xref: /xnu-10002.81.5/bsd/kern/kern_exec.c (revision 5e3eaea39dcf651e66cb99ba7d70e32cc4a99587)
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.h>
163 #include <vm/vm_kern.h>
164 #include <vm/vm_protos.h>
165 #include <vm/vm_kern.h>
166 #include <vm/vm_fault.h>
167 #include <vm/vm_pageout.h>
168 #include <vm/pmap.h>
169 #include <vm/vm_reclaim_internal.h>
170 
171 #include <kdp/kdp_dyld.h>
172 
173 #include <machine/machine_routines.h>
174 #include <machine/pal_routines.h>
175 
176 #include <pexpert/pexpert.h>
177 
178 #if CONFIG_MEMORYSTATUS
179 #include <sys/kern_memorystatus.h>
180 #endif
181 
182 #include <IOKit/IOBSD.h>
183 
184 #include "kern_exec_internal.h"
185 
186 extern boolean_t vm_darkwake_mode;
187 
188 /* enable crash reports on various exec failures */
189 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
190 
191 #if XNU_TARGET_OS_OSX
192 #if __has_feature(ptrauth_calls)
193 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
194 #endif /* __has_feature(ptrauth_calls) */
195 
196 #if DEBUG || DEVELOPMENT
197 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
198 #endif /* DEBUG || DEVELOPMENT */
199 #endif /* XNU_TARGET_OS_OSX */
200 
201 #if CONFIG_DTRACE
202 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
203 extern void dtrace_proc_exec(proc_t);
204 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
205 
206 /*
207  * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
208  * we will store its value before actually calling it.
209  */
210 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
211 
212 #include <sys/dtrace_ptss.h>
213 #endif
214 
215 #if __has_feature(ptrauth_calls)
216 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
217     "vm_shared_region_per_team_id", 1);
218 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
219     "vm_shared_region_by_entitlement", 1);
220 
221 /* Upon userland request, reslide the shared cache. */
222 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
223     "vm_shared_region_reslide_aslr",
224 #if CONFIG_RESLIDE_SHARED_CACHE
225     1
226 #else
227     0
228 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
229     );
230 
231 /*
232  * Flag to control what processes should get shared cache randomize resliding
233  * after a fault in the shared cache region:
234  *
235  * 0 - all processes get a new randomized slide
236  * 1 - only platform processes get a new randomized slide
237  */
238 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
239     "vm_shared_region_reslide_restrict", 1);
240 
241 #if DEVELOPMENT || DEBUG
242 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
243     CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
244 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
245     CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
246 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
247     CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
248 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
249     CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
250 #endif
251 #endif /* __has_feature(ptrauth_calls) */
252 
253 #if DEVELOPMENT || DEBUG
254 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", true);
255 #else
256 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", false);
257 #endif
258 extern kern_return_t kern_register_userspace_coredump(task_t task, const char * name);
259 #define USERSPACE_COREDUMP_PANIC_ENTITLEMENT "com.apple.private.enable-coredump-on-panic"
260 #define USERSPACE_COREDUMP_PANIC_SEED_ENTITLEMENT \
261 	"com.apple.private.enable-coredump-on-panic-seed-privacy-approved"
262 
263 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
264 extern void task_set_did_exec_flag(task_t task);
265 extern void task_clear_exec_copy_flag(task_t task);
266 proc_t proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task,
267     task_t new_task, thread_t new_thread, void **inherit);
268 boolean_t task_is_active(task_t);
269 boolean_t thread_is_active(thread_t thread);
270 void thread_copy_resource_info(thread_t dst_thread, thread_t src_thread);
271 void *ipc_importance_exec_switch_task(task_t old_task, task_t new_task);
272 extern void ipc_importance_release(void *elem);
273 extern boolean_t task_has_watchports(task_t task);
274 extern void task_set_no_smt(task_t task);
275 #if defined(HAS_APPLE_PAC)
276 char *task_get_vm_shared_region_id_and_jop_pid(task_t task, uint64_t *jop_pid);
277 #endif
278 task_t convert_port_to_task(ipc_port_t port);
279 
280 
281 /*
282  * Mach things for which prototypes are unavailable from Mach headers
283  */
284 #define IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND 0x1
285 void            ipc_task_enable(
286 	task_t          task);
287 void            ipc_task_reset(
288 	task_t          task);
289 void            ipc_thread_reset(
290 	thread_t        thread);
291 kern_return_t ipc_object_copyin(
292 	ipc_space_t             space,
293 	mach_port_name_t        name,
294 	mach_msg_type_name_t    msgt_name,
295 	ipc_object_t            *objectp,
296 	mach_port_context_t     context,
297 	mach_msg_guard_flags_t  *guard_flags,
298 	uint32_t                kmsg_flags);
299 void ipc_port_release_send(ipc_port_t);
300 
301 #if DEVELOPMENT || DEBUG
302 void task_importance_update_owner_info(task_t);
303 #endif
304 
305 extern struct savearea *get_user_regs(thread_t);
306 
307 __attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
308 
309 #include <kern/thread.h>
310 #include <kern/task.h>
311 #include <kern/ast.h>
312 #include <kern/mach_loader.h>
313 #include <kern/mach_fat.h>
314 #include <mach-o/fat.h>
315 #include <mach-o/loader.h>
316 #include <machine/vmparam.h>
317 #include <sys/imgact.h>
318 
319 #include <sys/sdt.h>
320 
321 
322 /*
323  * EAI_ITERLIMIT	The maximum number of times to iterate an image
324  *			activator in exec_activate_image() before treating
325  *			it as malformed/corrupt.
326  */
327 #define EAI_ITERLIMIT           3
328 
329 /*
330  * For #! interpreter parsing
331  */
332 #define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
333 #define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
334 
335 extern vm_map_t bsd_pageable_map;
336 extern const struct fileops vnops;
337 extern int nextpidversion;
338 
339 
340 #define USER_ADDR_ALIGN(addr, val) \
341 	( ( (user_addr_t)(addr) + (val) - 1) \
342 	        & ~((val) - 1) )
343 
344 /*
345  * For subsystem root support
346  */
347 #define SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT "com.apple.private.spawn-subsystem-root"
348 
349 /*
350  * Allow setting p_crash_behavior to trigger panic on crash
351  */
352 #define SPAWN_SET_PANIC_CRASH_BEHAVIOR "com.apple.private.spawn-panic-crash-behavior"
353 
354 /* Platform Code Exec Logging */
355 static int platform_exec_logging = 0;
356 
357 SYSCTL_DECL(_security_mac);
358 
359 SYSCTL_INT(_security_mac, OID_AUTO, platform_exec_logging, CTLFLAG_RW, &platform_exec_logging, 0,
360     "log cdhashes for all platform binary executions");
361 
362 static os_log_t peLog = OS_LOG_DEFAULT;
363 
364 struct exception_port_action_t {
365 	ipc_port_t port;
366 	_ps_port_action_t *port_action;
367 };
368 
369 struct exec_port_actions {
370 	uint32_t exception_port_count;
371 	uint32_t portwatch_count;
372 	uint32_t registered_count;
373 	struct exception_port_action_t *excport_array;
374 	ipc_port_t *portwatch_array;
375 	ipc_port_t *registered_array;
376 };
377 
378 struct image_params;    /* Forward */
379 static int exec_activate_image(struct image_params *imgp);
380 static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
381 static int load_return_to_errno(load_return_t lrtn);
382 static int execargs_alloc(struct image_params *imgp);
383 static int execargs_free(struct image_params *imgp);
384 static int exec_check_permissions(struct image_params *imgp);
385 static int exec_extract_strings(struct image_params *imgp);
386 static int exec_add_apple_strings(struct image_params *imgp, const load_result_t *load_result);
387 static int exec_handle_sugid(struct image_params *imgp);
388 static int sugid_scripts = 0;
389 SYSCTL_INT(_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
390 static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
391 static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
392 static void exec_resettextvp(proc_t, struct image_params *);
393 static int process_signature(proc_t, struct image_params *);
394 static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
395 static errno_t exec_handle_port_actions(struct image_params *imgp,
396     struct exec_port_actions *port_actions);
397 static errno_t exec_handle_exception_port_actions(const struct image_params *imgp,
398     const struct exec_port_actions *port_actions);
399 static errno_t exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
400     task_role_t psa_darwin_role, struct exec_port_actions *port_actions);
401 static void exec_port_actions_destroy(struct exec_port_actions *port_actions);
402 
403 /*
404  * exec_add_user_string
405  *
406  * Add the requested string to the string space area.
407  *
408  * Parameters;	struct image_params *		image parameter block
409  *		user_addr_t			string to add to strings area
410  *		int				segment from which string comes
411  *		boolean_t			TRUE if string contributes to NCARGS
412  *
413  * Returns:	0			Success
414  *		!0			Failure errno from copyinstr()
415  *
416  * Implicit returns:
417  *		(imgp->ip_strendp)	updated location of next add, if any
418  *		(imgp->ip_strspace)	updated byte count of space remaining
419  *		(imgp->ip_argspace) updated byte count of space in NCARGS
420  */
421 __attribute__((noinline))
422 static int
exec_add_user_string(struct image_params * imgp,user_addr_t str,int seg,boolean_t is_ncargs)423 exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
424 {
425 	int error = 0;
426 
427 	do {
428 		size_t len = 0;
429 		int space;
430 
431 		if (is_ncargs) {
432 			space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
433 		} else {
434 			space = imgp->ip_strspace;
435 		}
436 
437 		if (space <= 0) {
438 			error = E2BIG;
439 			break;
440 		}
441 
442 		if (!UIO_SEG_IS_USER_SPACE(seg)) {
443 			char *kstr = CAST_DOWN(char *, str);     /* SAFE */
444 			error = copystr(kstr, imgp->ip_strendp, space, &len);
445 		} else {
446 			error = copyinstr(str, imgp->ip_strendp, space, &len);
447 		}
448 
449 		imgp->ip_strendp += len;
450 		imgp->ip_strspace -= len;
451 		if (is_ncargs) {
452 			imgp->ip_argspace -= len;
453 		}
454 	} while (error == ENAMETOOLONG);
455 
456 	return error;
457 }
458 
459 /*
460  * dyld is now passed the executable path as a getenv-like variable
461  * in the same fashion as the stack_guard and malloc_entropy keys.
462  */
463 #define EXECUTABLE_KEY "executable_path="
464 
465 /*
466  * exec_save_path
467  *
468  * To support new app package launching for Mac OS X, the dyld needs the
469  * first argument to execve() stored on the user stack.
470  *
471  * Save the executable path name at the bottom of the strings area and set
472  * the argument vector pointer to the location following that to indicate
473  * the start of the argument and environment tuples, setting the remaining
474  * string space count to the size of the string area minus the path length.
475  *
476  * Parameters;	struct image_params *		image parameter block
477  *		char *				path used to invoke program
478  *		int				segment from which path comes
479  *
480  * Returns:	int			0	Success
481  *		EFAULT				Bad address
482  *	copy[in]str:EFAULT			Bad address
483  *	copy[in]str:ENAMETOOLONG		Filename too long
484  *
485  * Implicit returns:
486  *		(imgp->ip_strings)		saved path
487  *		(imgp->ip_strspace)		space remaining in ip_strings
488  *		(imgp->ip_strendp)		start of remaining copy area
489  *		(imgp->ip_argspace)		space remaining of NCARGS
490  *		(imgp->ip_applec)		Initial applev[0]
491  *
492  * Note:	We have to do this before the initial namei() since in the
493  *		path contains symbolic links, namei() will overwrite the
494  *		original path buffer contents.  If the last symbolic link
495  *		resolved was a relative pathname, we would lose the original
496  *		"path", which could be an absolute pathname. This might be
497  *		unacceptable for dyld.
498  */
499 static int
exec_save_path(struct image_params * imgp,user_addr_t path,int seg,const char ** excpath)500 exec_save_path(struct image_params *imgp, user_addr_t path, int seg, const char **excpath)
501 {
502 	int error;
503 	size_t len;
504 	char *kpath;
505 
506 	// imgp->ip_strings can come out of a cache, so we need to obliterate the
507 	// old path.
508 	memset(imgp->ip_strings, '\0', strlen(EXECUTABLE_KEY) + MAXPATHLEN);
509 
510 	len = MIN(MAXPATHLEN, imgp->ip_strspace);
511 
512 	switch (seg) {
513 	case UIO_USERSPACE32:
514 	case UIO_USERSPACE64:   /* Same for copyin()... */
515 		error = copyinstr(path, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
516 		break;
517 	case UIO_SYSSPACE:
518 		kpath = CAST_DOWN(char *, path); /* SAFE */
519 		error = copystr(kpath, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
520 		break;
521 	default:
522 		error = EFAULT;
523 		break;
524 	}
525 
526 	if (!error) {
527 		bcopy(EXECUTABLE_KEY, imgp->ip_strings, strlen(EXECUTABLE_KEY));
528 		len += strlen(EXECUTABLE_KEY);
529 
530 		imgp->ip_strendp += len;
531 		imgp->ip_strspace -= len;
532 
533 		if (excpath) {
534 			*excpath = imgp->ip_strings + strlen(EXECUTABLE_KEY);
535 		}
536 	}
537 
538 	return error;
539 }
540 
541 /*
542  * exec_reset_save_path
543  *
544  * If we detect a shell script, we need to reset the string area
545  * state so that the interpreter can be saved onto the stack.
546  *
547  * Parameters;	struct image_params *		image parameter block
548  *
549  * Returns:	int			0	Success
550  *
551  * Implicit returns:
552  *		(imgp->ip_strings)		saved path
553  *		(imgp->ip_strspace)		space remaining in ip_strings
554  *		(imgp->ip_strendp)		start of remaining copy area
555  *		(imgp->ip_argspace)		space remaining of NCARGS
556  *
557  */
558 static int
exec_reset_save_path(struct image_params * imgp)559 exec_reset_save_path(struct image_params *imgp)
560 {
561 	imgp->ip_strendp = imgp->ip_strings;
562 	imgp->ip_argspace = NCARGS;
563 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
564 
565 	return 0;
566 }
567 
568 /*
569  * exec_shell_imgact
570  *
571  * Image activator for interpreter scripts.  If the image begins with
572  * the characters "#!", then it is an interpreter script.  Verify the
573  * length of the script line indicating the interpreter is not in
574  * excess of the maximum allowed size.  If this is the case, then
575  * break out the arguments, if any, which are separated by white
576  * space, and copy them into the argument save area as if they were
577  * provided on the command line before all other arguments.  The line
578  * ends when we encounter a comment character ('#') or newline.
579  *
580  * Parameters;	struct image_params *	image parameter block
581  *
582  * Returns:	-1			not an interpreter (keep looking)
583  *		-3			Success: interpreter: relookup
584  *		>0			Failure: interpreter: error number
585  *
586  * A return value other than -1 indicates subsequent image activators should
587  * not be given the opportunity to attempt to activate the image.
588  */
589 static int
exec_shell_imgact(struct image_params * imgp)590 exec_shell_imgact(struct image_params *imgp)
591 {
592 	char *vdata = imgp->ip_vdata;
593 	char *ihp;
594 	char *line_startp, *line_endp;
595 	char *interp;
596 
597 	/*
598 	 * Make sure it's a shell script.  If we've already redirected
599 	 * from an interpreted file once, don't do it again.
600 	 */
601 	if (vdata[0] != '#' ||
602 	    vdata[1] != '!' ||
603 	    (imgp->ip_flags & IMGPF_INTERPRET) != 0) {
604 		return -1;
605 	}
606 
607 	if (imgp->ip_origcputype != 0) {
608 		/* Fat header previously matched, don't allow shell script inside */
609 		return -1;
610 	}
611 
612 	imgp->ip_flags |= IMGPF_INTERPRET;
613 	imgp->ip_interp_sugid_fd = -1;
614 	imgp->ip_interp_buffer[0] = '\0';
615 
616 	/* Check to see if SUGID scripts are permitted.  If they aren't then
617 	 * clear the SUGID bits.
618 	 * imgp->ip_vattr is known to be valid.
619 	 */
620 	if (sugid_scripts == 0) {
621 		imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
622 	}
623 
624 	/* Try to find the first non-whitespace character */
625 	for (ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++) {
626 		if (IS_EOL(*ihp)) {
627 			/* Did not find interpreter, "#!\n" */
628 			return ENOEXEC;
629 		} else if (IS_WHITESPACE(*ihp)) {
630 			/* Whitespace, like "#!    /bin/sh\n", keep going. */
631 		} else {
632 			/* Found start of interpreter */
633 			break;
634 		}
635 	}
636 
637 	if (ihp == &vdata[IMG_SHSIZE]) {
638 		/* All whitespace, like "#!           " */
639 		return ENOEXEC;
640 	}
641 
642 	line_startp = ihp;
643 
644 	/* Try to find the end of the interpreter+args string */
645 	for (; ihp < &vdata[IMG_SHSIZE]; ihp++) {
646 		if (IS_EOL(*ihp)) {
647 			/* Got it */
648 			break;
649 		} else {
650 			/* Still part of interpreter or args */
651 		}
652 	}
653 
654 	if (ihp == &vdata[IMG_SHSIZE]) {
655 		/* A long line, like "#! blah blah blah" without end */
656 		return ENOEXEC;
657 	}
658 
659 	/* Backtrack until we find the last non-whitespace */
660 	while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
661 		ihp--;
662 	}
663 
664 	/* The character after the last non-whitespace is our logical end of line */
665 	line_endp = ihp + 1;
666 
667 	/*
668 	 * Now we have pointers to the usable part of:
669 	 *
670 	 * "#!  /usr/bin/int first    second   third    \n"
671 	 *      ^ line_startp                       ^ line_endp
672 	 */
673 
674 	/* copy the interpreter name */
675 	interp = imgp->ip_interp_buffer;
676 	for (ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++) {
677 		*interp++ = *ihp;
678 	}
679 	*interp = '\0';
680 
681 	exec_reset_save_path(imgp);
682 	exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
683 	    UIO_SYSSPACE, NULL);
684 
685 	/* Copy the entire interpreter + args for later processing into argv[] */
686 	interp = imgp->ip_interp_buffer;
687 	for (ihp = line_startp; (ihp < line_endp); ihp++) {
688 		*interp++ = *ihp;
689 	}
690 	*interp = '\0';
691 
692 #if CONFIG_SETUID
693 	/*
694 	 * If we have an SUID or SGID script, create a file descriptor
695 	 * from the vnode and pass /dev/fd/%d instead of the actual
696 	 * path name so that the script does not get opened twice
697 	 */
698 	if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
699 		proc_t p;
700 		struct fileproc *fp;
701 		int fd;
702 		int error;
703 
704 		p = vfs_context_proc(imgp->ip_vfs_context);
705 		error = falloc(p, &fp, &fd, imgp->ip_vfs_context);
706 		if (error) {
707 			return error;
708 		}
709 
710 		fp->fp_glob->fg_flag = FREAD;
711 		fp->fp_glob->fg_ops = &vnops;
712 		fp_set_data(fp, imgp->ip_vp);
713 
714 		proc_fdlock(p);
715 		procfdtbl_releasefd(p, fd, NULL);
716 		fp_drop(p, fd, fp, 1);
717 		proc_fdunlock(p);
718 		vnode_ref(imgp->ip_vp);
719 
720 		imgp->ip_interp_sugid_fd = fd;
721 	}
722 #endif /* CONFIG_SETUID */
723 
724 	return -3;
725 }
726 
727 
728 
729 /*
730  * exec_fat_imgact
731  *
732  * Image activator for fat 1.0 binaries.  If the binary is fat, then we
733  * need to select an image from it internally, and make that the image
734  * we are going to attempt to execute.  At present, this consists of
735  * reloading the first page for the image with a first page from the
736  * offset location indicated by the fat header.
737  *
738  * Parameters;	struct image_params *	image parameter block
739  *
740  * Returns:	-1			not a fat binary (keep looking)
741  *		-2			Success: encapsulated binary: reread
742  *		>0			Failure: error number
743  *
744  * Important:	This image activator is byte order neutral.
745  *
746  * Note:	A return value other than -1 indicates subsequent image
747  *		activators should not be given the opportunity to attempt
748  *		to activate the image.
749  *
750  *              If we find an encapsulated binary, we make no assertions
751  *		about its  validity; instead, we leave that up to a rescan
752  *		for an activator to claim it, and, if it is claimed by one,
753  *		that activator is responsible for determining validity.
754  */
755 static int
exec_fat_imgact(struct image_params * imgp)756 exec_fat_imgact(struct image_params *imgp)
757 {
758 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
759 	kauth_cred_t cred = kauth_cred_proc_ref(p);
760 	struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
761 	struct _posix_spawnattr *psa = NULL;
762 	struct fat_arch fat_arch;
763 	int resid, error;
764 	load_return_t lret;
765 
766 	if (imgp->ip_origcputype != 0) {
767 		/* Fat header previously matched, don't allow another fat file inside */
768 		error = -1; /* not claimed */
769 		goto bad;
770 	}
771 
772 	/* Make sure it's a fat binary */
773 	if (OSSwapBigToHostInt32(fat_header->magic) != FAT_MAGIC) {
774 		error = -1; /* not claimed */
775 		goto bad;
776 	}
777 
778 	/* imgp->ip_vdata has PAGE_SIZE, zerofilled if the file is smaller */
779 	lret = fatfile_validate_fatarches((vm_offset_t)fat_header, PAGE_SIZE,
780 	    (off_t)imgp->ip_vattr->va_data_size);
781 	if (lret != LOAD_SUCCESS) {
782 		error = load_return_to_errno(lret);
783 		goto bad;
784 	}
785 
786 	/* If posix_spawn binprefs exist, respect those prefs. */
787 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
788 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
789 		uint32_t pr = 0;
790 
791 		/* Check each preference listed against all arches in header */
792 		for (pr = 0; pr < NBINPREFS; pr++) {
793 			cpu_type_t pref = psa->psa_binprefs[pr];
794 			cpu_type_t subpref = psa->psa_subcpuprefs[pr];
795 
796 			if (pref == 0) {
797 				/* No suitable arch in the pref list */
798 				error = EBADARCH;
799 				goto bad;
800 			}
801 
802 			if (pref == CPU_TYPE_ANY) {
803 				/* Fall through to regular grading */
804 				goto regular_grading;
805 			}
806 
807 			lret = fatfile_getbestarch_for_cputype(pref,
808 			    subpref,
809 			    (vm_offset_t)fat_header,
810 			    PAGE_SIZE,
811 			    imgp,
812 			    &fat_arch);
813 			if (lret == LOAD_SUCCESS) {
814 				goto use_arch;
815 			}
816 		}
817 
818 		/* Requested binary preference was not honored */
819 		error = EBADEXEC;
820 		goto bad;
821 	}
822 
823 regular_grading:
824 	/* Look up our preferred architecture in the fat file. */
825 	lret = fatfile_getbestarch((vm_offset_t)fat_header,
826 	    PAGE_SIZE,
827 	    imgp,
828 	    &fat_arch,
829 	    (p->p_flag & P_AFFINITY) != 0);
830 	if (lret != LOAD_SUCCESS) {
831 		error = load_return_to_errno(lret);
832 		goto bad;
833 	}
834 
835 use_arch:
836 	/* Read the Mach-O header out of fat_arch */
837 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
838 	    PAGE_SIZE, fat_arch.offset,
839 	    UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
840 	    cred, &resid, p);
841 	if (error) {
842 		goto bad;
843 	}
844 
845 	if (resid) {
846 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
847 	}
848 
849 	/* Success.  Indicate we have identified an encapsulated binary */
850 	error = -2;
851 	imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
852 	imgp->ip_arch_size = (user_size_t)fat_arch.size;
853 	imgp->ip_origcputype = fat_arch.cputype;
854 	imgp->ip_origcpusubtype = fat_arch.cpusubtype;
855 
856 bad:
857 	kauth_cred_unref(&cred);
858 	return error;
859 }
860 
861 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)862 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
863 {
864 	int ret;
865 
866 	(void)task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0);
867 	task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
868 	if (result->is_64bit_addr) {
869 		OSBitOrAtomic(P_LP64, &p->p_flag);
870 		get_bsdthread_info(thread)->uu_flag |= UT_LP64;
871 	} else {
872 		OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
873 		get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
874 	}
875 	task_set_mach_header_address(task, result->mach_header);
876 
877 	ret = thread_state_initialize(thread);
878 	if (ret != KERN_SUCCESS) {
879 		return ret;
880 	}
881 
882 	if (result->threadstate) {
883 		uint32_t *ts = result->threadstate;
884 		uint32_t total_size = (uint32_t)result->threadstate_sz;
885 
886 		while (total_size > 0) {
887 			uint32_t flavor = *ts++;
888 			uint32_t size = *ts++;
889 
890 			ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
891 			if (ret) {
892 				return ret;
893 			}
894 			ts += size;
895 			total_size -= (size + 2) * sizeof(uint32_t);
896 		}
897 	}
898 
899 	thread_setentrypoint(thread, result->entry_point);
900 
901 	return KERN_SUCCESS;
902 }
903 
904 #if (DEVELOPMENT || DEBUG)
905 extern char panic_on_proc_crash[];
906 extern int use_panic_on_proc_crash;
907 
908 extern char panic_on_proc_exit[];
909 extern int use_panic_on_proc_exit;
910 
911 extern char panic_on_proc_spawn_fail[];
912 extern int use_panic_on_proc_spawn_fail;
913 #endif
914 
915 void
set_proc_name(struct image_params * imgp,proc_t p)916 set_proc_name(struct image_params *imgp, proc_t p)
917 {
918 	int p_name_len = sizeof(p->p_name) - 1;
919 
920 	if (imgp->ip_ndp->ni_cnd.cn_namelen > p_name_len) {
921 		imgp->ip_ndp->ni_cnd.cn_namelen = p_name_len;
922 	}
923 
924 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name,
925 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
926 	p->p_name[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
927 
928 	if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN) {
929 		imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
930 	}
931 
932 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
933 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
934 	p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
935 
936 #if DEVELOPMENT || DEBUG
937 	/*
938 	 * This happens during image activation, so the crash behavior flags from
939 	 * posix_spawn will have already been set. So we don't have to worry about
940 	 * this being overridden.
941 	 */
942 	if (use_panic_on_proc_crash && strcmp(p->p_comm, panic_on_proc_crash) == 0) {
943 		printf("will panic on proc crash: %s\n", p->p_comm);
944 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_CRASH;
945 	}
946 
947 	if (use_panic_on_proc_exit && strcmp(p->p_comm, panic_on_proc_exit) == 0) {
948 		printf("will panic on proc exit: %s\n", p->p_comm);
949 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_EXIT;
950 	}
951 
952 	if (use_panic_on_proc_spawn_fail && strcmp(p->p_comm, panic_on_proc_spawn_fail) == 0) {
953 		printf("will panic on proc spawn fail: %s\n", p->p_comm);
954 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_SPAWN_FAIL;
955 	}
956 #endif
957 }
958 
959 #if __has_feature(ptrauth_calls)
960 /**
961  * Returns a team ID string that may be used to assign a shared region.
962  *
963  * Platform binaries do not have team IDs and will return NULL.  Non-platform
964  * binaries without a team ID will be assigned an artificial team ID of ""
965  * (empty string) so that they will not be assigned to the default shared
966  * region.
967  *
968  * @param imgp image parameter block
969  * @return NULL if this is a platform binary, or an appropriate team ID string
970  *         otherwise
971  */
972 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)973 get_teamid_for_shared_region(struct image_params *imgp)
974 {
975 	assert(imgp->ip_vp != NULL);
976 
977 	const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
978 	if (ret) {
979 		return ret;
980 	}
981 
982 	struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
983 	if (csblob_get_platform_binary(blob)) {
984 		return NULL;
985 	} else {
986 		static const char *NO_TEAM_ID = "";
987 		return NO_TEAM_ID;
988 	}
989 }
990 
991 /**
992  * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
993  *
994  * @param cpusubtype Mach-O style CPU subtype
995  * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
996  */
997 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)998 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
999 {
1000 	return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1001 	       CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
1002 }
1003 
1004 #endif /* __has_feature(ptrauth_calls) */
1005 
1006 /**
1007  * Returns whether a type/subtype slice matches the requested
1008  * type/subtype.
1009  *
1010  * @param mask Bits to mask from the requested/tested cpu type
1011  * @param req_cpu Requested cpu type
1012  * @param req_subcpu Requested cpu subtype
1013  * @param test_cpu Tested slice cpu type
1014  * @param test_subcpu Tested slice cpu subtype
1015  */
1016 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)1017 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
1018     cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
1019     cpu_subtype_t test_subcpu)
1020 {
1021 	if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
1022 		return FALSE;
1023 	}
1024 
1025 	test_subcpu &= ~CPU_SUBTYPE_MASK;
1026 	req_subcpu  &= ~CPU_SUBTYPE_MASK;
1027 
1028 	if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
1029 		return FALSE;
1030 	}
1031 
1032 	return TRUE;
1033 }
1034 
1035 
1036 #define MIN_IOS_TPRO_SDK_VERSION        0x00100000
1037 #define MIN_OSX_TPRO_SDK_VERSION        0x000D0000
1038 #define MIN_TVOS_TPRO_SDK_VERSION       0x000D0000
1039 #define MIN_WATCHOS_TPRO_SDK_VERSION    0x00090000
1040 #define MIN_DRIVERKIT_TPRO_SDK_VERSION  0x00600000
1041 
1042 static void
exec_setup_tpro(struct image_params * imgp,load_result_t * load_result)1043 exec_setup_tpro(struct image_params *imgp, load_result_t *load_result)
1044 {
1045 	extern boolean_t xprr_tpro_enabled;
1046 	extern boolean_t enable_user_modifiable_perms;
1047 	uint32_t min_sdk_version = 0;
1048 
1049 	/* x86-64 translated code cannot take advantage of TPRO */
1050 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1051 		return;
1052 	}
1053 
1054 	/* Do not enable on 32-bit VA targets */
1055 	if (!(imgp->ip_flags & IMGPF_IS_64BIT_ADDR)) {
1056 		return;
1057 	}
1058 
1059 	switch (load_result->ip_platform) {
1060 	case PLATFORM_IOS:
1061 	case PLATFORM_IOSSIMULATOR:
1062 	case PLATFORM_MACCATALYST:
1063 		min_sdk_version = MIN_IOS_TPRO_SDK_VERSION;
1064 		break;
1065 	case PLATFORM_MACOS:
1066 		min_sdk_version = MIN_OSX_TPRO_SDK_VERSION;
1067 		break;
1068 	case PLATFORM_TVOS:
1069 	case PLATFORM_TVOSSIMULATOR:
1070 		min_sdk_version = MIN_TVOS_TPRO_SDK_VERSION;
1071 		break;
1072 	case PLATFORM_WATCHOS:
1073 	case PLATFORM_WATCHOSSIMULATOR:
1074 		min_sdk_version = MIN_WATCHOS_TPRO_SDK_VERSION;
1075 		break;
1076 	case PLATFORM_DRIVERKIT:
1077 		min_sdk_version = MIN_DRIVERKIT_TPRO_SDK_VERSION;
1078 		break;
1079 	default:
1080 		/* TPRO is on by default for newer platforms */
1081 		break;
1082 	}
1083 
1084 }
1085 
1086 /*
1087  * If the passed in executable's vnode should use the RSR
1088  * shared region, then this should return TRUE, otherwise, return FALSE.
1089  */
1090 static uint32_t rsr_current_version = 0;
1091 boolean_t (*rsr_check_vnode)(void *vnode) = NULL;
1092 
1093 boolean_t
vnode_is_rsr(vnode_t vp)1094 vnode_is_rsr(vnode_t vp)
1095 {
1096 	if (!(vnode_isreg(vp) && vnode_tag(vp) == VT_APFS)) {
1097 		return FALSE;
1098 	}
1099 
1100 	if (rsr_check_vnode != NULL && rsr_check_vnode((void *)vp)) {
1101 		return TRUE;
1102 	}
1103 	return FALSE;
1104 }
1105 
1106 
1107 uint32_t
rsr_get_version(void)1108 rsr_get_version(void)
1109 {
1110 	return os_atomic_load(&rsr_current_version, relaxed);
1111 }
1112 
1113 void
rsr_bump_version(void)1114 rsr_bump_version(void)
1115 {
1116 	os_atomic_inc(&rsr_current_version, relaxed);
1117 }
1118 
1119 #if XNU_TARGET_OS_OSX
1120 static int
1121 rsr_version_sysctl SYSCTL_HANDLER_ARGS
1122 {
1123 #pragma unused(arg1, arg2, oidp)
1124 	int value = rsr_get_version();
1125 	int error = SYSCTL_OUT(req, &value, sizeof(int));
1126 	if (error) {
1127 		return error;
1128 	}
1129 
1130 	if (!req->newptr) {
1131 		return 0;
1132 	}
1133 
1134 	error = SYSCTL_IN(req, &value, sizeof(int));
1135 	if (error) {
1136 		return error;
1137 	}
1138 	if (value != 0) {
1139 		rsr_bump_version();
1140 	}
1141 	return 0;
1142 }
1143 
1144 
1145 SYSCTL_PROC(_vm, OID_AUTO, shared_region_control,
1146     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
1147     0, 0, rsr_version_sysctl, "I", "");
1148 #endif /* XNU_TARGET_OS_OSX */
1149 
1150 /*
1151  * exec_mach_imgact
1152  *
1153  * Image activator for mach-o 1.0 binaries.
