May want to indicate to underlying FS that vnode is open */
6682 
6683 	return error;
6684 }
6685 
6686 
6687 /*
6688  * exec_handle_sugid
6689  *
6690  * Initially clear the P_SUGID in the process flags; if an SUGID process is
6691  * exec'ing a non-SUGID image, then  this is the point of no return.
6692  *
6693  * If the image being activated is SUGID, then replace the credential with a
6694  * copy, disable tracing (unless the tracing process is root), reset the
6695  * mach task port to revoke it, set the P_SUGID bit,
6696  *
6697  * If the saved user and group ID will be changing, then make sure it happens
6698  * to a new credential, rather than a shared one.
6699  *
6700  * Set the security token (this is probably obsolete, given that the token
6701  * should not technically be separate from the credential itself).
6702  *
6703  * Parameters:	struct image_params *	the image parameter block
6704  *
6705  * Returns:	void			No failure indication
6706  *
6707  * Implicit returns:
6708  *		<process credential>	Potentially modified/replaced
6709  *		<task port>		Potentially revoked
6710  *		<process flags>		P_SUGID bit potentially modified
6711  *		<security token>	Potentially modified
6712  */
6713 __attribute__((noinline))
6714 static int
exec_handle_sugid(struct image_params * imgp)6715 exec_handle_sugid(struct image_params *imgp)
6716 {
6717 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
6718 	kauth_cred_t            cred = vfs_context_ucred(imgp->ip_vfs_context);
6719 	int                     i;
6720 	int                     leave_sugid_clear = 0;
6721 	int                     mac_reset_ipc = 0;
6722 	int                     error = 0;
6723 #if CONFIG_MACF
6724 	int                     mac_transition, disjoint_cred = 0;
6725 	int             label_update_return = 0;
6726 
6727 	/*
6728 	 * Determine whether a call to update the MAC label will result in the
6729 	 * credential changing.
6730 	 *
6731 	 * Note:	MAC policies which do not actually end up modifying
6732 	 *		the label subsequently are strongly encouraged to
6733 	 *		return 0 for this check, since a non-zero answer will
6734 	 *		slow down the exec fast path for normal binaries.
6735 	 */
6736 	mac_transition = mac_cred_check_label_update_execve(
6737 		imgp->ip_vfs_context,
6738 		imgp->ip_vp,
6739 		imgp->ip_arch_offset,
6740 		imgp->ip_scriptvp,
6741 		imgp->ip_scriptlabelp,
6742 		imgp->ip_execlabelp,
6743 		p,
6744 		&imgp->ip_px_smpx);
6745 #endif
6746 
6747 	OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
6748 
6749 	/*
6750 	 * Order of the following is important; group checks must go last,
6751 	 * as we use the success of the 'ismember' check combined with the
6752 	 * failure of the explicit match to indicate that we will be setting
6753 	 * the egid of the process even though the new process did not
6754 	 * require VSUID/VSGID bits in order for it to set the new group as
6755 	 * its egid.
6756 	 *
6757 	 * Note:	Technically, by this we are implying a call to
6758 	 *		setegid() in the new process, rather than implying
6759 	 *		it used its VSGID bit to set the effective group,
6760 	 *		even though there is no code in that process to make
6761 	 *		such a call.
6762 	 */
6763 	if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
6764 	    kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
6765 	    ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
6766 	    ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
6767 	    (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
6768 #if CONFIG_MACF
6769 /* label for MAC transition and neither VSUID nor VSGID */
6770 handle_mac_transition:
6771 #endif
6772 
6773 #if CONFIG_SETUID
6774 		/*
6775 		 * Replace the credential with a copy of itself if euid or
6776 		 * egid change.
6777 		 *
6778 		 * Note:	setuid binaries will automatically opt out of
6779 		 *		group resolver participation as a side effect
6780 		 *		of this operation.  This is an intentional
6781 		 *		part of the security model, which requires a
6782 		 *		participating credential be established by
6783 		 *		escalating privilege, setting up all other
6784 		 *		aspects of the credential including whether
6785 		 *		or not to participate in external group
6786 		 *		membership resolution, then dropping their
6787 		 *		effective privilege to that of the desired
6788 		 *		final credential state.
6789 		 *
6790 		 * Modifications to p_ucred must be guarded using the
6791 		 * proc's ucred lock. This prevents others from accessing
6792 		 * a garbage credential.
6793 		 */
6794 
6795 		if (imgp->ip_origvattr->va_mode & VSUID) {
6796 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6797 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6798 				return kauth_cred_model_setresuid(model,
6799 				KAUTH_UID_NONE,
6800 				imgp->ip_origvattr->va_uid,
6801 				imgp->ip_origvattr->va_uid,
6802 				KAUTH_UID_NONE);
6803 			});
6804 		}
6805 
6806 		if (imgp->ip_origvattr->va_mode & VSGID) {
6807 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6808 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6809 				return kauth_cred_model_setresgid(model,
6810 				KAUTH_GID_NONE,
6811 				imgp->ip_origvattr->va_gid,
6812 				imgp->ip_origvattr->va_gid);
6813 			});
6814 		}
6815 #endif /* CONFIG_SETUID */
6816 
6817 #if CONFIG_MACF
6818 		/*
6819 		 * If a policy has indicated that it will transition the label,
6820 		 * before making the call into the MAC policies, get a new
6821 		 * duplicate credential, so they can modify it without
6822 		 * modifying any others sharing it.
6823 		 */
6824 		if (mac_transition) {
6825 			/*
6826 			 * This hook may generate upcalls that require
6827 			 * importance donation from the kernel.
6828 			 * (23925818)
6829 			 */
6830 			thread_t thread = current_thread();
6831 			thread_enable_send_importance(thread, TRUE);
6832 			kauth_proc_label_update_execve(p,
6833 			    imgp->ip_vfs_context,
6834 			    imgp->ip_vp,
6835 			    imgp->ip_arch_offset,
6836 			    imgp->ip_scriptvp,
6837 			    imgp->ip_scriptlabelp,
6838 			    imgp->ip_execlabelp,
6839 			    &imgp->ip_csflags,
6840 			    &imgp->ip_px_smpx,
6841 			    &disjoint_cred,                     /* will be non zero if disjoint */
6842 			    &label_update_return);
6843 			thread_enable_send_importance(thread, FALSE);
6844 
6845 			if (disjoint_cred) {
6846 				/*
6847 				 * If updating the MAC label resulted in a
6848 				 * disjoint credential, flag that we need to
6849 				 * set the P_SUGID bit.  This protects
6850 				 * against debuggers being attached by an
6851 				 * insufficiently privileged process onto the
6852 				 * result of a transition to a more privileged
6853 				 * credential.
6854 				 */
6855 				leave_sugid_clear = 0;
6856 			}
6857 
6858 			imgp->ip_mac_return = label_update_return;
6859 		}
6860 
6861 		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);
6862 
6863 #endif  /* CONFIG_MACF */
6864 
6865 		/*
6866 		 * If 'leave_sugid_clear' is non-zero, then we passed the
6867 		 * VSUID and MACF checks, and successfully determined that
6868 		 * the previous cred was a member of the VSGID group, but
6869 		 * that it was not the default at the time of the execve,
6870 		 * and that the post-labelling credential was not disjoint.
