xref: /xnu-11215.41.3/bsd/kern/kern_exec.c (revision 33de042d024d46de5ff4e89f2471de6608e37fa4)
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/crypto/sha2.h>
122 #include <security/audit/audit.h>
123 
124 #include <ipc/ipc_types.h>
125 
126 #include <mach/mach_param.h>
127 #include <mach/mach_types.h>
128 #include <mach/port.h>
129 #include <mach/task.h>
130 #include <mach/task_access.h>
131 #include <mach/thread_act.h>
132 #include <mach/vm_map.h>
133 #include <mach/mach_vm.h>
134 #include <mach/vm_param.h>
135 #include <mach_debug/mach_debug_types.h>
136 
137 #include <kern/sched_prim.h> /* thread_wakeup() */
138 #include <kern/affinity.h>
139 #include <kern/assert.h>
140 #include <kern/task.h>
141 #include <kern/thread.h>
142 #include <kern/coalition.h>
143 #include <kern/policy_internal.h>
144 #include <kern/kalloc.h>
145 #include <kern/zalloc.h> /* zone_userspace_reboot_checks() */
146 
147 #include <os/log.h>
148 
149 #if CONFIG_MACF
150 #include <security/mac_framework.h>
151 #include <security/mac_mach_internal.h>
152 #endif
153 
154 #if CONFIG_AUDIT
155 #include <bsm/audit_kevents.h>
156 #endif
157 
158 #if CONFIG_ARCADE
159 #include <kern/arcade.h>
160 #endif
161 
162 #include <vm/vm_map_xnu.h>
163 #include <vm/vm_kern_xnu.h>
164 #include <vm/vm_protos.h>
165 #include <vm/vm_fault.h>
166 #include <vm/vm_pageout_xnu.h>
167 #include <vm/pmap.h>
168 #include <vm/vm_reclaim_xnu.h>
169 
170 #include <kdp/kdp_dyld.h>
171 
172 #include <machine/machine_routines.h>
173 #include <machine/pal_routines.h>
174 
175 #include <pexpert/pexpert.h>
176 
177 #if CONFIG_MEMORYSTATUS
178 #include <sys/kern_memorystatus.h>
179 #endif
180 
181 #include <IOKit/IOBSD.h>
182 
183 #include "kern_exec_internal.h"
184 
185 #include <CodeSignature/Entitlements.h>
186 
187 #include <mach/exclaves.h>
188 
189 
190 extern boolean_t vm_darkwake_mode;
191 
192 /* enable crash reports on various exec failures */
193 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
194 
195 #if XNU_TARGET_OS_OSX
196 #if __has_feature(ptrauth_calls)
197 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
198 #endif /* __has_feature(ptrauth_calls) */
199 
200 #if DEBUG || DEVELOPMENT
201 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
202 #endif /* DEBUG || DEVELOPMENT */
203 #endif /* XNU_TARGET_OS_OSX */
204 
205 #if CONFIG_DTRACE
206 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
207 extern void dtrace_proc_exec(proc_t);
208 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
209 
210 /*
211  * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
212  * we will store its value before actually calling it.
213  */
214 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
215 
216 #include <sys/dtrace_ptss.h>
217 #endif
218 
219 #if __has_feature(ptrauth_calls)
220 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
221     "vm_shared_region_per_team_id", 1);
222 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
223     "vm_shared_region_by_entitlement", 1);
224 
225 /* Upon userland request, reslide the shared cache. */
226 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
227     "vm_shared_region_reslide_aslr",
228 #if CONFIG_RESLIDE_SHARED_CACHE
229     1
230 #else
231     0
232 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
233     );
234 
235 /*
236  * Flag to control what processes should get shared cache randomize resliding
237  * after a fault in the shared cache region:
238  *
239  * 0 - all processes get a new randomized slide
240  * 1 - only platform processes get a new randomized slide
241  */
242 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
243     "vm_shared_region_reslide_restrict", 1);
244 
245 #if DEVELOPMENT || DEBUG
246 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
247     CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
248 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
249     CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
250 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
251     CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
252 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
253     CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
254 #endif
255 #endif /* __has_feature(ptrauth_calls) */
256 
257 #if DEVELOPMENT || DEBUG
258 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", true);
259 #else
260 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", false);
261 #endif
262 extern kern_return_t kern_register_userspace_coredump(task_t task, const char * name);
263 #define USERSPACE_COREDUMP_PANIC_ENTITLEMENT "com.apple.private.enable-coredump-on-panic"
264 #define USERSPACE_COREDUMP_PANIC_SEED_ENTITLEMENT \
265 	"com.apple.private.enable-coredump-on-panic-seed-privacy-approved"
266 
267 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
268 extern void task_set_did_exec_flag(task_t task);
269 extern void task_clear_exec_copy_flag(task_t task);
270 proc_t proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task,
271     task_t new_task, struct image_params *imgp, void **inherit);
272 boolean_t task_is_active(task_t);
273 boolean_t thread_is_active(thread_t thread);
274 void thread_copy_resource_info(thread_t dst_thread, thread_t src_thread);
275 void *ipc_importance_exec_switch_task(task_t old_task, task_t new_task);
276 extern void ipc_importance_release(void *elem);
277 extern boolean_t task_has_watchports(task_t task);
278 extern void task_set_no_smt(task_t task);
279 #if defined(HAS_APPLE_PAC)
280 char *task_get_vm_shared_region_id_and_jop_pid(task_t task, uint64_t *jop_pid);
281 #endif
282 task_t convert_port_to_task(ipc_port_t port);
283 
284 #if CONFIG_EXCLAVES
285 int task_add_conclave(task_t task, void *vnode, int64_t off, const char *task_conclave_id);
286 kern_return_t task_inherit_conclave(task_t old_task, task_t new_task, void *vnode, int64_t off);
287 #endif /* CONFIG_EXCLAVES */
288 
289 
290 /*
291  * Mach things for which prototypes are unavailable from Mach headers
292  */
293 #define IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND 0x1
294 void            ipc_task_enable(
295 	task_t          task);
296 void            ipc_task_reset(
297 	task_t          task);
298 void            ipc_thread_reset(
299 	thread_t        thread);
300 kern_return_t ipc_object_copyin(
301 	ipc_space_t             space,
302 	mach_port_name_t        name,
303 	mach_msg_type_name_t    msgt_name,
304 	ipc_object_t            *objectp,
305 	mach_port_context_t     context,
306 	mach_msg_guard_flags_t  *guard_flags,
307 	uint32_t                kmsg_flags);
308 void ipc_port_release_send(ipc_port_t);
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);
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 	int p_name_len = sizeof(p->p_name) - 1;
950 
951 	if (imgp->ip_ndp->ni_cnd.cn_namelen > p_name_len) {
952 		imgp->ip_ndp->ni_cnd.cn_namelen = p_name_len;
953 	}
954 
955 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name,
956 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
957 	p->p_name[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
958 
959 	if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN) {
960 		imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
961 	}
962 
963 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
964 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
965 	p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
966 
967 #if (DEVELOPMENT || DEBUG)
968 	/*
969 	 * This happens during image activation, so the crash behavior flags from
970 	 * posix_spawn will have already been set. So we don't have to worry about
971 	 * this being overridden.
972 	 */
973 	set_crash_behavior_from_bootarg(p);
974 #endif
975 }
976 
977 #if __has_feature(ptrauth_calls)
978 /**
979  * Returns a team ID string that may be used to assign a shared region.
980  *
981  * Platform binaries do not have team IDs and will return NULL.  Non-platform
982  * binaries without a team ID will be assigned an artificial team ID of ""
983  * (empty string) so that they will not be assigned to the default shared
984  * region.
985  *
986  * @param imgp image parameter block
987  * @return NULL if this is a platform binary, or an appropriate team ID string
988  *         otherwise
989  */
990 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)991 get_teamid_for_shared_region(struct image_params *imgp)
992 {
993 	assert(imgp->ip_vp != NULL);
994 
995 	const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
996 	if (ret) {
997 		return ret;
998 	}
999 
1000 	struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
1001 	if (csblob_get_platform_binary(blob)) {
1002 		return NULL;
1003 	} else {
1004 		static const char *NO_TEAM_ID = "";
1005 		return NO_TEAM_ID;
1006 	}
1007 }
1008 
1009 /**
1010  * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
1011  *
1012  * @param cpusubtype Mach-O style CPU subtype
1013  * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
1014  */
1015 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)1016 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
1017 {
1018 	return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1019 	       CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
1020 }
1021 
1022 #endif /* __has_feature(ptrauth_calls) */
1023 
1024 /**
1025  * Returns whether a type/subtype slice matches the requested
1026  * type/subtype.
1027  *
1028  * @param mask Bits to mask from the requested/tested cpu type
1029  * @param req_cpu Requested cpu type
1030  * @param req_subcpu Requested cpu subtype
1031  * @param test_cpu Tested slice cpu type
1032  * @param test_subcpu Tested slice cpu subtype
1033  */
1034 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)1035 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
1036     cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
1037     cpu_subtype_t test_subcpu)
1038 {
1039 	if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
1040 		return FALSE;
1041 	}
1042 
1043 	test_subcpu &= ~CPU_SUBTYPE_MASK;
1044 	req_subcpu  &= ~CPU_SUBTYPE_MASK;
1045 
1046 	if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
1047 		return FALSE;
1048 	}
1049 
1050 	return TRUE;
1051 }
1052 
1053 
1054 #define MIN_IOS_TPRO_SDK_VERSION        0x00100000
1055 #define MIN_OSX_TPRO_SDK_VERSION        0x000D0000
1056 #define MIN_TVOS_TPRO_SDK_VERSION       0x000D0000
1057 #define MIN_WATCHOS_TPRO_SDK_VERSION    0x00090000
1058 #define MIN_DRIVERKIT_TPRO_SDK_VERSION  0x00600000
1059 
1060 static void
exec_setup_tpro(struct image_params * imgp,load_result_t * load_result)1061 exec_setup_tpro(struct image_params *imgp, load_result_t *load_result)
1062 {
1063 	extern boolean_t xprr_tpro_enabled;
1064 	extern boolean_t enable_user_modifiable_perms;
1065 	uint32_t min_sdk_version = 0;
1066 
1067 	/* x86-64 translated code cannot take advantage of TPRO */
1068 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1069 		return;
1070 	}
1071 
1072 	/* Do not enable on 32-bit VA targets */
1073 	if (!(imgp->ip_flags & IMGPF_IS_64BIT_ADDR)) {
1074 		return;
1075 	}
1076 
1077 	switch (load_result->ip_platform) {
1078 	case PLATFORM_IOS:
1079 	case PLATFORM_IOSSIMULATOR:
1080 	case PLATFORM_MACCATALYST:
1081 		min_sdk_version = MIN_IOS_TPRO_SDK_VERSION;
1082 		break;
1083 	case PLATFORM_MACOS:
1084 		min_sdk_version = MIN_OSX_TPRO_SDK_VERSION;
1085 		break;
1086 	case PLATFORM_TVOS:
1087 	case PLATFORM_TVOSSIMULATOR:
1088 		min_sdk_version = MIN_TVOS_TPRO_SDK_VERSION;
1089 		break;
1090 	case PLATFORM_WATCHOS:
1091 	case PLATFORM_WATCHOSSIMULATOR:
1092 		min_sdk_version = MIN_WATCHOS_TPRO_SDK_VERSION;
1093 		break;
1094 	case PLATFORM_DRIVERKIT:
1095 		min_sdk_version = MIN_DRIVERKIT_TPRO_SDK_VERSION;
1096 		break;
1097 	default:
1098 		/* TPRO is on by default for newer platforms */
1099 		break;
1100 	}
1101 
1102 }
1103 
1104 /*
1105  * If the passed in executable's vnode should use the RSR
1106  * shared region, then this should return TRUE, otherwise, return FALSE.
1107  */
1108 static uint32_t rsr_current_version = 0;
1109 boolean_t (*rsr_check_vnode)(void *vnode) = NULL;
1110 
1111 boolean_t
vnode_is_rsr(vnode_t vp)1112 vnode_is_rsr(vnode_t vp)
1113 {
1114 	if (!(vnode_isreg(vp) && vnode_tag(vp) == VT_APFS)) {
1115 		return FALSE;
1116 	}
1117 
1118 	if (rsr_check_vnode != NULL && rsr_check_vnode((void *)vp)) {
1119 		return TRUE;
1120 	}
1121 	return FALSE;
1122 }
1123 
1124 
1125 // Check entitlements to see if this is a hardened runtime binary.
1126 // Save this in load_result until later for two purposes:
1127 // 1. Once the task is created, we can mark it as hardened runtime if needed
1128 // 2. we can propagate which entitlements are present to the apple array
1129 static inline void
encode_HR_entitlement(const char * entitlement,HR_flags_t mask,const struct image_params * imgp,load_result_t * load_result)1130 encode_HR_entitlement(const char *entitlement, HR_flags_t mask,
1131     const struct image_params *imgp, load_result_t *load_result)
1132 {
1133 	if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
1134 		load_result->hardened_runtime_binary |= mask;
1135 	}
1136 }
1137 
1138 uint32_t
rsr_get_version(void)1139 rsr_get_version(void)
1140 {
1141 	return os_atomic_load(&rsr_current_version, relaxed);
1142 }
1143 
1144 void
rsr_bump_version(void)1145 rsr_bump_version(void)
1146 {
1147 	os_atomic_inc(&rsr_current_version, relaxed);
1148 }
1149 
1150 #if XNU_TARGET_OS_OSX
1151 static int
1152 rsr_version_sysctl SYSCTL_HANDLER_ARGS
1153 {
1154 #pragma unused(arg1, arg2, oidp)
1155 	int value = rsr_get_version();
1156 	int error = SYSCTL_OUT(req, &value, sizeof(int));
1157 	if (error) {
1158 		return error;
1159 	}
1160 
1161 	if (!req->newptr) {
1162 		return 0;
1163 	}
1164 
1165 	error = SYSCTL_IN(req, &value, sizeof(int));
1166 	if (error) {
1167 		return error;
1168 	}
1169 	if (value != 0) {
1170 		rsr_bump_version();
1171 	}
1172 	return 0;
1173 }
1174 
1175 
1176 SYSCTL_PROC(_vm, OID_AUTO, shared_region_control,
1177     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
1178     0, 0, rsr_version_sysctl, "I", "");
1179 #endif /* XNU_TARGET_OS_OSX */
1180 
1181 /*
1182  * exec_mach_imgact
1183  *
1184  * Image activator for mach-o 1.0 binaries.
1185  *
1186  * Parameters;	struct image_params *	image parameter block
1187  *
1188  * Returns:	-1			not a fat binary (keep looking)
1189  *		-2			Success: encapsulated binary: reread
1190  *		>0			Failure: error number
1191  *		EBADARCH		Mach-o binary, but with an unrecognized
1192  *					architecture
1193  *		ENOMEM			No memory for child process after -
1194  *					can only happen after vfork()
1195  *
1196  * Important:	This image activator is NOT byte order neutral.
1197  *
1198  * Note:	A return value other than -1 indicates subsequent image
1199  *		activators should not be given the opportunity to attempt
1200  *		to activate the image.
1201  */
1202 static int
exec_mach_imgact(struct image_params * imgp)1203 exec_mach_imgact(struct image_params *imgp)
1204 {
1205 	struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1206 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
1207 	int                     error = 0;
1208 	task_t                  task;
1209 	task_t                  new_task = NULL; /* protected by vfexec */
1210 	thread_t                thread;
1211 	struct uthread          *uthread;
1212 	vm_map_t old_map = VM_MAP_NULL;
1213 	vm_map_t map = VM_MAP_NULL;
1214 	load_return_t           lret;
1215 	load_result_t           load_result = {};
1216 	struct _posix_spawnattr *psa = NULL;
1217 	int                     spawn = (imgp->ip_flags & IMGPF_SPAWN);
1218 	const int               vfexec = 0;
1219 	int                     exec = (imgp->ip_flags & IMGPF_EXEC);
1220 	os_reason_t             exec_failure_reason = OS_REASON_NULL;
1221 	boolean_t               reslide = FALSE;
1222 	char *                  userspace_coredump_name = NULL;
1223 
1224 	/*
1225 	 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1226 	 * is a reserved field on the end, so for the most part, we can
1227 	 * treat them as if they were identical. Reverse-endian Mach-O
1228 	 * binaries are recognized but not compatible.
1229 	 */
1230 	if ((mach_header->magic == MH_CIGAM) ||
1231 	    (mach_header->magic == MH_CIGAM_64)) {
1232 		error = EBADARCH;
1233 		goto bad;
1234 	}
1235 
1236 	if ((mach_header->magic != MH_MAGIC) &&
1237 	    (mach_header->magic != MH_MAGIC_64)) {
1238 		error = -1;
1239 		goto bad;
1240 	}
1241 
1242 	if (mach_header->filetype != MH_EXECUTE) {
1243 		error = -1;
1244 		goto bad;
1245 	}
1246 
1247 	if (imgp->ip_origcputype != 0) {
1248 		/* Fat header previously had an idea about this thin file */
1249 		if (imgp->ip_origcputype != mach_header->cputype ||
1250 		    imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1251 			error = EBADARCH;
1252 			goto bad;
1253 		}
1254 	} else {
1255 		imgp->ip_origcputype = mach_header->cputype;
1256 		imgp->ip_origcpusubtype = mach_header->cpusubtype;
1257 	}
1258 
1259 	task = current_task();
1260 	thread = current_thread();
1261 	uthread = get_bsdthread_info(thread);
1262 
1263 	if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1264 		imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1265 	}
1266 
1267 
1268 	/* If posix_spawn binprefs exist, respect those prefs. */
1269 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1270 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
1271 		int pr = 0;
1272 		for (pr = 0; pr < NBINPREFS; pr++) {
1273 			cpu_type_t pref = psa->psa_binprefs[pr];
1274 			cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1275 
1276 			if (pref == 0) {
1277 				/* No suitable arch in the pref list */
1278 				error = EBADARCH;
1279 				goto bad;
1280 			}
1281 
1282 			if (pref == CPU_TYPE_ANY) {
1283 				/* Jump to regular grading */
1284 				goto grade;
1285 			}
1286 
1287 			if (binary_match(CPU_ARCH_MASK, pref, subpref,
1288 			    imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1289 				goto grade;
1290 			}
1291 		}
1292 		error = EBADARCH;
1293 		goto bad;
1294 	}
1295 grade:
1296 	if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1297 	    imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1298 		error = EBADARCH;
1299 		goto bad;
1300 	}
1301 
1302 	if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1303 	    imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1304 #if __x86_64__
1305 		const char *excpath;
1306 		error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1307 		os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1308 #endif
1309 		error = EBADARCH;
1310 		goto bad;
1311 	}
1312 
1313 #if defined(HAS_APPLE_PAC)
1314 	assert(mach_header->cputype == CPU_TYPE_ARM64
1315 	    );
1316 
1317 	if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1318 	    arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1319 	    ) {
1320 		imgp->ip_flags &= ~IMGPF_NOJOP;
1321 	} else {
1322 		imgp->ip_flags |= IMGPF_NOJOP;
1323 	}
1324 #endif
1325 
1326 	/* Copy in arguments/environment from the old process */
1327 	error = exec_extract_strings(imgp);
1328 	if (error) {
1329 		goto bad;
1330 	}
1331 
1332 	AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1333 	    imgp->ip_endargv - imgp->ip_startargv);
1334 	AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1335 	    imgp->ip_endenvv - imgp->ip_endargv);
1336 
1337 
1338 
1339 	/* reset local idea of thread, uthread, task */
1340 	thread = imgp->ip_new_thread;
1341 	uthread = get_bsdthread_info(thread);
1342 	task = new_task = get_threadtask(thread);
1343 
1344 	/*
1345 	 *	Load the Mach-O file.
1346 	 *
1347 	 * NOTE: An error after this point  indicates we have potentially
1348 	 * destroyed or overwritten some process state while attempting an
1349 	 * execve() following a vfork(), which is an unrecoverable condition.
1350 	 * We send the new process an immediate SIGKILL to avoid it executing
1351 	 * any instructions in the mutated address space. For true spawns,
1352 	 * this is not the case, and "too late" is still not too late to
1353 	 * return an error code to the parent process.
1354 	 */
1355 
1356 	/*
1357 	 * Actually load the image file we previously decided to load.
1358 	 */
1359 	lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1360 	if (lret != LOAD_SUCCESS) {
1361 		error = load_return_to_errno(lret);
1362 
1363 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1364 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1365 		if (lret == LOAD_BADMACHO_UPX) {
1366 			set_proc_name(imgp, p);
1367 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1368 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1369 		} else {
1370 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1371 
1372 			if (bootarg_execfailurereports) {
1373 				set_proc_name(imgp, p);
1374 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1375 			}
1376 		}
1377 
1378 		exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1379 
1380 		goto badtoolate;
1381 	}
1382 
1383 	assert(imgp->ip_free_map == NULL);
1384 
1385 
1386 	// It's safe to check entitlements anytime after `load_machfile` if you check
1387 	// based on the vnode in imgp. We must perform this entitlement check
1388 	// before we start using load_result->hardened_runtime_binary further down
1389 	load_result.hardened_runtime_binary = 0;
1390 	encode_HR_entitlement(kCSWebBrowserHostEntitlement, BrowserHostEntitlementMask, imgp, &load_result);
1391 	encode_HR_entitlement(kCSWebBrowserGPUEntitlement, BrowserGPUEntitlementMask, imgp, &load_result);
1392 	encode_HR_entitlement(kCSWebBrowserNetworkEntitlement, BrowserNetworkEntitlementMask, imgp, &load_result);
1393 	encode_HR_entitlement(kCSWebBrowserWebContentEntitlement, BrowserWebContentEntitlementMask, imgp, &load_result);
1394 
1395 	/*
1396 	 * ERROR RECOVERY
1397 	 *
1398 	 * load_machfile() returned the new VM map ("map") but we haven't
1399 	 * committed to it yet.
1400 	 * Any error path between here and the point where we commit to using
1401 	 * the new "map" (with swap_task_map()) should deallocate "map".
1402 	 */
1403 
1404 #ifndef KASAN
1405 	/*
1406 	 * Security: zone sanity checks on fresh boot or initproc re-exec.
1407 	 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1408 	 * which means here is the earliest point we can assert on empty service port label zone,
1409 	 * after load_machfile() above terminates old launchd's IPC space.
1410 	 *
1411 	 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1412 	 * under quarantine.
1413 	 */
1414 	if (task_pid(task) == 1) {
1415 		zone_userspace_reboot_checks();
1416 	}
1417 #endif
1418 
1419 	proc_lock(p);
1420 	p->p_cputype = imgp->ip_origcputype;
1421 	p->p_cpusubtype = imgp->ip_origcpusubtype;
1422 	proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1423 	exec_setup_tpro(imgp, &load_result);
1424 
1425 	vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1426 	vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1427 	vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1428 #if XNU_TARGET_OS_OSX
1429 	if (proc_platform(p) == PLATFORM_IOS) {
1430 		assert(vm_map_is_alien(map));
1431 	} else {
1432 		assert(!vm_map_is_alien(map));
1433 	}
1434 #endif /* XNU_TARGET_OS_OSX */
1435 	proc_unlock(p);
1436 
1437 	/*
1438 	 * Set TPRO flags if enabled
1439 	 */
1440 
1441 	/*
1442 	 * Set code-signing flags if this binary is signed, or if parent has
1443 	 * requested them on exec.
1444 	 */
1445 	if (load_result.csflags & CS_VALID) {
1446 		imgp->ip_csflags |= load_result.csflags &
1447 		    (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1448 		    CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1449 		    CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1450 		    CS_ENTITLEMENT_FLAGS |
1451 		    CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1452 	} else {
1453 		imgp->ip_csflags &= ~CS_VALID;
1454 	}
1455 
1456 	if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1457 		imgp->ip_csflags |= CS_HARD;
1458 	}
1459 	if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1460 		imgp->ip_csflags |= CS_KILL;
1461 	}
1462 	if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1463 		imgp->ip_csflags |= CS_ENFORCEMENT;
1464 	}
1465 	if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1466 		if (proc_getcsflags(p) & CS_INSTALLER) {
1467 			imgp->ip_csflags |= CS_INSTALLER;
1468 		}
1469 		if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1470 			imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1471 		}
1472 		if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1473 			imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1474 		}
1475 	}
1476 
1477 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1478 	/*
1479 	 * ptrauth version 0 is a preview ABI.  Developers can opt into running
1480 	 * their own arm64e binaries for local testing, with the understanding
1481 	 * that future OSes may break ABI.
1482 	 */
1483 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1484 	    CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1485 	    !load_result.platform_binary &&
1486 	    !bootarg_arm64e_preview_abi) {
1487 		static bool logged_once = false;
1488 		set_proc_name(imgp, p);
1489 
1490 		printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1491 		if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1492 			printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1493 		}
1494 
1495 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1496 		if (bootarg_execfailurereports) {
1497 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1498 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1499 		}
1500 
1501 		/* release new address space since we won't use it */
1502 		imgp->ip_free_map = map;
1503 		map = VM_MAP_NULL;
1504 		goto badtoolate;
1505 	}
1506 
1507 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1508 	    imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1509 	    load_result.platform_binary &&
1510 	    (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1511 		set_proc_name(imgp, p);
1512 		printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
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 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1525 
1526 
1527 
1528 	/*
1529 	 * Set up the shared cache region in the new process.
1530 	 *
1531 	 * Normally there is a single shared region per architecture.
1532 	 * However on systems with Pointer Authentication, we can create
1533 	 * multiple shared caches with the amount of sharing determined
1534 	 * by team-id or entitlement. Inherited shared region IDs are used
1535 	 * for system processes that need to match and be able to inspect
1536 	 * a pre-existing task.
1537 	 */
1538 	int cpu_subtype = 0; /* all cpu_subtypes use the same shared region */
1539 #if __has_feature(ptrauth_calls)
1540 	char *shared_region_id = NULL;
1541 	size_t len;
1542 	char *base;
1543 	const char *cbase;
1544 #define HARDENED_RUNTIME_CONTENT_ID "C-"
1545 #define TEAM_ID_PREFIX "T-"
1546 #define ENTITLE_PREFIX "E-"
1547 #define SR_PREFIX_LEN  2
1548 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1549 
1550 	if (cpu_type() == CPU_TYPE_ARM64 &&
1551 	    arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1552 	    (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1553 		assertf(p->p_cputype == CPU_TYPE_ARM64,
1554 		    "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1555 		    p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1556 
1557 		/*
1558 		 * arm64e uses pointer authentication, so request a separate
1559 		 * shared region for this CPU subtype.
1560 		 */
1561 		cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1562 
1563 		/*
1564 		 * Determine which shared cache to select based on being told,
1565 		 * matching a team-id or matching an entitlement.
1566 		 */
1567 		if (load_result.hardened_runtime_binary & BrowserWebContentEntitlementMask) {
1568 			len = sizeof(HARDENED_RUNTIME_CONTENT_ID);
1569 			shared_region_id = kalloc_data(len, Z_WAITOK | Z_NOFAIL);
1570 			strlcpy(shared_region_id, HARDENED_RUNTIME_CONTENT_ID, len);
1571 		} else if (imgp->ip_inherited_shared_region_id) {
1572 			len = strlen(imgp->ip_inherited_shared_region_id);
1573 			shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1574 			memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1575 		} else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1576 			len = strlen(cbase);
1577 			if (vm_shared_region_per_team_id) {
1578 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1579 				    Z_WAITOK | Z_NOFAIL);
1580 				memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1581 				memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1582 			}
1583 		} else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1584 		    (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1585 			len = strlen(base);
1586 			if (vm_shared_region_by_entitlement) {
1587 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1588 				    Z_WAITOK | Z_NOFAIL);
1589 				memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1590 				memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1591 			}
1592 			/* Discard the copy of the entitlement */
1593 			kfree_data(base, len + 1);
1594 		}
1595 	}
1596 
1597 	if (imgp->ip_flags & IMGPF_RESLIDE) {
1598 		reslide = TRUE;
1599 	}
1600 
1601 	/* use "" as the default shared_region_id */
1602 	if (shared_region_id == NULL) {
1603 		shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1604 	}
1605 
1606 	/* ensure there's a unique pointer signing key for this shared_region_id */
1607 	shared_region_key_alloc(shared_region_id,
1608 	    imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1609 	task_set_shared_region_id(task, shared_region_id);
1610 	shared_region_id = NULL;
1611 #endif /* __has_feature(ptrauth_calls) */
1612 
1613 #if CONFIG_ROSETTA
1614 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1615 		OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
1616 	} else if (p->p_flag & P_TRANSLATED) {
1617 		OSBitAndAtomic(~P_TRANSLATED, &p->p_flag);
1618 	}
1619 #endif
1620 
1621 	int cputype = cpu_type();
1622 
1623 	uint32_t rsr_version = 0;
1624 #if XNU_TARGET_OS_OSX
1625 	if (vnode_is_rsr(imgp->ip_vp)) {
1626 		rsr_version = rsr_get_version();
1627 		os_atomic_or(&p->p_ladvflag, P_RSR, relaxed);
1628 		os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_ALTLINK, relaxed);
1629 	}
1630 #endif /* XNU_TARGET_OS_OSX */
1631 
1632 	vm_map_exec(map, task, load_result.is_64bit_addr,
1633 	    (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide,
1634 	    (imgp->ip_flags & IMGPF_DRIVER) != 0,
1635 	    rsr_version);
1636 
1637 	/*
1638 	 * Close file descriptors which specify close-on-exec.
1639 	 */
1640 	fdt_exec(p, vfs_context_ucred(imgp->ip_vfs_context),
1641 	    psa != NULL ? psa->psa_flags : 0, imgp->ip_new_thread, exec);
1642 
1643 	/*
1644 	 * deal with set[ug]id.
1645 	 */
1646 	error = exec_handle_sugid(imgp);
1647 	if (error) {
1648 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1649 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1650 
1651 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1652 		if (bootarg_execfailurereports) {
1653 			set_proc_name(imgp, p);
1654 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1655 		}
1656 
1657 		/* release new address space since we won't use it */
1658 		imgp->ip_free_map = map;
1659 		map = VM_MAP_NULL;
1660 		goto badtoolate;
1661 	}
1662 
1663 	/*
1664 	 * Commit to new map.
1665 	 *
1666 	 * Swap the new map for the old for target task, which consumes
1667 	 * our new map reference but each leaves us responsible for the
1668 	 * old_map reference.  That lets us get off the pmap associated
1669 	 * with it, and then we can release it.
1670 	 *
1671 	 * The map needs to be set on the target task which is different
1672 	 * than current task, thus swap_task_map is used instead of
1673 	 * vm_map_switch.
1674 	 */
1675 	old_map = swap_task_map(task, thread, map);
1676 #if MACH_ASSERT
1677 	/*
1678 	 * Reset the pmap's process info to prevent ledger checks
1679 	 * which might fail due to the ledgers being shared between
1680 	 * the old and new pmaps.
1681 	 */
1682 	vm_map_pmap_set_process(old_map, -1, "<old_map>");
1683 #endif /* MACH_ASSERT */
1684 	imgp->ip_free_map = old_map;
1685 	old_map = NULL;
1686 
1687 	lret = activate_exec_state(task, p, thread, &load_result);
1688 	if (lret != KERN_SUCCESS) {
1689 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1690 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1691 
1692 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1693 		if (bootarg_execfailurereports) {
1694 			set_proc_name(imgp, p);
1695 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1696 		}
1697 
1698 		goto badtoolate;
1699 	}
1700 
1701 	/*
1702 	 * deal with voucher on exec-calling thread.