1154  *
1155  * Parameters;	struct image_params *	image parameter block
1156  *
1157  * Returns:	-1			not a fat binary (keep looking)
1158  *		-2			Success: encapsulated binary: reread
1159  *		>0			Failure: error number
1160  *		EBADARCH		Mach-o binary, but with an unrecognized
1161  *					architecture
1162  *		ENOMEM			No memory for child process after -
1163  *					can only happen after vfork()
1164  *
1165  * Important:	This image activator is NOT byte order neutral.
1166  *
1167  * Note:	A return value other than -1 indicates subsequent image
1168  *		activators should not be given the opportunity to attempt
1169  *		to activate the image.
1170  */
1171 static int
exec_mach_imgact(struct image_params * imgp)1172 exec_mach_imgact(struct image_params *imgp)
1173 {
1174 	struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1175 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
1176 	int                     error = 0;
1177 	task_t                  task;
1178 	task_t                  new_task = NULL; /* protected by vfexec */
1179 	thread_t                thread;
1180 	struct uthread          *uthread;
1181 	vm_map_t old_map = VM_MAP_NULL;
1182 	vm_map_t map = VM_MAP_NULL;
1183 	load_return_t           lret;
1184 	load_result_t           load_result = {};
1185 	struct _posix_spawnattr *psa = NULL;
1186 	int                     spawn = (imgp->ip_flags & IMGPF_SPAWN);
1187 	const int               vfexec = 0;
1188 	int                     exec = (imgp->ip_flags & IMGPF_EXEC);
1189 	os_reason_t             exec_failure_reason = OS_REASON_NULL;
1190 	boolean_t               reslide = FALSE;
1191 	char *                  userspace_coredump_name = NULL;
1192 
1193 	/*
1194 	 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1195 	 * is a reserved field on the end, so for the most part, we can
1196 	 * treat them as if they were identical. Reverse-endian Mach-O
1197 	 * binaries are recognized but not compatible.
1198 	 */
1199 	if ((mach_header->magic == MH_CIGAM) ||
1200 	    (mach_header->magic == MH_CIGAM_64)) {
1201 		error = EBADARCH;
1202 		goto bad;
1203 	}
1204 
1205 	if ((mach_header->magic != MH_MAGIC) &&
1206 	    (mach_header->magic != MH_MAGIC_64)) {
1207 		error = -1;
1208 		goto bad;
1209 	}
1210 
1211 	if (mach_header->filetype != MH_EXECUTE) {
1212 		error = -1;
1213 		goto bad;
1214 	}
1215 
1216 	if (imgp->ip_origcputype != 0) {
1217 		/* Fat header previously had an idea about this thin file */
1218 		if (imgp->ip_origcputype != mach_header->cputype ||
1219 		    imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1220 			error = EBADARCH;
1221 			goto bad;
1222 		}
1223 	} else {
1224 		imgp->ip_origcputype = mach_header->cputype;
1225 		imgp->ip_origcpusubtype = mach_header->cpusubtype;
1226 	}
1227 
1228 	task = current_task();
1229 	thread = current_thread();
1230 	uthread = get_bsdthread_info(thread);
1231 
1232 	if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1233 		imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1234 	}
1235 
1236 
1237 	/* If posix_spawn binprefs exist, respect those prefs. */
1238 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1239 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
1240 		int pr = 0;
1241 		for (pr = 0; pr < NBINPREFS; pr++) {
1242 			cpu_type_t pref = psa->psa_binprefs[pr];
1243 			cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1244 
1245 			if (pref == 0) {
1246 				/* No suitable arch in the pref list */
1247 				error = EBADARCH;
1248 				goto bad;
1249 			}
1250 
1251 			if (pref == CPU_TYPE_ANY) {
1252 				/* Jump to regular grading */
1253 				goto grade;
1254 			}
1255 
1256 			if (binary_match(CPU_ARCH_MASK, pref, subpref,
1257 			    imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1258 				goto grade;
1259 			}
1260 		}
1261 		error = EBADARCH;
1262 		goto bad;
1263 	}
1264 grade:
1265 	if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1266 	    imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1267 		error = EBADARCH;
1268 		goto bad;
1269 	}
1270 
1271 	if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1272 	    imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1273 #if __x86_64__
1274 		const char *excpath;
1275 		error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1276 		os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1277 #endif
1278 		error = EBADARCH;
1279 		goto bad;
1280 	}
1281 
1282 #if defined(HAS_APPLE_PAC)
1283 	assert(mach_header->cputype == CPU_TYPE_ARM64
1284 	    );
1285 
1286 	if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1287 	    arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1288 	    ) {
1289 		imgp->ip_flags &= ~IMGPF_NOJOP;
1290 	} else {
1291 		imgp->ip_flags |= IMGPF_NOJOP;
1292 	}
1293 #endif
1294 
1295 	/* Copy in arguments/environment from the old process */
1296 	error = exec_extract_strings(imgp);
1297 	if (error) {
1298 		goto bad;
1299 	}
1300 
1301 	AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1302 	    imgp->ip_endargv - imgp->ip_startargv);
1303 	AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1304 	    imgp->ip_endenvv - imgp->ip_endargv);
1305 
1306 
1307 
1308 	/* reset local idea of thread, uthread, task */
1309 	thread = imgp->ip_new_thread;
1310 	uthread = get_bsdthread_info(thread);
1311 	task = new_task = get_threadtask(thread);
1312 
1313 	/*
1314 	 *	Load the Mach-O file.
1315 	 *
1316 	 * NOTE: An error after this point  indicates we have potentially
1317 	 * destroyed or overwritten some process state while attempting an
1318 	 * execve() following a vfork(), which is an unrecoverable condition.
1319 	 * We send the new process an immediate SIGKILL to avoid it executing
1320 	 * any instructions in the mutated address space. For true spawns,
1321 	 * this is not the case, and "too late" is still not too late to
1322 	 * return an error code to the parent process.
1323 	 */
1324 
1325 	/*
1326 	 * Actually load the image file we previously decided to load.
1327 	 */
1328 	lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1329 	if (lret != LOAD_SUCCESS) {
1330 		error = load_return_to_errno(lret);
1331 
1332 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1333 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1334 		if (lret == LOAD_BADMACHO_UPX) {
1335 			set_proc_name(imgp, p);
1336 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1337 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1338 		} else {
1339 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1340 
1341 			if (bootarg_execfailurereports) {
1342 				set_proc_name(imgp, p);
1343 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1344 			}
1345 		}
1346 
1347 		exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1348 
1349 		goto badtoolate;
1350 	}
1351 
1352 	/*
1353 	 * ERROR RECOVERY
1354 	 *
1355 	 * load_machfile() returned the new VM map ("map") but we haven't
1356 	 * committed to it yet.
1357 	 * Any error path between here and the point where we commit to using
1358 	 * the new "map" (with swap_task_map()) should deallocate "map".
1359 	 */
1360 
1361 #ifndef KASAN
1362 	/*
1363 	 * Security: zone sanity checks on fresh boot or initproc re-exec.
1364 	 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1365 	 * which means here is the earliest point we can assert on empty service port label zone,
1366 	 * after load_machfile() above terminates old launchd's IPC space.
1367 	 *
1368 	 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1369 	 * under quarantine.
1370 	 */
1371 	if (task_pid(task) == 1) {
1372 		zone_userspace_reboot_checks();
1373 	}
1374 #endif
1375 
1376 	proc_lock(p);
1377 	p->p_cputype = imgp->ip_origcputype;
1378 	p->p_cpusubtype = imgp->ip_origcpusubtype;
1379 	proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1380 	exec_setup_tpro(imgp, &load_result);
1381 
1382 	vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1383 	vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1384 	vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1385 #if XNU_TARGET_OS_OSX
1386 	if (proc_platform(p) == PLATFORM_IOS) {
1387 		assert(vm_map_is_alien(map));
1388 	} else {
1389 		assert(!vm_map_is_alien(map));
1390 	}
1391 #endif /* XNU_TARGET_OS_OSX */
1392 	proc_unlock(p);
1393 
1394 	/*
1395 	 * Set TPRO flags if enabled
1396 	 */
1397 
1398 	/*
1399 	 * Set code-signing flags if this binary is signed, or if parent has
1400 	 * requested them on exec.
1401 	 */
1402 	if (load_result.csflags & CS_VALID) {
1403 		imgp->ip_csflags |= load_result.csflags &
1404 		    (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1405 		    CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1406 		    CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1407 		    CS_ENTITLEMENT_FLAGS |
1408 		    CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1409 	} else {
1410 		imgp->ip_csflags &= ~CS_VALID;
1411 	}
1412 
1413 	if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1414 		imgp->ip_csflags |= CS_HARD;
1415 	}
1416 	if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1417 		imgp->ip_csflags |= CS_KILL;
1418 	}
1419 	if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1420 		imgp->ip_csflags |= CS_ENFORCEMENT;
1421 	}
1422 	if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1423 		if (proc_getcsflags(p) & CS_INSTALLER) {
1424 			imgp->ip_csflags |= CS_INSTALLER;
1425 		}
1426 		if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1427 			imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1428 		}
1429 		if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1430 			imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1431 		}
1432 	}
1433 
1434 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1435 	/*
1436 	 * ptrauth version 0 is a preview ABI.  Developers can opt into running
1437 	 * their own arm64e binaries for local testing, with the understanding
1438 	 * that future OSes may break ABI.
1439 	 */
1440 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1441 	    CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1442 	    !load_result.platform_binary &&
1443 	    !bootarg_arm64e_preview_abi) {
1444 		static bool logged_once = false;
1445 		set_proc_name(imgp, p);
1446 
1447 		printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1448 		if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1449 			printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1450 		}
1451 
1452 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1453 		if (bootarg_execfailurereports) {
1454 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1455 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1456 		}
1457 
1458 		/* release new address space since we won't use it */
1459 		imgp->ip_free_map = map;
1460 		map = VM_MAP_NULL;
1461 		goto badtoolate;
1462 	}
1463 
1464 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1465 	    imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1466 	    load_result.platform_binary &&
1467 	    (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1468 		set_proc_name(imgp, p);
1469 		printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
1470 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1471 		if (bootarg_execfailurereports) {
1472 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1473 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1474 		}
1475 
1476 		/* release new address space since we won't use it */
1477 		imgp->ip_free_map = map;
1478 		map = VM_MAP_NULL;
1479 		goto badtoolate;
1480 	}
1481 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1482 
1483 
1484 	/*
1485 	 * Set up the shared cache region in the new process.
1486 	 *
1487 	 * Normally there is a single shared region per architecture.
1488 	 * However on systems with Pointer Authentication, we can create
1489 	 * multiple shared caches with the amount of sharing determined
1490 	 * by team-id or entitlement. Inherited shared region IDs are used
1491 	 * for system processes that need to match and be able to inspect
1492 	 * a pre-existing task.
1493 	 */
1494 	int cpu_subtype = 0; /* all cpu_subtypes use the same shared region */
1495 #if __has_feature(ptrauth_calls)
1496 	char *shared_region_id = NULL;
1497 	size_t len;
1498 	char *base;
1499 	const char *cbase;
1500 #define TEAM_ID_PREFIX "T-"
1501 #define ENTITLE_PREFIX "E-"
1502 #define SR_PREFIX_LEN  2
1503 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1504 
1505 	if (cpu_type() == CPU_TYPE_ARM64 &&
1506 	    arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1507 	    (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1508 		assertf(p->p_cputype == CPU_TYPE_ARM64,
1509 		    "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1510 		    p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1511 
1512 		/*
1513 		 * arm64e uses pointer authentication, so request a separate
1514 		 * shared region for this CPU subtype.
1515 		 */
1516 		cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1517 
1518 		/*
1519 		 * Determine which shared cache to select based on being told,
1520 		 * matching a team-id or matching an entitlement.
1521 		 */
1522 		if (imgp->ip_inherited_shared_region_id) {
1523 			len = strlen(imgp->ip_inherited_shared_region_id);
1524 			shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1525 			memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1526 		} else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1527 			len = strlen(cbase);
1528 			if (vm_shared_region_per_team_id) {
1529 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1530 				    Z_WAITOK | Z_NOFAIL);
1531 				memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1532 				memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1533 			}
1534 		} else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1535 		    (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1536 			len = strlen(base);
1537 			if (vm_shared_region_by_entitlement) {
1538 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1539 				    Z_WAITOK | Z_NOFAIL);
1540 				memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1541 				memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1542 			}
1543 			/* Discard the copy of the entitlement */
1544 			kfree_data(base, len + 1);
1545 		}
1546 	}
1547 
1548 	if (imgp->ip_flags & IMGPF_RESLIDE) {
1549 		reslide = TRUE;
1550 	}
1551 
1552 	/* use "" as the default shared_region_id */
1553 	if (shared_region_id == NULL) {
1554 		shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1555 	}
1556 
1557 	/* ensure there's a unique pointer signing key for this shared_region_id */
1558 	shared_region_key_alloc(shared_region_id,
1559 	    imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1560 	task_set_shared_region_id(task, shared_region_id);
1561 	shared_region_id = NULL;
1562 #endif /* __has_feature(ptrauth_calls) */
1563 
1564 #if CONFIG_ROSETTA
1565 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1566 		OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
1567 	} else if (p->p_flag & P_TRANSLATED) {
1568 		OSBitAndAtomic(~P_TRANSLATED, &p->p_flag);
1569 	}
1570 #endif
1571 
1572 	int cputype = cpu_type();
1573 
1574 	uint32_t rsr_version = 0;
1575 #if XNU_TARGET_OS_OSX
1576 	if (vnode_is_rsr(imgp->ip_vp)) {
1577 		rsr_version = rsr_get_version();
1578 		os_atomic_or(&p->p_ladvflag, P_RSR, relaxed);
1579 		os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_ALTLINK, relaxed);
1580 	}
1581 #endif /* XNU_TARGET_OS_OSX */
1582 
1583 	vm_map_exec(map, task, load_result.is_64bit_addr,
1584 	    (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide,
1585 	    (imgp->ip_flags & IMGPF_DRIVER) != 0,
1586 	    rsr_version);
1587 
1588 	/*
1589 	 * Close file descriptors which specify close-on-exec.
1590 	 */
1591 	fdt_exec(p, psa != NULL ? psa->psa_flags : 0, imgp->ip_new_thread, exec);
1592 
1593 	/*
1594 	 * deal with set[ug]id.
1595 	 */
1596 	error = exec_handle_sugid(imgp);
1597 	if (error) {
1598 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1599 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1600 
1601 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1602 		if (bootarg_execfailurereports) {
1603 			set_proc_name(imgp, p);
1604 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1605 		}
1606 
1607 		/* release new address space since we won't use it */
1608 		imgp->ip_free_map = map;
1609 		map = VM_MAP_NULL;
1610 		goto badtoolate;
1611 	}
1612 
1613 	/*
1614 	 * Commit to new map.
1615 	 *
1616 	 * Swap the new map for the old for target task, which consumes
1617 	 * our new map reference but each leaves us responsible for the
1618 	 * old_map reference.  That lets us get off the pmap associated
1619 	 * with it, and then we can release it.
1620 	 *
1621 	 * The map needs to be set on the target task which is different
1622 	 * than current task, thus swap_task_map is used instead of
1623 	 * vm_map_switch.
1624 	 */
1625 	old_map = swap_task_map(task, thread, map);
1626 #if MACH_ASSERT
1627 	/*
1628 	 * Reset the pmap's process info to prevent ledger checks
1629 	 * which might fail due to the ledgers being shared between
1630 	 * the old and new pmaps.
1631 	 */
1632 	vm_map_pmap_set_process(old_map, -1, "<old_map>");
1633 #endif /* MACH_ASSERT */
1634 	imgp->ip_free_map = old_map;
1635 	old_map = NULL;
1636 
1637 	lret = activate_exec_state(task, p, thread, &load_result);
1638 	if (lret != KERN_SUCCESS) {
1639 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1640 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1641 
1642 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1643 		if (bootarg_execfailurereports) {
1644 			set_proc_name(imgp, p);
1645 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1646 		}
1647 
1648 		goto badtoolate;
1649 	}
1650 
1651 	/*
1652 	 * deal with voucher on exec-calling thread.
1653 	 */
1654 	if (imgp->ip_new_thread == NULL) {
1655 		thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1656 	}
1657 
1658 	/* Make sure we won't interrupt ourself signalling a partial process */
1659 	if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1660 		psignal(p, SIGTRAP);
1661 	}
1662 
1663 	if (load_result.unixproc &&
1664 	    create_unix_stack(get_task_map(task),
1665 	    &load_result,
1666 	    p) != KERN_SUCCESS) {
1667 		error = load_return_to_errno(LOAD_NOSPACE);
1668 
1669 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1670 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1671 
1672 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1673 		if (bootarg_execfailurereports) {
1674 			set_proc_name(imgp, p);
1675 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1676 		}
1677 
1678 		goto badtoolate;
1679 	}
1680 
1681 	/*
1682 	 * The load result will have already been munged by AMFI to include the
1683 	 * platform binary flag if boot-args dictated it (AMFI will mark anything
1684 	 * that doesn't go through the upcall path as a platform binary if its
1685 	 * enforcement is disabled).
1686 	 */
1687 	if (load_result.platform_binary) {
1688 		if (cs_debug) {
1689 			printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1690 		}
1691 
1692 		/*
1693 		 * We must use 'task' here because the proc's task has not yet been
1694 		 * switched to the new one.
1695 		 */
1696 		task_set_platform_binary(task, TRUE);
1697 	} else {
1698 		if (cs_debug) {
1699 			printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1700 		}
1701 
1702 		task_set_platform_binary(task, FALSE);
1703 	}
1704 
1705 
1706 	/*
1707 	 * Set starting EXC_GUARD and control port behavior for task now that
1708 	 * platform is set. Use the name directly from imgp since we haven't
1709 	 * set_proc_name() yet. Also make control port for the task and main thread
1710 	 * immovable/pinned based on task's option.
1711 	 *
1712 	 * Must happen before main thread port copyout in exc_add_apple_strings.
1713 	 */
1714 	task_set_exc_guard_ctrl_port_default(task, thread,
1715 	    imgp->ip_ndp->ni_cnd.cn_nameptr,
1716 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1717 	    proc_is_simulated(p),
1718 	    load_result.ip_platform,
1719 	    load_result.lr_sdk);
1720 
1721 	error = exec_add_apple_strings(imgp, &load_result); /* copies out main thread port */
1722 
1723 	if (error) {
1724 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1725 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
1726 
1727 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
1728 		if (bootarg_execfailurereports) {
1729 			set_proc_name(imgp, p);
1730 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1731 		}
1732 		goto badtoolate;
1733 	}
1734 
1735 	/* Switch to target task's map to copy out strings */
1736 	old_map = vm_map_switch(get_task_map(task));
1737 
1738 	if (load_result.unixproc) {
1739 		user_addr_t     ap;
1740 
1741 		/*
1742 		 * Copy the strings area out into the new process address
1743 		 * space.
1744 		 */
1745 		ap = p->user_stack;
1746 		error = exec_copyout_strings(imgp, &ap);
1747 		if (error) {
1748 			vm_map_switch(old_map);
1749 
1750 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1751 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
1752 
1753 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
1754 			if (bootarg_execfailurereports) {
1755 				set_proc_name(imgp, p);
1756 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1757 			}
1758 			goto badtoolate;
1759 		}
1760 		/* Set the stack */
1761 		thread_setuserstack(thread, ap);
1762 	}
1763 
1764 	if (load_result.dynlinker || load_result.is_rosetta) {
1765 		user_addr_t        ap;
1766 		int                     new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
1767 
1768 		/* Adjust the stack */
1769 		ap = thread_adjuserstack(thread, -new_ptr_size);
1770 		error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
1771 
1772 		if (error) {
1773 			vm_map_switch(old_map);
1774 
1775 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1776 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
1777 
1778 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
1779 			if (bootarg_execfailurereports) {
1780 				set_proc_name(imgp, p);
1781 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1782 			}
1783 			goto badtoolate;
1784 		}
1785 		error = task_set_dyld_info(task, load_result.all_image_info_addr,
1786 		    load_result.all_image_info_size);
1787 		if (error) {
1788 			vm_map_switch(old_map);
1789 
1790 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1791 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
1792 
1793 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1794 			if (bootarg_execfailurereports) {
1795 				set_proc_name(imgp, p);
1796 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1797 			}
1798 			error = EINVAL;
1799 			goto badtoolate;
1800 		}
1801 	}
1802 
1803 #if CONFIG_ROSETTA
1804 	if (load_result.is_rosetta) {
1805 		// Add an fd for the executable file for Rosetta's use
1806 		int main_binary_fd;
1807 		struct fileproc *fp;
1808 
1809 		error = falloc(p, &fp, &main_binary_fd, imgp->ip_vfs_context);
1810 		if (error) {
1811 			vm_map_switch(old_map);
1812 
1813 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1814 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1815 
1816 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1817 			if (bootarg_execfailurereports) {
1818 				set_proc_name(imgp, p);
1819 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1820 			}
1821 			goto badtoolate;
1822 		}
1823 
1824 		error = VNOP_OPEN(imgp->ip_vp, FREAD, imgp->ip_vfs_context);
1825 		if (error) {
1826 			vm_map_switch(old_map);
1827 
1828 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1829 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1830 
1831 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1832 			if (bootarg_execfailurereports) {
1833 				set_proc_name(imgp, p);
1834 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1835 			}
1836 			goto cleanup_rosetta_fp;
1837 		}
1838 
1839 		fp->fp_glob->fg_flag = FREAD;
1840 		fp->fp_glob->fg_ops = &vnops;
1841 		fp_set_data(fp, imgp->ip_vp);
1842 
1843 		proc_fdlock(p);
1844 		procfdtbl_releasefd(p, main_binary_fd, NULL);
1845 		fp_drop(p, main_binary_fd, fp, 1);
1846 		proc_fdunlock(p);
1847 
1848 		vnode_ref(imgp->ip_vp);
1849 
1850 		// Pass the dyld load address, main binary fd, and dyld fd on the stack
1851 		uint64_t ap = thread_adjuserstack(thread, -24);
1852 
1853 		error = copyoutptr((user_addr_t)load_result.dynlinker_fd, ap, 8);
1854 		if (error) {
1855 			vm_map_switch(old_map);
1856 
1857 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1858 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1859 
1860 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1861 			if (bootarg_execfailurereports) {
1862 				set_proc_name(imgp, p);
1863 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1864 			}
1865 			goto cleanup_rosetta_fp;
1866 		}
1867 
1868 		error = copyoutptr(load_result.dynlinker_mach_header, ap + 8, 8);
1869 		if (error) {
1870 			vm_map_switch(old_map);
1871 
1872 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1873 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1874 
1875 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1876 			if (bootarg_execfailurereports) {
1877 				set_proc_name(imgp, p);
1878 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1879 			}
1880 			goto cleanup_rosetta_fp;
1881 		}
1882 
1883 		error = copyoutptr((user_addr_t)main_binary_fd, ap + 16, 8);
1884 		if (error) {
1885 			vm_map_switch(old_map);
1886 
1887 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1888 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1889 
1890 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1891 			if (bootarg_execfailurereports) {
1892 				set_proc_name(imgp, p);
1893 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1894 			}
1895 			goto cleanup_rosetta_fp;
1896 		}
1897 
1898 cleanup_rosetta_fp:
1899 		if (error) {
1900 			fp_free(p, load_result.dynlinker_fd, load_result.dynlinker_fp);
1901 			fp_free(p, main_binary_fd, fp);
1902 			goto badtoolate;
1903 		}
1904 	}
1905 
1906 #endif
1907 
1908 	/* Avoid immediate VM faults back into kernel */
1909 	exec_prefault_data(p, imgp, &load_result);
1910 
1911 	vm_map_switch(old_map);
1912 
1913 	/*
1914 	 * Reset signal state.
1915 	 */
1916 	execsigs(p, thread);
1917 
1918 	/*
1919 	 * need to cancel async IO requests that can be cancelled and wait for those
1920 	 * already active.  MAY BLOCK!
1921 	 */
1922 	_aio_exec( p );
1923 
1924 #if SYSV_SHM
1925 	/* FIXME: Till vmspace inherit is fixed: */
1926 	if (!vfexec && p->vm_shm) {
1927 		shmexec(p);
1928 	}
1929 #endif
1930 #if SYSV_SEM
1931 	/* Clean up the semaphores */
1932 	semexit(p);
1933 #endif
1934 
1935 	/*
1936 	 * Remember file name for accounting.
1937 	 */
1938 	p->p_acflag &= ~AFORK;
1939 
1940 	set_proc_name(imgp, p);
1941 
1942 #if CONFIG_SECLUDED_MEMORY
1943 	if (secluded_for_apps &&
1944 	    load_result.platform_binary) {
1945 		if (strncmp(p->p_name,
1946 		    "Camera",
1947 		    sizeof(p->p_name)) == 0) {
1948 			task_set_could_use_secluded_mem(task, TRUE);
1949 		} else {
1950 			task_set_could_use_secluded_mem(task, FALSE);
1951 		}
1952 		if (strncmp(p->p_name,
1953 		    "mediaserverd",
1954 		    sizeof(p->p_name)) == 0) {
1955 			task_set_could_also_use_secluded_mem(task, TRUE);
1956 		}
1957 	}
1958 #endif /* CONFIG_SECLUDED_MEMORY */
1959 
1960 #if __arm64__
1961 	if (load_result.legacy_footprint) {
1962 		task_set_legacy_footprint(task);
1963 	}
1964 #endif /* __arm64__ */
1965 
1966 	pal_dbg_set_task_name(task);
1967 
1968 #if DEVELOPMENT || DEBUG
1969 	/*
1970 	 * Update the pid an proc name for importance base if any
1971 	 */
1972 	task_importance_update_owner_info(task);
1973 #endif
1974 
1975 	proc_setexecutableuuid(p, &load_result.uuid[0]);
1976 
1977 #if CONFIG_DTRACE
1978 	dtrace_proc_exec(p);
1979 #endif
1980 
1981 	if (kdebug_enable) {
1982 		long args[4] = {};
1983 
1984 		uintptr_t fsid = 0, fileid = 0;
1985 		if (imgp->ip_vattr) {
1986 			uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
1987 			fsid   = (uintptr_t)fsid64;
1988 			fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
1989 			// check for (unexpected) overflow and trace zero in that case
1990 			if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
1991 				fsid = fileid = 0;
1992 			}
1993 		}
1994 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
1995 		    (uintptr_t)thread_tid(thread));
1996 
1997 		extern void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
1998 		kdebug_proc_name_args(p, args);
1999 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
2000 		    args[2], args[3], (uintptr_t)thread_tid(thread));
2001 	}
2002 
2003 
2004 	/*
2005 	 * If posix_spawned with the START_SUSPENDED flag, stop the
2006 	 * process before it runs.
2007 	 */
2008 	if (imgp->ip_px_sa != NULL) {
2009 		psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
2010 		if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
2011 			proc_lock(p);
2012 			p->p_stat = SSTOP;
2013 			proc_unlock(p);
2014 			(void) task_suspend_internal(task);
2015 		}
2016 	}
2017 
2018 	/*
2019 	 * mark as execed
2020 	 */
2021 	OSBitOrAtomic(P_EXEC, &p->p_flag);
2022 	proc_resetregister(p);
2023 	if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
2024 		proc_lock(p);
2025 		p->p_lflag &= ~P_LPPWAIT;
2026 		proc_unlock(p);
2027 		wakeup((caddr_t)p->p_pptr);
2028 	}
2029 
2030 	/*
2031 	 * Set up dext coredumps on kernel panic.
2032 	 * This requires the following:
2033 	 * - dext_panic_coredump=1 boot-arg (enabled by default on DEVELOPMENT, DEBUG and certain Seed builds)
2034 	 * - process must be a driver
2035 	 * - process must have the com.apple.private.enable-coredump-on-panic entitlement, and the
2036 	 *   entitlement has a string value.
2037 	 * - process must have the com.apple.private.enable-coredump-on-panic-seed-privacy-approved
2038 	 *   entitlement (Seed builds only).
2039 	 *
2040 	 * The core dump file name is formatted with the entitlement string value, followed by a hyphen
2041 	 * and the process PID.
2042 	 */
2043 	if (enable_dext_coredumps_on_panic &&
2044 	    (imgp->ip_flags & IMGPF_DRIVER) != 0 &&
2045 	    (userspace_coredump_name = IOVnodeGetEntitlement(imgp->ip_vp,
2046 	    (int64_t)imgp->ip_arch_offset, USERSPACE_COREDUMP_PANIC_ENTITLEMENT)) != NULL) {
2047 		size_t userspace_coredump_name_len = strlen(userspace_coredump_name);
2048 
2049 		char core_name[MACH_CORE_FILEHEADER_NAMELEN];
2050 		/* 16 - NULL char - strlen("-") - maximum of 5 digits for pid */
2051 		snprintf(core_name, MACH_CORE_FILEHEADER_NAMELEN, "%.9s-%d", userspace_coredump_name, proc_getpid(p));
2052 
2053 		kern_register_userspace_coredump(task, core_name);
2054 
2055 		/* Discard the copy of the entitlement */
2056 		kfree_data(userspace_coredump_name, userspace_coredump_name_len + 1);
2057 		userspace_coredump_name = NULL;
2058 	}
2059 
2060 	goto done;
2061 
2062 badtoolate:
2063 	/* Don't allow child process to execute any instructions */
2064 	if (!spawn) {
2065 		{
2066 			assert(exec_failure_reason != OS_REASON_NULL);
2067 			if (bootarg_execfailurereports) {
2068 				set_proc_name(imgp, current_proc());
2069 			}
2070 			psignal_with_reason(current_proc(), SIGKILL, exec_failure_reason);
2071 			exec_failure_reason = OS_REASON_NULL;
2072 
2073 			if (exec) {
2074 				/* Terminate the exec copy task */
2075 				task_terminate_internal(task);
2076 			}
2077 		}
2078 
2079 		/* We can't stop this system call at this point, so just pretend we succeeded */
2080 		error = 0;
2081 	} else {
2082 		os_reason_free(exec_failure_reason);
2083 		exec_failure_reason = OS_REASON_NULL;
2084 	}
2085 
2086 done:
2087 	if (load_result.threadstate) {
2088 		kfree_data(load_result.threadstate, load_result.threadstate_sz);
2089 		load_result.threadstate = NULL;
2090 	}
2091 
2092 bad:
2093 	/* If we hit this, we likely would have leaked an exit reason */
2094 	assert(exec_failure_reason == OS_REASON_NULL);
2095 	return error;
2096 }
2097 
2098 
2099 
2100 
2101 /*
2102  * Our image activator table; this is the table of the image types we are
2103  * capable of loading.  We list them in order of preference to ensure the
2104  * fastest image load speed.
2105  *
2106  * XXX hardcoded, for now; should use linker sets
2107  */
2108 struct execsw {
2109 	int(*const ex_imgact)(struct image_params *);
2110 	const char *ex_name;
2111 }const execsw[] = {
2112 	{ exec_mach_imgact, "Mach-o Binary" },
2113 	{ exec_fat_imgact, "Fat Binary" },
2114 	{ exec_shell_imgact, "Interpreter Script" },
2115 	{ NULL, NULL}
2116 };
2117 
2118 
2119 /*
2120  * exec_activate_image
2121  *
2122  * Description:	Iterate through the available image activators, and activate
2123  *		the image associated with the imgp structure.  We start with
2124  *		the activator for Mach-o binaries followed by that for Fat binaries
2125  *		for Interpreter scripts.
2126  *
2127  * Parameters:	struct image_params *	Image parameter block
2128  *
2129  * Returns:	0			Success
2130  *		ENOEXEC			No activator for image.
2131  *		EBADEXEC		The executable is corrupt/unknown
2132  *	execargs_alloc:EINVAL		Invalid argument
2133  *	execargs_alloc:EACCES		Permission denied
2134  *	execargs_alloc:EINTR		Interrupted function
2135  *	execargs_alloc:ENOMEM		Not enough space
2136  *	exec_save_path:EFAULT		Bad address
2137  *	exec_save_path:ENAMETOOLONG	Filename too long
2138  *	exec_check_permissions:EACCES	Permission denied
2139  *	exec_check_permissions:ENOEXEC	Executable file format error
2140  *	exec_check_permissions:ETXTBSY	Text file busy [misuse of error code]
2141  *	exec_check_permissions:???
