xref: /xnu-10063.141.1/bsd/kern/kern_exec.c (revision d8b80295118ef25ac3a784134bcf95cd8e88109f)
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 #include <CodeSignature/Entitlements.h>
187 
188 #include <mach/exclaves.h>
189 
190 extern boolean_t vm_darkwake_mode;
191 
192 /* enable crash reports on various exec failures */
193 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
194 
195 #if XNU_TARGET_OS_OSX
196 #if __has_feature(ptrauth_calls)
197 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
198 #endif /* __has_feature(ptrauth_calls) */
199 
200 #if DEBUG || DEVELOPMENT
201 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
202 #endif /* DEBUG || DEVELOPMENT */
203 #endif /* XNU_TARGET_OS_OSX */
204 
205 #if CONFIG_DTRACE
206 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
207 extern void dtrace_proc_exec(proc_t);
208 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
209 
210 /*
211  * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
212  * we will store its value before actually calling it.
213  */
214 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
215 
216 #include <sys/dtrace_ptss.h>
217 #endif
218 
219 #if __has_feature(ptrauth_calls)
220 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
221     "vm_shared_region_per_team_id", 1);
222 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
223     "vm_shared_region_by_entitlement", 1);
224 
225 /* Upon userland request, reslide the shared cache. */
226 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
227     "vm_shared_region_reslide_aslr",
228 #if CONFIG_RESLIDE_SHARED_CACHE
229     1
230 #else
231     0
232 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
233     );
234 
235 /*
236  * Flag to control what processes should get shared cache randomize resliding
237  * after a fault in the shared cache region:
238  *
239  * 0 - all processes get a new randomized slide
240  * 1 - only platform processes get a new randomized slide
241  */
242 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
243     "vm_shared_region_reslide_restrict", 1);
244 
245 #if DEVELOPMENT || DEBUG
246 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
247     CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
248 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
249     CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
250 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
251     CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
252 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
253     CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
254 #endif
255 #endif /* __has_feature(ptrauth_calls) */
256 
257 #if DEVELOPMENT || DEBUG
258 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", true);
259 #else
260 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", false);
261 #endif
262 extern kern_return_t kern_register_userspace_coredump(task_t task, const char * name);
263 #define USERSPACE_COREDUMP_PANIC_ENTITLEMENT "com.apple.private.enable-coredump-on-panic"
264 #define USERSPACE_COREDUMP_PANIC_SEED_ENTITLEMENT \
265 	"com.apple.private.enable-coredump-on-panic-seed-privacy-approved"
266 
267 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
268 extern void task_set_did_exec_flag(task_t task);
269 extern void task_clear_exec_copy_flag(task_t task);
270 proc_t proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task,
271     task_t new_task, struct image_params *imgp, void **inherit);
272 boolean_t task_is_active(task_t);
273 boolean_t thread_is_active(thread_t thread);
274 void thread_copy_resource_info(thread_t dst_thread, thread_t src_thread);
275 void *ipc_importance_exec_switch_task(task_t old_task, task_t new_task);
276 extern void ipc_importance_release(void *elem);
277 extern boolean_t task_has_watchports(task_t task);
278 extern void task_set_no_smt(task_t task);
279 #if defined(HAS_APPLE_PAC)
280 char *task_get_vm_shared_region_id_and_jop_pid(task_t task, uint64_t *jop_pid);
281 #endif
282 task_t convert_port_to_task(ipc_port_t port);
283 
284 #if CONFIG_EXCLAVES
285 int task_add_conclave(task_t task, void *vnode, int64_t off, const char *task_conclave_id);
286 kern_return_t task_inherit_conclave(task_t old_task, task_t new_task, void *vnode, int64_t off);
287 #endif /* CONFIG_EXCLAVES */
288 
289 
290 /*
291  * Mach things for which prototypes are unavailable from Mach headers
292  */
293 #define IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND 0x1
294 void            ipc_task_enable(
295 	task_t          task);
296 void            ipc_task_reset(
297 	task_t          task);
298 void            ipc_thread_reset(
299 	thread_t        thread);
300 kern_return_t ipc_object_copyin(
301 	ipc_space_t             space,
302 	mach_port_name_t        name,
303 	mach_msg_type_name_t    msgt_name,
304 	ipc_object_t            *objectp,
305 	mach_port_context_t     context,
306 	mach_msg_guard_flags_t  *guard_flags,
307 	uint32_t                kmsg_flags);
308 void ipc_port_release_send(ipc_port_t);
309 
310 #if DEVELOPMENT || DEBUG
311 void task_importance_update_owner_info(task_t);
312 #endif
313 
314 extern struct savearea *get_user_regs(thread_t);
315 
316 __attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
317 
318 #include <kern/thread.h>
319 #include <kern/task.h>
320 #include <kern/ast.h>
321 #include <kern/mach_loader.h>
322 #include <kern/mach_fat.h>
323 #include <mach-o/fat.h>
324 #include <mach-o/loader.h>
325 #include <machine/vmparam.h>
326 #include <sys/imgact.h>
327 
328 #include <sys/sdt.h>
329 
330 
331 /*
332  * EAI_ITERLIMIT	The maximum number of times to iterate an image
333  *			activator in exec_activate_image() before treating
334  *			it as malformed/corrupt.
335  */
336 #define EAI_ITERLIMIT           3
337 
338 /*
339  * For #! interpreter parsing
340  */
341 #define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
342 #define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
343 
344 extern vm_map_t bsd_pageable_map;
345 extern const struct fileops vnops;
346 extern int nextpidversion;
347 
348 
349 #define USER_ADDR_ALIGN(addr, val) \
350 	( ( (user_addr_t)(addr) + (val) - 1) \
351 	        & ~((val) - 1) )
352 
353 /*
354  * For subsystem root support
355  */
356 #define SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT "com.apple.private.spawn-subsystem-root"
357 
358 /*
359  * Allow setting p_crash_behavior to trigger panic on crash
360  */
361 #define SPAWN_SET_PANIC_CRASH_BEHAVIOR "com.apple.private.spawn-panic-crash-behavior"
362 
363 /* Platform Code Exec Logging */
364 static int platform_exec_logging = 0;
365 
366 SYSCTL_DECL(_security_mac);
367 
368 SYSCTL_INT(_security_mac, OID_AUTO, platform_exec_logging, CTLFLAG_RW, &platform_exec_logging, 0,
369     "log cdhashes for all platform binary executions");
370 
371 static os_log_t peLog = OS_LOG_DEFAULT;
372 
373 struct exception_port_action_t {
374 	ipc_port_t port;
375 	_ps_port_action_t *port_action;
376 };
377 
378 struct exec_port_actions {
379 	uint32_t exception_port_count;
380 	uint32_t portwatch_count;
381 	uint32_t registered_count;
382 	struct exception_port_action_t *excport_array;
383 	ipc_port_t *portwatch_array;
384 	ipc_port_t registered_array[TASK_PORT_REGISTER_MAX];
385 };
386 
387 struct image_params;    /* Forward */
388 static int exec_activate_image(struct image_params *imgp);
389 static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
390 static int load_return_to_errno(load_return_t lrtn);
391 static int execargs_alloc(struct image_params *imgp);
392 static int execargs_free(struct image_params *imgp);
393 static int exec_check_permissions(struct image_params *imgp);
394 static int exec_extract_strings(struct image_params *imgp);
395 static int exec_add_apple_strings(struct image_params *imgp, const load_result_t *load_result);
396 static int exec_handle_sugid(struct image_params *imgp);
397 static int sugid_scripts = 0;
398 SYSCTL_INT(_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
399 static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
400 static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
401 static void exec_resettextvp(proc_t, struct image_params *);
402 static int process_signature(proc_t, struct image_params *);
403 static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
404 static errno_t exec_handle_port_actions(struct image_params *imgp,
405     struct exec_port_actions *port_actions);
406 static errno_t exec_handle_exception_port_actions(const struct image_params *imgp,
407     const struct exec_port_actions *port_actions);
408 static errno_t exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
409     task_role_t psa_darwin_role, struct exec_port_actions *port_actions);
410 static void exec_port_actions_destroy(struct exec_port_actions *port_actions);
411 
412 /*
413  * exec_add_user_string
414  *
415  * Add the requested string to the string space area.
416  *
417  * Parameters;	struct image_params *		image parameter block
418  *		user_addr_t			string to add to strings area
419  *		int				segment from which string comes
420  *		boolean_t			TRUE if string contributes to NCARGS
421  *
422  * Returns:	0			Success
423  *		!0			Failure errno from copyinstr()
424  *
425  * Implicit returns:
426  *		(imgp->ip_strendp)	updated location of next add, if any
427  *		(imgp->ip_strspace)	updated byte count of space remaining
428  *		(imgp->ip_argspace) updated byte count of space in NCARGS
429  */
430 __attribute__((noinline))
431 static int
exec_add_user_string(struct image_params * imgp,user_addr_t str,int seg,boolean_t is_ncargs)432 exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
433 {
434 	int error = 0;
435 
436 	do {
437 		size_t len = 0;
438 		int space;
439 
440 		if (is_ncargs) {
441 			space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
442 		} else {
443 			space = imgp->ip_strspace;
444 		}
445 
446 		if (space <= 0) {
447 			error = E2BIG;
448 			break;
449 		}
450 
451 		if (!UIO_SEG_IS_USER_SPACE(seg)) {
452 			char *kstr = CAST_DOWN(char *, str);     /* SAFE */
453 			error = copystr(kstr, imgp->ip_strendp, space, &len);
454 		} else {
455 			error = copyinstr(str, imgp->ip_strendp, space, &len);
456 		}
457 
458 		imgp->ip_strendp += len;
459 		imgp->ip_strspace -= len;
460 		if (is_ncargs) {
461 			imgp->ip_argspace -= len;
462 		}
463 	} while (error == ENAMETOOLONG);
464 
465 	return error;
466 }
467 
468 /*
469  * dyld is now passed the executable path as a getenv-like variable
470  * in the same fashion as the stack_guard and malloc_entropy keys.
471  */
472 #define EXECUTABLE_KEY "executable_path="
473 
474 /*
475  * exec_save_path
476  *
477  * To support new app package launching for Mac OS X, the dyld needs the
478  * first argument to execve() stored on the user stack.
479  *
480  * Save the executable path name at the bottom of the strings area and set
481  * the argument vector pointer to the location following that to indicate
482  * the start of the argument and environment tuples, setting the remaining
483  * string space count to the size of the string area minus the path length.
484  *
485  * Parameters;	struct image_params *		image parameter block
486  *		char *				path used to invoke program
487  *		int				segment from which path comes
488  *
489  * Returns:	int			0	Success
490  *		EFAULT				Bad address
491  *	copy[in]str:EFAULT			Bad address
492  *	copy[in]str:ENAMETOOLONG		Filename too long
493  *
494  * Implicit returns:
495  *		(imgp->ip_strings)		saved path
496  *		(imgp->ip_strspace)		space remaining in ip_strings
497  *		(imgp->ip_strendp)		start of remaining copy area
498  *		(imgp->ip_argspace)		space remaining of NCARGS
499  *		(imgp->ip_applec)		Initial applev[0]
500  *
501  * Note:	We have to do this before the initial namei() since in the
502  *		path contains symbolic links, namei() will overwrite the
503  *		original path buffer contents.  If the last symbolic link
504  *		resolved was a relative pathname, we would lose the original
505  *		"path", which could be an absolute pathname. This might be
506  *		unacceptable for dyld.
507  */
508 static int
exec_save_path(struct image_params * imgp,user_addr_t path,int seg,const char ** excpath)509 exec_save_path(struct image_params *imgp, user_addr_t path, int seg, const char **excpath)
510 {
511 	int error;
512 	size_t len;
513 	char *kpath;
514 
515 	// imgp->ip_strings can come out of a cache, so we need to obliterate the
516 	// old path.
517 	memset(imgp->ip_strings, '\0', strlen(EXECUTABLE_KEY) + MAXPATHLEN);
518 
519 	len = MIN(MAXPATHLEN, imgp->ip_strspace);
520 
521 	switch (seg) {
522 	case UIO_USERSPACE32:
523 	case UIO_USERSPACE64:   /* Same for copyin()... */
524 		error = copyinstr(path, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
525 		break;
526 	case UIO_SYSSPACE:
527 		kpath = CAST_DOWN(char *, path); /* SAFE */
528 		error = copystr(kpath, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
529 		break;
530 	default:
531 		error = EFAULT;
532 		break;
533 	}
534 
535 	if (!error) {
536 		bcopy(EXECUTABLE_KEY, imgp->ip_strings, strlen(EXECUTABLE_KEY));
537 		len += strlen(EXECUTABLE_KEY);
538 
539 		imgp->ip_strendp += len;
540 		imgp->ip_strspace -= len;
541 
542 		if (excpath) {
543 			*excpath = imgp->ip_strings + strlen(EXECUTABLE_KEY);
544 		}
545 	}
546 
547 	return error;
548 }
549 
550 /*
551  * exec_reset_save_path
552  *
553  * If we detect a shell script, we need to reset the string area
554  * state so that the interpreter can be saved onto the stack.
555  *
556  * Parameters;	struct image_params *		image parameter block
557  *
558  * Returns:	int			0	Success
559  *
560  * Implicit returns:
561  *		(imgp->ip_strings)		saved path
562  *		(imgp->ip_strspace)		space remaining in ip_strings
563  *		(imgp->ip_strendp)		start of remaining copy area
564  *		(imgp->ip_argspace)		space remaining of NCARGS
565  *
566  */
567 static int
exec_reset_save_path(struct image_params * imgp)568 exec_reset_save_path(struct image_params *imgp)
569 {
570 	imgp->ip_strendp = imgp->ip_strings;
571 	imgp->ip_argspace = NCARGS;
572 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
573 
574 	return 0;
575 }
576 
577 /*
578  * exec_shell_imgact
579  *
580  * Image activator for interpreter scripts.  If the image begins with
581  * the characters "#!", then it is an interpreter script.  Verify the
582  * length of the script line indicating the interpreter is not in
583  * excess of the maximum allowed size.  If this is the case, then
584  * break out the arguments, if any, which are separated by white
585  * space, and copy them into the argument save area as if they were
586  * provided on the command line before all other arguments.  The line
587  * ends when we encounter a comment character ('#') or newline.
588  *
589  * Parameters;	struct image_params *	image parameter block
590  *
591  * Returns:	-1			not an interpreter (keep looking)
592  *		-3			Success: interpreter: relookup
593  *		>0			Failure: interpreter: error number
594  *
595  * A return value other than -1 indicates subsequent image activators should
596  * not be given the opportunity to attempt to activate the image.
597  */
598 static int
exec_shell_imgact(struct image_params * imgp)599 exec_shell_imgact(struct image_params *imgp)
600 {
601 	char *vdata = imgp->ip_vdata;
602 	char *ihp;
603 	char *line_startp, *line_endp;
604 	char *interp;
605 
606 	/*
607 	 * Make sure it's a shell script.  If we've already redirected
608 	 * from an interpreted file once, don't do it again.
609 	 */
610 	if (vdata[0] != '#' ||
611 	    vdata[1] != '!' ||
612 	    (imgp->ip_flags & IMGPF_INTERPRET) != 0) {
613 		return -1;
614 	}
615 
616 	if (imgp->ip_origcputype != 0) {
617 		/* Fat header previously matched, don't allow shell script inside */
618 		return -1;
619 	}
620 
621 	imgp->ip_flags |= IMGPF_INTERPRET;
622 	imgp->ip_interp_sugid_fd = -1;
623 	imgp->ip_interp_buffer[0] = '\0';
624 
625 	/* Check to see if SUGID scripts are permitted.  If they aren't then
626 	 * clear the SUGID bits.
627 	 * imgp->ip_vattr is known to be valid.
628 	 */
629 	if (sugid_scripts == 0) {
630 		imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
631 	}
632 
633 	/* Try to find the first non-whitespace character */
634 	for (ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++) {
635 		if (IS_EOL(*ihp)) {
636 			/* Did not find interpreter, "#!\n" */
637 			return ENOEXEC;
638 		} else if (IS_WHITESPACE(*ihp)) {
639 			/* Whitespace, like "#!    /bin/sh\n", keep going. */
640 		} else {
641 			/* Found start of interpreter */
642 			break;
643 		}
644 	}
645 
646 	if (ihp == &vdata[IMG_SHSIZE]) {
647 		/* All whitespace, like "#!           " */
648 		return ENOEXEC;
649 	}
650 
651 	line_startp = ihp;
652 
653 	/* Try to find the end of the interpreter+args string */
654 	for (; ihp < &vdata[IMG_SHSIZE]; ihp++) {
655 		if (IS_EOL(*ihp)) {
656 			/* Got it */
657 			break;
658 		} else {
659 			/* Still part of interpreter or args */
660 		}
661 	}
662 
663 	if (ihp == &vdata[IMG_SHSIZE]) {
664 		/* A long line, like "#! blah blah blah" without end */
665 		return ENOEXEC;
666 	}
667 
668 	/* Backtrack until we find the last non-whitespace */
669 	while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
670 		ihp--;
671 	}
672 
673 	/* The character after the last non-whitespace is our logical end of line */
674 	line_endp = ihp + 1;
675 
676 	/*
677 	 * Now we have pointers to the usable part of:
678 	 *
679 	 * "#!  /usr/bin/int first    second   third    \n"
680 	 *      ^ line_startp                       ^ line_endp
681 	 */
682 
683 	/* copy the interpreter name */
684 	interp = imgp->ip_interp_buffer;
685 	for (ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++) {
686 		*interp++ = *ihp;
687 	}
688 	*interp = '\0';
689 
690 	exec_reset_save_path(imgp);
691 	exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
692 	    UIO_SYSSPACE, NULL);
693 
694 	/* Copy the entire interpreter + args for later processing into argv[] */
695 	interp = imgp->ip_interp_buffer;
696 	for (ihp = line_startp; (ihp < line_endp); ihp++) {
697 		*interp++ = *ihp;
698 	}
699 	*interp = '\0';
700 
701 #if CONFIG_SETUID
702 	/*
703 	 * If we have an SUID or SGID script, create a file descriptor
704 	 * from the vnode and pass /dev/fd/%d instead of the actual
705 	 * path name so that the script does not get opened twice
706 	 */
707 	if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
708 		proc_t p;
709 		struct fileproc *fp;
710 		int fd;
711 		int error;
712 
713 		p = vfs_context_proc(imgp->ip_vfs_context);
714 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &fd);
715 		if (error) {
716 			return error;
717 		}
718 
719 		fp->fp_glob->fg_flag = FREAD;
720 		fp->fp_glob->fg_ops = &vnops;
721 		fp_set_data(fp, imgp->ip_vp);
722 
723 		proc_fdlock(p);
724 		procfdtbl_releasefd(p, fd, NULL);
725 		fp_drop(p, fd, fp, 1);
726 		proc_fdunlock(p);
727 		vnode_ref(imgp->ip_vp);
728 
729 		imgp->ip_interp_sugid_fd = fd;
730 	}
731 #endif /* CONFIG_SETUID */
732 
733 	return -3;
734 }
735 
736 
737 
738 /*
739  * exec_fat_imgact
740  *
741  * Image activator for fat 1.0 binaries.  If the binary is fat, then we
742  * need to select an image from it internally, and make that the image
743  * we are going to attempt to execute.  At present, this consists of
744  * reloading the first page for the image with a first page from the
745  * offset location indicated by the fat header.
746  *
747  * Parameters;	struct image_params *	image parameter block
748  *
749  * Returns:	-1			not a fat binary (keep looking)
750  *		-2			Success: encapsulated binary: reread
751  *		>0			Failure: error number
752  *
753  * Important:	This image activator is byte order neutral.
754  *
755  * Note:	A return value other than -1 indicates subsequent image
756  *		activators should not be given the opportunity to attempt
757  *		to activate the image.
758  *
759  *              If we find an encapsulated binary, we make no assertions
760  *		about its  validity; instead, we leave that up to a rescan
761  *		for an activator to claim it, and, if it is claimed by one,
762  *		that activator is responsible for determining validity.
763  */
764 static int
exec_fat_imgact(struct image_params * imgp)765 exec_fat_imgact(struct image_params *imgp)
766 {
767 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
768 	kauth_cred_t cred = kauth_cred_proc_ref(p);
769 	struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
770 	struct _posix_spawnattr *psa = NULL;
771 	struct fat_arch fat_arch;
772 	int resid, error;
773 	load_return_t lret;
774 
775 	if (imgp->ip_origcputype != 0) {
776 		/* Fat header previously matched, don't allow another fat file inside */
777 		error = -1; /* not claimed */
778 		goto bad;
779 	}
780 
781 	/* Make sure it's a fat binary */
782 	if (OSSwapBigToHostInt32(fat_header->magic) != FAT_MAGIC) {
783 		error = -1; /* not claimed */
784 		goto bad;
785 	}
786 
787 	/* imgp->ip_vdata has PAGE_SIZE, zerofilled if the file is smaller */
788 	lret = fatfile_validate_fatarches((vm_offset_t)fat_header, PAGE_SIZE,
789 	    (off_t)imgp->ip_vattr->va_data_size);
790 	if (lret != LOAD_SUCCESS) {
791 		error = load_return_to_errno(lret);
792 		goto bad;
793 	}
794 
795 	/* If posix_spawn binprefs exist, respect those prefs. */
796 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
797 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
798 		uint32_t pr = 0;
799 
800 		/* Check each preference listed against all arches in header */
801 		for (pr = 0; pr < NBINPREFS; pr++) {
802 			cpu_type_t pref = psa->psa_binprefs[pr];
803 			cpu_type_t subpref = psa->psa_subcpuprefs[pr];
804 
805 			if (pref == 0) {
806 				/* No suitable arch in the pref list */
807 				error = EBADARCH;
808 				goto bad;
809 			}
810 
811 			if (pref == CPU_TYPE_ANY) {
812 				/* Fall through to regular grading */
813 				goto regular_grading;
814 			}
815 
816 			lret = fatfile_getbestarch_for_cputype(pref,
817 			    subpref,
818 			    (vm_offset_t)fat_header,
819 			    PAGE_SIZE,
820 			    imgp,
821 			    &fat_arch);
822 			if (lret == LOAD_SUCCESS) {
823 				goto use_arch;
824 			}
825 		}
826 
827 		/* Requested binary preference was not honored */
828 		error = EBADEXEC;
829 		goto bad;
830 	}
831 
832 regular_grading:
833 	/* Look up our preferred architecture in the fat file. */
834 	lret = fatfile_getbestarch((vm_offset_t)fat_header,
835 	    PAGE_SIZE,
836 	    imgp,
837 	    &fat_arch,
838 	    (p->p_flag & P_AFFINITY) != 0);
839 	if (lret != LOAD_SUCCESS) {
840 		error = load_return_to_errno(lret);
841 		goto bad;
842 	}
843 
844 use_arch:
845 	/* Read the Mach-O header out of fat_arch */
846 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
847 	    PAGE_SIZE, fat_arch.offset,
848 	    UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
849 	    cred, &resid, p);
850 	if (error) {
851 		goto bad;
852 	}
853 
854 	if (resid) {
855 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
856 	}
857 
858 	/* Success.  Indicate we have identified an encapsulated binary */
859 	error = -2;
860 	imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
861 	imgp->ip_arch_size = (user_size_t)fat_arch.size;
862 	imgp->ip_origcputype = fat_arch.cputype;
863 	imgp->ip_origcpusubtype = fat_arch.cpusubtype;
864 
865 bad:
866 	kauth_cred_unref(&cred);
867 	return error;
868 }
869 
870 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)871 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
872 {
873 	int ret;
874 
875 	(void)task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0);
876 	task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
877 	if (result->is_64bit_addr) {
878 		OSBitOrAtomic(P_LP64, &p->p_flag);
879 		get_bsdthread_info(thread)->uu_flag |= UT_LP64;
880 	} else {
881 		OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
882 		get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
883 	}
884 	task_set_mach_header_address(task, result->mach_header);
885 
886 	ret = thread_state_initialize(thread);
887 	if (ret != KERN_SUCCESS) {
888 		return ret;
889 	}
890 
891 	if (result->threadstate) {
892 		uint32_t *ts = result->threadstate;
893 		uint32_t total_size = (uint32_t)result->threadstate_sz;
894 
895 		while (total_size > 0) {
896 			uint32_t flavor = *ts++;
897 			uint32_t size = *ts++;
898 
899 			ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
900 			if (ret) {
901 				return ret;
902 			}
903 			ts += size;
904 			total_size -= (size + 2) * sizeof(uint32_t);
905 		}
906 	}
907 
908 	thread_setentrypoint(thread, result->entry_point);
909 
910 	return KERN_SUCCESS;
911 }
912 
913 #if (DEVELOPMENT || DEBUG)
914 extern char panic_on_proc_crash[];
915 extern int use_panic_on_proc_crash;
916 
917 extern char panic_on_proc_exit[];
918 extern int use_panic_on_proc_exit;
919 
920 extern char panic_on_proc_spawn_fail[];
921 extern int use_panic_on_proc_spawn_fail;
922 #endif
923 
924 void
set_proc_name(struct image_params * imgp,proc_t p)925 set_proc_name(struct image_params *imgp, proc_t p)
926 {
927 	int p_name_len = sizeof(p->p_name) - 1;
928 
929 	if (imgp->ip_ndp->ni_cnd.cn_namelen > p_name_len) {
930 		imgp->ip_ndp->ni_cnd.cn_namelen = p_name_len;
931 	}
932 
933 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name,
934 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
935 	p->p_name[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
936 
937 	if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN) {
938 		imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
939 	}
940 
941 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
942 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
943 	p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
944 
945 #if DEVELOPMENT || DEBUG
946 	/*
947 	 * This happens during image activation, so the crash behavior flags from
948 	 * posix_spawn will have already been set. So we don't have to worry about
949 	 * this being overridden.