1703 	 */
1704 	if (imgp->ip_new_thread == NULL) {
1705 		thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1706 	}
1707 
1708 	/* Make sure we won't interrupt ourself signalling a partial process */
1709 	if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1710 		psignal(p, SIGTRAP);
1711 	}
1712 
1713 	if (load_result.unixproc &&
1714 	    create_unix_stack(get_task_map(task),
1715 	    &load_result,
1716 	    p) != KERN_SUCCESS) {
1717 		error = load_return_to_errno(LOAD_NOSPACE);
1718 
1719 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1720 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1721 
1722 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1723 		if (bootarg_execfailurereports) {
1724 			set_proc_name(imgp, p);
1725 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1726 		}
1727 
1728 		goto badtoolate;
1729 	}
1730 
1731 	if (load_result.hardened_runtime_binary) {
1732 		if (cs_debug) {
1733 			printf("setting hardened runtime with entitlement mask= "
1734 			    "0x%x on task: pid = %d\n",
1735 			    load_result.hardened_runtime_binary,
1736 			    proc_getpid(p));
1737 		}
1738 		task_set_hardened_runtime(task, true);
1739 	}
1740 
1741 	/*
1742 	 * The load result will have already been munged by AMFI to include the
1743 	 * platform binary flag if boot-args dictated it (AMFI will mark anything
1744 	 * that doesn't go through the upcall path as a platform binary if its
1745 	 * enforcement is disabled).
1746 	 */
1747 	if (load_result.platform_binary) {
1748 		if (cs_debug) {
1749 			printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1750 		}
1751 
1752 		/*
1753 		 * We must use 'task' here because the proc's task has not yet been
1754 		 * switched to the new one.
1755 		 */
1756 		task_set_platform_binary(task, TRUE);
1757 	} else {
1758 		if (cs_debug) {
1759 			printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1760 		}
1761 
1762 		task_set_platform_binary(task, FALSE);
1763 	}
1764 
1765 #if XNU_TARGET_OS_OSX
1766 	/* Disable mach hardening for all 1P tasks which load 3P plugins */
1767 	if (imgp->ip_flags & IMGPF_3P_PLUGINS) {
1768 		if (cs_debug) {
1769 			printf("Disabling some mach hardening on task due to 3P plugins: pid = %d\n", proc_getpid(p));
1770 		}
1771 		task_disable_mach_hardening(task);
1772 	}
1773 #if DEVELOPMENT || DEBUG
1774 	/* Disable mach hardening for all tasks if amfi_get_out_of_my_way is set.
1775 	 * Customers will have to turn SIP off to use this boot-arg, and so this is
1776 	 * only needed internally since we disable this feature when SIP is off. */
1777 	if (AMFI_bootarg_disable_mach_hardening) {
1778 		if (cs_debug) {
1779 			printf("Disabling some mach hardening on task due to AMFI boot-args: pid = %d\n", proc_getpid(p));
1780 		}
1781 		task_disable_mach_hardening(task);
1782 	}
1783 #endif /* DEVELOPMENT || DEBUG */
1784 #endif /* XNU_TARGET_OS_OSX */
1785 
1786 	/*
1787 	 * Set starting EXC_GUARD and control port behavior for task now that
1788 	 * platform and hardened runtime is set. Use the name directly from imgp since we haven't
1789 	 * set_proc_name() yet. Also make control port for the task and main thread
1790 	 * immovable/pinned based on task's option.
1791 	 *
1792 	 * Must happen before main thread port copyout in exc_add_apple_strings.
1793 	 */
1794 	task_set_exc_guard_ctrl_port_default(task, thread,
1795 	    imgp->ip_ndp->ni_cnd.cn_nameptr,
1796 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1797 	    proc_is_simulated(p),
1798 	    load_result.ip_platform,
1799 	    load_result.lr_sdk);
1800 
1801 	error = exec_add_apple_strings(imgp, &load_result); /* copies out main thread port */
1802 
1803 	if (error) {
1804 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1805 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
1806 
1807 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
1808 		if (bootarg_execfailurereports) {
1809 			set_proc_name(imgp, p);
1810 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1811 		}
1812 		goto badtoolate;
1813 	}
1814 
1815 	/* Switch to target task's map to copy out strings */
1816 	old_map = vm_map_switch(get_task_map(task));
1817 
1818 	if (load_result.unixproc) {
1819 		user_addr_t     ap;
1820 
1821 		/*
1822 		 * Copy the strings area out into the new process address
1823 		 * space.
1824 		 */
1825 		ap = p->user_stack;
1826 		error = exec_copyout_strings(imgp, &ap);
1827 		if (error) {
1828 			vm_map_switch(old_map);
1829 
1830 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1831 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
1832 
1833 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
1834 			if (bootarg_execfailurereports) {
1835 				set_proc_name(imgp, p);
1836 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1837 			}
1838 			goto badtoolate;
1839 		}
1840 		/* Set the stack */
1841 		thread_setuserstack(thread, ap);
1842 	}
1843 
1844 	if (load_result.dynlinker || load_result.is_rosetta) {
1845 		user_addr_t        ap;
1846 		int                     new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
1847 
1848 		/* Adjust the stack */
1849 		ap = thread_adjuserstack(thread, -new_ptr_size);
1850 		error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
1851 
1852 		if (error) {
1853 			vm_map_switch(old_map);
1854 
1855 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1856 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
1857 
1858 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
1859 			if (bootarg_execfailurereports) {
1860 				set_proc_name(imgp, p);
1861 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1862 			}
1863 			goto badtoolate;
1864 		}
1865 		error = task_set_dyld_info(task, load_result.all_image_info_addr,
1866 		    load_result.all_image_info_size, false);
1867 		if (error) {
1868 			vm_map_switch(old_map);
1869 
1870 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1871 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
1872 
1873 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1874 			if (bootarg_execfailurereports) {
1875 				set_proc_name(imgp, p);
1876 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1877 			}
1878 			error = EINVAL;
1879 			goto badtoolate;
1880 		}
1881 	} else {
1882 		/*
1883 		 * No dyld or rosetta loaded, set the TF_DYLD_ALL_IMAGE_FINAL bit on task.
1884 		 */
1885 		error = task_set_dyld_info(task, MACH_VM_MIN_ADDRESS,
1886 		    0, true);
1887 		if (error) {
1888 			vm_map_switch(old_map);
1889 
1890 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1891 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
1892 
1893 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1894 			if (bootarg_execfailurereports) {
1895 				set_proc_name(imgp, p);
1896 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1897 			}
1898 			error = EINVAL;
1899 			goto badtoolate;
1900 		}
1901 	}
1902 
1903 #if CONFIG_ROSETTA
1904 	if (load_result.is_rosetta) {
1905 		// Add an fd for the executable file for Rosetta's use
1906 		int main_binary_fd;
1907 		struct fileproc *fp;
1908 
1909 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &main_binary_fd);
1910 		if (error) {
1911 			vm_map_switch(old_map);
1912 
1913 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1914 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1915 
1916 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1917 			if (bootarg_execfailurereports) {
1918 				set_proc_name(imgp, p);
1919 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1920 			}
1921 			goto badtoolate;
1922 		}
1923 
1924 		error = VNOP_OPEN(imgp->ip_vp, FREAD, imgp->ip_vfs_context);
1925 		if (error) {
1926 			vm_map_switch(old_map);
1927 
1928 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1929 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1930 
1931 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1932 			if (bootarg_execfailurereports) {
1933 				set_proc_name(imgp, p);
1934 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1935 			}
1936 			goto cleanup_rosetta_fp;
1937 		}
1938 
1939 		fp->fp_glob->fg_flag = FREAD;
1940 		fp->fp_glob->fg_ops = &vnops;
1941 		fp_set_data(fp, imgp->ip_vp);
1942 
1943 		proc_fdlock(p);
1944 		procfdtbl_releasefd(p, main_binary_fd, NULL);
1945 		fp_drop(p, main_binary_fd, fp, 1);
1946 		proc_fdunlock(p);
1947 
1948 		vnode_ref(imgp->ip_vp);
1949 
1950 		// Pass the dyld load address, main binary fd, and dyld fd on the stack
1951 		uint64_t ap = thread_adjuserstack(thread, -24);
1952 
1953 		error = copyoutptr((user_addr_t)load_result.dynlinker_fd, ap, 8);
1954 		if (error) {
1955 			vm_map_switch(old_map);
1956 
1957 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1958 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1959 
1960 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1961 			if (bootarg_execfailurereports) {
1962 				set_proc_name(imgp, p);
1963 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1964 			}
1965 			goto cleanup_rosetta_fp;
1966 		}
1967 
1968 		error = copyoutptr(load_result.dynlinker_mach_header, ap + 8, 8);
1969 		if (error) {
1970 			vm_map_switch(old_map);
1971 
1972 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1973 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1974 
1975 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1976 			if (bootarg_execfailurereports) {
1977 				set_proc_name(imgp, p);
1978 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1979 			}
1980 			goto cleanup_rosetta_fp;
1981 		}
1982 
1983 		error = copyoutptr((user_addr_t)main_binary_fd, ap + 16, 8);
1984 		if (error) {
1985 			vm_map_switch(old_map);
1986 
1987 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1988 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1989 
1990 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1991 			if (bootarg_execfailurereports) {
1992 				set_proc_name(imgp, p);
1993 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1994 			}
1995 			goto cleanup_rosetta_fp;
1996 		}
1997 
1998 cleanup_rosetta_fp:
1999 		if (error) {
2000 			fp_free(p, load_result.dynlinker_fd, load_result.dynlinker_fp);
2001 			fp_free(p, main_binary_fd, fp);
2002 			goto badtoolate;
2003 		}
2004 	}
2005 
2006 #endif
2007 
2008 	/* Avoid immediate VM faults back into kernel */
2009 	exec_prefault_data(p, imgp, &load_result);
2010 
2011 	vm_map_switch(old_map);
2012 
2013 	/*
2014 	 * Reset signal state.
2015 	 */
2016 	execsigs(p, thread);
2017 
2018 	/*
2019 	 * need to cancel async IO requests that can be cancelled and wait for those
2020 	 * already active.  MAY BLOCK!
2021 	 */
2022 	_aio_exec( p );
2023 
2024 #if SYSV_SHM
2025 	/* FIXME: Till vmspace inherit is fixed: */
2026 	if (!vfexec && p->vm_shm) {
2027 		shmexec(p);
2028 	}
2029 #endif
2030 #if SYSV_SEM
2031 	/* Clean up the semaphores */
2032 	semexit(p);
2033 #endif
2034 
2035 	/*
2036 	 * Remember file name for accounting.
2037 	 */
2038 	p->p_acflag &= ~AFORK;
2039 
2040 	set_proc_name(imgp, p);
2041 
2042 #if CONFIG_SECLUDED_MEMORY
2043 	if (secluded_for_apps &&
2044 	    load_result.platform_binary) {
2045 		if (strncmp(p->p_name,
2046 		    "Camera",
2047 		    sizeof(p->p_name)) == 0) {
2048 			task_set_could_use_secluded_mem(task, TRUE);
2049 		} else {
2050 			task_set_could_use_secluded_mem(task, FALSE);
2051 		}
2052 		if (strncmp(p->p_name,
2053 		    "mediaserverd",
2054 		    sizeof(p->p_name)) == 0) {
2055 			task_set_could_also_use_secluded_mem(task, TRUE);
2056 		}
2057 		if (strncmp(p->p_name,
2058 		    "cameracaptured",
2059 		    sizeof(p->p_name)) == 0) {
2060 			task_set_could_also_use_secluded_mem(task, TRUE);
2061 		}
2062 	}
2063 #endif /* CONFIG_SECLUDED_MEMORY */
2064 
2065 #if __arm64__
2066 	if (load_result.legacy_footprint) {
2067 		task_set_legacy_footprint(task);
2068 	}
2069 #endif /* __arm64__ */
2070 
2071 	pal_dbg_set_task_name(task);
2072 
2073 #if DEVELOPMENT || DEBUG
2074 	/*
2075 	 * Update the pid an proc name for importance base if any
2076 	 */
2077 	task_importance_update_owner_info(task);
2078 #endif
2079 
2080 	proc_setexecutableuuid(p, &load_result.uuid[0]);
2081 
2082 #if CONFIG_DTRACE
2083 	dtrace_proc_exec(p);
2084 #endif
2085 
2086 
2087 	if (kdebug_enable) {
2088 		long args[4] = {};
2089 
2090 		uintptr_t fsid = 0, fileid = 0;
2091 		if (imgp->ip_vattr) {
2092 			uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
2093 			fsid   = (uintptr_t)fsid64;
2094 			fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
2095 			// check for (unexpected) overflow and trace zero in that case
2096 			if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
2097 				fsid = fileid = 0;
2098 			}
2099 		}
2100 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
2101 		    (uintptr_t)thread_tid(thread));
2102 
2103 		extern void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
2104 		kdebug_proc_name_args(p, args);
2105 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
2106 		    args[2], args[3], (uintptr_t)thread_tid(thread));
2107 	}
2108 
2109 
2110 	/*
2111 	 * If posix_spawned with the START_SUSPENDED flag, stop the
2112 	 * process before it runs.
2113 	 */
2114 	if (imgp->ip_px_sa != NULL) {
2115 		psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
2116 		if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
2117 			proc_lock(p);
2118 			p->p_stat = SSTOP;
2119 			proc_unlock(p);
2120 			(void) task_suspend_internal(task);
2121 		}
2122 	}
2123 
2124 	/*
2125 	 * mark as execed
2126 	 */
2127 	OSBitOrAtomic(P_EXEC, &p->p_flag);
2128 	proc_resetregister(p);
2129 	if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
2130 		proc_lock(p);
2131 		p->p_lflag &= ~P_LPPWAIT;
2132 		proc_unlock(p);
2133 		wakeup((caddr_t)p->p_pptr);
2134 	}
2135 
2136 	/*
2137 	 * Set up dext coredumps on kernel panic.
2138 	 * This requires the following:
2139 	 * - dext_panic_coredump=1 boot-arg (enabled by default on DEVELOPMENT, DEBUG and certain Seed builds)
2140 	 * - process must be a driver
2141 	 * - process must have the com.apple.private.enable-coredump-on-panic entitlement, and the
2142 	 *   entitlement has a string value.
2143 	 * - process must have the com.apple.private.enable-coredump-on-panic-seed-privacy-approved
2144 	 *   entitlement (Seed builds only).
2145 	 *
2146 	 * The core dump file name is formatted with the entitlement string value, followed by a hyphen
2147 	 * and the process PID.
2148 	 */
2149 	if (enable_dext_coredumps_on_panic &&
2150 	    (imgp->ip_flags & IMGPF_DRIVER) != 0 &&
2151 	    (userspace_coredump_name = IOVnodeGetEntitlement(imgp->ip_vp,
2152 	    (int64_t)imgp->ip_arch_offset, USERSPACE_COREDUMP_PANIC_ENTITLEMENT)) != NULL) {
2153 		size_t userspace_coredump_name_len = strlen(userspace_coredump_name);
2154 
2155 		char core_name[MACH_CORE_FILEHEADER_NAMELEN];
2156 		/* 16 - NULL char - strlen("-") - maximum of 5 digits for pid */
2157 		snprintf(core_name, MACH_CORE_FILEHEADER_NAMELEN, "%.9s-%d", userspace_coredump_name, proc_getpid(p));
2158 
2159 		kern_register_userspace_coredump(task, core_name);
2160 
2161 		/* Discard the copy of the entitlement */
2162 		kfree_data(userspace_coredump_name, userspace_coredump_name_len + 1);
2163 		userspace_coredump_name = NULL;
2164 	}
2165 
2166 	goto done;
2167 
2168 badtoolate:
2169 	/* Don't allow child process to execute any instructions */
2170 	if (!spawn) {
2171 		{
2172 			assert(exec_failure_reason != OS_REASON_NULL);
2173 			if (bootarg_execfailurereports) {
2174 				set_proc_name(imgp, current_proc());
2175 			}
2176 			psignal_with_reason(current_proc(), SIGKILL, exec_failure_reason);
2177 			exec_failure_reason = OS_REASON_NULL;
2178 
2179 			if (exec) {
2180 				/* Terminate the exec copy task */
2181 				task_terminate_internal(task);
2182 			}
2183 		}
2184 
2185 		/* We can't stop this system call at this point, so just pretend we succeeded */
2186 		error = 0;
2187 	} else {
2188 		os_reason_free(exec_failure_reason);
2189 		exec_failure_reason = OS_REASON_NULL;
2190 	}
2191 
2192 done:
2193 	if (load_result.threadstate) {
2194 		kfree_data(load_result.threadstate, load_result.threadstate_sz);
2195 		load_result.threadstate = NULL;
2196 	}
2197 
2198 bad:
2199 	/* If we hit this, we likely would have leaked an exit reason */
2200 	assert(exec_failure_reason == OS_REASON_NULL);
2201 	return error;
2202 }
2203 
2204 
2205 
2206 
2207 /*
2208  * Our image activator table; this is the table of the image types we are
2209  * capable of loading.  We list them in order of preference to ensure the
2210  * fastest image load speed.
2211  *
2212  * XXX hardcoded, for now; should use linker sets
2213  */
2214 struct execsw {
2215 	int(*const ex_imgact)(struct image_params *);
2216 	const char *ex_name;
2217 }const execsw[] = {
2218 	{ exec_mach_imgact, "Mach-o Binary" },
2219 	{ exec_fat_imgact, "Fat Binary" },
2220 	{ exec_shell_imgact, "Interpreter Script" },
2221 	{ NULL, NULL}
2222 };
2223 
2224 
2225 /*
2226  * exec_activate_image
2227  *
2228  * Description:	Iterate through the available image activators, and activate
2229  *		the image associated with the imgp structure.  We start with
2230  *		the activator for Mach-o binaries followed by that for Fat binaries
2231  *		for Interpreter scripts.
2232  *
2233  * Parameters:	struct image_params *	Image parameter block
2234  *
2235  * Returns:	0			Success
2236  *		ENOEXEC			No activator for image.
2237  *		EBADEXEC		The executable is corrupt/unknown
2238  *	execargs_alloc:EINVAL		Invalid argument
2239  *	execargs_alloc:EACCES		Permission denied
2240  *	execargs_alloc:EINTR		Interrupted function
2241  *	execargs_alloc:ENOMEM		Not enough space
2242  *	exec_save_path:EFAULT		Bad address
2243  *	exec_save_path:ENAMETOOLONG	Filename too long
2244  *	exec_check_permissions:EACCES	Permission denied
2245  *	exec_check_permissions:ENOEXEC	Executable file format error
2246  *	exec_check_permissions:ETXTBSY	Text file busy [misuse of error code]
2247  *	exec_check_permissions:???
2248  *	namei:???
2249  *	vn_rdwr:???			[anything vn_rdwr can return]
2250  *	<ex_imgact>:???			[anything an imgact can return]
2251  *	EDEADLK				Process is being terminated
2252  */
2253 static int
exec_activate_image(struct image_params * imgp)2254 exec_activate_image(struct image_params *imgp)
2255 {
2256 	struct nameidata *ndp = NULL;
2257 	const char *excpath;
2258 	int error;
2259 	int resid;
2260 	int once = 1;   /* save SGUID-ness for interpreted files */
2261 	int i;
2262 	int itercount = 0;
2263 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2264 
2265 	/*
2266 	 * For exec, the translock needs to be taken on old proc and not
2267 	 * on new shadow proc.
2268 	 */
2269 	if (imgp->ip_flags & IMGPF_EXEC) {
2270 		p = current_proc();
2271 	}
2272 
2273 	error = execargs_alloc(imgp);
2274 	if (error) {
2275 		goto bad_notrans;
2276 	}
2277 
2278 	error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
2279 	if (error) {
2280 		goto bad_notrans;
2281 	}
2282 
2283 	/* Use excpath, which contains the copyin-ed exec path */
2284 	DTRACE_PROC1(exec, uintptr_t, excpath);
2285 
2286 	ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2287 
2288 	NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
2289 	    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2290 
2291 again:
2292 	error = namei(ndp);
2293 	if (error) {
2294 		if (error == ERESTART) {
2295 			error = EINTR;
2296 		}
2297 		goto bad_notrans;
2298 	}
2299 	imgp->ip_ndp = ndp;     /* successful namei(); call nameidone() later */
2300 	imgp->ip_vp = ndp->ni_vp;       /* if set, need to vnode_put() at some point */
2301 
2302 	/*
2303 	 * Before we start the transition from binary A to binary B, make
2304 	 * sure another thread hasn't started exiting the process.  We grab
2305 	 * the proc lock to check p_lflag initially, and the transition
2306 	 * mechanism ensures that the value doesn't change after we release
2307 	 * the lock.
2308 	 */
2309 	proc_lock(p);
2310 	if (p->p_lflag & P_LEXIT) {
2311 		error = EDEADLK;
2312 		proc_unlock(p);
2313 		goto bad_notrans;
2314 	}
2315 	error = proc_transstart(p, 1, 0);
2316 	proc_unlock(p);
2317 	if (error) {
2318 		goto bad_notrans;
2319 	}
2320 
2321 	error = exec_check_permissions(imgp);
2322 	if (error) {
2323 		goto bad;
2324 	}
2325 
2326 	/* Copy; avoid invocation of an interpreter overwriting the original */
2327 	if (once) {
2328 		once = 0;
2329 		*imgp->ip_origvattr = *imgp->ip_vattr;
2330 	}
2331 
2332 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
2333 	    UIO_SYSSPACE, IO_NODELOCKED,
2334 	    vfs_context_ucred(imgp->ip_vfs_context),
2335 	    &resid, vfs_context_proc(imgp->ip_vfs_context));
2336 	if (error) {
2337 		goto bad;
2338 	}
2339 
2340 	if (resid) {
2341 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
2342 	}
2343 
2344 encapsulated_binary:
2345 	/* Limit the number of iterations we will attempt on each binary */
2346 	if (++itercount > EAI_ITERLIMIT) {
2347 		error = EBADEXEC;
2348 		goto bad;
2349 	}
2350 	error = -1;
2351 	for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
2352 		error = (*execsw[i].ex_imgact)(imgp);
2353 
2354 		switch (error) {
2355 		/* case -1: not claimed: continue */
2356 		case -2:                /* Encapsulated binary, imgp->ip_XXX set for next iteration */
2357 			goto encapsulated_binary;
2358 
2359 		case -3:                /* Interpreter */
2360 #if CONFIG_MACF
2361 			/*
2362 			 * Copy the script label for later use. Note that
2363 			 * the label can be different when the script is
2364 			 * actually read by the interpreter.
2365 			 */
2366 			if (imgp->ip_scriptlabelp) {
2367 				mac_vnode_label_free(imgp->ip_scriptlabelp);
2368 				imgp->ip_scriptlabelp = NULL;
2369 			}
2370 			imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
2371 			if (imgp->ip_scriptlabelp == NULL) {
2372 				error = ENOMEM;
2373 				break;
2374 			}
2375 			mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
2376 			    imgp->ip_scriptlabelp);
2377 
2378 			/*
2379 			 * Take a ref of the script vnode for later use.
2380 			 */
2381 			if (imgp->ip_scriptvp) {
2382 				vnode_put(imgp->ip_scriptvp);
2383 				imgp->ip_scriptvp = NULLVP;
2384 			}
2385 			if (vnode_getwithref(imgp->ip_vp) == 0) {
2386 				imgp->ip_scriptvp = imgp->ip_vp;
2387 			}
2388 #endif
2389 
2390 			nameidone(ndp);
2391 
2392 			vnode_put(imgp->ip_vp);
2393 			imgp->ip_vp = NULL;     /* already put */
2394 			imgp->ip_ndp = NULL; /* already nameidone */
2395 
2396 			/* Use excpath, which exec_shell_imgact reset to the interpreter */
2397 			NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
2398 			    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2399 
2400 			proc_transend(p, 0);
2401 			goto again;
2402 
2403 		default:
2404 			break;
2405 		}
2406 	}
2407 
2408 	if (error == -1) {
2409 		error = ENOEXEC;
2410 	} else if (error == 0) {
2411 		if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
2412 			AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
2413 		}
2414 
2415 		/*
2416 		 * Call out to allow 3rd party notification of exec.
2417 		 * Ignore result of kauth_authorize_fileop call.
2418 		 */
2419 		if (kauth_authorize_fileop_has_listeners()) {
2420 			kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
2421 			    KAUTH_FILEOP_EXEC,
2422 			    (uintptr_t)ndp->ni_vp, 0);
2423 		}
2424 	}
2425 bad:
2426 	proc_transend(p, 0);
2427 
2428 bad_notrans:
2429 	if (imgp->ip_strings) {
2430 		execargs_free(imgp);
2431 	}
2432 	if (imgp->ip_ndp) {
2433 		nameidone(imgp->ip_ndp);
2434 	}
2435 	kfree_type(struct nameidata, ndp);
2436 
2437 	return error;
2438 }
2439 
2440 /*
2441  * exec_validate_spawnattr_policy
2442  *
2443  * Description: Validates the entitlements required to set the apptype.
2444  *
2445  * Parameters:  int psa_apptype         posix spawn attribute apptype
2446  *
2447  * Returns:     0                       Success
2448  *              EPERM                   Failure
2449  */
2450 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)2451 exec_validate_spawnattr_policy(int psa_apptype)
2452 {
2453 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2454 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2455 		if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
2456 			if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
2457 				return EPERM;
2458 			}
2459 		}
2460 	}
2461 
2462 	return 0;
2463 }
2464 
2465 /*
2466  * exec_handle_spawnattr_policy
2467  *
2468  * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
2469  *
2470  * Parameters:  proc_t p                process to apply attributes to
2471  *              int psa_apptype         posix spawn attribute apptype
2472  *
2473  * Returns:     0                       Success
2474  */
2475 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)2476 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2477     task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2478 {
2479 	int apptype     = TASK_APPTYPE_NONE;
2480 	int qos_clamp   = THREAD_QOS_UNSPECIFIED;
2481 	task_role_t role = TASK_UNSPECIFIED;
2482 
2483 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2484 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2485 
2486 		switch (proctype) {
2487 		case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2488 			apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2489 			break;
2490 		case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2491 			apptype = TASK_APPTYPE_DAEMON_STANDARD;
2492 			break;
2493 		case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2494 			apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2495 			break;
2496 		case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2497 			apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2498 			break;
2499 		case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2500 			apptype = TASK_APPTYPE_APP_DEFAULT;
2501 			break;
2502 		case POSIX_SPAWN_PROC_TYPE_DRIVER:
2503 			apptype = TASK_APPTYPE_DRIVER;
2504 			break;
2505 		default:
2506 			apptype = TASK_APPTYPE_NONE;
2507 			/* TODO: Should an invalid value here fail the spawn? */
2508 			break;
2509 		}
2510 	}
2511 
2512 	if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2513 		switch (psa_qos_clamp) {
2514 		case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2515 			qos_clamp = THREAD_QOS_UTILITY;
2516 			break;
2517 		case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2518 			qos_clamp = THREAD_QOS_BACKGROUND;
2519 			break;
2520 		case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2521 			qos_clamp = THREAD_QOS_MAINTENANCE;
2522 			break;
2523 		default:
2524 			qos_clamp = THREAD_QOS_UNSPECIFIED;
2525 			/* TODO: Should an invalid value here fail the spawn? */
2526 			break;
2527 		}
2528 	}
2529 
2530 	if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2531 		proc_darwin_role_to_task_role(psa_darwin_role, &role);
2532 	}
2533 
2534 	if (apptype != TASK_APPTYPE_NONE ||
2535 	    qos_clamp != THREAD_QOS_UNSPECIFIED ||
2536 	    role != TASK_UNSPECIFIED ||
2537 	    port_actions->portwatch_count) {
2538 		proc_set_task_spawnpolicy(proc_task(p), thread, apptype, qos_clamp, role,
2539 		    port_actions->portwatch_array, port_actions->portwatch_count);
2540 	}
2541 
2542 	if (port_actions->registered_count) {
2543 		if (_kernelrpc_mach_ports_register3(proc_task(p),
2544 		    port_actions->registered_array[0],
2545 		    port_actions->registered_array[1],
2546 		    port_actions->registered_array[2])) {
2547 			return EINVAL;
2548 		}
2549 		/* mach_ports_register() consumed the array */
2550 		bzero(port_actions->registered_array,
2551 		    sizeof(port_actions->registered_array));
2552 		port_actions->registered_count = 0;
2553 	}
2554 
2555 	return 0;
2556 }
2557 
2558 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2559 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2560 {
2561 	if (port_actions->excport_array) {
2562 		for (uint32_t i = 0; i < port_actions->exception_port_count; i++) {
2563 			ipc_port_t port = NULL;
2564 			if ((port = port_actions->excport_array[i].port) != NULL) {
2565 				ipc_port_release_send(port);
2566 			}
2567 		}
2568 		kfree_type(struct exception_port_action_t, port_actions->exception_port_count,
2569 		    port_actions->excport_array);
2570 	}
2571 
2572 	if (port_actions->portwatch_array) {
2573 		for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2574 			ipc_port_t port = NULL;
2575 			if ((port = port_actions->portwatch_array[i]) != NULL) {
2576 				ipc_port_release_send(port);
2577 			}
2578 		}
2579 		kfree_type(ipc_port_t, port_actions->portwatch_count,
2580 		    port_actions->portwatch_array);
2581 	}
2582 
2583 	for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2584 		ipc_port_t port = NULL;
2585 		if ((port = port_actions->registered_array[i]) != NULL) {
2586 			ipc_port_release_send(port);
2587 		}
2588 	}
2589 }
2590 
2591 /*
2592  * exec_handle_port_actions
2593  *
2594  * Description:	Go through the _posix_port_actions_t contents,
2595  *              calling task_set_special_port, task_set_exception_ports
2596  *              and/or audit_session_spawnjoin for the current task.