2142  *	namei:???
2143  *	vn_rdwr:???			[anything vn_rdwr can return]
2144  *	<ex_imgact>:???			[anything an imgact can return]
2145  *	EDEADLK				Process is being terminated
2146  */
2147 static int
exec_activate_image(struct image_params * imgp)2148 exec_activate_image(struct image_params *imgp)
2149 {
2150 	struct nameidata *ndp = NULL;
2151 	const char *excpath;
2152 	int error;
2153 	int resid;
2154 	int once = 1;   /* save SGUID-ness for interpreted files */
2155 	int i;
2156 	int itercount = 0;
2157 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2158 
2159 	/*
2160 	 * For exec, the translock needs to be taken on old proc and not
2161 	 * on new shadow proc.
2162 	 */
2163 	if (imgp->ip_flags & IMGPF_EXEC) {
2164 		p = current_proc();
2165 	}
2166 
2167 	error = execargs_alloc(imgp);
2168 	if (error) {
2169 		goto bad_notrans;
2170 	}
2171 
2172 	error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
2173 	if (error) {
2174 		goto bad_notrans;
2175 	}
2176 
2177 	/* Use excpath, which contains the copyin-ed exec path */
2178 	DTRACE_PROC1(exec, uintptr_t, excpath);
2179 
2180 	ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2181 
2182 	NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
2183 	    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2184 
2185 again:
2186 	error = namei(ndp);
2187 	if (error) {
2188 		if (error == ERESTART) {
2189 			error = EINTR;
2190 		}
2191 		goto bad_notrans;
2192 	}
2193 	imgp->ip_ndp = ndp;     /* successful namei(); call nameidone() later */
2194 	imgp->ip_vp = ndp->ni_vp;       /* if set, need to vnode_put() at some point */
2195 
2196 	/*
2197 	 * Before we start the transition from binary A to binary B, make
2198 	 * sure another thread hasn't started exiting the process.  We grab
2199 	 * the proc lock to check p_lflag initially, and the transition
2200 	 * mechanism ensures that the value doesn't change after we release
2201 	 * the lock.
2202 	 */
2203 	proc_lock(p);
2204 	if (p->p_lflag & P_LEXIT) {
2205 		error = EDEADLK;
2206 		proc_unlock(p);
2207 		goto bad_notrans;
2208 	}
2209 	error = proc_transstart(p, 1, 0);
2210 	proc_unlock(p);
2211 	if (error) {
2212 		goto bad_notrans;
2213 	}
2214 
2215 	error = exec_check_permissions(imgp);
2216 	if (error) {
2217 		goto bad;
2218 	}
2219 
2220 	/* Copy; avoid invocation of an interpreter overwriting the original */
2221 	if (once) {
2222 		once = 0;
2223 		*imgp->ip_origvattr = *imgp->ip_vattr;
2224 	}
2225 
2226 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
2227 	    UIO_SYSSPACE, IO_NODELOCKED,
2228 	    vfs_context_ucred(imgp->ip_vfs_context),
2229 	    &resid, vfs_context_proc(imgp->ip_vfs_context));
2230 	if (error) {
2231 		goto bad;
2232 	}
2233 
2234 	if (resid) {
2235 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
2236 	}
2237 
2238 encapsulated_binary:
2239 	/* Limit the number of iterations we will attempt on each binary */
2240 	if (++itercount > EAI_ITERLIMIT) {
2241 		error = EBADEXEC;
2242 		goto bad;
2243 	}
2244 	error = -1;
2245 	for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
2246 		error = (*execsw[i].ex_imgact)(imgp);
2247 
2248 		switch (error) {
2249 		/* case -1: not claimed: continue */
2250 		case -2:                /* Encapsulated binary, imgp->ip_XXX set for next iteration */
2251 			goto encapsulated_binary;
2252 
2253 		case -3:                /* Interpreter */
2254 #if CONFIG_MACF
2255 			/*
2256 			 * Copy the script label for later use. Note that
2257 			 * the label can be different when the script is
2258 			 * actually read by the interpreter.
2259 			 */
2260 			if (imgp->ip_scriptlabelp) {
2261 				mac_vnode_label_free(imgp->ip_scriptlabelp);
2262 				imgp->ip_scriptlabelp = NULL;
2263 			}
2264 			imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
2265 			if (imgp->ip_scriptlabelp == NULL) {
2266 				error = ENOMEM;
2267 				break;
2268 			}
2269 			mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
2270 			    imgp->ip_scriptlabelp);
2271 
2272 			/*
2273 			 * Take a ref of the script vnode for later use.
2274 			 */
2275 			if (imgp->ip_scriptvp) {
2276 				vnode_put(imgp->ip_scriptvp);
2277 				imgp->ip_scriptvp = NULLVP;
2278 			}
2279 			if (vnode_getwithref(imgp->ip_vp) == 0) {
2280 				imgp->ip_scriptvp = imgp->ip_vp;
2281 			}
2282 #endif
2283 
2284 			nameidone(ndp);
2285 
2286 			vnode_put(imgp->ip_vp);
2287 			imgp->ip_vp = NULL;     /* already put */
2288 			imgp->ip_ndp = NULL; /* already nameidone */
2289 
2290 			/* Use excpath, which exec_shell_imgact reset to the interpreter */
2291 			NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
2292 			    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2293 
2294 			proc_transend(p, 0);
2295 			goto again;
2296 
2297 		default:
2298 			break;
2299 		}
2300 	}
2301 
2302 	if (error == -1) {
2303 		error = ENOEXEC;
2304 	} else if (error == 0) {
2305 		if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
2306 			AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
2307 		}
2308 
2309 		/*
2310 		 * Call out to allow 3rd party notification of exec.
2311 		 * Ignore result of kauth_authorize_fileop call.
2312 		 */
2313 		if (kauth_authorize_fileop_has_listeners()) {
2314 			kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
2315 			    KAUTH_FILEOP_EXEC,
2316 			    (uintptr_t)ndp->ni_vp, 0);
2317 		}
2318 	}
2319 bad:
2320 	proc_transend(p, 0);
2321 
2322 bad_notrans:
2323 	if (imgp->ip_strings) {
2324 		execargs_free(imgp);
2325 	}
2326 	if (imgp->ip_ndp) {
2327 		nameidone(imgp->ip_ndp);
2328 	}
2329 	kfree_type(struct nameidata, ndp);
2330 
2331 	return error;
2332 }
2333 
2334 /*
2335  * exec_validate_spawnattr_policy
2336  *
2337  * Description: Validates the entitlements required to set the apptype.
2338  *
2339  * Parameters:  int psa_apptype         posix spawn attribute apptype
2340  *
2341  * Returns:     0                       Success
2342  *              EPERM                   Failure
2343  */
2344 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)2345 exec_validate_spawnattr_policy(int psa_apptype)
2346 {
2347 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2348 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2349 		if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
2350 			if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
2351 				return EPERM;
2352 			}
2353 		}
2354 	}
2355 
2356 	return 0;
2357 }
2358 
2359 /*
2360  * exec_handle_spawnattr_policy
2361  *
2362  * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
2363  *
2364  * Parameters:  proc_t p                process to apply attributes to
2365  *              int psa_apptype         posix spawn attribute apptype
2366  *
2367  * Returns:     0                       Success
2368  */
2369 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)2370 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2371     task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2372 {
2373 	int apptype     = TASK_APPTYPE_NONE;
2374 	int qos_clamp   = THREAD_QOS_UNSPECIFIED;
2375 	task_role_t role = TASK_UNSPECIFIED;
2376 
2377 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2378 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2379 
2380 		switch (proctype) {
2381 		case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2382 			apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2383 			break;
2384 		case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2385 			apptype = TASK_APPTYPE_DAEMON_STANDARD;
2386 			break;
2387 		case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2388 			apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2389 			break;
2390 		case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2391 			apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2392 			break;
2393 		case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2394 			apptype = TASK_APPTYPE_APP_DEFAULT;
2395 			break;
2396 		case POSIX_SPAWN_PROC_TYPE_DRIVER:
2397 			apptype = TASK_APPTYPE_DRIVER;
2398 			break;
2399 		default:
2400 			apptype = TASK_APPTYPE_NONE;
2401 			/* TODO: Should an invalid value here fail the spawn? */
2402 			break;
2403 		}
2404 	}
2405 
2406 	if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2407 		switch (psa_qos_clamp) {
2408 		case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2409 			qos_clamp = THREAD_QOS_UTILITY;
2410 			break;
2411 		case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2412 			qos_clamp = THREAD_QOS_BACKGROUND;
2413 			break;
2414 		case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2415 			qos_clamp = THREAD_QOS_MAINTENANCE;
2416 			break;
2417 		default:
2418 			qos_clamp = THREAD_QOS_UNSPECIFIED;
2419 			/* TODO: Should an invalid value here fail the spawn? */
2420 			break;
2421 		}
2422 	}
2423 
2424 	if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2425 		proc_darwin_role_to_task_role(psa_darwin_role, &role);
2426 	}
2427 
2428 	if (apptype != TASK_APPTYPE_NONE ||
2429 	    qos_clamp != THREAD_QOS_UNSPECIFIED ||
2430 	    role != TASK_UNSPECIFIED ||
2431 	    port_actions->portwatch_count) {
2432 		proc_set_task_spawnpolicy(proc_task(p), thread, apptype, qos_clamp, role,
2433 		    port_actions->portwatch_array, port_actions->portwatch_count);
2434 	}
2435 
2436 	if (port_actions->registered_count) {
2437 		if (mach_ports_register(proc_task(p), port_actions->registered_array,
2438 		    port_actions->registered_count)) {
2439 			return EINVAL;
2440 		}
2441 		/* mach_ports_register() consumed the array */
2442 		port_actions->registered_array = NULL;
2443 		port_actions->registered_count = 0;
2444 	}
2445 
2446 	return 0;
2447 }
2448 
2449 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2450 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2451 {
2452 	if (port_actions->excport_array) {
2453 		for (uint32_t i = 0; i < port_actions->exception_port_count; i++) {
2454 			ipc_port_t port = NULL;
2455 			if ((port = port_actions->excport_array[i].port) != NULL) {
2456 				ipc_port_release_send(port);
2457 			}
2458 		}
2459 		kfree_type(struct exception_port_action_t, port_actions->exception_port_count,
2460 		    port_actions->excport_array);
2461 	}
2462 
2463 	if (port_actions->portwatch_array) {
2464 		for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2465 			ipc_port_t port = NULL;
2466 			if ((port = port_actions->portwatch_array[i]) != NULL) {
2467 				ipc_port_release_send(port);
2468 			}
2469 		}
2470 		kfree_type(ipc_port_t, port_actions->portwatch_count,
2471 		    port_actions->portwatch_array);
2472 	}
2473 
2474 	if (port_actions->registered_array) {
2475 		for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2476 			ipc_port_t port = NULL;
2477 			if ((port = port_actions->registered_array[i]) != NULL) {
2478 				ipc_port_release_send(port);
2479 			}
2480 		}
2481 		kfree_type(ipc_port_t, port_actions->registered_count,
2482 		    port_actions->registered_array);
2483 	}
2484 }
2485 
2486 /*
2487  * exec_handle_port_actions
2488  *
2489  * Description:	Go through the _posix_port_actions_t contents,
2490  *              calling task_set_special_port, task_set_exception_ports
2491  *              and/or audit_session_spawnjoin for the current task.
2492  *
2493  * Parameters:	struct image_params *	Image parameter block
2494  *
2495  * Returns:	0			Success
2496  *              EINVAL			Failure
2497  *              ENOTSUP			Illegal posix_spawn attr flag was set
2498  */
2499 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2500 exec_handle_port_actions(struct image_params *imgp,
2501     struct exec_port_actions *actions)
2502 {
2503 	_posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2504 #if CONFIG_AUDIT
2505 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2506 #endif
2507 	_ps_port_action_t *act = NULL;
2508 	task_t task = get_threadtask(imgp->ip_new_thread);
2509 	ipc_port_t port = NULL;
2510 	errno_t ret = 0;
2511 	int i = 0, portwatch_i = 0, registered_i = 0, excport_i = 0;
2512 	kern_return_t kr;
2513 	boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2514 	boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2515 	int ptrauth_task_port_count = 0;
2516 
2517 	for (i = 0; i < pacts->pspa_count; i++) {
2518 		act = &pacts->pspa_actions[i];
2519 
2520 		switch (act->port_type) {
2521 		case PSPA_SPECIAL:
2522 #if CONFIG_AUDIT
2523 		case PSPA_AU_SESSION:
2524 #endif
2525 			break;
2526 		case PSPA_EXCEPTION:
2527 			if (++actions->exception_port_count > TASK_MAX_EXCEPTION_PORT_COUNT) {
2528 				ret = EINVAL;
2529 				goto done;
2530 			}
2531 			break;
2532 		case PSPA_IMP_WATCHPORTS:
2533 			if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
2534 				ret = EINVAL;
2535 				goto done;
2536 			}
2537 			break;
2538 		case PSPA_REGISTERED_PORTS:
2539 			if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
2540 				ret = EINVAL;
2541 				goto done;
2542 			}
2543 			break;
2544 		case PSPA_PTRAUTH_TASK_PORT:
2545 			if (++ptrauth_task_port_count > 1) {
2546 				ret = EINVAL;
2547 				goto done;
2548 			}
2549 			break;
2550 		default:
2551 			ret = EINVAL;
2552 			goto done;
2553 		}
2554 	}
2555 
2556 	if (actions->exception_port_count) {
2557 		actions->excport_array = kalloc_type(struct exception_port_action_t,
2558 		    actions->exception_port_count, Z_WAITOK | Z_ZERO);
2559 
2560 		if (actions->excport_array == NULL) {
2561 			ret = ENOMEM;
2562 			goto done;
2563 		}
2564 	}
2565 	if (actions->portwatch_count) {
2566 		if (in_exec && task_has_watchport_boost) {
2567 			ret = EINVAL;
2568 			goto done;
2569 		}
2570 		actions->portwatch_array = kalloc_type(ipc_port_t,
2571 		    actions->portwatch_count, Z_WAITOK | Z_ZERO);
2572 		if (actions->portwatch_array == NULL) {
2573 			ret = ENOMEM;
2574 			goto done;
2575 		}
2576 	}
2577 
2578 	if (actions->registered_count) {
2579 		actions->registered_array = kalloc_type(ipc_port_t,
2580 		    actions->registered_count, Z_WAITOK | Z_ZERO);
2581 		if (actions->registered_array == NULL) {
2582 			ret = ENOMEM;
2583 			goto done;
2584 		}
2585 	}
2586 
2587 	for (i = 0; i < pacts->pspa_count; i++) {
2588 		act = &pacts->pspa_actions[i];
2589 
2590 		if (MACH_PORT_VALID(act->new_port)) {
2591 			kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2592 			    act->new_port, MACH_MSG_TYPE_COPY_SEND,
2593 			    (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2594 
2595 			if (kr != KERN_SUCCESS) {
2596 				ret = EINVAL;
2597 				goto done;
2598 			}
2599 		} else {
2600 			/* it's NULL or DEAD */
2601 			port = CAST_MACH_NAME_TO_PORT(act->new_port);
2602 		}
2603 
2604 		switch (act->port_type) {
2605 		case PSPA_SPECIAL:
2606 			kr = task_set_special_port(task, act->which, port);
2607 
2608 			if (kr != KERN_SUCCESS) {
2609 				ret = EINVAL;
2610 			}
2611 			break;
2612 
2613 #if CONFIG_AUDIT
2614 		case PSPA_AU_SESSION:
2615 			ret = audit_session_spawnjoin(p, port);
2616 			if (ret) {
2617 				/* audit_session_spawnjoin() has already dropped the reference in case of error. */
2618 				goto done;
2619 			}
2620 
2621 			break;
2622 #endif
2623 		case PSPA_EXCEPTION:
2624 			assert(excport_i < actions->exception_port_count);
2625 			/* hold on to this till end of spawn */
2626 			actions->excport_array[excport_i].port_action = act;
2627 			actions->excport_array[excport_i].port = port;
2628 			excport_i++;
2629 			break;
2630 		case PSPA_IMP_WATCHPORTS:
2631 			assert(portwatch_i < actions->portwatch_count);
2632 			/* hold on to this till end of spawn */
2633 			actions->portwatch_array[portwatch_i++] = port;
2634 			break;
2635 		case PSPA_REGISTERED_PORTS:
2636 			assert(registered_i < actions->registered_count);
2637 			/* hold on to this till end of spawn */
2638 			actions->registered_array[registered_i++] = port;
2639 			break;
2640 
2641 		case PSPA_PTRAUTH_TASK_PORT:
2642 			/* No one uses this, this is no longer supported, just a no-op */
2643 			ipc_port_release_send(port);
2644 			break;
2645 		default:
2646 			ret = EINVAL;
2647 			break;
2648 		}
2649 
2650 		if (ret) {
2651 			/* action failed, so release port resources */
2652 			ipc_port_release_send(port);
2653 			break;
2654 		}
2655 	}
2656 
2657 done:
2658 	if (0 != ret) {
2659 		DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2660 	}
2661 	return ret;
2662 }
2663 
2664 
2665 /*
2666  * exec_handle_exception_port_actions
2667  *
2668  * Description:	Go through the saved exception ports in exec_port_actions,
2669  *              calling task_set_exception_ports for the current Task.
2670  *              This must happen after image activation, and after exec_resettextvp()
2671  *				because task_set_exception_ports checks the `TF_PLATFORM` bit and entitlements.
2672  *
2673  * Parameters:	struct image_params *		Image parameter block
2674  *                              struct exec_port_actions *  Saved Port Actions
2675  *
2676  * Returns:	0			Success
2677  *              EINVAL			task_set_exception_ports failed
2678  */
2679 static errno_t
exec_handle_exception_port_actions(const struct image_params * imgp,const struct exec_port_actions * actions)2680 exec_handle_exception_port_actions(const struct image_params *imgp,
2681     const struct exec_port_actions *actions)
2682 {
2683 	task_t task = get_threadtask(imgp->ip_new_thread);
2684 
2685 	for (int i = 0; i < actions->exception_port_count; i++) {
2686 		ipc_port_t port = actions->excport_array[i].port;
2687 		_ps_port_action_t *act = actions->excport_array[i].port_action;
2688 		assert(act != NULL);
2689 		kern_return_t kr = task_set_exception_ports(task, act->mask, port,
2690 		    act->behavior, act->flavor);
2691 		if (kr != KERN_SUCCESS) {
2692 			DTRACE_PROC1(spawn__exception__port__failure, mach_port_name_t, act->new_port);
2693 			return EINVAL;
2694 		}
2695 		actions->excport_array[i].port = NULL;
2696 	}
2697 
2698 	return 0;
2699 }
2700 
2701 
2702 /*
2703  * exec_handle_file_actions
2704  *
2705  * Description:	Go through the _posix_file_actions_t contents applying the
2706  *		open, close, and dup2 operations to the open file table for
2707  *		the current process.
2708  *
2709  * Parameters:	struct image_params *	Image parameter block
2710  *
2711  * Returns:	0			Success
2712  *		???
2713  *
2714  * Note:	Actions are applied in the order specified, with the credential
2715  *		of the parent process.  This is done to permit the parent
2716  *		process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
2717  *		the child following operations the child may in fact not be
2718  *		normally permitted to perform.
2719  */
2720 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)2721 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
2722 {
2723 	int error = 0;
2724 	int action;
2725 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2726 	_posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
2727 	int ival[2];            /* dummy retval for system calls) */
2728 #if CONFIG_AUDIT
2729 	struct uthread *uthread = current_uthread();
2730 #endif
2731 
2732 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
2733 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2734 
2735 		switch (psfa->psfaa_type) {
2736 		case PSFA_OPEN: {
2737 			/*
2738 			 * Open is different, in that it requires the use of
2739 			 * a path argument, which is normally copied in from
2740 			 * user space; because of this, we have to support an
2741 			 * open from kernel space that passes an address space
2742 			 * context of UIO_SYSSPACE, and casts the address
2743 			 * argument to a user_addr_t.
2744 			 */
2745 			struct vnode_attr *vap;
2746 			struct nameidata *ndp;
2747 			int mode = psfa->psfaa_openargs.psfao_mode;
2748 			int origfd;
2749 			struct {
2750 				struct vnode_attr va;
2751 				struct nameidata nd;
2752 			} *__open_data;
2753 
2754 			__open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
2755 			if (__open_data == NULL) {
2756 				error = ENOMEM;
2757 				break;
2758 			}
2759 
2760 			vap = &__open_data->va;
2761 			ndp = &__open_data->nd;
2762 
2763 			VATTR_INIT(vap);
2764 			/* Mask off all but regular access permissions */
2765 			mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
2766 			VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
2767 
2768 			AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
2769 
2770 			NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2771 			    CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
2772 			    imgp->ip_vfs_context);
2773 
2774 			error = open1(imgp->ip_vfs_context, ndp,
2775 			    psfa->psfaa_openargs.psfao_oflag,
2776 			    vap, NULL, NULL, &origfd, AUTH_OPEN_NOAUTHFD);
2777 
2778 			kfree_type(typeof(*__open_data), __open_data);
2779 
2780 			AUDIT_SUBCALL_EXIT(uthread, error);
2781 
2782 			/*
2783 			 * If there's an error, or we get the right fd by
2784 			 * accident, then drop out here.  This is easier than
2785 			 * reworking all the open code to preallocate fd
2786 			 * slots, and internally taking one as an argument.
2787 			 */
2788 			if (error || origfd == psfa->psfaa_filedes) {
2789 				break;
2790 			}
2791 
2792 			/*
2793 			 * If we didn't fall out from an error, we ended up
2794 			 * with the wrong fd; so now we've got to try to dup2
2795 			 * it to the right one.
2796 			 */
2797 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2798 			error = dup2(p, origfd, psfa->psfaa_filedes, ival);
2799 			AUDIT_SUBCALL_EXIT(uthread, error);
2800 			if (error) {
2801 				break;
2802 			}
2803 
2804 			/*
2805 			 * Finally, close the original fd.
2806 			 */
2807 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2808 			error = close_nocancel(p, origfd);
2809 			AUDIT_SUBCALL_EXIT(uthread, error);
2810 		}
2811 		break;
2812 
2813 		case PSFA_DUP2: {
2814 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2815 			error = dup2(p, psfa->psfaa_filedes,
2816 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2817 			AUDIT_SUBCALL_EXIT(uthread, error);
2818 		}
2819 		break;
2820 
2821 		case PSFA_FILEPORT_DUP2: {
2822 			ipc_port_t port;
2823 			kern_return_t kr;
2824 			int origfd;
2825 
2826 			if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
2827 				error = EINVAL;
2828 				break;
2829 			}
2830 
2831 			kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2832 			    psfa->psfaa_fileport, MACH_MSG_TYPE_COPY_SEND,
2833 			    (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2834 
2835 			if (kr != KERN_SUCCESS) {
2836 				error = EINVAL;
2837 				break;
2838 			}
2839 
2840 			error = fileport_makefd(p, port, 0, &origfd);
2841 
2842 			if (IPC_PORT_NULL != port) {
2843 				ipc_port_release_send(port);
2844 			}
2845 
2846 			if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
2847 				break;
2848 			}
2849 
2850 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2851 			error = dup2(p, origfd,
2852 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2853 			AUDIT_SUBCALL_EXIT(uthread, error);
2854 			if (error) {
2855 				break;
2856 			}
2857 
2858 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2859 			error = close_nocancel(p, origfd);
2860 			AUDIT_SUBCALL_EXIT(uthread, error);
2861 		}
2862 		break;
2863 
2864 		case PSFA_CLOSE: {
2865 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2866 			error = close_nocancel(p, psfa->psfaa_filedes);
2867 			AUDIT_SUBCALL_EXIT(uthread, error);
2868 		}
2869 		break;
2870 
2871 		case PSFA_INHERIT: {
2872 			struct fileproc *fp;
2873 
2874 			/*
2875 			 * Check to see if the descriptor exists, and
2876 			 * ensure it's -not- marked as close-on-exec.
2877 			 *
2878 			 * Attempting to "inherit" a guarded fd will
2879 			 * result in a error.
2880 			 */
2881 
2882 			proc_fdlock(p);
2883 			if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
2884 				error = EBADF;
2885 			} else if (fp->fp_guard_attrs) {
2886 				error = fp_guard_exception(p, psfa->psfaa_filedes,
2887 				    fp, kGUARD_EXC_NOCLOEXEC);
2888 			} else {
2889 				fp->fp_flags &= ~FP_CLOEXEC;
2890 				error = 0;
2891 			}
2892 			proc_fdunlock(p);
2893 		}
2894 		break;
2895 
2896 		case PSFA_CHDIR: {
2897 			/*
2898 			 * Chdir is different, in that it requires the use of
2899 			 * a path argument, which is normally copied in from
2900 			 * user space; because of this, we have to support a
2901 			 * chdir from kernel space that passes an address space
2902 			 * context of UIO_SYSSPACE, and casts the address
2903 			 * argument to a user_addr_t.
2904 			 */
2905 			struct nameidata *nd;
2906 			nd = kalloc_type(struct nameidata,
2907 			    Z_WAITOK | Z_ZERO | Z_NOFAIL);
2908 
2909 			AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
2910 			NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2911 			    CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
2912 			    imgp->ip_vfs_context);
2913 
2914 			error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
2915 			kfree_type(struct nameidata, nd);
2916 			AUDIT_SUBCALL_EXIT(uthread, error);
2917 		}
2918 		break;
2919 
2920 		case PSFA_FCHDIR: {
2921 			struct fchdir_args fchdira;
2922 
2923 			fchdira.fd = psfa->psfaa_filedes;
2924 
2925 			AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
2926 			error = fchdir(p, &fchdira, ival);
2927 			AUDIT_SUBCALL_EXIT(uthread, error);
2928 		}
2929 		break;
2930 
2931 		default:
2932 			error = EINVAL;
2933 			break;
2934 		}
2935 
2936 		/* All file actions failures are considered fatal, per POSIX */
2937 
2938 		if (error) {
2939 			if (PSFA_OPEN == psfa->psfaa_type) {
2940 				DTRACE_PROC1(spawn__open__failure, uintptr_t,
2941 				    psfa->psfaa_openargs.psfao_path);
2942 			} else {
2943 				DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
2944 			}
2945 			break;
2946 		}
2947 	}
2948 
2949 	if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
2950 		return error;
2951 	}
2952 
2953 	/*
2954 	 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
2955 	 * this spawn only) as if "close on exec" is the default
2956 	 * disposition of all pre-existing file descriptors.  In this case,
2957 	 * the list of file descriptors mentioned in the file actions
2958 	 * are the only ones that can be inherited, so mark them now.
2959 	 *
2960 	 * The actual closing part comes later, in fdt_exec().
2961 	 */
2962 	proc_fdlock(p);
2963 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
2964 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2965 		int fd = psfa->psfaa_filedes;
2966 
2967 		switch (psfa->psfaa_type) {
2968 		case PSFA_DUP2:
2969 		case PSFA_FILEPORT_DUP2:
2970 			fd = psfa->psfaa_dup2args.psfad_newfiledes;
2971 			OS_FALLTHROUGH;
2972 		case PSFA_OPEN:
2973 		case PSFA_INHERIT:
2974 			*fdflags(p, fd) |= UF_INHERIT;
2975 			break;
2976 
2977 		case PSFA_CLOSE:
2978 		case PSFA_CHDIR:
2979 		case PSFA_FCHDIR:
2980 			/*
2981 			 * Although PSFA_FCHDIR does have a file descriptor, it is not
2982 			 * *creating* one, thus we do not automatically mark it for
2983 			 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
2984 			 * wishes it to be inherited should use the PSFA_INHERIT action
2985 			 * explicitly.
2986 			 */
2987 			break;
2988 		}
2989 	}
2990 	proc_fdunlock(p);
2991 
2992 	return 0;
2993 }
2994 
2995 #if CONFIG_MACF
2996 /*
2997  * Check that the extension's data is within the bounds of the
2998  * allocation storing all extensions' data
2999  */
3000 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)3001 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
3002     const _ps_mac_policy_extension_t *ext)
3003 {
3004 	uint64_t dataend;
3005 
3006 	if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
3007 		return EOVERFLOW;
3008 	}
3009 	if (__improbable(dataend > px_s->datalen)) {
3010 		return EINVAL;
3011 	}
3012 
3013 	return 0;
3014 }
3015 
3016 /*
3017  * exec_spawnattr_getmacpolicyinfo
3018  */
3019 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)3020 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
3021 {
3022 	const struct ip_px_smpx_s *px_s = macextensions;
3023 	const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
3024 	int i;
3025 
3026 	if (px_s == NULL) {
3027 		return NULL;
3028 	}
3029 
3030 	psmx = px_s->array;
3031 	if (psmx == NULL) {
3032 		return NULL;
3033 	}
3034 
3035 	for (i = 0; i < psmx->psmx_count; i++) {
3036 		const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3037 		if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
3038 			if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
3039 				panic("invalid mac policy extension data");
3040 			}
3041 			if (lenp != NULL) {
3042 				*lenp = (size_t)extension->datalen;
3043 			}
3044 			return (void *)((uintptr_t)px_s->data + extension->dataoff);
3045 		}
3046 	}
3047 
3048 	if (lenp != NULL) {
3049 		*lenp = 0;
3050 	}
3051 	return NULL;
3052 }
3053 
3054 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)3055 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
3056     struct ip_px_smpx_s *pxsp)
3057 {
3058 	_posix_spawn_mac_policy_extensions_t psmx = NULL;
3059 	uint8_t *data = NULL;
3060 	uint64_t datalen = 0;
3061 	uint64_t dataoff = 0;
3062 	int error = 0;
3063 
3064 	bzero(pxsp, sizeof(*pxsp));
3065 
3066 	if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
3067 	    px_args->mac_extensions_size > PAGE_SIZE) {
3068 		error = EINVAL;
3069 		goto bad;
3070 	}
3071 
3072 	psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
3073 	if (psmx == NULL) {
3074 		error = ENOMEM;
3075 		goto bad;
3076 	}
3077 
3078 	error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
3079 	if (error) {
3080 		goto bad;
3081 	}
3082 
3083 	size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
3084 	if (extsize == 0 || extsize > px_args->mac_extensions_size) {
3085 		error = EINVAL;
3086 		goto bad;
3087 	}
3088 
3089 	for (int i = 0; i < psmx->psmx_count; i++) {
3090 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3091 		if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
3092 			error = EINVAL;
3093 			goto bad;
3094 		}
3095 		if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
3096 			error = ENOMEM;
3097 			goto bad;
3098 		}
3099 	}
3100 
3101 	data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
3102 	if (data == NULL) {
3103 		error = ENOMEM;
3104 		goto bad;
3105 	}
3106 
3107 	for (int i = 0; i < psmx->psmx_count; i++) {
3108 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3109 
3110 #if !__LP64__
3111 		if (extension->data > UINT32_MAX) {
3112 			goto bad;
3113 		}
3114 #endif
3115 		error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
3116 		if (error) {
3117 			error = ENOMEM;
3118 			goto bad;
3119 		}
3120 		extension->dataoff = dataoff;
3121 		dataoff += extension->datalen;
3122 	}
3123 
3124 	pxsp->array = psmx;
3125 	pxsp->data = data;
3126 	pxsp->datalen = datalen;
3127 	return 0;
3128 
3129 bad:
3130 	kfree_data(psmx, px_args->mac_extensions_size);
3131 	kfree_data(data, (vm_size_t)datalen);
3132 	return error;
3133 }
3134 #endif /* CONFIG_MACF */
3135 
3136 #if CONFIG_COALITIONS
3137 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])3138 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
3139 {
3140 	for (int c = 0; c < COALITION_NUM_TYPES; c++) {
3141 		if (coal[c]) {
3142 			coalition_remove_active(coal[c]);
3143 			coalition_release(coal[c]);
3144 		}
3145 	}
3146 }
3147 #endif
3148 
3149 #if CONFIG_PERSONAS
3150 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)3151 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
3152 {
3153 	int error = 0;
3154 	struct persona *persona = NULL;
3155 
3156 	if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
3157 		return EPERM;
3158 	}
3159 
3160 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3161 		if (px_persona->pspi_ngroups > NGROUPS_MAX) {
3162 			return EINVAL;
3163 		}
3164 	}
3165 
3166 	persona = persona_lookup(px_persona->pspi_id);
3167 	if (!persona) {
3168 		error = ESRCH;
3169 		goto out;
3170 	}
3171 
3172 out:
3173 	if (persona) {
3174 		persona_put(persona);
3175 	}
3176 
3177 	return error;
3178 }
3179 
3180 static bool
kauth_cred_model_setpersona(kauth_cred_t model,struct _posix_spawn_persona_info * px_persona)3181 kauth_cred_model_setpersona(
3182 	kauth_cred_t            model,
3183 	struct _posix_spawn_persona_info *px_persona)
3184 {
3185 	bool updated = false;
3186 
3187 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
3188 		updated |= kauth_cred_model_setresuid(model,
3189 		    px_persona->pspi_uid,
3190 		    px_persona->pspi_uid,
3191 		    px_persona->pspi_uid,
3192 		    KAUTH_UID_NONE);
3193 	}
3194 
3195 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
3196 		updated |= kauth_cred_model_setresgid(model,
3197 		    px_persona->pspi_gid,
3198 		    px_persona->pspi_gid,
3199 		    px_persona->pspi_gid);
3200 	}
3201 
3202 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3203 		updated |= kauth_cred_model_setgroups(model,
3204 		    px_persona->pspi_groups,
3205 		    px_persona->pspi_ngroups,
3206 		    px_persona->pspi_gmuid);
3207 	}
3208 
3209 	return updated;
3210 }
3211 
3212 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)3213 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
3214 {
3215 	struct persona *persona = NULL;
3216 
3217 	/*
3218 	 * we want to spawn into the given persona, but we want to override
3219 	 * the kauth with a different UID/GID combo
3220 	 */
3221 	persona = persona_lookup(px_persona->pspi_id);
3222 	if (!persona) {
3223 		return ESRCH;
3224 	}
3225 
3226 	return persona_proc_adopt(p, persona,
3227 	           ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
3228 		return kauth_cred_model_setpersona(model, px_persona);
3229 	});
3230 }
3231 #endif
3232 
3233 #if __arm64__
3234 #if DEVELOPMENT || DEBUG
3235 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
3236     LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
3237 
3238 __startup_func
3239 static void
legacy_footprint_entitlement_mode_init(void)3240 legacy_footprint_entitlement_mode_init(void)
3241 {
3242 	/*
3243 	 * legacy_footprint_entitlement_mode specifies the behavior we want associated
3244 	 * with the entitlement. The supported modes are:
3245 	 *
3246 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3247 	 *	Indicates that we want every process to have the memory accounting
3248 	 *	that is available in iOS 12.0 and beyond.