950 	 */
951 	if (use_panic_on_proc_crash && strcmp(p->p_comm, panic_on_proc_crash) == 0) {
952 		printf("will panic on proc crash: %s\n", p->p_comm);
953 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_CRASH;
954 	}
955 
956 	if (use_panic_on_proc_exit && strcmp(p->p_comm, panic_on_proc_exit) == 0) {
957 		printf("will panic on proc exit: %s\n", p->p_comm);
958 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_EXIT;
959 	}
960 
961 	if (use_panic_on_proc_spawn_fail && strcmp(p->p_comm, panic_on_proc_spawn_fail) == 0) {
962 		printf("will panic on proc spawn fail: %s\n", p->p_comm);
963 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_SPAWN_FAIL;
964 	}
965 #endif
966 }
967 
968 #if __has_feature(ptrauth_calls)
969 /**
970  * Returns a team ID string that may be used to assign a shared region.
971  *
972  * Platform binaries do not have team IDs and will return NULL.  Non-platform
973  * binaries without a team ID will be assigned an artificial team ID of ""
974  * (empty string) so that they will not be assigned to the default shared
975  * region.
976  *
977  * @param imgp image parameter block
978  * @return NULL if this is a platform binary, or an appropriate team ID string
979  *         otherwise
980  */
981 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)982 get_teamid_for_shared_region(struct image_params *imgp)
983 {
984 	assert(imgp->ip_vp != NULL);
985 
986 	const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
987 	if (ret) {
988 		return ret;
989 	}
990 
991 	struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
992 	if (csblob_get_platform_binary(blob)) {
993 		return NULL;
994 	} else {
995 		static const char *NO_TEAM_ID = "";
996 		return NO_TEAM_ID;
997 	}
998 }
999 
1000 /**
1001  * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
1002  *
1003  * @param cpusubtype Mach-O style CPU subtype
1004  * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
1005  */
1006 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)1007 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
1008 {
1009 	return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1010 	       CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
1011 }
1012 
1013 #endif /* __has_feature(ptrauth_calls) */
1014 
1015 /**
1016  * Returns whether a type/subtype slice matches the requested
1017  * type/subtype.
1018  *
1019  * @param mask Bits to mask from the requested/tested cpu type
1020  * @param req_cpu Requested cpu type
1021  * @param req_subcpu Requested cpu subtype
1022  * @param test_cpu Tested slice cpu type
1023  * @param test_subcpu Tested slice cpu subtype
1024  */
1025 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)1026 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
1027     cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
1028     cpu_subtype_t test_subcpu)
1029 {
1030 	if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
1031 		return FALSE;
1032 	}
1033 
1034 	test_subcpu &= ~CPU_SUBTYPE_MASK;
1035 	req_subcpu  &= ~CPU_SUBTYPE_MASK;
1036 
1037 	if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
1038 		return FALSE;
1039 	}
1040 
1041 	return TRUE;
1042 }
1043 
1044 
1045 #define MIN_IOS_TPRO_SDK_VERSION        0x00100000
1046 #define MIN_OSX_TPRO_SDK_VERSION        0x000D0000
1047 #define MIN_TVOS_TPRO_SDK_VERSION       0x000D0000
1048 #define MIN_WATCHOS_TPRO_SDK_VERSION    0x00090000
1049 #define MIN_DRIVERKIT_TPRO_SDK_VERSION  0x00600000
1050 
1051 static void
exec_setup_tpro(struct image_params * imgp,load_result_t * load_result)1052 exec_setup_tpro(struct image_params *imgp, load_result_t *load_result)
1053 {
1054 	extern boolean_t xprr_tpro_enabled;
1055 	extern boolean_t enable_user_modifiable_perms;
1056 	uint32_t min_sdk_version = 0;
1057 
1058 	/* x86-64 translated code cannot take advantage of TPRO */
1059 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1060 		return;
1061 	}
1062 
1063 	/* Do not enable on 32-bit VA targets */
1064 	if (!(imgp->ip_flags & IMGPF_IS_64BIT_ADDR)) {
1065 		return;
1066 	}
1067 
1068 	switch (load_result->ip_platform) {
1069 	case PLATFORM_IOS:
1070 	case PLATFORM_IOSSIMULATOR:
1071 	case PLATFORM_MACCATALYST:
1072 		min_sdk_version = MIN_IOS_TPRO_SDK_VERSION;
1073 		break;
1074 	case PLATFORM_MACOS:
1075 		min_sdk_version = MIN_OSX_TPRO_SDK_VERSION;
1076 		break;
1077 	case PLATFORM_TVOS:
1078 	case PLATFORM_TVOSSIMULATOR:
1079 		min_sdk_version = MIN_TVOS_TPRO_SDK_VERSION;
1080 		break;
1081 	case PLATFORM_WATCHOS:
1082 	case PLATFORM_WATCHOSSIMULATOR:
1083 		min_sdk_version = MIN_WATCHOS_TPRO_SDK_VERSION;
1084 		break;
1085 	case PLATFORM_DRIVERKIT:
1086 		min_sdk_version = MIN_DRIVERKIT_TPRO_SDK_VERSION;
1087 		break;
1088 	default:
1089 		/* TPRO is on by default for newer platforms */
1090 		break;
1091 	}
1092 
1093 }
1094 
1095 /*
1096  * If the passed in executable's vnode should use the RSR
1097  * shared region, then this should return TRUE, otherwise, return FALSE.
1098  */
1099 static uint32_t rsr_current_version = 0;
1100 boolean_t (*rsr_check_vnode)(void *vnode) = NULL;
1101 
1102 boolean_t
vnode_is_rsr(vnode_t vp)1103 vnode_is_rsr(vnode_t vp)
1104 {
1105 	if (!(vnode_isreg(vp) && vnode_tag(vp) == VT_APFS)) {
1106 		return FALSE;
1107 	}
1108 
1109 	if (rsr_check_vnode != NULL && rsr_check_vnode((void *)vp)) {
1110 		return TRUE;
1111 	}
1112 	return FALSE;
1113 }
1114 
1115 
1116 static inline void
encode_HR_entitlement(const char * entitlement,HR_flags_t mask,const struct image_params * imgp,load_result_t * load_result)1117 encode_HR_entitlement(const char *entitlement, HR_flags_t mask,
1118     const struct image_params *imgp, load_result_t *load_result)
1119 {
1120 	if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
1121 		load_result->hardened_runtime_binary |= mask;
1122 	}
1123 }
1124 
1125 uint32_t
rsr_get_version(void)1126 rsr_get_version(void)
1127 {
1128 	return os_atomic_load(&rsr_current_version, relaxed);
1129 }
1130 
1131 void
rsr_bump_version(void)1132 rsr_bump_version(void)
1133 {
1134 	os_atomic_inc(&rsr_current_version, relaxed);
1135 }
1136 
1137 #if XNU_TARGET_OS_OSX
1138 static int
1139 rsr_version_sysctl SYSCTL_HANDLER_ARGS
1140 {
1141 #pragma unused(arg1, arg2, oidp)
1142 	int value = rsr_get_version();
1143 	int error = SYSCTL_OUT(req, &value, sizeof(int));
1144 	if (error) {
1145 		return error;
1146 	}
1147 
1148 	if (!req->newptr) {
1149 		return 0;
1150 	}
1151 
1152 	error = SYSCTL_IN(req, &value, sizeof(int));
1153 	if (error) {
1154 		return error;
1155 	}
1156 	if (value != 0) {
1157 		rsr_bump_version();
1158 	}
1159 	return 0;
1160 }
1161 
1162 
1163 SYSCTL_PROC(_vm, OID_AUTO, shared_region_control,
1164     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
1165     0, 0, rsr_version_sysctl, "I", "");
1166 #endif /* XNU_TARGET_OS_OSX */
1167 
1168 /*
1169  * exec_mach_imgact
1170  *
1171  * Image activator for mach-o 1.0 binaries.
1172  *
1173  * Parameters;	struct image_params *	image parameter block
1174  *
1175  * Returns:	-1			not a fat binary (keep looking)
1176  *		-2			Success: encapsulated binary: reread
1177  *		>0			Failure: error number
1178  *		EBADARCH		Mach-o binary, but with an unrecognized
1179  *					architecture
1180  *		ENOMEM			No memory for child process after -
1181  *					can only happen after vfork()
1182  *
1183  * Important:	This image activator is NOT byte order neutral.
1184  *
1185  * Note:	A return value other than -1 indicates subsequent image
1186  *		activators should not be given the opportunity to attempt
1187  *		to activate the image.
1188  */
1189 static int
exec_mach_imgact(struct image_params * imgp)1190 exec_mach_imgact(struct image_params *imgp)
1191 {
1192 	struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1193 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
1194 	int                     error = 0;
1195 	task_t                  task;
1196 	task_t                  new_task = NULL; /* protected by vfexec */
1197 	thread_t                thread;
1198 	struct uthread          *uthread;
1199 	vm_map_t old_map = VM_MAP_NULL;
1200 	vm_map_t map = VM_MAP_NULL;
1201 	load_return_t           lret;
1202 	load_result_t           load_result = {};
1203 	struct _posix_spawnattr *psa = NULL;
1204 	int                     spawn = (imgp->ip_flags & IMGPF_SPAWN);
1205 	const int               vfexec = 0;
1206 	int                     exec = (imgp->ip_flags & IMGPF_EXEC);
1207 	os_reason_t             exec_failure_reason = OS_REASON_NULL;
1208 	boolean_t               reslide = FALSE;
1209 	char *                  userspace_coredump_name = NULL;
1210 
1211 	/*
1212 	 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1213 	 * is a reserved field on the end, so for the most part, we can
1214 	 * treat them as if they were identical. Reverse-endian Mach-O
1215 	 * binaries are recognized but not compatible.
1216 	 */
1217 	if ((mach_header->magic == MH_CIGAM) ||
1218 	    (mach_header->magic == MH_CIGAM_64)) {
1219 		error = EBADARCH;
1220 		goto bad;
1221 	}
1222 
1223 	if ((mach_header->magic != MH_MAGIC) &&
1224 	    (mach_header->magic != MH_MAGIC_64)) {
1225 		error = -1;
1226 		goto bad;
1227 	}
1228 
1229 	if (mach_header->filetype != MH_EXECUTE) {
1230 		error = -1;
1231 		goto bad;
1232 	}
1233 
1234 	if (imgp->ip_origcputype != 0) {
1235 		/* Fat header previously had an idea about this thin file */
1236 		if (imgp->ip_origcputype != mach_header->cputype ||
1237 		    imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1238 			error = EBADARCH;
1239 			goto bad;
1240 		}
1241 	} else {
1242 		imgp->ip_origcputype = mach_header->cputype;
1243 		imgp->ip_origcpusubtype = mach_header->cpusubtype;
1244 	}
1245 
1246 	task = current_task();
1247 	thread = current_thread();
1248 	uthread = get_bsdthread_info(thread);
1249 
1250 	if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1251 		imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1252 	}
1253 
1254 
1255 	/* If posix_spawn binprefs exist, respect those prefs. */
1256 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1257 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
1258 		int pr = 0;
1259 		for (pr = 0; pr < NBINPREFS; pr++) {
1260 			cpu_type_t pref = psa->psa_binprefs[pr];
1261 			cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1262 
1263 			if (pref == 0) {
1264 				/* No suitable arch in the pref list */
1265 				error = EBADARCH;
1266 				goto bad;
1267 			}
1268 
1269 			if (pref == CPU_TYPE_ANY) {
1270 				/* Jump to regular grading */
1271 				goto grade;
1272 			}
1273 
1274 			if (binary_match(CPU_ARCH_MASK, pref, subpref,
1275 			    imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1276 				goto grade;
1277 			}
1278 		}
1279 		error = EBADARCH;
1280 		goto bad;
1281 	}
1282 grade:
1283 	if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1284 	    imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1285 		error = EBADARCH;
1286 		goto bad;
1287 	}
1288 
1289 	if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1290 	    imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1291 #if __x86_64__
1292 		const char *excpath;
1293 		error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1294 		os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1295 #endif
1296 		error = EBADARCH;
1297 		goto bad;
1298 	}
1299 
1300 #if defined(HAS_APPLE_PAC)
1301 	assert(mach_header->cputype == CPU_TYPE_ARM64
1302 	    );
1303 
1304 	if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1305 	    arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1306 	    ) {
1307 		imgp->ip_flags &= ~IMGPF_NOJOP;
1308 	} else {
1309 		imgp->ip_flags |= IMGPF_NOJOP;
1310 	}
1311 #endif
1312 
1313 	/* Copy in arguments/environment from the old process */
1314 	error = exec_extract_strings(imgp);
1315 	if (error) {
1316 		goto bad;
1317 	}
1318 
1319 	AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1320 	    imgp->ip_endargv - imgp->ip_startargv);
1321 	AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1322 	    imgp->ip_endenvv - imgp->ip_endargv);
1323 
1324 
1325 
1326 	/* reset local idea of thread, uthread, task */
1327 	thread = imgp->ip_new_thread;
1328 	uthread = get_bsdthread_info(thread);
1329 	task = new_task = get_threadtask(thread);
1330 
1331 	/*
1332 	 *	Load the Mach-O file.
1333 	 *
1334 	 * NOTE: An error after this point  indicates we have potentially
1335 	 * destroyed or overwritten some process state while attempting an
1336 	 * execve() following a vfork(), which is an unrecoverable condition.
1337 	 * We send the new process an immediate SIGKILL to avoid it executing
1338 	 * any instructions in the mutated address space. For true spawns,
1339 	 * this is not the case, and "too late" is still not too late to
1340 	 * return an error code to the parent process.
1341 	 */
1342 
1343 	/*
1344 	 * Actually load the image file we previously decided to load.
1345 	 */
1346 	lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1347 	if (lret != LOAD_SUCCESS) {
1348 		error = load_return_to_errno(lret);
1349 
1350 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1351 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1352 		if (lret == LOAD_BADMACHO_UPX) {
1353 			set_proc_name(imgp, p);
1354 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1355 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1356 		} else {
1357 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1358 
1359 			if (bootarg_execfailurereports) {
1360 				set_proc_name(imgp, p);
1361 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1362 			}
1363 		}
1364 
1365 		exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1366 
1367 		goto badtoolate;
1368 	}
1369 
1370 	/*
1371 	 * ERROR RECOVERY
1372 	 *
1373 	 * load_machfile() returned the new VM map ("map") but we haven't
1374 	 * committed to it yet.
1375 	 * Any error path between here and the point where we commit to using
1376 	 * the new "map" (with swap_task_map()) should deallocate "map".
1377 	 */
1378 
1379 #ifndef KASAN
1380 	/*
1381 	 * Security: zone sanity checks on fresh boot or initproc re-exec.
1382 	 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1383 	 * which means here is the earliest point we can assert on empty service port label zone,
1384 	 * after load_machfile() above terminates old launchd's IPC space.
1385 	 *
1386 	 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1387 	 * under quarantine.
1388 	 */
1389 	if (task_pid(task) == 1) {
1390 		zone_userspace_reboot_checks();
1391 	}
1392 #endif
1393 
1394 	proc_lock(p);
1395 	p->p_cputype = imgp->ip_origcputype;
1396 	p->p_cpusubtype = imgp->ip_origcpusubtype;
1397 	proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1398 	exec_setup_tpro(imgp, &load_result);
1399 
1400 	vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1401 	vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1402 	vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1403 #if XNU_TARGET_OS_OSX
1404 	if (proc_platform(p) == PLATFORM_IOS) {
1405 		assert(vm_map_is_alien(map));
1406 	} else {
1407 		assert(!vm_map_is_alien(map));
1408 	}
1409 #endif /* XNU_TARGET_OS_OSX */
1410 	proc_unlock(p);
1411 
1412 	/*
1413 	 * Set TPRO flags if enabled
1414 	 */
1415 
1416 	/*
1417 	 * Set code-signing flags if this binary is signed, or if parent has
1418 	 * requested them on exec.
1419 	 */
1420 	if (load_result.csflags & CS_VALID) {
1421 		imgp->ip_csflags |= load_result.csflags &
1422 		    (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1423 		    CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1424 		    CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1425 		    CS_ENTITLEMENT_FLAGS |
1426 		    CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1427 	} else {
1428 		imgp->ip_csflags &= ~CS_VALID;
1429 	}
1430 
1431 	if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1432 		imgp->ip_csflags |= CS_HARD;
1433 	}
1434 	if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1435 		imgp->ip_csflags |= CS_KILL;
1436 	}
1437 	if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1438 		imgp->ip_csflags |= CS_ENFORCEMENT;
1439 	}
1440 	if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1441 		if (proc_getcsflags(p) & CS_INSTALLER) {
1442 			imgp->ip_csflags |= CS_INSTALLER;
1443 		}
1444 		if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1445 			imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1446 		}
1447 		if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1448 			imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1449 		}
1450 	}
1451 
1452 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1453 	/*
1454 	 * ptrauth version 0 is a preview ABI.  Developers can opt into running
1455 	 * their own arm64e binaries for local testing, with the understanding
1456 	 * that future OSes may break ABI.
1457 	 */
1458 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1459 	    CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1460 	    !load_result.platform_binary &&
1461 	    !bootarg_arm64e_preview_abi) {
1462 		static bool logged_once = false;
1463 		set_proc_name(imgp, p);
1464 
1465 		printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1466 		if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1467 			printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1468 		}
1469 
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 
1482 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1483 	    imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1484 	    load_result.platform_binary &&
1485 	    (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1486 		set_proc_name(imgp, p);
1487 		printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
1488 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1489 		if (bootarg_execfailurereports) {
1490 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1491 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1492 		}
1493 
1494 		/* release new address space since we won't use it */
1495 		imgp->ip_free_map = map;
1496 		map = VM_MAP_NULL;
1497 		goto badtoolate;
1498 	}
1499 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1500 
1501 
1502 	load_result.hardened_runtime_binary = 0;
1503 	// Propogate which hardened runtime entitlements are active to the apple array
1504 	encode_HR_entitlement(kCSWebBrowserHostEntitlement, BrowserHostEntitlementMask, imgp, &load_result);
1505 	encode_HR_entitlement(kCSWebBrowserGPUEntitlement, BrowserGPUEntitlementMask, imgp, &load_result);
1506 	encode_HR_entitlement(kCSWebBrowserNetworkEntitlement, BrowserNetworkEntitlementMask, imgp, &load_result);
1507 	encode_HR_entitlement(kCSWebBrowserWebContentEntitlement, BrowserWebContentEntitlementMask, imgp, &load_result);
1508 
1509 	/*
1510 	 * Set up the shared cache region in the new process.
1511 	 *
1512 	 * Normally there is a single shared region per architecture.
1513 	 * However on systems with Pointer Authentication, we can create
1514 	 * multiple shared caches with the amount of sharing determined
1515 	 * by team-id or entitlement. Inherited shared region IDs are used
1516 	 * for system processes that need to match and be able to inspect
1517 	 * a pre-existing task.
1518 	 */
1519 	int cpu_subtype = 0; /* all cpu_subtypes use the same shared region */
1520 #if __has_feature(ptrauth_calls)
1521 	char *shared_region_id = NULL;
1522 	size_t len;
1523 	char *base;
1524 	const char *cbase;
1525 #define HARDENED_RUNTIME_CONTENT_ID "C-"
1526 #define TEAM_ID_PREFIX "T-"
1527 #define ENTITLE_PREFIX "E-"
1528 #define SR_PREFIX_LEN  2
1529 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1530 
1531 	if (cpu_type() == CPU_TYPE_ARM64 &&
1532 	    arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1533 	    (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1534 		assertf(p->p_cputype == CPU_TYPE_ARM64,
1535 		    "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1536 		    p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1537 
1538 		/*
1539 		 * arm64e uses pointer authentication, so request a separate
1540 		 * shared region for this CPU subtype.
1541 		 */
1542 		cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1543 
1544 		/*
1545 		 * Determine which shared cache to select based on being told,
1546 		 * matching a team-id or matching an entitlement.
1547 		 */
1548 		if (load_result.hardened_runtime_binary & BrowserWebContentEntitlementMask) {
1549 			len = sizeof(HARDENED_RUNTIME_CONTENT_ID);
1550 			shared_region_id = kalloc_data(len, Z_WAITOK | Z_NOFAIL);
1551 			strlcpy(shared_region_id, HARDENED_RUNTIME_CONTENT_ID, len);
1552 		} else if (imgp->ip_inherited_shared_region_id) {
1553 			len = strlen(imgp->ip_inherited_shared_region_id);
1554 			shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1555 			memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1556 		} else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1557 			len = strlen(cbase);
1558 			if (vm_shared_region_per_team_id) {
1559 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1560 				    Z_WAITOK | Z_NOFAIL);
1561 				memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1562 				memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1563 			}
1564 		} else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1565 		    (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1566 			len = strlen(base);
1567 			if (vm_shared_region_by_entitlement) {
1568 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1569 				    Z_WAITOK | Z_NOFAIL);
1570 				memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1571 				memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1572 			}
1573 			/* Discard the copy of the entitlement */
1574 			kfree_data(base, len + 1);
1575 		}
1576 	}
1577 
1578 	if (imgp->ip_flags & IMGPF_RESLIDE) {
1579 		reslide = TRUE;
1580 	}
1581 
1582 	/* use "" as the default shared_region_id */
1583 	if (shared_region_id == NULL) {
1584 		shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1585 	}
1586 
1587 	/* ensure there's a unique pointer signing key for this shared_region_id */
1588 	shared_region_key_alloc(shared_region_id,
1589 	    imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1590 	task_set_shared_region_id(task, shared_region_id);
1591 	shared_region_id = NULL;
1592 #endif /* __has_feature(ptrauth_calls) */
1593 
1594 #if CONFIG_ROSETTA
1595 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1596 		OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
1597 	} else if (p->p_flag & P_TRANSLATED) {
1598 		OSBitAndAtomic(~P_TRANSLATED, &p->p_flag);
1599 	}
1600 #endif
1601 
1602 	int cputype = cpu_type();
1603 
1604 	uint32_t rsr_version = 0;
1605 #if XNU_TARGET_OS_OSX
1606 	if (vnode_is_rsr(imgp->ip_vp)) {
1607 		rsr_version = rsr_get_version();
1608 		os_atomic_or(&p->p_ladvflag, P_RSR, relaxed);
1609 		os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_ALTLINK, relaxed);
1610 	}
1611 #endif /* XNU_TARGET_OS_OSX */
1612 
1613 	vm_map_exec(map, task, load_result.is_64bit_addr,
1614 	    (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide,
1615 	    (imgp->ip_flags & IMGPF_DRIVER) != 0,
1616 	    rsr_version);
1617 
1618 	/*
1619 	 * Close file descriptors which specify close-on-exec.