2597  *
2598  * Parameters:	struct image_params *	Image parameter block
2599  *
2600  * Returns:	0			Success
2601  *              EINVAL			Failure
2602  *              ENOTSUP			Illegal posix_spawn attr flag was set
2603  */
2604 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2605 exec_handle_port_actions(struct image_params *imgp,
2606     struct exec_port_actions *actions)
2607 {
2608 	_posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2609 #if CONFIG_AUDIT
2610 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2611 #endif
2612 	_ps_port_action_t *act = NULL;
2613 	task_t task = get_threadtask(imgp->ip_new_thread);
2614 	ipc_port_t port = NULL;
2615 	errno_t ret = 0;
2616 	int i = 0, portwatch_i = 0, registered_i = 0, excport_i = 0;
2617 	kern_return_t kr;
2618 	boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2619 	boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2620 	int ptrauth_task_port_count = 0;
2621 
2622 	for (i = 0; i < pacts->pspa_count; i++) {
2623 		act = &pacts->pspa_actions[i];
2624 
2625 		switch (act->port_type) {
2626 		case PSPA_SPECIAL:
2627 #if CONFIG_AUDIT
2628 		case PSPA_AU_SESSION:
2629 #endif
2630 			break;
2631 		case PSPA_EXCEPTION:
2632 			if (++actions->exception_port_count > TASK_MAX_EXCEPTION_PORT_COUNT) {
2633 				ret = EINVAL;
2634 				goto done;
2635 			}
2636 			break;
2637 		case PSPA_IMP_WATCHPORTS:
2638 			if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
2639 				ret = EINVAL;
2640 				goto done;
2641 			}
2642 			break;
2643 		case PSPA_REGISTERED_PORTS:
2644 			if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
2645 				ret = EINVAL;
2646 				goto done;
2647 			}
2648 			break;
2649 		case PSPA_PTRAUTH_TASK_PORT:
2650 			if (++ptrauth_task_port_count > 1) {
2651 				ret = EINVAL;
2652 				goto done;
2653 			}
2654 			break;
2655 		default:
2656 			ret = EINVAL;
2657 			goto done;
2658 		}
2659 	}
2660 
2661 	if (actions->exception_port_count) {
2662 		actions->excport_array = kalloc_type(struct exception_port_action_t,
2663 		    actions->exception_port_count, Z_WAITOK | Z_ZERO);
2664 
2665 		if (actions->excport_array == NULL) {
2666 			ret = ENOMEM;
2667 			goto done;
2668 		}
2669 	}
2670 	if (actions->portwatch_count) {
2671 		if (in_exec && task_has_watchport_boost) {
2672 			ret = EINVAL;
2673 			goto done;
2674 		}
2675 		actions->portwatch_array = kalloc_type(ipc_port_t,
2676 		    actions->portwatch_count, Z_WAITOK | Z_ZERO);
2677 		if (actions->portwatch_array == NULL) {
2678 			ret = ENOMEM;
2679 			goto done;
2680 		}
2681 	}
2682 
2683 	for (i = 0; i < pacts->pspa_count; i++) {
2684 		act = &pacts->pspa_actions[i];
2685 
2686 		if (MACH_PORT_VALID(act->new_port)) {
2687 			kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2688 			    act->new_port, MACH_MSG_TYPE_COPY_SEND,
2689 			    (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2690 
2691 			if (kr != KERN_SUCCESS) {
2692 				ret = EINVAL;
2693 				goto done;
2694 			}
2695 		} else {
2696 			/* it's NULL or DEAD */
2697 			port = CAST_MACH_NAME_TO_PORT(act->new_port);
2698 		}
2699 
2700 		switch (act->port_type) {
2701 		case PSPA_SPECIAL:
2702 			kr = task_set_special_port(task, act->which, port);
2703 
2704 			if (kr != KERN_SUCCESS) {
2705 				ret = EINVAL;
2706 			}
2707 			break;
2708 
2709 #if CONFIG_AUDIT
2710 		case PSPA_AU_SESSION:
2711 			ret = audit_session_spawnjoin(p, port);
2712 			if (ret) {
2713 				/* audit_session_spawnjoin() has already dropped the reference in case of error. */
2714 				goto done;
2715 			}
2716 
2717 			break;
2718 #endif
2719 		case PSPA_EXCEPTION:
2720 			assert(excport_i < actions->exception_port_count);
2721 			/* hold on to this till end of spawn */
2722 			actions->excport_array[excport_i].port_action = act;
2723 			actions->excport_array[excport_i].port = port;
2724 			excport_i++;
2725 			break;
2726 		case PSPA_IMP_WATCHPORTS:
2727 			assert(portwatch_i < actions->portwatch_count);
2728 			/* hold on to this till end of spawn */
2729 			actions->portwatch_array[portwatch_i++] = port;
2730 			break;
2731 		case PSPA_REGISTERED_PORTS:
2732 			assert(registered_i < actions->registered_count);
2733 			/* hold on to this till end of spawn */
2734 			actions->registered_array[registered_i++] = port;
2735 			break;
2736 
2737 		case PSPA_PTRAUTH_TASK_PORT:
2738 #if (DEVELOPMENT || DEBUG)
2739 #if defined(HAS_APPLE_PAC)
2740 			{
2741 				task_t ptr_auth_task = convert_port_to_task(port);
2742 
2743 				if (ptr_auth_task == TASK_NULL) {
2744 					ret = EINVAL;
2745 					break;
2746 				}
2747 
2748 				imgp->ip_inherited_shared_region_id =
2749 				    task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
2750 				    &imgp->ip_inherited_jop_pid);
2751 
2752 				/* Deallocate task ref returned by convert_port_to_task */
2753 				task_deallocate(ptr_auth_task);
2754 			}
2755 #endif /* HAS_APPLE_PAC */
2756 #endif /* (DEVELOPMENT || DEBUG) */
2757 
2758 			/* consume the port right in case of success */
2759 			ipc_port_release_send(port);
2760 			break;
2761 		default:
2762 			ret = EINVAL;
2763 			break;
2764 		}
2765 
2766 		if (ret) {
2767 			/* action failed, so release port resources */
2768 			ipc_port_release_send(port);
2769 			break;
2770 		}
2771 	}
2772 
2773 done:
2774 	if (0 != ret) {
2775 		DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2776 	}
2777 	return ret;
2778 }
2779 
2780 
2781 /*
2782  * exec_handle_exception_port_actions
2783  *
2784  * Description:	Go through the saved exception ports in exec_port_actions,
2785  *              calling task_set_exception_ports for the current Task.
2786  *              This must happen after image activation, and after exec_resettextvp()
2787  *				because task_set_exception_ports checks the `TF_PLATFORM` bit and entitlements.
2788  *
2789  * Parameters:	struct image_params *		Image parameter block
2790  *                              struct exec_port_actions *  Saved Port Actions
2791  *
2792  * Returns:	0			Success
2793  *              EINVAL			task_set_exception_ports failed
2794  */
2795 static errno_t
exec_handle_exception_port_actions(const struct image_params * imgp,const struct exec_port_actions * actions)2796 exec_handle_exception_port_actions(const struct image_params *imgp,
2797     const struct exec_port_actions *actions)
2798 {
2799 	task_t task = get_threadtask(imgp->ip_new_thread);
2800 
2801 	for (int i = 0; i < actions->exception_port_count; i++) {
2802 		ipc_port_t port = actions->excport_array[i].port;
2803 		_ps_port_action_t *act = actions->excport_array[i].port_action;
2804 		assert(act != NULL);
2805 		kern_return_t kr = task_set_exception_ports(task, act->mask, port,
2806 		    act->behavior, act->flavor);
2807 		if (kr != KERN_SUCCESS) {
2808 			DTRACE_PROC1(spawn__exception__port__failure, mach_port_name_t, act->new_port);
2809 			return EINVAL;
2810 		}
2811 		actions->excport_array[i].port = NULL;
2812 	}
2813 
2814 	return 0;
2815 }
2816 
2817 
2818 /*
2819  * exec_handle_file_actions
2820  *
2821  * Description:	Go through the _posix_file_actions_t contents applying the
2822  *		open, close, and dup2 operations to the open file table for
2823  *		the current process.
2824  *
2825  * Parameters:	struct image_params *	Image parameter block
2826  *
2827  * Returns:	0			Success
2828  *		???
2829  *
2830  * Note:	Actions are applied in the order specified, with the credential
2831  *		of the parent process.  This is done to permit the parent
2832  *		process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
2833  *		the child following operations the child may in fact not be
2834  *		normally permitted to perform.
2835  */
2836 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)2837 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
2838 {
2839 	int error = 0;
2840 	int action;
2841 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2842 	kauth_cred_t p_cred = vfs_context_ucred(imgp->ip_vfs_context);
2843 	_posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
2844 	int ival[2];            /* dummy retval for system calls) */
2845 #if CONFIG_AUDIT
2846 	struct uthread *uthread = current_uthread();
2847 #endif
2848 
2849 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
2850 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2851 
2852 		switch (psfa->psfaa_type) {
2853 		case PSFA_OPEN: {
2854 			/*
2855 			 * Open is different, in that it requires the use of
2856 			 * a path argument, which is normally copied in from
2857 			 * user space; because of this, we have to support an
2858 			 * open from kernel space that passes an address space
2859 			 * context of UIO_SYSSPACE, and casts the address
2860 			 * argument to a user_addr_t.
2861 			 */
2862 			struct vnode_attr *vap;
2863 			struct nameidata *ndp;
2864 			int mode = psfa->psfaa_openargs.psfao_mode;
2865 			int origfd;
2866 			struct {
2867 				struct vnode_attr va;
2868 				struct nameidata nd;
2869 			} *__open_data;
2870 
2871 			__open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
2872 			if (__open_data == NULL) {
2873 				error = ENOMEM;
2874 				break;
2875 			}
2876 
2877 			vap = &__open_data->va;
2878 			ndp = &__open_data->nd;
2879 
2880 			VATTR_INIT(vap);
2881 			/* Mask off all but regular access permissions */
2882 			mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
2883 			VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
2884 
2885 			AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
2886 
2887 			NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2888 			    CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
2889 			    imgp->ip_vfs_context);
2890 
2891 			error = open1(imgp->ip_vfs_context, ndp,
2892 			    psfa->psfaa_openargs.psfao_oflag,
2893 			    vap, NULL, NULL, &origfd, AUTH_OPEN_NOAUTHFD);
2894 
2895 			kfree_type(typeof(*__open_data), __open_data);
2896 
2897 			AUDIT_SUBCALL_EXIT(uthread, error);
2898 
2899 			/*
2900 			 * If there's an error, or we get the right fd by
2901 			 * accident, then drop out here.  This is easier than
2902 			 * reworking all the open code to preallocate fd
2903 			 * slots, and internally taking one as an argument.
2904 			 */
2905 			if (error || origfd == psfa->psfaa_filedes) {
2906 				break;
2907 			}
2908 
2909 			/*
2910 			 * If we didn't fall out from an error, we ended up
2911 			 * with the wrong fd; so now we've got to try to dup2
2912 			 * it to the right one.
2913 			 */
2914 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2915 			error = dup2(p, p_cred, origfd, psfa->psfaa_filedes, ival);
2916 			AUDIT_SUBCALL_EXIT(uthread, error);
2917 			if (error) {
2918 				break;
2919 			}
2920 
2921 			/*
2922 			 * Finally, close the original fd.
2923 			 */
2924 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2925 			error = close_nocancel(p, p_cred, origfd);
2926 			AUDIT_SUBCALL_EXIT(uthread, error);
2927 		}
2928 		break;
2929 
2930 		case PSFA_DUP2: {
2931 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2932 			error = dup2(p, p_cred, psfa->psfaa_filedes,
2933 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2934 			AUDIT_SUBCALL_EXIT(uthread, error);
2935 		}
2936 		break;
2937 
2938 		case PSFA_FILEPORT_DUP2: {
2939 			ipc_port_t port;
2940 			kern_return_t kr;
2941 			int origfd;
2942 
2943 			if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
2944 				error = EINVAL;
2945 				break;
2946 			}
2947 
2948 			kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2949 			    psfa->psfaa_fileport, MACH_MSG_TYPE_COPY_SEND,
2950 			    (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2951 
2952 			if (kr != KERN_SUCCESS) {
2953 				error = EINVAL;
2954 				break;
2955 			}
2956 
2957 			error = fileport_makefd(p, port, 0, &origfd);
2958 
2959 			if (IPC_PORT_NULL != port) {
2960 				ipc_port_release_send(port);
2961 			}
2962 
2963 			if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
2964 				break;
2965 			}
2966 
2967 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2968 			error = dup2(p, p_cred, origfd,
2969 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2970 			AUDIT_SUBCALL_EXIT(uthread, error);
2971 			if (error) {
2972 				break;
2973 			}
2974 
2975 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2976 			error = close_nocancel(p, p_cred, origfd);
2977 			AUDIT_SUBCALL_EXIT(uthread, error);
2978 		}
2979 		break;
2980 
2981 		case PSFA_CLOSE: {
2982 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2983 			error = close_nocancel(p, p_cred, psfa->psfaa_filedes);
2984 			AUDIT_SUBCALL_EXIT(uthread, error);
2985 		}
2986 		break;
2987 
2988 		case PSFA_INHERIT: {
2989 			struct fileproc *fp;
2990 
2991 			/*
2992 			 * Check to see if the descriptor exists, and
2993 			 * ensure it's -not- marked as close-on-exec.
2994 			 *
2995 			 * Attempting to "inherit" a guarded fd will
2996 			 * result in a error.
2997 			 */
2998 
2999 			proc_fdlock(p);
3000 			if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
3001 				error = EBADF;
3002 			} else if (fp->fp_guard_attrs) {
3003 				error = fp_guard_exception(p, psfa->psfaa_filedes,
3004 				    fp, kGUARD_EXC_NOCLOEXEC);
3005 			} else {
3006 				fp->fp_flags &= ~FP_CLOEXEC;
3007 				error = 0;
3008 			}
3009 			proc_fdunlock(p);
3010 		}
3011 		break;
3012 
3013 		case PSFA_CHDIR: {
3014 			/*
3015 			 * Chdir is different, in that it requires the use of
3016 			 * a path argument, which is normally copied in from
3017 			 * user space; because of this, we have to support a
3018 			 * chdir from kernel space that passes an address space
3019 			 * context of UIO_SYSSPACE, and casts the address
3020 			 * argument to a user_addr_t.
3021 			 */
3022 			struct nameidata *nd;
3023 			nd = kalloc_type(struct nameidata,
3024 			    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3025 
3026 			AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
3027 			NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
3028 			    CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
3029 			    imgp->ip_vfs_context);
3030 
3031 			error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
3032 			kfree_type(struct nameidata, nd);
3033 			AUDIT_SUBCALL_EXIT(uthread, error);
3034 		}
3035 		break;
3036 
3037 		case PSFA_FCHDIR: {
3038 			AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
3039 			error = fchdir(p, imgp->ip_vfs_context,
3040 			    psfa->psfaa_filedes, false);
3041 			AUDIT_SUBCALL_EXIT(uthread, error);
3042 		}
3043 		break;
3044 
3045 		default:
3046 			error = EINVAL;
3047 			break;
3048 		}
3049 
3050 		/* All file actions failures are considered fatal, per POSIX */
3051 
3052 		if (error) {
3053 			if (PSFA_OPEN == psfa->psfaa_type) {
3054 				DTRACE_PROC1(spawn__open__failure, uintptr_t,
3055 				    psfa->psfaa_openargs.psfao_path);
3056 			} else {
3057 				DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
3058 			}
3059 			break;
3060 		}
3061 	}
3062 
3063 	if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
3064 		return error;
3065 	}
3066 
3067 	/*
3068 	 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
3069 	 * this spawn only) as if "close on exec" is the default
3070 	 * disposition of all pre-existing file descriptors.  In this case,
3071 	 * the list of file descriptors mentioned in the file actions
3072 	 * are the only ones that can be inherited, so mark them now.
3073 	 *
3074 	 * The actual closing part comes later, in fdt_exec().
3075 	 */
3076 	proc_fdlock(p);
3077 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
3078 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3079 		int fd = psfa->psfaa_filedes;
3080 
3081 		switch (psfa->psfaa_type) {
3082 		case PSFA_DUP2:
3083 		case PSFA_FILEPORT_DUP2:
3084 			fd = psfa->psfaa_dup2args.psfad_newfiledes;
3085 			OS_FALLTHROUGH;
3086 		case PSFA_OPEN:
3087 		case PSFA_INHERIT:
3088 			*fdflags(p, fd) |= UF_INHERIT;
3089 			break;
3090 
3091 		case PSFA_CLOSE:
3092 		case PSFA_CHDIR:
3093 		case PSFA_FCHDIR:
3094 			/*
3095 			 * Although PSFA_FCHDIR does have a file descriptor, it is not
3096 			 * *creating* one, thus we do not automatically mark it for
3097 			 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
3098 			 * wishes it to be inherited should use the PSFA_INHERIT action
3099 			 * explicitly.
3100 			 */
3101 			break;
3102 		}
3103 	}
3104 	proc_fdunlock(p);
3105 
3106 	return 0;
3107 }
3108 
3109 #if CONFIG_MACF
3110 /*
3111  * Check that the extension's data is within the bounds of the
3112  * allocation storing all extensions' data
3113  */
3114 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)3115 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
3116     const _ps_mac_policy_extension_t *ext)
3117 {
3118 	uint64_t dataend;
3119 
3120 	if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
3121 		return EOVERFLOW;
3122 	}
3123 	if (__improbable(dataend > px_s->datalen)) {
3124 		return EINVAL;
3125 	}
3126 
3127 	return 0;
3128 }
3129 
3130 /*
3131  * exec_spawnattr_getmacpolicyinfo
3132  */
3133 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)3134 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
3135 {
3136 	const struct ip_px_smpx_s *px_s = macextensions;
3137 	const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
3138 	int i;
3139 
3140 	if (px_s == NULL) {
3141 		return NULL;
3142 	}
3143 
3144 	psmx = px_s->array;
3145 	if (psmx == NULL) {
3146 		return NULL;
3147 	}
3148 
3149 	for (i = 0; i < psmx->psmx_count; i++) {
3150 		const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3151 		if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
3152 			if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
3153 				panic("invalid mac policy extension data");
3154 			}
3155 			if (lenp != NULL) {
3156 				*lenp = (size_t)extension->datalen;
3157 			}
3158 			return (void *)((uintptr_t)px_s->data + extension->dataoff);
3159 		}
3160 	}
3161 
3162 	if (lenp != NULL) {
3163 		*lenp = 0;
3164 	}
3165 	return NULL;
3166 }
3167 
3168 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)3169 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
3170     struct ip_px_smpx_s *pxsp)
3171 {
3172 	_posix_spawn_mac_policy_extensions_t psmx = NULL;
3173 	uint8_t *data = NULL;
3174 	uint64_t datalen = 0;
3175 	uint64_t dataoff = 0;
3176 	int error = 0;
3177 
3178 	bzero(pxsp, sizeof(*pxsp));
3179 
3180 	if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
3181 	    px_args->mac_extensions_size > PAGE_SIZE) {
3182 		error = EINVAL;
3183 		goto bad;
3184 	}
3185 
3186 	psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
3187 	if (psmx == NULL) {
3188 		error = ENOMEM;
3189 		goto bad;
3190 	}
3191 
3192 	error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
3193 	if (error) {
3194 		goto bad;
3195 	}
3196 
3197 	size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
3198 	if (extsize == 0 || extsize > px_args->mac_extensions_size) {
3199 		error = EINVAL;
3200 		goto bad;
3201 	}
3202 
3203 	for (int i = 0; i < psmx->psmx_count; i++) {
3204 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3205 		if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
3206 			error = EINVAL;
3207 			goto bad;
3208 		}
3209 		if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
3210 			error = ENOMEM;
3211 			goto bad;
3212 		}
3213 	}
3214 
3215 	data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
3216 	if (data == NULL) {
3217 		error = ENOMEM;
3218 		goto bad;
3219 	}
3220 
3221 	for (int i = 0; i < psmx->psmx_count; i++) {
3222 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3223 
3224 #if !__LP64__
3225 		if (extension->data > UINT32_MAX) {
3226 			goto bad;
3227 		}
3228 #endif
3229 		error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
3230 		if (error) {
3231 			error = ENOMEM;
3232 			goto bad;
3233 		}
3234 		extension->dataoff = dataoff;
3235 		dataoff += extension->datalen;
3236 	}
3237 
3238 	pxsp->array = psmx;
3239 	pxsp->data = data;
3240 	pxsp->datalen = datalen;
3241 	return 0;
3242 
3243 bad:
3244 	kfree_data(psmx, px_args->mac_extensions_size);
3245 	kfree_data(data, (vm_size_t)datalen);
3246 	return error;
3247 }
3248 #endif /* CONFIG_MACF */
3249 
3250 #if CONFIG_COALITIONS
3251 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])3252 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
3253 {
3254 	for (int c = 0; c < COALITION_NUM_TYPES; c++) {
3255 		if (coal[c]) {
3256 			coalition_remove_active(coal[c]);
3257 			coalition_release(coal[c]);
3258 		}
3259 	}
3260 }
3261 #endif
3262 
3263 #if CONFIG_PERSONAS
3264 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)3265 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
3266 {
3267 	int error = 0;
3268 	struct persona *persona = NULL;
3269 	kauth_cred_t mycred = kauth_cred_get();
3270 
3271 	if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
3272 		return EPERM;
3273 	}
3274 
3275 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3276 		if (px_persona->pspi_ngroups > NGROUPS_MAX) {
3277 			return EINVAL;
3278 		}
3279 	}
3280 
3281 	persona = persona_lookup(px_persona->pspi_id);
3282 	if (!persona) {
3283 		return ESRCH;
3284 	}
3285 
3286 	// non-root process should not be allowed to set persona with uid/gid 0
3287 	if (!kauth_cred_issuser(mycred) &&
3288 	    (px_persona->pspi_uid == 0 || px_persona->pspi_gid == 0)) {
3289 		return EPERM;
3290 	}
3291 
3292 	persona_put(persona);
3293 	return error;
3294 }
3295 
3296 static bool
kauth_cred_model_setpersona(kauth_cred_t model,struct _posix_spawn_persona_info * px_persona)3297 kauth_cred_model_setpersona(
3298 	kauth_cred_t            model,
3299 	struct _posix_spawn_persona_info *px_persona)
3300 {
3301 	bool updated = false;
3302 
3303 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
3304 		updated |= kauth_cred_model_setresuid(model,
3305 		    px_persona->pspi_uid,
3306 		    px_persona->pspi_uid,
3307 		    px_persona->pspi_uid,
3308 		    KAUTH_UID_NONE);
3309 	}
3310 
3311 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
3312 		updated |= kauth_cred_model_setresgid(model,
3313 		    px_persona->pspi_gid,
3314 		    px_persona->pspi_gid,
3315 		    px_persona->pspi_gid);
3316 	}
3317 
3318 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3319 		updated |= kauth_cred_model_setgroups(model,
3320 		    px_persona->pspi_groups,
3321 		    px_persona->pspi_ngroups,
3322 		    px_persona->pspi_gmuid);
3323 	}
3324 
3325 	return updated;
3326 }
3327 
3328 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)3329 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
3330 {
3331 	struct persona *persona = NULL;
3332 
3333 	/*
3334 	 * we want to spawn into the given persona, but we want to override
3335 	 * the kauth with a different UID/GID combo
3336 	 */
3337 	persona = persona_lookup(px_persona->pspi_id);
3338 	if (!persona) {
3339 		return ESRCH;
3340 	}
3341 
3342 	return persona_proc_adopt(p, persona,
3343 	           ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
3344 		return kauth_cred_model_setpersona(model, px_persona);
3345 	});
3346 }
3347 #endif
3348 
3349 #if __arm64__
3350 #if DEVELOPMENT || DEBUG
3351 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
3352     LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
3353 
3354 __startup_func
3355 static void
legacy_footprint_entitlement_mode_init(void)3356 legacy_footprint_entitlement_mode_init(void)
3357 {
3358 	/*
3359 	 * legacy_footprint_entitlement_mode specifies the behavior we want associated
3360 	 * with the entitlement. The supported modes are:
3361 	 *
3362 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3363 	 *	Indicates that we want every process to have the memory accounting
3364 	 *	that is available in iOS 12.0 and beyond.
3365 	 *
3366 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3367 	 *	Indicates that for every process that has the 'legacy footprint entitlement',
3368 	 *      we want to give it the old iOS 11.0 accounting behavior which accounted some
3369 	 *	of the process's memory to the kernel.
3370 	 *
3371 	 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3372 	 *      Indicates that for every process that has the 'legacy footprint entitlement',
3373 	 *	we want it to have a higher memory limit which will help them acclimate to the
3374 	 *	iOS 12.0 (& beyond) accounting behavior that does the right accounting.
3375 	 *      The bonus added to the system-wide task limit to calculate this higher memory limit
3376 	 *      is available in legacy_footprint_bonus_mb.
3377 	 */
3378 
3379 	if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
3380 	    legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
3381 		legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
3382 	}
3383 }
3384 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
3385 #else
3386 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
3387 #endif
3388 
3389 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)3390 proc_legacy_footprint_entitled(proc_t p, task_t task)
3391 {
3392 #pragma unused(p)
3393 	boolean_t legacy_footprint_entitled;
3394 
3395 	switch (legacy_footprint_entitlement_mode) {
3396 	case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3397 		/* the entitlement is ignored */
3398 		break;
3399 	case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3400 		/* the entitlement grants iOS11 legacy accounting */
3401 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3402 		if (legacy_footprint_entitled) {
3403 			task_set_legacy_footprint(task);
3404 		}
3405 		break;
3406 	case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3407 		/* the entitlement grants a footprint limit increase */
3408 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3409 		if (legacy_footprint_entitled) {
3410 			task_set_extra_footprint_limit(task);
3411 		}
3412 		break;
3413 	default:
3414 		break;
3415 	}
3416 }
3417 
3418 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)3419 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
3420 {
3421 #pragma unused(p)
3422 	boolean_t ios13extended_footprint_entitled;
3423 
3424 	/* the entitlement grants a footprint limit increase */
3425 	ios13extended_footprint_entitled = memorystatus_task_has_ios13extended_footprint_limit(proc_task(p));
3426 	if (ios13extended_footprint_entitled) {
3427 		task_set_ios13extended_footprint_limit(task);
3428 	}
3429 }
3430 
3431 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)3432 proc_increased_memory_limit_entitled(proc_t p, task_t task)
3433 {
3434 	if (memorystatus_task_has_increased_debugging_memory_limit_entitlement(task)) {
3435 		memorystatus_act_on_entitled_developer_task_limit(p);
3436 	} else if (memorystatus_task_has_increased_memory_limit_entitlement(task)) {
3437 		memorystatus_act_on_entitled_task_limit(p);
3438 	}
3439 }
3440 
3441 /*
3442  * Check for any of the various entitlements that permit a higher
3443  * task footprint limit or alternate accounting and apply them.
3444  */
3445 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)3446 proc_footprint_entitlement_hacks(proc_t p, task_t task)
3447 {
3448 	proc_legacy_footprint_entitled(p, task);
3449 	proc_ios13extended_footprint_entitled(p, task);
3450 	proc_increased_memory_limit_entitled(p, task);
3451 }
3452 #endif /* __arm64__ */
3453 
3454 /*
3455  * Processes with certain entitlements are granted a jumbo-size VM map.
3456  */
3457 static inline void
proc_apply_jit_and_vm_policies(struct image_params * imgp,proc_t p,task_t task)3458 proc_apply_jit_and_vm_policies(struct image_params *imgp, proc_t p, task_t task)
3459 {
3460 #if CONFIG_MACF
3461 	bool jit_entitled = false;
3462 #endif /* CONFIG_MACF */
3463 	bool needs_jumbo_va = false;
3464 	bool needs_extra_jumbo_va = false;
3465 	struct _posix_spawnattr *psa = imgp->ip_px_sa;
3466 
3467 #if CONFIG_MACF
3468 	jit_entitled = (mac_proc_check_map_anon(p, proc_ucred_unsafe(p),
3469 	    0, 0, 0, MAP_JIT, NULL) == 0);
3470 	needs_jumbo_va = jit_entitled || IOTaskHasEntitlement(task,
3471 	    "com.apple.developer.kernel.extended-virtual-addressing") ||
3472 	    memorystatus_task_has_increased_memory_limit_entitlement(task) ||
3473 	    memorystatus_task_has_increased_debugging_memory_limit_entitlement(task);
3474 #else
3475 #pragma unused(p)
3476 #endif /* CONFIG_MACF */
3477 
3478 
3479 	if (needs_jumbo_va) {
3480 		vm_map_set_jumbo(get_task_map(task));
3481 	}
3482 
3483 	if (psa && psa->psa_max_addr) {
3484 		vm_map_set_max_addr(get_task_map(task), psa->psa_max_addr, false);
3485 	}
3486 
3487 #if CONFIG_MAP_RANGES
3488 	if (task_is_hardened_binary(task) && !proc_is_simulated(p)) {
3489 		/*
3490 		 * This must be done last as it needs to observe
3491 		 * any kind of VA space growth that was requested.
3492 		 * This is used by the secure allocator, so
3493 		 * must be applied to all hardened binaries
3494 		 */
3495 #if XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT
3496 		needs_extra_jumbo_va = IOTaskHasEntitlement(task,
3497 		    "com.apple.kernel.large-file-virtual-addressing");
3498 #endif /* XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT */
3499 		vm_map_range_configure(get_task_map(task), needs_extra_jumbo_va);
3500 	}
3501 #else
3502 #pragma unused(needs_extra_jumbo_va)
3503 #endif /* CONFIG_MAP_RANGES */
3504 
3505 #if CONFIG_MACF
3506 	if (jit_entitled) {
3507 		vm_map_set_jit_entitled(get_task_map(task));
3508 
3509 	}
3510 #endif /* CONFIG_MACF */
3511 
3512 #if XNU_TARGET_OS_OSX
3513 	/* TPRO cannot be enforced on binaries that load 3P plugins on macos - rdar://107420220 */
3514 	const bool task_loads_3P_plugins = imgp->ip_flags & IMGPF_3P_PLUGINS;
3515 #endif /* XNU_TARGET_OS_OSX */
3516 
3517 	if (task_is_hardened_binary(task)
3518 #if XNU_TARGET_OS_OSX
3519 	    && !task_loads_3P_plugins
3520 #endif /* XNU_TARGET_OS_OSX */
3521 	    ) {
3522 		/*
3523 		 * Pre-emptively disable TPRO remapping for
3524 		 * hardened binaries (which do not load 3P plugins)
3525 		 */
3526 		vm_map_set_tpro_enforcement(get_task_map(task));
3527 	}
3528 }
3529 
3530 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)3531 spawn_posix_cred_adopt(proc_t p,
3532     struct _posix_spawn_posix_cred_info *px_pcred_info)
3533 {
3534 	int error = 0;
3535 
3536 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3537 		struct setgid_args args = {
3538 			.gid = px_pcred_info->pspci_gid,
3539 		};
3540 		error = setgid(p, &args, NULL);
3541 		if (error) {
3542 			return error;
3543 		}
3544 	}
3545 
3546 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3547 		error = setgroups_internal(p,
3548 		    px_pcred_info->pspci_ngroups,
3549 		    px_pcred_info->pspci_groups,
3550 		    px_pcred_info->pspci_gmuid);
3551 		if (error) {
3552 			return error;
3553 		}
3554 	}
3555 
3556 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3557 		struct setuid_args args = {
3558 			.uid = px_pcred_info->pspci_uid,
3559 		};
3560 		error = setuid(p, &args, NULL);
3561 		if (error) {
3562 			return error;
3563 		}
3564 	}
3565 	return 0;
3566 }
3567 
3568 /*
3569  * posix_spawn
3570  *
3571  * Parameters:	uap->pid		Pointer to pid return area
3572  *		uap->fname		File name to exec
3573  *		uap->argp		Argument list
3574  *		uap->envp		Environment list
3575  *
3576  * Returns:	0			Success
3577  *		EINVAL			Invalid argument
3578  *		ENOTSUP			Not supported
3579  *		ENOEXEC			Executable file format error
3580  *	exec_activate_image:EINVAL	Invalid argument
3581  *	exec_activate_image:EACCES	Permission denied
3582  *	exec_activate_image:EINTR	Interrupted function
3583  *	exec_activate_image:ENOMEM	Not enough space
3584  *	exec_activate_image:EFAULT	Bad address
3585  *	exec_activate_image:ENAMETOOLONG	Filename too long
3586  *	exec_activate_image:ENOEXEC	Executable file format error
3587  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
3588  *	exec_activate_image:EAUTH	Image decryption failed
3589  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
3590  *	exec_activate_image:???
3591  *	mac_execve_enter:???
3592  *
3593  * TODO:	Expect to need __mac_posix_spawn() at some point...