3249 	 *
3250 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3251 	 *	Indicates that for every process that has the 'legacy footprint entitlement',
3252 	 *      we want to give it the old iOS 11.0 accounting behavior which accounted some
3253 	 *	of the process's memory to the kernel.
3254 	 *
3255 	 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3256 	 *      Indicates that for every process that has the 'legacy footprint entitlement',
3257 	 *	we want it to have a higher memory limit which will help them acclimate to the
3258 	 *	iOS 12.0 (& beyond) accounting behavior that does the right accounting.
3259 	 *      The bonus added to the system-wide task limit to calculate this higher memory limit
3260 	 *      is available in legacy_footprint_bonus_mb.
3261 	 */
3262 
3263 	if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
3264 	    legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
3265 		legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
3266 	}
3267 }
3268 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
3269 #else
3270 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
3271 #endif
3272 
3273 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)3274 proc_legacy_footprint_entitled(proc_t p, task_t task)
3275 {
3276 #pragma unused(p)
3277 	boolean_t legacy_footprint_entitled;
3278 
3279 	switch (legacy_footprint_entitlement_mode) {
3280 	case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3281 		/* the entitlement is ignored */
3282 		break;
3283 	case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3284 		/* the entitlement grants iOS11 legacy accounting */
3285 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3286 		if (legacy_footprint_entitled) {
3287 			task_set_legacy_footprint(task);
3288 		}
3289 		break;
3290 	case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3291 		/* the entitlement grants a footprint limit increase */
3292 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3293 		if (legacy_footprint_entitled) {
3294 			task_set_extra_footprint_limit(task);
3295 		}
3296 		break;
3297 	default:
3298 		break;
3299 	}
3300 }
3301 
3302 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)3303 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
3304 {
3305 #pragma unused(p)
3306 	boolean_t ios13extended_footprint_entitled;
3307 
3308 	/* the entitlement grants a footprint limit increase */
3309 	ios13extended_footprint_entitled = memorystatus_task_has_ios13extended_footprint_limit(proc_task(p));
3310 	if (ios13extended_footprint_entitled) {
3311 		task_set_ios13extended_footprint_limit(task);
3312 	}
3313 }
3314 
3315 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)3316 proc_increased_memory_limit_entitled(proc_t p, task_t task)
3317 {
3318 	bool entitled = memorystatus_task_has_increased_memory_limit_entitlement(task);
3319 
3320 	if (entitled) {
3321 		memorystatus_act_on_entitled_task_limit(p);
3322 	}
3323 }
3324 
3325 /*
3326  * Check for any of the various entitlements that permit a higher
3327  * task footprint limit or alternate accounting and apply them.
3328  */
3329 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)3330 proc_footprint_entitlement_hacks(proc_t p, task_t task)
3331 {
3332 	proc_legacy_footprint_entitled(p, task);
3333 	proc_ios13extended_footprint_entitled(p, task);
3334 	proc_increased_memory_limit_entitled(p, task);
3335 }
3336 #endif /* __arm64__ */
3337 
3338 /*
3339  * Processes with certain entitlements are granted a jumbo-size VM map.
3340  */
3341 static inline void
proc_apply_jit_and_vm_policies(struct image_params * imgp,proc_t p,task_t task)3342 proc_apply_jit_and_vm_policies(struct image_params *imgp, proc_t p, task_t task)
3343 {
3344 #if CONFIG_MACF
3345 	bool jit_entitled = false;
3346 #endif /* CONFIG_MACF */
3347 	bool needs_jumbo_va = false;
3348 	struct _posix_spawnattr *psa = imgp->ip_px_sa;
3349 
3350 #if CONFIG_MACF
3351 	jit_entitled = (mac_proc_check_map_anon(p, 0, 0, 0, MAP_JIT, NULL) == 0);
3352 	needs_jumbo_va = jit_entitled || IOTaskHasEntitlement(task,
3353 	    "com.apple.developer.kernel.extended-virtual-addressing") ||
3354 	    memorystatus_task_has_increased_memory_limit_entitlement(task);
3355 #else
3356 #pragma unused(p)
3357 #endif /* CONFIG_MACF */
3358 
3359 	if (needs_jumbo_va) {
3360 		vm_map_set_jumbo(get_task_map(task));
3361 	}
3362 
3363 	if (psa && psa->psa_max_addr) {
3364 		vm_map_set_max_addr(get_task_map(task), psa->psa_max_addr);
3365 	}
3366 
3367 #if CONFIG_MAP_RANGES
3368 	if (task_get_platform_binary(task) && !proc_is_simulated(p)) {
3369 		/*
3370 		 * This must be done last as it needs to observe
3371 		 * any kind of VA space growth that was requested
3372 		 */
3373 		vm_map_range_configure(get_task_map(task));
3374 	}
3375 #endif /* CONFIG_MAP_RANGES */
3376 
3377 #if CONFIG_MACF
3378 	if (jit_entitled) {
3379 		vm_map_set_jit_entitled(get_task_map(task));
3380 
3381 	}
3382 #endif /* CONFIG_MACF */
3383 
3384 	if (task_get_platform_binary(task)) {
3385 		/*
3386 		 * Pre-emptively disable TPRO remapping for
3387 		 * platform binaries
3388 		 */
3389 		vm_map_set_tpro_enforcement(get_task_map(task));
3390 	}
3391 }
3392 
3393 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)3394 spawn_posix_cred_adopt(proc_t p,
3395     struct _posix_spawn_posix_cred_info *px_pcred_info)
3396 {
3397 	int error = 0;
3398 
3399 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3400 		struct setgid_args args = {
3401 			.gid = px_pcred_info->pspci_gid,
3402 		};
3403 		error = setgid(p, &args, NULL);
3404 		if (error) {
3405 			return error;
3406 		}
3407 	}
3408 
3409 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3410 		error = setgroups_internal(p,
3411 		    px_pcred_info->pspci_ngroups,
3412 		    px_pcred_info->pspci_groups,
3413 		    px_pcred_info->pspci_gmuid);
3414 		if (error) {
3415 			return error;
3416 		}
3417 	}
3418 
3419 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3420 		struct setuid_args args = {
3421 			.uid = px_pcred_info->pspci_uid,
3422 		};
3423 		error = setuid(p, &args, NULL);
3424 		if (error) {
3425 			return error;
3426 		}
3427 	}
3428 	return 0;
3429 }
3430 
3431 /*
3432  * posix_spawn
3433  *
3434  * Parameters:	uap->pid		Pointer to pid return area
3435  *		uap->fname		File name to exec
3436  *		uap->argp		Argument list
3437  *		uap->envp		Environment list
3438  *
3439  * Returns:	0			Success
3440  *		EINVAL			Invalid argument
3441  *		ENOTSUP			Not supported
3442  *		ENOEXEC			Executable file format error
3443  *	exec_activate_image:EINVAL	Invalid argument
3444  *	exec_activate_image:EACCES	Permission denied
3445  *	exec_activate_image:EINTR	Interrupted function
3446  *	exec_activate_image:ENOMEM	Not enough space
3447  *	exec_activate_image:EFAULT	Bad address
3448  *	exec_activate_image:ENAMETOOLONG	Filename too long
3449  *	exec_activate_image:ENOEXEC	Executable file format error
3450  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
3451  *	exec_activate_image:EAUTH	Image decryption failed
3452  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
3453  *	exec_activate_image:???
3454  *	mac_execve_enter:???
3455  *
3456  * TODO:	Expect to need __mac_posix_spawn() at some point...
3457  *		Handle posix_spawnattr_t
3458  *		Handle posix_spawn_file_actions_t
3459  */
3460 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3461 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3462 {
3463 	proc_t p = ap;
3464 	user_addr_t pid = uap->pid;
3465 	int ival[2];            /* dummy retval for setpgid() */
3466 	char *subsystem_root_path = NULL;
3467 	struct image_params *imgp = NULL;
3468 	struct vnode_attr *vap = NULL;
3469 	struct vnode_attr *origvap = NULL;
3470 	struct uthread  *uthread = 0;   /* compiler complains if not set to 0*/
3471 	int error, sig;
3472 	int is_64 = IS_64BIT_PROCESS(p);
3473 	struct vfs_context context;
3474 	struct user__posix_spawn_args_desc px_args = {};
3475 	struct _posix_spawnattr px_sa = {};
3476 	_posix_spawn_file_actions_t px_sfap = NULL;
3477 	_posix_spawn_port_actions_t px_spap = NULL;
3478 	struct __kern_sigaction vec;
3479 	boolean_t spawn_no_exec = FALSE;
3480 	boolean_t proc_transit_set = TRUE;
3481 	boolean_t proc_signal_set = TRUE;
3482 	boolean_t exec_done = FALSE;
3483 	os_reason_t exec_failure_reason = NULL;
3484 
3485 	struct exec_port_actions port_actions = { };
3486 	vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3487 	task_t old_task = current_task();
3488 	task_t new_task = NULL;
3489 	boolean_t should_release_proc_ref = FALSE;
3490 	void *inherit = NULL;
3491 	uint8_t crash_behavior = 0;
3492 	uint64_t crash_behavior_deadline = 0;
3493 #if CONFIG_PERSONAS
3494 	struct _posix_spawn_persona_info *px_persona = NULL;
3495 #endif
3496 	struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3497 	struct {
3498 		struct image_params imgp;
3499 		struct vnode_attr va;
3500 		struct vnode_attr origva;
3501 	} *__spawn_data;
3502 
3503 	/*
3504 	 * Allocate a big chunk for locals instead of using stack since these
3505 	 * structures are pretty big.
3506 	 */
3507 	__spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3508 	if (__spawn_data == NULL) {
3509 		error = ENOMEM;
3510 		goto bad;
3511 	}
3512 	imgp = &__spawn_data->imgp;
3513 	vap = &__spawn_data->va;
3514 	origvap = &__spawn_data->origva;
3515 
3516 	/* Initialize the common data in the image_params structure */
3517 	imgp->ip_user_fname = uap->path;
3518 	imgp->ip_user_argv = uap->argv;
3519 	imgp->ip_user_envv = uap->envp;
3520 	imgp->ip_vattr = vap;
3521 	imgp->ip_origvattr = origvap;
3522 	imgp->ip_vfs_context = &context;
3523 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3524 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3525 	imgp->ip_mac_return = 0;
3526 	imgp->ip_px_persona = NULL;
3527 	imgp->ip_px_pcred_info = NULL;
3528 	imgp->ip_cs_error = OS_REASON_NULL;
3529 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3530 	imgp->ip_subsystem_root_path = NULL;
3531 	imgp->ip_inherited_shared_region_id = NULL;
3532 	imgp->ip_inherited_jop_pid = 0;
3533 	uthread_set_exec_data(current_uthread(), imgp);
3534 
3535 	if (uap->adesc != USER_ADDR_NULL) {
3536 		if (is_64) {
3537 			error = copyin(uap->adesc, &px_args, sizeof(px_args));
3538 		} else {
3539 			struct user32__posix_spawn_args_desc px_args32;
3540 
3541 			error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3542 
3543 			/*
3544 			 * Convert arguments descriptor from external 32 bit
3545 			 * representation to internal 64 bit representation
3546 			 */
3547 			px_args.attr_size = px_args32.attr_size;
3548 			px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3549 			px_args.file_actions_size = px_args32.file_actions_size;
3550 			px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3551 			px_args.port_actions_size = px_args32.port_actions_size;
3552 			px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3553 			px_args.mac_extensions_size = px_args32.mac_extensions_size;
3554 			px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3555 			px_args.coal_info_size = px_args32.coal_info_size;
3556 			px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3557 			px_args.persona_info_size = px_args32.persona_info_size;
3558 			px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3559 			px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3560 			px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3561 			px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3562 			px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3563 			px_args.conclave_id_size = px_args32.conclave_id_size;
3564 			px_args.conclave_id = CAST_USER_ADDR_T(px_args32.conclave_id);
3565 		}
3566 		if (error) {
3567 			goto bad;
3568 		}
3569 
3570 		if (px_args.attr_size != 0) {
3571 			/*
3572 			 * We are not copying the port_actions pointer,
3573 			 * because we already have it from px_args.
3574 			 * This is a bit fragile: <rdar://problem/16427422>
3575 			 */
3576 
3577 			if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3578 				goto bad;
3579 			}
3580 
3581 			imgp->ip_px_sa = &px_sa;
3582 		}
3583 		if (px_args.file_actions_size != 0) {
3584 			/* Limit file_actions to allowed number of open files */
3585 			size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3586 
3587 			if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3588 			    maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3589 				error = EINVAL;
3590 				goto bad;
3591 			}
3592 
3593 			px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3594 			if (px_sfap == NULL) {
3595 				error = ENOMEM;
3596 				goto bad;
3597 			}
3598 			imgp->ip_px_sfa = px_sfap;
3599 
3600 			if ((error = copyin(px_args.file_actions, px_sfap,
3601 			    px_args.file_actions_size)) != 0) {
3602 				goto bad;
3603 			}
3604 
3605 			/* Verify that the action count matches the struct size */
3606 			size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3607 			if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3608 				error = EINVAL;
3609 				goto bad;
3610 			}
3611 		}
3612 		if (px_args.port_actions_size != 0) {
3613 			/* Limit port_actions to one page of data */
3614 			if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3615 			    px_args.port_actions_size > PAGE_SIZE) {
3616 				error = EINVAL;
3617 				goto bad;
3618 			}
3619 
3620 			px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3621 			if (px_spap == NULL) {
3622 				error = ENOMEM;
3623 				goto bad;
3624 			}
3625 			imgp->ip_px_spa = px_spap;
3626 
3627 			if ((error = copyin(px_args.port_actions, px_spap,
3628 			    px_args.port_actions_size)) != 0) {
3629 				goto bad;
3630 			}
3631 
3632 			/* Verify that the action count matches the struct size */
3633 			size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3634 			if (pasize == 0 || pasize != px_args.port_actions_size) {
3635 				error = EINVAL;
3636 				goto bad;
3637 			}
3638 		}
3639 #if CONFIG_PERSONAS
3640 		/* copy in the persona info */
3641 		if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3642 			/* for now, we need the exact same struct in user space */
3643 			if (px_args.persona_info_size != sizeof(*px_persona)) {
3644 				error = ERANGE;
3645 				goto bad;
3646 			}
3647 
3648 			px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3649 			if (px_persona == NULL) {
3650 				error = ENOMEM;
3651 				goto bad;
3652 			}
3653 			imgp->ip_px_persona = px_persona;
3654 
3655 			if ((error = copyin(px_args.persona_info, px_persona,
3656 			    px_args.persona_info_size)) != 0) {
3657 				goto bad;
3658 			}
3659 			if ((error = spawn_validate_persona(px_persona)) != 0) {
3660 				goto bad;
3661 			}
3662 		}
3663 #endif
3664 		/* copy in the posix cred info */
3665 		if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
3666 			/* for now, we need the exact same struct in user space */
3667 			if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
3668 				error = ERANGE;
3669 				goto bad;
3670 			}
3671 
3672 			if (!kauth_cred_issuser(kauth_cred_get())) {
3673 				error = EPERM;
3674 				goto bad;
3675 			}
3676 
3677 			px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
3678 			if (px_pcred_info == NULL) {
3679 				error = ENOMEM;
3680 				goto bad;
3681 			}
3682 			imgp->ip_px_pcred_info = px_pcred_info;
3683 
3684 			if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
3685 			    px_args.posix_cred_info_size)) != 0) {
3686 				goto bad;
3687 			}
3688 
3689 			if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3690 				if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
3691 					error = EINVAL;
3692 					goto bad;
3693 				}
3694 			}
3695 		}
3696 #if CONFIG_MACF
3697 		if (px_args.mac_extensions_size != 0) {
3698 			if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
3699 				goto bad;
3700 			}
3701 		}
3702 #endif /* CONFIG_MACF */
3703 		if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
3704 			/*
3705 			 * If a valid-looking subsystem root has been
3706 			 * specified...
3707 			 */
3708 			if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
3709 				/*
3710 				 * ...AND the parent has the entitlement, copy
3711 				 * the subsystem root path in.
3712 				 */
3713 				subsystem_root_path = zalloc_flags(ZV_NAMEI,
3714 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3715 
3716 				if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
3717 					goto bad;
3718 				}
3719 
3720 				/* Paranoia */
3721 				subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
3722 			}
3723 		}
3724 	}
3725 
3726 	if (IOTaskHasEntitlement(old_task, SPAWN_SET_PANIC_CRASH_BEHAVIOR)) {
3727 		/* Truncate to uint8_t since we only support 2 flags for now */
3728 		crash_behavior = (uint8_t)px_sa.psa_crash_behavior;
3729 		crash_behavior_deadline = px_sa.psa_crash_behavior_deadline;
3730 	}
3731 
3732 	/* set uthread to parent */
3733 	uthread = current_uthread();
3734 
3735 	/*
3736 	 * <rdar://6640530>; this does not result in a behaviour change
3737 	 * relative to Leopard, so there should not be any existing code
3738 	 * which depends on it.
3739 	 */
3740 
3741 	if (imgp->ip_px_sa != NULL) {
3742 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
3743 		if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
3744 			imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
3745 		}
3746 #if (DEVELOPMENT || DEBUG)
3747 		if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
3748 			imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
3749 		}
3750 #endif
3751 
3752 		if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
3753 			goto bad;
3754 		}
3755 	}
3756 
3757 	/*
3758 	 * If we don't have the extension flag that turns "posix_spawn()"
3759 	 * into "execve() with options", then we will be creating a new
3760 	 * process which does not inherit memory from the parent process,
3761 	 * which is one of the most expensive things about using fork()
3762 	 * and execve().
3763 	 */
3764 	if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3765 		/* Set the new task's coalition, if it is requested.  */
3766 		coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
3767 #if CONFIG_COALITIONS
3768 		int i, ncoals;
3769 		kern_return_t kr = KERN_SUCCESS;
3770 		struct _posix_spawn_coalition_info coal_info;
3771 		int coal_role[COALITION_NUM_TYPES];
3772 
3773 		if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
3774 			goto do_fork1;
3775 		}
3776 
3777 		memset(&coal_info, 0, sizeof(coal_info));
3778 
3779 		if (px_args.coal_info_size > sizeof(coal_info)) {
3780 			px_args.coal_info_size = sizeof(coal_info);
3781 		}
3782 		error = copyin(px_args.coal_info,
3783 		    &coal_info, px_args.coal_info_size);
3784 		if (error != 0) {
3785 			goto bad;
3786 		}
3787 
3788 		ncoals = 0;
3789 		for (i = 0; i < COALITION_NUM_TYPES; i++) {
3790 			uint64_t cid = coal_info.psci_info[i].psci_id;
3791 			if (cid != 0) {
3792 				/*
3793 				 * don't allow tasks which are not in a
3794 				 * privileged coalition to spawn processes
3795 				 * into coalitions other than their own
3796 				 */
3797 				if (!task_is_in_privileged_coalition(proc_task(p), i) &&
3798 				    !IOTaskHasEntitlement(proc_task(p), COALITION_SPAWN_ENTITLEMENT)) {
3799 					coal_dbg("ERROR: %d not in privilegd "
3800 					    "coalition of type %d",
3801 					    proc_getpid(p), i);
3802 					spawn_coalitions_release_all(coal);
3803 					error = EPERM;
3804 					goto bad;
3805 				}
3806 
3807 				coal_dbg("searching for coalition id:%llu", cid);
3808 				/*
3809 				 * take a reference and activation on the
3810 				 * coalition to guard against free-while-spawn
3811 				 * races
3812 				 */
3813 				coal[i] = coalition_find_and_activate_by_id(cid);
3814 				if (coal[i] == COALITION_NULL) {
3815 					coal_dbg("could not find coalition id:%llu "
3816 					    "(perhaps it has been terminated or reaped)", cid);
3817 					/*
3818 					 * release any other coalition's we
3819 					 * may have a reference to
3820 					 */
3821 					spawn_coalitions_release_all(coal);
3822 					error = ESRCH;
3823 					goto bad;
3824 				}
3825 				if (coalition_type(coal[i]) != i) {
3826 					coal_dbg("coalition with id:%lld is not of type:%d"
3827 					    " (it's type:%d)", cid, i, coalition_type(coal[i]));
3828 					spawn_coalitions_release_all(coal);
3829 					error = ESRCH;
3830 					goto bad;
3831 				}
3832 				coal_role[i] = coal_info.psci_info[i].psci_role;
3833 				ncoals++;
3834 			}
3835 		}
3836 		if (ncoals < COALITION_NUM_TYPES) {
3837 			/*
3838 			 * If the user is attempting to spawn into a subset of
3839 			 * the known coalition types, then make sure they have
3840 			 * _at_least_ specified a resource coalition. If not,
3841 			 * the following fork1() call will implicitly force an
3842 			 * inheritance from 'p' and won't actually spawn the
3843 			 * new task into the coalitions the user specified.
3844 			 * (also the call to coalitions_set_roles will panic)
3845 			 */
3846 			if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
3847 				spawn_coalitions_release_all(coal);
3848 				error = EINVAL;
3849 				goto bad;
3850 			}
3851 		}
3852 do_fork1:
3853 #endif /* CONFIG_COALITIONS */
3854 
3855 		/*
3856 		 * note that this will implicitly inherit the
3857 		 * caller's persona (if it exists)
3858 		 */
3859 		error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
3860 		/* returns a thread and task reference */
3861 
3862 		if (error == 0) {
3863 			new_task = get_threadtask(imgp->ip_new_thread);
3864 		}
3865 #if CONFIG_COALITIONS
3866 		/* set the roles of this task within each given coalition */
3867 		if (error == 0) {
3868 			kr = coalitions_set_roles(coal, new_task, coal_role);
3869 			if (kr != KERN_SUCCESS) {
3870 				error = EINVAL;
3871 			}
3872 			if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
3873 			    MACH_COALITION_ADOPT))) {
3874 				for (i = 0; i < COALITION_NUM_TYPES; i++) {
3875 					if (coal[i] != COALITION_NULL) {
3876 						/*
3877 						 * On 32-bit targets, uniqueid
3878 						 * will get truncated to 32 bits
3879 						 */
3880 						KDBG_RELEASE(MACHDBG_CODE(
3881 							    DBG_MACH_COALITION,
3882 							    MACH_COALITION_ADOPT),
3883 						    coalition_id(coal[i]),
3884 						    get_task_uniqueid(new_task));
3885 					}
3886 				}
3887 			}
3888 		}
3889 
3890 		/* drop our references and activations - fork1() now holds them */
3891 		spawn_coalitions_release_all(coal);
3892 #endif /* CONFIG_COALITIONS */
3893 		if (error != 0) {
3894 			goto bad;
3895 		}
3896 		imgp->ip_flags |= IMGPF_SPAWN;  /* spawn w/o exec */
3897 		spawn_no_exec = TRUE;           /* used in later tests */
3898 	} else {
3899 		/* Adjust the user proc count */
3900 		(void)chgproccnt(kauth_getruid(), 1);
3901 		/*
3902 		 * For execve case, create a new proc, task and thread
3903 		 * but don't make the proc visible to userland. After
3904 		 * image activation, the new proc would take place of
3905 		 * the old proc in pid hash and other lists that make
3906 		 * the proc visible to the system.
3907 		 */
3908 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_FLAGS_FOR_EXEC);
3909 
3910 		/* task and thread ref returned by cloneproc */
3911 		if (imgp->ip_new_thread == NULL) {
3912 			(void)chgproccnt(kauth_getruid(), -1);
3913 			error = ENOMEM;
3914 			goto bad;
3915 		}
3916 
3917 		new_task = get_threadtask(imgp->ip_new_thread);
3918 		imgp->ip_flags |= IMGPF_EXEC;
3919 	}
3920 
3921 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
3922 
3923 	if (spawn_no_exec) {
3924 		/*
3925 		 * We had to wait until this point before firing the
3926 		 * proc:::create probe, otherwise p would not point to the
3927 		 * child process.
3928 		 */
3929 		DTRACE_PROC1(create, proc_t, p);
3930 	}
3931 	assert(p != NULL);
3932 
3933 	if (subsystem_root_path) {
3934 		/* If a subsystem root was specified, swap it in */
3935 		char * old_subsystem_root_path = p->p_subsystem_root_path;
3936 		p->p_subsystem_root_path = subsystem_root_path;
3937 		subsystem_root_path = old_subsystem_root_path;
3938 	}
3939 
3940 	p->p_crash_behavior = crash_behavior;
3941 	p->p_crash_behavior_deadline = crash_behavior_deadline;
3942 
3943 	p->p_crash_count = px_sa.psa_crash_count;
3944 	p->p_throttle_timeout = px_sa.psa_throttle_timeout;
3945 
3946 	/* We'll need the subsystem root for setting up Apple strings */
3947 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
3948 
3949 	context.vc_thread = imgp->ip_new_thread;
3950 	context.vc_ucred = proc_ucred_unsafe(p);  /* in init */
3951 
3952 	/*
3953 	 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
3954 	 * to handle the file_actions.
3955 	 */
3956 
3957 	/* Has spawn file actions? */
3958 	if (imgp->ip_px_sfa != NULL) {
3959 		/*
3960 		 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
3961 		 * is handled in exec_handle_file_actions().
3962 		 */
3963 #if CONFIG_AUDIT
3964 		/*
3965 		 * The file actions auditing can overwrite the upath of
3966 		 * AUE_POSIX_SPAWN audit record.  Save the audit record.
3967 		 */
3968 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
3969 		uthread->uu_ar = NULL;
3970 #endif
3971 		error = exec_handle_file_actions(imgp,
3972 		    imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
3973 #if CONFIG_AUDIT
3974 		/* Restore the AUE_POSIX_SPAWN audit record. */
3975 		uthread->uu_ar = save_uu_ar;
3976 #endif
3977 		if (error != 0) {
3978 			goto bad;
3979 		}
3980 	}
3981 
3982 	/* Has spawn port actions? */
3983 	if (imgp->ip_px_spa != NULL) {
3984 #if CONFIG_AUDIT
3985 		/*
3986 		 * Do the same for the port actions as we did for the file
3987 		 * actions.  Save the AUE_POSIX_SPAWN audit record.
3988 		 */
3989 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
3990 		uthread->uu_ar = NULL;
3991 #endif
3992 		error = exec_handle_port_actions(imgp, &port_actions);
3993 #if CONFIG_AUDIT
3994 		/* Restore the AUE_POSIX_SPAWN audit record. */
3995 		uthread->uu_ar = save_uu_ar;
3996 #endif
3997 		if (error != 0) {
3998 			goto bad;
3999 		}
4000 	}
4001 
4002 	/* Has spawn attr? */
4003 	if (imgp->ip_px_sa != NULL) {
4004 		/*
4005 		 * Reset UID/GID to parent's RUID/RGID; This works only
4006 		 * because the operation occurs before the call
4007 		 * to exec_handle_sugid() by the image activator called
4008 		 * from exec_activate_image().
4009 		 *
4010 		 * POSIX requires that any setuid/setgid bits on the process
4011 		 * image will take precedence over the spawn attributes
4012 		 * (re)setting them.
4013 		 *
4014 		 * Modifications to p_ucred must be guarded using the
4015 		 * proc's ucred lock. This prevents others from accessing
4016 		 * a garbage credential.
4017 		 */
4018 		if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
4019 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
4020 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model){
4021 				return kauth_cred_model_setuidgid(model,
4022 				kauth_cred_getruid(parent),
4023 				kauth_cred_getrgid(parent));
4024 			});
4025 		}
4026 
4027 		if (imgp->ip_px_pcred_info) {
4028 			if (!spawn_no_exec) {
4029 				error = ENOTSUP;
4030 				goto bad;
4031 			}
4032 
4033 			error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
4034 			if (error != 0) {
4035 				goto bad;
4036 			}
4037 		}
4038 
4039 #if CONFIG_PERSONAS
4040 		if (imgp->ip_px_persona != NULL) {
4041 			if (!spawn_no_exec) {
4042 				error = ENOTSUP;
4043 				goto bad;
4044 			}
4045 
4046 			/*
4047 			 * If we were asked to spawn a process into a new persona,
4048 			 * do the credential switch now (which may override the UID/GID
4049 			 * inherit done just above). It's important to do this switch
4050 			 * before image activation both for reasons stated above, and
4051 			 * to ensure that the new persona has access to the image/file
4052 			 * being executed.
4053 			 */
4054 			error = spawn_persona_adopt(p, imgp->ip_px_persona);
4055 			if (error != 0) {
4056 				goto bad;
4057 			}
4058 		}
4059 #endif /* CONFIG_PERSONAS */
4060 #if !SECURE_KERNEL
4061 		/*
4062 		 * Disable ASLR for the spawned process.
4063 		 *
4064 		 * But only do so if we are not embedded + RELEASE.
4065 		 * While embedded allows for a boot-arg (-disable_aslr)
4066 		 * to deal with this (which itself is only honored on
4067 		 * DEVELOPMENT or DEBUG builds of xnu), it is often
4068 		 * useful or necessary to disable ASLR on a per-process
4069 		 * basis for unit testing and debugging.
4070 		 */
4071 		if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
4072 			OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
4073 		}
4074 #endif /* !SECURE_KERNEL */
4075 
4076 		/* Randomize high bits of ASLR slide */
4077 		if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
4078 			imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
4079 		}
4080 
4081 #if !SECURE_KERNEL
4082 		/*
4083 		 * Forcibly disallow execution from data pages for the spawned process
4084 		 * even if it would otherwise be permitted by the architecture default.
4085 		 */
4086 		if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
4087 			imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
4088 		}
4089 #endif /* !SECURE_KERNEL */
4090 
4091 #if     __has_feature(ptrauth_calls)
4092 		if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
4093 			imgp->ip_flags |= IMGPF_RESLIDE;
4094 		}
4095 #endif /* __has_feature(ptrauth_calls) */
4096 
4097 		if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
4098 		    POSIX_SPAWN_PROC_TYPE_DRIVER) {
4099 			imgp->ip_flags |= IMGPF_DRIVER;
4100 		}
4101 	}
4102 
4103 	/*
4104 	 * Disable ASLR during image activation.  This occurs either if the
4105 	 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
4106 	 * P_DISABLE_ASLR was inherited from the parent process.
4107 	 */
4108 	if (p->p_flag & P_DISABLE_ASLR) {
4109 		imgp->ip_flags |= IMGPF_DISABLE_ASLR;
4110 	}
4111 
4112 	/*
4113 	 * Clear transition flag so we won't hang if exec_activate_image() causes
4114 	 * an automount (and launchd does a proc sysctl to service it).
4115 	 *
4116 	 * <rdar://problem/6848672>, <rdar://problem/5959568>.
4117 	 */
4118 	proc_transend(p, 0);
4119 	proc_transit_set = 0;
4120 
4121 	if (!spawn_no_exec) {
4122 		/*
4123 		 * Clear the signal lock in case of exec, since
4124 		 * image activation uses psignal on child process.