1620 	 */
1621 	fdt_exec(p, vfs_context_ucred(imgp->ip_vfs_context),
1622 	    psa != NULL ? psa->psa_flags : 0, imgp->ip_new_thread, exec);
1623 
1624 	/*
1625 	 * deal with set[ug]id.
1626 	 */
1627 	error = exec_handle_sugid(imgp);
1628 	if (error) {
1629 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1630 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1631 
1632 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1633 		if (bootarg_execfailurereports) {
1634 			set_proc_name(imgp, p);
1635 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1636 		}
1637 
1638 		/* release new address space since we won't use it */
1639 		imgp->ip_free_map = map;
1640 		map = VM_MAP_NULL;
1641 		goto badtoolate;
1642 	}
1643 
1644 	/*
1645 	 * Commit to new map.
1646 	 *
1647 	 * Swap the new map for the old for target task, which consumes
1648 	 * our new map reference but each leaves us responsible for the
1649 	 * old_map reference.  That lets us get off the pmap associated
1650 	 * with it, and then we can release it.
1651 	 *
1652 	 * The map needs to be set on the target task which is different
1653 	 * than current task, thus swap_task_map is used instead of
1654 	 * vm_map_switch.
1655 	 */
1656 	old_map = swap_task_map(task, thread, map);
1657 #if MACH_ASSERT
1658 	/*
1659 	 * Reset the pmap's process info to prevent ledger checks
1660 	 * which might fail due to the ledgers being shared between
1661 	 * the old and new pmaps.
1662 	 */
1663 	vm_map_pmap_set_process(old_map, -1, "<old_map>");
1664 #endif /* MACH_ASSERT */
1665 	imgp->ip_free_map = old_map;
1666 	old_map = NULL;
1667 
1668 	lret = activate_exec_state(task, p, thread, &load_result);
1669 	if (lret != KERN_SUCCESS) {
1670 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1671 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1672 
1673 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1674 		if (bootarg_execfailurereports) {
1675 			set_proc_name(imgp, p);
1676 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1677 		}
1678 
1679 		goto badtoolate;
1680 	}
1681 
1682 	/*
1683 	 * deal with voucher on exec-calling thread.
1684 	 */
1685 	if (imgp->ip_new_thread == NULL) {
1686 		thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1687 	}
1688 
1689 	/* Make sure we won't interrupt ourself signalling a partial process */
1690 	if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1691 		psignal(p, SIGTRAP);
1692 	}
1693 
1694 	if (load_result.unixproc &&
1695 	    create_unix_stack(get_task_map(task),
1696 	    &load_result,
1697 	    p) != KERN_SUCCESS) {
1698 		error = load_return_to_errno(LOAD_NOSPACE);
1699 
1700 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1701 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1702 
1703 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1704 		if (bootarg_execfailurereports) {
1705 			set_proc_name(imgp, p);
1706 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1707 		}
1708 
1709 		goto badtoolate;
1710 	}
1711 
1712 	if (load_result.hardened_runtime_binary) {
1713 		if (cs_debug) {
1714 			printf("setting hardened runtime with entitlement mask= "
1715 			    "0x%x on task: pid = %d\n",
1716 			    load_result.hardened_runtime_binary,
1717 			    proc_getpid(p));
1718 		}
1719 		task_set_hardened_runtime(task, true);
1720 	}
1721 
1722 	/*
1723 	 * The load result will have already been munged by AMFI to include the
1724 	 * platform binary flag if boot-args dictated it (AMFI will mark anything
1725 	 * that doesn't go through the upcall path as a platform binary if its
1726 	 * enforcement is disabled).
1727 	 */
1728 	if (load_result.platform_binary) {
1729 		if (cs_debug) {
1730 			printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1731 		}
1732 
1733 		/*
1734 		 * We must use 'task' here because the proc's task has not yet been
1735 		 * switched to the new one.
1736 		 */
1737 		task_set_platform_binary(task, TRUE);
1738 	} else {
1739 		if (cs_debug) {
1740 			printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1741 		}
1742 
1743 		task_set_platform_binary(task, FALSE);
1744 	}
1745 
1746 #if XNU_TARGET_OS_OSX
1747 	/* Disable mach hardening for all 1P tasks which load 3P plugins */
1748 	if (imgp->ip_flags & IMGPF_3P_PLUGINS) {
1749 		if (cs_debug) {
1750 			printf("Disabling some mach hardening on task due to 3P plugins: pid = %d\n", proc_getpid(p));
1751 		}
1752 		task_disable_mach_hardening(task);
1753 	}
1754 #if DEVELOPMENT || DEBUG
1755 	/* Disable mach hardening for all tasks if amfi_get_out_of_my_way is set.
1756 	 * Customers will have to turn SIP off to use this boot-arg, and so this is
1757 	 * only needed internally since we disable this feature when SIP is off. */
1758 	if (AMFI_bootarg_disable_mach_hardening) {
1759 		if (cs_debug) {
1760 			printf("Disabling some mach hardening on task due to AMFI boot-args: pid = %d\n", proc_getpid(p));
1761 		}
1762 		task_disable_mach_hardening(task);
1763 	}
1764 #endif /* DEVELOPMENT || DEBUG */
1765 #endif /* XNU_TARGET_OS_OSX */
1766 
1767 	/*
1768 	 * Set starting EXC_GUARD and control port behavior for task now that
1769 	 * platform and hardened runtime is set. Use the name directly from imgp since we haven't
1770 	 * set_proc_name() yet. Also make control port for the task and main thread
1771 	 * immovable/pinned based on task's option.
1772 	 *
1773 	 * Must happen before main thread port copyout in exc_add_apple_strings.
1774 	 */
1775 	task_set_exc_guard_ctrl_port_default(task, thread,
1776 	    imgp->ip_ndp->ni_cnd.cn_nameptr,
1777 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1778 	    proc_is_simulated(p),
1779 	    load_result.ip_platform,
1780 	    load_result.lr_sdk);
1781 
1782 	error = exec_add_apple_strings(imgp, &load_result); /* copies out main thread port */
1783 
1784 	if (error) {
1785 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1786 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
1787 
1788 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
1789 		if (bootarg_execfailurereports) {
1790 			set_proc_name(imgp, p);
1791 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1792 		}
1793 		goto badtoolate;
1794 	}
1795 
1796 	/* Switch to target task's map to copy out strings */
1797 	old_map = vm_map_switch(get_task_map(task));
1798 
1799 	if (load_result.unixproc) {
1800 		user_addr_t     ap;
1801 
1802 		/*
1803 		 * Copy the strings area out into the new process address
1804 		 * space.
1805 		 */
1806 		ap = p->user_stack;
1807 		error = exec_copyout_strings(imgp, &ap);
1808 		if (error) {
1809 			vm_map_switch(old_map);
1810 
1811 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1812 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
1813 
1814 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
1815 			if (bootarg_execfailurereports) {
1816 				set_proc_name(imgp, p);
1817 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1818 			}
1819 			goto badtoolate;
1820 		}
1821 		/* Set the stack */
1822 		thread_setuserstack(thread, ap);
1823 	}
1824 
1825 	if (load_result.dynlinker || load_result.is_rosetta) {
1826 		user_addr_t        ap;
1827 		int                     new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
1828 
1829 		/* Adjust the stack */
1830 		ap = thread_adjuserstack(thread, -new_ptr_size);
1831 		error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
1832 
1833 		if (error) {
1834 			vm_map_switch(old_map);
1835 
1836 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1837 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
1838 
1839 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
1840 			if (bootarg_execfailurereports) {
1841 				set_proc_name(imgp, p);
1842 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1843 			}
1844 			goto badtoolate;
1845 		}
1846 		error = task_set_dyld_info(task, load_result.all_image_info_addr,
1847 		    load_result.all_image_info_size);
1848 		if (error) {
1849 			vm_map_switch(old_map);
1850 
1851 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1852 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
1853 
1854 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1855 			if (bootarg_execfailurereports) {
1856 				set_proc_name(imgp, p);
1857 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1858 			}
1859 			error = EINVAL;
1860 			goto badtoolate;
1861 		}
1862 	}
1863 
1864 #if CONFIG_ROSETTA
1865 	if (load_result.is_rosetta) {
1866 		// Add an fd for the executable file for Rosetta's use
1867 		int main_binary_fd;
1868 		struct fileproc *fp;
1869 
1870 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &main_binary_fd);
1871 		if (error) {
1872 			vm_map_switch(old_map);
1873 
1874 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1875 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1876 
1877 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1878 			if (bootarg_execfailurereports) {
1879 				set_proc_name(imgp, p);
1880 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1881 			}
1882 			goto badtoolate;
1883 		}
1884 
1885 		error = VNOP_OPEN(imgp->ip_vp, FREAD, imgp->ip_vfs_context);
1886 		if (error) {
1887 			vm_map_switch(old_map);
1888 
1889 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1890 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1891 
1892 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1893 			if (bootarg_execfailurereports) {
1894 				set_proc_name(imgp, p);
1895 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1896 			}
1897 			goto cleanup_rosetta_fp;
1898 		}
1899 
1900 		fp->fp_glob->fg_flag = FREAD;
1901 		fp->fp_glob->fg_ops = &vnops;
1902 		fp_set_data(fp, imgp->ip_vp);
1903 
1904 		proc_fdlock(p);
1905 		procfdtbl_releasefd(p, main_binary_fd, NULL);
1906 		fp_drop(p, main_binary_fd, fp, 1);
1907 		proc_fdunlock(p);
1908 
1909 		vnode_ref(imgp->ip_vp);
1910 
1911 		// Pass the dyld load address, main binary fd, and dyld fd on the stack
1912 		uint64_t ap = thread_adjuserstack(thread, -24);
1913 
1914 		error = copyoutptr((user_addr_t)load_result.dynlinker_fd, ap, 8);
1915 		if (error) {
1916 			vm_map_switch(old_map);
1917 
1918 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1919 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1920 
1921 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1922 			if (bootarg_execfailurereports) {
1923 				set_proc_name(imgp, p);
1924 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1925 			}
1926 			goto cleanup_rosetta_fp;
1927 		}
1928 
1929 		error = copyoutptr(load_result.dynlinker_mach_header, ap + 8, 8);
1930 		if (error) {
1931 			vm_map_switch(old_map);
1932 
1933 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1934 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1935 
1936 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1937 			if (bootarg_execfailurereports) {
1938 				set_proc_name(imgp, p);
1939 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1940 			}
1941 			goto cleanup_rosetta_fp;
1942 		}
1943 
1944 		error = copyoutptr((user_addr_t)main_binary_fd, ap + 16, 8);
1945 		if (error) {
1946 			vm_map_switch(old_map);
1947 
1948 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1949 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1950 
1951 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1952 			if (bootarg_execfailurereports) {
1953 				set_proc_name(imgp, p);
1954 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1955 			}
1956 			goto cleanup_rosetta_fp;
1957 		}
1958 
1959 cleanup_rosetta_fp:
1960 		if (error) {
1961 			fp_free(p, load_result.dynlinker_fd, load_result.dynlinker_fp);
1962 			fp_free(p, main_binary_fd, fp);
1963 			goto badtoolate;
1964 		}
1965 	}
1966 
1967 #endif
1968 
1969 	/* Avoid immediate VM faults back into kernel */
1970 	exec_prefault_data(p, imgp, &load_result);
1971 
1972 	vm_map_switch(old_map);
1973 
1974 	/*
1975 	 * Reset signal state.
1976 	 */
1977 	execsigs(p, thread);
1978 
1979 	/*
1980 	 * need to cancel async IO requests that can be cancelled and wait for those
1981 	 * already active.  MAY BLOCK!
1982 	 */
1983 	_aio_exec( p );
1984 
1985 #if SYSV_SHM
1986 	/* FIXME: Till vmspace inherit is fixed: */
1987 	if (!vfexec && p->vm_shm) {
1988 		shmexec(p);
1989 	}
1990 #endif
1991 #if SYSV_SEM
1992 	/* Clean up the semaphores */
1993 	semexit(p);
1994 #endif
1995 
1996 	/*
1997 	 * Remember file name for accounting.
1998 	 */
1999 	p->p_acflag &= ~AFORK;
2000 
2001 	set_proc_name(imgp, p);
2002 
2003 #if CONFIG_SECLUDED_MEMORY
2004 	if (secluded_for_apps &&
2005 	    load_result.platform_binary) {
2006 		if (strncmp(p->p_name,
2007 		    "Camera",
2008 		    sizeof(p->p_name)) == 0) {
2009 			task_set_could_use_secluded_mem(task, TRUE);
2010 		} else {
2011 			task_set_could_use_secluded_mem(task, FALSE);
2012 		}
2013 		if (strncmp(p->p_name,
2014 		    "mediaserverd",
2015 		    sizeof(p->p_name)) == 0) {
2016 			task_set_could_also_use_secluded_mem(task, TRUE);
2017 		}
2018 	}
2019 #endif /* CONFIG_SECLUDED_MEMORY */
2020 
2021 #if __arm64__
2022 	if (load_result.legacy_footprint) {
2023 		task_set_legacy_footprint(task);
2024 	}
2025 #endif /* __arm64__ */
2026 
2027 	pal_dbg_set_task_name(task);
2028 
2029 #if DEVELOPMENT || DEBUG
2030 	/*
2031 	 * Update the pid an proc name for importance base if any
2032 	 */
2033 	task_importance_update_owner_info(task);
2034 #endif
2035 
2036 	proc_setexecutableuuid(p, &load_result.uuid[0]);
2037 
2038 #if CONFIG_DTRACE
2039 	dtrace_proc_exec(p);
2040 #endif
2041 
2042 	if (kdebug_enable) {
2043 		long args[4] = {};
2044 
2045 		uintptr_t fsid = 0, fileid = 0;
2046 		if (imgp->ip_vattr) {
2047 			uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
2048 			fsid   = (uintptr_t)fsid64;
2049 			fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
2050 			// check for (unexpected) overflow and trace zero in that case
2051 			if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
2052 				fsid = fileid = 0;
2053 			}
2054 		}
2055 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
2056 		    (uintptr_t)thread_tid(thread));
2057 
2058 		extern void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
2059 		kdebug_proc_name_args(p, args);
2060 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
2061 		    args[2], args[3], (uintptr_t)thread_tid(thread));
2062 	}
2063 
2064 
2065 	/*
2066 	 * If posix_spawned with the START_SUSPENDED flag, stop the
2067 	 * process before it runs.
2068 	 */
2069 	if (imgp->ip_px_sa != NULL) {
2070 		psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
2071 		if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
2072 			proc_lock(p);
2073 			p->p_stat = SSTOP;
2074 			proc_unlock(p);
2075 			(void) task_suspend_internal(task);
2076 		}
2077 	}
2078 
2079 	/*
2080 	 * mark as execed
2081 	 */
2082 	OSBitOrAtomic(P_EXEC, &p->p_flag);
2083 	proc_resetregister(p);
2084 	if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
2085 		proc_lock(p);
2086 		p->p_lflag &= ~P_LPPWAIT;
2087 		proc_unlock(p);
2088 		wakeup((caddr_t)p->p_pptr);
2089 	}
2090 
2091 	/*
2092 	 * Set up dext coredumps on kernel panic.
2093 	 * This requires the following:
2094 	 * - dext_panic_coredump=1 boot-arg (enabled by default on DEVELOPMENT, DEBUG and certain Seed builds)
2095 	 * - process must be a driver
2096 	 * - process must have the com.apple.private.enable-coredump-on-panic entitlement, and the
2097 	 *   entitlement has a string value.
2098 	 * - process must have the com.apple.private.enable-coredump-on-panic-seed-privacy-approved
2099 	 *   entitlement (Seed builds only).
2100 	 *
2101 	 * The core dump file name is formatted with the entitlement string value, followed by a hyphen
2102 	 * and the process PID.
2103 	 */
2104 	if (enable_dext_coredumps_on_panic &&
2105 	    (imgp->ip_flags & IMGPF_DRIVER) != 0 &&
2106 	    (userspace_coredump_name = IOVnodeGetEntitlement(imgp->ip_vp,
2107 	    (int64_t)imgp->ip_arch_offset, USERSPACE_COREDUMP_PANIC_ENTITLEMENT)) != NULL) {
2108 		size_t userspace_coredump_name_len = strlen(userspace_coredump_name);
2109 
2110 		char core_name[MACH_CORE_FILEHEADER_NAMELEN];
2111 		/* 16 - NULL char - strlen("-") - maximum of 5 digits for pid */
2112 		snprintf(core_name, MACH_CORE_FILEHEADER_NAMELEN, "%.9s-%d", userspace_coredump_name, proc_getpid(p));
2113 
2114 		kern_register_userspace_coredump(task, core_name);
2115 
2116 		/* Discard the copy of the entitlement */
2117 		kfree_data(userspace_coredump_name, userspace_coredump_name_len + 1);
2118 		userspace_coredump_name = NULL;
2119 	}
2120 
2121 	goto done;
2122 
2123 badtoolate:
2124 	/* Don't allow child process to execute any instructions */
2125 	if (!spawn) {
2126 		{
2127 			assert(exec_failure_reason != OS_REASON_NULL);
2128 			if (bootarg_execfailurereports) {
2129 				set_proc_name(imgp, current_proc());
2130 			}
2131 			psignal_with_reason(current_proc(), SIGKILL, exec_failure_reason);
2132 			exec_failure_reason = OS_REASON_NULL;
2133 
2134 			if (exec) {
2135 				/* Terminate the exec copy task */
2136 				task_terminate_internal(task);
2137 			}
2138 		}
2139 
2140 		/* We can't stop this system call at this point, so just pretend we succeeded */
2141 		error = 0;
2142 	} else {
2143 		os_reason_free(exec_failure_reason);
2144 		exec_failure_reason = OS_REASON_NULL;
2145 	}
2146 
2147 done:
2148 	if (load_result.threadstate) {
2149 		kfree_data(load_result.threadstate, load_result.threadstate_sz);
2150 		load_result.threadstate = NULL;
2151 	}
2152 
2153 bad:
2154 	/* If we hit this, we likely would have leaked an exit reason */
2155 	assert(exec_failure_reason == OS_REASON_NULL);
2156 	return error;
2157 }
2158 
2159 
2160 
2161 
2162 /*
2163  * Our image activator table; this is the table of the image types we are
2164  * capable of loading.  We list them in order of preference to ensure the
2165  * fastest image load speed.
2166  *
2167  * XXX hardcoded, for now; should use linker sets
2168  */
2169 struct execsw {
2170 	int(*const ex_imgact)(struct image_params *);
2171 	const char *ex_name;
2172 }const execsw[] = {
2173 	{ exec_mach_imgact, "Mach-o Binary" },
2174 	{ exec_fat_imgact, "Fat Binary" },
2175 	{ exec_shell_imgact, "Interpreter Script" },
2176 	{ NULL, NULL}
2177 };
2178 
2179 
2180 /*
2181  * exec_activate_image
2182  *
2183  * Description:	Iterate through the available image activators, and activate
2184  *		the image associated with the imgp structure.  We start with
2185  *		the activator for Mach-o binaries followed by that for Fat binaries
2186  *		for Interpreter scripts.
2187  *
2188  * Parameters:	struct image_params *	Image parameter block
2189  *
2190  * Returns:	0			Success
2191  *		ENOEXEC			No activator for image.
2192  *		EBADEXEC		The executable is corrupt/unknown
2193  *	execargs_alloc:EINVAL		Invalid argument
2194  *	execargs_alloc:EACCES		Permission denied
2195  *	execargs_alloc:EINTR		Interrupted function
2196  *	execargs_alloc:ENOMEM		Not enough space
2197  *	exec_save_path:EFAULT		Bad address
2198  *	exec_save_path:ENAMETOOLONG	Filename too long
2199  *	exec_check_permissions:EACCES	Permission denied
2200  *	exec_check_permissions:ENOEXEC	Executable file format error
2201  *	exec_check_permissions:ETXTBSY	Text file busy [misuse of error code]
2202  *	exec_check_permissions:???
2203  *	namei:???
2204  *	vn_rdwr:???			[anything vn_rdwr can return]
2205  *	<ex_imgact>:???			[anything an imgact can return]
2206  *	EDEADLK				Process is being terminated
2207  */
2208 static int
exec_activate_image(struct image_params * imgp)2209 exec_activate_image(struct image_params *imgp)
2210 {
2211 	struct nameidata *ndp = NULL;
2212 	const char *excpath;
2213 	int error;
2214 	int resid;
2215 	int once = 1;   /* save SGUID-ness for interpreted files */
2216 	int i;
2217 	int itercount = 0;
2218 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2219 
2220 	/*
2221 	 * For exec, the translock needs to be taken on old proc and not
2222 	 * on new shadow proc.
2223 	 */
2224 	if (imgp->ip_flags & IMGPF_EXEC) {
2225 		p = current_proc();
2226 	}
2227 
2228 	error = execargs_alloc(imgp);
2229 	if (error) {
2230 		goto bad_notrans;
2231 	}
2232 
2233 	error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
2234 	if (error) {
2235 		goto bad_notrans;
2236 	}
2237 
2238 	/* Use excpath, which contains the copyin-ed exec path */
2239 	DTRACE_PROC1(exec, uintptr_t, excpath);
2240 
2241 	ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2242 
2243 	NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
2244 	    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2245 
2246 again:
2247 	error = namei(ndp);
2248 	if (error) {
2249 		if (error == ERESTART) {
2250 			error = EINTR;
2251 		}
2252 		goto bad_notrans;
2253 	}
2254 	imgp->ip_ndp = ndp;     /* successful namei(); call nameidone() later */
2255 	imgp->ip_vp = ndp->ni_vp;       /* if set, need to vnode_put() at some point */
2256 
2257 	/*
2258 	 * Before we start the transition from binary A to binary B, make
2259 	 * sure another thread hasn't started exiting the process.  We grab
2260 	 * the proc lock to check p_lflag initially, and the transition
2261 	 * mechanism ensures that the value doesn't change after we release
2262 	 * the lock.
2263 	 */
2264 	proc_lock(p);
2265 	if (p->p_lflag & P_LEXIT) {
2266 		error = EDEADLK;
2267 		proc_unlock(p);
2268 		goto bad_notrans;
2269 	}
2270 	error = proc_transstart(p, 1, 0);
2271 	proc_unlock(p);
2272 	if (error) {
2273 		goto bad_notrans;
2274 	}
2275 
2276 	error = exec_check_permissions(imgp);
2277 	if (error) {
2278 		goto bad;
2279 	}
2280 
2281 	/* Copy; avoid invocation of an interpreter overwriting the original */
2282 	if (once) {
2283 		once = 0;
2284 		*imgp->ip_origvattr = *imgp->ip_vattr;
2285 	}
2286 
2287 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
2288 	    UIO_SYSSPACE, IO_NODELOCKED,
2289 	    vfs_context_ucred(imgp->ip_vfs_context),
2290 	    &resid, vfs_context_proc(imgp->ip_vfs_context));
2291 	if (error) {
2292 		goto bad;
2293 	}
2294 
2295 	if (resid) {
2296 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
2297 	}
2298 
2299 encapsulated_binary:
2300 	/* Limit the number of iterations we will attempt on each binary */
2301 	if (++itercount > EAI_ITERLIMIT) {
2302 		error = EBADEXEC;
2303 		goto bad;
2304 	}
2305 	error = -1;
2306 	for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
2307 		error = (*execsw[i].ex_imgact)(imgp);
2308 
2309 		switch (error) {
2310 		/* case -1: not claimed: continue */
2311 		case -2:                /* Encapsulated binary, imgp->ip_XXX set for next iteration */
2312 			goto encapsulated_binary;
2313 
2314 		case -3:                /* Interpreter */
2315 #if CONFIG_MACF
2316 			/*
2317 			 * Copy the script label for later use. Note that
2318 			 * the label can be different when the script is
2319 			 * actually read by the interpreter.