3594  *		Handle posix_spawnattr_t
3595  *		Handle posix_spawn_file_actions_t
3596  */
3597 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3598 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3599 {
3600 	proc_t p = ap;
3601 	user_addr_t pid = uap->pid;
3602 	int ival[2];            /* dummy retval for setpgid() */
3603 	char *subsystem_root_path = NULL;
3604 	struct image_params *imgp = NULL;
3605 	struct vnode_attr *vap = NULL;
3606 	struct vnode_attr *origvap = NULL;
3607 	struct uthread  *uthread = 0;   /* compiler complains if not set to 0*/
3608 	int error, sig;
3609 	int is_64 = IS_64BIT_PROCESS(p);
3610 	struct vfs_context context;
3611 	struct user__posix_spawn_args_desc px_args = {};
3612 	struct _posix_spawnattr px_sa = {};
3613 	_posix_spawn_file_actions_t px_sfap = NULL;
3614 	_posix_spawn_port_actions_t px_spap = NULL;
3615 	struct __kern_sigaction vec;
3616 	boolean_t spawn_no_exec = FALSE;
3617 	boolean_t proc_transit_set = TRUE;
3618 	boolean_t proc_signal_set = TRUE;
3619 	boolean_t exec_done = FALSE;
3620 	os_reason_t exec_failure_reason = NULL;
3621 
3622 	struct exec_port_actions port_actions = { };
3623 	vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3624 	task_t old_task = current_task();
3625 	task_t new_task = NULL;
3626 	boolean_t should_release_proc_ref = FALSE;
3627 	void *inherit = NULL;
3628 	uint8_t crash_behavior = 0;
3629 	uint64_t crash_behavior_deadline = 0;
3630 #if CONFIG_EXCLAVES
3631 	char *task_conclave_id = NULL;
3632 #endif
3633 #if CONFIG_PERSONAS
3634 	struct _posix_spawn_persona_info *px_persona = NULL;
3635 #endif
3636 	struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3637 	struct {
3638 		struct image_params imgp;
3639 		struct vnode_attr va;
3640 		struct vnode_attr origva;
3641 	} *__spawn_data;
3642 
3643 	/*
3644 	 * Allocate a big chunk for locals instead of using stack since these
3645 	 * structures are pretty big.
3646 	 */
3647 	__spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3648 	if (__spawn_data == NULL) {
3649 		error = ENOMEM;
3650 		goto bad;
3651 	}
3652 	imgp = &__spawn_data->imgp;
3653 	vap = &__spawn_data->va;
3654 	origvap = &__spawn_data->origva;
3655 
3656 	/* Initialize the common data in the image_params structure */
3657 	imgp->ip_user_fname = uap->path;
3658 	imgp->ip_user_argv = uap->argv;
3659 	imgp->ip_user_envv = uap->envp;
3660 	imgp->ip_vattr = vap;
3661 	imgp->ip_origvattr = origvap;
3662 	imgp->ip_vfs_context = &context;
3663 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3664 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3665 	imgp->ip_mac_return = 0;
3666 	imgp->ip_px_persona = NULL;
3667 	imgp->ip_px_pcred_info = NULL;
3668 	imgp->ip_cs_error = OS_REASON_NULL;
3669 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3670 	imgp->ip_subsystem_root_path = NULL;
3671 	imgp->ip_inherited_shared_region_id = NULL;
3672 	imgp->ip_inherited_jop_pid = 0;
3673 	uthread_set_exec_data(current_uthread(), imgp);
3674 
3675 	if (uap->adesc != USER_ADDR_NULL) {
3676 		if (is_64) {
3677 			error = copyin(uap->adesc, &px_args, sizeof(px_args));
3678 		} else {
3679 			struct user32__posix_spawn_args_desc px_args32;
3680 
3681 			error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3682 
3683 			/*
3684 			 * Convert arguments descriptor from external 32 bit
3685 			 * representation to internal 64 bit representation
3686 			 */
3687 			px_args.attr_size = px_args32.attr_size;
3688 			px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3689 			px_args.file_actions_size = px_args32.file_actions_size;
3690 			px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3691 			px_args.port_actions_size = px_args32.port_actions_size;
3692 			px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3693 			px_args.mac_extensions_size = px_args32.mac_extensions_size;
3694 			px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3695 			px_args.coal_info_size = px_args32.coal_info_size;
3696 			px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3697 			px_args.persona_info_size = px_args32.persona_info_size;
3698 			px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3699 			px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3700 			px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3701 			px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3702 			px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3703 			px_args.conclave_id_size = px_args32.conclave_id_size;
3704 			px_args.conclave_id = CAST_USER_ADDR_T(px_args32.conclave_id);
3705 		}
3706 		if (error) {
3707 			goto bad;
3708 		}
3709 
3710 		if (px_args.attr_size != 0) {
3711 			/*
3712 			 * We are not copying the port_actions pointer,
3713 			 * because we already have it from px_args.
3714 			 * This is a bit fragile: <rdar://problem/16427422>
3715 			 */
3716 
3717 			if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3718 				goto bad;
3719 			}
3720 
3721 			imgp->ip_px_sa = &px_sa;
3722 		}
3723 		if (px_args.file_actions_size != 0) {
3724 			/* Limit file_actions to allowed number of open files */
3725 			size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3726 
3727 			if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3728 			    maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3729 				error = EINVAL;
3730 				goto bad;
3731 			}
3732 
3733 			px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3734 			if (px_sfap == NULL) {
3735 				error = ENOMEM;
3736 				goto bad;
3737 			}
3738 			imgp->ip_px_sfa = px_sfap;
3739 
3740 			if ((error = copyin(px_args.file_actions, px_sfap,
3741 			    px_args.file_actions_size)) != 0) {
3742 				goto bad;
3743 			}
3744 
3745 			/* Verify that the action count matches the struct size */
3746 			size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3747 			if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3748 				error = EINVAL;
3749 				goto bad;
3750 			}
3751 		}
3752 		if (px_args.port_actions_size != 0) {
3753 			/* Limit port_actions to one page of data */
3754 			if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3755 			    px_args.port_actions_size > PAGE_SIZE) {
3756 				error = EINVAL;
3757 				goto bad;
3758 			}
3759 
3760 			px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3761 			if (px_spap == NULL) {
3762 				error = ENOMEM;
3763 				goto bad;
3764 			}
3765 			imgp->ip_px_spa = px_spap;
3766 
3767 			if ((error = copyin(px_args.port_actions, px_spap,
3768 			    px_args.port_actions_size)) != 0) {
3769 				goto bad;
3770 			}
3771 
3772 			/* Verify that the action count matches the struct size */
3773 			size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3774 			if (pasize == 0 || pasize != px_args.port_actions_size) {
3775 				error = EINVAL;
3776 				goto bad;
3777 			}
3778 		}
3779 #if CONFIG_PERSONAS
3780 		/* copy in the persona info */
3781 		if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3782 			/* for now, we need the exact same struct in user space */
3783 			if (px_args.persona_info_size != sizeof(*px_persona)) {
3784 				error = ERANGE;
3785 				goto bad;
3786 			}
3787 
3788 			px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3789 			if (px_persona == NULL) {
3790 				error = ENOMEM;
3791 				goto bad;
3792 			}
3793 			imgp->ip_px_persona = px_persona;
3794 
3795 			if ((error = copyin(px_args.persona_info, px_persona,
3796 			    px_args.persona_info_size)) != 0) {
3797 				goto bad;
3798 			}
3799 			if ((error = spawn_validate_persona(px_persona)) != 0) {
3800 				goto bad;
3801 			}
3802 		}
3803 #endif
3804 		/* copy in the posix cred info */
3805 		if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
3806 			/* for now, we need the exact same struct in user space */
3807 			if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
3808 				error = ERANGE;
3809 				goto bad;
3810 			}
3811 
3812 			if (!kauth_cred_issuser(kauth_cred_get())) {
3813 				error = EPERM;
3814 				goto bad;
3815 			}
3816 
3817 			px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
3818 			if (px_pcred_info == NULL) {
3819 				error = ENOMEM;
3820 				goto bad;
3821 			}
3822 			imgp->ip_px_pcred_info = px_pcred_info;
3823 
3824 			if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
3825 			    px_args.posix_cred_info_size)) != 0) {
3826 				goto bad;
3827 			}
3828 
3829 			if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3830 				if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
3831 					error = EINVAL;
3832 					goto bad;
3833 				}
3834 			}
3835 		}
3836 #if CONFIG_MACF
3837 		if (px_args.mac_extensions_size != 0) {
3838 			if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
3839 				goto bad;
3840 			}
3841 		}
3842 #endif /* CONFIG_MACF */
3843 		if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
3844 			/*
3845 			 * If a valid-looking subsystem root has been
3846 			 * specified...
3847 			 */
3848 			if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
3849 				/*
3850 				 * ...AND the parent has the entitlement, copy
3851 				 * the subsystem root path in.
3852 				 */
3853 				subsystem_root_path = zalloc_flags(ZV_NAMEI,
3854 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3855 
3856 				if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
3857 					goto bad;
3858 				}
3859 
3860 				/* Paranoia */
3861 				subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
3862 			}
3863 		}
3864 #if CONFIG_EXCLAVES
3865 		if ((px_args.conclave_id_size > 0) && (px_args.conclave_id_size <= MAXCONCLAVENAME) &&
3866 		    (exclaves_boot_wait(EXCLAVES_BOOT_STAGE_EXCLAVEKIT) == KERN_SUCCESS)) {
3867 			if (px_args.conclave_id) {
3868 				if (imgp->ip_px_sa != NULL && (px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3869 					/* Conclave id could be set only for true spawn */
3870 					error = EINVAL;
3871 					goto bad;
3872 				}
3873 				task_conclave_id = kalloc_data(MAXCONCLAVENAME,
3874 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3875 				if ((error = copyin(px_args.conclave_id, task_conclave_id, MAXCONCLAVENAME))) {
3876 					goto bad;
3877 				}
3878 				task_conclave_id[MAXCONCLAVENAME - 1] = 0;
3879 			}
3880 		}
3881 #endif
3882 	}
3883 
3884 	if (IOTaskHasEntitlement(old_task, SPAWN_SET_PANIC_CRASH_BEHAVIOR)) {
3885 		/* Truncate to uint8_t since we only support 2 flags for now */
3886 		crash_behavior = (uint8_t)px_sa.psa_crash_behavior;
3887 		crash_behavior_deadline = px_sa.psa_crash_behavior_deadline;
3888 	}
3889 
3890 	/* set uthread to parent */
3891 	uthread = current_uthread();
3892 
3893 	/*
3894 	 * <rdar://6640530>; this does not result in a behaviour change
3895 	 * relative to Leopard, so there should not be any existing code
3896 	 * which depends on it.
3897 	 */
3898 
3899 	if (imgp->ip_px_sa != NULL) {
3900 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
3901 		if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
3902 			imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
3903 		}
3904 #if (DEVELOPMENT || DEBUG)
3905 		if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
3906 			imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
3907 		}
3908 #endif
3909 
3910 		if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
3911 			goto bad;
3912 		}
3913 	}
3914 
3915 	/*
3916 	 * If we don't have the extension flag that turns "posix_spawn()"
3917 	 * into "execve() with options", then we will be creating a new
3918 	 * process which does not inherit memory from the parent process,
3919 	 * which is one of the most expensive things about using fork()
3920 	 * and execve().
3921 	 */
3922 	if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3923 		/* Set the new task's coalition, if it is requested.  */
3924 		coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
3925 #if CONFIG_COALITIONS
3926 		int i, ncoals;
3927 		kern_return_t kr = KERN_SUCCESS;
3928 		struct _posix_spawn_coalition_info coal_info;
3929 		int coal_role[COALITION_NUM_TYPES];
3930 
3931 		if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
3932 			goto do_fork1;
3933 		}
3934 
3935 		memset(&coal_info, 0, sizeof(coal_info));
3936 
3937 		if (px_args.coal_info_size > sizeof(coal_info)) {
3938 			px_args.coal_info_size = sizeof(coal_info);
3939 		}
3940 		error = copyin(px_args.coal_info,
3941 		    &coal_info, px_args.coal_info_size);
3942 		if (error != 0) {
3943 			goto bad;
3944 		}
3945 
3946 		ncoals = 0;
3947 		for (i = 0; i < COALITION_NUM_TYPES; i++) {
3948 			uint64_t cid = coal_info.psci_info[i].psci_id;
3949 			if (cid != 0) {
3950 				/*
3951 				 * don't allow tasks which are not in a
3952 				 * privileged coalition to spawn processes
3953 				 * into coalitions other than their own
3954 				 */
3955 				if (!task_is_in_privileged_coalition(proc_task(p), i) &&
3956 				    !IOTaskHasEntitlement(proc_task(p), COALITION_SPAWN_ENTITLEMENT)) {
3957 					coal_dbg("ERROR: %d not in privilegd "
3958 					    "coalition of type %d",
3959 					    proc_getpid(p), i);
3960 					spawn_coalitions_release_all(coal);
3961 					error = EPERM;
3962 					goto bad;
3963 				}
3964 
3965 				coal_dbg("searching for coalition id:%llu", cid);
3966 				/*
3967 				 * take a reference and activation on the
3968 				 * coalition to guard against free-while-spawn
3969 				 * races
3970 				 */
3971 				coal[i] = coalition_find_and_activate_by_id(cid);
3972 				if (coal[i] == COALITION_NULL) {
3973 					coal_dbg("could not find coalition id:%llu "
3974 					    "(perhaps it has been terminated or reaped)", cid);
3975 					/*
3976 					 * release any other coalition's we
3977 					 * may have a reference to
3978 					 */
3979 					spawn_coalitions_release_all(coal);
3980 					error = ESRCH;
3981 					goto bad;
3982 				}
3983 				if (coalition_type(coal[i]) != i) {
3984 					coal_dbg("coalition with id:%lld is not of type:%d"
3985 					    " (it's type:%d)", cid, i, coalition_type(coal[i]));
3986 					spawn_coalitions_release_all(coal);
3987 					error = ESRCH;
3988 					goto bad;
3989 				}
3990 				coal_role[i] = coal_info.psci_info[i].psci_role;
3991 				ncoals++;
3992 			}
3993 		}
3994 		if (ncoals < COALITION_NUM_TYPES) {
3995 			/*
3996 			 * If the user is attempting to spawn into a subset of
3997 			 * the known coalition types, then make sure they have
3998 			 * _at_least_ specified a resource coalition. If not,
3999 			 * the following fork1() call will implicitly force an
4000 			 * inheritance from 'p' and won't actually spawn the
4001 			 * new task into the coalitions the user specified.
4002 			 * (also the call to coalitions_set_roles will panic)
4003 			 */
4004 			if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
4005 				spawn_coalitions_release_all(coal);
4006 				error = EINVAL;
4007 				goto bad;
4008 			}
4009 		}
4010 do_fork1:
4011 #endif /* CONFIG_COALITIONS */
4012 
4013 		/*
4014 		 * note that this will implicitly inherit the
4015 		 * caller's persona (if it exists)
4016 		 */
4017 		error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
4018 		/* returns a thread and task reference */
4019 
4020 		if (error == 0) {
4021 			new_task = get_threadtask(imgp->ip_new_thread);
4022 		}
4023 #if CONFIG_COALITIONS
4024 		/* set the roles of this task within each given coalition */
4025 		if (error == 0) {
4026 			kr = coalitions_set_roles(coal, new_task, coal_role);
4027 			if (kr != KERN_SUCCESS) {
4028 				error = EINVAL;
4029 			}
4030 			if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
4031 			    MACH_COALITION_ADOPT))) {
4032 				for (i = 0; i < COALITION_NUM_TYPES; i++) {
4033 					if (coal[i] != COALITION_NULL) {
4034 						/*
4035 						 * On 32-bit targets, uniqueid
4036 						 * will get truncated to 32 bits
4037 						 */
4038 						KDBG_RELEASE(MACHDBG_CODE(
4039 							    DBG_MACH_COALITION,
4040 							    MACH_COALITION_ADOPT),
4041 						    coalition_id(coal[i]),
4042 						    get_task_uniqueid(new_task));
4043 					}
4044 				}
4045 			}
4046 		}
4047 
4048 		/* drop our references and activations - fork1() now holds them */
4049 		spawn_coalitions_release_all(coal);
4050 #endif /* CONFIG_COALITIONS */
4051 		if (error != 0) {
4052 			goto bad;
4053 		}
4054 		imgp->ip_flags |= IMGPF_SPAWN;  /* spawn w/o exec */
4055 		spawn_no_exec = TRUE;           /* used in later tests */
4056 	} else {
4057 		/* Adjust the user proc count */
4058 		(void)chgproccnt(kauth_getruid(), 1);
4059 		/*
4060 		 * For execve case, create a new proc, task and thread
4061 		 * but don't make the proc visible to userland. After
4062 		 * image activation, the new proc would take place of
4063 		 * the old proc in pid hash and other lists that make
4064 		 * the proc visible to the system.
4065 		 */
4066 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
4067 
4068 		/* task and thread ref returned by cloneproc */
4069 		if (imgp->ip_new_thread == NULL) {
4070 			(void)chgproccnt(kauth_getruid(), -1);
4071 			error = ENOMEM;
4072 			goto bad;
4073 		}
4074 
4075 		new_task = get_threadtask(imgp->ip_new_thread);
4076 		imgp->ip_flags |= IMGPF_EXEC;
4077 	}
4078 
4079 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
4080 
4081 	if (spawn_no_exec) {
4082 		/*
4083 		 * We had to wait until this point before firing the
4084 		 * proc:::create probe, otherwise p would not point to the
4085 		 * child process.
4086 		 */
4087 		DTRACE_PROC1(create, proc_t, p);
4088 	}
4089 	assert(p != NULL);
4090 
4091 	if (subsystem_root_path) {
4092 		/* If a subsystem root was specified, swap it in */
4093 		char * old_subsystem_root_path = p->p_subsystem_root_path;
4094 		p->p_subsystem_root_path = subsystem_root_path;
4095 		subsystem_root_path = old_subsystem_root_path;
4096 	}
4097 
4098 	p->p_crash_behavior = crash_behavior;
4099 	p->p_crash_behavior_deadline = crash_behavior_deadline;
4100 
4101 	p->p_crash_count = px_sa.psa_crash_count;
4102 	p->p_throttle_timeout = px_sa.psa_throttle_timeout;
4103 
4104 	/* We'll need the subsystem root for setting up Apple strings */
4105 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4106 
4107 	context.vc_thread = imgp->ip_new_thread;
4108 	context.vc_ucred = proc_ucred_unsafe(p);  /* in init */
4109 
4110 	/*
4111 	 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
4112 	 * to handle the file_actions.
4113 	 */
4114 
4115 	/* Has spawn file actions? */
4116 	if (imgp->ip_px_sfa != NULL) {
4117 		/*
4118 		 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
4119 		 * is handled in exec_handle_file_actions().
4120 		 */
4121 #if CONFIG_AUDIT
4122 		/*
4123 		 * The file actions auditing can overwrite the upath of
4124 		 * AUE_POSIX_SPAWN audit record.  Save the audit record.
4125 		 */
4126 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4127 		uthread->uu_ar = NULL;
4128 #endif
4129 		error = exec_handle_file_actions(imgp,
4130 		    imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
4131 #if CONFIG_AUDIT
4132 		/* Restore the AUE_POSIX_SPAWN audit record. */
4133 		uthread->uu_ar = save_uu_ar;
4134 #endif
4135 		if (error != 0) {
4136 			goto bad;
4137 		}
4138 	}
4139 
4140 	/* Has spawn port actions? */
4141 	if (imgp->ip_px_spa != NULL) {
4142 #if CONFIG_AUDIT
4143 		/*
4144 		 * Do the same for the port actions as we did for the file
4145 		 * actions.  Save the AUE_POSIX_SPAWN audit record.
4146 		 */
4147 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4148 		uthread->uu_ar = NULL;
4149 #endif
4150 		error = exec_handle_port_actions(imgp, &port_actions);
4151 #if CONFIG_AUDIT
4152 		/* Restore the AUE_POSIX_SPAWN audit record. */
4153 		uthread->uu_ar = save_uu_ar;
4154 #endif
4155 		if (error != 0) {
4156 			goto bad;
4157 		}
4158 	}
4159 
4160 	/* Has spawn attr? */
4161 	if (imgp->ip_px_sa != NULL) {
4162 		/*
4163 		 * Reset UID/GID to parent's RUID/RGID; This works only
4164 		 * because the operation occurs before the call
4165 		 * to exec_handle_sugid() by the image activator called
4166 		 * from exec_activate_image().
4167 		 *
4168 		 * POSIX requires that any setuid/setgid bits on the process
4169 		 * image will take precedence over the spawn attributes
4170 		 * (re)setting them.
4171 		 *
4172 		 * Modifications to p_ucred must be guarded using the
4173 		 * proc's ucred lock. This prevents others from accessing
4174 		 * a garbage credential.
4175 		 */
4176 		if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
4177 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
4178 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model){
4179 				return kauth_cred_model_setuidgid(model,
4180 				kauth_cred_getruid(parent),
4181 				kauth_cred_getrgid(parent));
4182 			});
4183 		}
4184 
4185 		if (imgp->ip_px_pcred_info) {
4186 			if (!spawn_no_exec) {
4187 				error = ENOTSUP;
4188 				goto bad;
4189 			}
4190 
4191 			error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
4192 			if (error != 0) {
4193 				goto bad;
4194 			}
4195 		}
4196 
4197 #if CONFIG_PERSONAS
4198 		if (imgp->ip_px_persona != NULL) {
4199 			if (!spawn_no_exec) {
4200 				error = ENOTSUP;
4201 				goto bad;
4202 			}
4203 
4204 			/*
4205 			 * If we were asked to spawn a process into a new persona,
4206 			 * do the credential switch now (which may override the UID/GID
4207 			 * inherit done just above). It's important to do this switch
4208 			 * before image activation both for reasons stated above, and
4209 			 * to ensure that the new persona has access to the image/file
4210 			 * being executed.
4211 			 */
4212 			error = spawn_persona_adopt(p, imgp->ip_px_persona);
4213 			if (error != 0) {
4214 				goto bad;
4215 			}
4216 		}
4217 #endif /* CONFIG_PERSONAS */
4218 #if !SECURE_KERNEL
4219 		/*
4220 		 * Disable ASLR for the spawned process.
4221 		 *
4222 		 * But only do so if we are not embedded + RELEASE.
4223 		 * While embedded allows for a boot-arg (-disable_aslr)
4224 		 * to deal with this (which itself is only honored on
4225 		 * DEVELOPMENT or DEBUG builds of xnu), it is often
4226 		 * useful or necessary to disable ASLR on a per-process
4227 		 * basis for unit testing and debugging.
4228 		 */
4229 		if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
4230 			OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
4231 		}
4232 #endif /* !SECURE_KERNEL */
4233 
4234 		/* Randomize high bits of ASLR slide */
4235 		if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
4236 			imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
4237 		}
4238 
4239 #if !SECURE_KERNEL
4240 		/*
4241 		 * Forcibly disallow execution from data pages for the spawned process
4242 		 * even if it would otherwise be permitted by the architecture default.
4243 		 */
4244 		if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
4245 			imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
4246 		}
4247 #endif /* !SECURE_KERNEL */
4248 
4249 #if     __has_feature(ptrauth_calls)
4250 		if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
4251 			imgp->ip_flags |= IMGPF_RESLIDE;
4252 		}
4253 #endif /* __has_feature(ptrauth_calls) */
4254 
4255 		if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
4256 		    POSIX_SPAWN_PROC_TYPE_DRIVER) {
4257 			imgp->ip_flags |= IMGPF_DRIVER;
4258 		}
4259 	}
4260 
4261 	/*
4262 	 * Disable ASLR during image activation.  This occurs either if the
4263 	 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
4264 	 * P_DISABLE_ASLR was inherited from the parent process.
4265 	 */
4266 	if (p->p_flag & P_DISABLE_ASLR) {
4267 		imgp->ip_flags |= IMGPF_DISABLE_ASLR;
4268 	}
4269 
4270 	/*
4271 	 * Clear transition flag so we won't hang if exec_activate_image() causes
4272 	 * an automount (and launchd does a proc sysctl to service it).
4273 	 *
4274 	 * <rdar://problem/6848672>, <rdar://problem/5959568>.
4275 	 */
4276 	proc_transend(p, 0);
4277 	proc_transit_set = 0;
4278 
4279 	if (!spawn_no_exec) {
4280 		/*
4281 		 * Clear the signal lock in case of exec, since
4282 		 * image activation uses psignal on child process.
4283 		 */
4284 		proc_signalend(p, 0);
4285 		proc_signal_set = 0;
4286 	}
4287 
4288 #if MAC_SPAWN   /* XXX */
4289 	if (uap->mac_p != USER_ADDR_NULL) {
4290 		error = mac_execve_enter(uap->mac_p, imgp);
4291 		if (error) {
4292 			goto bad;
4293 		}
4294 	}
4295 #endif
4296 
4297 
4298 	/*
4299 	 * Activate the image.
4300 	 * Warning: If activation failed after point of no return, it returns error
4301 	 * as 0 and pretends the call succeeded.
4302 	 */
4303 	error = exec_activate_image(imgp);
4304 #if defined(HAS_APPLE_PAC)
4305 	const uint8_t disable_user_jop = imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE;
4306 	ml_task_set_jop_pid_from_shared_region(new_task, disable_user_jop);
4307 	ml_task_set_disable_user_jop(new_task, disable_user_jop);
4308 	ml_thread_set_disable_user_jop(imgp->ip_new_thread, disable_user_jop);
4309 	ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4310 #endif
4311 
4312 
4313 	/*
4314 	 * If you've come here to add support for some new HW feature or some per-process or per-vmmap
4315 	 * or per-pmap flag that needs to be set before the process runs, or are in general lost, here
4316 	 * is some help. This summary was accurate as of Jul 2022. Use git log as needed. This comment
4317 	 * is here to prevent a recurrence of rdar://96307913
4318 	 *
4319 	 * In posix_spawn, following is what happens:
4320 	 * 1. Lots of prep and checking work
4321 	 * 2. Image activation via exec_activate_image(). The new task will get a new pmap here
4322 	 * 3. More prep work. (YOU ARE HERE)
4323 	 * 4. exec_resettextvp() is called
4324 	 * 5. At this point it is safe to check entitlements and code signatures
4325 	 * 6. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4326 	 *    The new thread is allowed to run in kernel. It cannot yet get to userland
4327 	 * 7. More things done here. This is your chance to affect the task before it runs in
4328 	 *    userspace
4329 	 * 8. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4330 	 *     The new thread is allowed to run in userland
4331 	 */
4332 
4333 	if (error == 0 && !spawn_no_exec) {
4334 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
4335 		/* proc ref returned */
4336 		should_release_proc_ref = TRUE;
4337 	}
4338 
4339 	if (error == 0) {
4340 		/* process completed the exec, but may have failed after point of no return */
4341 		exec_done = TRUE;
4342 	}
4343 
4344 #if CONFIG_EXCLAVES
4345 	if (!error && task_conclave_id != NULL) {
4346 		kern_return_t kr;
4347 		kr = task_add_conclave(new_task, imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
4348 		    task_conclave_id);
4349 		if (kr != KERN_SUCCESS) {
4350 			error = EINVAL;
4351 			goto bad;
4352 		}
4353 	}
4354 #endif
4355 
4356 	if (!error && imgp->ip_px_sa != NULL) {
4357 		thread_t child_thread = imgp->ip_new_thread;
4358 		uthread_t child_uthread = get_bsdthread_info(child_thread);
4359 
4360 		/*
4361 		 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
4362 		 * activation, else when image activation fails (before the point of no
4363 		 * return) would leave the parent process in a modified state.
4364 		 */
4365 		if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
4366 			struct setpgid_args spga;
4367 			spga.pid = proc_getpid(p);
4368 			spga.pgid = px_sa.psa_pgroup;
4369 			/*
4370 			 * Effectively, call setpgid() system call; works
4371 			 * because there are no pointer arguments.
4372 			 */
4373 			if ((error = setpgid(p, &spga, ival)) != 0) {
4374 				goto bad_px_sa;
4375 			}
4376 		}
4377 
4378 		if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
4379 			error = setsid_internal(p);
4380 			if (error != 0) {
4381 				goto bad_px_sa;
4382 			}
4383 		}
4384 
4385 		/*
4386 		 * If we have a spawn attr, and it contains signal related flags,
4387 		 * the we need to process them in the "context" of the new child
4388 		 * process, so we have to process it following image activation,
4389 		 * prior to making the thread runnable in user space.  This is
4390 		 * necessitated by some signal information being per-thread rather
4391 		 * than per-process, and we don't have the new allocation in hand
4392 		 * until after the image is activated.
4393 		 */
4394 
4395 		/*
4396 		 * Mask a list of signals, instead of them being unmasked, if
4397 		 * they were unmasked in the parent; note that some signals
4398 		 * are not maskable.
4399 		 */
4400 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
4401 			child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
4402 		}
4403 		/*
4404 		 * Default a list of signals instead of ignoring them, if
4405 		 * they were ignored in the parent.  Note that we pass
4406 		 * spawn_no_exec to setsigvec() to indicate that we called
4407 		 * fork1() and therefore do not need to call proc_signalstart()
4408 		 * internally.
4409 		 */
4410 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
4411 			vec.sa_handler = SIG_DFL;
4412 			vec.sa_tramp = 0;
4413 			vec.sa_mask = 0;
4414 			vec.sa_flags = 0;
4415 			for (sig = 1; sig < NSIG; sig++) {
4416 				if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
4417 					error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
4418 				}
4419 			}
4420 		}
4421 
4422 		/*
4423 		 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
4424 		 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
4425 		 * limit.
4426 		 *
4427 		 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
4428 		 */
4429 		if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
4430 			/*
4431 			 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
4432 			 * an entitlement to configure the monitor a certain way seems silly, since
4433 			 * whomever is turning it on could just as easily choose not to do so.
4434 			 */
4435 			error = proc_set_task_ruse_cpu(proc_task(p),
4436 			    TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
4437 			    (uint8_t)px_sa.psa_cpumonitor_percent,
4438 			    px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
4439 			    0, TRUE);
4440 		}
4441 
4442 
4443 		if (px_pcred_info &&
4444 		    (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
4445 			/*
4446 			 * setlogin() must happen after setsid()
4447 			 */
4448 			setlogin_internal(p, px_pcred_info->pspci_login);
4449 		}
4450 
4451 bad_px_sa:
4452 		if (error != 0) {
4453 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
4454 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR, 0, 0);
4455 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR);
4456 		}
4457 	}
4458 
4459 bad:
4460 
4461 	if (error == 0) {
4462 		/* reset delay idle sleep status if set */
4463 #if CONFIG_DELAY_IDLE_SLEEP
4464 		if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
4465 			OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
4466 		}
4467 #endif /* CONFIG_DELAY_IDLE_SLEEP */
4468 		/* upon  successful spawn, re/set the proc control state */
4469 		if (imgp->ip_px_sa != NULL) {
4470 			switch (px_sa.psa_pcontrol) {
4471 			case POSIX_SPAWN_PCONTROL_THROTTLE:
4472 				p->p_pcaction = P_PCTHROTTLE;
4473 				break;
4474 			case POSIX_SPAWN_PCONTROL_SUSPEND:
4475 				p->p_pcaction = P_PCSUSP;
4476 				break;
4477 			case POSIX_SPAWN_PCONTROL_KILL:
4478 				p->p_pcaction = P_PCKILL;
4479 				break;
4480 			case POSIX_SPAWN_PCONTROL_NONE:
4481 			default:
4482 				p->p_pcaction = 0;
4483 				break;
4484 			}
4485 			;
4486 		}
4487 		exec_resettextvp(p, imgp);
4488 
4489 		/*
4490 		 * Enable new task IPC access if exec_activate_image() returned an
4491 		 * active task. (Checks active bit in ipc_task_enable() under lock).
4492 		 * Must enable after resettextvp so that task port policies are not evaluated
4493 		 * until the csblob in the textvp is accurately reflected.