4125 		 */
4126 		proc_signalend(p, 0);
4127 		proc_signal_set = 0;
4128 	}
4129 
4130 #if MAC_SPAWN   /* XXX */
4131 	if (uap->mac_p != USER_ADDR_NULL) {
4132 		error = mac_execve_enter(uap->mac_p, imgp);
4133 		if (error) {
4134 			goto bad;
4135 		}
4136 	}
4137 #endif
4138 
4139 	/*
4140 	 * Activate the image.
4141 	 * Warning: If activation failed after point of no return, it returns error
4142 	 * as 0 and pretends the call succeeded.
4143 	 */
4144 	error = exec_activate_image(imgp);
4145 #if defined(HAS_APPLE_PAC)
4146 	ml_task_set_jop_pid_from_shared_region(new_task);
4147 	ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
4148 	ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
4149 	ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4150 #endif
4151 
4152 
4153 	/*
4154 	 * If you've come here to add support for some new HW feature or some per-process or per-vmmap
4155 	 * or per-pmap flag that needs to be set before the process runs, or are in general lost, here
4156 	 * is some help. This summary was accurate as of Jul 2022. Use git log as needed. This comment
4157 	 * is here to prevent a recurrence of rdar://96307913
4158 	 *
4159 	 * In posix_spawn, following is what happens:
4160 	 * 1. Lots of prep and checking work
4161 	 * 2. Image activation via exec_activate_image(). The new task will get a new pmap here
4162 	 * 3. More prep work. (YOU ARE HERE)
4163 	 * 4. exec_resettextvp() is called
4164 	 * 5. At this point it is safe to check entitlements and code signatures
4165 	 * 6. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4166 	 *    The new thread is allowed to run in kernel. It cannot yet get to userland
4167 	 * 7. More things done here. This is your chance to affect the task before it runs in
4168 	 *    userspace
4169 	 * 8. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4170 	 *     The new thread is allowed to run in userland
4171 	 */
4172 
4173 	if (error == 0 && !spawn_no_exec) {
4174 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp->ip_new_thread, &inherit);
4175 		/* proc ref returned */
4176 		should_release_proc_ref = TRUE;
4177 	}
4178 
4179 	if (error == 0) {
4180 		/* process completed the exec, but may have failed after point of no return */
4181 		exec_done = TRUE;
4182 		/*
4183 		 * Enable new task IPC access if exec_activate_image() returned an
4184 		 * active task. (Checks active bit in ipc_task_enable() under lock).
4185 		 */
4186 		ipc_task_enable(new_task);
4187 	}
4188 
4189 
4190 	if (!error && imgp->ip_px_sa != NULL) {
4191 		thread_t child_thread = imgp->ip_new_thread;
4192 		uthread_t child_uthread = get_bsdthread_info(child_thread);
4193 
4194 		/*
4195 		 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
4196 		 * activation, else when image activation fails (before the point of no
4197 		 * return) would leave the parent process in a modified state.
4198 		 */
4199 		if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
4200 			struct setpgid_args spga;
4201 			spga.pid = proc_getpid(p);
4202 			spga.pgid = px_sa.psa_pgroup;
4203 			/*
4204 			 * Effectively, call setpgid() system call; works
4205 			 * because there are no pointer arguments.
4206 			 */
4207 			if ((error = setpgid(p, &spga, ival)) != 0) {
4208 				goto bad_px_sa;
4209 			}
4210 		}
4211 
4212 		if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
4213 			error = setsid_internal(p);
4214 			if (error != 0) {
4215 				goto bad_px_sa;
4216 			}
4217 		}
4218 
4219 		/*
4220 		 * If we have a spawn attr, and it contains signal related flags,
4221 		 * the we need to process them in the "context" of the new child
4222 		 * process, so we have to process it following image activation,
4223 		 * prior to making the thread runnable in user space.  This is
4224 		 * necessitated by some signal information being per-thread rather
4225 		 * than per-process, and we don't have the new allocation in hand
4226 		 * until after the image is activated.
4227 		 */
4228 
4229 		/*
4230 		 * Mask a list of signals, instead of them being unmasked, if
4231 		 * they were unmasked in the parent; note that some signals
4232 		 * are not maskable.
4233 		 */
4234 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
4235 			child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
4236 		}
4237 		/*
4238 		 * Default a list of signals instead of ignoring them, if
4239 		 * they were ignored in the parent.  Note that we pass
4240 		 * spawn_no_exec to setsigvec() to indicate that we called
4241 		 * fork1() and therefore do not need to call proc_signalstart()
4242 		 * internally.
4243 		 */
4244 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
4245 			vec.sa_handler = SIG_DFL;
4246 			vec.sa_tramp = 0;
4247 			vec.sa_mask = 0;
4248 			vec.sa_flags = 0;
4249 			for (sig = 1; sig < NSIG; sig++) {
4250 				if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
4251 					error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
4252 				}
4253 			}
4254 		}
4255 
4256 		/*
4257 		 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
4258 		 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
4259 		 * limit.
4260 		 *
4261 		 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
4262 		 */
4263 		if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
4264 			/*
4265 			 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
4266 			 * an entitlement to configure the monitor a certain way seems silly, since
4267 			 * whomever is turning it on could just as easily choose not to do so.
4268 			 */
4269 			error = proc_set_task_ruse_cpu(proc_task(p),
4270 			    TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
4271 			    (uint8_t)px_sa.psa_cpumonitor_percent,
4272 			    px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
4273 			    0, TRUE);
4274 		}
4275 
4276 
4277 		if (px_pcred_info &&
4278 		    (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
4279 			/*
4280 			 * setlogin() must happen after setsid()
4281 			 */
4282 			setlogin_internal(p, px_pcred_info->pspci_login);
4283 		}
4284 
4285 bad_px_sa:
4286 		if (error != 0) {
4287 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
4288 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR, 0, 0);
4289 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR);
4290 		}
4291 	}
4292 
4293 bad:
4294 
4295 	if (error == 0) {
4296 		/* reset delay idle sleep status if set */
4297 #if CONFIG_DELAY_IDLE_SLEEP
4298 		if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
4299 			OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
4300 		}
4301 #endif /* CONFIG_DELAY_IDLE_SLEEP */
4302 		/* upon  successful spawn, re/set the proc control state */
4303 		if (imgp->ip_px_sa != NULL) {
4304 			switch (px_sa.psa_pcontrol) {
4305 			case POSIX_SPAWN_PCONTROL_THROTTLE:
4306 				p->p_pcaction = P_PCTHROTTLE;
4307 				break;
4308 			case POSIX_SPAWN_PCONTROL_SUSPEND:
4309 				p->p_pcaction = P_PCSUSP;
4310 				break;
4311 			case POSIX_SPAWN_PCONTROL_KILL:
4312 				p->p_pcaction = P_PCKILL;
4313 				break;
4314 			case POSIX_SPAWN_PCONTROL_NONE:
4315 			default:
4316 				p->p_pcaction = 0;
4317 				break;
4318 			}
4319 			;
4320 		}
4321 		exec_resettextvp(p, imgp);
4322 
4323 		/* Set task exception ports now that we can check entitlements */
4324 		if (imgp->ip_px_spa != NULL) {
4325 			error = exec_handle_exception_port_actions(imgp, &port_actions);
4326 		}
4327 
4328 #if CONFIG_MEMORYSTATUS
4329 		/* Set jetsam priority for DriverKit processes */
4330 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4331 			px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
4332 		}
4333 
4334 		/* Has jetsam attributes? */
4335 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
4336 			/*
4337 			 * With 2-level high-water-mark support, POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no
4338 			 * longer relevant, as background limits are described via the inactive limit slots.
4339 			 *
4340 			 * That said, however, if the POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in,
4341 			 * we attempt to mimic previous behavior by forcing the BG limit data into the
4342 			 * inactive/non-fatal mode and force the active slots to hold system_wide/fatal mode.
4343 			 */
4344 
4345 			if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
4346 				memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
4347 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
4348 				    TRUE,
4349 				    -1, TRUE,
4350 				    px_sa.psa_memlimit_inactive, FALSE);
4351 			} else {
4352 				memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
4353 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
4354 				    TRUE,
4355 				    px_sa.psa_memlimit_active,
4356 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL),
4357 				    px_sa.psa_memlimit_inactive,
4358 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL));
4359 			}
4360 		}
4361 
4362 		/* Has jetsam relaunch behavior? */
4363 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
4364 			/*
4365 			 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
4366 			 * This data would be used by the jetsam subsystem to determine the position and protection
4367 			 * offered to this process on dirty -> clean transitions.
4368 			 */
4369 			int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
4370 			switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
4371 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
4372 				relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
4373 				break;
4374 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
4375 				relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
4376 				break;
4377 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
4378 				relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
4379 				break;
4380 			default:
4381 				break;
4382 			}
4383 			memorystatus_relaunch_flags_update(p, relaunch_flags);
4384 		}
4385 
4386 #endif /* CONFIG_MEMORYSTATUS */
4387 		if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
4388 			task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
4389 		}
4390 
4391 #if CONFIG_PROC_RESOURCE_LIMITS
4392 		if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
4393 			task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
4394 			    (uint32_t)px_sa.psa_port_hard_limit);
4395 		}
4396 
4397 		if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
4398 			proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
4399 			    (int)px_sa.psa_filedesc_hard_limit);
4400 		}
4401 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
4402 
4403 		/* Disable wakeup monitoring for DriverKit processes */
4404 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4405 			uint32_t      flags = WAKEMON_DISABLE;
4406 			task_wakeups_monitor_ctl(new_task, &flags, NULL);
4407 		}
4408 	}
4409 
4410 
4411 	/*
4412 	 * If we successfully called fork1() or cloneproc, we always need
4413 	 * to do this. This is because we come back from that call with
4414 	 * signals blocked in the child, and we have to unblock them, for exec
4415 	 * case they are unblocked before activation, but for true spawn case
4416 	 * we want to wait until after we've performed any spawn actions.
4417 	 * This has to happen before process_signature(), which uses psignal.
4418 	 */
4419 	if (proc_transit_set) {
4420 		proc_transend(p, 0);
4421 	}
4422 
4423 	/*
4424 	 * Drop the signal lock on the child which was taken on our
4425 	 * behalf by forkproc()/cloneproc() to prevent signals being
4426 	 * received by the child in a partially constructed state.
4427 	 */
4428 	if (proc_signal_set) {
4429 		proc_signalend(p, 0);
4430 	}
4431 
4432 	if (error == 0) {
4433 		/*
4434 		 * We need to initialize the bank context behind the protection of
4435 		 * the proc_trans lock to prevent a race with exit. We can't do this during
4436 		 * exec_activate_image because task_bank_init checks entitlements that
4437 		 * aren't loaded until subsequent calls (including exec_resettextvp).
4438 		 */
4439 		error = proc_transstart(p, 0, 0);
4440 
4441 		if (error == 0) {
4442 			task_bank_init(new_task);
4443 			proc_transend(p, 0);
4444 		}
4445 
4446 #if __arm64__
4447 		proc_footprint_entitlement_hacks(p, new_task);
4448 #endif /* __arm64__ */
4449 
4450 #if XNU_TARGET_OS_OSX
4451 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4452 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4453 			vm_map_single_jit(get_task_map(new_task));
4454 		}
4455 #endif /* XNU_TARGET_OS_OSX */
4456 
4457 #if __has_feature(ptrauth_calls)
4458 		task_set_pac_exception_fatal_flag(new_task);
4459 #endif /* __has_feature(ptrauth_calls) */
4460 	}
4461 
4462 	/* Inherit task role from old task to new task for exec */
4463 	if (error == 0 && !spawn_no_exec) {
4464 		proc_inherit_task_role(new_task, old_task);
4465 	}
4466 
4467 #if CONFIG_ARCADE
4468 	if (error == 0) {
4469 		/*
4470 		 * Check to see if we need to trigger an arcade upcall AST now
4471 		 * that the vnode has been reset on the task.
4472 		 */
4473 		arcade_prepare(new_task, imgp->ip_new_thread);
4474 	}
4475 #endif /* CONFIG_ARCADE */
4476 
4477 	if (error == 0) {
4478 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
4479 	}
4480 
4481 	/* Clear the initial wait on the thread before handling spawn policy */
4482 	if (imgp && imgp->ip_new_thread) {
4483 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4484 	}
4485 
4486 	/*
4487 	 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4488 	 * and bind any portwatch ports to the new task.
4489 	 * This must be done after the exec so that the child's thread is ready,
4490 	 * and after the in transit state has been released, because priority is
4491 	 * dropped here so we need to be prepared for a potentially long preemption interval
4492 	 *
4493 	 * TODO: Consider splitting this up into separate phases
4494 	 */
4495 	if (error == 0 && imgp->ip_px_sa != NULL) {
4496 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4497 
4498 		error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4499 		    psa->psa_darwin_role, &port_actions);
4500 	}
4501 
4502 	/* Transfer the turnstile watchport boost to new task if in exec */
4503 	if (error == 0 && !spawn_no_exec) {
4504 		task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4505 	}
4506 
4507 	if (error == 0 && imgp->ip_px_sa != NULL) {
4508 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4509 
4510 		if (psa->psa_no_smt) {
4511 			task_set_no_smt(new_task);
4512 		}
4513 		if (psa->psa_tecs) {
4514 			task_set_tecs(new_task);
4515 		}
4516 	}
4517 
4518 	if (error == 0 && imgp->ip_px_sa != NULL) {
4519 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4520 
4521 		if (psa->psa_options & PSA_OPTION_DATALESS_IOPOLICY) {
4522 			struct _iopol_param_t iop_param = {
4523 				.iop_scope = IOPOL_SCOPE_PROCESS,
4524 				.iop_iotype = IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES,
4525 				.iop_policy = psa->psa_dataless_iopolicy,
4526 			};
4527 			error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_SET, iop_param.iop_scope,
4528 			    iop_param.iop_policy, &iop_param);
4529 		}
4530 	}
4531 
4532 	if (error == 0) {
4533 		/* Apply the main thread qos */
4534 		thread_t main_thread = imgp->ip_new_thread;
4535 		task_set_main_thread_qos(new_task, main_thread);
4536 	}
4537 
4538 	/*
4539 	 * Release any ports we kept around for binding to the new task
4540 	 * We need to release the rights even if the posix_spawn has failed.
4541 	 */
4542 	if (imgp->ip_px_spa != NULL) {
4543 		exec_port_actions_destroy(&port_actions);
4544 	}
4545 
4546 	/*
4547 	 * We have to delay operations which might throw a signal until after
4548 	 * the signals have been unblocked; however, we want that to happen
4549 	 * after exec_resettextvp() so that the textvp is correct when they
4550 	 * fire.
4551 	 */
4552 	if (error == 0) {
4553 		error = process_signature(p, imgp);
4554 
4555 		/*
4556 		 * Pay for our earlier safety; deliver the delayed signals from
4557 		 * the incomplete spawn process now that it's complete.
4558 		 */
4559 		if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4560 			psignal_vfork(p, proc_task(p), imgp->ip_new_thread, SIGTRAP);
4561 		}
4562 
4563 		if (error == 0 && !spawn_no_exec) {
4564 			KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4565 			    proc_getpid(p));
4566 		}
4567 	}
4568 
4569 	if (spawn_no_exec) {
4570 		/* flag the 'fork' has occurred */
4571 		proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4572 	}
4573 
4574 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
4575 	if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4576 		proc_knote(p, NOTE_EXEC);
4577 	}
4578 
4579 	if (imgp != NULL) {
4580 		uthread_set_exec_data(current_uthread(), NULL);
4581 		if (imgp->ip_vp) {
4582 			vnode_put(imgp->ip_vp);
4583 		}
4584 		if (imgp->ip_scriptvp) {
4585 			vnode_put(imgp->ip_scriptvp);
4586 		}
4587 		if (imgp->ip_strings) {
4588 			execargs_free(imgp);
4589 		}
4590 		if (imgp->ip_free_map) {
4591 			/* Free the map after dropping iocount on vnode to avoid deadlock */
4592 			vm_map_deallocate(imgp->ip_free_map);
4593 		}
4594 		kfree_data(imgp->ip_px_sfa,
4595 		    px_args.file_actions_size);
4596 		kfree_data(imgp->ip_px_spa,
4597 		    px_args.port_actions_size);
4598 #if CONFIG_PERSONAS
4599 		kfree_data(imgp->ip_px_persona,
4600 		    px_args.persona_info_size);
4601 #endif
4602 		kfree_data(imgp->ip_px_pcred_info,
4603 		    px_args.posix_cred_info_size);
4604 
4605 		if (subsystem_root_path != NULL) {
4606 			zfree(ZV_NAMEI, subsystem_root_path);
4607 		}
4608 #if CONFIG_MACF
4609 		struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
4610 		kfree_data(px_s->array, px_args.mac_extensions_size);
4611 		kfree_data(px_s->data, (vm_size_t)px_s->datalen);
4612 
4613 		if (imgp->ip_execlabelp) {
4614 			mac_cred_label_free(imgp->ip_execlabelp);
4615 			imgp->ip_execlabelp = NULL;
4616 		}
4617 		if (imgp->ip_scriptlabelp) {
4618 			mac_vnode_label_free(imgp->ip_scriptlabelp);
4619 			imgp->ip_scriptlabelp = NULL;
4620 		}
4621 		if (imgp->ip_cs_error != OS_REASON_NULL) {
4622 			os_reason_free(imgp->ip_cs_error);
4623 			imgp->ip_cs_error = OS_REASON_NULL;
4624 		}
4625 		if (imgp->ip_inherited_shared_region_id != NULL) {
4626 			kfree_data(imgp->ip_inherited_shared_region_id,
4627 			    strlen(imgp->ip_inherited_shared_region_id) + 1);
4628 			imgp->ip_inherited_shared_region_id = NULL;
4629 		}
4630 #endif
4631 	}
4632 
4633 #if CONFIG_DTRACE
4634 	if (spawn_no_exec) {
4635 		/*
4636 		 * In the original DTrace reference implementation,
4637 		 * posix_spawn() was a libc routine that just
4638 		 * did vfork(2) then exec(2).  Thus the proc::: probes
4639 		 * are very fork/exec oriented.  The details of this
4640 		 * in-kernel implementation of posix_spawn() is different
4641 		 * (while producing the same process-observable effects)
4642 		 * particularly w.r.t. errors, and which thread/process
4643 		 * is constructing what on behalf of whom.
4644 		 */
4645 		if (error) {
4646 			DTRACE_PROC1(spawn__failure, int, error);
4647 		} else {
4648 			DTRACE_PROC(spawn__success);
4649 			/*
4650 			 * Some DTrace scripts, e.g. newproc.d in
4651 			 * /usr/bin, rely on the the 'exec-success'
4652 			 * probe being fired in the child after the
4653 			 * new process image has been constructed
4654 			 * in order to determine the associated pid.
4655 			 *
4656 			 * So, even though the parent built the image
4657 			 * here, for compatibility, mark the new thread
4658 			 * so 'exec-success' fires on it as it leaves
4659 			 * the kernel.
4660 			 */
4661 			dtrace_thread_didexec(imgp->ip_new_thread);
4662 		}
4663 	} else {
4664 		if (error) {
4665 			DTRACE_PROC1(exec__failure, int, error);
4666 		} else {
4667 			dtrace_thread_didexec(imgp->ip_new_thread);
4668 		}
4669 	}
4670 
4671 	if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4672 		(*dtrace_proc_waitfor_hook)(p);
4673 	}
4674 #endif
4675 
4676 #if CONFIG_AUDIT
4677 	if (!error && AUDIT_ENABLED() && p) {
4678 		/* Add the CDHash of the new process to the audit record */
4679 		uint8_t *cdhash = cs_get_cdhash(p);
4680 		if (cdhash) {
4681 			AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4682 		}
4683 	}
4684 #endif
4685 
4686 	/* terminate the new task if exec failed  */
4687 	if (new_task != NULL && task_is_exec_copy(new_task)) {
4688 		task_terminate_internal(new_task);
4689 	}
4690 
4691 	if (exec_failure_reason && !spawn_no_exec) {
4692 		psignal_with_reason(p, SIGKILL, exec_failure_reason);
4693 		exec_failure_reason = NULL;
4694 	}
4695 
4696 	/* Return to both the parent and the child? */
4697 	if (imgp != NULL && spawn_no_exec) {
4698 		/*
4699 		 * If the parent wants the pid, copy it out
4700 		 */
4701 		if (error == 0 && pid != USER_ADDR_NULL) {
4702 			_Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
4703 			bool aligned = (pid & 3) == 0;
4704 			if (aligned) {
4705 				(void)copyout_atomic32(proc_getpid(p), pid);
4706 			} else {
4707 				(void)suword(pid, proc_getpid(p));
4708 			}
4709 		}
4710 		retval[0] = error;
4711 
4712 		/*
4713 		 * If we had an error, perform an internal reap ; this is
4714 		 * entirely safe, as we have a real process backing us.
4715 		 */
4716 		if (error) {
4717 			proc_list_lock();
4718 			p->p_listflag |= P_LIST_DEADPARENT;
4719 			proc_list_unlock();
4720 			proc_lock(p);
4721 			/* make sure no one else has killed it off... */
4722 			if (p->p_stat != SZOMB && p->exit_thread == NULL) {
4723 				p->exit_thread = current_thread();
4724 				p->p_posix_spawn_failed = true;
4725 				proc_unlock(p);
4726 				exit1(p, 1, (int *)NULL);
4727 			} else {
4728 				/* someone is doing it for us; just skip it */
4729 				proc_unlock(p);
4730 			}
4731 		}
4732 	}
4733 
4734 	/*
4735 	 * Do not terminate the current task, if proc_exec_switch_task did not
4736 	 * switch the tasks, terminating the current task without the switch would
4737 	 * result in loosing the SIGKILL status.
4738 	 */
4739 	if (task_did_exec(old_task)) {
4740 		/* Terminate the current task, since exec will start in new task */
4741 		task_terminate_internal(old_task);
4742 	}
4743 
4744 	/* Release the thread ref returned by cloneproc/fork1 */
4745 	if (imgp != NULL && imgp->ip_new_thread) {
4746 		/* clear the exec complete flag if there is an error before point of no-return */
4747 		uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
4748 		if (!spawn_no_exec && !exec_done && error != 0) {
4749 			clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
4750 		}
4751 		/* wake up the new thread */
4752 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
4753 		thread_deallocate(imgp->ip_new_thread);
4754 		imgp->ip_new_thread = NULL;
4755 	}
4756 
4757 	/* Release the ref returned by cloneproc/fork1 */
4758 	if (new_task) {
4759 		task_deallocate(new_task);
4760 		new_task = NULL;
4761 	}
4762 
4763 	if (should_release_proc_ref) {
4764 		proc_rele(p);
4765 	}
4766 
4767 	kfree_type(typeof(*__spawn_data), __spawn_data);
4768 
4769 	if (inherit != NULL) {
4770 		ipc_importance_release(inherit);
4771 	}
4772 
4773 
4774 	assert(exec_failure_reason == NULL);
4775 	return error;
4776 }
4777 
4778 /*
4779  * proc_exec_switch_task
4780  *
4781  * Parameters:  old_proc		proc before exec
4782  *		new_proc		proc after exec
4783  *		old_task		task before exec
4784  *		new_task		task after exec
4785  *		new_thread		thread in new task
4786  *		inherit			resulting importance linkage
4787  *
4788  * Returns: proc.
4789  *
4790  * Note: The function will switch proc in pid hash from old proc to new proc.
4791  * The switch needs to happen after draining all proc refs and inside
4792  * a proc list lock. In the case of failure to switch the proc, which
4793  * might happen if the process received a SIGKILL or jetsam killed it,
4794  * it will make sure that the new tasks terminates. User proc ref returned
4795  * to caller.
4796  *
4797  * This function is called after point of no return, in the case
4798  * failure to switch, it will terminate the new task and swallow the
4799  * error and let the terminated process complete exec and die.
4800  */
4801 proc_t
proc_exec_switch_task(proc_t old_proc,proc_t new_proc,task_t old_task,task_t new_task,thread_t new_thread,void ** inherit)4802 proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task, task_t new_task, thread_t new_thread,
4803     void **inherit)
4804 {
4805 	boolean_t task_active;
4806 	boolean_t proc_active;
4807 	boolean_t thread_active;
4808 	boolean_t reparent_traced_child = FALSE;
4809 	thread_t old_thread = current_thread();
4810 
4811 	thread_set_exec_promotion(old_thread);
4812 	old_proc = proc_refdrain_will_exec(old_proc);
4813 
4814 	new_proc = proc_refdrain_will_exec(new_proc);
4815 	/* extra proc ref returned to the caller */
4816 
4817 	assert(get_threadtask(new_thread) == new_task);
4818 	task_active = task_is_active(new_task);
4819 	proc_active = !(old_proc->p_lflag & P_LEXIT);
4820 
4821 	/* Check if the current thread is not aborted due to SIGKILL */
4822 	thread_active = thread_is_active(old_thread);
4823 
4824 	/*
4825 	 * Do not switch the proc if the new task or proc is already terminated
4826 	 * as a result of error in exec past point of no return
4827 	 */
4828 	if (proc_active && task_active && thread_active) {
4829 		uthread_t new_uthread = get_bsdthread_info(new_thread);
4830 		uthread_t old_uthread = current_uthread();
4831 
4832 		/* Clear dispatchqueue and workloop ast offset */
4833 		new_proc->p_dispatchqueue_offset = 0;
4834 		new_proc->p_dispatchqueue_serialno_offset = 0;
4835 		new_proc->p_dispatchqueue_label_offset = 0;
4836 		new_proc->p_return_to_kernel_offset = 0;
4837 		new_proc->p_pthread_wq_quantum_offset = 0;
4838 
4839 		/* If old_proc is session leader, change the leader to new proc */
4840 		session_replace_leader(old_proc, new_proc);
4841 
4842 		proc_lock(old_proc);
4843 
4844 		/* Copy the signal state, dtrace state and set bsd ast on new thread */
4845 		act_set_astbsd(new_thread);
4846 		new_uthread->uu_siglist |= old_uthread->uu_siglist;
4847 		new_uthread->uu_siglist |= old_proc->p_siglist;
4848 		new_uthread->uu_sigwait = old_uthread->uu_sigwait;
4849 		new_uthread->uu_sigmask = old_uthread->uu_sigmask;
4850 		new_uthread->uu_oldmask = old_uthread->uu_oldmask;
4851 		new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
4852 #if CONFIG_DTRACE
4853 		new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
4854 		new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
4855 		new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
4856 		assert(new_uthread->t_dtrace_scratch == NULL);
4857 		new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
4858 
4859 		old_uthread->t_dtrace_sig = 0;
4860 		old_uthread->t_dtrace_stop = 0;
4861 		old_uthread->t_dtrace_resumepid = 0;
4862 		old_uthread->t_dtrace_scratch = NULL;
4863 #endif
4864 
4865 #if CONFIG_PROC_UDATA_STORAGE
4866 		new_proc->p_user_data = old_proc->p_user_data;
4867 #endif /* CONFIG_PROC_UDATA_STORAGE */
4868 
4869 		/* Copy the resource accounting info */
4870 		thread_copy_resource_info(new_thread, current_thread());
4871 
4872 		/* Clear the exit reason and signal state on old thread */
4873 		old_uthread->uu_exit_reason = NULL;
4874 		old_uthread->uu_siglist = 0;
4875 
4876 		task_set_did_exec_flag(old_task);
4877 		task_clear_exec_copy_flag(new_task);
4878 
4879 		task_copy_fields_for_exec(new_task, old_task);
4880 
4881 		/*
4882 		 * Need to transfer pending watch port boosts to the new task
4883 		 * while still making sure that the old task remains in the
4884 		 * importance linkage. Create an importance linkage from old task
4885 		 * to new task, then switch the task importance base of old task
4886 		 * and new task. After the switch the port watch boost will be
4887 		 * boosting the new task and new task will be donating importance
4888 		 * to old task.
4889 		 */
4890 		*inherit = ipc_importance_exec_switch_task(old_task, new_task);
4891 
4892 		/* Transfer parent's ptrace state to child */
4893 		new_proc->p_lflag &= ~(P_LTRACED | P_LSIGEXC | P_LNOATTACH);
4894 		new_proc->p_lflag |= (old_proc->p_lflag & (P_LTRACED | P_LSIGEXC | P_LNOATTACH));
4895 		new_proc->p_oppid = old_proc->p_oppid;
4896 
4897 		if (old_proc->p_pptr != new_proc->p_pptr) {
4898 			reparent_traced_child = TRUE;
4899 			new_proc->p_lflag |= P_LTRACE_WAIT;
4900 		}
4901 
4902 		proc_unlock(old_proc);
4903 
4904 		/* Update the list of proc knotes */
4905 		proc_transfer_knotes(old_proc, new_proc);
4906 
4907 		/* Update the proc interval timers */
4908 		proc_inherit_itimers(old_proc, new_proc);
4909 
4910 		proc_list_lock();
4911 
4912 		/* Insert the new proc in child list of parent proc */
4913 		p_reparentallchildren(old_proc, new_proc);
4914 
4915 		/* Switch proc in pid hash */
4916 		phash_replace_locked(old_proc, new_proc);
4917 
4918 		/* Transfer the shadow flag to old proc */
4919 		os_atomic_andnot(&new_proc->p_refcount, P_REF_SHADOW, relaxed);
4920 		os_atomic_or(&old_proc->p_refcount, P_REF_SHADOW, relaxed);
4921 
4922 		/* Change init proc if launchd exec */
4923 		if (old_proc == initproc) {
4924 			/* Take the ref on new proc after proc_refwake_did_exec */
4925 			initproc = new_proc;
4926 			/* Drop the proc ref on old proc */
4927 			proc_rele(old_proc);
4928 		}
4929 
4930 		proc_list_unlock();
4931 	} else {
4932 		task_terminate_internal(new_task);
4933 	}
4934 
4935 	proc_refwake_did_exec(new_proc);
4936 	proc_refwake_did_exec(old_proc);
4937 
4938 	/* Take a ref on initproc if it changed */
4939 	if (new_proc == initproc) {
4940 		initproc = proc_ref(new_proc, false);
4941 		assert(initproc != PROC_NULL);
4942 	}
4943 
4944 	thread_clear_exec_promotion(old_thread);
4945 	proc_rele(old_proc);
4946 
4947 	if (reparent_traced_child) {
4948 		proc_t pp = proc_parent(old_proc);
4949 		assert(pp != PROC_NULL);
4950 
4951 		proc_reparentlocked(new_proc, pp, 1, 0);
4952 		proc_rele(pp);
4953 
4954 		proc_lock(new_proc);
4955 		new_proc->p_lflag &= ~P_LTRACE_WAIT;
4956 		proc_unlock(new_proc);
4957 	}
4958 
4959 	return new_proc;
4960 }
4961 
4962 /*
4963  * execve
4964  *
4965  * Parameters:	uap->fname		File name to exec
4966  *		uap->argp		Argument list
4967  *		uap->envp		Environment list
4968  *
4969  * Returns:	0			Success
4970  *	__mac_execve:EINVAL		Invalid argument
4971  *	__mac_execve:ENOTSUP		Invalid argument
4972  *	__mac_execve:EACCES		Permission denied
4973  *	__mac_execve:EINTR		Interrupted function
4974  *	__mac_execve:ENOMEM		Not enough space
4975  *	__mac_execve:EFAULT		Bad address
4976  *	__mac_execve:ENAMETOOLONG	Filename too long
4977  *	__mac_execve:ENOEXEC		Executable file format error
4978  *	__mac_execve:ETXTBSY		Text file busy [misuse of error code]
4979  *	__mac_execve:???
4980  *
4981  * TODO:	Dynamic linker header address on stack is copied via suword()
4982  */
4983 /* ARGSUSED */
4984 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)4985 execve(proc_t p, struct execve_args *uap, int32_t *retval)
4986 {
4987 	struct __mac_execve_args muap;
4988 	int err;
4989 
4990 	memoryshot(VM_EXECVE, DBG_FUNC_NONE);
4991 
4992 	muap.fname = uap->fname;
4993 	muap.argp = uap->argp;
4994 	muap.envp = uap->envp;
4995 	muap.mac_p = USER_ADDR_NULL;
4996 	err = __mac_execve(p, &muap, retval);
4997 
4998 	return err;
4999 }
5000 
5001 /*
5002  * __mac_execve
5003  *
5004  * Parameters:	uap->fname		File name to exec
5005  *		uap->argp		Argument list
5006  *		uap->envp		Environment list
5007  *		uap->mac_p		MAC label supplied by caller
5008  *
5009  * Returns:	0			Success
5010  *		EINVAL			Invalid argument
5011  *		ENOTSUP			Not supported
5012  *		ENOEXEC			Executable file format error
5013  *	exec_activate_image:EINVAL	Invalid argument
5014  *	exec_activate_image:EACCES	Permission denied
5015  *	exec_activate_image:EINTR	Interrupted function
5016  *	exec_activate_image:ENOMEM	Not enough space
5017  *	exec_activate_image:EFAULT	Bad address
5018  *	exec_activate_image:ENAMETOOLONG	Filename too long
5019  *	exec_activate_image:ENOEXEC	Executable file format error
5020  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
5021  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
5022  *	exec_activate_image:???