2320 			 */
2321 			if (imgp->ip_scriptlabelp) {
2322 				mac_vnode_label_free(imgp->ip_scriptlabelp);
2323 				imgp->ip_scriptlabelp = NULL;
2324 			}
2325 			imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
2326 			if (imgp->ip_scriptlabelp == NULL) {
2327 				error = ENOMEM;
2328 				break;
2329 			}
2330 			mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
2331 			    imgp->ip_scriptlabelp);
2332 
2333 			/*
2334 			 * Take a ref of the script vnode for later use.
2335 			 */
2336 			if (imgp->ip_scriptvp) {
2337 				vnode_put(imgp->ip_scriptvp);
2338 				imgp->ip_scriptvp = NULLVP;
2339 			}
2340 			if (vnode_getwithref(imgp->ip_vp) == 0) {
2341 				imgp->ip_scriptvp = imgp->ip_vp;
2342 			}
2343 #endif
2344 
2345 			nameidone(ndp);
2346 
2347 			vnode_put(imgp->ip_vp);
2348 			imgp->ip_vp = NULL;     /* already put */
2349 			imgp->ip_ndp = NULL; /* already nameidone */
2350 
2351 			/* Use excpath, which exec_shell_imgact reset to the interpreter */
2352 			NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
2353 			    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2354 
2355 			proc_transend(p, 0);
2356 			goto again;
2357 
2358 		default:
2359 			break;
2360 		}
2361 	}
2362 
2363 	if (error == -1) {
2364 		error = ENOEXEC;
2365 	} else if (error == 0) {
2366 		if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
2367 			AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
2368 		}
2369 
2370 		/*
2371 		 * Call out to allow 3rd party notification of exec.
2372 		 * Ignore result of kauth_authorize_fileop call.
2373 		 */
2374 		if (kauth_authorize_fileop_has_listeners()) {
2375 			kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
2376 			    KAUTH_FILEOP_EXEC,
2377 			    (uintptr_t)ndp->ni_vp, 0);
2378 		}
2379 	}
2380 bad:
2381 	proc_transend(p, 0);
2382 
2383 bad_notrans:
2384 	if (imgp->ip_strings) {
2385 		execargs_free(imgp);
2386 	}
2387 	if (imgp->ip_ndp) {
2388 		nameidone(imgp->ip_ndp);
2389 	}
2390 	kfree_type(struct nameidata, ndp);
2391 
2392 	return error;
2393 }
2394 
2395 /*
2396  * exec_validate_spawnattr_policy
2397  *
2398  * Description: Validates the entitlements required to set the apptype.
2399  *
2400  * Parameters:  int psa_apptype         posix spawn attribute apptype
2401  *
2402  * Returns:     0                       Success
2403  *              EPERM                   Failure
2404  */
2405 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)2406 exec_validate_spawnattr_policy(int psa_apptype)
2407 {
2408 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2409 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2410 		if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
2411 			if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
2412 				return EPERM;
2413 			}
2414 		}
2415 	}
2416 
2417 	return 0;
2418 }
2419 
2420 /*
2421  * exec_handle_spawnattr_policy
2422  *
2423  * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
2424  *
2425  * Parameters:  proc_t p                process to apply attributes to
2426  *              int psa_apptype         posix spawn attribute apptype
2427  *
2428  * Returns:     0                       Success
2429  */
2430 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)2431 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2432     task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2433 {
2434 	int apptype     = TASK_APPTYPE_NONE;
2435 	int qos_clamp   = THREAD_QOS_UNSPECIFIED;
2436 	task_role_t role = TASK_UNSPECIFIED;
2437 
2438 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2439 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2440 
2441 		switch (proctype) {
2442 		case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2443 			apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2444 			break;
2445 		case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2446 			apptype = TASK_APPTYPE_DAEMON_STANDARD;
2447 			break;
2448 		case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2449 			apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2450 			break;
2451 		case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2452 			apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2453 			break;
2454 		case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2455 			apptype = TASK_APPTYPE_APP_DEFAULT;
2456 			break;
2457 		case POSIX_SPAWN_PROC_TYPE_DRIVER:
2458 			apptype = TASK_APPTYPE_DRIVER;
2459 			break;
2460 		default:
2461 			apptype = TASK_APPTYPE_NONE;
2462 			/* TODO: Should an invalid value here fail the spawn? */
2463 			break;
2464 		}
2465 	}
2466 
2467 	if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2468 		switch (psa_qos_clamp) {
2469 		case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2470 			qos_clamp = THREAD_QOS_UTILITY;
2471 			break;
2472 		case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2473 			qos_clamp = THREAD_QOS_BACKGROUND;
2474 			break;
2475 		case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2476 			qos_clamp = THREAD_QOS_MAINTENANCE;
2477 			break;
2478 		default:
2479 			qos_clamp = THREAD_QOS_UNSPECIFIED;
2480 			/* TODO: Should an invalid value here fail the spawn? */
2481 			break;
2482 		}
2483 	}
2484 
2485 	if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2486 		proc_darwin_role_to_task_role(psa_darwin_role, &role);
2487 	}
2488 
2489 	if (apptype != TASK_APPTYPE_NONE ||
2490 	    qos_clamp != THREAD_QOS_UNSPECIFIED ||
2491 	    role != TASK_UNSPECIFIED ||
2492 	    port_actions->portwatch_count) {
2493 		proc_set_task_spawnpolicy(proc_task(p), thread, apptype, qos_clamp, role,
2494 		    port_actions->portwatch_array, port_actions->portwatch_count);
2495 	}
2496 
2497 	if (port_actions->registered_count) {
2498 		if (_kernelrpc_mach_ports_register3(proc_task(p),
2499 		    port_actions->registered_array[0],
2500 		    port_actions->registered_array[1],
2501 		    port_actions->registered_array[2])) {
2502 			return EINVAL;
2503 		}
2504 		/* mach_ports_register() consumed the array */
2505 		bzero(port_actions->registered_array,
2506 		    sizeof(port_actions->registered_array));
2507 		port_actions->registered_count = 0;
2508 	}
2509 
2510 	return 0;
2511 }
2512 
2513 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2514 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2515 {
2516 	if (port_actions->excport_array) {
2517 		for (uint32_t i = 0; i < port_actions->exception_port_count; i++) {
2518 			ipc_port_t port = NULL;
2519 			if ((port = port_actions->excport_array[i].port) != NULL) {
2520 				ipc_port_release_send(port);
2521 			}
2522 		}
2523 		kfree_type(struct exception_port_action_t, port_actions->exception_port_count,
2524 		    port_actions->excport_array);
2525 	}
2526 
2527 	if (port_actions->portwatch_array) {
2528 		for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2529 			ipc_port_t port = NULL;
2530 			if ((port = port_actions->portwatch_array[i]) != NULL) {
2531 				ipc_port_release_send(port);
2532 			}
2533 		}
2534 		kfree_type(ipc_port_t, port_actions->portwatch_count,
2535 		    port_actions->portwatch_array);
2536 	}
2537 
2538 	for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2539 		ipc_port_t port = NULL;
2540 		if ((port = port_actions->registered_array[i]) != NULL) {
2541 			ipc_port_release_send(port);
2542 		}
2543 	}
2544 }
2545 
2546 /*
2547  * exec_handle_port_actions
2548  *
2549  * Description:	Go through the _posix_port_actions_t contents,
2550  *              calling task_set_special_port, task_set_exception_ports
2551  *              and/or audit_session_spawnjoin for the current task.
2552  *
2553  * Parameters:	struct image_params *	Image parameter block
2554  *
2555  * Returns:	0			Success
2556  *              EINVAL			Failure
2557  *              ENOTSUP			Illegal posix_spawn attr flag was set
2558  */
2559 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2560 exec_handle_port_actions(struct image_params *imgp,
2561     struct exec_port_actions *actions)
2562 {
2563 	_posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2564 #if CONFIG_AUDIT
2565 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2566 #endif
2567 	_ps_port_action_t *act = NULL;
2568 	task_t task = get_threadtask(imgp->ip_new_thread);
2569 	ipc_port_t port = NULL;
2570 	errno_t ret = 0;
2571 	int i = 0, portwatch_i = 0, registered_i = 0, excport_i = 0;
2572 	kern_return_t kr;
2573 	boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2574 	boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2575 	int ptrauth_task_port_count = 0;
2576 
2577 	for (i = 0; i < pacts->pspa_count; i++) {
2578 		act = &pacts->pspa_actions[i];
2579 
2580 		switch (act->port_type) {
2581 		case PSPA_SPECIAL:
2582 #if CONFIG_AUDIT
2583 		case PSPA_AU_SESSION:
2584 #endif
2585 			break;
2586 		case PSPA_EXCEPTION:
2587 			if (++actions->exception_port_count > TASK_MAX_EXCEPTION_PORT_COUNT) {
2588 				ret = EINVAL;
2589 				goto done;
2590 			}
2591 			break;
2592 		case PSPA_IMP_WATCHPORTS:
2593 			if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
2594 				ret = EINVAL;
2595 				goto done;
2596 			}
2597 			break;
2598 		case PSPA_REGISTERED_PORTS:
2599 			if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
2600 				ret = EINVAL;
2601 				goto done;
2602 			}
2603 			break;
2604 		case PSPA_PTRAUTH_TASK_PORT:
2605 			if (++ptrauth_task_port_count > 1) {
2606 				ret = EINVAL;
2607 				goto done;
2608 			}
2609 			break;
2610 		default:
2611 			ret = EINVAL;
2612 			goto done;
2613 		}
2614 	}
2615 
2616 	if (actions->exception_port_count) {
2617 		actions->excport_array = kalloc_type(struct exception_port_action_t,
2618 		    actions->exception_port_count, Z_WAITOK | Z_ZERO);
2619 
2620 		if (actions->excport_array == NULL) {
2621 			ret = ENOMEM;
2622 			goto done;
2623 		}
2624 	}
2625 	if (actions->portwatch_count) {
2626 		if (in_exec && task_has_watchport_boost) {
2627 			ret = EINVAL;
2628 			goto done;
2629 		}
2630 		actions->portwatch_array = kalloc_type(ipc_port_t,
2631 		    actions->portwatch_count, Z_WAITOK | Z_ZERO);
2632 		if (actions->portwatch_array == NULL) {
2633 			ret = ENOMEM;
2634 			goto done;
2635 		}
2636 	}
2637 
2638 	for (i = 0; i < pacts->pspa_count; i++) {
2639 		act = &pacts->pspa_actions[i];
2640 
2641 		if (MACH_PORT_VALID(act->new_port)) {
2642 			kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2643 			    act->new_port, MACH_MSG_TYPE_COPY_SEND,
2644 			    (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2645 
2646 			if (kr != KERN_SUCCESS) {
2647 				ret = EINVAL;
2648 				goto done;
2649 			}
2650 		} else {
2651 			/* it's NULL or DEAD */
2652 			port = CAST_MACH_NAME_TO_PORT(act->new_port);
2653 		}
2654 
2655 		switch (act->port_type) {
2656 		case PSPA_SPECIAL:
2657 			kr = task_set_special_port(task, act->which, port);
2658 
2659 			if (kr != KERN_SUCCESS) {
2660 				ret = EINVAL;
2661 			}
2662 			break;
2663 
2664 #if CONFIG_AUDIT
2665 		case PSPA_AU_SESSION:
2666 			ret = audit_session_spawnjoin(p, port);
2667 			if (ret) {
2668 				/* audit_session_spawnjoin() has already dropped the reference in case of error. */
2669 				goto done;
2670 			}
2671 
2672 			break;
2673 #endif
2674 		case PSPA_EXCEPTION:
2675 			assert(excport_i < actions->exception_port_count);
2676 			/* hold on to this till end of spawn */
2677 			actions->excport_array[excport_i].port_action = act;
2678 			actions->excport_array[excport_i].port = port;
2679 			excport_i++;
2680 			break;
2681 		case PSPA_IMP_WATCHPORTS:
2682 			assert(portwatch_i < actions->portwatch_count);
2683 			/* hold on to this till end of spawn */
2684 			actions->portwatch_array[portwatch_i++] = port;
2685 			break;
2686 		case PSPA_REGISTERED_PORTS:
2687 			assert(registered_i < actions->registered_count);
2688 			/* hold on to this till end of spawn */
2689 			actions->registered_array[registered_i++] = port;
2690 			break;
2691 
2692 		case PSPA_PTRAUTH_TASK_PORT:
2693 #if (DEVELOPMENT || DEBUG)
2694 #if defined(HAS_APPLE_PAC)
2695 			{
2696 				task_t ptr_auth_task = convert_port_to_task(port);
2697 
2698 				if (ptr_auth_task == TASK_NULL) {
2699 					ret = EINVAL;
2700 					break;
2701 				}
2702 
2703 				imgp->ip_inherited_shared_region_id =
2704 				    task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
2705 				    &imgp->ip_inherited_jop_pid);
2706 
2707 				/* Deallocate task ref returned by convert_port_to_task */
2708 				task_deallocate(ptr_auth_task);
2709 			}
2710 #endif /* HAS_APPLE_PAC */
2711 #endif /* (DEVELOPMENT || DEBUG) */
2712 
2713 			/* consume the port right in case of success */
2714 			ipc_port_release_send(port);
2715 			break;
2716 		default:
2717 			ret = EINVAL;
2718 			break;
2719 		}
2720 
2721 		if (ret) {
2722 			/* action failed, so release port resources */
2723 			ipc_port_release_send(port);
2724 			break;
2725 		}
2726 	}
2727 
2728 done:
2729 	if (0 != ret) {
2730 		DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2731 	}
2732 	return ret;
2733 }
2734 
2735 
2736 /*
2737  * exec_handle_exception_port_actions
2738  *
2739  * Description:	Go through the saved exception ports in exec_port_actions,
2740  *              calling task_set_exception_ports for the current Task.
2741  *              This must happen after image activation, and after exec_resettextvp()
2742  *				because task_set_exception_ports checks the `TF_PLATFORM` bit and entitlements.
2743  *
2744  * Parameters:	struct image_params *		Image parameter block
2745  *                              struct exec_port_actions *  Saved Port Actions
2746  *
2747  * Returns:	0			Success
2748  *              EINVAL			task_set_exception_ports failed
2749  */
2750 static errno_t
exec_handle_exception_port_actions(const struct image_params * imgp,const struct exec_port_actions * actions)2751 exec_handle_exception_port_actions(const struct image_params *imgp,
2752     const struct exec_port_actions *actions)
2753 {
2754 	task_t task = get_threadtask(imgp->ip_new_thread);
2755 
2756 	for (int i = 0; i < actions->exception_port_count; i++) {
2757 		ipc_port_t port = actions->excport_array[i].port;
2758 		_ps_port_action_t *act = actions->excport_array[i].port_action;
2759 		assert(act != NULL);
2760 		kern_return_t kr = task_set_exception_ports(task, act->mask, port,
2761 		    act->behavior, act->flavor);
2762 		if (kr != KERN_SUCCESS) {
2763 			DTRACE_PROC1(spawn__exception__port__failure, mach_port_name_t, act->new_port);
2764 			return EINVAL;
2765 		}
2766 		actions->excport_array[i].port = NULL;
2767 	}
2768 
2769 	return 0;
2770 }
2771 
2772 
2773 /*
2774  * exec_handle_file_actions
2775  *
2776  * Description:	Go through the _posix_file_actions_t contents applying the
2777  *		open, close, and dup2 operations to the open file table for
2778  *		the current process.
2779  *
2780  * Parameters:	struct image_params *	Image parameter block
2781  *
2782  * Returns:	0			Success
2783  *		???
2784  *
2785  * Note:	Actions are applied in the order specified, with the credential
2786  *		of the parent process.  This is done to permit the parent
2787  *		process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
2788  *		the child following operations the child may in fact not be
2789  *		normally permitted to perform.
2790  */
2791 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)2792 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
2793 {
2794 	int error = 0;
2795 	int action;
2796 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2797 	kauth_cred_t p_cred = vfs_context_ucred(imgp->ip_vfs_context);
2798 	_posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
2799 	int ival[2];            /* dummy retval for system calls) */
2800 #if CONFIG_AUDIT
2801 	struct uthread *uthread = current_uthread();
2802 #endif
2803 
2804 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
2805 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2806 
2807 		switch (psfa->psfaa_type) {
2808 		case PSFA_OPEN: {
2809 			/*
2810 			 * Open is different, in that it requires the use of
2811 			 * a path argument, which is normally copied in from
2812 			 * user space; because of this, we have to support an
2813 			 * open from kernel space that passes an address space
2814 			 * context of UIO_SYSSPACE, and casts the address
2815 			 * argument to a user_addr_t.
2816 			 */
2817 			struct vnode_attr *vap;
2818 			struct nameidata *ndp;
2819 			int mode = psfa->psfaa_openargs.psfao_mode;
2820 			int origfd;
2821 			struct {
2822 				struct vnode_attr va;
2823 				struct nameidata nd;
2824 			} *__open_data;
2825 
2826 			__open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
2827 			if (__open_data == NULL) {
2828 				error = ENOMEM;
2829 				break;
2830 			}
2831 
2832 			vap = &__open_data->va;
2833 			ndp = &__open_data->nd;
2834 
2835 			VATTR_INIT(vap);
2836 			/* Mask off all but regular access permissions */
2837 			mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
2838 			VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
2839 
2840 			AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
2841 
2842 			NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2843 			    CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
2844 			    imgp->ip_vfs_context);
2845 
2846 			error = open1(imgp->ip_vfs_context, ndp,
2847 			    psfa->psfaa_openargs.psfao_oflag,
2848 			    vap, NULL, NULL, &origfd, AUTH_OPEN_NOAUTHFD);
2849 
2850 			kfree_type(typeof(*__open_data), __open_data);
2851 
2852 			AUDIT_SUBCALL_EXIT(uthread, error);
2853 
2854 			/*
2855 			 * If there's an error, or we get the right fd by
2856 			 * accident, then drop out here.  This is easier than
2857 			 * reworking all the open code to preallocate fd
2858 			 * slots, and internally taking one as an argument.
2859 			 */
2860 			if (error || origfd == psfa->psfaa_filedes) {
2861 				break;
2862 			}
2863 
2864 			/*
2865 			 * If we didn't fall out from an error, we ended up
2866 			 * with the wrong fd; so now we've got to try to dup2
2867 			 * it to the right one.
2868 			 */
2869 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2870 			error = dup2(p, p_cred, origfd, psfa->psfaa_filedes, ival);
2871 			AUDIT_SUBCALL_EXIT(uthread, error);
2872 			if (error) {
2873 				break;
2874 			}
2875 
2876 			/*
2877 			 * Finally, close the original fd.
2878 			 */
2879 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2880 			error = close_nocancel(p, p_cred, origfd);
2881 			AUDIT_SUBCALL_EXIT(uthread, error);
2882 		}
2883 		break;
2884 
2885 		case PSFA_DUP2: {
2886 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2887 			error = dup2(p, p_cred, psfa->psfaa_filedes,
2888 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2889 			AUDIT_SUBCALL_EXIT(uthread, error);
2890 		}
2891 		break;
2892 
2893 		case PSFA_FILEPORT_DUP2: {
2894 			ipc_port_t port;
2895 			kern_return_t kr;
2896 			int origfd;
2897 
2898 			if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
2899 				error = EINVAL;
2900 				break;
2901 			}
2902 
2903 			kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2904 			    psfa->psfaa_fileport, MACH_MSG_TYPE_COPY_SEND,
2905 			    (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2906 
2907 			if (kr != KERN_SUCCESS) {
2908 				error = EINVAL;
2909 				break;
2910 			}
2911 
2912 			error = fileport_makefd(p, port, 0, &origfd);
2913 
2914 			if (IPC_PORT_NULL != port) {
2915 				ipc_port_release_send(port);
2916 			}
2917 
2918 			if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
2919 				break;
2920 			}
2921 
2922 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2923 			error = dup2(p, p_cred, origfd,
2924 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2925 			AUDIT_SUBCALL_EXIT(uthread, error);
2926 			if (error) {
2927 				break;
2928 			}
2929 
2930 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2931 			error = close_nocancel(p, p_cred, origfd);
2932 			AUDIT_SUBCALL_EXIT(uthread, error);
2933 		}
2934 		break;
2935 
2936 		case PSFA_CLOSE: {
2937 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2938 			error = close_nocancel(p, p_cred, psfa->psfaa_filedes);
2939 			AUDIT_SUBCALL_EXIT(uthread, error);
2940 		}
2941 		break;
2942 
2943 		case PSFA_INHERIT: {
2944 			struct fileproc *fp;
2945 
2946 			/*
2947 			 * Check to see if the descriptor exists, and
2948 			 * ensure it's -not- marked as close-on-exec.
2949 			 *
2950 			 * Attempting to "inherit" a guarded fd will
2951 			 * result in a error.
2952 			 */
2953 
2954 			proc_fdlock(p);
2955 			if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
2956 				error = EBADF;
2957 			} else if (fp->fp_guard_attrs) {
2958 				error = fp_guard_exception(p, psfa->psfaa_filedes,
2959 				    fp, kGUARD_EXC_NOCLOEXEC);
2960 			} else {
2961 				fp->fp_flags &= ~FP_CLOEXEC;
2962 				error = 0;
2963 			}
2964 			proc_fdunlock(p);
2965 		}
2966 		break;
2967 
2968 		case PSFA_CHDIR: {
2969 			/*
2970 			 * Chdir is different, in that it requires the use of
2971 			 * a path argument, which is normally copied in from
2972 			 * user space; because of this, we have to support a
2973 			 * chdir from kernel space that passes an address space
2974 			 * context of UIO_SYSSPACE, and casts the address
2975 			 * argument to a user_addr_t.
2976 			 */
2977 			struct nameidata *nd;
2978 			nd = kalloc_type(struct nameidata,
2979 			    Z_WAITOK | Z_ZERO | Z_NOFAIL);
2980 
2981 			AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
2982 			NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2983 			    CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
2984 			    imgp->ip_vfs_context);
2985 
2986 			error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
2987 			kfree_type(struct nameidata, nd);
2988 			AUDIT_SUBCALL_EXIT(uthread, error);
2989 		}
2990 		break;
2991 
2992 		case PSFA_FCHDIR: {
2993 			AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
2994 			error = fchdir(p, imgp->ip_vfs_context,
2995 			    psfa->psfaa_filedes, false);
2996 			AUDIT_SUBCALL_EXIT(uthread, error);
2997 		}
2998 		break;
2999 
3000 		default:
3001 			error = EINVAL;
3002 			break;
3003 		}
3004 
3005 		/* All file actions failures are considered fatal, per POSIX */
3006 
3007 		if (error) {
3008 			if (PSFA_OPEN == psfa->psfaa_type) {
3009 				DTRACE_PROC1(spawn__open__failure, uintptr_t,
3010 				    psfa->psfaa_openargs.psfao_path);
3011 			} else {
3012 				DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
3013 			}
3014 			break;
3015 		}
3016 	}
3017 
3018 	if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
3019 		return error;
3020 	}
3021 
3022 	/*
3023 	 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
3024 	 * this spawn only) as if "close on exec" is the default
3025 	 * disposition of all pre-existing file descriptors.  In this case,
3026 	 * the list of file descriptors mentioned in the file actions
3027 	 * are the only ones that can be inherited, so mark them now.
3028 	 *
3029 	 * The actual closing part comes later, in fdt_exec().
3030 	 */
3031 	proc_fdlock(p);
3032 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
3033 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3034 		int fd = psfa->psfaa_filedes;
3035 
3036 		switch (psfa->psfaa_type) {
3037 		case PSFA_DUP2:
3038 		case PSFA_FILEPORT_DUP2:
3039 			fd = psfa->psfaa_dup2args.psfad_newfiledes;
3040 			OS_FALLTHROUGH;
3041 		case PSFA_OPEN:
3042 		case PSFA_INHERIT:
3043 			*fdflags(p, fd) |= UF_INHERIT;
3044 			break;
3045 
3046 		case PSFA_CLOSE:
3047 		case PSFA_CHDIR:
3048 		case PSFA_FCHDIR:
3049 			/*
3050 			 * Although PSFA_FCHDIR does have a file descriptor, it is not
3051 			 * *creating* one, thus we do not automatically mark it for
3052 			 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
3053 			 * wishes it to be inherited should use the PSFA_INHERIT action
3054 			 * explicitly.