6871 		 * So we don't set the P_SUGID or reset mach ports and fds
6872 		 * on the basis of simply running this code.
6873 		 */
6874 		if (mac_reset_ipc || !leave_sugid_clear) {
6875 			/*
6876 			 * Have mach reset the task and thread ports.
6877 			 * We don't want anyone who had the ports before
6878 			 * a setuid exec to be able to access/control the
6879 			 * task/thread after.
6880 			 */
6881 			ipc_task_reset((imgp->ip_new_thread != NULL) ?
6882 			    get_threadtask(imgp->ip_new_thread) : proc_task(p));
6883 			ipc_thread_reset((imgp->ip_new_thread != NULL) ?
6884 			    imgp->ip_new_thread : current_thread());
6885 		}
6886 
6887 		if (!leave_sugid_clear) {
6888 			/*
6889 			 * Flag the process as setuid.
6890 			 */
6891 			OSBitOrAtomic(P_SUGID, &p->p_flag);
6892 
6893 			/*
6894 			 * Radar 2261856; setuid security hole fix
6895 			 * XXX For setuid processes, attempt to ensure that
6896 			 * stdin, stdout, and stderr are already allocated.
6897 			 * We do not want userland to accidentally allocate
6898 			 * descriptors in this range which has implied meaning
6899 			 * to libc.
6900 			 */
6901 			for (i = 0; i < 3; i++) {
6902 				if (fp_get_noref_locked(p, i) != NULL) {
6903 					continue;
6904 				}
6905 
6906 				/*
6907 				 * Do the kernel equivalent of
6908 				 *
6909 				 *      if i == 0
6910 				 *              (void) open("/dev/null", O_RDONLY);
6911 				 *      else
6912 				 *              (void) open("/dev/null", O_WRONLY);
6913 				 */
6914 
6915 				struct fileproc *fp;
6916 				int indx;
6917 				int flag;
6918 				struct nameidata *ndp = NULL;
6919 
6920 				if (i == 0) {
6921 					flag = FREAD;
6922 				} else {
6923 					flag = FWRITE;
6924 				}
6925 
6926 				if ((error = falloc_exec(p, imgp->ip_vfs_context,
6927 				    &fp, &indx)) != 0) {
6928 					continue;
6929 				}
6930 
6931 				ndp = kalloc_type(struct nameidata,
6932 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
6933 
6934 				NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
6935 				    CAST_USER_ADDR_T("/dev/null"),
6936 				    imgp->ip_vfs_context);
6937 
6938 				if ((error = vn_open(ndp, flag, 0)) != 0) {
6939 					fp_free(p, indx, fp);
6940 					kfree_type(struct nameidata, ndp);
6941 					break;
6942 				}
6943 
6944 				struct fileglob *fg = fp->fp_glob;
6945 
6946 				fg->fg_flag = flag;
6947 				fg->fg_ops = &vnops;
6948 				fp_set_data(fp, ndp->ni_vp);
6949 
6950 				vnode_put(ndp->ni_vp);
6951 
6952 				proc_fdlock(p);
6953 				procfdtbl_releasefd(p, indx, NULL);
6954 				fp_drop(p, indx, fp, 1);
6955 				proc_fdunlock(p);
6956 
6957 				kfree_type(struct nameidata, ndp);
6958 			}
6959 		}
6960 	}
6961 #if CONFIG_MACF
6962 	else {
6963 		/*
6964 		 * We are here because we were told that the MAC label will
6965 		 * be transitioned, and the binary is not VSUID or VSGID; to
6966 		 * deal with this case, we could either duplicate a lot of
6967 		 * code, or we can indicate we want to default the P_SUGID
6968 		 * bit clear and jump back up.
6969 		 */
6970 		if (mac_transition) {
6971 			leave_sugid_clear = 1;
6972 			goto handle_mac_transition;
6973 		}
6974 	}
6975 
6976 #endif  /* CONFIG_MACF */
6977 
6978 	/* Update the process' identity version and set the security token.
6979 	 * Also, ensure we always see a modified identity version (rdar://129775819).
6980 	 */
6981 	int previous_pid_version = proc_get_ro(p)->p_idversion;
6982 	int new_pid_version;
6983 	do {
6984 		new_pid_version = OSIncrementAtomic(&nextpidversion);
6985 	} while (new_pid_version == previous_pid_version);
6986 	proc_setpidversion(p, new_pid_version);
6987 	task_set_uniqueid(proc_task(p));
6988 
6989 	/*
6990 	 * Implement the semantic where the effective user and group become
6991 	 * the saved user and group in exec'ed programs.
6992 	 */
6993 	kauth_cred_proc_update(p, PROC_SETTOKEN_ALWAYS,
6994 	    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6995 		posix_cred_t pcred = posix_cred_get(model);
6996 
6997 		if (pcred->cr_svuid == pcred->cr_uid &&
6998 		pcred->cr_svgid == pcred->cr_gid) {
6999 		        return false;
7000 		}
7001 
7002 		pcred->cr_svuid = pcred->cr_uid;
7003 		pcred->cr_svgid = pcred->cr_gid;
7004 		return true;
7005 	});
7006 
7007 	return error;
7008 }
7009 
7010 
7011 /*
7012  * create_unix_stack
7013  *
7014  * Description:	Set the user stack address for the process to the provided
7015  *		address.  If a custom stack was not set as a result of the
7016  *		load process (i.e. as specified by the image file for the
7017  *		executable), then allocate the stack in the provided map and
7018  *		set up appropriate guard pages for enforcing administrative
7019  *		limits on stack growth, if they end up being needed.
7020  *
7021  * Parameters:	p			Process to set stack on
7022  *		load_result		Information from mach-o load commands
7023  *		map			Address map in which to allocate the new stack
7024  *
7025  * Returns:	KERN_SUCCESS		Stack successfully created
7026  *		!KERN_SUCCESS		Mach failure code
7027  */
7028 __attribute__((noinline))
7029 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)7030 create_unix_stack(vm_map_t map, load_result_t* load_result,
7031     proc_t p)
7032 {
7033 	mach_vm_size_t          size, prot_size;
7034 	mach_vm_offset_t        addr, prot_addr;
7035 	kern_return_t           kr;
7036 
7037 	mach_vm_address_t       user_stack = load_result->user_stack;
7038 
7039 	proc_lock(p);
7040 	p->user_stack = (uintptr_t)user_stack;
7041 	if (load_result->custom_stack) {
7042 		p->p_lflag |= P_LCUSTOM_STACK;
7043 	}
7044 	proc_unlock(p);
7045 	if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
7046 		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);
7047 	}
7048 
7049 	if (load_result->user_stack_alloc_size > 0) {
7050 		/*
7051 		 * Allocate enough space for the maximum stack size we
7052 		 * will ever authorize and an extra page to act as
7053 		 * a guard page for stack overflows. For default stacks,
7054 		 * vm_initial_limit_stack takes care of the extra guard page.