5023  *	mac_execve_enter:???
5024  *
5025  * TODO:	Dynamic linker header address on stack is copied via suword()
5026  */
5027 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)5028 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
5029 {
5030 	struct image_params *imgp = NULL;
5031 	struct vnode_attr *vap = NULL;
5032 	struct vnode_attr *origvap = NULL;
5033 	int error;
5034 	int is_64 = IS_64BIT_PROCESS(p);
5035 	struct vfs_context context;
5036 	struct uthread  *uthread = NULL;
5037 	task_t old_task = current_task();
5038 	task_t new_task = NULL;
5039 	boolean_t should_release_proc_ref = FALSE;
5040 	boolean_t exec_done = FALSE;
5041 	void *inherit = NULL;
5042 	struct {
5043 		struct image_params imgp;
5044 		struct vnode_attr va;
5045 		struct vnode_attr origva;
5046 	} *__execve_data;
5047 
5048 	/* Allocate a big chunk for locals instead of using stack since these
5049 	 * structures a pretty big.
5050 	 */
5051 	__execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
5052 	if (__execve_data == NULL) {
5053 		error = ENOMEM;
5054 		goto exit_with_error;
5055 	}
5056 	imgp = &__execve_data->imgp;
5057 	vap = &__execve_data->va;
5058 	origvap = &__execve_data->origva;
5059 
5060 	/* Initialize the common data in the image_params structure */
5061 	imgp->ip_user_fname = uap->fname;
5062 	imgp->ip_user_argv = uap->argp;
5063 	imgp->ip_user_envv = uap->envp;
5064 	imgp->ip_vattr = vap;
5065 	imgp->ip_origvattr = origvap;
5066 	imgp->ip_vfs_context = &context;
5067 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
5068 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
5069 	imgp->ip_mac_return = 0;
5070 	imgp->ip_cs_error = OS_REASON_NULL;
5071 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
5072 	imgp->ip_subsystem_root_path = NULL;
5073 	uthread_set_exec_data(current_uthread(), imgp);
5074 
5075 #if CONFIG_MACF
5076 	if (uap->mac_p != USER_ADDR_NULL) {
5077 		error = mac_execve_enter(uap->mac_p, imgp);
5078 		if (error) {
5079 			goto exit_with_error;
5080 		}
5081 	}
5082 #endif
5083 	uthread = current_uthread();
5084 	{
5085 		imgp->ip_flags |= IMGPF_EXEC;
5086 
5087 		/* Adjust the user proc count */
5088 		(void)chgproccnt(kauth_getruid(), 1);
5089 		/*
5090 		 * For execve case, create a new proc, task and thread
5091 		 * but don't make the proc visible to userland. After
5092 		 * image activation, the new proc would take place of
5093 		 * the old proc in pid hash and other lists that make
5094 		 * the proc visible to the system.
5095 		 */
5096 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_FLAGS_FOR_EXEC);
5097 		/* task and thread ref returned by cloneproc */
5098 		if (imgp->ip_new_thread == NULL) {
5099 			(void)chgproccnt(kauth_getruid(), -1);
5100 			error = ENOMEM;
5101 			goto exit_with_error;
5102 		}
5103 
5104 		new_task = get_threadtask(imgp->ip_new_thread);
5105 	}
5106 
5107 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
5108 
5109 	context.vc_thread = imgp->ip_new_thread;
5110 	context.vc_ucred = kauth_cred_proc_ref(p);      /* XXX must NOT be kauth_cred_get() */
5111 
5112 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
5113 
5114 	proc_transend(p, 0);
5115 	proc_signalend(p, 0);
5116 
5117 	/*
5118 	 * Activate the image.
5119 	 * Warning: If activation failed after point of no return, it returns error
5120 	 * as 0 and pretends the call succeeded.
5121 	 */
5122 	error = exec_activate_image(imgp);
5123 	/* thread and task ref returned for vfexec case */
5124 
5125 	if (imgp->ip_new_thread != NULL) {
5126 		/*
5127 		 * task reference might be returned by exec_activate_image
5128 		 * for vfexec.
5129 		 */
5130 		new_task = get_threadtask(imgp->ip_new_thread);
5131 #if defined(HAS_APPLE_PAC)
5132 		ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5133 		ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5134 #endif
5135 	}
5136 
5137 	if (!error) {
5138 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp->ip_new_thread, &inherit);
5139 		/* proc ref returned */
5140 		should_release_proc_ref = TRUE;
5141 	}
5142 
5143 	kauth_cred_unref(&context.vc_ucred);
5144 
5145 	if (!error) {
5146 		exec_done = TRUE;
5147 		assert(imgp->ip_new_thread != NULL);
5148 		/*
5149 		 * Enable new task IPC access if exec_activate_image() returned an
5150 		 * active task. (Checks active bit in ipc_task_enable() under lock).
5151 		 */
5152 		ipc_task_enable(new_task);
5153 
5154 		exec_resettextvp(p, imgp);
5155 		error = process_signature(p, imgp);
5156 	}
5157 
5158 #if defined(HAS_APPLE_PAC)
5159 	if (imgp->ip_new_thread && !error) {
5160 		ml_task_set_jop_pid_from_shared_region(new_task);
5161 		ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
5162 	}
5163 #endif /* defined(HAS_APPLE_PAC) */
5164 
5165 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
5166 	if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
5167 		proc_knote(p, NOTE_EXEC);
5168 	}
5169 
5170 	if (imgp->ip_vp != NULLVP) {
5171 		vnode_put(imgp->ip_vp);
5172 	}
5173 	if (imgp->ip_scriptvp != NULLVP) {
5174 		vnode_put(imgp->ip_scriptvp);
5175 	}
5176 	if (imgp->ip_free_map) {
5177 		/* Free the map after dropping iocount on vnode to avoid deadlock */
5178 		vm_map_deallocate(imgp->ip_free_map);
5179 	}
5180 	if (imgp->ip_strings) {
5181 		execargs_free(imgp);
5182 	}
5183 #if CONFIG_MACF
5184 	if (imgp->ip_execlabelp) {
5185 		mac_cred_label_free(imgp->ip_execlabelp);
5186 		imgp->ip_execlabelp = NULL;
5187 	}
5188 	if (imgp->ip_scriptlabelp) {
5189 		mac_vnode_label_free(imgp->ip_scriptlabelp);
5190 		imgp->ip_scriptlabelp = NULL;
5191 	}
5192 #endif
5193 	if (imgp->ip_cs_error != OS_REASON_NULL) {
5194 		os_reason_free(imgp->ip_cs_error);
5195 		imgp->ip_cs_error = OS_REASON_NULL;
5196 	}
5197 
5198 	if (!error) {
5199 		/*
5200 		 * We need to initialize the bank context behind the protection of
5201 		 * the proc_trans lock to prevent a race with exit. We can't do this during
5202 		 * exec_activate_image because task_bank_init checks entitlements that
5203 		 * aren't loaded until subsequent calls (including exec_resettextvp).
5204 		 */
5205 		error = proc_transstart(p, 0, 0);
5206 	}
5207 
5208 	if (!error) {
5209 		task_bank_init(new_task);
5210 		proc_transend(p, 0);
5211 
5212 		// Don't inherit crash behavior across exec
5213 		p->p_crash_behavior = 0;
5214 		p->p_crash_behavior_deadline = 0;
5215 
5216 #if __arm64__
5217 		proc_footprint_entitlement_hacks(p, new_task);
5218 #endif /* __arm64__ */
5219 
5220 #if XNU_TARGET_OS_OSX
5221 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
5222 			vm_map_single_jit(get_task_map(new_task));
5223 		}
5224 #endif /* XNU_TARGET_OS_OSX */
5225 
5226 		/* Sever any extant thread affinity */
5227 		thread_affinity_exec(current_thread());
5228 
5229 		/* Inherit task role from old task to new task for exec */
5230 		proc_inherit_task_role(new_task, old_task);
5231 
5232 		thread_t main_thread = imgp->ip_new_thread;
5233 
5234 		task_set_main_thread_qos(new_task, main_thread);
5235 
5236 #if __has_feature(ptrauth_calls)
5237 		task_set_pac_exception_fatal_flag(new_task);
5238 #endif /* __has_feature(ptrauth_calls) */
5239 
5240 #if CONFIG_ARCADE
5241 		/*
5242 		 * Check to see if we need to trigger an arcade upcall AST now
5243 		 * that the vnode has been reset on the task.
5244 		 */
5245 		arcade_prepare(new_task, imgp->ip_new_thread);
5246 #endif /* CONFIG_ARCADE */
5247 
5248 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
5249 
5250 		if (vm_darkwake_mode == TRUE) {
5251 			/*
5252 			 * This process is being launched when the system
5253 			 * is in darkwake. So mark it specially. This will
5254 			 * cause all its pages to be entered in the background Q.
5255 			 */
5256 			task_set_darkwake_mode(new_task, vm_darkwake_mode);
5257 		}
5258 
5259 #if CONFIG_DTRACE
5260 		dtrace_thread_didexec(imgp->ip_new_thread);
5261 
5262 		if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5263 			(*dtrace_proc_waitfor_hook)(p);
5264 		}
5265 #endif
5266 
5267 #if CONFIG_AUDIT
5268 		if (!error && AUDIT_ENABLED() && p) {
5269 			/* Add the CDHash of the new process to the audit record */
5270 			uint8_t *cdhash = cs_get_cdhash(p);
5271 			if (cdhash) {
5272 				AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5273 			}
5274 		}
5275 #endif
5276 	} else {
5277 		DTRACE_PROC1(exec__failure, int, error);
5278 	}
5279 
5280 exit_with_error:
5281 
5282 	/* terminate the new task it if exec failed  */
5283 	if (new_task != NULL && task_is_exec_copy(new_task)) {
5284 		task_terminate_internal(new_task);
5285 	}
5286 
5287 	if (imgp != NULL) {
5288 		/* Clear the initial wait on the thread transferring watchports */
5289 		if (imgp->ip_new_thread) {
5290 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
5291 		}
5292 
5293 		/* Transfer the watchport boost to new task */
5294 		if (!error) {
5295 			task_transfer_turnstile_watchports(old_task,
5296 			    new_task, imgp->ip_new_thread);
5297 		}
5298 		/*
5299 		 * Do not terminate the current task, if proc_exec_switch_task did not
5300 		 * switch the tasks, terminating the current task without the switch would
5301 		 * result in loosing the SIGKILL status.
5302 		 */
5303 		if (task_did_exec(old_task)) {
5304 			/* Terminate the current task, since exec will start in new task */
5305 			task_terminate_internal(old_task);
5306 		}
5307 
5308 		/* Release the thread ref returned by cloneproc */
5309 		if (imgp->ip_new_thread) {
5310 			/* clear the exec complete flag if there is an error before point of no-return */
5311 			uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5312 			if (!exec_done && error != 0) {
5313 				clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5314 			}
5315 			/* wake up the new exec thread */
5316 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5317 			thread_deallocate(imgp->ip_new_thread);
5318 			imgp->ip_new_thread = NULL;
5319 		}
5320 	}
5321 
5322 	/* Release the ref returned by fork_create_child */
5323 	if (new_task) {
5324 		task_deallocate(new_task);
5325 		new_task = NULL;
5326 	}
5327 
5328 	if (should_release_proc_ref) {
5329 		proc_rele(p);
5330 	}
5331 
5332 	uthread_set_exec_data(current_uthread(), NULL);
5333 	kfree_type(typeof(*__execve_data), __execve_data);
5334 
5335 	if (inherit != NULL) {
5336 		ipc_importance_release(inherit);
5337 	}
5338 
5339 	return error;
5340 }
5341 
5342 
5343 /*
5344  * copyinptr
5345  *
5346  * Description:	Copy a pointer in from user space to a user_addr_t in kernel
5347  *		space, based on 32/64 bitness of the user space
5348  *
5349  * Parameters:	froma			User space address
5350  *		toptr			Address of kernel space user_addr_t
5351  *		ptr_size		4/8, based on 'froma' address space
5352  *
5353  * Returns:	0			Success
5354  *		EFAULT			Bad 'froma'
5355  *
5356  * Implicit returns:
5357  *		*ptr_size		Modified
5358  */
5359 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)5360 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
5361 {
5362 	int error;
5363 
5364 	if (ptr_size == 4) {
5365 		/* 64 bit value containing 32 bit address */
5366 		unsigned int i = 0;
5367 
5368 		error = copyin(froma, &i, 4);
5369 		*toptr = CAST_USER_ADDR_T(i);   /* SAFE */
5370 	} else {
5371 		error = copyin(froma, toptr, 8);
5372 	}
5373 	return error;
5374 }
5375 
5376 
5377 /*
5378  * copyoutptr
5379  *
5380  * Description:	Copy a pointer out from a user_addr_t in kernel space to
5381  *		user space, based on 32/64 bitness of the user space
5382  *
5383  * Parameters:	ua			User space address to copy to
5384  *		ptr			Address of kernel space user_addr_t
5385  *		ptr_size		4/8, based on 'ua' address space
5386  *
5387  * Returns:	0			Success
5388  *		EFAULT			Bad 'ua'
5389  *
5390  */
5391 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)5392 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
5393 {
5394 	int error;
5395 
5396 	if (ptr_size == 4) {
5397 		/* 64 bit value containing 32 bit address */
5398 		unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua);   /* SAFE */
5399 
5400 		error = copyout(&i, ptr, 4);
5401 	} else {
5402 		error = copyout(&ua, ptr, 8);
5403 	}
5404 	return error;
5405 }
5406 
5407 
5408 /*
5409  * exec_copyout_strings
5410  *
5411  * Copy out the strings segment to user space.  The strings segment is put
5412  * on a preinitialized stack frame.
5413  *
5414  * Parameters:	struct image_params *	the image parameter block
5415  *		int *			a pointer to the stack offset variable
5416  *
5417  * Returns:	0			Success
5418  *		!0			Faiure: errno
5419  *
5420  * Implicit returns:
5421  *		(*stackp)		The stack offset, modified
5422  *
5423  * Note:	The strings segment layout is backward, from the beginning
5424  *		of the top of the stack to consume the minimal amount of
5425  *		space possible; the returned stack pointer points to the
5426  *		end of the area consumed (stacks grow downward).
5427  *
5428  *		argc is an int; arg[i] are pointers; env[i] are pointers;
5429  *		the 0's are (void *)NULL's
5430  *
5431  * The stack frame layout is:
5432  *
5433  *      +-------------+ <- p->user_stack
5434  *      |     16b     |
5435  *      +-------------+
5436  *      | STRING AREA |
5437  *      |      :      |
5438  *      |      :      |
5439  *      |      :      |
5440  *      +- -- -- -- --+
5441  *      |  PATH AREA  |
5442  *      +-------------+
5443  *      |      0      |
5444  *      +-------------+
5445  *      |  applev[n]  |
5446  *      +-------------+
5447  *             :
5448  *             :
5449  *      +-------------+
5450  *      |  applev[1]  |
5451  *      +-------------+
5452  *      | exec_path / |
5453  *      |  applev[0]  |
5454  *      +-------------+
5455  *      |      0      |
5456  *      +-------------+
5457  *      |    env[n]   |
5458  *      +-------------+
5459  *             :
5460  *             :
5461  *      +-------------+
5462  *      |    env[0]   |
5463  *      +-------------+
5464  *      |      0      |
5465  *      +-------------+
5466  *      | arg[argc-1] |
5467  *      +-------------+
5468  *             :
5469  *             :
5470  *      +-------------+
5471  *      |    arg[0]   |
5472  *      +-------------+
5473  *      |     argc    |
5474  * sp-> +-------------+
5475  *
5476  * Although technically a part of the STRING AREA, we treat the PATH AREA as
5477  * a separate entity.  This allows us to align the beginning of the PATH AREA
5478  * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
5479  * which preceed it on the stack are properly aligned.
5480  */
5481 __attribute__((noinline))
5482 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)5483 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
5484 {
5485 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5486 	int     ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5487 	int     ptr_area_size;
5488 	void *ptr_buffer_start, *ptr_buffer;
5489 	size_t string_size;
5490 
5491 	user_addr_t     string_area;    /* *argv[], *env[] */
5492 	user_addr_t     ptr_area;       /* argv[], env[], applev[] */
5493 	user_addr_t argc_area;  /* argc */
5494 	user_addr_t     stack;
5495 	int error;
5496 
5497 	unsigned i;
5498 	struct copyout_desc {
5499 		char    *start_string;
5500 		int             count;
5501 #if CONFIG_DTRACE
5502 		user_addr_t     *dtrace_cookie;
5503 #endif
5504 		boolean_t       null_term;
5505 	} descriptors[] = {
5506 		{
5507 			.start_string = imgp->ip_startargv,
5508 			.count = imgp->ip_argc,
5509 #if CONFIG_DTRACE
5510 			.dtrace_cookie = &p->p_dtrace_argv,
5511 #endif
5512 			.null_term = TRUE
5513 		},
5514 		{
5515 			.start_string = imgp->ip_endargv,
5516 			.count = imgp->ip_envc,
5517 #if CONFIG_DTRACE
5518 			.dtrace_cookie = &p->p_dtrace_envp,
5519 #endif
5520 			.null_term = TRUE
5521 		},
5522 		{
5523 			.start_string = imgp->ip_strings,
5524 			.count = 1,
5525 #if CONFIG_DTRACE
5526 			.dtrace_cookie = NULL,
5527 #endif
5528 			.null_term = FALSE
5529 		},
5530 		{
5531 			.start_string = imgp->ip_endenvv,
5532 			.count = imgp->ip_applec - 1, /* exec_path handled above */
5533 #if CONFIG_DTRACE
5534 			.dtrace_cookie = NULL,
5535 #endif
5536 			.null_term = TRUE
5537 		}
5538 	};
5539 
5540 	stack = *stackp;
5541 
5542 	/*
5543 	 * All previous contributors to the string area
5544 	 * should have aligned their sub-area
5545 	 */
5546 	if (imgp->ip_strspace % ptr_size != 0) {
5547 		error = EINVAL;
5548 		goto bad;
5549 	}
5550 
5551 	/* Grow the stack down for the strings we've been building up */
5552 	string_size = imgp->ip_strendp - imgp->ip_strings;
5553 	stack -= string_size;
5554 	string_area = stack;
5555 
5556 	/*
5557 	 * Need room for one pointer for each string, plus
5558 	 * one for the NULLs terminating the argv, envv, and apple areas.
5559 	 */
5560 	ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5561 	stack -= ptr_area_size;
5562 	ptr_area = stack;
5563 
5564 	/* We'll construct all the pointer arrays in our string buffer,
5565 	 * which we already know is aligned properly, and ip_argspace
5566 	 * was used to verify we have enough space.
5567 	 */
5568 	ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5569 
5570 	/*
5571 	 * Need room for pointer-aligned argc slot.
5572 	 */
5573 	stack -= ptr_size;
5574 	argc_area = stack;
5575 
5576 	/*
5577 	 * Record the size of the arguments area so that sysctl_procargs()
5578 	 * can return the argument area without having to parse the arguments.
5579 	 */
5580 	proc_lock(p);
5581 	p->p_argc = imgp->ip_argc;
5582 	p->p_argslen = (int)(*stackp - string_area);
5583 	proc_unlock(p);
5584 
5585 	/* Return the initial stack address: the location of argc */
5586 	*stackp = stack;
5587 
5588 	/*
5589 	 * Copy out the entire strings area.
5590 	 */
5591 	error = copyout(imgp->ip_strings, string_area,
5592 	    string_size);
5593 	if (error) {
5594 		goto bad;
5595 	}
5596 
5597 	for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
5598 		char *cur_string = descriptors[i].start_string;
5599 		int j;
5600 
5601 #if CONFIG_DTRACE
5602 		if (descriptors[i].dtrace_cookie) {
5603 			proc_lock(p);
5604 			*descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
5605 			proc_unlock(p);
5606 		}
5607 #endif /* CONFIG_DTRACE */
5608 
5609 		/*
5610 		 * For each segment (argv, envv, applev), copy as many pointers as requested
5611 		 * to our pointer buffer.
5612 		 */
5613 		for (j = 0; j < descriptors[i].count; j++) {
5614 			user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
5615 
5616 			/* Copy out the pointer to the current string. Alignment has been verified  */
5617 			if (ptr_size == 8) {
5618 				*(uint64_t *)ptr_buffer = (uint64_t)cur_address;
5619 			} else {
5620 				*(uint32_t *)ptr_buffer = (uint32_t)cur_address;
5621 			}
5622 
5623 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5624 			cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
5625 		}
5626 
5627 		if (descriptors[i].null_term) {
5628 			if (ptr_size == 8) {
5629 				*(uint64_t *)ptr_buffer = 0ULL;
5630 			} else {
5631 				*(uint32_t *)ptr_buffer = 0;
5632 			}
5633 
5634 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5635 		}
5636 	}
5637 
5638 	/*
5639 	 * Copy out all our pointer arrays in bulk.
5640 	 */
5641 	error = copyout(ptr_buffer_start, ptr_area,
5642 	    ptr_area_size);
5643 	if (error) {
5644 		goto bad;
5645 	}
5646 
5647 	/* argc (int32, stored in a ptr_size area) */
5648 	error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
5649 	if (error) {
5650 		goto bad;
5651 	}
5652 
5653 bad:
5654 	return error;
5655 }
5656 
5657 
5658 /*
5659  * exec_extract_strings
5660  *
5661  * Copy arguments and environment from user space into work area; we may
5662  * have already copied some early arguments into the work area, and if
5663  * so, any arguments opied in are appended to those already there.
5664  * This function is the primary manipulator of ip_argspace, since
5665  * these are the arguments the client of execve(2) knows about. After
5666  * each argv[]/envv[] string is copied, we charge the string length
5667  * and argv[]/envv[] pointer slot to ip_argspace, so that we can
5668  * full preflight the arg list size.
5669  *
5670  * Parameters:	struct image_params *	the image parameter block
5671  *
5672  * Returns:	0			Success
5673  *		!0			Failure: errno
5674  *
5675  * Implicit returns;
5676  *		(imgp->ip_argc)		Count of arguments, updated
5677  *		(imgp->ip_envc)		Count of environment strings, updated
5678  *		(imgp->ip_argspace)	Count of remaining of NCARGS
5679  *		(imgp->ip_interp_buffer)	Interpreter and args (mutated in place)
5680  *
5681  *
5682  * Note:	The argument and environment vectors are user space pointers
5683  *		to arrays of user space pointers.
5684  */
5685 __attribute__((noinline))
5686 static int
exec_extract_strings(struct image_params * imgp)5687 exec_extract_strings(struct image_params *imgp)
5688 {
5689 	int error = 0;
5690 	int     ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
5691 	int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5692 	user_addr_t     argv = imgp->ip_user_argv;
5693 	user_addr_t     envv = imgp->ip_user_envv;
5694 
5695 	/*
5696 	 * Adjust space reserved for the path name by however much padding it
5697 	 * needs. Doing this here since we didn't know if this would be a 32-
5698 	 * or 64-bit process back in exec_save_path.
5699 	 */
5700 	while (imgp->ip_strspace % new_ptr_size != 0) {
5701 		*imgp->ip_strendp++ = '\0';
5702 		imgp->ip_strspace--;
5703 		/* imgp->ip_argspace--; not counted towards exec args total */
5704 	}
5705 
5706 	/*
5707 	 * From now on, we start attributing string space to ip_argspace
5708 	 */
5709 	imgp->ip_startargv = imgp->ip_strendp;
5710 	imgp->ip_argc = 0;
5711 
5712 	if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
5713 		user_addr_t     arg;
5714 		char *argstart, *ch;
5715 
5716 		/* First, the arguments in the "#!" string are tokenized and extracted. */
5717 		argstart = imgp->ip_interp_buffer;
5718 		while (argstart) {
5719 			ch = argstart;
5720 			while (*ch && !IS_WHITESPACE(*ch)) {
5721 				ch++;
5722 			}
5723 
5724 			if (*ch == '\0') {
5725 				/* last argument, no need to NUL-terminate */
5726 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5727 				argstart = NULL;
5728 			} else {
5729 				/* NUL-terminate */
5730 				*ch = '\0';
5731 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5732 
5733 				/*
5734 				 * Find the next string. We know spaces at the end of the string have already
5735 				 * been stripped.
5736 				 */
5737 				argstart = ch + 1;
5738 				while (IS_WHITESPACE(*argstart)) {
5739 					argstart++;
5740 				}
5741 			}
5742 
5743 			/* Error-check, regardless of whether this is the last interpreter arg or not */
5744 			if (error) {
5745 				goto bad;
5746 			}
5747 			if (imgp->ip_argspace < new_ptr_size) {
5748 				error = E2BIG;
5749 				goto bad;
5750 			}
5751 			imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5752 			imgp->ip_argc++;
5753 		}
5754 
5755 		if (argv != 0LL) {
5756 			/*
5757 			 * If we are running an interpreter, replace the av[0] that was
5758 			 * passed to execve() with the path name that was
5759 			 * passed to execve() for interpreters which do not use the PATH
5760 			 * to locate their script arguments.
5761 			 */
5762 			error = copyinptr(argv, &arg, ptr_size);
5763 			if (error) {
5764 				goto bad;
5765 			}
5766 			if (arg != 0LL) {
5767 				argv += ptr_size; /* consume without using */
5768 			}
5769 		}
5770 
5771 		if (imgp->ip_interp_sugid_fd != -1) {
5772 			char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
5773 			snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
5774 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
5775 		} else {
5776 			error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
5777 		}
5778 
5779 		if (error) {
5780 			goto bad;
5781 		}
5782 		if (imgp->ip_argspace < new_ptr_size) {
5783 			error = E2BIG;
5784 			goto bad;
5785 		}
5786 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5787 		imgp->ip_argc++;
5788 	}
5789 
5790 	while (argv != 0LL) {
5791 		user_addr_t     arg;
5792 
5793 		error = copyinptr(argv, &arg, ptr_size);
5794 		if (error) {
5795 			goto bad;
5796 		}
5797 
5798 		if (arg == 0LL) {
5799 			break;
5800 		}
5801 
5802 		argv += ptr_size;
5803 
5804 		/*
5805 		 * av[n...] = arg[n]
5806 		 */
5807 		error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
5808 		if (error) {
5809 			goto bad;
5810 		}
5811 		if (imgp->ip_argspace < new_ptr_size) {
5812 			error = E2BIG;
5813 			goto bad;
5814 		}
5815 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5816 		imgp->ip_argc++;
5817 	}
5818 
5819 	/* Save space for argv[] NULL terminator */
5820 	if (imgp->ip_argspace < new_ptr_size) {
5821 		error = E2BIG;
5822 		goto bad;
5823 	}
5824 	imgp->ip_argspace -= new_ptr_size;
5825 
5826 	/* Note where the args ends and env begins. */
5827 	imgp->ip_endargv = imgp->ip_strendp;
5828 	imgp->ip_envc = 0;
5829 
5830 	/* Now, get the environment */
5831 	while (envv != 0LL) {
5832 		user_addr_t     env;
5833 
5834 		error = copyinptr(envv, &env, ptr_size);
5835 		if (error) {
5836 			goto bad;
5837 		}
5838 
5839 		envv += ptr_size;
5840 		if (env == 0LL) {
5841 			break;
5842 		}
5843 		/*
5844 		 * av[n...] = env[n]
5845 		 */
5846 		error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
5847 		if (error) {
5848 			goto bad;
5849 		}
5850 		if (imgp->ip_argspace < new_ptr_size) {
5851 			error = E2BIG;
5852 			goto bad;
5853 		}
5854 		imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
5855 		imgp->ip_envc++;
5856 	}
5857 
5858 	/* Save space for envv[] NULL terminator */
5859 	if (imgp->ip_argspace < new_ptr_size) {
5860 		error = E2BIG;
5861 		goto bad;
5862 	}
5863 	imgp->ip_argspace -= new_ptr_size;
5864 
5865 	/* Align the tail of the combined argv+envv area */
5866 	while (imgp->ip_strspace % new_ptr_size != 0) {
5867 		if (imgp->ip_argspace < 1) {
5868 			error = E2BIG;
5869 			goto bad;
5870 		}
5871 		*imgp->ip_strendp++ = '\0';
5872 		imgp->ip_strspace--;
5873 		imgp->ip_argspace--;
5874 	}
5875 
5876 	/* Note where the envv ends and applev begins. */
5877 	imgp->ip_endenvv = imgp->ip_strendp;
5878 
5879 	/*
5880 	 * From now on, we are no longer charging argument
5881 	 * space to ip_argspace.
5882 	 */
5883 
5884 bad:
5885 	return error;
5886 }
5887 
5888 /*
5889  * Libc has an 8-element array set up for stack guard values.  It only fills
5890  * in one of those entries, and both gcc and llvm seem to use only a single
5891  * 8-byte guard.  Until somebody needs more than an 8-byte guard value, don't
5892  * do the work to construct them.
5893  */
5894 #define GUARD_VALUES 1
5895 #define GUARD_KEY "stack_guard="
5896 
5897 /*
5898  * System malloc needs some entropy when it is initialized.
5899  */
5900 #define ENTROPY_VALUES 2
5901 #define ENTROPY_KEY "malloc_entropy="
5902 
5903 /*
5904  * libplatform needs a random pointer-obfuscation value when it is initialized.
5905  */
5906 #define PTR_MUNGE_VALUES 1
5907 #define PTR_MUNGE_KEY "ptr_munge="
5908 
5909 /*
5910  * System malloc engages nanozone for UIAPP.
5911  */
5912 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
5913 
5914 /*
5915  * System malloc uses deferred reclaim
5916  * for UIAPP on embedded systems with swap.
5917  */
5918 #define RECLAIM_ENGAGE_KEY "MallocDeferredReclaim=1"
5919 /*
5920  * Used to pass experiment flags up to libmalloc.
5921  */
5922 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
5923 
5924 #define PFZ_KEY "pfz="
5925 extern user32_addr_t commpage_text32_location;
5926 extern user64_addr_t commpage_text64_location;
5927 
5928 extern uuid_string_t bootsessionuuid_string;
5929 static TUNABLE(uint32_t, exe_boothash_salt, "exe_boothash_salt", 0);
5930 
5931 __startup_func
5932 static void
exe_boothash_salt_generate(void)5933 exe_boothash_salt_generate(void)
5934 {
5935 	if (!PE_parse_boot_argn("exe_boothash_salt", NULL, 0)) {
5936 		read_random(&exe_boothash_salt, sizeof(exe_boothash_salt));
5937 	}
5938 }
5939 STARTUP(EARLY_BOOT, STARTUP_RANK_MIDDLE, exe_boothash_salt_generate);
5940 
5941 
5942 #define MAIN_STACK_VALUES 4
5943 #define MAIN_STACK_KEY "main_stack="
5944 
5945 #define FSID_KEY "executable_file="
5946 #define DYLD_FSID_KEY "dyld_file="
5947 #define CDHASH_KEY "executable_cdhash="
5948 #define DYLD_FLAGS_KEY "dyld_flags="
5949 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
5950 #define APP_BOOT_SESSION_KEY "executable_boothash="
5951 #if __has_feature(ptrauth_calls)
5952 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
5953 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
5954 #endif /* __has_feature(ptrauth_calls) */
5955 #define MAIN_TH_PORT_KEY "th_port="
5956 
5957 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
5958 
5959 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
5960 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
5961 
5962 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
5963 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
5964 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
5965 
5966 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)5967 exec_add_entropy_key(struct image_params *imgp,
5968     const char *key,
5969     int values,
5970     boolean_t embedNUL)
5971 {
5972 	const int limit = 8;
5973 	uint64_t entropy[limit];
5974 	char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
5975 	if (values > limit) {
5976 		values = limit;
5977 	}
5978 
5979 	read_random(entropy, sizeof(entropy[0]) * values);
5980 
5981 	if (embedNUL) {
5982 		entropy[0] &= ~(0xffull << 8);
5983 	}
5984 
5985 	int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
5986 	size_t remaining = sizeof(str) - len;
5987 	for (int i = 1; i < values && remaining > 0; ++i) {
5988 		size_t start = sizeof(str) - remaining;
5989 		len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
5990 		remaining -= len;
5991 	}
5992 
5993 	return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
5994 }
5995 
5996 /*
5997  * Build up the contents of the apple[] string vector
5998  */
5999 #if (DEVELOPMENT || DEBUG)
6000 extern uint64_t dyld_flags;
6001 #endif
6002 
6003 #if __has_feature(ptrauth_calls)
6004 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)6005 is_arm64e_running_as_arm64(const struct image_params *imgp)
6006 {
6007 	return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
6008 	       (imgp->ip_flags & IMGPF_NOJOP);
6009 }
6010 #endif /* __has_feature(ptrauth_calls) */
6011 
6012 _Atomic uint64_t libmalloc_experiment_factors = 0;
6013 
6014 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result)6015 exec_add_apple_strings(struct image_params *imgp,
6016     const load_result_t *load_result)
6017 {
6018 	int error;
6019 	int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6020 	thread_t new_thread;
6021 	ipc_port_t sright;
6022 	uint64_t local_experiment_factors = 0;
6023 
6024 	/* exec_save_path stored the first string */
6025 	imgp->ip_applec = 1;
6026 
6027 	/* adding the pfz string */
6028 	{
6029 		char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
6030 
6031 		if (img_ptr_size == 8) {
6032 			__assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
6033 			assert(ret < sizeof(pfz_string));
6034 		} else {
6035 			snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
6036 		}
6037 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
6038 		if (error) {
6039 			printf("Failed to add the pfz string with error %d\n", error);
6040 			goto bad;
6041 		}
6042 		imgp->ip_applec++;
6043 	}
6044 
6045 	/* adding the NANO_ENGAGE_KEY key */
6046 	if (imgp->ip_px_sa) {
6047 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6048 		int proc_flags = psa->psa_flags;
6049 
6050 		if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
6051 			const char *nano_string = NANO_ENGAGE_KEY;
6052 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
6053 			if (error) {
6054 				goto bad;
6055 			}
6056 			imgp->ip_applec++;
6057 		}
6058 #if CONFIG_JETSAM && CONFIG_MEMORYSTATUS && CONFIG_DEFERRED_RECLAIM
6059 		if (vm_reclaim_max_threshold > 0) {
6060 			int psa_apptype = psa->psa_apptype;
6061 
6062 			if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) == POSIX_SPAWN_PROC_TYPE_APP_DEFAULT) {
6063 				const char *reclaim_string = RECLAIM_ENGAGE_KEY;
6064 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(reclaim_string), UIO_SYSSPACE, FALSE);
6065 				if (error) {
6066 					goto bad;
6067 				}
6068 				imgp->ip_applec++;
6069 			}
6070 		}
6071 #endif /* CONFIG_JETSAM && CONFIG_MEMORYSTATUS && CONFIG_DEFERRED_RECLAIM */
6072 	}
6073 
6074 	/*
6075 	 * Supply libc with a collection of random values to use when
6076 	 * implementing -fstack-protector.