3055 			 */
3056 			break;
3057 		}
3058 	}
3059 	proc_fdunlock(p);
3060 
3061 	return 0;
3062 }
3063 
3064 #if CONFIG_MACF
3065 /*
3066  * Check that the extension's data is within the bounds of the
3067  * allocation storing all extensions' data
3068  */
3069 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)3070 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
3071     const _ps_mac_policy_extension_t *ext)
3072 {
3073 	uint64_t dataend;
3074 
3075 	if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
3076 		return EOVERFLOW;
3077 	}
3078 	if (__improbable(dataend > px_s->datalen)) {
3079 		return EINVAL;
3080 	}
3081 
3082 	return 0;
3083 }
3084 
3085 /*
3086  * exec_spawnattr_getmacpolicyinfo
3087  */
3088 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)3089 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
3090 {
3091 	const struct ip_px_smpx_s *px_s = macextensions;
3092 	const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
3093 	int i;
3094 
3095 	if (px_s == NULL) {
3096 		return NULL;
3097 	}
3098 
3099 	psmx = px_s->array;
3100 	if (psmx == NULL) {
3101 		return NULL;
3102 	}
3103 
3104 	for (i = 0; i < psmx->psmx_count; i++) {
3105 		const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3106 		if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
3107 			if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
3108 				panic("invalid mac policy extension data");
3109 			}
3110 			if (lenp != NULL) {
3111 				*lenp = (size_t)extension->datalen;
3112 			}
3113 			return (void *)((uintptr_t)px_s->data + extension->dataoff);
3114 		}
3115 	}
3116 
3117 	if (lenp != NULL) {
3118 		*lenp = 0;
3119 	}
3120 	return NULL;
3121 }
3122 
3123 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)3124 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
3125     struct ip_px_smpx_s *pxsp)
3126 {
3127 	_posix_spawn_mac_policy_extensions_t psmx = NULL;
3128 	uint8_t *data = NULL;
3129 	uint64_t datalen = 0;
3130 	uint64_t dataoff = 0;
3131 	int error = 0;
3132 
3133 	bzero(pxsp, sizeof(*pxsp));
3134 
3135 	if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
3136 	    px_args->mac_extensions_size > PAGE_SIZE) {
3137 		error = EINVAL;
3138 		goto bad;
3139 	}
3140 
3141 	psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
3142 	if (psmx == NULL) {
3143 		error = ENOMEM;
3144 		goto bad;
3145 	}
3146 
3147 	error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
3148 	if (error) {
3149 		goto bad;
3150 	}
3151 
3152 	size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
3153 	if (extsize == 0 || extsize > px_args->mac_extensions_size) {
3154 		error = EINVAL;
3155 		goto bad;
3156 	}
3157 
3158 	for (int i = 0; i < psmx->psmx_count; i++) {
3159 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3160 		if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
3161 			error = EINVAL;
3162 			goto bad;
3163 		}
3164 		if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
3165 			error = ENOMEM;
3166 			goto bad;
3167 		}
3168 	}
3169 
3170 	data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
3171 	if (data == NULL) {
3172 		error = ENOMEM;
3173 		goto bad;
3174 	}
3175 
3176 	for (int i = 0; i < psmx->psmx_count; i++) {
3177 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3178 
3179 #if !__LP64__
3180 		if (extension->data > UINT32_MAX) {
3181 			goto bad;
3182 		}
3183 #endif
3184 		error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
3185 		if (error) {
3186 			error = ENOMEM;
3187 			goto bad;
3188 		}
3189 		extension->dataoff = dataoff;
3190 		dataoff += extension->datalen;
3191 	}
3192 
3193 	pxsp->array = psmx;
3194 	pxsp->data = data;
3195 	pxsp->datalen = datalen;
3196 	return 0;
3197 
3198 bad:
3199 	kfree_data(psmx, px_args->mac_extensions_size);
3200 	kfree_data(data, (vm_size_t)datalen);
3201 	return error;
3202 }
3203 #endif /* CONFIG_MACF */
3204 
3205 #if CONFIG_COALITIONS
3206 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])3207 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
3208 {
3209 	for (int c = 0; c < COALITION_NUM_TYPES; c++) {
3210 		if (coal[c]) {
3211 			coalition_remove_active(coal[c]);
3212 			coalition_release(coal[c]);
3213 		}
3214 	}
3215 }
3216 #endif
3217 
3218 #if CONFIG_PERSONAS
3219 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)3220 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
3221 {
3222 	int error = 0;
3223 	struct persona *persona = NULL;
3224 	kauth_cred_t mycred = kauth_cred_get();
3225 
3226 	if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
3227 		return EPERM;
3228 	}
3229 
3230 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3231 		if (px_persona->pspi_ngroups > NGROUPS_MAX) {
3232 			return EINVAL;
3233 		}
3234 	}
3235 
3236 	persona = persona_lookup(px_persona->pspi_id);
3237 	if (!persona) {
3238 		return ESRCH;
3239 	}
3240 
3241 	// non-root process should not be allowed to set persona with uid/gid 0
3242 	if (!kauth_cred_issuser(mycred) &&
3243 	    (px_persona->pspi_uid == 0 || px_persona->pspi_gid == 0)) {
3244 		return EPERM;
3245 	}
3246 
3247 	persona_put(persona);
3248 	return error;
3249 }
3250 
3251 static bool
kauth_cred_model_setpersona(kauth_cred_t model,struct _posix_spawn_persona_info * px_persona)3252 kauth_cred_model_setpersona(
3253 	kauth_cred_t            model,
3254 	struct _posix_spawn_persona_info *px_persona)
3255 {
3256 	bool updated = false;
3257 
3258 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
3259 		updated |= kauth_cred_model_setresuid(model,
3260 		    px_persona->pspi_uid,
3261 		    px_persona->pspi_uid,
3262 		    px_persona->pspi_uid,
3263 		    KAUTH_UID_NONE);
3264 	}
3265 
3266 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
3267 		updated |= kauth_cred_model_setresgid(model,
3268 		    px_persona->pspi_gid,
3269 		    px_persona->pspi_gid,
3270 		    px_persona->pspi_gid);
3271 	}
3272 
3273 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3274 		updated |= kauth_cred_model_setgroups(model,
3275 		    px_persona->pspi_groups,
3276 		    px_persona->pspi_ngroups,
3277 		    px_persona->pspi_gmuid);
3278 	}
3279 
3280 	return updated;
3281 }
3282 
3283 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)3284 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
3285 {
3286 	struct persona *persona = NULL;
3287 
3288 	/*
3289 	 * we want to spawn into the given persona, but we want to override
3290 	 * the kauth with a different UID/GID combo
3291 	 */
3292 	persona = persona_lookup(px_persona->pspi_id);
3293 	if (!persona) {
3294 		return ESRCH;
3295 	}
3296 
3297 	return persona_proc_adopt(p, persona,
3298 	           ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
3299 		return kauth_cred_model_setpersona(model, px_persona);
3300 	});
3301 }
3302 #endif
3303 
3304 #if __arm64__
3305 #if DEVELOPMENT || DEBUG
3306 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
3307     LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
3308 
3309 __startup_func
3310 static void
legacy_footprint_entitlement_mode_init(void)3311 legacy_footprint_entitlement_mode_init(void)
3312 {
3313 	/*
3314 	 * legacy_footprint_entitlement_mode specifies the behavior we want associated
3315 	 * with the entitlement. The supported modes are:
3316 	 *
3317 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3318 	 *	Indicates that we want every process to have the memory accounting
3319 	 *	that is available in iOS 12.0 and beyond.
3320 	 *
3321 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3322 	 *	Indicates that for every process that has the 'legacy footprint entitlement',
3323 	 *      we want to give it the old iOS 11.0 accounting behavior which accounted some
3324 	 *	of the process's memory to the kernel.
3325 	 *
3326 	 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3327 	 *      Indicates that for every process that has the 'legacy footprint entitlement',
3328 	 *	we want it to have a higher memory limit which will help them acclimate to the
3329 	 *	iOS 12.0 (& beyond) accounting behavior that does the right accounting.
3330 	 *      The bonus added to the system-wide task limit to calculate this higher memory limit
3331 	 *      is available in legacy_footprint_bonus_mb.
3332 	 */
3333 
3334 	if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
3335 	    legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
3336 		legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
3337 	}
3338 }
3339 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
3340 #else
3341 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
3342 #endif
3343 
3344 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)3345 proc_legacy_footprint_entitled(proc_t p, task_t task)
3346 {
3347 #pragma unused(p)
3348 	boolean_t legacy_footprint_entitled;
3349 
3350 	switch (legacy_footprint_entitlement_mode) {
3351 	case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3352 		/* the entitlement is ignored */
3353 		break;
3354 	case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3355 		/* the entitlement grants iOS11 legacy accounting */
3356 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3357 		if (legacy_footprint_entitled) {
3358 			task_set_legacy_footprint(task);
3359 		}
3360 		break;
3361 	case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3362 		/* the entitlement grants a footprint limit increase */
3363 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3364 		if (legacy_footprint_entitled) {
3365 			task_set_extra_footprint_limit(task);
3366 		}
3367 		break;
3368 	default:
3369 		break;
3370 	}
3371 }
3372 
3373 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)3374 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
3375 {
3376 #pragma unused(p)
3377 	boolean_t ios13extended_footprint_entitled;
3378 
3379 	/* the entitlement grants a footprint limit increase */
3380 	ios13extended_footprint_entitled = memorystatus_task_has_ios13extended_footprint_limit(proc_task(p));
3381 	if (ios13extended_footprint_entitled) {
3382 		task_set_ios13extended_footprint_limit(task);
3383 	}
3384 }
3385 
3386 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)3387 proc_increased_memory_limit_entitled(proc_t p, task_t task)
3388 {
3389 	bool entitled = memorystatus_task_has_increased_memory_limit_entitlement(task);
3390 
3391 	if (entitled) {
3392 		memorystatus_act_on_entitled_task_limit(p);
3393 	}
3394 }
3395 
3396 /*
3397  * Check for any of the various entitlements that permit a higher
3398  * task footprint limit or alternate accounting and apply them.
3399  */
3400 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)3401 proc_footprint_entitlement_hacks(proc_t p, task_t task)
3402 {
3403 	proc_legacy_footprint_entitled(p, task);
3404 	proc_ios13extended_footprint_entitled(p, task);
3405 	proc_increased_memory_limit_entitled(p, task);
3406 }
3407 #endif /* __arm64__ */
3408 
3409 /*
3410  * Processes with certain entitlements are granted a jumbo-size VM map.
3411  */
3412 static inline void
proc_apply_jit_and_vm_policies(struct image_params * imgp,proc_t p,task_t task)3413 proc_apply_jit_and_vm_policies(struct image_params *imgp, proc_t p, task_t task)
3414 {
3415 #if CONFIG_MACF
3416 	bool jit_entitled = false;
3417 #endif /* CONFIG_MACF */
3418 	bool needs_jumbo_va = false;
3419 	struct _posix_spawnattr *psa = imgp->ip_px_sa;
3420 
3421 #if CONFIG_MACF
3422 	jit_entitled = (mac_proc_check_map_anon(p, proc_ucred_unsafe(p),
3423 	    0, 0, 0, MAP_JIT, NULL) == 0);
3424 	needs_jumbo_va = jit_entitled || IOTaskHasEntitlement(task,
3425 	    "com.apple.developer.kernel.extended-virtual-addressing") ||
3426 	    memorystatus_task_has_increased_memory_limit_entitlement(task);
3427 #else
3428 #pragma unused(p)
3429 #endif /* CONFIG_MACF */
3430 
3431 
3432 	if (needs_jumbo_va) {
3433 		vm_map_set_jumbo(get_task_map(task));
3434 	}
3435 
3436 	if (psa && psa->psa_max_addr) {
3437 		vm_map_set_max_addr(get_task_map(task), psa->psa_max_addr);
3438 	}
3439 
3440 #if CONFIG_MAP_RANGES
3441 	if (task_is_hardened_binary(task) && !proc_is_simulated(p)) {
3442 		/*
3443 		 * This must be done last as it needs to observe
3444 		 * any kind of VA space growth that was requested.
3445 		 * This is used by the secure allocator, so
3446 		 * must be applied to all hardened binaries
3447 		 */
3448 		vm_map_range_configure(get_task_map(task));
3449 	}
3450 #endif /* CONFIG_MAP_RANGES */
3451 
3452 #if CONFIG_MACF
3453 	if (jit_entitled) {
3454 		vm_map_set_jit_entitled(get_task_map(task));
3455 
3456 	}
3457 #endif /* CONFIG_MACF */
3458 
3459 #if XNU_TARGET_OS_OSX
3460 	/* TPRO cannot be enforced on binaries that load 3P plugins on macos - rdar://107420220 */
3461 	const bool task_loads_3P_plugins = imgp->ip_flags & IMGPF_3P_PLUGINS;
3462 #endif /* XNU_TARGET_OS_OSX */
3463 
3464 	if (task_is_hardened_binary(task)
3465 #if XNU_TARGET_OS_OSX
3466 	    && !task_loads_3P_plugins
3467 #endif /* XNU_TARGET_OS_OSX */
3468 	    ) {
3469 		/*
3470 		 * Pre-emptively disable TPRO remapping for
3471 		 * hardened binaries (which do not load 3P plugins)
3472 		 */
3473 		vm_map_set_tpro_enforcement(get_task_map(task));
3474 	}
3475 }
3476 
3477 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)3478 spawn_posix_cred_adopt(proc_t p,
3479     struct _posix_spawn_posix_cred_info *px_pcred_info)
3480 {
3481 	int error = 0;
3482 
3483 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3484 		struct setgid_args args = {
3485 			.gid = px_pcred_info->pspci_gid,
3486 		};
3487 		error = setgid(p, &args, NULL);
3488 		if (error) {
3489 			return error;
3490 		}
3491 	}
3492 
3493 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3494 		error = setgroups_internal(p,
3495 		    px_pcred_info->pspci_ngroups,
3496 		    px_pcred_info->pspci_groups,
3497 		    px_pcred_info->pspci_gmuid);
3498 		if (error) {
3499 			return error;
3500 		}
3501 	}
3502 
3503 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3504 		struct setuid_args args = {
3505 			.uid = px_pcred_info->pspci_uid,
3506 		};
3507 		error = setuid(p, &args, NULL);
3508 		if (error) {
3509 			return error;
3510 		}
3511 	}
3512 	return 0;
3513 }
3514 
3515 /*
3516  * posix_spawn
3517  *
3518  * Parameters:	uap->pid		Pointer to pid return area
3519  *		uap->fname		File name to exec
3520  *		uap->argp		Argument list
3521  *		uap->envp		Environment list
3522  *
3523  * Returns:	0			Success
3524  *		EINVAL			Invalid argument
3525  *		ENOTSUP			Not supported
3526  *		ENOEXEC			Executable file format error
3527  *	exec_activate_image:EINVAL	Invalid argument
3528  *	exec_activate_image:EACCES	Permission denied
3529  *	exec_activate_image:EINTR	Interrupted function
3530  *	exec_activate_image:ENOMEM	Not enough space
3531  *	exec_activate_image:EFAULT	Bad address
3532  *	exec_activate_image:ENAMETOOLONG	Filename too long
3533  *	exec_activate_image:ENOEXEC	Executable file format error
3534  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
3535  *	exec_activate_image:EAUTH	Image decryption failed
3536  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
3537  *	exec_activate_image:???
3538  *	mac_execve_enter:???
3539  *
3540  * TODO:	Expect to need __mac_posix_spawn() at some point...
3541  *		Handle posix_spawnattr_t
3542  *		Handle posix_spawn_file_actions_t
3543  */
3544 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3545 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3546 {
3547 	proc_t p = ap;
3548 	user_addr_t pid = uap->pid;
3549 	int ival[2];            /* dummy retval for setpgid() */
3550 	char *subsystem_root_path = NULL;
3551 	struct image_params *imgp = NULL;
3552 	struct vnode_attr *vap = NULL;
3553 	struct vnode_attr *origvap = NULL;
3554 	struct uthread  *uthread = 0;   /* compiler complains if not set to 0*/
3555 	int error, sig;
3556 	int is_64 = IS_64BIT_PROCESS(p);
3557 	struct vfs_context context;
3558 	struct user__posix_spawn_args_desc px_args = {};
3559 	struct _posix_spawnattr px_sa = {};
3560 	_posix_spawn_file_actions_t px_sfap = NULL;
3561 	_posix_spawn_port_actions_t px_spap = NULL;
3562 	struct __kern_sigaction vec;
3563 	boolean_t spawn_no_exec = FALSE;
3564 	boolean_t proc_transit_set = TRUE;
3565 	boolean_t proc_signal_set = TRUE;
3566 	boolean_t exec_done = FALSE;
3567 	os_reason_t exec_failure_reason = NULL;
3568 
3569 	struct exec_port_actions port_actions = { };
3570 	vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3571 	task_t old_task = current_task();
3572 	task_t new_task = NULL;
3573 	boolean_t should_release_proc_ref = FALSE;
3574 	void *inherit = NULL;
3575 	uint8_t crash_behavior = 0;
3576 	uint64_t crash_behavior_deadline = 0;
3577 #if CONFIG_EXCLAVES
3578 	char *task_conclave_id = NULL;
3579 #endif
3580 #if CONFIG_PERSONAS
3581 	struct _posix_spawn_persona_info *px_persona = NULL;
3582 #endif
3583 	struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3584 	struct {
3585 		struct image_params imgp;
3586 		struct vnode_attr va;
3587 		struct vnode_attr origva;
3588 	} *__spawn_data;
3589 
3590 	/*
3591 	 * Allocate a big chunk for locals instead of using stack since these
3592 	 * structures are pretty big.
3593 	 */
3594 	__spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3595 	if (__spawn_data == NULL) {
3596 		error = ENOMEM;
3597 		goto bad;
3598 	}
3599 	imgp = &__spawn_data->imgp;
3600 	vap = &__spawn_data->va;
3601 	origvap = &__spawn_data->origva;
3602 
3603 	/* Initialize the common data in the image_params structure */
3604 	imgp->ip_user_fname = uap->path;
3605 	imgp->ip_user_argv = uap->argv;
3606 	imgp->ip_user_envv = uap->envp;
3607 	imgp->ip_vattr = vap;
3608 	imgp->ip_origvattr = origvap;
3609 	imgp->ip_vfs_context = &context;
3610 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3611 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3612 	imgp->ip_mac_return = 0;
3613 	imgp->ip_px_persona = NULL;
3614 	imgp->ip_px_pcred_info = NULL;
3615 	imgp->ip_cs_error = OS_REASON_NULL;
3616 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3617 	imgp->ip_subsystem_root_path = NULL;
3618 	imgp->ip_inherited_shared_region_id = NULL;
3619 	imgp->ip_inherited_jop_pid = 0;
3620 	uthread_set_exec_data(current_uthread(), imgp);
3621 
3622 	if (uap->adesc != USER_ADDR_NULL) {
3623 		if (is_64) {
3624 			error = copyin(uap->adesc, &px_args, sizeof(px_args));
3625 		} else {
3626 			struct user32__posix_spawn_args_desc px_args32;
3627 
3628 			error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3629 
3630 			/*
3631 			 * Convert arguments descriptor from external 32 bit
3632 			 * representation to internal 64 bit representation
3633 			 */
3634 			px_args.attr_size = px_args32.attr_size;
3635 			px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3636 			px_args.file_actions_size = px_args32.file_actions_size;
3637 			px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3638 			px_args.port_actions_size = px_args32.port_actions_size;
3639 			px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3640 			px_args.mac_extensions_size = px_args32.mac_extensions_size;
3641 			px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3642 			px_args.coal_info_size = px_args32.coal_info_size;
3643 			px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3644 			px_args.persona_info_size = px_args32.persona_info_size;
3645 			px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3646 			px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3647 			px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3648 			px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3649 			px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3650 			px_args.conclave_id_size = px_args32.conclave_id_size;
3651 			px_args.conclave_id = CAST_USER_ADDR_T(px_args32.conclave_id);
3652 		}
3653 		if (error) {
3654 			goto bad;
3655 		}
3656 
3657 		if (px_args.attr_size != 0) {
3658 			/*
3659 			 * We are not copying the port_actions pointer,
3660 			 * because we already have it from px_args.
3661 			 * This is a bit fragile: <rdar://problem/16427422>
3662 			 */
3663 
3664 			if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3665 				goto bad;
3666 			}
3667 
3668 			imgp->ip_px_sa = &px_sa;
3669 		}
3670 		if (px_args.file_actions_size != 0) {
3671 			/* Limit file_actions to allowed number of open files */
3672 			size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3673 
3674 			if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3675 			    maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3676 				error = EINVAL;
3677 				goto bad;
3678 			}
3679 
3680 			px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3681 			if (px_sfap == NULL) {
3682 				error = ENOMEM;
3683 				goto bad;
3684 			}
3685 			imgp->ip_px_sfa = px_sfap;
3686 
3687 			if ((error = copyin(px_args.file_actions, px_sfap,
3688 			    px_args.file_actions_size)) != 0) {
3689 				goto bad;
3690 			}
3691 
3692 			/* Verify that the action count matches the struct size */
3693 			size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3694 			if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3695 				error = EINVAL;
3696 				goto bad;
3697 			}
3698 		}
3699 		if (px_args.port_actions_size != 0) {
3700 			/* Limit port_actions to one page of data */
3701 			if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3702 			    px_args.port_actions_size > PAGE_SIZE) {
3703 				error = EINVAL;
3704 				goto bad;
3705 			}
3706 
3707 			px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3708 			if (px_spap == NULL) {
3709 				error = ENOMEM;
3710 				goto bad;
3711 			}
3712 			imgp->ip_px_spa = px_spap;
3713 
3714 			if ((error = copyin(px_args.port_actions, px_spap,
3715 			    px_args.port_actions_size)) != 0) {
3716 				goto bad;
3717 			}
3718 
3719 			/* Verify that the action count matches the struct size */
3720 			size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3721 			if (pasize == 0 || pasize != px_args.port_actions_size) {
3722 				error = EINVAL;
3723 				goto bad;
3724 			}
3725 		}
3726 #if CONFIG_PERSONAS
3727 		/* copy in the persona info */
3728 		if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3729 			/* for now, we need the exact same struct in user space */
3730 			if (px_args.persona_info_size != sizeof(*px_persona)) {
3731 				error = ERANGE;
3732 				goto bad;
3733 			}
3734 
3735 			px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3736 			if (px_persona == NULL) {
3737 				error = ENOMEM;
3738 				goto bad;
3739 			}
3740 			imgp->ip_px_persona = px_persona;
3741 
3742 			if ((error = copyin(px_args.persona_info, px_persona,
3743 			    px_args.persona_info_size)) != 0) {
3744 				goto bad;
3745 			}
3746 			if ((error = spawn_validate_persona(px_persona)) != 0) {
3747 				goto bad;
3748 			}
3749 		}
3750 #endif
3751 		/* copy in the posix cred info */
3752 		if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
3753 			/* for now, we need the exact same struct in user space */
3754 			if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
3755 				error = ERANGE;
3756 				goto bad;
3757 			}
3758 
3759 			if (!kauth_cred_issuser(kauth_cred_get())) {
3760 				error = EPERM;
3761 				goto bad;
3762 			}
3763 
3764 			px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
3765 			if (px_pcred_info == NULL) {
3766 				error = ENOMEM;
3767 				goto bad;
3768 			}
3769 			imgp->ip_px_pcred_info = px_pcred_info;
3770 
3771 			if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
3772 			    px_args.posix_cred_info_size)) != 0) {
3773 				goto bad;
3774 			}
3775 
3776 			if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3777 				if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
3778 					error = EINVAL;
3779 					goto bad;
3780 				}
3781 			}
3782 		}
3783 #if CONFIG_MACF
3784 		if (px_args.mac_extensions_size != 0) {
3785 			if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
3786 				goto bad;
3787 			}
3788 		}
3789 #endif /* CONFIG_MACF */
3790 		if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
3791 			/*
3792 			 * If a valid-looking subsystem root has been
3793 			 * specified...
3794 			 */
3795 			if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
3796 				/*
3797 				 * ...AND the parent has the entitlement, copy
3798 				 * the subsystem root path in.