7055 		 * Otherwise we must allocate it ourselves.
7056 		 */
7057 		if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
7058 			return KERN_INVALID_ARGUMENT;
7059 		}
7060 		addr = vm_map_trunc_page(load_result->user_stack - size,
7061 		    vm_map_page_mask(map));
7062 		kr = mach_vm_allocate_kernel(map, &addr, size,
7063 		    VM_MAP_KERNEL_FLAGS_FIXED(.vm_tag = VM_MEMORY_STACK));
7064 		if (kr != KERN_SUCCESS) {
7065 			// Can't allocate at default location, try anywhere
7066 			addr = 0;
7067 			kr = mach_vm_allocate_kernel(map, &addr, size,
7068 			    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vm_tag = VM_MEMORY_STACK));
7069 			if (kr != KERN_SUCCESS) {
7070 				return kr;
7071 			}
7072 
7073 			user_stack = addr + size;
7074 			load_result->user_stack = (user_addr_t)user_stack;
7075 
7076 			proc_lock(p);
7077 			p->user_stack = (uintptr_t)user_stack;
7078 			proc_unlock(p);
7079 		}
7080 
7081 		load_result->user_stack_alloc = (user_addr_t)addr;
7082 
7083 		/*
7084 		 * And prevent access to what's above the current stack
7085 		 * size limit for this process.
7086 		 */
7087 		if (load_result->user_stack_size == 0) {
7088 			load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
7089 			prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
7090 		} else {
7091 			prot_size = PAGE_SIZE;
7092 		}
7093 
7094 		prot_addr = addr;
7095 		kr = mach_vm_protect(map,
7096 		    prot_addr,
7097 		    prot_size,
7098 		    FALSE,
7099 		    VM_PROT_NONE);
7100 		if (kr != KERN_SUCCESS) {
7101 			(void)mach_vm_deallocate(map, addr, size);
7102 			return kr;
7103 		}
7104 	}
7105 
7106 	return KERN_SUCCESS;
7107 }
7108 
7109 #include <sys/reboot.h>
7110 
7111 /*
7112  * load_init_program_at_path
7113  *
7114  * Description:	Load the "init" program; in most cases, this will be "launchd"
7115  *
7116  * Parameters:	p			Process to call execve() to create
7117  *					the "init" program
7118  *		scratch_addr		Page in p, scratch space
7119  *		path			NULL terminated path
7120  *
7121  * Returns:	KERN_SUCCESS		Success
7122  *		!KERN_SUCCESS           See execve/mac_execve for error codes
7123  *
7124  * Notes:	The process that is passed in is the first manufactured
7125  *		process on the system, and gets here via bsd_ast() firing
7126  *		for the first time.  This is done to ensure that bsd_init()
7127  *		has run to completion.
7128  *
7129  *		The address map of the first manufactured process matches the
7130  *		word width of the kernel. Once the self-exec completes, the
7131  *		initproc might be different.
7132  */
7133 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)7134 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
7135 {
7136 	int retval[2];
7137 	int error;
7138 	struct execve_args init_exec_args;
7139 	user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
7140 
7141 	/*
7142 	 * Validate inputs and pre-conditions
7143 	 */
7144 	assert(p);
7145 	assert(scratch_addr);
7146 	assert(path);
7147 
7148 	/*
7149 	 * Copy out program name.
7150 	 */
7151 	size_t path_length = strlen(path) + 1;
7152 	argv0 = scratch_addr;
7153 	error = copyout(path, argv0, path_length);
7154 	if (error) {
7155 		return error;
7156 	}
7157 
7158 	scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
7159 
7160 	/*
7161 	 * Put out first (and only) argument, similarly.
7162 	 * Assumes everything fits in a page as allocated above.
7163 	 */
7164 	if (boothowto & RB_SINGLE) {
7165 		const char *init_args = "-s";
7166 		size_t init_args_length = strlen(init_args) + 1;
7167 
7168 		argv1 = scratch_addr;
7169 		error = copyout(init_args, argv1, init_args_length);
7170 		if (error) {
7171 			return error;
7172 		}
7173 
7174 		scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
7175 	}
7176 
7177 	if (proc_is64bit(p)) {
7178 		user64_addr_t argv64bit[3] = {};
7179 
7180 		argv64bit[0] = argv0;
7181 		argv64bit[1] = argv1;
7182 		argv64bit[2] = USER_ADDR_NULL;
7183 
7184 		error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
7185 		if (error) {
7186 			return error;
7187 		}
7188 	} else {
7189 		user32_addr_t argv32bit[3] = {};
7190 
7191 		argv32bit[0] = (user32_addr_t)argv0;
7192 		argv32bit[1] = (user32_addr_t)argv1;
7193 		argv32bit[2] = USER_ADDR_NULL;
7194 
7195 		error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
7196 		if (error) {
7197 			return error;
7198 		}
7199 	}
7200 
7201 	/*
7202 	 * Set up argument block for fake call to execve.
7203 	 */
7204 	init_exec_args.fname = argv0;
7205 	init_exec_args.argp = scratch_addr;
7206 	init_exec_args.envp = USER_ADDR_NULL;
7207 
7208 	/*
7209 	 * So that init task is set with uid,gid 0 token
7210 	 *
7211 	 * The access to the cred is safe:
7212 	 * the proc isn't running yet, it's stable.
7213 	 */
7214 	set_security_token(p, proc_ucred_unsafe(p));
7215 
7216 	return execve(p, &init_exec_args, retval);
7217 }
7218 
7219 static const char * init_programs[] = {
7220 #if DEBUG
7221 	"/usr/appleinternal/sbin/launchd.debug",
7222 #endif
7223 #if DEVELOPMENT || DEBUG
7224 	"/usr/appleinternal/sbin/launchd.development",
7225 #endif
7226 	"/sbin/launchd",
7227 };
7228 
7229 /*
7230  * load_init_program
7231  *
7232  * Description:	Load the "init" program; in most cases, this will be "launchd"
7233  *
7234  * Parameters:	p			Process to call execve() to create
7235  *					the "init" program
7236  *
7237  * Returns:	(void)
7238  *
7239  * Notes:	The process that is passed in is the first manufactured
7240  *		process on the system, and gets here via bsd_ast() firing
7241  *		for the first time.  This is done to ensure that bsd_init()
7242  *		has run to completion.
7243  *
7244  *		In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
7245  *		may be used to select a specific launchd executable. As with
7246  *		the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
7247  *		will force /sbin/launchd to be selected.