6077 	 *
6078 	 * (The first random string always contains an embedded NUL so that
6079 	 * __stack_chk_guard also protects against C string vulnerabilities)
6080 	 */
6081 	error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
6082 	if (error) {
6083 		goto bad;
6084 	}
6085 	imgp->ip_applec++;
6086 
6087 	/*
6088 	 * Supply libc with entropy for system malloc.
6089 	 */
6090 	error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
6091 	if (error) {
6092 		goto bad;
6093 	}
6094 	imgp->ip_applec++;
6095 
6096 	/*
6097 	 * Supply libpthread & libplatform with a random value to use for pointer
6098 	 * obfuscation.
6099 	 */
6100 	error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
6101 	if (error) {
6102 		goto bad;
6103 	}
6104 	imgp->ip_applec++;
6105 
6106 	/*
6107 	 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
6108 	 * stack if it was allocated by the kernel.
6109 	 *
6110 	 * The guard page is not included in this stack size as libpthread
6111 	 * expects to add it back in after receiving this value.
6112 	 */
6113 	if (load_result->unixproc) {
6114 		char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
6115 		snprintf(stack_string, sizeof(stack_string),
6116 		    MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
6117 		    (uint64_t)load_result->user_stack,
6118 		    (uint64_t)load_result->user_stack_size,
6119 		    (uint64_t)load_result->user_stack_alloc,
6120 		    (uint64_t)load_result->user_stack_alloc_size);
6121 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
6122 		if (error) {
6123 			goto bad;
6124 		}
6125 		imgp->ip_applec++;
6126 	}
6127 
6128 	if (imgp->ip_vattr) {
6129 		uint64_t fsid    = vnode_get_va_fsid(imgp->ip_vattr);
6130 		uint64_t fsobjid = imgp->ip_vattr->va_fileid;
6131 
6132 		char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6133 		snprintf(fsid_string, sizeof(fsid_string),
6134 		    FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
6135 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6136 		if (error) {
6137 			goto bad;
6138 		}
6139 		imgp->ip_applec++;
6140 	}
6141 
6142 	if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
6143 		char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6144 		snprintf(fsid_string, sizeof(fsid_string),
6145 		    DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
6146 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6147 		if (error) {
6148 			goto bad;
6149 		}
6150 		imgp->ip_applec++;
6151 	}
6152 
6153 	uint8_t cdhash[SHA1_RESULTLEN];
6154 	int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash);
6155 	if (cdhash_errror == 0) {
6156 		char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
6157 		strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
6158 		char *p = hash_string + sizeof(CDHASH_KEY) - 1;
6159 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6160 			snprintf(p, 3, "%02x", (int) cdhash[i]);
6161 			p += 2;
6162 		}
6163 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
6164 		if (error) {
6165 			goto bad;
6166 		}
6167 		imgp->ip_applec++;
6168 
6169 		/* hash together cd-hash and boot-session-uuid */
6170 		uint8_t sha_digest[SHA256_DIGEST_LENGTH];
6171 		SHA256_CTX sha_ctx;
6172 		SHA256_Init(&sha_ctx);
6173 		SHA256_Update(&sha_ctx, &exe_boothash_salt, sizeof(exe_boothash_salt));
6174 		SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
6175 		SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
6176 		SHA256_Final(sha_digest, &sha_ctx);
6177 		char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
6178 		strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
6179 		char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
6180 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6181 			snprintf(s, 3, "%02x", (int) sha_digest[i]);
6182 			s += 2;
6183 		}
6184 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
6185 		if (error) {
6186 			goto bad;
6187 		}
6188 		imgp->ip_applec++;
6189 	}
6190 #if (DEVELOPMENT || DEBUG)
6191 	if (dyld_flags) {
6192 		char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
6193 		snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
6194 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
6195 		if (error) {
6196 			goto bad;
6197 		}
6198 		imgp->ip_applec++;
6199 	}
6200 #endif
6201 	if (imgp->ip_subsystem_root_path) {
6202 		size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
6203 		char subsystem_root_path_string[buffer_len];
6204 		int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
6205 
6206 		if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
6207 			error = ENAMETOOLONG;
6208 			goto bad;
6209 		}
6210 
6211 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
6212 		if (error) {
6213 			goto bad;
6214 		}
6215 
6216 		imgp->ip_applec++;
6217 	}
6218 #if __has_feature(ptrauth_calls)
6219 	if (is_arm64e_running_as_arm64(imgp)) {
6220 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
6221 		if (error) {
6222 			goto bad;
6223 		}
6224 
6225 		imgp->ip_applec++;
6226 	}
6227 #endif /* __has_feature(ptrauth_calls) */
6228 
6229 
6230 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
6231 	{
6232 		char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
6233 		strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
6234 		bool allowAll = bootarg_arm64e_preview_abi;
6235 		strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
6236 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
6237 		if (error) {
6238 			goto bad;
6239 		}
6240 
6241 		imgp->ip_applec++;
6242 	}
6243 #endif
6244 	/*
6245 	 * Add main thread mach port name
6246 	 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
6247 	 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
6248 	 * against libpthread.
6249 	 */
6250 	if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
6251 		thread_reference(new_thread);
6252 		sright = convert_thread_to_port_pinned(new_thread);
6253 		task_t new_task = get_threadtask(new_thread);
6254 		mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
6255 		char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
6256 		snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
6257 
6258 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
6259 		if (error) {
6260 			goto bad;
6261 		}
6262 		imgp->ip_applec++;
6263 	}
6264 
6265 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6266 	if (imgp->ip_px_sa != NULL) {
6267 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6268 		if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
6269 			const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
6270 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
6271 			if (error) {
6272 				goto bad;
6273 			}
6274 			imgp->ip_applec++;
6275 		}
6276 	}
6277 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6278 
6279 	/* adding the libmalloc experiment string */
6280 	local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
6281 	if (__improbable(local_experiment_factors != 0)) {
6282 		char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
6283 
6284 		snprintf(
6285 			libmalloc_experiment_factors_string,
6286 			sizeof(libmalloc_experiment_factors_string),
6287 			LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
6288 			local_experiment_factors);
6289 		error = exec_add_user_string(
6290 			imgp,
6291 			CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
6292 			UIO_SYSSPACE,
6293 			FALSE);
6294 		if (error) {
6295 			printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
6296 			goto bad;
6297 		}
6298 		imgp->ip_applec++;
6299 	}
6300 
6301 	/* tell dyld that it can leverage hardware for its read-only/read-write trusted path */
6302 	if (imgp->ip_flags & IMGPF_HW_TPRO) {
6303 		const char *dyld_hw_tpro = "dyld_hw_tpro=1";
6304 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_hw_tpro), UIO_SYSSPACE, FALSE);
6305 		if (error) {
6306 			printf("Failed to add dyld hw tpro setting with error %d\n", error);
6307 			goto bad;
6308 		}
6309 
6310 		imgp->ip_applec++;
6311 
6312 	}
6313 
6314 	/* Align the tail of the combined applev area */
6315 	while (imgp->ip_strspace % img_ptr_size != 0) {
6316 		*imgp->ip_strendp++ = '\0';
6317 		imgp->ip_strspace--;
6318 	}
6319 
6320 bad:
6321 	return error;
6322 }
6323 
6324 /*
6325  * exec_check_permissions
6326  *
6327  * Description:	Verify that the file that is being attempted to be executed
6328  *		is in fact allowed to be executed based on it POSIX file
6329  *		permissions and other access control criteria
6330  *
6331  * Parameters:	struct image_params *	the image parameter block
6332  *
6333  * Returns:	0			Success
6334  *		EACCES			Permission denied
6335  *		ENOEXEC			Executable file format error
6336  *		ETXTBSY			Text file busy [misuse of error code]
6337  *	vnode_getattr:???
6338  *	vnode_authorize:???
6339  */
6340 static int
exec_check_permissions(struct image_params * imgp)6341 exec_check_permissions(struct image_params *imgp)
6342 {
6343 	struct vnode *vp = imgp->ip_vp;
6344 	struct vnode_attr *vap = imgp->ip_vattr;
6345 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6346 	int error;
6347 	kauth_action_t action;
6348 
6349 	/* Only allow execution of regular files */
6350 	if (!vnode_isreg(vp)) {
6351 		return EACCES;
6352 	}
6353 
6354 	/* Get the file attributes that we will be using here and elsewhere */
6355 	VATTR_INIT(vap);
6356 	VATTR_WANTED(vap, va_uid);
6357 	VATTR_WANTED(vap, va_gid);
6358 	VATTR_WANTED(vap, va_mode);
6359 	VATTR_WANTED(vap, va_fsid);
6360 	VATTR_WANTED(vap, va_fsid64);
6361 	VATTR_WANTED(vap, va_fileid);
6362 	VATTR_WANTED(vap, va_data_size);
6363 	if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
6364 		return error;
6365 	}
6366 
6367 	/*
6368 	 * Ensure that at least one execute bit is on - otherwise root
6369 	 * will always succeed, and we don't want to happen unless the
6370 	 * file really is executable.
6371 	 */
6372 	if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
6373 		return EACCES;
6374 	}
6375 
6376 	/* Disallow zero length files */
6377 	if (vap->va_data_size == 0) {
6378 		return ENOEXEC;
6379 	}
6380 
6381 	imgp->ip_arch_offset = (user_size_t)0;
6382 #if __LP64__
6383 	imgp->ip_arch_size = vap->va_data_size;
6384 #else
6385 	if (vap->va_data_size > UINT32_MAX) {
6386 		return ENOEXEC;
6387 	}
6388 	imgp->ip_arch_size = (user_size_t)vap->va_data_size;
6389 #endif
6390 
6391 	/* Disable setuid-ness for traced programs or if MNT_NOSUID */
6392 	if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
6393 		vap->va_mode &= ~(VSUID | VSGID);
6394 	}
6395 
6396 	/*
6397 	 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
6398 	 * flags for setuid/setgid binaries.
6399 	 */
6400 	if (vap->va_mode & (VSUID | VSGID)) {
6401 		imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
6402 	}
6403 
6404 #if CONFIG_MACF
6405 	error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
6406 	if (error) {
6407 		return error;
6408 	}
6409 #endif
6410 
6411 	/* Check for execute permission */
6412 	action = KAUTH_VNODE_EXECUTE;
6413 	/* Traced images must also be readable */
6414 	if (p->p_lflag & P_LTRACED) {
6415 		action |= KAUTH_VNODE_READ_DATA;
6416 	}
6417 	if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
6418 		return error;
6419 	}
6420 
6421 #if 0
6422 	/* Don't let it run if anyone had it open for writing */
6423 	vnode_lock(vp);
6424 	if (vp->v_writecount) {
6425 		panic("going to return ETXTBSY %x", vp);
6426 		vnode_unlock(vp);
6427 		return ETXTBSY;
6428 	}
6429 	vnode_unlock(vp);
6430 #endif
6431 
6432 	/* XXX May want to indicate to underlying FS that vnode is open */
6433 
6434 	return error;
6435 }
6436 
6437 
6438 /*
6439  * exec_handle_sugid
6440  *
6441  * Initially clear the P_SUGID in the process flags; if an SUGID process is
6442  * exec'ing a non-SUGID image, then  this is the point of no return.
6443  *
6444  * If the image being activated is SUGID, then replace the credential with a
6445  * copy, disable tracing (unless the tracing process is root), reset the
6446  * mach task port to revoke it, set the P_SUGID bit,
6447  *
6448  * If the saved user and group ID will be changing, then make sure it happens
6449  * to a new credential, rather than a shared one.
6450  *
6451  * Set the security token (this is probably obsolete, given that the token
6452  * should not technically be separate from the credential itself).
6453  *
6454  * Parameters:	struct image_params *	the image parameter block
6455  *
6456  * Returns:	void			No failure indication
6457  *
6458  * Implicit returns:
6459  *		<process credential>	Potentially modified/replaced
6460  *		<task port>		Potentially revoked
6461  *		<process flags>		P_SUGID bit potentially modified
6462  *		<security token>	Potentially modified
6463  */
6464 __attribute__((noinline))
6465 static int
exec_handle_sugid(struct image_params * imgp)6466 exec_handle_sugid(struct image_params *imgp)
6467 {
6468 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
6469 	kauth_cred_t            cred = vfs_context_ucred(imgp->ip_vfs_context);
6470 	int                     i;
6471 	int                     leave_sugid_clear = 0;
6472 	int                     mac_reset_ipc = 0;
6473 	int                     error = 0;
6474 #if CONFIG_MACF
6475 	int                     mac_transition, disjoint_cred = 0;
6476 	int             label_update_return = 0;
6477 
6478 	/*
6479 	 * Determine whether a call to update the MAC label will result in the
6480 	 * credential changing.
6481 	 *
6482 	 * Note:	MAC policies which do not actually end up modifying
6483 	 *		the label subsequently are strongly encouraged to
6484 	 *		return 0 for this check, since a non-zero answer will
6485 	 *		slow down the exec fast path for normal binaries.
6486 	 */
6487 	mac_transition = mac_cred_check_label_update_execve(
6488 		imgp->ip_vfs_context,
6489 		imgp->ip_vp,
6490 		imgp->ip_arch_offset,
6491 		imgp->ip_scriptvp,
6492 		imgp->ip_scriptlabelp,
6493 		imgp->ip_execlabelp,
6494 		p,
6495 		&imgp->ip_px_smpx);
6496 #endif
6497 
6498 	OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
6499 
6500 	/*
6501 	 * Order of the following is important; group checks must go last,
6502 	 * as we use the success of the 'ismember' check combined with the
6503 	 * failure of the explicit match to indicate that we will be setting
6504 	 * the egid of the process even though the new process did not
6505 	 * require VSUID/VSGID bits in order for it to set the new group as
6506 	 * its egid.
6507 	 *
6508 	 * Note:	Technically, by this we are implying a call to
6509 	 *		setegid() in the new process, rather than implying
6510 	 *		it used its VSGID bit to set the effective group,
6511 	 *		even though there is no code in that process to make
6512 	 *		such a call.
6513 	 */
6514 	if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
6515 	    kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
6516 	    ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
6517 	    ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
6518 	    (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
6519 #if CONFIG_MACF
6520 /* label for MAC transition and neither VSUID nor VSGID */
6521 handle_mac_transition:
6522 #endif
6523 
6524 #if CONFIG_SETUID
6525 		/*
6526 		 * Replace the credential with a copy of itself if euid or
6527 		 * egid change.
6528 		 *
6529 		 * Note:	setuid binaries will automatically opt out of
6530 		 *		group resolver participation as a side effect
6531 		 *		of this operation.  This is an intentional
6532 		 *		part of the security model, which requires a
6533 		 *		participating credential be established by
6534 		 *		escalating privilege, setting up all other
6535 		 *		aspects of the credential including whether
6536 		 *		or not to participate in external group
6537 		 *		membership resolution, then dropping their
6538 		 *		effective privilege to that of the desired
6539 		 *		final credential state.
6540 		 *
6541 		 * Modifications to p_ucred must be guarded using the
6542 		 * proc's ucred lock. This prevents others from accessing
6543 		 * a garbage credential.
6544 		 */
6545 
6546 		if (imgp->ip_origvattr->va_mode & VSUID) {
6547 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6548 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6549 				return kauth_cred_model_setresuid(model,
6550 				KAUTH_UID_NONE,
6551 				imgp->ip_origvattr->va_uid,
6552 				imgp->ip_origvattr->va_uid,
6553 				KAUTH_UID_NONE);
6554 			});
6555 		}
6556 
6557 		if (imgp->ip_origvattr->va_mode & VSGID) {
6558 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6559 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6560 				return kauth_cred_model_setresgid(model,
6561 				KAUTH_GID_NONE,
6562 				imgp->ip_origvattr->va_gid,
6563 				imgp->ip_origvattr->va_gid);
6564 			});
6565 		}
6566 #endif /* CONFIG_SETUID */
6567 
6568 #if CONFIG_MACF
6569 		/*
6570 		 * If a policy has indicated that it will transition the label,
6571 		 * before making the call into the MAC policies, get a new
6572 		 * duplicate credential, so they can modify it without
6573 		 * modifying any others sharing it.
6574 		 */
6575 		if (mac_transition) {
6576 			/*
6577 			 * This hook may generate upcalls that require
6578 			 * importance donation from the kernel.
6579 			 * (23925818)
6580 			 */
6581 			thread_t thread = current_thread();
6582 			thread_enable_send_importance(thread, TRUE);
6583 			kauth_proc_label_update_execve(p,
6584 			    imgp->ip_vfs_context,
6585 			    imgp->ip_vp,
6586 			    imgp->ip_arch_offset,
6587 			    imgp->ip_scriptvp,
6588 			    imgp->ip_scriptlabelp,
6589 			    imgp->ip_execlabelp,
6590 			    &imgp->ip_csflags,
6591 			    &imgp->ip_px_smpx,
6592 			    &disjoint_cred,                     /* will be non zero if disjoint */
6593 			    &label_update_return);
6594 			thread_enable_send_importance(thread, FALSE);
6595 
6596 			if (disjoint_cred) {
6597 				/*
6598 				 * If updating the MAC label resulted in a
6599 				 * disjoint credential, flag that we need to
6600 				 * set the P_SUGID bit.  This protects
6601 				 * against debuggers being attached by an
6602 				 * insufficiently privileged process onto the
6603 				 * result of a transition to a more privileged
6604 				 * credential.
6605 				 */
6606 				leave_sugid_clear = 0;
6607 			}
6608 
6609 			imgp->ip_mac_return = label_update_return;
6610 		}
6611 
6612 		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);
6613 
6614 #endif  /* CONFIG_MACF */
6615 
6616 		/*
6617 		 * If 'leave_sugid_clear' is non-zero, then we passed the
6618 		 * VSUID and MACF checks, and successfully determined that
6619 		 * the previous cred was a member of the VSGID group, but
6620 		 * that it was not the default at the time of the execve,
6621 		 * and that the post-labelling credential was not disjoint.
6622 		 * So we don't set the P_SUGID or reset mach ports and fds
6623 		 * on the basis of simply running this code.
6624 		 */
6625 		if (mac_reset_ipc || !leave_sugid_clear) {
6626 			/*
6627 			 * Have mach reset the task and thread ports.
6628 			 * We don't want anyone who had the ports before
6629 			 * a setuid exec to be able to access/control the
6630 			 * task/thread after.
6631 			 */
6632 			ipc_task_reset((imgp->ip_new_thread != NULL) ?
6633 			    get_threadtask(imgp->ip_new_thread) : proc_task(p));
6634 			ipc_thread_reset((imgp->ip_new_thread != NULL) ?
6635 			    imgp->ip_new_thread : current_thread());
6636 		}
6637 
6638 		if (!leave_sugid_clear) {
6639 			/*
6640 			 * Flag the process as setuid.
6641 			 */
6642 			OSBitOrAtomic(P_SUGID, &p->p_flag);
6643 
6644 			/*
6645 			 * Radar 2261856; setuid security hole fix
6646 			 * XXX For setuid processes, attempt to ensure that
6647 			 * stdin, stdout, and stderr are already allocated.
6648 			 * We do not want userland to accidentally allocate
6649 			 * descriptors in this range which has implied meaning
6650 			 * to libc.
6651 			 */
6652 			for (i = 0; i < 3; i++) {
6653 				if (fp_get_noref_locked(p, i) != NULL) {
6654 					continue;
6655 				}
6656 
6657 				/*
6658 				 * Do the kernel equivalent of
6659 				 *
6660 				 *      if i == 0
6661 				 *              (void) open("/dev/null", O_RDONLY);
6662 				 *      else
6663 				 *              (void) open("/dev/null", O_WRONLY);
6664 				 */
6665 
6666 				struct fileproc *fp;
6667 				int indx;
6668 				int flag;
6669 				struct nameidata *ndp = NULL;
6670 
6671 				if (i == 0) {
6672 					flag = FREAD;
6673 				} else {
6674 					flag = FWRITE;
6675 				}
6676 
6677 				if ((error = falloc(p,
6678 				    &fp, &indx, imgp->ip_vfs_context)) != 0) {
6679 					continue;
6680 				}
6681 
6682 				ndp = kalloc_type(struct nameidata,
6683 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
6684 
6685 				NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
6686 				    CAST_USER_ADDR_T("/dev/null"),
6687 				    imgp->ip_vfs_context);
6688 
6689 				if ((error = vn_open(ndp, flag, 0)) != 0) {
6690 					fp_free(p, indx, fp);
6691 					kfree_type(struct nameidata, ndp);
6692 					break;
6693 				}
6694 
6695 				struct fileglob *fg = fp->fp_glob;
6696 
6697 				fg->fg_flag = flag;
6698 				fg->fg_ops = &vnops;
6699 				fp_set_data(fp, ndp->ni_vp);
6700 
6701 				vnode_put(ndp->ni_vp);
6702 
6703 				proc_fdlock(p);
6704 				procfdtbl_releasefd(p, indx, NULL);
6705 				fp_drop(p, indx, fp, 1);
6706 				proc_fdunlock(p);
6707 
6708 				kfree_type(struct nameidata, ndp);
6709 			}
6710 		}
6711 	}
6712 #if CONFIG_MACF
6713 	else {
6714 		/*
6715 		 * We are here because we were told that the MAC label will
6716 		 * be transitioned, and the binary is not VSUID or VSGID; to
6717 		 * deal with this case, we could either duplicate a lot of
6718 		 * code, or we can indicate we want to default the P_SUGID
6719 		 * bit clear and jump back up.
6720 		 */
6721 		if (mac_transition) {
6722 			leave_sugid_clear = 1;
6723 			goto handle_mac_transition;
6724 		}
6725 	}
6726 
6727 #endif  /* CONFIG_MACF */
6728 
6729 	/* Update the process' identity version and set the security token */
6730 	proc_setpidversion(p, OSIncrementAtomic(&nextpidversion));
6731 	task_set_uniqueid(proc_task(p));
6732 
6733 	/*
6734 	 * Implement the semantic where the effective user and group become
6735 	 * the saved user and group in exec'ed programs.
6736 	 */
6737 	kauth_cred_proc_update(p, PROC_SETTOKEN_ALWAYS,
6738 	    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6739 		posix_cred_t pcred = posix_cred_get(model);
6740 
6741 		if (pcred->cr_svuid == pcred->cr_uid &&
6742 		pcred->cr_svgid == pcred->cr_gid) {
6743 		        return false;
6744 		}
6745 
6746 		pcred->cr_svuid = pcred->cr_uid;
6747 		pcred->cr_svgid = pcred->cr_gid;
6748 		return true;
6749 	});
6750 
6751 	return error;
6752 }
6753 
6754 
6755 /*
6756  * create_unix_stack
6757  *
6758  * Description:	Set the user stack address for the process to the provided
6759  *		address.  If a custom stack was not set as a result of the
6760  *		load process (i.e. as specified by the image file for the
6761  *		executable), then allocate the stack in the provided map and
6762  *		set up appropriate guard pages for enforcing administrative
6763  *		limits on stack growth, if they end up being needed.
6764  *
6765  * Parameters:	p			Process to set stack on
6766  *		load_result		Information from mach-o load commands
6767  *		map			Address map in which to allocate the new stack
6768  *
6769  * Returns:	KERN_SUCCESS		Stack successfully created
6770  *		!KERN_SUCCESS		Mach failure code
6771  */
6772 __attribute__((noinline))
6773 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)6774 create_unix_stack(vm_map_t map, load_result_t* load_result,
6775     proc_t p)
6776 {
6777 	mach_vm_size_t          size, prot_size;
6778 	mach_vm_offset_t        addr, prot_addr;
6779 	kern_return_t           kr;
6780 
6781 	mach_vm_address_t       user_stack = load_result->user_stack;
6782 
6783 	proc_lock(p);
6784 	p->user_stack = (uintptr_t)user_stack;
6785 	if (load_result->custom_stack) {
6786 		p->p_lflag |= P_LCUSTOM_STACK;
6787 	}
6788 	proc_unlock(p);
6789 	if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
6790 		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);
6791 	}
6792 
6793 	if (load_result->user_stack_alloc_size > 0) {
6794 		/*
6795 		 * Allocate enough space for the maximum stack size we
6796 		 * will ever authorize and an extra page to act as
6797 		 * a guard page for stack overflows. For default stacks,
6798 		 * vm_initial_limit_stack takes care of the extra guard page.
6799 		 * Otherwise we must allocate it ourselves.
6800 		 */
6801 		if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
6802 			return KERN_INVALID_ARGUMENT;
6803 		}
6804 		addr = vm_map_trunc_page(load_result->user_stack - size,
6805 		    vm_map_page_mask(map));
6806 		kr = mach_vm_allocate_kernel(map, &addr, size,
6807 		    VM_FLAGS_FIXED, VM_MEMORY_STACK);
6808 		if (kr != KERN_SUCCESS) {
6809 			// Can't allocate at default location, try anywhere
6810 			addr = 0;
6811 			kr = mach_vm_allocate_kernel(map, &addr, size,
6812 			    VM_FLAGS_ANYWHERE, VM_MEMORY_STACK);
6813 			if (kr != KERN_SUCCESS) {
6814 				return kr;
6815 			}
6816 
6817 			user_stack = addr + size;
6818 			load_result->user_stack = (user_addr_t)user_stack;
6819 
6820 			proc_lock(p);
6821 			p->user_stack = (uintptr_t)user_stack;
6822 			proc_unlock(p);
6823 		}
6824 
6825 		load_result->user_stack_alloc = (user_addr_t)addr;
6826 
6827 		/*
6828 		 * And prevent access to what's above the current stack
6829 		 * size limit for this process.
6830 		 */
6831 		if (load_result->user_stack_size == 0) {
6832 			load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
6833 			prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
6834 		} else {
6835 			prot_size = PAGE_SIZE;
6836 		}
6837 
6838 		prot_addr = addr;
6839 		kr = mach_vm_protect(map,
6840 		    prot_addr,
6841 		    prot_size,
6842 		    FALSE,
6843 		    VM_PROT_NONE);
6844 		if (kr != KERN_SUCCESS) {
6845 			(void)mach_vm_deallocate(map, addr, size);
6846 			return kr;
6847 		}
6848 	}
6849 
6850 	return KERN_SUCCESS;
6851 }
6852 
6853 #include <sys/reboot.h>
6854 
6855 /*
6856  * load_init_program_at_path
6857  *
6858  * Description:	Load the "init" program; in most cases, this will be "launchd"
6859  *
6860  * Parameters:	p			Process to call execve() to create
6861  *					the "init" program
6862  *		scratch_addr		Page in p, scratch space
6863  *		path			NULL terminated path
6864  *
6865  * Returns:	KERN_SUCCESS		Success
6866  *		!KERN_SUCCESS           See execve/mac_execve for error codes
6867  *
6868  * Notes:	The process that is passed in is the first manufactured
6869  *		process on the system, and gets here via bsd_ast() firing
6870  *		for the first time.  This is done to ensure that bsd_init()
6871  *		has run to completion.
6872  *
6873  *		The address map of the first manufactured process matches the
6874  *		word width of the kernel. Once the self-exec completes, the
6875  *		initproc might be different.
6876  */
6877 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)6878 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
6879 {
6880 	int retval[2];
6881 	int error;
6882 	struct execve_args init_exec_args;
6883 	user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
6884 
6885 	/*
6886 	 * Validate inputs and pre-conditions
6887 	 */
6888 	assert(p);
6889 	assert(scratch_addr);
6890 	assert(path);
6891 
6892 	/*
6893 	 * Copy out program name.
6894 	 */
6895 	size_t path_length = strlen(path) + 1;
6896 	argv0 = scratch_addr;
6897 	error = copyout(path, argv0, path_length);
6898 	if (error) {
6899 		return error;
6900 	}
6901 
6902 	scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
6903 
6904 	/*
6905 	 * Put out first (and only) argument, similarly.
6906 	 * Assumes everything fits in a page as allocated above.
6907 	 */
6908 	if (boothowto & RB_SINGLE) {
6909 		const char *init_args = "-s";
6910 		size_t init_args_length = strlen(init_args) + 1;
6911 
6912 		argv1 = scratch_addr;
6913 		error = copyout(init_args, argv1, init_args_length);
6914 		if (error) {
6915 			return error;
6916 		}
6917 
6918 		scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
6919 	}
6920 
6921 	if (proc_is64bit(p)) {
6922 		user64_addr_t argv64bit[3] = {};
6923 
6924 		argv64bit[0] = argv0;
6925 		argv64bit[1] = argv1;
6926 		argv64bit[2] = USER_ADDR_NULL;
6927 
6928 		error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
6929 		if (error) {
6930 			return error;
6931 		}
6932 	} else {
6933 		user32_addr_t argv32bit[3] = {};
6934 
6935 		argv32bit[0] = (user32_addr_t)argv0;
6936 		argv32bit[1] = (user32_addr_t)argv1;
6937 		argv32bit[2] = USER_ADDR_NULL;
6938 
6939 		error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
6940 		if (error) {
6941 			return error;
6942 		}
6943 	}
6944 
6945 	/*
6946 	 * Set up argument block for fake call to execve.
6947 	 */
6948 	init_exec_args.fname = argv0;
6949 	init_exec_args.argp = scratch_addr;
6950 	init_exec_args.envp = USER_ADDR_NULL;
6951 
6952 	/*
6953 	 * So that init task is set with uid,gid 0 token
6954 	 *
6955 	 * The access to the cred is safe:
6956 	 * the proc isn't running yet, it's stable.
6957 	 */
6958 	set_security_token(p, proc_ucred_unsafe(p));
6959 
6960 	return execve(p, &init_exec_args, retval);
6961 }
6962 
6963 static const char * init_programs[] = {
6964 #if DEBUG
6965 	"/usr/appleinternal/sbin/launchd.debug",
6966 #endif
6967 #if DEVELOPMENT || DEBUG
6968 	"/usr/appleinternal/sbin/launchd.development",
6969 #endif
6970 	"/sbin/launchd",
6971 };
6972 
6973 /*
6974  * load_init_program
6975  *
6976  * Description:	Load the "init" program; in most cases, this will be "launchd"
6977  *
6978  * Parameters:	p			Process to call execve() to create
6979  *					the "init" program
6980  *
6981  * Returns:	(void)
6982  *
6983  * Notes:	The process that is passed in is the first manufactured
6984  *		process on the system, and gets here via bsd_ast() firing
6985  *		for the first time.  This is done to ensure that bsd_init()
6986  *		has run to completion.