3799 				 */
3800 				subsystem_root_path = zalloc_flags(ZV_NAMEI,
3801 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3802 
3803 				if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
3804 					goto bad;
3805 				}
3806 
3807 				/* Paranoia */
3808 				subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
3809 			}
3810 		}
3811 #if CONFIG_EXCLAVES
3812 		if ((px_args.conclave_id_size > 0) && (px_args.conclave_id_size <= MAXCONCLAVENAME) &&
3813 		    (exclaves_get_status() == EXCLAVES_STATUS_AVAILABLE)) {
3814 			if (px_args.conclave_id) {
3815 				if (imgp->ip_px_sa != NULL && (px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3816 					/* Conclave id could be set only for true spawn */
3817 					error = EINVAL;
3818 					goto bad;
3819 				}
3820 				task_conclave_id = kalloc_data(MAXCONCLAVENAME,
3821 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3822 				if ((error = copyin(px_args.conclave_id, task_conclave_id, MAXCONCLAVENAME))) {
3823 					goto bad;
3824 				}
3825 				task_conclave_id[MAXCONCLAVENAME - 1] = 0;
3826 			}
3827 		}
3828 #endif
3829 	}
3830 
3831 	if (IOTaskHasEntitlement(old_task, SPAWN_SET_PANIC_CRASH_BEHAVIOR)) {
3832 		/* Truncate to uint8_t since we only support 2 flags for now */
3833 		crash_behavior = (uint8_t)px_sa.psa_crash_behavior;
3834 		crash_behavior_deadline = px_sa.psa_crash_behavior_deadline;
3835 	}
3836 
3837 	/* set uthread to parent */
3838 	uthread = current_uthread();
3839 
3840 	/*
3841 	 * <rdar://6640530>; this does not result in a behaviour change
3842 	 * relative to Leopard, so there should not be any existing code
3843 	 * which depends on it.
3844 	 */
3845 
3846 	if (imgp->ip_px_sa != NULL) {
3847 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
3848 		if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
3849 			imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
3850 		}
3851 #if (DEVELOPMENT || DEBUG)
3852 		if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
3853 			imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
3854 		}
3855 #endif
3856 
3857 		if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
3858 			goto bad;
3859 		}
3860 	}
3861 
3862 	/*
3863 	 * If we don't have the extension flag that turns "posix_spawn()"
3864 	 * into "execve() with options", then we will be creating a new
3865 	 * process which does not inherit memory from the parent process,
3866 	 * which is one of the most expensive things about using fork()
3867 	 * and execve().
3868 	 */
3869 	if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3870 		/* Set the new task's coalition, if it is requested.  */
3871 		coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
3872 #if CONFIG_COALITIONS
3873 		int i, ncoals;
3874 		kern_return_t kr = KERN_SUCCESS;
3875 		struct _posix_spawn_coalition_info coal_info;
3876 		int coal_role[COALITION_NUM_TYPES];
3877 
3878 		if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
3879 			goto do_fork1;
3880 		}
3881 
3882 		memset(&coal_info, 0, sizeof(coal_info));
3883 
3884 		if (px_args.coal_info_size > sizeof(coal_info)) {
3885 			px_args.coal_info_size = sizeof(coal_info);
3886 		}
3887 		error = copyin(px_args.coal_info,
3888 		    &coal_info, px_args.coal_info_size);
3889 		if (error != 0) {
3890 			goto bad;
3891 		}
3892 
3893 		ncoals = 0;
3894 		for (i = 0; i < COALITION_NUM_TYPES; i++) {
3895 			uint64_t cid = coal_info.psci_info[i].psci_id;
3896 			if (cid != 0) {
3897 				/*
3898 				 * don't allow tasks which are not in a
3899 				 * privileged coalition to spawn processes
3900 				 * into coalitions other than their own
3901 				 */
3902 				if (!task_is_in_privileged_coalition(proc_task(p), i) &&
3903 				    !IOTaskHasEntitlement(proc_task(p), COALITION_SPAWN_ENTITLEMENT)) {
3904 					coal_dbg("ERROR: %d not in privilegd "
3905 					    "coalition of type %d",
3906 					    proc_getpid(p), i);
3907 					spawn_coalitions_release_all(coal);
3908 					error = EPERM;
3909 					goto bad;
3910 				}
3911 
3912 				coal_dbg("searching for coalition id:%llu", cid);
3913 				/*
3914 				 * take a reference and activation on the
3915 				 * coalition to guard against free-while-spawn
3916 				 * races
3917 				 */
3918 				coal[i] = coalition_find_and_activate_by_id(cid);
3919 				if (coal[i] == COALITION_NULL) {
3920 					coal_dbg("could not find coalition id:%llu "
3921 					    "(perhaps it has been terminated or reaped)", cid);
3922 					/*
3923 					 * release any other coalition's we
3924 					 * may have a reference to
3925 					 */
3926 					spawn_coalitions_release_all(coal);
3927 					error = ESRCH;
3928 					goto bad;
3929 				}
3930 				if (coalition_type(coal[i]) != i) {
3931 					coal_dbg("coalition with id:%lld is not of type:%d"
3932 					    " (it's type:%d)", cid, i, coalition_type(coal[i]));
3933 					spawn_coalitions_release_all(coal);
3934 					error = ESRCH;
3935 					goto bad;
3936 				}
3937 				coal_role[i] = coal_info.psci_info[i].psci_role;
3938 				ncoals++;
3939 			}
3940 		}
3941 		if (ncoals < COALITION_NUM_TYPES) {
3942 			/*
3943 			 * If the user is attempting to spawn into a subset of
3944 			 * the known coalition types, then make sure they have
3945 			 * _at_least_ specified a resource coalition. If not,
3946 			 * the following fork1() call will implicitly force an
3947 			 * inheritance from 'p' and won't actually spawn the
3948 			 * new task into the coalitions the user specified.
3949 			 * (also the call to coalitions_set_roles will panic)
3950 			 */
3951 			if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
3952 				spawn_coalitions_release_all(coal);
3953 				error = EINVAL;
3954 				goto bad;
3955 			}
3956 		}
3957 do_fork1:
3958 #endif /* CONFIG_COALITIONS */
3959 
3960 		/*
3961 		 * note that this will implicitly inherit the
3962 		 * caller's persona (if it exists)
3963 		 */
3964 		error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
3965 		/* returns a thread and task reference */
3966 
3967 		if (error == 0) {
3968 			new_task = get_threadtask(imgp->ip_new_thread);
3969 		}
3970 #if CONFIG_COALITIONS
3971 		/* set the roles of this task within each given coalition */
3972 		if (error == 0) {
3973 			kr = coalitions_set_roles(coal, new_task, coal_role);
3974 			if (kr != KERN_SUCCESS) {
3975 				error = EINVAL;
3976 			}
3977 			if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
3978 			    MACH_COALITION_ADOPT))) {
3979 				for (i = 0; i < COALITION_NUM_TYPES; i++) {
3980 					if (coal[i] != COALITION_NULL) {
3981 						/*
3982 						 * On 32-bit targets, uniqueid
3983 						 * will get truncated to 32 bits
3984 						 */
3985 						KDBG_RELEASE(MACHDBG_CODE(
3986 							    DBG_MACH_COALITION,
3987 							    MACH_COALITION_ADOPT),
3988 						    coalition_id(coal[i]),
3989 						    get_task_uniqueid(new_task));
3990 					}
3991 				}
3992 			}
3993 		}
3994 
3995 		/* drop our references and activations - fork1() now holds them */
3996 		spawn_coalitions_release_all(coal);
3997 #endif /* CONFIG_COALITIONS */
3998 		if (error != 0) {
3999 			goto bad;
4000 		}
4001 		imgp->ip_flags |= IMGPF_SPAWN;  /* spawn w/o exec */
4002 		spawn_no_exec = TRUE;           /* used in later tests */
4003 	} else {
4004 		/* Adjust the user proc count */
4005 		(void)chgproccnt(kauth_getruid(), 1);
4006 		/*
4007 		 * For execve case, create a new proc, task and thread
4008 		 * but don't make the proc visible to userland. After
4009 		 * image activation, the new proc would take place of
4010 		 * the old proc in pid hash and other lists that make
4011 		 * the proc visible to the system.
4012 		 */
4013 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
4014 
4015 		/* task and thread ref returned by cloneproc */
4016 		if (imgp->ip_new_thread == NULL) {
4017 			(void)chgproccnt(kauth_getruid(), -1);
4018 			error = ENOMEM;
4019 			goto bad;
4020 		}
4021 
4022 		new_task = get_threadtask(imgp->ip_new_thread);
4023 		imgp->ip_flags |= IMGPF_EXEC;
4024 	}
4025 
4026 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
4027 
4028 	if (spawn_no_exec) {
4029 		/*
4030 		 * We had to wait until this point before firing the
4031 		 * proc:::create probe, otherwise p would not point to the
4032 		 * child process.
4033 		 */
4034 		DTRACE_PROC1(create, proc_t, p);
4035 	}
4036 	assert(p != NULL);
4037 
4038 	if (subsystem_root_path) {
4039 		/* If a subsystem root was specified, swap it in */
4040 		char * old_subsystem_root_path = p->p_subsystem_root_path;
4041 		p->p_subsystem_root_path = subsystem_root_path;
4042 		subsystem_root_path = old_subsystem_root_path;
4043 	}
4044 
4045 	p->p_crash_behavior = crash_behavior;
4046 	p->p_crash_behavior_deadline = crash_behavior_deadline;
4047 
4048 	p->p_crash_count = px_sa.psa_crash_count;
4049 	p->p_throttle_timeout = px_sa.psa_throttle_timeout;
4050 
4051 	/* We'll need the subsystem root for setting up Apple strings */
4052 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4053 
4054 	context.vc_thread = imgp->ip_new_thread;
4055 	context.vc_ucred = proc_ucred_unsafe(p);  /* in init */
4056 
4057 	/*
4058 	 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
4059 	 * to handle the file_actions.
4060 	 */
4061 
4062 	/* Has spawn file actions? */
4063 	if (imgp->ip_px_sfa != NULL) {
4064 		/*
4065 		 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
4066 		 * is handled in exec_handle_file_actions().
4067 		 */
4068 #if CONFIG_AUDIT
4069 		/*
4070 		 * The file actions auditing can overwrite the upath of
4071 		 * AUE_POSIX_SPAWN audit record.  Save the audit record.
4072 		 */
4073 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4074 		uthread->uu_ar = NULL;
4075 #endif
4076 		error = exec_handle_file_actions(imgp,
4077 		    imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
4078 #if CONFIG_AUDIT
4079 		/* Restore the AUE_POSIX_SPAWN audit record. */
4080 		uthread->uu_ar = save_uu_ar;
4081 #endif
4082 		if (error != 0) {
4083 			goto bad;
4084 		}
4085 	}
4086 
4087 	/* Has spawn port actions? */
4088 	if (imgp->ip_px_spa != NULL) {
4089 #if CONFIG_AUDIT
4090 		/*
4091 		 * Do the same for the port actions as we did for the file
4092 		 * actions.  Save the AUE_POSIX_SPAWN audit record.
4093 		 */
4094 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4095 		uthread->uu_ar = NULL;
4096 #endif
4097 		error = exec_handle_port_actions(imgp, &port_actions);
4098 #if CONFIG_AUDIT
4099 		/* Restore the AUE_POSIX_SPAWN audit record. */
4100 		uthread->uu_ar = save_uu_ar;
4101 #endif
4102 		if (error != 0) {
4103 			goto bad;
4104 		}
4105 	}
4106 
4107 	/* Has spawn attr? */
4108 	if (imgp->ip_px_sa != NULL) {
4109 		/*
4110 		 * Reset UID/GID to parent's RUID/RGID; This works only
4111 		 * because the operation occurs before the call
4112 		 * to exec_handle_sugid() by the image activator called
4113 		 * from exec_activate_image().
4114 		 *
4115 		 * POSIX requires that any setuid/setgid bits on the process
4116 		 * image will take precedence over the spawn attributes
4117 		 * (re)setting them.
4118 		 *
4119 		 * Modifications to p_ucred must be guarded using the
4120 		 * proc's ucred lock. This prevents others from accessing
4121 		 * a garbage credential.
4122 		 */
4123 		if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
4124 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
4125 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model){
4126 				return kauth_cred_model_setuidgid(model,
4127 				kauth_cred_getruid(parent),
4128 				kauth_cred_getrgid(parent));
4129 			});
4130 		}
4131 
4132 		if (imgp->ip_px_pcred_info) {
4133 			if (!spawn_no_exec) {
4134 				error = ENOTSUP;
4135 				goto bad;
4136 			}
4137 
4138 			error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
4139 			if (error != 0) {
4140 				goto bad;
4141 			}
4142 		}
4143 
4144 #if CONFIG_PERSONAS
4145 		if (imgp->ip_px_persona != NULL) {
4146 			if (!spawn_no_exec) {
4147 				error = ENOTSUP;
4148 				goto bad;
4149 			}
4150 
4151 			/*
4152 			 * If we were asked to spawn a process into a new persona,
4153 			 * do the credential switch now (which may override the UID/GID
4154 			 * inherit done just above). It's important to do this switch
4155 			 * before image activation both for reasons stated above, and
4156 			 * to ensure that the new persona has access to the image/file
4157 			 * being executed.
4158 			 */
4159 			error = spawn_persona_adopt(p, imgp->ip_px_persona);
4160 			if (error != 0) {
4161 				goto bad;
4162 			}
4163 		}
4164 #endif /* CONFIG_PERSONAS */
4165 #if !SECURE_KERNEL
4166 		/*
4167 		 * Disable ASLR for the spawned process.
4168 		 *
4169 		 * But only do so if we are not embedded + RELEASE.
4170 		 * While embedded allows for a boot-arg (-disable_aslr)
4171 		 * to deal with this (which itself is only honored on
4172 		 * DEVELOPMENT or DEBUG builds of xnu), it is often
4173 		 * useful or necessary to disable ASLR on a per-process
4174 		 * basis for unit testing and debugging.
4175 		 */
4176 		if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
4177 			OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
4178 		}
4179 #endif /* !SECURE_KERNEL */
4180 
4181 		/* Randomize high bits of ASLR slide */
4182 		if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
4183 			imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
4184 		}
4185 
4186 #if !SECURE_KERNEL
4187 		/*
4188 		 * Forcibly disallow execution from data pages for the spawned process
4189 		 * even if it would otherwise be permitted by the architecture default.
4190 		 */
4191 		if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
4192 			imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
4193 		}
4194 #endif /* !SECURE_KERNEL */
4195 
4196 #if     __has_feature(ptrauth_calls)
4197 		if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
4198 			imgp->ip_flags |= IMGPF_RESLIDE;
4199 		}
4200 #endif /* __has_feature(ptrauth_calls) */
4201 
4202 		if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
4203 		    POSIX_SPAWN_PROC_TYPE_DRIVER) {
4204 			imgp->ip_flags |= IMGPF_DRIVER;
4205 		}
4206 	}
4207 
4208 	/*
4209 	 * Disable ASLR during image activation.  This occurs either if the
4210 	 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
4211 	 * P_DISABLE_ASLR was inherited from the parent process.
4212 	 */
4213 	if (p->p_flag & P_DISABLE_ASLR) {
4214 		imgp->ip_flags |= IMGPF_DISABLE_ASLR;
4215 	}
4216 
4217 	/*
4218 	 * Clear transition flag so we won't hang if exec_activate_image() causes
4219 	 * an automount (and launchd does a proc sysctl to service it).
4220 	 *
4221 	 * <rdar://problem/6848672>, <rdar://problem/5959568>.
4222 	 */
4223 	proc_transend(p, 0);
4224 	proc_transit_set = 0;
4225 
4226 	if (!spawn_no_exec) {
4227 		/*
4228 		 * Clear the signal lock in case of exec, since
4229 		 * image activation uses psignal on child process.
4230 		 */
4231 		proc_signalend(p, 0);
4232 		proc_signal_set = 0;
4233 	}
4234 
4235 #if MAC_SPAWN   /* XXX */
4236 	if (uap->mac_p != USER_ADDR_NULL) {
4237 		error = mac_execve_enter(uap->mac_p, imgp);
4238 		if (error) {
4239 			goto bad;
4240 		}
4241 	}
4242 #endif
4243 
4244 
4245 	/*
4246 	 * Activate the image.
4247 	 * Warning: If activation failed after point of no return, it returns error
4248 	 * as 0 and pretends the call succeeded.
4249 	 */
4250 	error = exec_activate_image(imgp);
4251 #if defined(HAS_APPLE_PAC)
4252 	const uint8_t disable_user_jop = imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE;
4253 	ml_task_set_jop_pid_from_shared_region(new_task, disable_user_jop);
4254 	ml_task_set_disable_user_jop(new_task, disable_user_jop);
4255 	ml_thread_set_disable_user_jop(imgp->ip_new_thread, disable_user_jop);
4256 	ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4257 #endif
4258 
4259 
4260 	/*
4261 	 * If you've come here to add support for some new HW feature or some per-process or per-vmmap
4262 	 * or per-pmap flag that needs to be set before the process runs, or are in general lost, here
4263 	 * is some help. This summary was accurate as of Jul 2022. Use git log as needed. This comment
4264 	 * is here to prevent a recurrence of rdar://96307913
4265 	 *
4266 	 * In posix_spawn, following is what happens:
4267 	 * 1. Lots of prep and checking work
4268 	 * 2. Image activation via exec_activate_image(). The new task will get a new pmap here
4269 	 * 3. More prep work. (YOU ARE HERE)
4270 	 * 4. exec_resettextvp() is called
4271 	 * 5. At this point it is safe to check entitlements and code signatures
4272 	 * 6. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4273 	 *    The new thread is allowed to run in kernel. It cannot yet get to userland
4274 	 * 7. More things done here. This is your chance to affect the task before it runs in
4275 	 *    userspace
4276 	 * 8. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4277 	 *     The new thread is allowed to run in userland
4278 	 */
4279 
4280 	if (error == 0 && !spawn_no_exec) {
4281 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
4282 		/* proc ref returned */
4283 		should_release_proc_ref = TRUE;
4284 	}
4285 
4286 	if (error == 0) {
4287 		/* process completed the exec, but may have failed after point of no return */
4288 		exec_done = TRUE;
4289 	}
4290 
4291 #if CONFIG_EXCLAVES
4292 	if (!error && task_conclave_id != NULL) {
4293 		kern_return_t kr;
4294 		kr = task_add_conclave(new_task, imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
4295 		    task_conclave_id);
4296 		if (kr != KERN_SUCCESS) {
4297 			error = EINVAL;
4298 			goto bad;
4299 		}
4300 	}
4301 #endif
4302 
4303 	if (!error && imgp->ip_px_sa != NULL) {
4304 		thread_t child_thread = imgp->ip_new_thread;
4305 		uthread_t child_uthread = get_bsdthread_info(child_thread);
4306 
4307 		/*
4308 		 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
4309 		 * activation, else when image activation fails (before the point of no
4310 		 * return) would leave the parent process in a modified state.
4311 		 */
4312 		if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
4313 			struct setpgid_args spga;
4314 			spga.pid = proc_getpid(p);
4315 			spga.pgid = px_sa.psa_pgroup;
4316 			/*
4317 			 * Effectively, call setpgid() system call; works
4318 			 * because there are no pointer arguments.
4319 			 */
4320 			if ((error = setpgid(p, &spga, ival)) != 0) {
4321 				goto bad_px_sa;
4322 			}
4323 		}
4324 
4325 		if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
4326 			error = setsid_internal(p);
4327 			if (error != 0) {
4328 				goto bad_px_sa;
4329 			}
4330 		}
4331 
4332 		/*
4333 		 * If we have a spawn attr, and it contains signal related flags,
4334 		 * the we need to process them in the "context" of the new child
4335 		 * process, so we have to process it following image activation,
4336 		 * prior to making the thread runnable in user space.  This is
4337 		 * necessitated by some signal information being per-thread rather
4338 		 * than per-process, and we don't have the new allocation in hand
4339 		 * until after the image is activated.
4340 		 */
4341 
4342 		/*
4343 		 * Mask a list of signals, instead of them being unmasked, if
4344 		 * they were unmasked in the parent; note that some signals
4345 		 * are not maskable.
4346 		 */
4347 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
4348 			child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
4349 		}
4350 		/*
4351 		 * Default a list of signals instead of ignoring them, if
4352 		 * they were ignored in the parent.  Note that we pass
4353 		 * spawn_no_exec to setsigvec() to indicate that we called
4354 		 * fork1() and therefore do not need to call proc_signalstart()
4355 		 * internally.
4356 		 */
4357 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
4358 			vec.sa_handler = SIG_DFL;
4359 			vec.sa_tramp = 0;
4360 			vec.sa_mask = 0;
4361 			vec.sa_flags = 0;
4362 			for (sig = 1; sig < NSIG; sig++) {
4363 				if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
4364 					error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
4365 				}
4366 			}
4367 		}
4368 
4369 		/*
4370 		 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
4371 		 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
4372 		 * limit.
4373 		 *
4374 		 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
4375 		 */
4376 		if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
4377 			/*
4378 			 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
4379 			 * an entitlement to configure the monitor a certain way seems silly, since
4380 			 * whomever is turning it on could just as easily choose not to do so.
4381 			 */
4382 			error = proc_set_task_ruse_cpu(proc_task(p),
4383 			    TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
4384 			    (uint8_t)px_sa.psa_cpumonitor_percent,
4385 			    px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
4386 			    0, TRUE);
4387 		}
4388 
4389 
4390 		if (px_pcred_info &&
4391 		    (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
4392 			/*
4393 			 * setlogin() must happen after setsid()
4394 			 */
4395 			setlogin_internal(p, px_pcred_info->pspci_login);
4396 		}
4397 
4398 bad_px_sa:
4399 		if (error != 0) {
4400 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
4401 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR, 0, 0);
4402 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR);
4403 		}
4404 	}
4405 
4406 bad:
4407 
4408 	if (error == 0) {
4409 		/* reset delay idle sleep status if set */
4410 #if CONFIG_DELAY_IDLE_SLEEP
4411 		if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
4412 			OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
4413 		}
4414 #endif /* CONFIG_DELAY_IDLE_SLEEP */
4415 		/* upon  successful spawn, re/set the proc control state */
4416 		if (imgp->ip_px_sa != NULL) {
4417 			switch (px_sa.psa_pcontrol) {
4418 			case POSIX_SPAWN_PCONTROL_THROTTLE:
4419 				p->p_pcaction = P_PCTHROTTLE;
4420 				break;
4421 			case POSIX_SPAWN_PCONTROL_SUSPEND:
4422 				p->p_pcaction = P_PCSUSP;
4423 				break;
4424 			case POSIX_SPAWN_PCONTROL_KILL:
4425 				p->p_pcaction = P_PCKILL;
4426 				break;
4427 			case POSIX_SPAWN_PCONTROL_NONE:
4428 			default:
4429 				p->p_pcaction = 0;
4430 				break;
4431 			}
4432 			;
4433 		}
4434 		exec_resettextvp(p, imgp);
4435 
4436 		/*
4437 		 * Enable new task IPC access if exec_activate_image() returned an
4438 		 * active task. (Checks active bit in ipc_task_enable() under lock).
4439 		 * Must enable after resettextvp so that task port policies are not evaluated
4440 		 * until the csblob in the textvp is accurately reflected.
4441 		 */
4442 		ipc_task_enable(new_task);
4443 
4444 		/* Set task exception ports now that we can check entitlements */
4445 		if (imgp->ip_px_spa != NULL) {
4446 			error = exec_handle_exception_port_actions(imgp, &port_actions);
4447 		}
4448 
4449 #if CONFIG_MEMORYSTATUS
4450 		/* Set jetsam priority for DriverKit processes */
4451 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4452 			px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
4453 		}
4454 
4455 		/* Has jetsam attributes? */
4456 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
4457 			/*
4458 			 * With 2-level high-water-mark support, POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no
4459 			 * longer relevant, as background limits are described via the inactive limit slots.
4460 			 *
4461 			 * That said, however, if the POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in,
4462 			 * we attempt to mimic previous behavior by forcing the BG limit data into the
4463 			 * inactive/non-fatal mode and force the active slots to hold system_wide/fatal mode.