7248  *
7249  *              Search order by build:
7250  *
7251  * DEBUG	DEVELOPMENT	RELEASE		PATH
7252  * ----------------------------------------------------------------------------------
7253  * 1		1		NA		/usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
7254  * 2		NA		NA		/usr/appleinternal/sbin/launchd.debug
7255  * 3		2		NA		/usr/appleinternal/sbin/launchd.development
7256  * 4		3		1		/sbin/launchd
7257  */
7258 void
load_init_program(proc_t p)7259 load_init_program(proc_t p)
7260 {
7261 	uint32_t i;
7262 	int error;
7263 	vm_map_t map = current_map();
7264 	mach_vm_offset_t scratch_addr = 0;
7265 	mach_vm_size_t map_page_size = vm_map_page_size(map);
7266 
7267 #if DEVELOPMENT || DEBUG
7268 	/* Use the opportunity to initialize exec's debug log stream */
7269 	exec_log_handle = os_log_create("com.apple.xnu.bsd", "exec");
7270 #endif /* DEVELOPMENT || DEBUG */
7271 
7272 	(void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size,
7273 	    VM_MAP_KERNEL_FLAGS_ANYWHERE());
7274 #if CONFIG_MEMORYSTATUS
7275 	(void) memorystatus_init_at_boot_snapshot();
7276 #endif /* CONFIG_MEMORYSTATUS */
7277 
7278 #if DEBUG || DEVELOPMENT
7279 	/* Check for boot-arg suffix first */
7280 	char launchd_suffix[64];
7281 	if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
7282 		char launchd_path[128];
7283 		boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
7284 		    (strcmp(launchd_suffix, "release") == 0));
7285 
7286 		if (is_release_suffix) {
7287 			printf("load_init_program: attempting to load /sbin/launchd\n");
7288 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
7289 			if (!error) {
7290 				return;
7291 			}
7292 
7293 			panic("Process 1 exec of launchd.release failed, errno %d", error);
7294 		} else {
7295 			strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
7296 			strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
7297 
7298 			printf("load_init_program: attempting to load %s\n", launchd_path);
7299 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
7300 			if (!error) {
7301 				return;
7302 			} else if (error != ENOENT) {
7303 				printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
7304 			}
7305 		}
7306 	}
7307 #endif
7308 
7309 	error = ENOENT;
7310 	for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
7311 		printf("load_init_program: attempting to load %s\n", init_programs[i]);
7312 		error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
7313 		if (!error) {
7314 			return;
7315 		} else if (error != ENOENT) {
7316 			printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
7317 		}
7318 	}
7319 
7320 	panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
7321 }
7322 
7323 /*
7324  * load_return_to_errno
7325  *
7326  * Description:	Convert a load_return_t (Mach error) to an errno (BSD error)
7327  *
7328  * Parameters:	lrtn			Mach error number
7329  *
7330  * Returns:	(int)			BSD error number
7331  *		0			Success
7332  *		EBADARCH		Bad architecture
7333  *		EBADMACHO		Bad Mach object file
7334  *		ESHLIBVERS		Bad shared library version
7335  *		ENOMEM			Out of memory/resource shortage
7336  *		EACCES			Access denied
7337  *		ENOENT			Entry not found (usually "file does
7338  *					does not exist")
7339  *		EIO			An I/O error occurred
7340  *		EBADEXEC		The executable is corrupt/unknown
7341  */
7342 static int
load_return_to_errno(load_return_t lrtn)7343 load_return_to_errno(load_return_t lrtn)
7344 {
7345 	switch (lrtn) {
7346 	case LOAD_SUCCESS:
7347 		return 0;
7348 	case LOAD_BADARCH:
7349 		return EBADARCH;
7350 	case LOAD_BADMACHO:
7351 	case LOAD_BADMACHO_UPX:
7352 		return EBADMACHO;
7353 	case LOAD_SHLIB:
7354 		return ESHLIBVERS;
7355 	case LOAD_NOSPACE:
7356 	case LOAD_RESOURCE:
7357 		return ENOMEM;
7358 	case LOAD_PROTECT:
7359 		return EACCES;
7360 	case LOAD_ENOENT:
7361 		return ENOENT;
7362 	case LOAD_IOERROR:
7363 		return EIO;
7364 	case LOAD_DECRYPTFAIL:
7365 		return EAUTH;
7366 	case LOAD_FAILURE:
7367 	default:
7368 		return EBADEXEC;
7369 	}
7370 }
7371 
7372 #include <mach/mach_types.h>
7373 #include <mach/vm_prot.h>
7374 #include <mach/semaphore.h>
7375 #include <mach/sync_policy.h>
7376 #include <kern/clock.h>
7377 #include <mach/kern_return.h>
7378 
7379 /*
7380  * execargs_alloc
7381  *
7382  * Description:	Allocate the block of memory used by the execve arguments.
7383  *		At the same time, we allocate a page so that we can read in
7384  *		the first page of the image.
7385  *
7386  * Parameters:	struct image_params *	the image parameter block
7387  *
7388  * Returns:	0			Success
7389  *		EINVAL			Invalid argument
7390  *		EACCES			Permission denied
7391  *		EINTR			Interrupted function
7392  *		ENOMEM			Not enough space
7393  *
7394  * Notes:	This is a temporary allocation into the kernel address space
7395  *		to enable us to copy arguments in from user space.  This is
7396  *		necessitated by not mapping the process calling execve() into
7397  *		the kernel address space during the execve() system call.
7398  *
7399  *		We assemble the argument and environment, etc., into this
7400  *		region before copying it as a single block into the child
7401  *		process address space (at the top or bottom of the stack,
7402  *		depending on which way the stack grows; see the function
7403  *		exec_copyout_strings() for details).
7404  *
7405  *		This ends up with a second (possibly unnecessary) copy compared
7406  *		with assembing the data directly into the child address space,
7407  *		instead, but since we cannot be guaranteed that the parent has
7408  *		not modified its environment, we can't really know that it's
7409  *		really a block there as well.