6987  *
6988  *		In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
6989  *		may be used to select a specific launchd executable. As with
6990  *		the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
6991  *		will force /sbin/launchd to be selected.
6992  *
6993  *              Search order by build:
6994  *
6995  * DEBUG	DEVELOPMENT	RELEASE		PATH
6996  * ----------------------------------------------------------------------------------
6997  * 1		1		NA		/usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
6998  * 2		NA		NA		/usr/appleinternal/sbin/launchd.debug
6999  * 3		2		NA		/usr/appleinternal/sbin/launchd.development
7000  * 4		3		1		/sbin/launchd
7001  */
7002 void
load_init_program(proc_t p)7003 load_init_program(proc_t p)
7004 {
7005 	uint32_t i;
7006 	int error;
7007 	vm_map_t map = current_map();
7008 	mach_vm_offset_t scratch_addr = 0;
7009 	mach_vm_size_t map_page_size = vm_map_page_size(map);
7010 
7011 	(void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size, VM_FLAGS_ANYWHERE, VM_KERN_MEMORY_NONE);
7012 #if CONFIG_MEMORYSTATUS
7013 	(void) memorystatus_init_at_boot_snapshot();
7014 #endif /* CONFIG_MEMORYSTATUS */
7015 
7016 #if DEBUG || DEVELOPMENT
7017 	/* Check for boot-arg suffix first */
7018 	char launchd_suffix[64];
7019 	if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
7020 		char launchd_path[128];
7021 		boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
7022 		    (strcmp(launchd_suffix, "release") == 0));
7023 
7024 		if (is_release_suffix) {
7025 			printf("load_init_program: attempting to load /sbin/launchd\n");
7026 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
7027 			if (!error) {
7028 				return;
7029 			}
7030 
7031 			panic("Process 1 exec of launchd.release failed, errno %d", error);
7032 		} else {
7033 			strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
7034 			strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
7035 
7036 			printf("load_init_program: attempting to load %s\n", launchd_path);
7037 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
7038 			if (!error) {
7039 				return;
7040 			} else if (error != ENOENT) {
7041 				printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
7042 			}
7043 		}
7044 	}
7045 #endif
7046 
7047 	error = ENOENT;
7048 	for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
7049 		printf("load_init_program: attempting to load %s\n", init_programs[i]);
7050 		error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
7051 		if (!error) {
7052 			return;
7053 		} else if (error != ENOENT) {
7054 			printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
7055 		}
7056 	}
7057 
7058 	panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
7059 }
7060 
7061 /*
7062  * load_return_to_errno
7063  *
7064  * Description:	Convert a load_return_t (Mach error) to an errno (BSD error)
7065  *
7066  * Parameters:	lrtn			Mach error number
7067  *
7068  * Returns:	(int)			BSD error number
7069  *		0			Success
7070  *		EBADARCH		Bad architecture
7071  *		EBADMACHO		Bad Mach object file
7072  *		ESHLIBVERS		Bad shared library version
7073  *		ENOMEM			Out of memory/resource shortage
7074  *		EACCES			Access denied
7075  *		ENOENT			Entry not found (usually "file does
7076  *					does not exist")
7077  *		EIO			An I/O error occurred
7078  *		EBADEXEC		The executable is corrupt/unknown
7079  */
7080 static int
load_return_to_errno(load_return_t lrtn)7081 load_return_to_errno(load_return_t lrtn)
7082 {
7083 	switch (lrtn) {
7084 	case LOAD_SUCCESS:
7085 		return 0;
7086 	case LOAD_BADARCH:
7087 		return EBADARCH;
7088 	case LOAD_BADMACHO:
7089 	case LOAD_BADMACHO_UPX:
7090 		return EBADMACHO;
7091 	case LOAD_SHLIB:
7092 		return ESHLIBVERS;
7093 	case LOAD_NOSPACE:
7094 	case LOAD_RESOURCE:
7095 		return ENOMEM;
7096 	case LOAD_PROTECT:
7097 		return EACCES;
7098 	case LOAD_ENOENT:
7099 		return ENOENT;
7100 	case LOAD_IOERROR:
7101 		return EIO;
7102 	case LOAD_DECRYPTFAIL:
7103 		return EAUTH;
7104 	case LOAD_FAILURE:
7105 	default:
7106 		return EBADEXEC;
7107 	}
7108 }
7109 
7110 #include <mach/mach_types.h>
7111 #include <mach/vm_prot.h>
7112 #include <mach/semaphore.h>
7113 #include <mach/sync_policy.h>
7114 #include <kern/clock.h>
7115 #include <mach/kern_return.h>
7116 
7117 /*
7118  * execargs_alloc
7119  *
7120  * Description:	Allocate the block of memory used by the execve arguments.
7121  *		At the same time, we allocate a page so that we can read in
7122  *		the first page of the image.
7123  *
7124  * Parameters:	struct image_params *	the image parameter block
7125  *
7126  * Returns:	0			Success
7127  *		EINVAL			Invalid argument
7128  *		EACCES			Permission denied
7129  *		EINTR			Interrupted function
7130  *		ENOMEM			Not enough space
7131  *
7132  * Notes:	This is a temporary allocation into the kernel address space
7133  *		to enable us to copy arguments in from user space.  This is
7134  *		necessitated by not mapping the process calling execve() into
7135  *		the kernel address space during the execve() system call.
7136  *
7137  *		We assemble the argument and environment, etc., into this
7138  *		region before copying it as a single block into the child
7139  *		process address space (at the top or bottom of the stack,
7140  *		depending on which way the stack grows; see the function
7141  *		exec_copyout_strings() for details).
7142  *
7143  *		This ends up with a second (possibly unnecessary) copy compared
7144  *		with assembing the data directly into the child address space,
7145  *		instead, but since we cannot be guaranteed that the parent has
7146  *		not modified its environment, we can't really know that it's
7147  *		really a block there as well.
7148  */
7149 
7150 
7151 static int execargs_waiters = 0;
7152 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
7153 
7154 static void
execargs_lock_lock(void)7155 execargs_lock_lock(void)
7156 {
7157 	lck_mtx_lock_spin(&execargs_cache_lock);
7158 }
7159 
7160 static void
execargs_lock_unlock(void)7161 execargs_lock_unlock(void)
7162 {
7163 	lck_mtx_unlock(&execargs_cache_lock);
7164 }
7165 
7166 static wait_result_t
execargs_lock_sleep(void)7167 execargs_lock_sleep(void)
7168 {
7169 	return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
7170 }
7171 
7172 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)7173 execargs_purgeable_allocate(char **execarg_address)
7174 {
7175 	mach_vm_offset_t addr = 0;
7176 	kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
7177 	    BSD_PAGEABLE_SIZE_PER_EXEC, VM_FLAGS_ANYWHERE | VM_FLAGS_PURGABLE,
7178 	    VM_KERN_MEMORY_NONE);
7179 	*execarg_address = (char *)addr;
7180 	assert(kr == KERN_SUCCESS);
7181 	return kr;
7182 }
7183 
7184 static kern_return_t
execargs_purgeable_reference(void * execarg_address)7185 execargs_purgeable_reference(void *execarg_address)
7186 {
7187 	int state = VM_PURGABLE_NONVOLATILE;
7188 	kern_return_t kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7189 
7190 	assert(kr == KERN_SUCCESS);
7191 	return kr;
7192 }
7193 
7194 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)7195 execargs_purgeable_volatilize(void *execarg_address)
7196 {
7197 	int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
7198 	kern_return_t kr;
7199 	kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7200 
7201 	assert(kr == KERN_SUCCESS);
7202 
7203 	return kr;
7204 }
7205 
7206 static void
execargs_wakeup_waiters(void)7207 execargs_wakeup_waiters(void)
7208 {
7209 	thread_wakeup(&execargs_free_count);
7210 }
7211 
7212 static int
execargs_alloc(struct image_params * imgp)7213 execargs_alloc(struct image_params *imgp)
7214 {
7215 	kern_return_t kret;
7216 	wait_result_t res;
7217 	int i, cache_index = -1;
7218 
7219 	execargs_lock_lock();
7220 
7221 	while (execargs_free_count == 0) {
7222 		execargs_waiters++;
7223 		res = execargs_lock_sleep();
7224 		execargs_waiters--;
7225 		if (res != THREAD_AWAKENED) {
7226 			execargs_lock_unlock();
7227 			return EINTR;
7228 		}
7229 	}
7230 
7231 	execargs_free_count--;
7232 
7233 	for (i = 0; i < execargs_cache_size; i++) {
7234 		vm_offset_t element = execargs_cache[i];
7235 		if (element) {
7236 			cache_index = i;
7237 			imgp->ip_strings = (char *)(execargs_cache[i]);
7238 			execargs_cache[i] = 0;
7239 			break;
7240 		}
7241 	}
7242 
7243 	assert(execargs_free_count >= 0);
7244 
7245 	execargs_lock_unlock();
7246 
7247 	if (cache_index == -1) {
7248 		kret = execargs_purgeable_allocate(&imgp->ip_strings);
7249 	} else {
7250 		kret = execargs_purgeable_reference(imgp->ip_strings);
7251 	}
7252 
7253 	assert(kret == KERN_SUCCESS);
7254 	if (kret != KERN_SUCCESS) {
7255 		return ENOMEM;
7256 	}
7257 
7258 	/* last page used to read in file headers */
7259 	imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
7260 	imgp->ip_strendp = imgp->ip_strings;
7261 	imgp->ip_argspace = NCARGS;
7262 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
7263 
7264 	return 0;
7265 }
7266 
7267 /*
7268  * execargs_free
7269  *
7270  * Description:	Free the block of memory used by the execve arguments and the
7271  *		first page of the executable by a previous call to the function
7272  *		execargs_alloc().
7273  *
7274  * Parameters:	struct image_params *	the image parameter block
7275  *
7276  * Returns:	0			Success
7277  *		EINVAL			Invalid argument
7278  *		EINTR			Oeration interrupted
7279  */
7280 static int
execargs_free(struct image_params * imgp)7281 execargs_free(struct image_params *imgp)
7282 {
7283 	kern_return_t kret;
7284 	int i;
7285 	boolean_t needs_wakeup = FALSE;
7286 
7287 	kret = execargs_purgeable_volatilize(imgp->ip_strings);
7288 
7289 	execargs_lock_lock();
7290 	execargs_free_count++;
7291 
7292 	for (i = 0; i < execargs_cache_size; i++) {
7293 		vm_offset_t element = execargs_cache[i];
7294 		if (element == 0) {
7295 			execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
7296 			imgp->ip_strings = NULL;
7297 			break;
7298 		}
7299 	}
7300 
7301 	assert(imgp->ip_strings == NULL);
7302 
7303 	if (execargs_waiters > 0) {
7304 		needs_wakeup = TRUE;
7305 	}
7306 
7307 	execargs_lock_unlock();
7308 
7309 	if (needs_wakeup == TRUE) {
7310 		execargs_wakeup_waiters();
7311 	}
7312 
7313 	return kret == KERN_SUCCESS ? 0 : EINVAL;
7314 }
7315 
7316 void
uthread_set_exec_data(struct uthread * uth,struct image_params * imgp)7317 uthread_set_exec_data(struct uthread *uth, struct image_params *imgp)
7318 {
7319 	uth->uu_save.uus_exec_data.imgp = imgp;
7320 }
7321 
7322 size_t
thread_get_current_exec_path(char * path,size_t size)7323 thread_get_current_exec_path(char *path, size_t size)
7324 {
7325 	struct uthread *uth = current_uthread();
7326 	struct image_params *imgp = uth->uu_save.uus_exec_data.imgp;
7327 	size_t string_size = 0;
7328 	char *exec_path;
7329 
7330 	if (path == NULL || imgp == NULL || imgp->ip_strings == NULL) {
7331 		return 0;
7332 	}
7333 
7334 	exec_path = imgp->ip_strings + strlen(EXECUTABLE_KEY);
7335 	string_size = imgp->ip_strendp - exec_path;
7336 	string_size = MIN(MAXPATHLEN, string_size);
7337 	string_size = MIN(size, string_size);
7338 
7339 	string_size = strlcpy(path, exec_path, string_size);
7340 	return string_size;
7341 }
7342 static void
exec_resettextvp(proc_t p,struct image_params * imgp)7343 exec_resettextvp(proc_t p, struct image_params *imgp)
7344 {
7345 	vnode_t vp;
7346 	off_t offset;
7347 	vnode_t tvp  = p->p_textvp;
7348 	int ret;
7349 
7350 	vp = imgp->ip_vp;
7351 	offset = imgp->ip_arch_offset;
7352 
7353 	if (vp == NULLVP) {
7354 		panic("exec_resettextvp: expected valid vp");
7355 	}
7356 
7357 	ret = vnode_ref(vp);
7358 	proc_lock(p);
7359 	if (ret == 0) {
7360 		p->p_textvp = vp;
7361 		p->p_textoff = offset;
7362 	} else {
7363 		p->p_textvp = NULLVP;   /* this is paranoia */
7364 		p->p_textoff = 0;
7365 	}
7366 	proc_unlock(p);
7367 
7368 	if (tvp != NULLVP) {
7369 		if (vnode_getwithref(tvp) == 0) {
7370 			vnode_rele(tvp);
7371 			vnode_put(tvp);
7372 		}
7373 	}
7374 }
7375 
7376 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
7377 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
7378 
7379 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)7380 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
7381 {
7382 	static char const nibble[] = "0123456789abcdef";
7383 
7384 	/* Apparently still the safest way to get a hex representation
7385 	 * of binary data.
7386 	 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
7387 	 * <rdar://problem/33328859> confusion around %*D/%nD in printf
7388 	 */
7389 	for (int i = 0; i < CS_CDHASH_LEN; ++i) {
7390 		str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
7391 		str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
7392 	}
7393 	str[CS_CDHASH_STRING_SIZE - 1] = 0;
7394 }
7395 
7396 /*
7397  * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
7398  *
7399  * Description: Waits for the userspace daemon to respond to the request
7400  *              we made. Function declared non inline to be visible in
7401  *		stackshots and spindumps as well as debugging.
7402  */
7403 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)7404 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
7405 {
7406 	return find_code_signature(task_access_port, new_pid);
7407 }
7408 
7409 /*
7410  * Update signature dependent process state, called by
7411  * process_signature.
7412  */
7413 static int
proc_process_signature(proc_t p,os_reason_t * signature_failure_reason)7414 proc_process_signature(proc_t p, os_reason_t *signature_failure_reason)
7415 {
7416 	int error = 0;
7417 	char const *error_msg = NULL;
7418 
7419 	kern_return_t kr = machine_task_process_signature(proc_get_task_raw(p), proc_platform(p), proc_sdk(p), &error_msg);
7420 
7421 	if (kr != KERN_SUCCESS) {
7422 		error = EINVAL;
7423 
7424 		if (error_msg != NULL) {
7425 			uint32_t error_msg_len = (uint32_t)strlen(error_msg) + 1;
7426 			mach_vm_address_t data_addr = 0;
7427 			int reason_error = 0;
7428 			int kcdata_error = 0;
7429 
7430 			os_reason_t reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7431 			reason->osr_flags = OS_REASON_FLAG_GENERATE_CRASH_REPORT | OS_REASON_FLAG_CONSISTENT_FAILURE;
7432 
7433 			if ((reason_error = os_reason_alloc_buffer_noblock(reason,
7434 			    kcdata_estimate_required_buffer_size(1, error_msg_len))) == 0 &&
7435 			    (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
7436 			    EXIT_REASON_USER_DESC, error_msg_len,
7437 			    &data_addr)) == KERN_SUCCESS) {
7438 				kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
7439 				    error_msg, error_msg_len);
7440 
7441 				if (mc_error != KERN_SUCCESS) {
7442 					printf("process_signature: failed to copy reason string (kcdata_memcpy error: %d)\n",
7443 					    mc_error);
7444 				}
7445 			} else {
7446 				printf("failed to allocate space for reason string (os_reason_alloc_buffer error: %d, kcdata error: %d, length: %u)\n",
7447 				    reason_error, kcdata_error, error_msg_len);
7448 			}
7449 
7450 			assert(*signature_failure_reason == NULL); // shouldn't have gotten so far
7451 			*signature_failure_reason = reason;
7452 		}
7453 	}
7454 	return error;
7455 }
7456 
7457 static int
process_signature(proc_t p,struct image_params * imgp)7458 process_signature(proc_t p, struct image_params *imgp)
7459 {
7460 	mach_port_t port = IPC_PORT_NULL;
7461 	kern_return_t kr = KERN_FAILURE;
7462 	int error = EACCES;
7463 	boolean_t unexpected_failure = FALSE;
7464 	struct cs_blob *csb;
7465 	boolean_t require_success = FALSE;
7466 	int spawn = (imgp->ip_flags & IMGPF_SPAWN);
7467 	const int vfexec = 0;
7468 	os_reason_t signature_failure_reason = OS_REASON_NULL;
7469 
7470 	/*
7471 	 * Override inherited code signing flags with the
7472 	 * ones for the process that is being successfully
7473 	 * loaded
7474 	 */
7475 	proc_lock(p);
7476 	proc_csflags_update(p, imgp->ip_csflags);
7477 	proc_unlock(p);
7478 
7479 	/* Set the switch_protect flag on the map */
7480 	if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
7481 		vm_map_switch_protect(get_task_map(proc_task(p)), TRUE);
7482 	}
7483 	/* set the cs_enforced flags in the map */
7484 	if (proc_getcsflags(p) & CS_ENFORCEMENT) {
7485 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), TRUE);
7486 	} else {
7487 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), FALSE);
7488 	}
7489 
7490 	/*
7491 	 * image activation may be failed due to policy
7492 	 * which is unexpected but security framework does not
7493 	 * approve of exec, kill and return immediately.
7494 	 */
7495 	if (imgp->ip_mac_return != 0) {
7496 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7497 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
7498 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7499 		error = imgp->ip_mac_return;
7500 		unexpected_failure = TRUE;
7501 		goto done;
7502 	}
7503 
7504 	if (imgp->ip_cs_error != OS_REASON_NULL) {
7505 		signature_failure_reason = imgp->ip_cs_error;
7506 		imgp->ip_cs_error = OS_REASON_NULL;
7507 		error = EACCES;
7508 		goto done;
7509 	}
7510 
7511 	/* call the launch constraints hook */
7512 	os_reason_t launch_constraint_reason;
7513 	if ((error = mac_proc_check_launch_constraints(p, imgp, &launch_constraint_reason)) != 0) {
7514 		signature_failure_reason = launch_constraint_reason;
7515 		goto done;
7516 	}
7517 
7518 #if XNU_TARGET_OS_OSX
7519 	/* Check for platform passed in spawn attr if iOS binary is being spawned */
7520 	if (proc_platform(p) == PLATFORM_IOS) {
7521 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
7522 		if (psa == NULL || psa->psa_platform == 0) {
7523 			boolean_t no_sandbox_entitled = FALSE;
7524 #if DEBUG || DEVELOPMENT
7525 			/*
7526 			 * Allow iOS binaries to spawn on internal systems
7527 			 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
7528 			 * boot-arg set to true
7529 			 */
7530 			if (unentitled_ios_sim_launch) {
7531 				no_sandbox_entitled = TRUE;
7532 			} else {
7533 				no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
7534 				    (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
7535 			}
7536 #endif /* DEBUG || DEVELOPMENT */
7537 			if (!no_sandbox_entitled) {
7538 				signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7539 				    EXEC_EXIT_REASON_WRONG_PLATFORM);
7540 				error = EACCES;
7541 				goto done;
7542 			}
7543 			printf("Allowing spawn of iOS binary %s since it has "
7544 			    "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
7545 			    "boot-arg set to true\n", p->p_name);
7546 		} else if (psa->psa_platform != PLATFORM_IOS) {
7547 			/* Simulator binary spawned with wrong platform */
7548 			signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7549 			    EXEC_EXIT_REASON_WRONG_PLATFORM);
7550 			error = EACCES;
7551 			goto done;
7552 		} else {
7553 			printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
7554 			    p->p_name);
7555 		}
7556 	}
7557 #endif /* XNU_TARGET_OS_OSX */
7558 
7559 	/* If the code signature came through the image activation path, we skip the
7560 	 * taskgated / externally attached path. */
7561 	if (imgp->ip_csflags & CS_SIGNED) {
7562 		error = 0;
7563 		goto done;
7564 	}
7565 
7566 	/* The rest of the code is for signatures that either already have been externally
7567 	 * attached (likely, but not necessarily by a previous run through the taskgated
7568 	 * path), or that will now be attached by taskgated. */
7569 
7570 	kr = task_get_task_access_port(proc_task(p), &port);
7571 	if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
7572 		error = 0;
7573 		if (require_success) {
7574 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7575 			    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
7576 			signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
7577 			error = EACCES;
7578 		}
7579 		goto done;
7580 	}
7581 
7582 	/*
7583 	 * taskgated returns KERN_SUCCESS if it has completed its work
7584 	 * and the exec should continue, KERN_FAILURE if the exec should
7585 	 * fail, or it may error out with different error code in an
7586 	 * event of mig failure (e.g. process was signalled during the
7587 	 * rpc call, taskgated died, mig server died etc.).
7588 	 */
7589 
7590 	kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
7591 	switch (kr) {
7592 	case KERN_SUCCESS:
7593 		error = 0;
7594 		break;
7595 	case KERN_FAILURE:
7596 		error = EACCES;
7597 
7598 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7599 		    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
7600 		signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
7601 		goto done;
7602 	default:
7603 		error = EACCES;
7604 
7605 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7606 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
7607 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
7608 		unexpected_failure = TRUE;
7609 		goto done;
7610 	}
7611 
7612 	/* Only do this if exec_resettextvp() did not fail */
7613 	if (p->p_textvp != NULLVP) {
7614 		csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
7615 
7616 		if (csb != NULL) {
7617 			/* As the enforcement we can do here is very limited, we only allow things that
7618 			 * are the only reason why this code path still exists:
7619 			 * Adhoc signed non-platform binaries without special cs_flags and without any
7620 			 * entitlements (unrestricted ones still pass AMFI). */
7621 			if (
7622 				/* Revalidate the blob if necessary through bumped generation count. */
7623 				(ubc_cs_generation_check(p->p_textvp) == 0 ||
7624 				ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
7625 				/* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
7626 				(csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
7627 				/* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
7628 				csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
7629 				CSSLOT_SIGNATURESLOT,
7630 				CSMAGIC_BLOBWRAPPER) == NULL &&
7631 				/* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
7632 				csb->csb_platform_binary == 0 &&
7633 				/* No entitlements, not even unrestricted ones. */
7634 				csb->csb_entitlements_blob == NULL &&
7635 				csb->csb_der_entitlements_blob == NULL) {
7636 				proc_lock(p);
7637 				proc_csflags_set(p, CS_SIGNED | CS_VALID);
7638 				proc_unlock(p);
7639 			} else {
7640 				uint8_t cdhash[CS_CDHASH_LEN];
7641 				char cdhash_string[CS_CDHASH_STRING_SIZE];
7642 				proc_getcdhash(p, cdhash);
7643 				cdhash_to_string(cdhash_string, cdhash);
7644 				printf("ignoring detached code signature on '%s' with cdhash '%s' "
7645 				    "because it is invalid, or not a simple adhoc signature.\n",
7646 				    p->p_name, cdhash_string);
7647 			}
7648 		}
7649 	}
7650 
7651 done:
7652 	if (0 == error) {
7653 		/*
7654 		 * Update the new process's signature-dependent process state.
7655 		 * state.
7656 		 */
7657 
7658 		error = proc_process_signature(p, &signature_failure_reason);
7659 	}
7660 
7661 	if (0 == error) {
7662 		/*
7663 		 * Update the new main thread's signature-dependent thread
7664 		 * state. This was also called when the thread was created,
7665 		 * but for the main thread the signature was not yet attached
7666 		 * at that time.
7667 		 */
7668 		kr = thread_process_signature(imgp->ip_new_thread, proc_get_task_raw(p));
7669 
7670 		if (kr != KERN_SUCCESS) {
7671 			error = EINVAL;
7672 			signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MACHINE_THREAD);
7673 		}
7674 	}
7675 
7676 	if (0 == error) {
7677 		/* The process's code signature related properties are
7678 		 * fully set up, so this is an opportune moment to log
7679 		 * platform binary execution, if desired. */
7680 		if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
7681 			uint8_t cdhash[CS_CDHASH_LEN];
7682 			char cdhash_string[CS_CDHASH_STRING_SIZE];
7683 			proc_getcdhash(p, cdhash);
7684 			cdhash_to_string(cdhash_string, cdhash);
7685 
7686 			os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
7687 			    "'%s' with cdhash %s\n", p->p_name, cdhash_string);
7688 		}
7689 	} else {
7690 		if (!unexpected_failure) {
7691 			proc_csflags_set(p, CS_KILLED);
7692 		}
7693 		/* make very sure execution fails */
7694 		if (vfexec || spawn) {
7695 			assert(signature_failure_reason != OS_REASON_NULL);
7696 			psignal_vfork_with_reason(p, proc_task(p), imgp->ip_new_thread,
7697 			    SIGKILL, signature_failure_reason);
7698 			signature_failure_reason = OS_REASON_NULL;
7699 			error = 0;
7700 		} else {
7701 			assert(signature_failure_reason != OS_REASON_NULL);
7702 			psignal_with_reason(p, SIGKILL, signature_failure_reason);
7703 			signature_failure_reason = OS_REASON_NULL;
7704 		}
7705 	}
7706 
7707 	if (port != IPC_PORT_NULL) {
7708 		ipc_port_release_send(port);
7709 	}
7710 
7711 	/* If we hit this, we likely would have leaked an exit reason */
7712 	assert(signature_failure_reason == OS_REASON_NULL);
7713 	return error;
7714 }
7715 
7716 /*
7717  * Typically as soon as we start executing this process, the
7718  * first instruction will trigger a VM fault to bring the text
7719  * pages (as executable) into the address space, followed soon
7720  * thereafter by dyld data structures (for dynamic executable).
7721  * To optimize this, as well as improve support for hardware
7722  * debuggers that can only access resident pages present
7723  * in the process' page tables, we prefault some pages if
7724  * possible. Errors are non-fatal.
7725  */
7726 #ifndef PREVENT_CALLER_STACK_USE
7727 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
7728 #endif
7729 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(proc_t p __unused,struct image_params * imgp,load_result_t * load_result)7730 exec_prefault_data(proc_t p __unused, struct image_params *imgp, load_result_t *load_result)
7731 {
7732 	int ret;
7733 	size_t expected_all_image_infos_size;
7734 	kern_return_t kr;
7735 
7736 	/*
7737 	 * Prefault executable or dyld entry point.
7738 	 */
7739 	if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7740 		DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
7741 	}
7742 	kr = vm_fault(current_map(),
7743 	    vm_map_trunc_page(load_result->entry_point,
7744 	    vm_map_page_mask(current_map())),
7745 	    VM_PROT_READ | VM_PROT_EXECUTE,
7746 	    FALSE, VM_KERN_MEMORY_NONE,
7747 	    THREAD_UNINT, NULL, 0);
7748 	if (kr != KERN_SUCCESS) {
7749 		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);
7750 	}
7751 
7752 	if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7753 		expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
7754 	} else {
7755 		expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
7756 	}
7757 
7758 	/* Decode dyld anchor structure from <mach-o/dyld_images.h> */
7759 	if (load_result->dynlinker &&
7760 	    load_result->all_image_info_addr &&
7761 	    load_result->all_image_info_size >= expected_all_image_infos_size) {
7762 		union {
7763 			struct user64_dyld_all_image_infos      infos64;
7764 			struct user32_dyld_all_image_infos      infos32;
7765 		} all_image_infos;
7766 
7767 		/*
7768 		 * Pre-fault to avoid copyin() going through the trap handler
7769 		 * and recovery path.
7770 		 */
7771 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7772 			DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
7773 		}
7774 		kr = vm_fault(current_map(),
7775 		    vm_map_trunc_page(load_result->all_image_info_addr,
7776 		    vm_map_page_mask(current_map())),
7777 		    VM_PROT_READ | VM_PROT_WRITE,
7778 		    FALSE, VM_KERN_MEMORY_NONE,
7779 		    THREAD_UNINT, NULL, 0);
7780 		if (kr != KERN_SUCCESS) {
7781 //			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);
7782 		}
7783 		if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
7784 			/* all_image_infos straddles a page */
7785 			kr = vm_fault(current_map(),
7786 			    vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
7787 			    vm_map_page_mask(current_map())),
7788 			    VM_PROT_READ | VM_PROT_WRITE,
7789 			    FALSE, VM_KERN_MEMORY_NONE,
7790 			    THREAD_UNINT, NULL, 0);
7791 			if (kr != KERN_SUCCESS) {
7792 //				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);
7793 			}
7794 		}
7795 
7796 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7797 			DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
7798 		}
7799 		ret = copyin((user_addr_t)load_result->all_image_info_addr,
7800 		    &all_image_infos,
7801 		    expected_all_image_infos_size);
7802 		if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
7803 			user_addr_t notification_address;
7804 			user_addr_t dyld_image_address;
7805 			user_addr_t dyld_version_address;
7806 			user_addr_t dyld_all_image_infos_address;
7807 			user_addr_t dyld_slide_amount;
7808 
7809 			if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7810 				notification_address = (user_addr_t)all_image_infos.infos64.notification;
7811 				dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
7812 				dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
7813 				dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
7814 			} else {
7815 				notification_address = all_image_infos.infos32.notification;
7816 				dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
7817 				dyld_version_address = all_image_infos.infos32.dyldVersion;
7818 				dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
7819 			}
7820 
7821 			/*
7822 			 * dyld statically sets up the all_image_infos in its Mach-O
7823 			 * binary at static link time, with pointers relative to its default
7824 			 * load address. Since ASLR might slide dyld before its first
7825 			 * instruction is executed, "dyld_slide_amount" tells us how far
7826 			 * dyld was loaded compared to its default expected load address.
7827 			 * All other pointers into dyld's image should be adjusted by this
7828 			 * amount. At some point later, dyld will fix up pointers to take
7829 			 * into account the slide, at which point the all_image_infos_address
7830 			 * field in the structure will match the runtime load address, and
7831 			 * "dyld_slide_amount" will be 0, if we were to consult it again.
7832 			 */
7833 
7834 			dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
7835 
7836 #if 0
7837 			kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
7838 			    (uint64_t)load_result->all_image_info_addr,
7839 			    all_image_infos.infos32.version,
7840 			    (uint64_t)notification_address,
7841 			    (uint64_t)dyld_image_address,
7842 			    (uint64_t)dyld_version_address,
7843 			    (uint64_t)dyld_all_image_infos_address);
7844 #endif
7845 
7846 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7847 				DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
7848 			}
7849 			kr = vm_fault(current_map(),
7850 			    vm_map_trunc_page(notification_address + dyld_slide_amount,
7851 			    vm_map_page_mask(current_map())),
7852 			    VM_PROT_READ | VM_PROT_EXECUTE,
7853 			    FALSE, VM_KERN_MEMORY_NONE,
7854 			    THREAD_UNINT, NULL, 0);
7855 			if (kr != KERN_SUCCESS) {
7856 //				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);
7857 			}
7858 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7859 				DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
7860 			}
7861 			kr = vm_fault(current_map(),
7862 			    vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
7863 			    vm_map_page_mask(current_map())),
7864 			    VM_PROT_READ | VM_PROT_EXECUTE,
7865 			    FALSE, VM_KERN_MEMORY_NONE,
7866 			    THREAD_UNINT, NULL, 0);
7867 			if (kr != KERN_SUCCESS) {
7868 //				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);
7869 			}
7870 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7871 				DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
7872 			}
7873 			kr = vm_fault(current_map(),
7874 			    vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
7875 			    vm_map_page_mask(current_map())),
7876 			    VM_PROT_READ,
7877 			    FALSE, VM_KERN_MEMORY_NONE,
7878 			    THREAD_UNINT, NULL, 0);
7879 			if (kr != KERN_SUCCESS) {
7880 //				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);
7881 			}
7882 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7883 				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);
7884 			}
7885 			kr = vm_fault(current_map(),
7886 			    vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
7887 			    vm_map_page_mask(current_map())),
7888 			    VM_PROT_READ | VM_PROT_WRITE,
7889 			    FALSE, VM_KERN_MEMORY_NONE,
7890 			    THREAD_UNINT, NULL, 0);
7891 			if (kr != KERN_SUCCESS) {
7892 //				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);
7893 			}
7894 		}
7895 	}
7896 }
7897 
7898 static int
7899 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
7900 {
7901 #pragma unused(oidp, arg2, req)
7902 	int changed;
7903 	errno_t error;
7904 	uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
7905 
7906 	error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
7907 	if (error) {
7908 		return error;
7909 	}
7910 
7911 	if (changed) {
7912 		os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
7913 	}
7914 
7915 	return 0;
7916 }
7917 
7918 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
7919