4464 			 */
4465 
4466 			if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
4467 				memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
4468 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
4469 				    TRUE,
4470 				    -1, TRUE,
4471 				    px_sa.psa_memlimit_inactive, FALSE);
4472 			} else {
4473 				memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
4474 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
4475 				    TRUE,
4476 				    px_sa.psa_memlimit_active,
4477 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL),
4478 				    px_sa.psa_memlimit_inactive,
4479 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL));
4480 			}
4481 		}
4482 
4483 		/* Has jetsam relaunch behavior? */
4484 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
4485 			/*
4486 			 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
4487 			 * This data would be used by the jetsam subsystem to determine the position and protection
4488 			 * offered to this process on dirty -> clean transitions.
4489 			 */
4490 			int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
4491 			switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
4492 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
4493 				relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
4494 				break;
4495 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
4496 				relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
4497 				break;
4498 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
4499 				relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
4500 				break;
4501 			default:
4502 				break;
4503 			}
4504 			memorystatus_relaunch_flags_update(p, relaunch_flags);
4505 		}
4506 
4507 #endif /* CONFIG_MEMORYSTATUS */
4508 		if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
4509 			task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
4510 		}
4511 
4512 #if CONFIG_PROC_RESOURCE_LIMITS
4513 		if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
4514 			task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
4515 			    (uint32_t)px_sa.psa_port_hard_limit);
4516 		}
4517 
4518 		if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
4519 			proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
4520 			    (int)px_sa.psa_filedesc_hard_limit);
4521 		}
4522 		if (imgp->ip_px_sa != NULL && (px_sa.psa_kqworkloop_soft_limit > 0 || px_sa.psa_kqworkloop_hard_limit > 0)) {
4523 			proc_set_kqworkloop_limits(p, (int)px_sa.psa_kqworkloop_soft_limit,
4524 			    (int)px_sa.psa_kqworkloop_hard_limit);
4525 		}
4526 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
4527 
4528 		/* Disable wakeup monitoring for DriverKit processes */
4529 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4530 			uint32_t      flags = WAKEMON_DISABLE;
4531 			task_wakeups_monitor_ctl(new_task, &flags, NULL);
4532 		}
4533 	}
4534 
4535 
4536 	/*
4537 	 * If we successfully called fork1() or cloneproc, we always need
4538 	 * to do this. This is because we come back from that call with
4539 	 * signals blocked in the child, and we have to unblock them, for exec
4540 	 * case they are unblocked before activation, but for true spawn case
4541 	 * we want to wait until after we've performed any spawn actions.
4542 	 * This has to happen before process_signature(), which uses psignal.
4543 	 */
4544 	if (proc_transit_set) {
4545 		proc_transend(p, 0);
4546 	}
4547 
4548 	/*
4549 	 * Drop the signal lock on the child which was taken on our
4550 	 * behalf by forkproc()/cloneproc() to prevent signals being
4551 	 * received by the child in a partially constructed state.
4552 	 */
4553 	if (proc_signal_set) {
4554 		proc_signalend(p, 0);
4555 	}
4556 
4557 	if (error == 0) {
4558 		/*
4559 		 * We need to initialize the bank context behind the protection of
4560 		 * the proc_trans lock to prevent a race with exit. We can't do this during
4561 		 * exec_activate_image because task_bank_init checks entitlements that
4562 		 * aren't loaded until subsequent calls (including exec_resettextvp).
4563 		 */
4564 		error = proc_transstart(p, 0, 0);
4565 
4566 		if (error == 0) {
4567 			task_bank_init(new_task);
4568 			proc_transend(p, 0);
4569 		}
4570 
4571 #if __arm64__
4572 		proc_footprint_entitlement_hacks(p, new_task);
4573 #endif /* __arm64__ */
4574 
4575 #if XNU_TARGET_OS_OSX
4576 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4577 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4578 			vm_map_single_jit(get_task_map(new_task));
4579 		}
4580 #endif /* XNU_TARGET_OS_OSX */
4581 
4582 #if __has_feature(ptrauth_calls)
4583 		task_set_pac_exception_fatal_flag(new_task);
4584 #endif /* __has_feature(ptrauth_calls) */
4585 		task_set_jit_exception_fatal_flag(new_task);
4586 	}
4587 
4588 	/* Inherit task role from old task to new task for exec */
4589 	if (error == 0 && !spawn_no_exec) {
4590 		proc_inherit_task_role(new_task, old_task);
4591 	}
4592 
4593 #if CONFIG_ARCADE
4594 	if (error == 0) {
4595 		/*
4596 		 * Check to see if we need to trigger an arcade upcall AST now
4597 		 * that the vnode has been reset on the task.
4598 		 */
4599 		arcade_prepare(new_task, imgp->ip_new_thread);
4600 	}
4601 #endif /* CONFIG_ARCADE */
4602 
4603 	if (error == 0) {
4604 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
4605 	}
4606 
4607 	/* Clear the initial wait on the thread before handling spawn policy */
4608 	if (imgp && imgp->ip_new_thread) {
4609 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4610 	}
4611 
4612 	/*
4613 	 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4614 	 * and bind any portwatch ports to the new task.
4615 	 * This must be done after the exec so that the child's thread is ready,
4616 	 * and after the in transit state has been released, because priority is
4617 	 * dropped here so we need to be prepared for a potentially long preemption interval
4618 	 *
4619 	 * TODO: Consider splitting this up into separate phases
4620 	 */
4621 	if (error == 0 && imgp->ip_px_sa != NULL) {
4622 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4623 
4624 		error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4625 		    psa->psa_darwin_role, &port_actions);
4626 	}
4627 
4628 	/* Transfer the turnstile watchport boost to new task if in exec */
4629 	if (error == 0 && !spawn_no_exec) {
4630 		task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4631 	}
4632 
4633 	if (error == 0 && imgp->ip_px_sa != NULL) {
4634 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4635 
4636 		if (psa->psa_no_smt) {
4637 			task_set_no_smt(new_task);
4638 		}
4639 		if (psa->psa_tecs) {
4640 			task_set_tecs(new_task);
4641 		}
4642 	}
4643 
4644 	if (error == 0 && imgp->ip_px_sa != NULL) {
4645 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4646 
4647 		if (psa->psa_options & PSA_OPTION_DATALESS_IOPOLICY) {
4648 			struct _iopol_param_t iop_param = {
4649 				.iop_scope = IOPOL_SCOPE_PROCESS,
4650 				.iop_iotype = IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES,
4651 				.iop_policy = psa->psa_dataless_iopolicy,
4652 			};
4653 			error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_SET, iop_param.iop_scope,
4654 			    iop_param.iop_policy, &iop_param);
4655 		}
4656 	}
4657 
4658 	if (error == 0) {
4659 		/* Apply the main thread qos */
4660 		thread_t main_thread = imgp->ip_new_thread;
4661 		task_set_main_thread_qos(new_task, main_thread);
4662 	}
4663 
4664 	/*
4665 	 * Release any ports we kept around for binding to the new task
4666 	 * We need to release the rights even if the posix_spawn has failed.
4667 	 */
4668 	if (imgp->ip_px_spa != NULL) {
4669 		exec_port_actions_destroy(&port_actions);
4670 	}
4671 
4672 	/*
4673 	 * We have to delay operations which might throw a signal until after
4674 	 * the signals have been unblocked; however, we want that to happen
4675 	 * after exec_resettextvp() so that the textvp is correct when they
4676 	 * fire.
4677 	 */
4678 	if (error == 0) {
4679 		error = process_signature(p, imgp);
4680 
4681 		/*
4682 		 * Pay for our earlier safety; deliver the delayed signals from
4683 		 * the incomplete spawn process now that it's complete.
4684 		 */
4685 		if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4686 			psignal_vfork(p, proc_task(p), imgp->ip_new_thread, SIGTRAP);
4687 		}
4688 
4689 		if (error == 0 && !spawn_no_exec) {
4690 			KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4691 			    proc_getpid(p));
4692 		}
4693 	}
4694 
4695 	if (spawn_no_exec) {
4696 		/* flag the 'fork' has occurred */
4697 		proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4698 	}
4699 
4700 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
4701 	if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4702 		proc_knote(p, NOTE_EXEC);
4703 	}
4704 
4705 	if (imgp != NULL) {
4706 		uthread_set_exec_data(current_uthread(), NULL);
4707 		if (imgp->ip_vp) {
4708 			vnode_put(imgp->ip_vp);
4709 		}
4710 		if (imgp->ip_scriptvp) {
4711 			vnode_put(imgp->ip_scriptvp);
4712 		}
4713 		if (imgp->ip_strings) {
4714 			execargs_free(imgp);
4715 		}
4716 		if (imgp->ip_free_map) {
4717 			/* Free the map after dropping iocount on vnode to avoid deadlock */
4718 			vm_map_deallocate(imgp->ip_free_map);
4719 		}
4720 		kfree_data(imgp->ip_px_sfa,
4721 		    px_args.file_actions_size);
4722 		kfree_data(imgp->ip_px_spa,
4723 		    px_args.port_actions_size);
4724 #if CONFIG_PERSONAS
4725 		kfree_data(imgp->ip_px_persona,
4726 		    px_args.persona_info_size);
4727 #endif
4728 		kfree_data(imgp->ip_px_pcred_info,
4729 		    px_args.posix_cred_info_size);
4730 
4731 		if (subsystem_root_path != NULL) {
4732 			zfree(ZV_NAMEI, subsystem_root_path);
4733 		}
4734 #if CONFIG_MACF
4735 		struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
4736 		kfree_data(px_s->array, px_args.mac_extensions_size);
4737 		kfree_data(px_s->data, (vm_size_t)px_s->datalen);
4738 
4739 		if (imgp->ip_execlabelp) {
4740 			mac_cred_label_free(imgp->ip_execlabelp);
4741 			imgp->ip_execlabelp = NULL;
4742 		}
4743 		if (imgp->ip_scriptlabelp) {
4744 			mac_vnode_label_free(imgp->ip_scriptlabelp);
4745 			imgp->ip_scriptlabelp = NULL;
4746 		}
4747 		if (imgp->ip_cs_error != OS_REASON_NULL) {
4748 			os_reason_free(imgp->ip_cs_error);
4749 			imgp->ip_cs_error = OS_REASON_NULL;
4750 		}
4751 		if (imgp->ip_inherited_shared_region_id != NULL) {
4752 			kfree_data(imgp->ip_inherited_shared_region_id,
4753 			    strlen(imgp->ip_inherited_shared_region_id) + 1);
4754 			imgp->ip_inherited_shared_region_id = NULL;
4755 		}
4756 #endif
4757 	}
4758 
4759 #if CONFIG_DTRACE
4760 	if (spawn_no_exec) {
4761 		/*
4762 		 * In the original DTrace reference implementation,
4763 		 * posix_spawn() was a libc routine that just
4764 		 * did vfork(2) then exec(2).  Thus the proc::: probes
4765 		 * are very fork/exec oriented.  The details of this
4766 		 * in-kernel implementation of posix_spawn() is different
4767 		 * (while producing the same process-observable effects)
4768 		 * particularly w.r.t. errors, and which thread/process
4769 		 * is constructing what on behalf of whom.
4770 		 */
4771 		if (error) {
4772 			DTRACE_PROC1(spawn__failure, int, error);
4773 		} else {
4774 			DTRACE_PROC(spawn__success);
4775 			/*
4776 			 * Some DTrace scripts, e.g. newproc.d in
4777 			 * /usr/bin, rely on the the 'exec-success'
4778 			 * probe being fired in the child after the
4779 			 * new process image has been constructed
4780 			 * in order to determine the associated pid.
4781 			 *
4782 			 * So, even though the parent built the image
4783 			 * here, for compatibility, mark the new thread
4784 			 * so 'exec-success' fires on it as it leaves
4785 			 * the kernel.
4786 			 */
4787 			dtrace_thread_didexec(imgp->ip_new_thread);
4788 		}
4789 	} else {
4790 		if (error) {
4791 			DTRACE_PROC1(exec__failure, int, error);
4792 		} else {
4793 			dtrace_thread_didexec(imgp->ip_new_thread);
4794 		}
4795 	}
4796 
4797 	if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4798 		(*dtrace_proc_waitfor_hook)(p);
4799 	}
4800 #endif
4801 
4802 #if CONFIG_AUDIT
4803 	if (!error && AUDIT_ENABLED() && p) {
4804 		/* Add the CDHash of the new process to the audit record */
4805 		uint8_t *cdhash = cs_get_cdhash(p);
4806 		if (cdhash) {
4807 			AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4808 		}
4809 	}
4810 #endif
4811 
4812 	/* terminate the new task if exec failed  */
4813 	if (new_task != NULL && task_is_exec_copy(new_task)) {
4814 		task_terminate_internal(new_task);
4815 	}
4816 
4817 	if (exec_failure_reason && !spawn_no_exec) {
4818 		psignal_with_reason(p, SIGKILL, exec_failure_reason);
4819 		exec_failure_reason = NULL;
4820 	}
4821 
4822 	/* Return to both the parent and the child? */
4823 	if (imgp != NULL && spawn_no_exec) {
4824 		/*
4825 		 * If the parent wants the pid, copy it out
4826 		 */
4827 		if (error == 0 && pid != USER_ADDR_NULL) {
4828 			_Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
4829 			bool aligned = (pid & 3) == 0;
4830 			if (aligned) {
4831 				(void)copyout_atomic32(proc_getpid(p), pid);
4832 			} else {
4833 				(void)suword(pid, proc_getpid(p));
4834 			}
4835 		}
4836 		retval[0] = error;
4837 
4838 		/*
4839 		 * If we had an error, perform an internal reap ; this is
4840 		 * entirely safe, as we have a real process backing us.
4841 		 */
4842 		if (error) {
4843 			proc_list_lock();
4844 			p->p_listflag |= P_LIST_DEADPARENT;
4845 			proc_list_unlock();
4846 			proc_lock(p);
4847 			/* make sure no one else has killed it off... */
4848 			if (p->p_stat != SZOMB && p->exit_thread == NULL) {
4849 				p->exit_thread = current_thread();
4850 				p->p_posix_spawn_failed = true;
4851 				proc_unlock(p);
4852 				exit1(p, 1, (int *)NULL);
4853 			} else {
4854 				/* someone is doing it for us; just skip it */
4855 				proc_unlock(p);
4856 			}
4857 		}
4858 	}
4859 
4860 	/*
4861 	 * Do not terminate the current task, if proc_exec_switch_task did not
4862 	 * switch the tasks, terminating the current task without the switch would
4863 	 * result in loosing the SIGKILL status.
4864 	 */
4865 	if (task_did_exec(old_task)) {
4866 		/* Terminate the current task, since exec will start in new task */
4867 		task_terminate_internal(old_task);
4868 	}
4869 
4870 	/* Release the thread ref returned by cloneproc/fork1 */
4871 	if (imgp != NULL && imgp->ip_new_thread) {
4872 		/* clear the exec complete flag if there is an error before point of no-return */
4873 		uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
4874 		if (!spawn_no_exec && !exec_done && error != 0) {
4875 			clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
4876 		}
4877 		/* wake up the new thread */
4878 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
4879 		thread_deallocate(imgp->ip_new_thread);
4880 		imgp->ip_new_thread = NULL;
4881 	}
4882 
4883 	/* Release the ref returned by cloneproc/fork1 */
4884 	if (new_task) {
4885 		task_deallocate(new_task);
4886 		new_task = NULL;
4887 	}
4888 
4889 	if (should_release_proc_ref) {
4890 		proc_rele(p);
4891 	}
4892 
4893 	kfree_type(typeof(*__spawn_data), __spawn_data);
4894 
4895 	if (inherit != NULL) {
4896 		ipc_importance_release(inherit);
4897 	}
4898 
4899 #if CONFIG_EXCLAVES
4900 	if (task_conclave_id != NULL) {
4901 		kfree_data(task_conclave_id, MAXCONCLAVENAME);
4902 	}
4903 #endif
4904 
4905 	assert(spawn_no_exec || exec_failure_reason == NULL);
4906 	return error;
4907 }
4908 
4909 /*
4910  * proc_exec_switch_task
4911  *
4912  * Parameters:  old_proc		proc before exec
4913  *		new_proc		proc after exec
4914  *		old_task		task before exec
4915  *		new_task		task after exec
4916  *		imgp			image params
4917  *		inherit			resulting importance linkage
4918  *
4919  * Returns: proc.
4920  *
4921  * Note: The function will switch proc in pid hash from old proc to new proc.
4922  * The switch needs to happen after draining all proc refs and inside
4923  * a proc list lock. In the case of failure to switch the proc, which
4924  * might happen if the process received a SIGKILL or jetsam killed it,
4925  * it will make sure that the new tasks terminates. User proc ref returned
4926  * to caller.
4927  *
4928  * This function is called after point of no return, in the case
4929  * failure to switch, it will terminate the new task and swallow the
4930  * error and let the terminated process complete exec and die.
4931  */
4932 proc_t
proc_exec_switch_task(proc_t old_proc,proc_t new_proc,task_t old_task,task_t new_task,struct image_params * imgp,void ** inherit)4933 proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task, task_t new_task, struct image_params *imgp, void **inherit)
4934 {
4935 	boolean_t task_active;
4936 	boolean_t proc_active;
4937 	boolean_t thread_active;
4938 	boolean_t reparent_traced_child = FALSE;
4939 	thread_t old_thread = current_thread();
4940 	thread_t new_thread = imgp->ip_new_thread;
4941 
4942 	thread_set_exec_promotion(old_thread);
4943 	old_proc = proc_refdrain_will_exec(old_proc);
4944 
4945 	new_proc = proc_refdrain_will_exec(new_proc);
4946 	/* extra proc ref returned to the caller */
4947 
4948 	assert(get_threadtask(new_thread) == new_task);
4949 	task_active = task_is_active(new_task);
4950 	proc_active = !(old_proc->p_lflag & P_LEXIT);
4951 
4952 	/* Check if the current thread is not aborted due to SIGKILL */
4953 	thread_active = thread_is_active(old_thread);
4954 
4955 	/*
4956 	 * Do not switch the proc if the new task or proc is already terminated
4957 	 * as a result of error in exec past point of no return
4958 	 */
4959 	if (proc_active && task_active && thread_active) {
4960 		uthread_t new_uthread = get_bsdthread_info(new_thread);
4961 		uthread_t old_uthread = current_uthread();
4962 
4963 		/* Clear dispatchqueue and workloop ast offset */
4964 		new_proc->p_dispatchqueue_offset = 0;
4965 		new_proc->p_dispatchqueue_serialno_offset = 0;
4966 		new_proc->p_dispatchqueue_label_offset = 0;
4967 		new_proc->p_return_to_kernel_offset = 0;
4968 		new_proc->p_pthread_wq_quantum_offset = 0;
4969 
4970 		/* If old_proc is session leader, change the leader to new proc */
4971 		session_replace_leader(old_proc, new_proc);
4972 
4973 		proc_lock(old_proc);
4974 
4975 		/* Copy the signal state, dtrace state and set bsd ast on new thread */
4976 		act_set_astbsd(new_thread);
4977 		new_uthread->uu_siglist |= old_uthread->uu_siglist;
4978 		new_uthread->uu_siglist |= old_proc->p_siglist;
4979 		new_uthread->uu_sigwait = old_uthread->uu_sigwait;
4980 		new_uthread->uu_sigmask = old_uthread->uu_sigmask;
4981 		new_uthread->uu_oldmask = old_uthread->uu_oldmask;
4982 		new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
4983 #if CONFIG_DTRACE
4984 		new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
4985 		new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
4986 		new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
4987 		assert(new_uthread->t_dtrace_scratch == NULL);
4988 		new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
4989 
4990 		old_uthread->t_dtrace_sig = 0;
4991 		old_uthread->t_dtrace_stop = 0;
4992 		old_uthread->t_dtrace_resumepid = 0;
4993 		old_uthread->t_dtrace_scratch = NULL;
4994 #endif
4995 
4996 #if CONFIG_PROC_UDATA_STORAGE
4997 		new_proc->p_user_data = old_proc->p_user_data;
4998 #endif /* CONFIG_PROC_UDATA_STORAGE */
4999 
5000 		/* Copy the resource accounting info */
5001 		thread_copy_resource_info(new_thread, current_thread());
5002 
5003 		/* Clear the exit reason and signal state on old thread */
5004 		old_uthread->uu_exit_reason = NULL;
5005 		old_uthread->uu_siglist = 0;
5006 
5007 		task_set_did_exec_flag(old_task);
5008 		task_clear_exec_copy_flag(new_task);
5009 
5010 		task_copy_fields_for_exec(new_task, old_task);
5011 
5012 		/*
5013 		 * Need to transfer pending watch port boosts to the new task
5014 		 * while still making sure that the old task remains in the
5015 		 * importance linkage. Create an importance linkage from old task
5016 		 * to new task, then switch the task importance base of old task
5017 		 * and new task. After the switch the port watch boost will be
5018 		 * boosting the new task and new task will be donating importance
5019 		 * to old task.
5020 		 */
5021 		*inherit = ipc_importance_exec_switch_task(old_task, new_task);
5022 
5023 		/* Transfer parent's ptrace state to child */
5024 		new_proc->p_lflag &= ~(P_LTRACED | P_LSIGEXC | P_LNOATTACH);
5025 		new_proc->p_lflag |= (old_proc->p_lflag & (P_LTRACED | P_LSIGEXC | P_LNOATTACH));
5026 		new_proc->p_oppid = old_proc->p_oppid;
5027 
5028 		if (old_proc->p_pptr != new_proc->p_pptr) {
5029 			reparent_traced_child = TRUE;
5030 			new_proc->p_lflag |= P_LTRACE_WAIT;
5031 		}
5032 
5033 		proc_unlock(old_proc);
5034 
5035 		/* Update the list of proc knotes */
5036 		proc_transfer_knotes(old_proc, new_proc);
5037 
5038 		/* Update the proc interval timers */
5039 		proc_inherit_itimers(old_proc, new_proc);
5040 
5041 		proc_list_lock();
5042 
5043 		/* Insert the new proc in child list of parent proc */
5044 		p_reparentallchildren(old_proc, new_proc);
5045 
5046 		/* Switch proc in pid hash */
5047 		phash_replace_locked(old_proc, new_proc);
5048 
5049 		/* Transfer the shadow flag to old proc */
5050 		os_atomic_andnot(&new_proc->p_refcount, P_REF_SHADOW, relaxed);
5051 		os_atomic_or(&old_proc->p_refcount, P_REF_SHADOW, relaxed);
5052 
5053 		/* Change init proc if launchd exec */
5054 		if (old_proc == initproc) {
5055 			/* Take the ref on new proc after proc_refwake_did_exec */
5056 			initproc = new_proc;
5057 			/* Drop the proc ref on old proc */
5058 			proc_rele(old_proc);
5059 		}
5060 
5061 		proc_list_unlock();
5062 #if CONFIG_EXCLAVES
5063 		if (task_inherit_conclave(old_task, new_task, imgp->ip_vp,
5064 		    (int64_t)imgp->ip_arch_offset) != KERN_SUCCESS) {
5065 			task_terminate_internal(new_task);
5066 		}
5067 #endif
5068 	} else {
5069 		task_terminate_internal(new_task);
5070 	}
5071 
5072 	proc_refwake_did_exec(new_proc);
5073 	proc_refwake_did_exec(old_proc);
5074 
5075 	/* Take a ref on initproc if it changed */
5076 	if (new_proc == initproc) {
5077 		initproc = proc_ref(new_proc, false);
5078 		assert(initproc != PROC_NULL);
5079 	}
5080 
5081 	thread_clear_exec_promotion(old_thread);
5082 	proc_rele(old_proc);
5083 
5084 	if (reparent_traced_child) {
5085 		proc_t pp = proc_parent(old_proc);
5086 		assert(pp != PROC_NULL);
5087 
5088 		proc_reparentlocked(new_proc, pp, 1, 0);
5089 		proc_rele(pp);
5090 
5091 		proc_lock(new_proc);
5092 		new_proc->p_lflag &= ~P_LTRACE_WAIT;
5093 		proc_unlock(new_proc);
5094 	}
5095 
5096 	return new_proc;
5097 }
5098 
5099 /*
5100  * execve
5101  *
5102  * Parameters:	uap->fname		File name to exec
5103  *		uap->argp		Argument list
5104  *		uap->envp		Environment list
5105  *
5106  * Returns:	0			Success
5107  *	__mac_execve:EINVAL		Invalid argument
5108  *	__mac_execve:ENOTSUP		Invalid argument
5109  *	__mac_execve:EACCES		Permission denied
5110  *	__mac_execve:EINTR		Interrupted function
5111  *	__mac_execve:ENOMEM		Not enough space
5112  *	__mac_execve:EFAULT		Bad address
5113  *	__mac_execve:ENAMETOOLONG	Filename too long
5114  *	__mac_execve:ENOEXEC		Executable file format error
5115  *	__mac_execve:ETXTBSY		Text file busy [misuse of error code]
5116  *	__mac_execve:???