7410  */
7411 
7412 
7413 static int execargs_waiters = 0;
7414 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
7415 
7416 static void
execargs_lock_lock(void)7417 execargs_lock_lock(void)
7418 {
7419 	lck_mtx_lock_spin(&execargs_cache_lock);
7420 }
7421 
7422 static void
execargs_lock_unlock(void)7423 execargs_lock_unlock(void)
7424 {
7425 	lck_mtx_unlock(&execargs_cache_lock);
7426 }
7427 
7428 static wait_result_t
execargs_lock_sleep(void)7429 execargs_lock_sleep(void)
7430 {
7431 	return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
7432 }
7433 
7434 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)7435 execargs_purgeable_allocate(char **execarg_address)
7436 {
7437 	mach_vm_offset_t addr = 0;
7438 	kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
7439 	    BSD_PAGEABLE_SIZE_PER_EXEC,
7440 	    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vmf_purgeable = true));
7441 	*execarg_address = (char *)addr;
7442 	assert(kr == KERN_SUCCESS);
7443 	return kr;
7444 }
7445 
7446 static kern_return_t
execargs_purgeable_reference(void * execarg_address)7447 execargs_purgeable_reference(void *execarg_address)
7448 {
7449 	int state = VM_PURGABLE_NONVOLATILE;
7450 	kern_return_t kr = vm_map_purgable_control(bsd_pageable_map,
7451 	    (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7452 
7453 	assert(kr == KERN_SUCCESS);
7454 	return kr;
7455 }
7456 
7457 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)7458 execargs_purgeable_volatilize(void *execarg_address)
7459 {
7460 	int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
7461 	kern_return_t kr;
7462 	kr = vm_map_purgable_control(bsd_pageable_map,
7463 	    (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7464 
7465 	assert(kr == KERN_SUCCESS);
7466 
7467 	return kr;
7468 }
7469 
7470 static void
execargs_wakeup_waiters(void)7471 execargs_wakeup_waiters(void)
7472 {
7473 	thread_wakeup(&execargs_free_count);
7474 }
7475 
7476 static int
execargs_alloc(struct image_params * imgp)7477 execargs_alloc(struct image_params *imgp)
7478 {
7479 	kern_return_t kret;
7480 	wait_result_t res;
7481 	int i, cache_index = -1;
7482 
7483 	execargs_lock_lock();
7484 
7485 	while (execargs_free_count == 0) {
7486 		execargs_waiters++;
7487 		res = execargs_lock_sleep();
7488 		execargs_waiters--;
7489 		if (res != THREAD_AWAKENED) {
7490 			execargs_lock_unlock();
7491 			return EINTR;
7492 		}
7493 	}
7494 
7495 	execargs_free_count--;
7496 
7497 	for (i = 0; i < execargs_cache_size; i++) {
7498 		vm_offset_t element = execargs_cache[i];
7499 		if (element) {
7500 			cache_index = i;
7501 			imgp->ip_strings = (char *)(execargs_cache[i]);
7502 			execargs_cache[i] = 0;
7503 			break;
7504 		}
7505 	}
7506 
7507 	assert(execargs_free_count >= 0);
7508 
7509 	execargs_lock_unlock();
7510 
7511 	if (cache_index == -1) {
7512 		kret = execargs_purgeable_allocate(&imgp->ip_strings);
7513 	} else {
7514 		kret = execargs_purgeable_reference(imgp->ip_strings);
7515 	}
7516 
7517 	assert(kret == KERN_SUCCESS);
7518 	if (kret != KERN_SUCCESS) {
7519 		return ENOMEM;
7520 	}
7521 
7522 	/* last page used to read in file headers */
7523 	imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
7524 	imgp->ip_strendp = imgp->ip_strings;
7525 	imgp->ip_argspace = NCARGS;
7526 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
7527 
7528 	return 0;
7529 }
7530 
7531 /*
7532  * execargs_free
7533  *
7534  * Description:	Free the block of memory used by the execve arguments and the
7535  *		first page of the executable by a previous call to the function
7536  *		execargs_alloc().
7537  *
7538  * Parameters:	struct image_params *	the image parameter block
7539  *
7540  * Returns:	0			Success
7541  *		EINVAL			Invalid argument
7542  *		EINTR			Oeration interrupted
7543  */
7544 static int
execargs_free(struct image_params * imgp)7545 execargs_free(struct image_params *imgp)
7546 {
7547 	kern_return_t kret;
7548 	int i;
7549 	boolean_t needs_wakeup = FALSE;
7550 
7551 	kret = execargs_purgeable_volatilize(imgp->ip_strings);
7552 
7553 	execargs_lock_lock();
7554 	execargs_free_count++;
7555 
7556 	for (i = 0; i < execargs_cache_size; i++) {
7557 		vm_offset_t element = execargs_cache[i];
7558 		if (element == 0) {
7559 			execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
7560 			imgp->ip_strings = NULL;
7561 			break;
7562 		}
7563 	}
7564 
7565 	assert(imgp->ip_strings == NULL);
7566 
7567 	if (execargs_waiters > 0) {
7568 		needs_wakeup = TRUE;
7569 	}
7570 
7571 	execargs_lock_unlock();
7572 
7573 	if (needs_wakeup == TRUE) {
7574 		execargs_wakeup_waiters();
7575 	}
7576 
7577 	return kret == KERN_SUCCESS ? 0 : EINVAL;
7578 }
7579 
7580 void
uthread_set_exec_data(struct uthread * uth,struct image_params * imgp)7581 uthread_set_exec_data(struct uthread *uth, struct image_params *imgp)
7582 {
7583 	uth->uu_save.uus_exec_data.imgp = imgp;
7584 }
7585 
7586 size_t
thread_get_current_exec_path(char * path,size_t size)7587 thread_get_current_exec_path(char *path, size_t size)
7588 {
7589 	struct uthread *uth = current_uthread();
7590 	struct image_params *imgp = uth->uu_save.uus_exec_data.imgp;
7591 	size_t string_size = 0;
7592 	char *exec_path;
7593 
7594 	if (path == NULL || imgp == NULL || imgp->ip_strings == NULL) {
7595 		return 0;
7596 	}
7597 
7598 	exec_path = imgp->ip_strings + strlen(EXECUTABLE_KEY);
7599 	string_size = imgp->ip_strendp - exec_path;
7600 	string_size = MIN(MAXPATHLEN, string_size);
7601 	string_size = MIN(size, string_size);
7602 
7603 	string_size = strlcpy(path, exec_path, string_size);
7604 	return string_size;
7605 }
7606 static void
exec_resettextvp(proc_t p,struct image_params * imgp)7607 exec_resettextvp(proc_t p, struct image_params *imgp)
7608 {
7609 	vnode_t vp;
7610 	off_t offset;
7611 	vnode_t tvp  = p->p_textvp;
7612 	int ret;
7613 
7614 	vp = imgp->ip_vp;
7615 	offset = imgp->ip_arch_offset;
7616 
7617 	if (vp == NULLVP) {
7618 		panic("exec_resettextvp: expected valid vp");
7619 	}
7620 
7621 	ret = vnode_ref(vp);
7622 	proc_lock(p);
7623 	if (ret == 0) {
7624 		p->p_textvp = vp;
7625 		p->p_textoff = offset;
7626 	} else {
7627 		p->p_textvp = NULLVP;   /* this is paranoia */
7628 		p->p_textoff = 0;
7629 	}
7630 	proc_unlock(p);
7631 
7632 	if (tvp != NULLVP) {
7633 		if (vnode_getwithref(tvp) == 0) {
7634 			vnode_rele(tvp);
7635 			vnode_put(tvp);
7636 		}
7637 	}
7638 }
7639 
7640 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
7641 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
7642 
7643 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)7644 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
7645 {
7646 	static char const nibble[] = "0123456789abcdef";
7647 
7648 	/* Apparently still the safest way to get a hex representation
7649 	 * of binary data.
7650 	 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
7651 	 * <rdar://problem/33328859> confusion around %*D/%nD in printf
7652 	 */
7653 	for (int i = 0; i < CS_CDHASH_LEN; ++i) {
7654 		str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
7655 		str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
7656 	}
7657 	str[CS_CDHASH_STRING_SIZE - 1] = 0;
7658 }
7659 
7660 /*
7661  * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
7662  *
7663  * Description: Waits for the userspace daemon to respond to the request
7664  *              we made. Function declared non inline to be visible in
7665  *		stackshots and spindumps as well as debugging.