4494 		 */
4495 		ipc_task_enable(new_task);
4496 
4497 		/* Set task exception ports now that we can check entitlements */
4498 		if (imgp->ip_px_spa != NULL) {
4499 			error = exec_handle_exception_port_actions(imgp, &port_actions);
4500 		}
4501 
4502 #if CONFIG_MEMORYSTATUS
4503 		/* Set jetsam priority for DriverKit processes */
4504 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4505 			px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
4506 		}
4507 
4508 		/* Has jetsam attributes? */
4509 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
4510 			int32_t memlimit_active = px_sa.psa_memlimit_active;
4511 			int32_t memlimit_inactive = px_sa.psa_memlimit_inactive;
4512 
4513 			memstat_priority_options_t priority_options = MEMSTAT_PRIORITY_OPTIONS_NONE;
4514 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY)) {
4515 				priority_options |= MEMSTAT_PRIORITY_IS_EFFECTIVE;
4516 			}
4517 			memorystatus_set_priority(p, px_sa.psa_priority, 0,
4518 			    priority_options);
4519 
4520 			memlimit_options_t memlimit_options = MEMLIMIT_OPTIONS_NONE;
4521 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL)) {
4522 				memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
4523 			}
4524 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL)) {
4525 				memlimit_options |= MEMLIMIT_INACTIVE_FATAL;
4526 			}
4527 			if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
4528 				/*
4529 				 * With 2-level high-water-mark support,
4530 				 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no longer relevant,
4531 				 * as background limits are described via the inactive limit
4532 				 * slots. However, if the
4533 				 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in, we
4534 				 * attempt to mimic previous behavior by forcing the BG limit
4535 				 * data into the inactive/non-fatal mode and force the active
4536 				 * slots to hold system_wide/fatal mode.
4537 				 */
4538 				memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
4539 				memlimit_options &= ~MEMLIMIT_INACTIVE_FATAL;
4540 				memlimit_active = -1;
4541 			}
4542 			memorystatus_set_memlimits(p, memlimit_active, memlimit_inactive,
4543 			    memlimit_options);
4544 		}
4545 
4546 		/* Has jetsam relaunch behavior? */
4547 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
4548 			/*
4549 			 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
4550 			 * This data would be used by the jetsam subsystem to determine the position and protection
4551 			 * offered to this process on dirty -> clean transitions.
4552 			 */
4553 			int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
4554 			switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
4555 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
4556 				relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
4557 				break;
4558 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
4559 				relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
4560 				break;
4561 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
4562 				relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
4563 				break;
4564 			default:
4565 				break;
4566 			}
4567 			memorystatus_relaunch_flags_update(p, relaunch_flags);
4568 		}
4569 
4570 #endif /* CONFIG_MEMORYSTATUS */
4571 		if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
4572 			task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
4573 		}
4574 
4575 #if CONFIG_PROC_RESOURCE_LIMITS
4576 		if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
4577 			task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
4578 			    (uint32_t)px_sa.psa_port_hard_limit);
4579 		}
4580 
4581 		if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
4582 			proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
4583 			    (int)px_sa.psa_filedesc_hard_limit);
4584 		}
4585 		if (imgp->ip_px_sa != NULL && (px_sa.psa_kqworkloop_soft_limit > 0 || px_sa.psa_kqworkloop_hard_limit > 0)) {
4586 			proc_set_kqworkloop_limits(p, (int)px_sa.psa_kqworkloop_soft_limit,
4587 			    (int)px_sa.psa_kqworkloop_hard_limit);
4588 		}
4589 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
4590 
4591 		/* Disable wakeup monitoring for DriverKit processes */
4592 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4593 			uint32_t      flags = WAKEMON_DISABLE;
4594 			task_wakeups_monitor_ctl(new_task, &flags, NULL);
4595 		}
4596 	}
4597 
4598 
4599 	/*
4600 	 * If we successfully called fork1() or cloneproc, we always need
4601 	 * to do this. This is because we come back from that call with
4602 	 * signals blocked in the child, and we have to unblock them, for exec
4603 	 * case they are unblocked before activation, but for true spawn case
4604 	 * we want to wait until after we've performed any spawn actions.
4605 	 * This has to happen before process_signature(), which uses psignal.
4606 	 */
4607 	if (proc_transit_set) {
4608 		proc_transend(p, 0);
4609 	}
4610 
4611 	/*
4612 	 * Drop the signal lock on the child which was taken on our
4613 	 * behalf by forkproc()/cloneproc() to prevent signals being
4614 	 * received by the child in a partially constructed state.
4615 	 */
4616 	if (proc_signal_set) {
4617 		proc_signalend(p, 0);
4618 	}
4619 
4620 	if (error == 0) {
4621 		/*
4622 		 * We need to initialize the bank context behind the protection of
4623 		 * the proc_trans lock to prevent a race with exit. We can't do this during
4624 		 * exec_activate_image because task_bank_init checks entitlements that
4625 		 * aren't loaded until subsequent calls (including exec_resettextvp).
4626 		 */
4627 		error = proc_transstart(p, 0, 0);
4628 
4629 		if (error == 0) {
4630 			task_bank_init(new_task);
4631 			proc_transend(p, 0);
4632 		}
4633 
4634 #if __arm64__
4635 		proc_footprint_entitlement_hacks(p, new_task);
4636 #endif /* __arm64__ */
4637 
4638 #if XNU_TARGET_OS_OSX
4639 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4640 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4641 			vm_map_single_jit(get_task_map(new_task));
4642 		}
4643 #endif /* XNU_TARGET_OS_OSX */
4644 
4645 #if __has_feature(ptrauth_calls)
4646 		task_set_pac_exception_fatal_flag(new_task);
4647 #endif /* __has_feature(ptrauth_calls) */
4648 		task_set_jit_exception_fatal_flag(new_task);
4649 	}
4650 
4651 	/* Inherit task role from old task to new task for exec */
4652 	if (error == 0 && !spawn_no_exec) {
4653 		proc_inherit_task_role(new_task, old_task);
4654 	}
4655 
4656 #if CONFIG_ARCADE
4657 	if (error == 0) {
4658 		/*
4659 		 * Check to see if we need to trigger an arcade upcall AST now
4660 		 * that the vnode has been reset on the task.
4661 		 */
4662 		arcade_prepare(new_task, imgp->ip_new_thread);
4663 	}
4664 #endif /* CONFIG_ARCADE */
4665 
4666 	if (error == 0) {
4667 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
4668 	}
4669 
4670 	/* Clear the initial wait on the thread before handling spawn policy */
4671 	if (imgp && imgp->ip_new_thread) {
4672 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4673 	}
4674 
4675 	/*
4676 	 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4677 	 * and bind any portwatch ports to the new task.
4678 	 * This must be done after the exec so that the child's thread is ready,
4679 	 * and after the in transit state has been released, because priority is
4680 	 * dropped here so we need to be prepared for a potentially long preemption interval
4681 	 *
4682 	 * TODO: Consider splitting this up into separate phases
4683 	 */
4684 	if (error == 0 && imgp->ip_px_sa != NULL) {
4685 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4686 
4687 		error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4688 		    psa->psa_darwin_role, &port_actions);
4689 	}
4690 
4691 	/* Transfer the turnstile watchport boost to new task if in exec */
4692 	if (error == 0 && !spawn_no_exec) {
4693 		task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4694 	}
4695 
4696 	if (error == 0 && imgp->ip_px_sa != NULL) {
4697 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4698 
4699 		if (psa->psa_no_smt) {
4700 			task_set_no_smt(new_task);
4701 		}
4702 		if (psa->psa_tecs) {
4703 			task_set_tecs(new_task);
4704 		}
4705 	}
4706 
4707 	if (error == 0 && imgp->ip_px_sa != NULL) {
4708 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4709 
4710 		if (psa->psa_options & PSA_OPTION_DATALESS_IOPOLICY) {
4711 			struct _iopol_param_t iop_param = {
4712 				.iop_scope = IOPOL_SCOPE_PROCESS,
4713 				.iop_iotype = IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES,
4714 				.iop_policy = psa->psa_dataless_iopolicy,
4715 			};
4716 			error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_SET, iop_param.iop_scope,
4717 			    iop_param.iop_policy, &iop_param);
4718 		}
4719 	}
4720 
4721 	if (error == 0) {
4722 		/* Apply the main thread qos */
4723 		thread_t main_thread = imgp->ip_new_thread;
4724 		task_set_main_thread_qos(new_task, main_thread);
4725 	}
4726 
4727 	/*
4728 	 * Release any ports we kept around for binding to the new task
4729 	 * We need to release the rights even if the posix_spawn has failed.
4730 	 */
4731 	if (imgp->ip_px_spa != NULL) {
4732 		exec_port_actions_destroy(&port_actions);
4733 	}
4734 
4735 	/*
4736 	 * We have to delay operations which might throw a signal until after
4737 	 * the signals have been unblocked; however, we want that to happen
4738 	 * after exec_resettextvp() so that the textvp is correct when they
4739 	 * fire.
4740 	 */
4741 	if (error == 0) {
4742 		error = process_signature(p, imgp);
4743 
4744 		/*
4745 		 * Pay for our earlier safety; deliver the delayed signals from
4746 		 * the incomplete spawn process now that it's complete.
4747 		 */
4748 		if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4749 			psignal_vfork(p, proc_task(p), imgp->ip_new_thread, SIGTRAP);
4750 		}
4751 
4752 		if (error == 0 && !spawn_no_exec) {
4753 			KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4754 			    proc_getpid(p));
4755 		}
4756 	}
4757 
4758 	if (spawn_no_exec) {
4759 		/* flag the 'fork' has occurred */
4760 		proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4761 	}
4762 
4763 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
4764 	if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4765 		proc_knote(p, NOTE_EXEC);
4766 	}
4767 
4768 	if (imgp != NULL) {
4769 		uthread_set_exec_data(current_uthread(), NULL);
4770 		if (imgp->ip_vp) {
4771 			vnode_put(imgp->ip_vp);
4772 		}
4773 		if (imgp->ip_scriptvp) {
4774 			vnode_put(imgp->ip_scriptvp);
4775 		}
4776 		if (imgp->ip_strings) {
4777 			execargs_free(imgp);
4778 		}
4779 		if (imgp->ip_free_map) {
4780 			/* Free the map after dropping iocount on vnode to avoid deadlock */
4781 			vm_map_deallocate(imgp->ip_free_map);
4782 		}
4783 		kfree_data(imgp->ip_px_sfa,
4784 		    px_args.file_actions_size);
4785 		kfree_data(imgp->ip_px_spa,
4786 		    px_args.port_actions_size);
4787 #if CONFIG_PERSONAS
4788 		kfree_data(imgp->ip_px_persona,
4789 		    px_args.persona_info_size);
4790 #endif
4791 		kfree_data(imgp->ip_px_pcred_info,
4792 		    px_args.posix_cred_info_size);
4793 
4794 		if (subsystem_root_path != NULL) {
4795 			zfree(ZV_NAMEI, subsystem_root_path);
4796 		}
4797 #if CONFIG_MACF
4798 		struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
4799 		kfree_data(px_s->array, px_args.mac_extensions_size);
4800 		kfree_data(px_s->data, (vm_size_t)px_s->datalen);
4801 
4802 		if (imgp->ip_execlabelp) {
4803 			mac_cred_label_free(imgp->ip_execlabelp);
4804 			imgp->ip_execlabelp = NULL;
4805 		}
4806 		if (imgp->ip_scriptlabelp) {
4807 			mac_vnode_label_free(imgp->ip_scriptlabelp);
4808 			imgp->ip_scriptlabelp = NULL;
4809 		}
4810 		if (imgp->ip_cs_error != OS_REASON_NULL) {
4811 			os_reason_free(imgp->ip_cs_error);
4812 			imgp->ip_cs_error = OS_REASON_NULL;
4813 		}
4814 		if (imgp->ip_inherited_shared_region_id != NULL) {
4815 			kfree_data(imgp->ip_inherited_shared_region_id,
4816 			    strlen(imgp->ip_inherited_shared_region_id) + 1);
4817 			imgp->ip_inherited_shared_region_id = NULL;
4818 		}
4819 #endif
4820 	}
4821 
4822 #if CONFIG_DTRACE
4823 	if (spawn_no_exec) {
4824 		/*
4825 		 * In the original DTrace reference implementation,
4826 		 * posix_spawn() was a libc routine that just
4827 		 * did vfork(2) then exec(2).  Thus the proc::: probes
4828 		 * are very fork/exec oriented.  The details of this
4829 		 * in-kernel implementation of posix_spawn() is different
4830 		 * (while producing the same process-observable effects)
4831 		 * particularly w.r.t. errors, and which thread/process
4832 		 * is constructing what on behalf of whom.
4833 		 */
4834 		if (error) {
4835 			DTRACE_PROC1(spawn__failure, int, error);
4836 		} else {
4837 			DTRACE_PROC(spawn__success);
4838 			/*
4839 			 * Some DTrace scripts, e.g. newproc.d in
4840 			 * /usr/bin, rely on the the 'exec-success'
4841 			 * probe being fired in the child after the
4842 			 * new process image has been constructed
4843 			 * in order to determine the associated pid.
4844 			 *
4845 			 * So, even though the parent built the image
4846 			 * here, for compatibility, mark the new thread
4847 			 * so 'exec-success' fires on it as it leaves
4848 			 * the kernel.
4849 			 */
4850 			dtrace_thread_didexec(imgp->ip_new_thread);
4851 		}
4852 	} else {
4853 		if (error) {
4854 			DTRACE_PROC1(exec__failure, int, error);
4855 		} else {
4856 			dtrace_thread_didexec(imgp->ip_new_thread);
4857 		}
4858 	}
4859 
4860 	if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4861 		(*dtrace_proc_waitfor_hook)(p);
4862 	}
4863 #endif
4864 
4865 #if CONFIG_AUDIT
4866 	if (!error && AUDIT_ENABLED() && p) {
4867 		/* Add the CDHash of the new process to the audit record */
4868 		uint8_t *cdhash = cs_get_cdhash(p);
4869 		if (cdhash) {
4870 			AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4871 		}
4872 	}
4873 #endif
4874 
4875 	/* terminate the new task if exec failed  */
4876 	if (new_task != NULL && task_is_exec_copy(new_task)) {
4877 		task_terminate_internal(new_task);
4878 	}
4879 
4880 	if (exec_failure_reason && !spawn_no_exec) {
4881 		psignal_with_reason(p, SIGKILL, exec_failure_reason);
4882 		exec_failure_reason = NULL;
4883 	}
4884 
4885 	/* Return to both the parent and the child? */
4886 	if (imgp != NULL && spawn_no_exec) {
4887 		/*
4888 		 * If the parent wants the pid, copy it out
4889 		 */
4890 		if (error == 0 && pid != USER_ADDR_NULL) {
4891 			_Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
4892 			bool aligned = (pid & 3) == 0;
4893 			if (aligned) {
4894 				(void)copyout_atomic32(proc_getpid(p), pid);
4895 			} else {
4896 				(void)suword(pid, proc_getpid(p));
4897 			}
4898 		}
4899 		retval[0] = error;
4900 
4901 		/*
4902 		 * If we had an error, perform an internal reap ; this is
4903 		 * entirely safe, as we have a real process backing us.
4904 		 */
4905 		if (error) {
4906 			proc_list_lock();
4907 			p->p_listflag |= P_LIST_DEADPARENT;
4908 			proc_list_unlock();
4909 			proc_lock(p);
4910 			/* make sure no one else has killed it off... */
4911 			if (p->p_stat != SZOMB && p->exit_thread == NULL) {
4912 				p->exit_thread = current_thread();
4913 				p->p_posix_spawn_failed = true;
4914 				proc_unlock(p);
4915 				exit1(p, 1, (int *)NULL);
4916 			} else {
4917 				/* someone is doing it for us; just skip it */
4918 				proc_unlock(p);
4919 			}
4920 		}
4921 	}
4922 
4923 	/*
4924 	 * Do not terminate the current task, if proc_exec_switch_task did not
4925 	 * switch the tasks, terminating the current task without the switch would
4926 	 * result in loosing the SIGKILL status.
4927 	 */
4928 	if (task_did_exec(old_task)) {
4929 		/* Terminate the current task, since exec will start in new task */
4930 		task_terminate_internal(old_task);
4931 	}
4932 
4933 	/* Release the thread ref returned by cloneproc/fork1 */
4934 	if (imgp != NULL && imgp->ip_new_thread) {
4935 		/* clear the exec complete flag if there is an error before point of no-return */
4936 		uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
4937 		if (!spawn_no_exec && !exec_done && error != 0) {
4938 			clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
4939 		}
4940 		/* wake up the new thread */
4941 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
4942 		thread_deallocate(imgp->ip_new_thread);
4943 		imgp->ip_new_thread = NULL;
4944 	}
4945 
4946 	/* Release the ref returned by cloneproc/fork1 */
4947 	if (new_task) {
4948 		task_deallocate(new_task);
4949 		new_task = NULL;
4950 	}
4951 
4952 	if (should_release_proc_ref) {
4953 		proc_rele(p);
4954 	}
4955 
4956 	kfree_type(typeof(*__spawn_data), __spawn_data);
4957 
4958 	if (inherit != NULL) {
4959 		ipc_importance_release(inherit);
4960 	}
4961 
4962 #if CONFIG_EXCLAVES
4963 	if (task_conclave_id != NULL) {
4964 		kfree_data(task_conclave_id, MAXCONCLAVENAME);
4965 	}
4966 #endif
4967 
4968 	assert(spawn_no_exec || exec_failure_reason == NULL);
4969 	return error;
4970 }
4971 
4972 /*
4973  * proc_exec_switch_task
4974  *
4975  * Parameters:  old_proc		proc before exec
4976  *		new_proc		proc after exec
4977  *		old_task		task before exec
4978  *		new_task		task after exec
4979  *		imgp			image params
4980  *		inherit			resulting importance linkage
4981  *
4982  * Returns: proc.
4983  *
4984  * Note: The function will switch proc in pid hash from old proc to new proc.
4985  * The switch needs to happen after draining all proc refs and inside
4986  * a proc list lock. In the case of failure to switch the proc, which
4987  * might happen if the process received a SIGKILL or jetsam killed it,
4988  * it will make sure that the new tasks terminates. User proc ref returned
4989  * to caller.
4990  *
4991  * This function is called after point of no return, in the case
4992  * failure to switch, it will terminate the new task and swallow the
4993  * error and let the terminated process complete exec and die.
4994  */
4995 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)4996 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)
4997 {
4998 	boolean_t task_active;
4999 	boolean_t proc_active;
5000 	boolean_t thread_active;
5001 	boolean_t reparent_traced_child = FALSE;
5002 	thread_t old_thread = current_thread();
5003 	thread_t new_thread = imgp->ip_new_thread;
5004 
5005 	thread_set_exec_promotion(old_thread);
5006 	old_proc = proc_refdrain_will_exec(old_proc);
5007 
5008 	new_proc = proc_refdrain_will_exec(new_proc);
5009 	/* extra proc ref returned to the caller */
5010 
5011 	assert(get_threadtask(new_thread) == new_task);
5012 	task_active = task_is_active(new_task);
5013 	proc_active = !(old_proc->p_lflag & P_LEXIT);
5014 
5015 	/* Check if the current thread is not aborted due to SIGKILL */
5016 	thread_active = thread_is_active(old_thread);
5017 
5018 	/*
5019 	 * Do not switch the proc if the new task or proc is already terminated
5020 	 * as a result of error in exec past point of no return
5021 	 */
5022 	if (proc_active && task_active && thread_active) {
5023 		uthread_t new_uthread = get_bsdthread_info(new_thread);
5024 		uthread_t old_uthread = current_uthread();
5025 
5026 		/* Clear dispatchqueue and workloop ast offset */
5027 		new_proc->p_dispatchqueue_offset = 0;
5028 		new_proc->p_dispatchqueue_serialno_offset = 0;
5029 		new_proc->p_dispatchqueue_label_offset = 0;
5030 		new_proc->p_return_to_kernel_offset = 0;
5031 		new_proc->p_pthread_wq_quantum_offset = 0;
5032 
5033 		/* If old_proc is session leader, change the leader to new proc */
5034 		session_replace_leader(old_proc, new_proc);
5035 
5036 		proc_lock(old_proc);
5037 
5038 		/* Copy the signal state, dtrace state and set bsd ast on new thread */
5039 		act_set_astbsd(new_thread);
5040 		new_uthread->uu_siglist |= old_uthread->uu_siglist;
5041 		new_uthread->uu_siglist |= old_proc->p_siglist;
5042 		new_uthread->uu_sigwait = old_uthread->uu_sigwait;
5043 		new_uthread->uu_sigmask = old_uthread->uu_sigmask;
5044 		new_uthread->uu_oldmask = old_uthread->uu_oldmask;
5045 		new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
5046 #if CONFIG_DTRACE
5047 		new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
5048 		new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
5049 		new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
5050 		assert(new_uthread->t_dtrace_scratch == NULL);
5051 		new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
5052 
5053 		old_uthread->t_dtrace_sig = 0;
5054 		old_uthread->t_dtrace_stop = 0;
5055 		old_uthread->t_dtrace_resumepid = 0;
5056 		old_uthread->t_dtrace_scratch = NULL;
5057 #endif
5058 
5059 #if CONFIG_PROC_UDATA_STORAGE
5060 		new_proc->p_user_data = old_proc->p_user_data;
5061 #endif /* CONFIG_PROC_UDATA_STORAGE */
5062 
5063 		/* Copy the resource accounting info */
5064 		thread_copy_resource_info(new_thread, current_thread());
5065 
5066 		/* Clear the exit reason and signal state on old thread */
5067 		old_uthread->uu_exit_reason = NULL;
5068 		old_uthread->uu_siglist = 0;
5069 
5070 		task_set_did_exec_flag(old_task);
5071 		task_clear_exec_copy_flag(new_task);
5072 
5073 		task_copy_fields_for_exec(new_task, old_task);
5074 
5075 		/*
5076 		 * Need to transfer pending watch port boosts to the new task
5077 		 * while still making sure that the old task remains in the
5078 		 * importance linkage. Create an importance linkage from old task
5079 		 * to new task, then switch the task importance base of old task
5080 		 * and new task. After the switch the port watch boost will be
5081 		 * boosting the new task and new task will be donating importance
5082 		 * to old task.
5083 		 */
5084 		*inherit = ipc_importance_exec_switch_task(old_task, new_task);
5085 
5086 		/* Transfer parent's ptrace state to child */
5087 		new_proc->p_lflag &= ~(P_LTRACED | P_LSIGEXC | P_LNOATTACH);
5088 		new_proc->p_lflag |= (old_proc->p_lflag & (P_LTRACED | P_LSIGEXC | P_LNOATTACH));
5089 		new_proc->p_oppid = old_proc->p_oppid;
5090 
5091 		if (old_proc->p_pptr != new_proc->p_pptr) {
5092 			reparent_traced_child = TRUE;
5093 			new_proc->p_lflag |= P_LTRACE_WAIT;
5094 		}
5095 
5096 		proc_unlock(old_proc);
5097 
5098 		/* Update the list of proc knotes */
5099 		proc_transfer_knotes(old_proc, new_proc);
5100 
5101 		/* Update the proc interval timers */
5102 		proc_inherit_itimers(old_proc, new_proc);
5103 
5104 		proc_list_lock();
5105 
5106 		/* Insert the new proc in child list of parent proc */
5107 		p_reparentallchildren(old_proc, new_proc);
5108 
5109 		/* Switch proc in pid hash */
5110 		phash_replace_locked(old_proc, new_proc);
5111 
5112 		/* Transfer the shadow flag to old proc */
5113 		os_atomic_andnot(&new_proc->p_refcount, P_REF_SHADOW, relaxed);
5114 		os_atomic_or(&old_proc->p_refcount, P_REF_SHADOW, relaxed);
5115 
5116 		/* Change init proc if launchd exec */
5117 		if (old_proc == initproc) {
5118 			/* Take the ref on new proc after proc_refwake_did_exec */
5119 			initproc = new_proc;
5120 			/* Drop the proc ref on old proc */
5121 			proc_rele(old_proc);
5122 		}
5123 
5124 		proc_list_unlock();
5125 #if CONFIG_EXCLAVES
5126 		if (task_inherit_conclave(old_task, new_task, imgp->ip_vp,
5127 		    (int64_t)imgp->ip_arch_offset) != KERN_SUCCESS) {
5128 			task_terminate_internal(new_task);
5129 		}
5130 #endif
5131 	} else {
5132 		task_terminate_internal(new_task);
5133 	}
5134 
5135 	proc_refwake_did_exec(new_proc);
5136 	proc_refwake_did_exec(old_proc);
5137 
5138 	/* Take a ref on initproc if it changed */
5139 	if (new_proc == initproc) {
5140 		initproc = proc_ref(new_proc, false);
5141 		assert(initproc != PROC_NULL);
5142 	}
5143 
5144 	thread_clear_exec_promotion(old_thread);
5145 	proc_rele(old_proc);
5146 
5147 	if (reparent_traced_child) {
5148 		proc_t pp = proc_parent(old_proc);
5149 		assert(pp != PROC_NULL);
5150 
5151 		proc_reparentlocked(new_proc, pp, 1, 0);
5152 		proc_rele(pp);
5153 
5154 		proc_lock(new_proc);
5155 		new_proc->p_lflag &= ~P_LTRACE_WAIT;
5156 		proc_unlock(new_proc);
5157 	}
5158 
5159 	return new_proc;
5160 }
5161 
5162 /*
5163  * execve
5164  *
5165  * Parameters:	uap->fname		File name to exec
5166  *		uap->argp		Argument list
5167  *		uap->envp		Environment list
5168  *
5169  * Returns:	0			Success
5170  *	__mac_execve:EINVAL		Invalid argument
5171  *	__mac_execve:ENOTSUP		Invalid argument
5172  *	__mac_execve:EACCES		Permission denied
5173  *	__mac_execve:EINTR		Interrupted function
5174  *	__mac_execve:ENOMEM		Not enough space
5175  *	__mac_execve:EFAULT		Bad address
5176  *	__mac_execve:ENAMETOOLONG	Filename too long
5177  *	__mac_execve:ENOEXEC		Executable file format error
5178  *	__mac_execve:ETXTBSY		Text file busy [misuse of error code]
5179  *	__mac_execve:???
5180  *
5181  * TODO:	Dynamic linker header address on stack is copied via suword()
5182  */
5183 /* ARGSUSED */
5184 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)5185 execve(proc_t p, struct execve_args *uap, int32_t *retval)
5186 {
5187 	struct __mac_execve_args muap;
5188 	int err;
5189 
5190 	memoryshot(DBG_VM_EXECVE, DBG_FUNC_NONE);
5191 
5192 	muap.fname = uap->fname;
5193 	muap.argp = uap->argp;
5194 	muap.envp = uap->envp;
5195 	muap.mac_p = USER_ADDR_NULL;
5196 	err = __mac_execve(p, &muap, retval);
5197 
5198 	return err;
5199 }
5200 
5201 /*
5202  * __mac_execve
5203  *
5204  * Parameters:	uap->fname		File name to exec
5205  *		uap->argp		Argument list
5206  *		uap->envp		Environment list
5207  *		uap->mac_p		MAC label supplied by caller
5208  *
5209  * Returns:	0			Success
5210  *		EINVAL			Invalid argument
5211  *		ENOTSUP			Not supported
5212  *		ENOEXEC			Executable file format error
5213  *	exec_activate_image:EINVAL	Invalid argument
5214  *	exec_activate_image:EACCES	Permission denied
5215  *	exec_activate_image:EINTR	Interrupted function
5216  *	exec_activate_image:ENOMEM	Not enough space
5217  *	exec_activate_image:EFAULT	Bad address
5218  *	exec_activate_image:ENAMETOOLONG	Filename too long
5219  *	exec_activate_image:ENOEXEC	Executable file format error
5220  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
5221  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
5222  *	exec_activate_image:???
5223  *	mac_execve_enter:???
5224  *
5225  * TODO:	Dynamic linker header address on stack is copied via suword()
5226  */
5227 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)5228 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
5229 {
5230 	struct image_params *imgp = NULL;
5231 	struct vnode_attr *vap = NULL;
5232 	struct vnode_attr *origvap = NULL;
5233 	int error;
5234 	int is_64 = IS_64BIT_PROCESS(p);
5235 	struct vfs_context context;
5236 	struct uthread  *uthread = NULL;
5237 	task_t old_task = current_task();
5238 	task_t new_task = NULL;
5239 	boolean_t should_release_proc_ref = FALSE;
5240 	boolean_t exec_done = FALSE;
5241 	void *inherit = NULL;
5242 	struct {
5243 		struct image_params imgp;
5244 		struct vnode_attr va;
5245 		struct vnode_attr origva;
5246 	} *__execve_data;
5247 
5248 	/* Allocate a big chunk for locals instead of using stack since these
5249 	 * structures a pretty big.
5250 	 */
5251 	__execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
5252 	if (__execve_data == NULL) {
5253 		error = ENOMEM;
5254 		goto exit_with_error;
5255 	}
5256 	imgp = &__execve_data->imgp;
5257 	vap = &__execve_data->va;
5258 	origvap = &__execve_data->origva;
5259 
5260 	/* Initialize the common data in the image_params structure */
5261 	imgp->ip_user_fname = uap->fname;
5262 	imgp->ip_user_argv = uap->argp;
5263 	imgp->ip_user_envv = uap->envp;
5264 	imgp->ip_vattr = vap;
5265 	imgp->ip_origvattr = origvap;
5266 	imgp->ip_vfs_context = &context;
5267 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
5268 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
5269 	imgp->ip_mac_return = 0;
5270 	imgp->ip_cs_error = OS_REASON_NULL;
5271 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
5272 	imgp->ip_subsystem_root_path = NULL;
5273 	uthread_set_exec_data(current_uthread(), imgp);
5274 
5275 #if CONFIG_MACF
5276 	if (uap->mac_p != USER_ADDR_NULL) {
5277 		error = mac_execve_enter(uap->mac_p, imgp);
5278 		if (error) {
5279 			goto exit_with_error;
5280 		}
5281 	}
5282 #endif
5283 	uthread = current_uthread();
5284 	{
5285 		imgp->ip_flags |= IMGPF_EXEC;
5286 
5287 		/* Adjust the user proc count */
5288 		(void)chgproccnt(kauth_getruid(), 1);
5289 		/*
5290 		 * For execve case, create a new proc, task and thread
5291 		 * but don't make the proc visible to userland. After
5292 		 * image activation, the new proc would take place of
5293 		 * the old proc in pid hash and other lists that make
5294 		 * the proc visible to the system.
5295 		 */
5296 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
5297 		/* task and thread ref returned by cloneproc */
5298 		if (imgp->ip_new_thread == NULL) {
5299 			(void)chgproccnt(kauth_getruid(), -1);
5300 			error = ENOMEM;
5301 			goto exit_with_error;
5302 		}
5303 
5304 		new_task = get_threadtask(imgp->ip_new_thread);
5305 	}
5306 
5307 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
5308 
5309 	context.vc_thread = imgp->ip_new_thread;
5310 	context.vc_ucred = kauth_cred_proc_ref(p);      /* XXX must NOT be kauth_cred_get() */
5311 
5312 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
5313 
5314 	proc_transend(p, 0);
5315 	proc_signalend(p, 0);
5316 
5317 
5318 	/*
5319 	 * Activate the image.
5320 	 * Warning: If activation failed after point of no return, it returns error
5321 	 * as 0 and pretends the call succeeded.
5322 	 */
5323 	error = exec_activate_image(imgp);
5324 	/* thread and task ref returned for vfexec case */
5325 
5326 	if (imgp->ip_new_thread != NULL) {
5327 		/*
5328 		 * task reference might be returned by exec_activate_image
5329 		 * for vfexec.