7666  */
7667 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)7668 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
7669 {
7670 	return find_code_signature(task_access_port, new_pid);
7671 }
7672 
7673 /*
7674  * Update signature dependent process state, called by
7675  * process_signature.
7676  */
7677 static int
proc_process_signature(proc_t p,os_reason_t * signature_failure_reason)7678 proc_process_signature(proc_t p, os_reason_t *signature_failure_reason)
7679 {
7680 	int error = 0;
7681 	char const *error_msg = NULL;
7682 
7683 	kern_return_t kr = machine_task_process_signature(proc_get_task_raw(p), proc_platform(p), proc_sdk(p), &error_msg);
7684 
7685 	if (kr != KERN_SUCCESS) {
7686 		error = EINVAL;
7687 
7688 		if (error_msg != NULL) {
7689 			uint32_t error_msg_len = (uint32_t)strlen(error_msg) + 1;
7690 			mach_vm_address_t data_addr = 0;
7691 			int reason_error = 0;
7692 			int kcdata_error = 0;
7693 
7694 			os_reason_t reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7695 			reason->osr_flags = OS_REASON_FLAG_GENERATE_CRASH_REPORT | OS_REASON_FLAG_CONSISTENT_FAILURE;
7696 
7697 			if ((reason_error = os_reason_alloc_buffer_noblock(reason,
7698 			    kcdata_estimate_required_buffer_size(1, error_msg_len))) == 0 &&
7699 			    (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
7700 			    EXIT_REASON_USER_DESC, error_msg_len,
7701 			    &data_addr)) == KERN_SUCCESS) {
7702 				kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
7703 				    error_msg, error_msg_len);
7704 
7705 				if (mc_error != KERN_SUCCESS) {
7706 					printf("process_signature: failed to copy reason string (kcdata_memcpy error: %d)\n",
7707 					    mc_error);
7708 				}
7709 			} else {
7710 				printf("failed to allocate space for reason string (os_reason_alloc_buffer error: %d, kcdata error: %d, length: %u)\n",
7711 				    reason_error, kcdata_error, error_msg_len);
7712 			}
7713 
7714 			assert(*signature_failure_reason == NULL); // shouldn't have gotten so far
7715 			*signature_failure_reason = reason;
7716 		}
7717 	}
7718 	return error;
7719 }
7720 
7721 static int
process_signature(proc_t p,struct image_params * imgp)7722 process_signature(proc_t p, struct image_params *imgp)
7723 {
7724 	mach_port_t port = IPC_PORT_NULL;
7725 	kern_return_t kr = KERN_FAILURE;
7726 	int error = EACCES;
7727 	boolean_t unexpected_failure = FALSE;
7728 	struct cs_blob *csb;
7729 	boolean_t require_success = FALSE;
7730 	int spawn = (imgp->ip_flags & IMGPF_SPAWN);
7731 	const int vfexec = 0;
7732 	os_reason_t signature_failure_reason = OS_REASON_NULL;
7733 
7734 	/*
7735 	 * Override inherited code signing flags with the
7736 	 * ones for the process that is being successfully
7737 	 * loaded
7738 	 */
7739 	proc_lock(p);
7740 	proc_csflags_update(p, imgp->ip_csflags);
7741 	proc_unlock(p);
7742 
7743 	/* Set the switch_protect flag on the map */
7744 	if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
7745 		vm_map_switch_protect(get_task_map(proc_task(p)), TRUE);
7746 	}
7747 	/* set the cs_enforced flags in the map */
7748 	if (proc_getcsflags(p) & CS_ENFORCEMENT) {
7749 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), TRUE);
7750 	} else {
7751 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), FALSE);
7752 	}
7753 
7754 	/*
7755 	 * image activation may be failed due to policy
7756 	 * which is unexpected but security framework does not
7757 	 * approve of exec, kill and return immediately.
7758 	 */
7759 	if (imgp->ip_mac_return != 0) {
7760 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7761 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
7762 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7763 		error = imgp->ip_mac_return;
7764 		unexpected_failure = TRUE;
7765 		goto done;
7766 	}
7767 
7768 	if (imgp->ip_cs_error != OS_REASON_NULL) {
7769 		signature_failure_reason = imgp->ip_cs_error;
7770 		imgp->ip_cs_error = OS_REASON_NULL;
7771 		error = EACCES;
7772 		goto done;
7773 	}
7774 
7775 	/* call the launch constraints hook */
7776 	os_reason_t launch_constraint_reason;
7777 	if ((error = mac_proc_check_launch_constraints(p, imgp, &launch_constraint_reason)) != 0) {
7778 		signature_failure_reason = launch_constraint_reason;
7779 		goto done;
7780 	}
7781 
7782 #if XNU_TARGET_OS_OSX
7783 	/* Check for platform passed in spawn attr if iOS binary is being spawned */
7784 	if (proc_platform(p) == PLATFORM_IOS) {
7785 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
7786 		if (psa == NULL || psa->psa_platform == 0) {
7787 			boolean_t no_sandbox_entitled = FALSE;
7788 #if DEBUG || DEVELOPMENT
7789 			/*
7790 			 * Allow iOS binaries to spawn on internal systems
7791 			 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
7792 			 * boot-arg set to true
7793 			 */
7794 			if (unentitled_ios_sim_launch) {
7795 				no_sandbox_entitled = TRUE;
7796 			} else {
7797 				no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
7798 				    (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
7799 			}
7800 #endif /* DEBUG || DEVELOPMENT */
7801 			if (!no_sandbox_entitled) {
7802 				signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7803 				    EXEC_EXIT_REASON_WRONG_PLATFORM);
7804 				error = EACCES;
7805 				goto done;
7806 			}
7807 			printf("Allowing spawn of iOS binary %s since it has "
7808 			    "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
7809 			    "boot-arg set to true\n", p->p_name);
7810 		} else if (psa->psa_platform != PLATFORM_IOS) {
7811 			/* Simulator binary spawned with wrong platform */
7812 			signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7813 			    EXEC_EXIT_REASON_WRONG_PLATFORM);
7814 			error = EACCES;
7815 			goto done;
7816 		} else {
7817 			printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
7818 			    p->p_name);
7819 		}
7820 	}
7821 #endif /* XNU_TARGET_OS_OSX */
7822 
7823 	/* If the code signature came through the image activation path, we skip the
7824 	 * taskgated / externally attached path. */
7825 	if (imgp->ip_csflags & CS_SIGNED) {
7826 		error = 0;
7827 		goto done;
7828 	}
7829 
7830 	/* The rest of the code is for signatures that either already have been externally
7831 	 * attached (likely, but not necessarily by a previous run through the taskgated
7832 	 * path), or that will now be attached by taskgated. */
7833 
7834 	kr = task_get_task_access_port(proc_task(p), &port);
7835 	if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
7836 		error = 0;
7837 		if (require_success) {
7838 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7839 			    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
7840 			signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
7841 			error = EACCES;
7842 		}
7843 		goto done;
7844 	}
7845 
7846 	/*
7847 	 * taskgated returns KERN_SUCCESS if it has completed its work
7848 	 * and the exec should continue, KERN_FAILURE if the exec should
7849 	 * fail, or it may error out with different error code in an
7850 	 * event of mig failure (e.g. process was signalled during the
7851 	 * rpc call, taskgated died, mig server died etc.).
7852 	 */
7853 
7854 	kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
7855 	switch (kr) {
7856 	case KERN_SUCCESS:
7857 		error = 0;
7858 		break;
7859 	case KERN_FAILURE:
7860 		error = EACCES;
7861 
7862 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7863 		    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
7864 		signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
7865 		goto done;
7866 	default:
7867 		error = EACCES;
7868 
7869 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7870 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
7871 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
7872 		unexpected_failure = TRUE;
7873 		goto done;
7874 	}
7875 
7876 	/* Only do this if exec_resettextvp() did not fail */
7877 	if (p->p_textvp != NULLVP) {
7878 		csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
7879 
7880 		if (csb != NULL) {
7881 			/* As the enforcement we can do here is very limited, we only allow things that
7882 			 * are the only reason why this code path still exists:
7883 			 * Adhoc signed non-platform binaries without special cs_flags and without any
7884 			 * entitlements (unrestricted ones still pass AMFI). */
7885 			if (
7886 				/* Revalidate the blob if necessary through bumped generation count. */
7887 				(ubc_cs_generation_check(p->p_textvp) == 0 ||
7888 				ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
7889 				/* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
7890 				(csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
7891 				/* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
7892 				csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
7893 				CSSLOT_SIGNATURESLOT,
7894 				CSMAGIC_BLOBWRAPPER) == NULL &&
7895 				/* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
7896 				csb->csb_platform_binary == 0 &&
7897 				/* No entitlements, not even unrestricted ones. */
7898 				csb->csb_entitlements_blob == NULL &&
7899 				csb->csb_der_entitlements_blob == NULL) {
7900 				proc_lock(p);
7901 				proc_csflags_set(p, CS_SIGNED | CS_VALID);
7902 				proc_unlock(p);
7903 			} else {
7904 				uint8_t cdhash[CS_CDHASH_LEN];
7905 				char cdhash_string[CS_CDHASH_STRING_SIZE];
7906 				proc_getcdhash(p, cdhash);
7907 				cdhash_to_string(cdhash_string, cdhash);
7908 				printf("ignoring detached code signature on '%s' with cdhash '%s' "
7909 				    "because it is invalid, or not a simple adhoc signature.\n",
7910 				    p->p_name, cdhash_string);
7911 			}
7912 		}
7913 	}
7914 
7915 done:
7916 	if (0 == error) {
7917 		/*
7918 		 * Update the new process's signature-dependent process state.
7919 		 * state.
7920 		 */
7921 
7922 		error = proc_process_signature(p, &signature_failure_reason);
7923 	}
7924 
7925 	if (0 == error) {
7926 		/*
7927 		 * Update the new main thread's signature-dependent thread
7928 		 * state. This was also called when the thread was created,
7929 		 * but for the main thread the signature was not yet attached
7930 		 * at that time.
7931 		 */
7932 		kr = thread_process_signature(imgp->ip_new_thread, proc_get_task_raw(p));
7933 
7934 		if (kr != KERN_SUCCESS) {
7935 			error = EINVAL;
7936 			signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MACHINE_THREAD);
7937 		}
7938 	}
7939 
7940 	if (0 == error) {
7941 		/* The process's code signature related properties are
7942 		 * fully set up, so this is an opportune moment to log
7943 		 * platform binary execution, if desired. */
7944 		if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
7945 			uint8_t cdhash[CS_CDHASH_LEN];
7946 			char cdhash_string[CS_CDHASH_STRING_SIZE];
7947 			proc_getcdhash(p, cdhash);
7948 			cdhash_to_string(cdhash_string, cdhash);
7949 
7950 			os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
7951 			    "'%s' with cdhash %s\n", p->p_name, cdhash_string);
7952 		}
7953 	} else {
7954 		if (!unexpected_failure) {
7955 			proc_csflags_set(p, CS_KILLED);
7956 		}
7957 		/* make very sure execution fails */
7958 		if (vfexec || spawn) {
7959 			assert(signature_failure_reason != OS_REASON_NULL);
7960 			psignal_vfork_with_reason(p, proc_task(p), imgp->ip_new_thread,
7961 			    SIGKILL, signature_failure_reason);
7962 			signature_failure_reason = OS_REASON_NULL;
7963 			error = 0;
7964 		} else {
7965 			assert(signature_failure_reason != OS_REASON_NULL);
7966 			psignal_with_reason(p, SIGKILL, signature_failure_reason);
7967 			signature_failure_reason = OS_REASON_NULL;
7968 		}
7969 	}
7970 
7971 	if (port != IPC_PORT_NULL) {
7972 		ipc_port_release_send(port);
7973 	}
7974 
7975 	/* If we hit this, we likely would have leaked an exit reason */
7976 	assert(signature_failure_reason == OS_REASON_NULL);
7977 	return error;
7978 }
7979 
7980 /*
7981  * Typically as soon as we start executing this process, the
7982  * first instruction will trigger a VM fault to bring the text
7983  * pages (as executable) into the address space, followed soon
7984  * thereafter by dyld data structures (for dynamic executable).
7985  * To optimize this, as well as improve support for hardware
7986  * debuggers that can only access resident pages present
7987  * in the process' page tables, we prefault some pages if
7988  * possible. Errors are non-fatal.
7989  */
7990 #ifndef PREVENT_CALLER_STACK_USE
7991 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
7992 #endif
7993 
7994 /*
7995  * Prefaulting dyld data does not work (rdar://76621401)
7996  */
7997 #define FIXED_76621401 0
7998 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(__unused proc_t p,__unused struct image_params * imgp,__unused load_result_t * load_result)7999 exec_prefault_data(
8000 	__unused proc_t p,
8001 	__unused struct image_params *imgp,
8002 	__unused load_result_t *load_result)
8003 {
8004 #if FIXED_76621401
8005 	int ret;
8006 	size_t expected_all_image_infos_size;
8007 #endif /* FIXED_76621401 */
8008 	kern_return_t kr;
8009 
8010 	/*
8011 	 * Prefault executable or dyld entry point.