5330 		 */
5331 		new_task = get_threadtask(imgp->ip_new_thread);
5332 #if defined(HAS_APPLE_PAC)
5333 		ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5334 		ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5335 #endif
5336 	}
5337 
5338 	if (!error) {
5339 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
5340 		/* proc ref returned */
5341 		should_release_proc_ref = TRUE;
5342 	}
5343 
5344 	kauth_cred_unref(&context.vc_ucred);
5345 
5346 	if (!error) {
5347 		exec_done = TRUE;
5348 		assert(imgp->ip_new_thread != NULL);
5349 
5350 		exec_resettextvp(p, imgp);
5351 		/*
5352 		 * Enable new task IPC access if exec_activate_image() returned an
5353 		 * active task. (Checks active bit in ipc_task_enable() under lock).
5354 		 * Must enable after resettextvp so that task port policies are not evaluated
5355 		 * until the csblob in the textvp is accurately reflected.
5356 		 */
5357 		ipc_task_enable(new_task);
5358 		error = process_signature(p, imgp);
5359 	}
5360 
5361 #if defined(HAS_APPLE_PAC)
5362 	if (imgp->ip_new_thread && !error) {
5363 		ml_task_set_jop_pid_from_shared_region(new_task, imgp->ip_flags & IMGPF_NOJOP);
5364 		ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
5365 	}
5366 #endif /* defined(HAS_APPLE_PAC) */
5367 
5368 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
5369 	if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
5370 		proc_knote(p, NOTE_EXEC);
5371 	}
5372 
5373 	if (imgp->ip_vp != NULLVP) {
5374 		vnode_put(imgp->ip_vp);
5375 	}
5376 	if (imgp->ip_scriptvp != NULLVP) {
5377 		vnode_put(imgp->ip_scriptvp);
5378 	}
5379 	if (imgp->ip_free_map) {
5380 		/* Free the map after dropping iocount on vnode to avoid deadlock */
5381 		vm_map_deallocate(imgp->ip_free_map);
5382 	}
5383 	if (imgp->ip_strings) {
5384 		execargs_free(imgp);
5385 	}
5386 #if CONFIG_MACF
5387 	if (imgp->ip_execlabelp) {
5388 		mac_cred_label_free(imgp->ip_execlabelp);
5389 		imgp->ip_execlabelp = NULL;
5390 	}
5391 	if (imgp->ip_scriptlabelp) {
5392 		mac_vnode_label_free(imgp->ip_scriptlabelp);
5393 		imgp->ip_scriptlabelp = NULL;
5394 	}
5395 #endif
5396 	if (imgp->ip_cs_error != OS_REASON_NULL) {
5397 		os_reason_free(imgp->ip_cs_error);
5398 		imgp->ip_cs_error = OS_REASON_NULL;
5399 	}
5400 
5401 	if (!error) {
5402 		/*
5403 		 * We need to initialize the bank context behind the protection of
5404 		 * the proc_trans lock to prevent a race with exit. We can't do this during
5405 		 * exec_activate_image because task_bank_init checks entitlements that
5406 		 * aren't loaded until subsequent calls (including exec_resettextvp).
5407 		 */
5408 		error = proc_transstart(p, 0, 0);
5409 	}
5410 
5411 	if (!error) {
5412 		task_bank_init(new_task);
5413 		proc_transend(p, 0);
5414 
5415 		// Don't inherit crash behavior across exec, but preserve crash behavior from bootargs
5416 		p->p_crash_behavior = 0;
5417 		p->p_crash_behavior_deadline = 0;
5418 #if (DEVELOPMENT || DEBUG)
5419 		set_crash_behavior_from_bootarg(p);
5420 #endif
5421 
5422 #if __arm64__
5423 		proc_footprint_entitlement_hacks(p, new_task);
5424 #endif /* __arm64__ */
5425 
5426 #if XNU_TARGET_OS_OSX
5427 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
5428 			vm_map_single_jit(get_task_map(new_task));
5429 		}
5430 #endif /* XNU_TARGET_OS_OSX */
5431 
5432 		/* Sever any extant thread affinity */
5433 		thread_affinity_exec(current_thread());
5434 
5435 		/* Inherit task role from old task to new task for exec */
5436 		proc_inherit_task_role(new_task, old_task);
5437 
5438 		thread_t main_thread = imgp->ip_new_thread;
5439 
5440 		task_set_main_thread_qos(new_task, main_thread);
5441 
5442 #if __has_feature(ptrauth_calls)
5443 		task_set_pac_exception_fatal_flag(new_task);
5444 #endif /* __has_feature(ptrauth_calls) */
5445 		task_set_jit_exception_fatal_flag(new_task);
5446 
5447 #if CONFIG_ARCADE
5448 		/*
5449 		 * Check to see if we need to trigger an arcade upcall AST now
5450 		 * that the vnode has been reset on the task.
5451 		 */
5452 		arcade_prepare(new_task, imgp->ip_new_thread);
5453 #endif /* CONFIG_ARCADE */
5454 
5455 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
5456 
5457 		if (vm_darkwake_mode == TRUE) {
5458 			/*
5459 			 * This process is being launched when the system
5460 			 * is in darkwake. So mark it specially. This will
5461 			 * cause all its pages to be entered in the background Q.
5462 			 */
5463 			task_set_darkwake_mode(new_task, vm_darkwake_mode);
5464 		}
5465 
5466 #if CONFIG_DTRACE
5467 		dtrace_thread_didexec(imgp->ip_new_thread);
5468 
5469 		if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5470 			(*dtrace_proc_waitfor_hook)(p);
5471 		}
5472 #endif
5473 
5474 #if CONFIG_AUDIT
5475 		if (!error && AUDIT_ENABLED() && p) {
5476 			/* Add the CDHash of the new process to the audit record */
5477 			uint8_t *cdhash = cs_get_cdhash(p);
5478 			if (cdhash) {
5479 				AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5480 			}
5481 		}
5482 #endif
5483 	} else {
5484 		DTRACE_PROC1(exec__failure, int, error);
5485 	}
5486 
5487 exit_with_error:
5488 
5489 	/* terminate the new task it if exec failed  */
5490 	if (new_task != NULL && task_is_exec_copy(new_task)) {
5491 		task_terminate_internal(new_task);
5492 	}
5493 
5494 	if (imgp != NULL) {
5495 		/* Clear the initial wait on the thread transferring watchports */
5496 		if (imgp->ip_new_thread) {
5497 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
5498 		}
5499 
5500 		/* Transfer the watchport boost to new task */
5501 		if (!error) {
5502 			task_transfer_turnstile_watchports(old_task,
5503 			    new_task, imgp->ip_new_thread);
5504 		}
5505 		/*
5506 		 * Do not terminate the current task, if proc_exec_switch_task did not
5507 		 * switch the tasks, terminating the current task without the switch would
5508 		 * result in loosing the SIGKILL status.
5509 		 */
5510 		if (task_did_exec(old_task)) {
5511 			/* Terminate the current task, since exec will start in new task */
5512 			task_terminate_internal(old_task);
5513 		}
5514 
5515 		/* Release the thread ref returned by cloneproc */
5516 		if (imgp->ip_new_thread) {
5517 			/* clear the exec complete flag if there is an error before point of no-return */
5518 			uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5519 			if (!exec_done && error != 0) {
5520 				clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5521 			}
5522 			/* wake up the new exec thread */
5523 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5524 			thread_deallocate(imgp->ip_new_thread);
5525 			imgp->ip_new_thread = NULL;
5526 		}
5527 	}
5528 
5529 	/* Release the ref returned by fork_create_child */
5530 	if (new_task) {
5531 		task_deallocate(new_task);
5532 		new_task = NULL;
5533 	}
5534 
5535 	if (should_release_proc_ref) {
5536 		proc_rele(p);
5537 	}
5538 
5539 	uthread_set_exec_data(current_uthread(), NULL);
5540 	kfree_type(typeof(*__execve_data), __execve_data);
5541 
5542 	if (inherit != NULL) {
5543 		ipc_importance_release(inherit);
5544 	}
5545 
5546 	return error;
5547 }
5548 
5549 
5550 /*
5551  * copyinptr
5552  *
5553  * Description:	Copy a pointer in from user space to a user_addr_t in kernel
5554  *		space, based on 32/64 bitness of the user space
5555  *
5556  * Parameters:	froma			User space address
5557  *		toptr			Address of kernel space user_addr_t
5558  *		ptr_size		4/8, based on 'froma' address space
5559  *
5560  * Returns:	0			Success
5561  *		EFAULT			Bad 'froma'
5562  *
5563  * Implicit returns:
5564  *		*ptr_size		Modified
5565  */
5566 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)5567 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
5568 {
5569 	int error;
5570 
5571 	if (ptr_size == 4) {
5572 		/* 64 bit value containing 32 bit address */
5573 		unsigned int i = 0;
5574 
5575 		error = copyin(froma, &i, 4);
5576 		*toptr = CAST_USER_ADDR_T(i);   /* SAFE */
5577 	} else {
5578 		error = copyin(froma, toptr, 8);
5579 	}
5580 	return error;
5581 }
5582 
5583 
5584 /*
5585  * copyoutptr
5586  *
5587  * Description:	Copy a pointer out from a user_addr_t in kernel space to
5588  *		user space, based on 32/64 bitness of the user space
5589  *
5590  * Parameters:	ua			User space address to copy to
5591  *		ptr			Address of kernel space user_addr_t
5592  *		ptr_size		4/8, based on 'ua' address space
5593  *
5594  * Returns:	0			Success
5595  *		EFAULT			Bad 'ua'
5596  *
5597  */
5598 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)5599 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
5600 {
5601 	int error;
5602 
5603 	if (ptr_size == 4) {
5604 		/* 64 bit value containing 32 bit address */
5605 		unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua);   /* SAFE */
5606 
5607 		error = copyout(&i, ptr, 4);
5608 	} else {
5609 		error = copyout(&ua, ptr, 8);
5610 	}
5611 	return error;
5612 }
5613 
5614 
5615 /*
5616  * exec_copyout_strings
5617  *
5618  * Copy out the strings segment to user space.  The strings segment is put
5619  * on a preinitialized stack frame.
5620  *
5621  * Parameters:	struct image_params *	the image parameter block
5622  *		int *			a pointer to the stack offset variable
5623  *
5624  * Returns:	0			Success
5625  *		!0			Faiure: errno
5626  *
5627  * Implicit returns:
5628  *		(*stackp)		The stack offset, modified
5629  *
5630  * Note:	The strings segment layout is backward, from the beginning
5631  *		of the top of the stack to consume the minimal amount of
5632  *		space possible; the returned stack pointer points to the
5633  *		end of the area consumed (stacks grow downward).
5634  *
5635  *		argc is an int; arg[i] are pointers; env[i] are pointers;
5636  *		the 0's are (void *)NULL's
5637  *
5638  * The stack frame layout is:
5639  *
5640  *      +-------------+ <- p->user_stack
5641  *      |     16b     |
5642  *      +-------------+
5643  *      | STRING AREA |
5644  *      |      :      |
5645  *      |      :      |
5646  *      |      :      |
5647  *      +- -- -- -- --+
5648  *      |  PATH AREA  |
5649  *      +-------------+
5650  *      |      0      |
5651  *      +-------------+
5652  *      |  applev[n]  |
5653  *      +-------------+
5654  *             :
5655  *             :
5656  *      +-------------+
5657  *      |  applev[1]  |
5658  *      +-------------+
5659  *      | exec_path / |
5660  *      |  applev[0]  |
5661  *      +-------------+
5662  *      |      0      |
5663  *      +-------------+
5664  *      |    env[n]   |
5665  *      +-------------+
5666  *             :
5667  *             :
5668  *      +-------------+
5669  *      |    env[0]   |
5670  *      +-------------+
5671  *      |      0      |
5672  *      +-------------+
5673  *      | arg[argc-1] |
5674  *      +-------------+
5675  *             :
5676  *             :
5677  *      +-------------+
5678  *      |    arg[0]   |
5679  *      +-------------+
5680  *      |     argc    |
5681  * sp-> +-------------+
5682  *
5683  * Although technically a part of the STRING AREA, we treat the PATH AREA as
5684  * a separate entity.  This allows us to align the beginning of the PATH AREA
5685  * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
5686  * which preceed it on the stack are properly aligned.
5687  */
5688 __attribute__((noinline))
5689 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)5690 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
5691 {
5692 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5693 	int     ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5694 	int     ptr_area_size;
5695 	void *ptr_buffer_start, *ptr_buffer;
5696 	size_t string_size;
5697 
5698 	user_addr_t     string_area;    /* *argv[], *env[] */
5699 	user_addr_t     ptr_area;       /* argv[], env[], applev[] */
5700 	user_addr_t argc_area;  /* argc */
5701 	user_addr_t     stack;
5702 	int error;
5703 
5704 	unsigned i;
5705 	struct copyout_desc {
5706 		char    *start_string;
5707 		int             count;
5708 #if CONFIG_DTRACE
5709 		user_addr_t     *dtrace_cookie;
5710 #endif
5711 		boolean_t       null_term;
5712 	} descriptors[] = {
5713 		{
5714 			.start_string = imgp->ip_startargv,
5715 			.count = imgp->ip_argc,
5716 #if CONFIG_DTRACE
5717 			.dtrace_cookie = &p->p_dtrace_argv,
5718 #endif
5719 			.null_term = TRUE
5720 		},
5721 		{
5722 			.start_string = imgp->ip_endargv,
5723 			.count = imgp->ip_envc,
5724 #if CONFIG_DTRACE
5725 			.dtrace_cookie = &p->p_dtrace_envp,
5726 #endif
5727 			.null_term = TRUE
5728 		},
5729 		{
5730 			.start_string = imgp->ip_strings,
5731 			.count = 1,
5732 #if CONFIG_DTRACE
5733 			.dtrace_cookie = NULL,
5734 #endif
5735 			.null_term = FALSE
5736 		},
5737 		{
5738 			.start_string = imgp->ip_endenvv,
5739 			.count = imgp->ip_applec - 1, /* exec_path handled above */
5740 #if CONFIG_DTRACE
5741 			.dtrace_cookie = NULL,
5742 #endif
5743 			.null_term = TRUE
5744 		}
5745 	};
5746 
5747 	stack = *stackp;
5748 
5749 	/*
5750 	 * All previous contributors to the string area
5751 	 * should have aligned their sub-area
5752 	 */
5753 	if (imgp->ip_strspace % ptr_size != 0) {
5754 		error = EINVAL;
5755 		goto bad;
5756 	}
5757 
5758 	/* Grow the stack down for the strings we've been building up */
5759 	string_size = imgp->ip_strendp - imgp->ip_strings;
5760 	stack -= string_size;
5761 	string_area = stack;
5762 
5763 	/*
5764 	 * Need room for one pointer for each string, plus
5765 	 * one for the NULLs terminating the argv, envv, and apple areas.
5766 	 */
5767 	ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5768 	stack -= ptr_area_size;
5769 	ptr_area = stack;
5770 
5771 	/* We'll construct all the pointer arrays in our string buffer,
5772 	 * which we already know is aligned properly, and ip_argspace
5773 	 * was used to verify we have enough space.
5774 	 */
5775 	ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5776 
5777 	/*
5778 	 * Need room for pointer-aligned argc slot.
5779 	 */
5780 	stack -= ptr_size;
5781 	argc_area = stack;
5782 
5783 	/*
5784 	 * Record the size of the arguments area so that sysctl_procargs()
5785 	 * can return the argument area without having to parse the arguments.
5786 	 */
5787 	proc_lock(p);
5788 	p->p_argc = imgp->ip_argc;
5789 	p->p_argslen = (int)(*stackp - string_area);
5790 	proc_unlock(p);
5791 
5792 	/* Return the initial stack address: the location of argc */
5793 	*stackp = stack;
5794 
5795 	/*
5796 	 * Copy out the entire strings area.
5797 	 */
5798 	error = copyout(imgp->ip_strings, string_area,
5799 	    string_size);
5800 	if (error) {
5801 		goto bad;
5802 	}
5803 
5804 	for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
5805 		char *cur_string = descriptors[i].start_string;
5806 		int j;
5807 
5808 #if CONFIG_DTRACE
5809 		if (descriptors[i].dtrace_cookie) {
5810 			proc_lock(p);
5811 			*descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
5812 			proc_unlock(p);
5813 		}
5814 #endif /* CONFIG_DTRACE */
5815 
5816 		/*
5817 		 * For each segment (argv, envv, applev), copy as many pointers as requested
5818 		 * to our pointer buffer.
5819 		 */
5820 		for (j = 0; j < descriptors[i].count; j++) {
5821 			user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
5822 
5823 			/* Copy out the pointer to the current string. Alignment has been verified  */
5824 			if (ptr_size == 8) {
5825 				*(uint64_t *)ptr_buffer = (uint64_t)cur_address;
5826 			} else {
5827 				*(uint32_t *)ptr_buffer = (uint32_t)cur_address;
5828 			}
5829 
5830 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5831 			cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
5832 		}
5833 
5834 		if (descriptors[i].null_term) {
5835 			if (ptr_size == 8) {
5836 				*(uint64_t *)ptr_buffer = 0ULL;
5837 			} else {
5838 				*(uint32_t *)ptr_buffer = 0;
5839 			}
5840 
5841 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5842 		}
5843 	}
5844 
5845 	/*
5846 	 * Copy out all our pointer arrays in bulk.
5847 	 */
5848 	error = copyout(ptr_buffer_start, ptr_area,
5849 	    ptr_area_size);
5850 	if (error) {
5851 		goto bad;
5852 	}
5853 
5854 	/* argc (int32, stored in a ptr_size area) */
5855 	error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
5856 	if (error) {
5857 		goto bad;
5858 	}
5859 
5860 bad:
5861 	return error;
5862 }
5863 
5864 
5865 /*
5866  * exec_extract_strings
5867  *
5868  * Copy arguments and environment from user space into work area; we may
5869  * have already copied some early arguments into the work area, and if
5870  * so, any arguments opied in are appended to those already there.
5871  * This function is the primary manipulator of ip_argspace, since
5872  * these are the arguments the client of execve(2) knows about. After
5873  * each argv[]/envv[] string is copied, we charge the string length
5874  * and argv[]/envv[] pointer slot to ip_argspace, so that we can
5875  * full preflight the arg list size.
5876  *
5877  * Parameters:	struct image_params *	the image parameter block
5878  *
5879  * Returns:	0			Success
5880  *		!0			Failure: errno
5881  *
5882  * Implicit returns;
5883  *		(imgp->ip_argc)		Count of arguments, updated
5884  *		(imgp->ip_envc)		Count of environment strings, updated
5885  *		(imgp->ip_argspace)	Count of remaining of NCARGS
5886  *		(imgp->ip_interp_buffer)	Interpreter and args (mutated in place)
5887  *
5888  *
5889  * Note:	The argument and environment vectors are user space pointers
5890  *		to arrays of user space pointers.
5891  */
5892 __attribute__((noinline))
5893 static int
exec_extract_strings(struct image_params * imgp)5894 exec_extract_strings(struct image_params *imgp)
5895 {
5896 	int error = 0;
5897 	int     ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
5898 	int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5899 	user_addr_t     argv = imgp->ip_user_argv;
5900 	user_addr_t     envv = imgp->ip_user_envv;
5901 
5902 	/*
5903 	 * Adjust space reserved for the path name by however much padding it
5904 	 * needs. Doing this here since we didn't know if this would be a 32-
5905 	 * or 64-bit process back in exec_save_path.
5906 	 */
5907 	while (imgp->ip_strspace % new_ptr_size != 0) {
5908 		*imgp->ip_strendp++ = '\0';
5909 		imgp->ip_strspace--;
5910 		/* imgp->ip_argspace--; not counted towards exec args total */
5911 	}
5912 
5913 	/*
5914 	 * From now on, we start attributing string space to ip_argspace
5915 	 */
5916 	imgp->ip_startargv = imgp->ip_strendp;
5917 	imgp->ip_argc = 0;
5918 
5919 	if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
5920 		user_addr_t     arg;
5921 		char *argstart, *ch;
5922 
5923 		/* First, the arguments in the "#!" string are tokenized and extracted. */
5924 		argstart = imgp->ip_interp_buffer;
5925 		while (argstart) {
5926 			ch = argstart;
5927 			while (*ch && !IS_WHITESPACE(*ch)) {
5928 				ch++;
5929 			}
5930 
5931 			if (*ch == '\0') {
5932 				/* last argument, no need to NUL-terminate */
5933 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5934 				argstart = NULL;
5935 			} else {
5936 				/* NUL-terminate */
5937 				*ch = '\0';
5938 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5939 
5940 				/*
5941 				 * Find the next string. We know spaces at the end of the string have already
5942 				 * been stripped.
5943 				 */
5944 				argstart = ch + 1;
5945 				while (IS_WHITESPACE(*argstart)) {
5946 					argstart++;
5947 				}
5948 			}
5949 
5950 			/* Error-check, regardless of whether this is the last interpreter arg or not */
5951 			if (error) {
5952 				goto bad;
5953 			}
5954 			if (imgp->ip_argspace < new_ptr_size) {
5955 				error = E2BIG;
5956 				goto bad;
5957 			}
5958 			imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5959 			imgp->ip_argc++;
5960 		}
5961 
5962 		if (argv != 0LL) {
5963 			/*
5964 			 * If we are running an interpreter, replace the av[0] that was
5965 			 * passed to execve() with the path name that was
5966 			 * passed to execve() for interpreters which do not use the PATH
5967 			 * to locate their script arguments.
5968 			 */
5969 			error = copyinptr(argv, &arg, ptr_size);
5970 			if (error) {
5971 				goto bad;
5972 			}
5973 			if (arg != 0LL) {
5974 				argv += ptr_size; /* consume without using */
5975 			}
5976 		}
5977 
5978 		if (imgp->ip_interp_sugid_fd != -1) {
5979 			char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
5980 			snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
5981 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
5982 		} else {
5983 			error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
5984 		}
5985 
5986 		if (error) {
5987 			goto bad;
5988 		}
5989 		if (imgp->ip_argspace < new_ptr_size) {
5990 			error = E2BIG;
5991 			goto bad;
5992 		}
5993 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5994 		imgp->ip_argc++;
5995 	}
5996 
5997 	while (argv != 0LL) {
5998 		user_addr_t     arg;
5999 
6000 		error = copyinptr(argv, &arg, ptr_size);
6001 		if (error) {
6002 			goto bad;
6003 		}
6004 
6005 		if (arg == 0LL) {
6006 			break;
6007 		}
6008 
6009 		argv += ptr_size;
6010 
6011 		/*
6012 		 * av[n...] = arg[n]
6013 		 */
6014 		error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
6015 		if (error) {
6016 			goto bad;
6017 		}
6018 		if (imgp->ip_argspace < new_ptr_size) {
6019 			error = E2BIG;
6020 			goto bad;
6021 		}
6022 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6023 		imgp->ip_argc++;
6024 	}
6025 
6026 	/* Save space for argv[] NULL terminator */
6027 	if (imgp->ip_argspace < new_ptr_size) {
6028 		error = E2BIG;
6029 		goto bad;
6030 	}
6031 	imgp->ip_argspace -= new_ptr_size;
6032 
6033 	/* Note where the args ends and env begins. */
6034 	imgp->ip_endargv = imgp->ip_strendp;
6035 	imgp->ip_envc = 0;
6036 
6037 	/* Now, get the environment */
6038 	while (envv != 0LL) {
6039 		user_addr_t     env;
6040 
6041 		error = copyinptr(envv, &env, ptr_size);
6042 		if (error) {
6043 			goto bad;
6044 		}
6045 
6046 		envv += ptr_size;
6047 		if (env == 0LL) {
6048 			break;
6049 		}
6050 		/*
6051 		 * av[n...] = env[n]
6052 		 */
6053 		error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
6054 		if (error) {
6055 			goto bad;
6056 		}
6057 		if (imgp->ip_argspace < new_ptr_size) {
6058 			error = E2BIG;
6059 			goto bad;
6060 		}
6061 		imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
6062 		imgp->ip_envc++;
6063 	}
6064 
6065 	/* Save space for envv[] NULL terminator */
6066 	if (imgp->ip_argspace < new_ptr_size) {
6067 		error = E2BIG;
6068 		goto bad;
6069 	}
6070 	imgp->ip_argspace -= new_ptr_size;
6071 
6072 	/* Align the tail of the combined argv+envv area */
6073 	while (imgp->ip_strspace % new_ptr_size != 0) {
6074 		if (imgp->ip_argspace < 1) {
6075 			error = E2BIG;
6076 			goto bad;
6077 		}
6078 		*imgp->ip_strendp++ = '\0';
6079 		imgp->ip_strspace--;
6080 		imgp->ip_argspace--;
6081 	}
6082 
6083 	/* Note where the envv ends and applev begins. */
6084 	imgp->ip_endenvv = imgp->ip_strendp;
6085 
6086 	/*
6087 	 * From now on, we are no longer charging argument
6088 	 * space to ip_argspace.
6089 	 */
6090 
6091 bad:
6092 	return error;
6093 }
6094 
6095 /*
6096  * Libc has an 8-element array set up for stack guard values.  It only fills
6097  * in one of those entries, and both gcc and llvm seem to use only a single
6098  * 8-byte guard.  Until somebody needs more than an 8-byte guard value, don't
6099  * do the work to construct them.
6100  */
6101 #define GUARD_VALUES 1
6102 #define GUARD_KEY "stack_guard="
6103 
6104 /*
6105  * System malloc needs some entropy when it is initialized.
6106  */
6107 #define ENTROPY_VALUES 2
6108 #define ENTROPY_KEY "malloc_entropy="
6109 
6110 /*
6111  * libplatform needs a random pointer-obfuscation value when it is initialized.
6112  */
6113 #define PTR_MUNGE_VALUES 1
6114 #define PTR_MUNGE_KEY "ptr_munge="
6115 
6116 /*
6117  * System malloc engages nanozone for UIAPP.
6118  */
6119 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
6120 
6121 /*
6122  * Used to pass experiment flags up to libmalloc.
6123  */
6124 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
6125 
6126 /*
6127  * Passes information about hardened runtime entitlements to libsystem/libmalloc
6128  */
6129 #define HARDENED_RUNTIME_KEY "HardenedRuntime="
6130 
6131 #define PFZ_KEY "pfz="
6132 extern user32_addr_t commpage_text32_location;
6133 extern user64_addr_t commpage_text64_location;
6134 
6135 extern uuid_string_t bootsessionuuid_string;
6136 static TUNABLE(uint32_t, exe_boothash_salt, "exe_boothash_salt", 0);
6137 
6138 __startup_func
6139 static void
exe_boothash_salt_generate(void)6140 exe_boothash_salt_generate(void)
6141 {
6142 	if (!PE_parse_boot_argn("exe_boothash_salt", NULL, 0)) {
6143 		read_random(&exe_boothash_salt, sizeof(exe_boothash_salt));
6144 	}
6145 }
6146 STARTUP(EARLY_BOOT, STARTUP_RANK_MIDDLE, exe_boothash_salt_generate);
6147 
6148 
6149 #define MAIN_STACK_VALUES 4
6150 #define MAIN_STACK_KEY "main_stack="
6151 
6152 #define FSID_KEY "executable_file="
6153 #define DYLD_FSID_KEY "dyld_file="
6154 #define CDHASH_KEY "executable_cdhash="
6155 #define DYLD_FLAGS_KEY "dyld_flags="
6156 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
6157 #define APP_BOOT_SESSION_KEY "executable_boothash="
6158 #if __has_feature(ptrauth_calls)
6159 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
6160 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
6161 #endif /* __has_feature(ptrauth_calls) */
6162 #define MAIN_TH_PORT_KEY "th_port="
6163 
6164 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
6165 
6166 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
6167 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
6168 
6169 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6170 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
6171 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6172 
6173 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)6174 exec_add_entropy_key(struct image_params *imgp,
6175     const char *key,
6176     int values,
6177     boolean_t embedNUL)
6178 {
6179 	const int limit = 8;
6180 	uint64_t entropy[limit];
6181 	char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
6182 	if (values > limit) {
6183 		values = limit;
6184 	}
6185 
6186 	read_random(entropy, sizeof(entropy[0]) * values);
6187 
6188 	if (embedNUL) {
6189 		entropy[0] &= ~(0xffull << 8);
6190 	}
6191 
6192 	int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
6193 	size_t remaining = sizeof(str) - len;
6194 	for (int i = 1; i < values && remaining > 0; ++i) {
6195 		size_t start = sizeof(str) - remaining;
6196 		len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
6197 		remaining -= len;
6198 	}
6199 
6200 	return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
6201 }
6202 
6203 /*
6204  * Build up the contents of the apple[] string vector
6205  */
6206 #if (DEVELOPMENT || DEBUG)
6207 extern uint64_t dyld_flags;
6208 #endif
6209 
6210 #if __has_feature(ptrauth_calls)
6211 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)6212 is_arm64e_running_as_arm64(const struct image_params *imgp)
6213 {
6214 	return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
6215 	       (imgp->ip_flags & IMGPF_NOJOP);
6216 }
6217 #endif /* __has_feature(ptrauth_calls) */
6218 
6219 _Atomic uint64_t libmalloc_experiment_factors = 0;
6220 
6221 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result)6222 exec_add_apple_strings(struct image_params *imgp,
6223     const load_result_t *load_result)
6224 {
6225 	int error;
6226 	int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6227 	thread_t new_thread;
6228 	ipc_port_t sright;
6229 	uint64_t local_experiment_factors = 0;
6230 
6231 	/* exec_save_path stored the first string */
6232 	imgp->ip_applec = 1;
6233 
6234 	/* adding the pfz string */
6235 	{
6236 		char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
6237 
6238 		if (img_ptr_size == 8) {
6239 			__assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
6240 			assert(ret < sizeof(pfz_string));
6241 		} else {
6242 			snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
6243 		}
6244 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
6245 		if (error) {
6246 			printf("Failed to add the pfz string with error %d\n", error);
6247 			goto bad;
6248 		}
6249 		imgp->ip_applec++;
6250 	}
6251 
6252 	/* adding the NANO_ENGAGE_KEY key */
6253 	if (imgp->ip_px_sa) {
6254 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6255 		int proc_flags = psa->psa_flags;
6256 
6257 		if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
6258 			const char *nano_string = NANO_ENGAGE_KEY;
6259 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
6260 			if (error) {
6261 				goto bad;
6262 			}
6263 			imgp->ip_applec++;
6264 		}
6265 	}
6266 
6267 	/*
6268 	 * Supply libc with a collection of random values to use when
6269 	 * implementing -fstack-protector.
6270 	 *
6271 	 * (The first random string always contains an embedded NUL so that
6272 	 * __stack_chk_guard also protects against C string vulnerabilities)
6273 	 */
6274 	error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
6275 	if (error) {
6276 		goto bad;
6277 	}
6278 	imgp->ip_applec++;
6279 
6280 	/*
6281 	 * Supply libc with entropy for system malloc.
6282 	 */
6283 	error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
6284 	if (error) {
6285 		goto bad;
6286 	}
6287 	imgp->ip_applec++;
6288 
6289 	/*
6290 	 * Supply libpthread & libplatform with a random value to use for pointer
6291 	 * obfuscation.
6292 	 */
6293 	error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
6294 	if (error) {
6295 		goto bad;
6296 	}
6297 	imgp->ip_applec++;
6298 
6299 	/*
6300 	 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
6301 	 * stack if it was allocated by the kernel.
6302 	 *
6303 	 * The guard page is not included in this stack size as libpthread
6304 	 * expects to add it back in after receiving this value.
6305 	 */
6306 	if (load_result->unixproc) {
6307 		char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
6308 		snprintf(stack_string, sizeof(stack_string),
6309 		    MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
6310 		    (uint64_t)load_result->user_stack,
6311 		    (uint64_t)load_result->user_stack_size,
6312 		    (uint64_t)load_result->user_stack_alloc,
6313 		    (uint64_t)load_result->user_stack_alloc_size);
6314 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
6315 		if (error) {
6316 			goto bad;
6317 		}
6318 		imgp->ip_applec++;
6319 	}
6320 
6321 	if (imgp->ip_vattr) {
6322 		uint64_t fsid    = vnode_get_va_fsid(imgp->ip_vattr);
6323 		uint64_t fsobjid = imgp->ip_vattr->va_fileid;
6324 
6325 		char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6326 		snprintf(fsid_string, sizeof(fsid_string),
6327 		    FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
6328 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6329 		if (error) {
6330 			goto bad;
6331 		}
6332 		imgp->ip_applec++;
6333 	}
6334 
6335 	if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
6336 		char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6337 		snprintf(fsid_string, sizeof(fsid_string),
6338 		    DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
6339 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6340 		if (error) {
6341 			goto bad;
6342 		}
6343 		imgp->ip_applec++;
6344 	}
6345 
6346 	uint8_t cdhash[SHA1_RESULTLEN];
6347 	int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash);
6348 	if (cdhash_errror == 0) {
6349 		char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
6350 		strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
6351 		char *p = hash_string + sizeof(CDHASH_KEY) - 1;
6352 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6353 			snprintf(p, 3, "%02x", (int) cdhash[i]);
6354 			p += 2;
6355 		}
6356 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
6357 		if (error) {
6358 			goto bad;
6359 		}
6360 		imgp->ip_applec++;
6361 
6362 		/* hash together cd-hash and boot-session-uuid */
6363 		uint8_t sha_digest[SHA256_DIGEST_LENGTH];
6364 		SHA256_CTX sha_ctx;
6365 		SHA256_Init(&sha_ctx);
6366 		SHA256_Update(&sha_ctx, &exe_boothash_salt, sizeof(exe_boothash_salt));
6367 		SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
6368 		SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
6369 		SHA256_Final(sha_digest, &sha_ctx);
6370 		char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
6371 		strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
6372 		char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
6373 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6374 			snprintf(s, 3, "%02x", (int) sha_digest[i]);
6375 			s += 2;
6376 		}
6377 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
6378 		if (error) {
6379 			goto bad;
6380 		}
6381 		imgp->ip_applec++;
6382 	}
6383 #if (DEVELOPMENT || DEBUG)
6384 	if (dyld_flags) {
6385 		char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
6386 		snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
6387 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
6388 		if (error) {
6389 			goto bad;
6390 		}
6391 		imgp->ip_applec++;
6392 	}
6393 #endif
6394 	if (imgp->ip_subsystem_root_path) {
6395 		size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
6396 		char subsystem_root_path_string[buffer_len];
6397 		int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
6398 
6399 		if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
6400 			error = ENAMETOOLONG;
6401 			goto bad;
6402 		}
6403 
6404 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
6405 		if (error) {
6406 			goto bad;
6407 		}
6408 
6409 		imgp->ip_applec++;
6410 	}
6411 #if __has_feature(ptrauth_calls)
6412 	if (is_arm64e_running_as_arm64(imgp)) {
6413 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
6414 		if (error) {
6415 			goto bad;
6416 		}
6417 
6418 		imgp->ip_applec++;
6419 	}
6420 #endif /* __has_feature(ptrauth_calls) */
6421 
6422 
6423 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
6424 	{
6425 		char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
6426 		strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
6427 		bool allowAll = bootarg_arm64e_preview_abi;
6428 		strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
6429 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
6430 		if (error) {
6431 			goto bad;
6432 		}
6433 
6434 		imgp->ip_applec++;
6435 	}
6436 #endif
6437 	/*
6438 	 * Add main thread mach port name
6439 	 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
6440 	 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
6441 	 * against libpthread.
6442 	 */
6443 	if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
6444 		thread_reference(new_thread);
6445 		sright = convert_thread_to_port_pinned(new_thread);
6446 		task_t new_task = get_threadtask(new_thread);
6447 		mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
6448 		char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
6449 		snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
6450 
6451 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
6452 		if (error) {
6453 			goto bad;
6454 		}
6455 		imgp->ip_applec++;
6456 	}
6457 
6458 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6459 	if (imgp->ip_px_sa != NULL) {
6460 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6461 		if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
6462 			const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
6463 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
6464 			if (error) {
6465 				goto bad;
6466 			}
6467 			imgp->ip_applec++;
6468 		}
6469 	}
6470 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6471 
6472 	/* adding the libmalloc experiment string */
6473 	local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
6474 	if (__improbable(local_experiment_factors != 0)) {
6475 		char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
6476 
6477 		snprintf(
6478 			libmalloc_experiment_factors_string,
6479 			sizeof(libmalloc_experiment_factors_string),
6480 			LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
6481 			local_experiment_factors);
6482 		error = exec_add_user_string(
6483 			imgp,
6484 			CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
6485 			UIO_SYSSPACE,
6486 			FALSE);
6487 		if (error) {
6488 			printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
6489 			goto bad;
6490 		}
6491 		imgp->ip_applec++;
6492 	}
6493 
6494 
6495 	/* tell dyld that it can leverage hardware for its read-only/read-write trusted path */
6496 	if (imgp->ip_flags & IMGPF_HW_TPRO) {
6497 		const char *dyld_hw_tpro = "dyld_hw_tpro=1";
6498 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_hw_tpro), UIO_SYSSPACE, FALSE);
6499 		if (error) {
6500 			printf("Failed to add dyld hw tpro setting with error %d\n", error);
6501 			goto bad;
6502 		}
6503 
6504 		imgp->ip_applec++;
6505 
6506 	}
6507 
6508 	if (load_result->hardened_runtime_binary) {
6509 		const size_t HR_STRING_SIZE = sizeof(HARDENED_RUNTIME_KEY) + HR_FLAGS_NUM_NIBBLES + 2 + 1;
6510 		char hardened_runtime[HR_STRING_SIZE];
6511 		snprintf(hardened_runtime, HR_STRING_SIZE, HARDENED_RUNTIME_KEY"0x%x", load_result->hardened_runtime_binary);
6512 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hardened_runtime), UIO_SYSSPACE, FALSE);
6513 		if (error) {
6514 			printf("Failed to add hardened runtime flag with error %d\n", error);
6515 			goto bad;
6516 		}
6517 		imgp->ip_applec++;
6518 	}
6519 	/* Align the tail of the combined applev area */
6520 	while (imgp->ip_strspace % img_ptr_size != 0) {
6521 		*imgp->ip_strendp++ = '\0';
6522 		imgp->ip_strspace--;
6523 	}
6524 
6525 bad:
6526 	return error;
6527 }
6528 
6529 /*
6530  * exec_check_permissions
6531  *
6532  * Description:	Verify that the file that is being attempted to be executed
6533  *		is in fact allowed to be executed based on it POSIX file
6534  *		permissions and other access control criteria
6535  *
6536  * Parameters:	struct image_params *	the image parameter block
6537  *
6538  * Returns:	0			Success
6539  *		EACCES			Permission denied
6540  *		ENOEXEC			Executable file format error
6541  *		ETXTBSY			Text file busy [misuse of error code]
6542  *	vnode_getattr:???
6543  *	vnode_authorize:???
6544  */
6545 static int
exec_check_permissions(struct image_params * imgp)6546 exec_check_permissions(struct image_params *imgp)
6547 {
6548 	struct vnode *vp = imgp->ip_vp;
6549 	struct vnode_attr *vap = imgp->ip_vattr;
6550 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6551 	int error;
6552 	kauth_action_t action;
6553 
6554 	/* Only allow execution of regular files */
6555 	if (!vnode_isreg(vp)) {
6556 		return EACCES;
6557 	}
6558 
6559 	/* Get the file attributes that we will be using here and elsewhere */
6560 	VATTR_INIT(vap);
6561 	VATTR_WANTED(vap, va_uid);
6562 	VATTR_WANTED(vap, va_gid);
6563 	VATTR_WANTED(vap, va_mode);
6564 	VATTR_WANTED(vap, va_fsid);
6565 	VATTR_WANTED(vap, va_fsid64);
6566 	VATTR_WANTED(vap, va_fileid);
6567 	VATTR_WANTED(vap, va_data_size);
6568 	if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
6569 		return error;
6570 	}
6571 
6572 	/*
6573 	 * Ensure that at least one execute bit is on - otherwise root
6574 	 * will always succeed, and we don't want to happen unless the
6575 	 * file really is executable.
6576 	 */
6577 	if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
6578 		return EACCES;
6579 	}
6580 
6581 	/* Disallow zero length files */
6582 	if (vap->va_data_size == 0) {
6583 		return ENOEXEC;
6584 	}
6585 
6586 	imgp->ip_arch_offset = (user_size_t)0;
6587 #if __LP64__
6588 	imgp->ip_arch_size = vap->va_data_size;
6589 #else
6590 	if (vap->va_data_size > UINT32_MAX) {
6591 		return ENOEXEC;
6592 	}
6593 	imgp->ip_arch_size = (user_size_t)vap->va_data_size;
6594 #endif
6595 
6596 	/* Disable setuid-ness for traced programs or if MNT_NOSUID */
6597 	if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
6598 		vap->va_mode &= ~(VSUID | VSGID);
6599 	}
6600 
6601 	/*
6602 	 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
6603 	 * flags for setuid/setgid binaries.
6604 	 */
6605 	if (vap->va_mode & (VSUID | VSGID)) {
6606 		imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
6607 	}
6608 
6609 #if CONFIG_MACF
6610 	error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
6611 	if (error) {
6612 		return error;
6613 	}
6614 #endif
6615 
6616 	/* Check for execute permission */
6617 	action = KAUTH_VNODE_EXECUTE;
6618 	/* Traced images must also be readable */
6619 	if (p->p_lflag & P_LTRACED) {
6620 		action |= KAUTH_VNODE_READ_DATA;
6621 	}
6622 	if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
6623 		return error;
6624 	}
6625 
6626 #if 0
6627 	/* Don't let it run if anyone had it open for writing */
6628 	vnode_lock(vp);
6629 	if (vp->v_writecount) {
6630 		panic("going to return ETXTBSY %x", vp);
6631 		vnode_unlock(vp);
6632 		return ETXTBSY;
6633 	}
6634 	vnode_unlock(vp);
6635 #endif
6636 
6637 	/* XXX May want to indicate to underlying FS that vnode is open */
6638 
6639 	return error;
6640 }
6641 
6642 
6643 /*
6644  * exec_handle_sugid
6645  *
6646  * Initially clear the P_SUGID in the process flags; if an SUGID process is
6647  * exec'ing a non-SUGID image, then  this is the point of no return.
6648  *
6649  * If the image being activated is SUGID, then replace the credential with a
6650  * copy, disable tracing (unless the tracing process is root), reset the
6651  * mach task port to revoke it, set the P_SUGID bit,
6652  *
6653  * If the saved user and group ID will be changing, then make sure it happens
6654  * to a new credential, rather than a shared one.
6655  *
6656  * Set the security token (this is probably obsolete, given that the token
6657  * should not technically be separate from the credential itself).
6658  *
6659  * Parameters:	struct image_params *	the image parameter block
6660  *
6661  * Returns:	void			No failure indication
6662  *
6663  * Implicit returns:
6664  *		<process credential>	Potentially modified/replaced
6665  *		<task port>		Potentially revoked
6666  *		<process flags>		P_SUGID bit potentially modified
6667  *		<security token>	Potentially modified
6668  */
6669 __attribute__((noinline))
6670 static int
exec_handle_sugid(struct image_params * imgp)6671 exec_handle_sugid(struct image_params *imgp)
6672 {
6673 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
6674 	kauth_cred_t            cred = vfs_context_ucred(imgp->ip_vfs_context);
6675 	int                     i;
6676 	int                     leave_sugid_clear = 0;
6677 	int                     mac_reset_ipc = 0;
6678 	int                     error = 0;
6679 #if CONFIG_MACF
6680 	int                     mac_transition, disjoint_cred = 0;
6681 	int             label_update_return = 0;
6682 
6683 	/*
6684 	 * Determine whether a call to update the MAC label will result in the
6685 	 * credential changing.
6686 	 *
6687 	 * Note:	MAC policies which do not actually end up modifying
6688 	 *		the label subsequently are strongly encouraged to
6689 	 *		return 0 for this check, since a non-zero answer will
6690 	 *		slow down the exec fast path for normal binaries.
6691 	 */
6692 	mac_transition = mac_cred_check_label_update_execve(
6693 		imgp->ip_vfs_context,
6694 		imgp->ip_vp,
6695 		imgp->ip_arch_offset,
6696 		imgp->ip_scriptvp,
6697 		imgp->ip_scriptlabelp,
6698 		imgp->ip_execlabelp,
6699 		p,
6700 		&imgp->ip_px_smpx);
6701 #endif
6702 
6703 	OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
6704 
6705 	/*
6706 	 * Order of the following is important; group checks must go last,
6707 	 * as we use the success of the 'ismember' check combined with the
6708 	 * failure of the explicit match to indicate that we will be setting
6709 	 * the egid of the process even though the new process did not
6710 	 * require VSUID/VSGID bits in order for it to set the new group as
6711 	 * its egid.
6712 	 *
6713 	 * Note:	Technically, by this we are implying a call to
6714 	 *		setegid() in the new process, rather than implying
6715 	 *		it used its VSGID bit to set the effective group,
6716 	 *		even though there is no code in that process to make
6717 	 *		such a call.
6718 	 */
6719 	if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
6720 	    kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
6721 	    ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
6722 	    ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
6723 	    (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
6724 #if CONFIG_MACF
6725 /* label for MAC transition and neither VSUID nor VSGID */
6726 handle_mac_transition:
6727 #endif
6728 
6729 #if CONFIG_SETUID
6730 		/*
6731 		 * Replace the credential with a copy of itself if euid or
6732 		 * egid change.
6733 		 *
6734 		 * Note:	setuid binaries will automatically opt out of
6735 		 *		group resolver participation as a side effect
6736 		 *		of this operation.  This is an intentional
6737 		 *		part of the security model, which requires a
6738 		 *		participating credential be established by
6739 		 *		escalating privilege, setting up all other
6740 		 *		aspects of the credential including whether
6741 		 *		or not to participate in external group
6742 		 *		membership resolution, then dropping their
6743 		 *		effective privilege to that of the desired
6744 		 *		final credential state.
6745 		 *
6746 		 * Modifications to p_ucred must be guarded using the
6747 		 * proc's ucred lock. This prevents others from accessing
6748 		 * a garbage credential.
6749 		 */
6750 
6751 		if (imgp->ip_origvattr->va_mode & VSUID) {
6752 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6753 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6754 				return kauth_cred_model_setresuid(model,
6755 				KAUTH_UID_NONE,
6756 				imgp->ip_origvattr->va_uid,
6757 				imgp->ip_origvattr->va_uid,
6758 				KAUTH_UID_NONE);
6759 			});
6760 		}
6761 
6762 		if (imgp->ip_origvattr->va_mode & VSGID) {
6763 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6764 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6765 				return kauth_cred_model_setresgid(model,
6766 				KAUTH_GID_NONE,
6767 				imgp->ip_origvattr->va_gid,
6768 				imgp->ip_origvattr->va_gid);
6769 			});
6770 		}
6771 #endif /* CONFIG_SETUID */
6772 
6773 #if CONFIG_MACF
6774 		/*
6775 		 * If a policy has indicated that it will transition the label,
6776 		 * before making the call into the MAC policies, get a new
6777 		 * duplicate credential, so they can modify it without
6778 		 * modifying any others sharing it.
6779 		 */
6780 		if (mac_transition) {
6781 			/*
6782 			 * This hook may generate upcalls that require
6783 			 * importance donation from the kernel.
6784 			 * (23925818)
6785 			 */
6786 			thread_t thread = current_thread();
6787 			thread_enable_send_importance(thread, TRUE);
6788 			kauth_proc_label_update_execve(p,
6789 			    imgp->ip_vfs_context,
6790 			    imgp->ip_vp,
6791 			    imgp->ip_arch_offset,
6792 			    imgp->ip_scriptvp,
6793 			    imgp->ip_scriptlabelp,
6794 			    imgp->ip_execlabelp,
6795 			    &imgp->ip_csflags,
6796 			    &imgp->ip_px_smpx,
6797 			    &disjoint_cred,                     /* will be non zero if disjoint */
6798 			    &label_update_return);
6799 			thread_enable_send_importance(thread, FALSE);
6800 
6801 			if (disjoint_cred) {
6802 				/*
6803 				 * If updating the MAC label resulted in a
6804 				 * disjoint credential, flag that we need to
6805 				 * set the P_SUGID bit.  This protects
6806 				 * against debuggers being attached by an
6807 				 * insufficiently privileged process onto the
6808 				 * result of a transition to a more privileged
6809 				 * credential.
6810 				 */
6811 				leave_sugid_clear = 0;
6812 			}
6813 
6814 			imgp->ip_mac_return = label_update_return;
6815 		}
6816 
6817 		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);
6818 
6819 #endif  /* CONFIG_MACF */
6820 
6821 		/*
6822 		 * If 'leave_sugid_clear' is non-zero, then we passed the
6823 		 * VSUID and MACF checks, and successfully determined that
6824 		 * the previous cred was a member of the VSGID group, but
6825 		 * that it was not the default at the time of the execve,
6826 		 * and that the post-labelling credential was not disjoint.
6827 		 * So we don't set the P_SUGID or reset mach ports and fds
6828 		 * on the basis of simply running this code.
6829 		 */
6830 		if (mac_reset_ipc || !leave_sugid_clear) {
6831 			/*
6832 			 * Have mach reset the task and thread ports.
6833 			 * We don't want anyone who had the ports before
6834 			 * a setuid exec to be able to access/control the
6835 			 * task/thread after.
6836 			 */
6837 			ipc_task_reset((imgp->ip_new_thread != NULL) ?
6838 			    get_threadtask(imgp->ip_new_thread) : proc_task(p));
6839 			ipc_thread_reset((imgp->ip_new_thread != NULL) ?
6840 			    imgp->ip_new_thread : current_thread());
6841 		}
6842 
6843 		if (!leave_sugid_clear) {
6844 			/*
6845 			 * Flag the process as setuid.
6846 			 */
6847 			OSBitOrAtomic(P_SUGID, &p->p_flag);
6848 
6849 			/*
6850 			 * Radar 2261856; setuid security hole fix
6851 			 * XXX For setuid processes, attempt to ensure that
6852 			 * stdin, stdout, and stderr are already allocated.
6853 			 * We do not want userland to accidentally allocate
6854 			 * descriptors in this range which has implied meaning
6855 			 * to libc.
6856 			 */
6857 			for (i = 0; i < 3; i++) {
6858 				if (fp_get_noref_locked(p, i) != NULL) {
6859 					continue;
6860 				}
6861 
6862 				/*
6863 				 * Do the kernel equivalent of
6864 				 *
6865 				 *      if i == 0
6866 				 *              (void) open("/dev/null", O_RDONLY);
6867 				 *      else
6868 				 *              (void) open("/dev/null", O_WRONLY);
6869 				 */
6870 
6871 				struct fileproc *fp;
6872 				int indx;
6873 				int flag;
6874 				struct nameidata *ndp = NULL;
6875 
6876 				if (i == 0) {
6877 					flag = FREAD;
6878 				} else {
6879 					flag = FWRITE;
6880 				}
6881 
6882 				if ((error = falloc_exec(p, imgp->ip_vfs_context,
6883 				    &fp, &indx)) != 0) {
6884 					continue;
6885 				}
6886 
6887 				ndp = kalloc_type(struct nameidata,
6888 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
6889 
6890 				NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
6891 				    CAST_USER_ADDR_T("/dev/null"),
6892 				    imgp->ip_vfs_context);
6893 
6894 				if ((error = vn_open(ndp, flag, 0)) != 0) {
6895 					fp_free(p, indx, fp);
6896 					kfree_type(struct nameidata, ndp);
6897 					break;
6898 				}
6899 
6900 				struct fileglob *fg = fp->fp_glob;
6901 
6902 				fg->fg_flag = flag;
6903 				fg->fg_ops = &vnops;
6904 				fp_set_data(fp, ndp->ni_vp);
6905 
6906 				vnode_put(ndp->ni_vp);
6907 
6908 				proc_fdlock(p);
6909 				procfdtbl_releasefd(p, indx, NULL);
6910 				fp_drop(p, indx, fp, 1);
6911 				proc_fdunlock(p);
6912 
6913 				kfree_type(struct nameidata, ndp);
6914 			}
6915 		}
6916 	}
6917 #if CONFIG_MACF
6918 	else {
6919 		/*
6920 		 * We are here because we were told that the MAC label will
6921 		 * be transitioned, and the binary is not VSUID or VSGID; to
6922 		 * deal with this case, we could either duplicate a lot of
6923 		 * code, or we can indicate we want to default the P_SUGID
6924 		 * bit clear and jump back up.
6925 		 */
6926 		if (mac_transition) {
6927 			leave_sugid_clear = 1;
6928 			goto handle_mac_transition;
6929 		}
6930 	}
6931 
6932 #endif  /* CONFIG_MACF */
6933 
6934 	/* Update the process' identity version and set the security token */
6935 	proc_setpidversion(p, OSIncrementAtomic(&nextpidversion));
6936 	task_set_uniqueid(proc_task(p));
6937 
6938 	/*
6939 	 * Implement the semantic where the effective user and group become
6940 	 * the saved user and group in exec'ed programs.
6941 	 */
6942 	kauth_cred_proc_update(p, PROC_SETTOKEN_ALWAYS,
6943 	    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6944 		posix_cred_t pcred = posix_cred_get(model);
6945 
6946 		if (pcred->cr_svuid == pcred->cr_uid &&
6947 		pcred->cr_svgid == pcred->cr_gid) {
6948 		        return false;
6949 		}
6950 
6951 		pcred->cr_svuid = pcred->cr_uid;
6952 		pcred->cr_svgid = pcred->cr_gid;
6953 		return true;
6954 	});
6955 
6956 	return error;
6957 }
6958 
6959 
6960 /*
6961  * create_unix_stack
6962  *
6963  * Description:	Set the user stack address for the process to the provided
6964  *		address.  If a custom stack was not set as a result of the
6965  *		load process (i.e. as specified by the image file for the
6966  *		executable), then allocate the stack in the provided map and
6967  *		set up appropriate guard pages for enforcing administrative
6968  *		limits on stack growth, if they end up being needed.
6969  *
6970  * Parameters:	p			Process to set stack on
6971  *		load_result		Information from mach-o load commands
6972  *		map			Address map in which to allocate the new stack
6973  *
6974  * Returns:	KERN_SUCCESS		Stack successfully created
6975  *		!KERN_SUCCESS		Mach failure code
6976  */
6977 __attribute__((noinline))
6978 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)6979 create_unix_stack(vm_map_t map, load_result_t* load_result,
6980     proc_t p)
6981 {
6982 	mach_vm_size_t          size, prot_size;
6983 	mach_vm_offset_t        addr, prot_addr;
6984 	kern_return_t           kr;
6985 
6986 	mach_vm_address_t       user_stack = load_result->user_stack;
6987 
6988 	proc_lock(p);
6989 	p->user_stack = (uintptr_t)user_stack;
6990 	if (load_result->custom_stack) {
6991 		p->p_lflag |= P_LCUSTOM_STACK;
6992 	}
6993 	proc_unlock(p);
6994 	if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
6995 		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);
6996 	}
6997 
6998 	if (load_result->user_stack_alloc_size > 0) {
6999 		/*
7000 		 * Allocate enough space for the maximum stack size we
7001 		 * will ever authorize and an extra page to act as
7002 		 * a guard page for stack overflows. For default stacks,
7003 		 * vm_initial_limit_stack takes care of the extra guard page.
7004 		 * Otherwise we must allocate it ourselves.
7005 		 */
7006 		if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
7007 			return KERN_INVALID_ARGUMENT;
7008 		}
7009 		addr = vm_map_trunc_page(load_result->user_stack - size,
7010 		    vm_map_page_mask(map));
7011 		kr = mach_vm_allocate_kernel(map, &addr, size,
7012 		    VM_MAP_KERNEL_FLAGS_FIXED(.vm_tag = VM_MEMORY_STACK));
7013 		if (kr != KERN_SUCCESS) {
7014 			// Can't allocate at default location, try anywhere
7015 			addr = 0;
7016 			kr = mach_vm_allocate_kernel(map, &addr, size,
7017 			    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vm_tag = VM_MEMORY_STACK));
7018 			if (kr != KERN_SUCCESS) {
7019 				return kr;
7020 			}
7021 
7022 			user_stack = addr + size;
7023 			load_result->user_stack = (user_addr_t)user_stack;
7024 
7025 			proc_lock(p);
7026 			p->user_stack = (uintptr_t)user_stack;
7027 			proc_unlock(p);
7028 		}
7029 
7030 		load_result->user_stack_alloc = (user_addr_t)addr;
7031 
7032 		/*
7033 		 * And prevent access to what's above the current stack
7034 		 * size limit for this process.
7035 		 */
7036 		if (load_result->user_stack_size == 0) {
7037 			load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
7038 			prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
7039 		} else {
7040 			prot_size = PAGE_SIZE;
7041 		}
7042 
7043 		prot_addr = addr;
7044 		kr = mach_vm_protect(map,
7045 		    prot_addr,
7046 		    prot_size,
7047 		    FALSE,
7048 		    VM_PROT_NONE);
7049 		if (kr != KERN_SUCCESS) {
7050 			(void)mach_vm_deallocate(map, addr, size);
7051 			return kr;
7052 		}
7053 	}
7054 
7055 	return KERN_SUCCESS;
7056 }
7057 
7058 #include <sys/reboot.h>
7059 
7060 /*
7061  * load_init_program_at_path
7062  *
7063  * Description:	Load the "init" program; in most cases, this will be "launchd"
7064  *
7065  * Parameters:	p			Process to call execve() to create
7066  *					the "init" program
7067  *		scratch_addr		Page in p, scratch space
7068  *		path			NULL terminated path
7069  *
7070  * Returns:	KERN_SUCCESS		Success
7071  *		!KERN_SUCCESS           See execve/mac_execve for error codes
7072  *
7073  * Notes:	The process that is passed in is the first manufactured
7074  *		process on the system, and gets here via bsd_ast() firing
7075  *		for the first time.  This is done to ensure that bsd_init()
7076  *		has run to completion.
7077  *
7078  *		The address map of the first manufactured process matches the
7079  *		word width of the kernel. Once the self-exec completes, the
7080  *		initproc might be different.
7081  */
7082 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)7083 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
7084 {
7085 	int retval[2];
7086 	int error;
7087 	struct execve_args init_exec_args;
7088 	user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
7089 
7090 	/*
7091 	 * Validate inputs and pre-conditions
7092 	 */
7093 	assert(p);
7094 	assert(scratch_addr);
7095 	assert(path);
7096 
7097 	/*
7098 	 * Copy out program name.
7099 	 */
7100 	size_t path_length = strlen(path) + 1;
7101 	argv0 = scratch_addr;
7102 	error = copyout(path, argv0, path_length);
7103 	if (error) {
7104 		return error;
7105 	}
7106 
7107 	scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
7108 
7109 	/*
7110 	 * Put out first (and only) argument, similarly.
7111 	 * Assumes everything fits in a page as allocated above.
7112 	 */
7113 	if (boothowto & RB_SINGLE) {
7114 		const char *init_args = "-s";
7115 		size_t init_args_length = strlen(init_args) + 1;
7116 
7117 		argv1 = scratch_addr;
7118 		error = copyout(init_args, argv1, init_args_length);
7119 		if (error) {
7120 			return error;
7121 		}
7122 
7123 		scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
7124 	}
7125 
7126 	if (proc_is64bit(p)) {
7127 		user64_addr_t argv64bit[3] = {};
7128 
7129 		argv64bit[0] = argv0;
7130 		argv64bit[1] = argv1;
7131 		argv64bit[2] = USER_ADDR_NULL;
7132 
7133 		error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
7134 		if (error) {
7135 			return error;
7136 		}
7137 	} else {
7138 		user32_addr_t argv32bit[3] = {};
7139 
7140 		argv32bit[0] = (user32_addr_t)argv0;
7141 		argv32bit[1] = (user32_addr_t)argv1;
7142 		argv32bit[2] = USER_ADDR_NULL;
7143 
7144 		error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
7145 		if (error) {
7146 			return error;
7147 		}
7148 	}
7149 
7150 	/*
7151 	 * Set up argument block for fake call to execve.
7152 	 */
7153 	init_exec_args.fname = argv0;
7154 	init_exec_args.argp = scratch_addr;
7155 	init_exec_args.envp = USER_ADDR_NULL;
7156 
7157 	/*
7158 	 * So that init task is set with uid,gid 0 token
7159 	 *
7160 	 * The access to the cred is safe:
7161 	 * the proc isn't running yet, it's stable.
7162 	 */
7163 	set_security_token(p, proc_ucred_unsafe(p));
7164 
7165 	return execve(p, &init_exec_args, retval);
7166 }
7167 
7168 static const char * init_programs[] = {
7169 #if DEBUG
7170 	"/usr/appleinternal/sbin/launchd.debug",
7171 #endif
7172 #if DEVELOPMENT || DEBUG
7173 	"/usr/appleinternal/sbin/launchd.development",
7174 #endif
7175 	"/sbin/launchd",
7176 };
7177 
7178 /*
7179  * load_init_program
7180  *
7181  * Description:	Load the "init" program; in most cases, this will be "launchd"
7182  *
7183  * Parameters:	p			Process to call execve() to create
7184  *					the "init" program
7185  *
7186  * Returns:	(void)
7187  *
7188  * Notes:	The process that is passed in is the first manufactured
7189  *		process on the system, and gets here via bsd_ast() firing
7190  *		for the first time.  This is done to ensure that bsd_init()
7191  *		has run to completion.
7192  *
7193  *		In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
7194  *		may be used to select a specific launchd executable. As with
7195  *		the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
7196  *		will force /sbin/launchd to be selected.