8012 	 */
8013 	if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8014 		DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
8015 	}
8016 	kr = vm_fault(current_map(),
8017 	    vm_map_trunc_page(load_result->entry_point,
8018 	    vm_map_page_mask(current_map())),
8019 	    VM_PROT_READ | VM_PROT_EXECUTE,
8020 	    FALSE, VM_KERN_MEMORY_NONE,
8021 	    THREAD_UNINT, NULL, 0);
8022 	if (kr != KERN_SUCCESS) {
8023 		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);
8024 	}
8025 
8026 #if FIXED_76621401
8027 	if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
8028 		expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
8029 	} else {
8030 		expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
8031 	}
8032 
8033 	/* Decode dyld anchor structure from <mach-o/dyld_images.h> */
8034 	if (load_result->dynlinker &&
8035 	    load_result->all_image_info_addr &&
8036 	    load_result->all_image_info_size >= expected_all_image_infos_size) {
8037 		union {
8038 			struct user64_dyld_all_image_infos      infos64;
8039 			struct user32_dyld_all_image_infos      infos32;
8040 		} all_image_infos;
8041 
8042 		/*
8043 		 * Pre-fault to avoid copyin() going through the trap handler
8044 		 * and recovery path.
8045 		 */
8046 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8047 			DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
8048 		}
8049 		kr = vm_fault(current_map(),
8050 		    vm_map_trunc_page(load_result->all_image_info_addr,
8051 		    vm_map_page_mask(current_map())),
8052 		    VM_PROT_READ | VM_PROT_WRITE,
8053 		    FALSE, VM_KERN_MEMORY_NONE,
8054 		    THREAD_UNINT, NULL, 0);
8055 		if (kr != KERN_SUCCESS) {
8056 //			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);
8057 		}
8058 		if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
8059 			/* all_image_infos straddles a page */
8060 			kr = vm_fault(current_map(),
8061 			    vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
8062 			    vm_map_page_mask(current_map())),
8063 			    VM_PROT_READ | VM_PROT_WRITE,
8064 			    FALSE, VM_KERN_MEMORY_NONE,
8065 			    THREAD_UNINT, NULL, 0);
8066 			if (kr != KERN_SUCCESS) {
8067 //				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);
8068 			}
8069 		}
8070 
8071 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8072 			DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
8073 		}
8074 		ret = copyin((user_addr_t)load_result->all_image_info_addr,
8075 		    &all_image_infos,
8076 		    expected_all_image_infos_size);
8077 		if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
8078 			user_addr_t notification_address;
8079 			user_addr_t dyld_image_address;
8080 			user_addr_t dyld_version_address;
8081 			user_addr_t dyld_all_image_infos_address;
8082 			user_addr_t dyld_slide_amount;
8083 
8084 			if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
8085 				notification_address = (user_addr_t)all_image_infos.infos64.notification;
8086 				dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
8087 				dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
8088 				dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
8089 			} else {
8090 				notification_address = all_image_infos.infos32.notification;
8091 				dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
8092 				dyld_version_address = all_image_infos.infos32.dyldVersion;
8093 				dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
8094 			}
8095 
8096 			/*
8097 			 * dyld statically sets up the all_image_infos in its Mach-O
8098 			 * binary at static link time, with pointers relative to its default
8099 			 * load address. Since ASLR might slide dyld before its first
8100 			 * instruction is executed, "dyld_slide_amount" tells us how far
8101 			 * dyld was loaded compared to its default expected load address.
8102 			 * All other pointers into dyld's image should be adjusted by this
8103 			 * amount. At some point later, dyld will fix up pointers to take
8104 			 * into account the slide, at which point the all_image_infos_address
8105 			 * field in the structure will match the runtime load address, and
8106 			 * "dyld_slide_amount" will be 0, if we were to consult it again.
8107 			 */
8108 
8109 			dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
8110 
8111 #if 0
8112 			kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
8113 			    (uint64_t)load_result->all_image_info_addr,
8114 			    all_image_infos.infos32.version,
8115 			    (uint64_t)notification_address,
8116 			    (uint64_t)dyld_image_address,
8117 			    (uint64_t)dyld_version_address,
8118 			    (uint64_t)dyld_all_image_infos_address);
8119 #endif
8120 
8121 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8122 				DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
8123 			}
8124 			kr = vm_fault(current_map(),
8125 			    vm_map_trunc_page(notification_address + dyld_slide_amount,
8126 			    vm_map_page_mask(current_map())),
8127 			    VM_PROT_READ | VM_PROT_EXECUTE,
8128 			    FALSE, VM_KERN_MEMORY_NONE,
8129 			    THREAD_UNINT, NULL, 0);
8130 			if (kr != KERN_SUCCESS) {
8131 //				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);
8132 			}
8133 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8134 				DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
8135 			}
8136 			kr = vm_fault(current_map(),
8137 			    vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
8138 			    vm_map_page_mask(current_map())),
8139 			    VM_PROT_READ | VM_PROT_EXECUTE,
8140 			    FALSE, VM_KERN_MEMORY_NONE,
8141 			    THREAD_UNINT, NULL, 0);
8142 			if (kr != KERN_SUCCESS) {
8143 //				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);
8144 			}
8145 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8146 				DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
8147 			}
8148 			kr = vm_fault(current_map(),
8149 			    vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
8150 			    vm_map_page_mask(current_map())),
8151 			    VM_PROT_READ,
8152 			    FALSE, VM_KERN_MEMORY_NONE,
8153 			    THREAD_UNINT, NULL, 0);
8154 			if (kr != KERN_SUCCESS) {
8155 //				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);
8156 			}
8157 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8158 				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);
8159 			}
8160 			kr = vm_fault(current_map(),
8161 			    vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
8162 			    vm_map_page_mask(current_map())),
8163 			    VM_PROT_READ | VM_PROT_WRITE,
8164 			    FALSE, VM_KERN_MEMORY_NONE,
8165 			    THREAD_UNINT, NULL, 0);
8166 			if (kr != KERN_SUCCESS) {
8167 //				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);
8168 			}
8169 		}
8170 	}
8171 #endif /* FIXED_76621401 */
8172 }
8173 
8174 static int
8175 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
8176 {
8177 #pragma unused(oidp, arg2, req)
8178 	int changed;
8179 	errno_t error;
8180 	uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
8181 
8182 	error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
8183 	if (error) {
8184 		return error;
8185 	}
8186 
8187 	if (changed) {
8188 		os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
8189 	}
8190 
8191 	return 0;
8192 }
8193 
8194 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
8195 
8196 SYSCTL_NODE(_kern, OID_AUTO, sec_transition,
8197     CTLFLAG_RD | CTLFLAG_LOCKED, 0, "sec_transition");
8198 
8199 #if DEBUG || DEVELOPMENT
8200 static int
sysctl_setup_ensure_pidversion_changes_on_exec(__unused int64_t in,int64_t * out)8201 sysctl_setup_ensure_pidversion_changes_on_exec(__unused int64_t in, int64_t *out)
8202 {
8203 	// Tweak nextpidversion to try to trigger a reuse (unless the exec code is doing the right thing)
8204 	int current_pid_version = proc_get_ro(current_proc())->p_idversion;
8205 	nextpidversion = current_pid_version;
8206 	*out = 0;
8207 	return KERN_SUCCESS;
8208 }
8209 
8210 SYSCTL_TEST_REGISTER(setup_ensure_pidversion_changes_on_exec, sysctl_setup_ensure_pidversion_changes_on_exec);
8211 #endif /* DEBUG || DEVELOPMENT */
8212