7197  *
7198  *              Search order by build:
7199  *
7200  * DEBUG	DEVELOPMENT	RELEASE		PATH
7201  * ----------------------------------------------------------------------------------
7202  * 1		1		NA		/usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
7203  * 2		NA		NA		/usr/appleinternal/sbin/launchd.debug
7204  * 3		2		NA		/usr/appleinternal/sbin/launchd.development
7205  * 4		3		1		/sbin/launchd
7206  */
7207 void
load_init_program(proc_t p)7208 load_init_program(proc_t p)
7209 {
7210 	uint32_t i;
7211 	int error;
7212 	vm_map_t map = current_map();
7213 	mach_vm_offset_t scratch_addr = 0;
7214 	mach_vm_size_t map_page_size = vm_map_page_size(map);
7215 
7216 	(void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size,
7217 	    VM_MAP_KERNEL_FLAGS_ANYWHERE());
7218 #if CONFIG_MEMORYSTATUS
7219 	(void) memorystatus_init_at_boot_snapshot();
7220 #endif /* CONFIG_MEMORYSTATUS */
7221 
7222 #if DEBUG || DEVELOPMENT
7223 	/* Check for boot-arg suffix first */
7224 	char launchd_suffix[64];
7225 	if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
7226 		char launchd_path[128];
7227 		boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
7228 		    (strcmp(launchd_suffix, "release") == 0));
7229 
7230 		if (is_release_suffix) {
7231 			printf("load_init_program: attempting to load /sbin/launchd\n");
7232 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
7233 			if (!error) {
7234 				return;
7235 			}
7236 
7237 			panic("Process 1 exec of launchd.release failed, errno %d", error);
7238 		} else {
7239 			strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
7240 			strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
7241 
7242 			printf("load_init_program: attempting to load %s\n", launchd_path);
7243 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
7244 			if (!error) {
7245 				return;
7246 			} else if (error != ENOENT) {
7247 				printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
7248 			}
7249 		}
7250 	}
7251 #endif
7252 
7253 	error = ENOENT;
7254 	for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
7255 		printf("load_init_program: attempting to load %s\n", init_programs[i]);
7256 		error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
7257 		if (!error) {
7258 			return;
7259 		} else if (error != ENOENT) {
7260 			printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
7261 		}
7262 	}
7263 
7264 	panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
7265 }
7266 
7267 /*
7268  * load_return_to_errno
7269  *
7270  * Description:	Convert a load_return_t (Mach error) to an errno (BSD error)
7271  *
7272  * Parameters:	lrtn			Mach error number
7273  *
7274  * Returns:	(int)			BSD error number
7275  *		0			Success
7276  *		EBADARCH		Bad architecture
7277  *		EBADMACHO		Bad Mach object file
7278  *		ESHLIBVERS		Bad shared library version
7279  *		ENOMEM			Out of memory/resource shortage
7280  *		EACCES			Access denied
7281  *		ENOENT			Entry not found (usually "file does
7282  *					does not exist")
7283  *		EIO			An I/O error occurred
7284  *		EBADEXEC		The executable is corrupt/unknown
7285  */
7286 static int
load_return_to_errno(load_return_t lrtn)7287 load_return_to_errno(load_return_t lrtn)
7288 {
7289 	switch (lrtn) {
7290 	case LOAD_SUCCESS:
7291 		return 0;
7292 	case LOAD_BADARCH:
7293 		return EBADARCH;
7294 	case LOAD_BADMACHO:
7295 	case LOAD_BADMACHO_UPX:
7296 		return EBADMACHO;
7297 	case LOAD_SHLIB:
7298 		return ESHLIBVERS;
7299 	case LOAD_NOSPACE:
7300 	case LOAD_RESOURCE:
7301 		return ENOMEM;
7302 	case LOAD_PROTECT:
7303 		return EACCES;
7304 	case LOAD_ENOENT:
7305 		return ENOENT;
7306 	case LOAD_IOERROR:
7307 		return EIO;
7308 	case LOAD_DECRYPTFAIL:
7309 		return EAUTH;
7310 	case LOAD_FAILURE:
7311 	default:
7312 		return EBADEXEC;
7313 	}
7314 }
7315 
7316 #include <mach/mach_types.h>
7317 #include <mach/vm_prot.h>
7318 #include <mach/semaphore.h>
7319 #include <mach/sync_policy.h>
7320 #include <kern/clock.h>
7321 #include <mach/kern_return.h>
7322 
7323 /*
7324  * execargs_alloc
7325  *
7326  * Description:	Allocate the block of memory used by the execve arguments.
7327  *		At the same time, we allocate a page so that we can read in
7328  *		the first page of the image.
7329  *
7330  * Parameters:	struct image_params *	the image parameter block
7331  *
7332  * Returns:	0			Success
7333  *		EINVAL			Invalid argument
7334  *		EACCES			Permission denied
7335  *		EINTR			Interrupted function
7336  *		ENOMEM			Not enough space
7337  *
7338  * Notes:	This is a temporary allocation into the kernel address space
7339  *		to enable us to copy arguments in from user space.  This is
7340  *		necessitated by not mapping the process calling execve() into
7341  *		the kernel address space during the execve() system call.
7342  *
7343  *		We assemble the argument and environment, etc., into this
7344  *		region before copying it as a single block into the child
7345  *		process address space (at the top or bottom of the stack,
7346  *		depending on which way the stack grows; see the function
7347  *		exec_copyout_strings() for details).
7348  *
7349  *		This ends up with a second (possibly unnecessary) copy compared
7350  *		with assembing the data directly into the child address space,
7351  *		instead, but since we cannot be guaranteed that the parent has
7352  *		not modified its environment, we can't really know that it's
7353  *		really a block there as well.
7354  */
7355 
7356 
7357 static int execargs_waiters = 0;
7358 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
7359 
7360 static void
execargs_lock_lock(void)7361 execargs_lock_lock(void)
7362 {
7363 	lck_mtx_lock_spin(&execargs_cache_lock);
7364 }
7365 
7366 static void
execargs_lock_unlock(void)7367 execargs_lock_unlock(void)
7368 {
7369 	lck_mtx_unlock(&execargs_cache_lock);
7370 }
7371 
7372 static wait_result_t
execargs_lock_sleep(void)7373 execargs_lock_sleep(void)
7374 {
7375 	return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
7376 }
7377 
7378 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)7379 execargs_purgeable_allocate(char **execarg_address)
7380 {
7381 	mach_vm_offset_t addr = 0;
7382 	kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
7383 	    BSD_PAGEABLE_SIZE_PER_EXEC,
7384 	    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vmf_purgeable = true));
7385 	*execarg_address = (char *)addr;
7386 	assert(kr == KERN_SUCCESS);
7387 	return kr;
7388 }
7389 
7390 static kern_return_t
execargs_purgeable_reference(void * execarg_address)7391 execargs_purgeable_reference(void *execarg_address)
7392 {
7393 	int state = VM_PURGABLE_NONVOLATILE;
7394 	kern_return_t kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7395 
7396 	assert(kr == KERN_SUCCESS);
7397 	return kr;
7398 }
7399 
7400 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)7401 execargs_purgeable_volatilize(void *execarg_address)
7402 {
7403 	int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
7404 	kern_return_t kr;
7405 	kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7406 
7407 	assert(kr == KERN_SUCCESS);
7408 
7409 	return kr;
7410 }
7411 
7412 static void
execargs_wakeup_waiters(void)7413 execargs_wakeup_waiters(void)
7414 {
7415 	thread_wakeup(&execargs_free_count);
7416 }
7417 
7418 static int
execargs_alloc(struct image_params * imgp)7419 execargs_alloc(struct image_params *imgp)
7420 {
7421 	kern_return_t kret;
7422 	wait_result_t res;
7423 	int i, cache_index = -1;
7424 
7425 	execargs_lock_lock();
7426 
7427 	while (execargs_free_count == 0) {
7428 		execargs_waiters++;
7429 		res = execargs_lock_sleep();
7430 		execargs_waiters--;
7431 		if (res != THREAD_AWAKENED) {
7432 			execargs_lock_unlock();
7433 			return EINTR;
7434 		}
7435 	}
7436 
7437 	execargs_free_count--;
7438 
7439 	for (i = 0; i < execargs_cache_size; i++) {
7440 		vm_offset_t element = execargs_cache[i];
7441 		if (element) {
7442 			cache_index = i;
7443 			imgp->ip_strings = (char *)(execargs_cache[i]);
7444 			execargs_cache[i] = 0;
7445 			break;
7446 		}
7447 	}
7448 
7449 	assert(execargs_free_count >= 0);
7450 
7451 	execargs_lock_unlock();
7452 
7453 	if (cache_index == -1) {
7454 		kret = execargs_purgeable_allocate(&imgp->ip_strings);
7455 	} else {
7456 		kret = execargs_purgeable_reference(imgp->ip_strings);
7457 	}
7458 
7459 	assert(kret == KERN_SUCCESS);
7460 	if (kret != KERN_SUCCESS) {
7461 		return ENOMEM;
7462 	}
7463 
7464 	/* last page used to read in file headers */
7465 	imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
7466 	imgp->ip_strendp = imgp->ip_strings;
7467 	imgp->ip_argspace = NCARGS;
7468 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
7469 
7470 	return 0;
7471 }
7472 
7473 /*
7474  * execargs_free
7475  *
7476  * Description:	Free the block of memory used by the execve arguments and the
7477  *		first page of the executable by a previous call to the function
7478  *		execargs_alloc().
7479  *
7480  * Parameters:	struct image_params *	the image parameter block
7481  *
7482  * Returns:	0			Success
7483  *		EINVAL			Invalid argument
7484  *		EINTR			Oeration interrupted
7485  */
7486 static int
execargs_free(struct image_params * imgp)7487 execargs_free(struct image_params *imgp)
7488 {
7489 	kern_return_t kret;
7490 	int i;
7491 	boolean_t needs_wakeup = FALSE;
7492 
7493 	kret = execargs_purgeable_volatilize(imgp->ip_strings);
7494 
7495 	execargs_lock_lock();
7496 	execargs_free_count++;
7497 
7498 	for (i = 0; i < execargs_cache_size; i++) {
7499 		vm_offset_t element = execargs_cache[i];
7500 		if (element == 0) {
7501 			execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
7502 			imgp->ip_strings = NULL;
7503 			break;
7504 		}
7505 	}
7506 
7507 	assert(imgp->ip_strings == NULL);
7508 
7509 	if (execargs_waiters > 0) {
7510 		needs_wakeup = TRUE;
7511 	}
7512 
7513 	execargs_lock_unlock();
7514 
7515 	if (needs_wakeup == TRUE) {
7516 		execargs_wakeup_waiters();
7517 	}
7518 
7519 	return kret == KERN_SUCCESS ? 0 : EINVAL;
7520 }
7521 
7522 void
uthread_set_exec_data(struct uthread * uth,struct image_params * imgp)7523 uthread_set_exec_data(struct uthread *uth, struct image_params *imgp)
7524 {
7525 	uth->uu_save.uus_exec_data.imgp = imgp;
7526 }
7527 
7528 size_t
thread_get_current_exec_path(char * path,size_t size)7529 thread_get_current_exec_path(char *path, size_t size)
7530 {
7531 	struct uthread *uth = current_uthread();
7532 	struct image_params *imgp = uth->uu_save.uus_exec_data.imgp;
7533 	size_t string_size = 0;
7534 	char *exec_path;
7535 
7536 	if (path == NULL || imgp == NULL || imgp->ip_strings == NULL) {
7537 		return 0;
7538 	}
7539 
7540 	exec_path = imgp->ip_strings + strlen(EXECUTABLE_KEY);
7541 	string_size = imgp->ip_strendp - exec_path;
7542 	string_size = MIN(MAXPATHLEN, string_size);
7543 	string_size = MIN(size, string_size);
7544 
7545 	string_size = strlcpy(path, exec_path, string_size);
7546 	return string_size;
7547 }
7548 static void
exec_resettextvp(proc_t p,struct image_params * imgp)7549 exec_resettextvp(proc_t p, struct image_params *imgp)
7550 {
7551 	vnode_t vp;
7552 	off_t offset;
7553 	vnode_t tvp  = p->p_textvp;
7554 	int ret;
7555 
7556 	vp = imgp->ip_vp;
7557 	offset = imgp->ip_arch_offset;
7558 
7559 	if (vp == NULLVP) {
7560 		panic("exec_resettextvp: expected valid vp");
7561 	}
7562 
7563 	ret = vnode_ref(vp);
7564 	proc_lock(p);
7565 	if (ret == 0) {
7566 		p->p_textvp = vp;
7567 		p->p_textoff = offset;
7568 	} else {
7569 		p->p_textvp = NULLVP;   /* this is paranoia */
7570 		p->p_textoff = 0;
7571 	}
7572 	proc_unlock(p);
7573 
7574 	if (tvp != NULLVP) {
7575 		if (vnode_getwithref(tvp) == 0) {
7576 			vnode_rele(tvp);
7577 			vnode_put(tvp);
7578 		}
7579 	}
7580 }
7581 
7582 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
7583 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
7584 
7585 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)7586 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
7587 {
7588 	static char const nibble[] = "0123456789abcdef";
7589 
7590 	/* Apparently still the safest way to get a hex representation
7591 	 * of binary data.
7592 	 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
7593 	 * <rdar://problem/33328859> confusion around %*D/%nD in printf
7594 	 */
7595 	for (int i = 0; i < CS_CDHASH_LEN; ++i) {
7596 		str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
7597 		str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
7598 	}
7599 	str[CS_CDHASH_STRING_SIZE - 1] = 0;
7600 }
7601 
7602 /*
7603  * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
7604  *
7605  * Description: Waits for the userspace daemon to respond to the request
7606  *              we made. Function declared non inline to be visible in
7607  *		stackshots and spindumps as well as debugging.
7608  */
7609 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)7610 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
7611 {
7612 	return find_code_signature(task_access_port, new_pid);
7613 }
7614 
7615 /*
7616  * Update signature dependent process state, called by
7617  * process_signature.
7618  */
7619 static int
proc_process_signature(proc_t p,os_reason_t * signature_failure_reason)7620 proc_process_signature(proc_t p, os_reason_t *signature_failure_reason)
7621 {
7622 	int error = 0;
7623 	char const *error_msg = NULL;
7624 
7625 	kern_return_t kr = machine_task_process_signature(proc_get_task_raw(p), proc_platform(p), proc_sdk(p), &error_msg);
7626 
7627 	if (kr != KERN_SUCCESS) {
7628 		error = EINVAL;
7629 
7630 		if (error_msg != NULL) {
7631 			uint32_t error_msg_len = (uint32_t)strlen(error_msg) + 1;
7632 			mach_vm_address_t data_addr = 0;
7633 			int reason_error = 0;
7634 			int kcdata_error = 0;
7635 
7636 			os_reason_t reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7637 			reason->osr_flags = OS_REASON_FLAG_GENERATE_CRASH_REPORT | OS_REASON_FLAG_CONSISTENT_FAILURE;
7638 
7639 			if ((reason_error = os_reason_alloc_buffer_noblock(reason,
7640 			    kcdata_estimate_required_buffer_size(1, error_msg_len))) == 0 &&
7641 			    (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
7642 			    EXIT_REASON_USER_DESC, error_msg_len,
7643 			    &data_addr)) == KERN_SUCCESS) {
7644 				kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
7645 				    error_msg, error_msg_len);
7646 
7647 				if (mc_error != KERN_SUCCESS) {
7648 					printf("process_signature: failed to copy reason string (kcdata_memcpy error: %d)\n",
7649 					    mc_error);
7650 				}
7651 			} else {
7652 				printf("failed to allocate space for reason string (os_reason_alloc_buffer error: %d, kcdata error: %d, length: %u)\n",
7653 				    reason_error, kcdata_error, error_msg_len);
7654 			}
7655 
7656 			assert(*signature_failure_reason == NULL); // shouldn't have gotten so far
7657 			*signature_failure_reason = reason;
7658 		}
7659 	}
7660 	return error;
7661 }
7662 
7663 static int
process_signature(proc_t p,struct image_params * imgp)7664 process_signature(proc_t p, struct image_params *imgp)
7665 {
7666 	mach_port_t port = IPC_PORT_NULL;
7667 	kern_return_t kr = KERN_FAILURE;
7668 	int error = EACCES;
7669 	boolean_t unexpected_failure = FALSE;
7670 	struct cs_blob *csb;
7671 	boolean_t require_success = FALSE;
7672 	int spawn = (imgp->ip_flags & IMGPF_SPAWN);
7673 	const int vfexec = 0;
7674 	os_reason_t signature_failure_reason = OS_REASON_NULL;
7675 
7676 	/*
7677 	 * Override inherited code signing flags with the
7678 	 * ones for the process that is being successfully
7679 	 * loaded
7680 	 */
7681 	proc_lock(p);
7682 	proc_csflags_update(p, imgp->ip_csflags);
7683 	proc_unlock(p);
7684 
7685 	/* Set the switch_protect flag on the map */
7686 	if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
7687 		vm_map_switch_protect(get_task_map(proc_task(p)), TRUE);
7688 	}
7689 	/* set the cs_enforced flags in the map */
7690 	if (proc_getcsflags(p) & CS_ENFORCEMENT) {
7691 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), TRUE);
7692 	} else {
7693 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), FALSE);
7694 	}
7695 
7696 	/*
7697 	 * image activation may be failed due to policy
7698 	 * which is unexpected but security framework does not
7699 	 * approve of exec, kill and return immediately.
7700 	 */
7701 	if (imgp->ip_mac_return != 0) {
7702 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7703 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
7704 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7705 		error = imgp->ip_mac_return;
7706 		unexpected_failure = TRUE;
7707 		goto done;
7708 	}
7709 
7710 	if (imgp->ip_cs_error != OS_REASON_NULL) {
7711 		signature_failure_reason = imgp->ip_cs_error;
7712 		imgp->ip_cs_error = OS_REASON_NULL;
7713 		error = EACCES;
7714 		goto done;
7715 	}
7716 
7717 	/* call the launch constraints hook */
7718 	os_reason_t launch_constraint_reason;
7719 	if ((error = mac_proc_check_launch_constraints(p, imgp, &launch_constraint_reason)) != 0) {
7720 		signature_failure_reason = launch_constraint_reason;
7721 		goto done;
7722 	}
7723 
7724 #if XNU_TARGET_OS_OSX
7725 	/* Check for platform passed in spawn attr if iOS binary is being spawned */
7726 	if (proc_platform(p) == PLATFORM_IOS) {
7727 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
7728 		if (psa == NULL || psa->psa_platform == 0) {
7729 			boolean_t no_sandbox_entitled = FALSE;
7730 #if DEBUG || DEVELOPMENT
7731 			/*
7732 			 * Allow iOS binaries to spawn on internal systems
7733 			 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
7734 			 * boot-arg set to true
7735 			 */
7736 			if (unentitled_ios_sim_launch) {
7737 				no_sandbox_entitled = TRUE;
7738 			} else {
7739 				no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
7740 				    (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
7741 			}
7742 #endif /* DEBUG || DEVELOPMENT */
7743 			if (!no_sandbox_entitled) {
7744 				signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7745 				    EXEC_EXIT_REASON_WRONG_PLATFORM);
7746 				error = EACCES;
7747 				goto done;
7748 			}
7749 			printf("Allowing spawn of iOS binary %s since it has "
7750 			    "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
7751 			    "boot-arg set to true\n", p->p_name);
7752 		} else if (psa->psa_platform != PLATFORM_IOS) {
7753 			/* Simulator binary spawned with wrong platform */
7754 			signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7755 			    EXEC_EXIT_REASON_WRONG_PLATFORM);
7756 			error = EACCES;
7757 			goto done;
7758 		} else {
7759 			printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
7760 			    p->p_name);
7761 		}
7762 	}
7763 #endif /* XNU_TARGET_OS_OSX */
7764 
7765 	/* If the code signature came through the image activation path, we skip the
7766 	 * taskgated / externally attached path. */
7767 	if (imgp->ip_csflags & CS_SIGNED) {
7768 		error = 0;
7769 		goto done;
7770 	}
7771 
7772 	/* The rest of the code is for signatures that either already have been externally
7773 	 * attached (likely, but not necessarily by a previous run through the taskgated
7774 	 * path), or that will now be attached by taskgated. */
7775 
7776 	kr = task_get_task_access_port(proc_task(p), &port);
7777 	if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
7778 		error = 0;
7779 		if (require_success) {
7780 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7781 			    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
7782 			signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
7783 			error = EACCES;
7784 		}
7785 		goto done;
7786 	}
7787 
7788 	/*
7789 	 * taskgated returns KERN_SUCCESS if it has completed its work
7790 	 * and the exec should continue, KERN_FAILURE if the exec should
7791 	 * fail, or it may error out with different error code in an
7792 	 * event of mig failure (e.g. process was signalled during the
7793 	 * rpc call, taskgated died, mig server died etc.).
7794 	 */
7795 
7796 	kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
7797 	switch (kr) {
7798 	case KERN_SUCCESS:
7799 		error = 0;
7800 		break;
7801 	case KERN_FAILURE:
7802 		error = EACCES;
7803 
7804 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7805 		    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
7806 		signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
7807 		goto done;
7808 	default:
7809 		error = EACCES;
7810 
7811 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7812 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
7813 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
7814 		unexpected_failure = TRUE;
7815 		goto done;
7816 	}
7817 
7818 	/* Only do this if exec_resettextvp() did not fail */
7819 	if (p->p_textvp != NULLVP) {
7820 		csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
7821 
7822 		if (csb != NULL) {
7823 			/* As the enforcement we can do here is very limited, we only allow things that
7824 			 * are the only reason why this code path still exists:
7825 			 * Adhoc signed non-platform binaries without special cs_flags and without any
7826 			 * entitlements (unrestricted ones still pass AMFI). */
7827 			if (
7828 				/* Revalidate the blob if necessary through bumped generation count. */
7829 				(ubc_cs_generation_check(p->p_textvp) == 0 ||
7830 				ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
7831 				/* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
7832 				(csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
7833 				/* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
7834 				csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
7835 				CSSLOT_SIGNATURESLOT,
7836 				CSMAGIC_BLOBWRAPPER) == NULL &&
7837 				/* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
7838 				csb->csb_platform_binary == 0 &&
7839 				/* No entitlements, not even unrestricted ones. */
7840 				csb->csb_entitlements_blob == NULL &&
7841 				csb->csb_der_entitlements_blob == NULL) {
7842 				proc_lock(p);
7843 				proc_csflags_set(p, CS_SIGNED | CS_VALID);
7844 				proc_unlock(p);
7845 			} else {
7846 				uint8_t cdhash[CS_CDHASH_LEN];
7847 				char cdhash_string[CS_CDHASH_STRING_SIZE];
7848 				proc_getcdhash(p, cdhash);
7849 				cdhash_to_string(cdhash_string, cdhash);
7850 				printf("ignoring detached code signature on '%s' with cdhash '%s' "
7851 				    "because it is invalid, or not a simple adhoc signature.\n",
7852 				    p->p_name, cdhash_string);
7853 			}
7854 		}
7855 	}
7856 
7857 done:
7858 	if (0 == error) {
7859 		/*
7860 		 * Update the new process's signature-dependent process state.
7861 		 * state.
7862 		 */
7863 
7864 		error = proc_process_signature(p, &signature_failure_reason);
7865 	}
7866 
7867 	if (0 == error) {
7868 		/*
7869 		 * Update the new main thread's signature-dependent thread
7870 		 * state. This was also called when the thread was created,
7871 		 * but for the main thread the signature was not yet attached
7872 		 * at that time.
7873 		 */
7874 		kr = thread_process_signature(imgp->ip_new_thread, proc_get_task_raw(p));
7875 
7876 		if (kr != KERN_SUCCESS) {
7877 			error = EINVAL;
7878 			signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MACHINE_THREAD);
7879 		}
7880 	}
7881 
7882 	if (0 == error) {
7883 		/* The process's code signature related properties are
7884 		 * fully set up, so this is an opportune moment to log
7885 		 * platform binary execution, if desired. */
7886 		if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
7887 			uint8_t cdhash[CS_CDHASH_LEN];
7888 			char cdhash_string[CS_CDHASH_STRING_SIZE];
7889 			proc_getcdhash(p, cdhash);
7890 			cdhash_to_string(cdhash_string, cdhash);
7891 
7892 			os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
7893 			    "'%s' with cdhash %s\n", p->p_name, cdhash_string);
7894 		}
7895 	} else {
7896 		if (!unexpected_failure) {
7897 			proc_csflags_set(p, CS_KILLED);
7898 		}
7899 		/* make very sure execution fails */
7900 		if (vfexec || spawn) {
7901 			assert(signature_failure_reason != OS_REASON_NULL);
7902 			psignal_vfork_with_reason(p, proc_task(p), imgp->ip_new_thread,
7903 			    SIGKILL, signature_failure_reason);
7904 			signature_failure_reason = OS_REASON_NULL;
7905 			error = 0;
7906 		} else {
7907 			assert(signature_failure_reason != OS_REASON_NULL);
7908 			psignal_with_reason(p, SIGKILL, signature_failure_reason);
7909 			signature_failure_reason = OS_REASON_NULL;
7910 		}
7911 	}
7912 
7913 	if (port != IPC_PORT_NULL) {
7914 		ipc_port_release_send(port);
7915 	}
7916 
7917 	/* If we hit this, we likely would have leaked an exit reason */
7918 	assert(signature_failure_reason == OS_REASON_NULL);
7919 	return error;
7920 }
7921 
7922 /*
7923  * Typically as soon as we start executing this process, the
7924  * first instruction will trigger a VM fault to bring the text
7925  * pages (as executable) into the address space, followed soon
7926  * thereafter by dyld data structures (for dynamic executable).
7927  * To optimize this, as well as improve support for hardware
7928  * debuggers that can only access resident pages present
7929  * in the process' page tables, we prefault some pages if
7930  * possible. Errors are non-fatal.
7931  */
7932 #ifndef PREVENT_CALLER_STACK_USE
7933 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
7934 #endif
7935 
7936 /*
7937  * Prefaulting dyld data does not work (rdar://76621401)
7938  */
7939 #define FIXED_76621401 0
7940 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(__unused proc_t p,__unused struct image_params * imgp,__unused load_result_t * load_result)7941 exec_prefault_data(
7942 	__unused proc_t p,
7943 	__unused struct image_params *imgp,
7944 	__unused load_result_t *load_result)
7945 {
7946 #if FIXED_76621401
7947 	int ret;
7948 	size_t expected_all_image_infos_size;
7949 #endif /* FIXED_76621401 */
7950 	kern_return_t kr;
7951 
7952 	/*
7953 	 * Prefault executable or dyld entry point.
7954 	 */
7955 	if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7956 		DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
7957 	}
7958 	kr = vm_fault(current_map(),
7959 	    vm_map_trunc_page(load_result->entry_point,
7960 	    vm_map_page_mask(current_map())),
7961 	    VM_PROT_READ | VM_PROT_EXECUTE,
7962 	    FALSE, VM_KERN_MEMORY_NONE,
7963 	    THREAD_UNINT, NULL, 0);
7964 	if (kr != KERN_SUCCESS) {
7965 		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);
7966 	}
7967 
7968 #if FIXED_76621401
7969 	if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7970 		expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
7971 	} else {
7972 		expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
7973 	}
7974 
7975 	/* Decode dyld anchor structure from <mach-o/dyld_images.h> */
7976 	if (load_result->dynlinker &&
7977 	    load_result->all_image_info_addr &&
7978 	    load_result->all_image_info_size >= expected_all_image_infos_size) {
7979 		union {
7980 			struct user64_dyld_all_image_infos      infos64;
7981 			struct user32_dyld_all_image_infos      infos32;
7982 		} all_image_infos;
7983 
7984 		/*
7985 		 * Pre-fault to avoid copyin() going through the trap handler
7986 		 * and recovery path.
7987 		 */
7988 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7989 			DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
7990 		}
7991 		kr = vm_fault(current_map(),
7992 		    vm_map_trunc_page(load_result->all_image_info_addr,
7993 		    vm_map_page_mask(current_map())),
7994 		    VM_PROT_READ | VM_PROT_WRITE,
7995 		    FALSE, VM_KERN_MEMORY_NONE,
7996 		    THREAD_UNINT, NULL, 0);
7997 		if (kr != KERN_SUCCESS) {
7998 //			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);
7999 		}
8000 		if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
8001 			/* all_image_infos straddles a page */
8002 			kr = vm_fault(current_map(),
8003 			    vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
8004 			    vm_map_page_mask(current_map())),
8005 			    VM_PROT_READ | VM_PROT_WRITE,
8006 			    FALSE, VM_KERN_MEMORY_NONE,
8007 			    THREAD_UNINT, NULL, 0);
8008 			if (kr != KERN_SUCCESS) {
8009 //				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);
8010 			}
8011 		}
8012 
8013 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8014 			DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
8015 		}
8016 		ret = copyin((user_addr_t)load_result->all_image_info_addr,
8017 		    &all_image_infos,
8018 		    expected_all_image_infos_size);
8019 		if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
8020 			user_addr_t notification_address;
8021 			user_addr_t dyld_image_address;
8022 			user_addr_t dyld_version_address;
8023 			user_addr_t dyld_all_image_infos_address;
8024 			user_addr_t dyld_slide_amount;
8025 
8026 			if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
8027 				notification_address = (user_addr_t)all_image_infos.infos64.notification;
8028 				dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
8029 				dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
8030 				dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
8031 			} else {
8032 				notification_address = all_image_infos.infos32.notification;
8033 				dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
8034 				dyld_version_address = all_image_infos.infos32.dyldVersion;
8035 				dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
8036 			}
8037 
8038 			/*
8039 			 * dyld statically sets up the all_image_infos in its Mach-O
8040 			 * binary at static link time, with pointers relative to its default
8041 			 * load address. Since ASLR might slide dyld before its first
8042 			 * instruction is executed, "dyld_slide_amount" tells us how far
8043 			 * dyld was loaded compared to its default expected load address.
8044 			 * All other pointers into dyld's image should be adjusted by this
8045 			 * amount. At some point later, dyld will fix up pointers to take
8046 			 * into account the slide, at which point the all_image_infos_address
8047 			 * field in the structure will match the runtime load address, and
8048 			 * "dyld_slide_amount" will be 0, if we were to consult it again.
8049 			 */
8050 
8051 			dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
8052 
8053 #if 0
8054 			kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
8055 			    (uint64_t)load_result->all_image_info_addr,
8056 			    all_image_infos.infos32.version,
8057 			    (uint64_t)notification_address,
8058 			    (uint64_t)dyld_image_address,
8059 			    (uint64_t)dyld_version_address,
8060 			    (uint64_t)dyld_all_image_infos_address);
8061 #endif
8062 
8063 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8064 				DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
8065 			}
8066 			kr = vm_fault(current_map(),
8067 			    vm_map_trunc_page(notification_address + dyld_slide_amount,
8068 			    vm_map_page_mask(current_map())),
8069 			    VM_PROT_READ | VM_PROT_EXECUTE,
8070 			    FALSE, VM_KERN_MEMORY_NONE,
8071 			    THREAD_UNINT, NULL, 0);
8072 			if (kr != KERN_SUCCESS) {
8073 //				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);
8074 			}
8075 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8076 				DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
8077 			}
8078 			kr = vm_fault(current_map(),
8079 			    vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
8080 			    vm_map_page_mask(current_map())),
8081 			    VM_PROT_READ | VM_PROT_EXECUTE,
8082 			    FALSE, VM_KERN_MEMORY_NONE,
8083 			    THREAD_UNINT, NULL, 0);
8084 			if (kr != KERN_SUCCESS) {
8085 //				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);
8086 			}
8087 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8088 				DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
8089 			}
8090 			kr = vm_fault(current_map(),
8091 			    vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
8092 			    vm_map_page_mask(current_map())),
8093 			    VM_PROT_READ,
8094 			    FALSE, VM_KERN_MEMORY_NONE,
8095 			    THREAD_UNINT, NULL, 0);
8096 			if (kr != KERN_SUCCESS) {
8097 //				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);
8098 			}
8099 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8100 				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);
8101 			}
8102 			kr = vm_fault(current_map(),
8103 			    vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
8104 			    vm_map_page_mask(current_map())),
8105 			    VM_PROT_READ | VM_PROT_WRITE,
8106 			    FALSE, VM_KERN_MEMORY_NONE,
8107 			    THREAD_UNINT, NULL, 0);
8108 			if (kr != KERN_SUCCESS) {
8109 //				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);
8110 			}
8111 		}
8112 	}
8113 #endif /* FIXED_76621401 */
8114 }
8115 
8116 static int
8117 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
8118 {
8119 #pragma unused(oidp, arg2, req)
8120 	int changed;
8121 	errno_t error;
8122 	uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
8123 
8124 	error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
8125 	if (error) {
8126 		return error;
8127 	}
8128 
8129 	if (changed) {
8130 		os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
8131 	}
8132 
8133 	return 0;
8134 }
8135 
8136 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
8137 
8138 SYSCTL_NODE(_kern, OID_AUTO, sec_transition,
8139     CTLFLAG_RD | CTLFLAG_LOCKED, 0, "sec_transition");
8140 
8141 
8142 SYSCTL_INT(_kern_sec_transition, OID_AUTO, available,
8143     CTLFLAG_RD | CTLFLAG_LOCKED, (int *)NULL, 0, "");
8144 
8145