5117  *
5118  * TODO:	Dynamic linker header address on stack is copied via suword()
5119  */
5120 /* ARGSUSED */
5121 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)5122 execve(proc_t p, struct execve_args *uap, int32_t *retval)
5123 {
5124 	struct __mac_execve_args muap;
5125 	int err;
5126 
5127 	memoryshot(VM_EXECVE, DBG_FUNC_NONE);
5128 
5129 	muap.fname = uap->fname;
5130 	muap.argp = uap->argp;
5131 	muap.envp = uap->envp;
5132 	muap.mac_p = USER_ADDR_NULL;
5133 	err = __mac_execve(p, &muap, retval);
5134 
5135 	return err;
5136 }
5137 
5138 /*
5139  * __mac_execve
5140  *
5141  * Parameters:	uap->fname		File name to exec
5142  *		uap->argp		Argument list
5143  *		uap->envp		Environment list
5144  *		uap->mac_p		MAC label supplied by caller
5145  *
5146  * Returns:	0			Success
5147  *		EINVAL			Invalid argument
5148  *		ENOTSUP			Not supported
5149  *		ENOEXEC			Executable file format error
5150  *	exec_activate_image:EINVAL	Invalid argument
5151  *	exec_activate_image:EACCES	Permission denied
5152  *	exec_activate_image:EINTR	Interrupted function
5153  *	exec_activate_image:ENOMEM	Not enough space
5154  *	exec_activate_image:EFAULT	Bad address
5155  *	exec_activate_image:ENAMETOOLONG	Filename too long
5156  *	exec_activate_image:ENOEXEC	Executable file format error
5157  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
5158  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
5159  *	exec_activate_image:???
5160  *	mac_execve_enter:???
5161  *
5162  * TODO:	Dynamic linker header address on stack is copied via suword()
5163  */
5164 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)5165 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
5166 {
5167 	struct image_params *imgp = NULL;
5168 	struct vnode_attr *vap = NULL;
5169 	struct vnode_attr *origvap = NULL;
5170 	int error;
5171 	int is_64 = IS_64BIT_PROCESS(p);
5172 	struct vfs_context context;
5173 	struct uthread  *uthread = NULL;
5174 	task_t old_task = current_task();
5175 	task_t new_task = NULL;
5176 	boolean_t should_release_proc_ref = FALSE;
5177 	boolean_t exec_done = FALSE;
5178 	void *inherit = NULL;
5179 	struct {
5180 		struct image_params imgp;
5181 		struct vnode_attr va;
5182 		struct vnode_attr origva;
5183 	} *__execve_data;
5184 
5185 	/* Allocate a big chunk for locals instead of using stack since these
5186 	 * structures a pretty big.
5187 	 */
5188 	__execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
5189 	if (__execve_data == NULL) {
5190 		error = ENOMEM;
5191 		goto exit_with_error;
5192 	}
5193 	imgp = &__execve_data->imgp;
5194 	vap = &__execve_data->va;
5195 	origvap = &__execve_data->origva;
5196 
5197 	/* Initialize the common data in the image_params structure */
5198 	imgp->ip_user_fname = uap->fname;
5199 	imgp->ip_user_argv = uap->argp;
5200 	imgp->ip_user_envv = uap->envp;
5201 	imgp->ip_vattr = vap;
5202 	imgp->ip_origvattr = origvap;
5203 	imgp->ip_vfs_context = &context;
5204 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
5205 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
5206 	imgp->ip_mac_return = 0;
5207 	imgp->ip_cs_error = OS_REASON_NULL;
5208 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
5209 	imgp->ip_subsystem_root_path = NULL;
5210 	uthread_set_exec_data(current_uthread(), imgp);
5211 
5212 #if CONFIG_MACF
5213 	if (uap->mac_p != USER_ADDR_NULL) {
5214 		error = mac_execve_enter(uap->mac_p, imgp);
5215 		if (error) {
5216 			goto exit_with_error;
5217 		}
5218 	}
5219 #endif
5220 	uthread = current_uthread();
5221 	{
5222 		imgp->ip_flags |= IMGPF_EXEC;
5223 
5224 		/* Adjust the user proc count */
5225 		(void)chgproccnt(kauth_getruid(), 1);
5226 		/*
5227 		 * For execve case, create a new proc, task and thread
5228 		 * but don't make the proc visible to userland. After
5229 		 * image activation, the new proc would take place of
5230 		 * the old proc in pid hash and other lists that make
5231 		 * the proc visible to the system.
5232 		 */
5233 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
5234 		/* task and thread ref returned by cloneproc */
5235 		if (imgp->ip_new_thread == NULL) {
5236 			(void)chgproccnt(kauth_getruid(), -1);
5237 			error = ENOMEM;
5238 			goto exit_with_error;
5239 		}
5240 
5241 		new_task = get_threadtask(imgp->ip_new_thread);
5242 	}
5243 
5244 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
5245 
5246 	context.vc_thread = imgp->ip_new_thread;
5247 	context.vc_ucred = kauth_cred_proc_ref(p);      /* XXX must NOT be kauth_cred_get() */
5248 
5249 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
5250 
5251 	proc_transend(p, 0);
5252 	proc_signalend(p, 0);
5253 
5254 
5255 	/*
5256 	 * Activate the image.
5257 	 * Warning: If activation failed after point of no return, it returns error
5258 	 * as 0 and pretends the call succeeded.
5259 	 */
5260 	error = exec_activate_image(imgp);
5261 	/* thread and task ref returned for vfexec case */
5262 
5263 	if (imgp->ip_new_thread != NULL) {
5264 		/*
5265 		 * task reference might be returned by exec_activate_image
5266 		 * for vfexec.
5267 		 */
5268 		new_task = get_threadtask(imgp->ip_new_thread);
5269 #if defined(HAS_APPLE_PAC)
5270 		ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5271 		ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5272 #endif
5273 	}
5274 
5275 	if (!error) {
5276 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
5277 		/* proc ref returned */
5278 		should_release_proc_ref = TRUE;
5279 	}
5280 
5281 	kauth_cred_unref(&context.vc_ucred);
5282 
5283 	if (!error) {
5284 		exec_done = TRUE;
5285 		assert(imgp->ip_new_thread != NULL);
5286 
5287 		exec_resettextvp(p, imgp);
5288 		/*
5289 		 * Enable new task IPC access if exec_activate_image() returned an
5290 		 * active task. (Checks active bit in ipc_task_enable() under lock).
5291 		 * Must enable after resettextvp so that task port policies are not evaluated
5292 		 * until the csblob in the textvp is accurately reflected.
5293 		 */
5294 		ipc_task_enable(new_task);
5295 		error = process_signature(p, imgp);
5296 	}
5297 
5298 #if defined(HAS_APPLE_PAC)
5299 	if (imgp->ip_new_thread && !error) {
5300 		ml_task_set_jop_pid_from_shared_region(new_task, imgp->ip_flags & IMGPF_NOJOP);
5301 		ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
5302 	}
5303 #endif /* defined(HAS_APPLE_PAC) */
5304 
5305 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
5306 	if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
5307 		proc_knote(p, NOTE_EXEC);
5308 	}
5309 
5310 	if (imgp->ip_vp != NULLVP) {
5311 		vnode_put(imgp->ip_vp);
5312 	}
5313 	if (imgp->ip_scriptvp != NULLVP) {
5314 		vnode_put(imgp->ip_scriptvp);
5315 	}
5316 	if (imgp->ip_free_map) {
5317 		/* Free the map after dropping iocount on vnode to avoid deadlock */
5318 		vm_map_deallocate(imgp->ip_free_map);
5319 	}
5320 	if (imgp->ip_strings) {
5321 		execargs_free(imgp);
5322 	}
5323 #if CONFIG_MACF
5324 	if (imgp->ip_execlabelp) {
5325 		mac_cred_label_free(imgp->ip_execlabelp);
5326 		imgp->ip_execlabelp = NULL;
5327 	}
5328 	if (imgp->ip_scriptlabelp) {
5329 		mac_vnode_label_free(imgp->ip_scriptlabelp);
5330 		imgp->ip_scriptlabelp = NULL;
5331 	}
5332 #endif
5333 	if (imgp->ip_cs_error != OS_REASON_NULL) {
5334 		os_reason_free(imgp->ip_cs_error);
5335 		imgp->ip_cs_error = OS_REASON_NULL;
5336 	}
5337 
5338 	if (!error) {
5339 		/*
5340 		 * We need to initialize the bank context behind the protection of
5341 		 * the proc_trans lock to prevent a race with exit. We can't do this during
5342 		 * exec_activate_image because task_bank_init checks entitlements that
5343 		 * aren't loaded until subsequent calls (including exec_resettextvp).
5344 		 */
5345 		error = proc_transstart(p, 0, 0);
5346 	}
5347 
5348 	if (!error) {
5349 		task_bank_init(new_task);
5350 		proc_transend(p, 0);
5351 
5352 		// Don't inherit crash behavior across exec
5353 		p->p_crash_behavior = 0;
5354 		p->p_crash_behavior_deadline = 0;
5355 
5356 #if __arm64__
5357 		proc_footprint_entitlement_hacks(p, new_task);
5358 #endif /* __arm64__ */
5359 
5360 #if XNU_TARGET_OS_OSX
5361 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
5362 			vm_map_single_jit(get_task_map(new_task));
5363 		}
5364 #endif /* XNU_TARGET_OS_OSX */
5365 
5366 		/* Sever any extant thread affinity */
5367 		thread_affinity_exec(current_thread());
5368 
5369 		/* Inherit task role from old task to new task for exec */
5370 		proc_inherit_task_role(new_task, old_task);
5371 
5372 		thread_t main_thread = imgp->ip_new_thread;
5373 
5374 		task_set_main_thread_qos(new_task, main_thread);
5375 
5376 #if __has_feature(ptrauth_calls)
5377 		task_set_pac_exception_fatal_flag(new_task);
5378 #endif /* __has_feature(ptrauth_calls) */
5379 		task_set_jit_exception_fatal_flag(new_task);
5380 
5381 #if CONFIG_ARCADE
5382 		/*
5383 		 * Check to see if we need to trigger an arcade upcall AST now
5384 		 * that the vnode has been reset on the task.
5385 		 */
5386 		arcade_prepare(new_task, imgp->ip_new_thread);
5387 #endif /* CONFIG_ARCADE */
5388 
5389 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
5390 
5391 		if (vm_darkwake_mode == TRUE) {
5392 			/*
5393 			 * This process is being launched when the system
5394 			 * is in darkwake. So mark it specially. This will
5395 			 * cause all its pages to be entered in the background Q.
5396 			 */
5397 			task_set_darkwake_mode(new_task, vm_darkwake_mode);
5398 		}
5399 
5400 #if CONFIG_DTRACE
5401 		dtrace_thread_didexec(imgp->ip_new_thread);
5402 
5403 		if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5404 			(*dtrace_proc_waitfor_hook)(p);
5405 		}
5406 #endif
5407 
5408 #if CONFIG_AUDIT
5409 		if (!error && AUDIT_ENABLED() && p) {
5410 			/* Add the CDHash of the new process to the audit record */
5411 			uint8_t *cdhash = cs_get_cdhash(p);
5412 			if (cdhash) {
5413 				AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5414 			}
5415 		}
5416 #endif
5417 	} else {
5418 		DTRACE_PROC1(exec__failure, int, error);
5419 	}
5420 
5421 exit_with_error:
5422 
5423 	/* terminate the new task it if exec failed  */
5424 	if (new_task != NULL && task_is_exec_copy(new_task)) {
5425 		task_terminate_internal(new_task);
5426 	}
5427 
5428 	if (imgp != NULL) {
5429 		/* Clear the initial wait on the thread transferring watchports */
5430 		if (imgp->ip_new_thread) {
5431 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
5432 		}
5433 
5434 		/* Transfer the watchport boost to new task */
5435 		if (!error) {
5436 			task_transfer_turnstile_watchports(old_task,
5437 			    new_task, imgp->ip_new_thread);
5438 		}
5439 		/*
5440 		 * Do not terminate the current task, if proc_exec_switch_task did not
5441 		 * switch the tasks, terminating the current task without the switch would
5442 		 * result in loosing the SIGKILL status.
5443 		 */
5444 		if (task_did_exec(old_task)) {
5445 			/* Terminate the current task, since exec will start in new task */
5446 			task_terminate_internal(old_task);
5447 		}
5448 
5449 		/* Release the thread ref returned by cloneproc */
5450 		if (imgp->ip_new_thread) {
5451 			/* clear the exec complete flag if there is an error before point of no-return */
5452 			uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5453 			if (!exec_done && error != 0) {
5454 				clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5455 			}
5456 			/* wake up the new exec thread */
5457 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5458 			thread_deallocate(imgp->ip_new_thread);
5459 			imgp->ip_new_thread = NULL;
5460 		}
5461 	}
5462 
5463 	/* Release the ref returned by fork_create_child */
5464 	if (new_task) {
5465 		task_deallocate(new_task);
5466 		new_task = NULL;
5467 	}
5468 
5469 	if (should_release_proc_ref) {
5470 		proc_rele(p);
5471 	}
5472 
5473 	uthread_set_exec_data(current_uthread(), NULL);
5474 	kfree_type(typeof(*__execve_data), __execve_data);
5475 
5476 	if (inherit != NULL) {
5477 		ipc_importance_release(inherit);
5478 	}
5479 
5480 	return error;
5481 }
5482 
5483 
5484 /*
5485  * copyinptr
5486  *
5487  * Description:	Copy a pointer in from user space to a user_addr_t in kernel
5488  *		space, based on 32/64 bitness of the user space
5489  *
5490  * Parameters:	froma			User space address
5491  *		toptr			Address of kernel space user_addr_t
5492  *		ptr_size		4/8, based on 'froma' address space
5493  *
5494  * Returns:	0			Success
5495  *		EFAULT			Bad 'froma'
5496  *
5497  * Implicit returns:
5498  *		*ptr_size		Modified
5499  */
5500 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)5501 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
5502 {
5503 	int error;
5504 
5505 	if (ptr_size == 4) {
5506 		/* 64 bit value containing 32 bit address */
5507 		unsigned int i = 0;
5508 
5509 		error = copyin(froma, &i, 4);
5510 		*toptr = CAST_USER_ADDR_T(i);   /* SAFE */
5511 	} else {
5512 		error = copyin(froma, toptr, 8);
5513 	}
5514 	return error;
5515 }
5516 
5517 
5518 /*
5519  * copyoutptr
5520  *
5521  * Description:	Copy a pointer out from a user_addr_t in kernel space to
5522  *		user space, based on 32/64 bitness of the user space
5523  *
5524  * Parameters:	ua			User space address to copy to
5525  *		ptr			Address of kernel space user_addr_t
5526  *		ptr_size		4/8, based on 'ua' address space
5527  *
5528  * Returns:	0			Success
5529  *		EFAULT			Bad 'ua'
5530  *
5531  */
5532 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)5533 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
5534 {
5535 	int error;
5536 
5537 	if (ptr_size == 4) {
5538 		/* 64 bit value containing 32 bit address */
5539 		unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua);   /* SAFE */
5540 
5541 		error = copyout(&i, ptr, 4);
5542 	} else {
5543 		error = copyout(&ua, ptr, 8);
5544 	}
5545 	return error;
5546 }
5547 
5548 
5549 /*
5550  * exec_copyout_strings
5551  *
5552  * Copy out the strings segment to user space.  The strings segment is put
5553  * on a preinitialized stack frame.
5554  *
5555  * Parameters:	struct image_params *	the image parameter block
5556  *		int *			a pointer to the stack offset variable
5557  *
5558  * Returns:	0			Success
5559  *		!0			Faiure: errno
5560  *
5561  * Implicit returns:
5562  *		(*stackp)		The stack offset, modified
5563  *
5564  * Note:	The strings segment layout is backward, from the beginning
5565  *		of the top of the stack to consume the minimal amount of
5566  *		space possible; the returned stack pointer points to the
5567  *		end of the area consumed (stacks grow downward).
5568  *
5569  *		argc is an int; arg[i] are pointers; env[i] are pointers;
5570  *		the 0's are (void *)NULL's
5571  *
5572  * The stack frame layout is:
5573  *
5574  *      +-------------+ <- p->user_stack
5575  *      |     16b     |
5576  *      +-------------+
5577  *      | STRING AREA |
5578  *      |      :      |
5579  *      |      :      |
5580  *      |      :      |
5581  *      +- -- -- -- --+
5582  *      |  PATH AREA  |
5583  *      +-------------+
5584  *      |      0      |
5585  *      +-------------+
5586  *      |  applev[n]  |
5587  *      +-------------+
5588  *             :
5589  *             :
5590  *      +-------------+
5591  *      |  applev[1]  |
5592  *      +-------------+
5593  *      | exec_path / |
5594  *      |  applev[0]  |
5595  *      +-------------+
5596  *      |      0      |
5597  *      +-------------+
5598  *      |    env[n]   |
5599  *      +-------------+
5600  *             :
5601  *             :
5602  *      +-------------+
5603  *      |    env[0]   |
5604  *      +-------------+
5605  *      |      0      |
5606  *      +-------------+
5607  *      | arg[argc-1] |
5608  *      +-------------+
5609  *             :
5610  *             :
5611  *      +-------------+
5612  *      |    arg[0]   |
5613  *      +-------------+
5614  *      |     argc    |
5615  * sp-> +-------------+
5616  *
5617  * Although technically a part of the STRING AREA, we treat the PATH AREA as
5618  * a separate entity.  This allows us to align the beginning of the PATH AREA
5619  * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
5620  * which preceed it on the stack are properly aligned.
5621  */
5622 __attribute__((noinline))
5623 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)5624 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
5625 {
5626 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5627 	int     ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5628 	int     ptr_area_size;
5629 	void *ptr_buffer_start, *ptr_buffer;
5630 	size_t string_size;
5631 
5632 	user_addr_t     string_area;    /* *argv[], *env[] */
5633 	user_addr_t     ptr_area;       /* argv[], env[], applev[] */
5634 	user_addr_t argc_area;  /* argc */
5635 	user_addr_t     stack;
5636 	int error;
5637 
5638 	unsigned i;
5639 	struct copyout_desc {
5640 		char    *start_string;
5641 		int             count;
5642 #if CONFIG_DTRACE
5643 		user_addr_t     *dtrace_cookie;
5644 #endif
5645 		boolean_t       null_term;
5646 	} descriptors[] = {
5647 		{
5648 			.start_string = imgp->ip_startargv,
5649 			.count = imgp->ip_argc,
5650 #if CONFIG_DTRACE
5651 			.dtrace_cookie = &p->p_dtrace_argv,
5652 #endif
5653 			.null_term = TRUE
5654 		},
5655 		{
5656 			.start_string = imgp->ip_endargv,
5657 			.count = imgp->ip_envc,
5658 #if CONFIG_DTRACE
5659 			.dtrace_cookie = &p->p_dtrace_envp,
5660 #endif
5661 			.null_term = TRUE
5662 		},
5663 		{
5664 			.start_string = imgp->ip_strings,
5665 			.count = 1,
5666 #if CONFIG_DTRACE
5667 			.dtrace_cookie = NULL,
5668 #endif
5669 			.null_term = FALSE
5670 		},
5671 		{
5672 			.start_string = imgp->ip_endenvv,
5673 			.count = imgp->ip_applec - 1, /* exec_path handled above */
5674 #if CONFIG_DTRACE
5675 			.dtrace_cookie = NULL,
5676 #endif
5677 			.null_term = TRUE
5678 		}
5679 	};
5680 
5681 	stack = *stackp;
5682 
5683 	/*
5684 	 * All previous contributors to the string area
5685 	 * should have aligned their sub-area
5686 	 */
5687 	if (imgp->ip_strspace % ptr_size != 0) {
5688 		error = EINVAL;
5689 		goto bad;
5690 	}
5691 
5692 	/* Grow the stack down for the strings we've been building up */
5693 	string_size = imgp->ip_strendp - imgp->ip_strings;
5694 	stack -= string_size;
5695 	string_area = stack;
5696 
5697 	/*
5698 	 * Need room for one pointer for each string, plus
5699 	 * one for the NULLs terminating the argv, envv, and apple areas.
5700 	 */
5701 	ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5702 	stack -= ptr_area_size;
5703 	ptr_area = stack;
5704 
5705 	/* We'll construct all the pointer arrays in our string buffer,
5706 	 * which we already know is aligned properly, and ip_argspace
5707 	 * was used to verify we have enough space.
5708 	 */
5709 	ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5710 
5711 	/*
5712 	 * Need room for pointer-aligned argc slot.
5713 	 */
5714 	stack -= ptr_size;
5715 	argc_area = stack;
5716 
5717 	/*
5718 	 * Record the size of the arguments area so that sysctl_procargs()
5719 	 * can return the argument area without having to parse the arguments.
5720 	 */
5721 	proc_lock(p);
5722 	p->p_argc = imgp->ip_argc;
5723 	p->p_argslen = (int)(*stackp - string_area);
5724 	proc_unlock(p);
5725 
5726 	/* Return the initial stack address: the location of argc */
5727 	*stackp = stack;
5728 
5729 	/*
5730 	 * Copy out the entire strings area.
5731 	 */
5732 	error = copyout(imgp->ip_strings, string_area,
5733 	    string_size);
5734 	if (error) {
5735 		goto bad;
5736 	}
5737 
5738 	for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
5739 		char *cur_string = descriptors[i].start_string;
5740 		int j;
5741 
5742 #if CONFIG_DTRACE
5743 		if (descriptors[i].dtrace_cookie) {
5744 			proc_lock(p);
5745 			*descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
5746 			proc_unlock(p);
5747 		}
5748 #endif /* CONFIG_DTRACE */
5749 
5750 		/*
5751 		 * For each segment (argv, envv, applev), copy as many pointers as requested
5752 		 * to our pointer buffer.
5753 		 */
5754 		for (j = 0; j < descriptors[i].count; j++) {
5755 			user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
5756 
5757 			/* Copy out the pointer to the current string. Alignment has been verified  */
5758 			if (ptr_size == 8) {
5759 				*(uint64_t *)ptr_buffer = (uint64_t)cur_address;
5760 			} else {
5761 				*(uint32_t *)ptr_buffer = (uint32_t)cur_address;
5762 			}
5763 
5764 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5765 			cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
5766 		}
5767 
5768 		if (descriptors[i].null_term) {
5769 			if (ptr_size == 8) {
5770 				*(uint64_t *)ptr_buffer = 0ULL;
5771 			} else {
5772 				*(uint32_t *)ptr_buffer = 0;
5773 			}
5774 
5775 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5776 		}
5777 	}
5778 
5779 	/*
5780 	 * Copy out all our pointer arrays in bulk.
5781 	 */
5782 	error = copyout(ptr_buffer_start, ptr_area,
5783 	    ptr_area_size);
5784 	if (error) {
5785 		goto bad;
5786 	}
5787 
5788 	/* argc (int32, stored in a ptr_size area) */
5789 	error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
5790 	if (error) {
5791 		goto bad;
5792 	}
5793 
5794 bad:
5795 	return error;
5796 }
5797 
5798 
5799 /*
5800  * exec_extract_strings
5801  *
5802  * Copy arguments and environment from user space into work area; we may
5803  * have already copied some early arguments into the work area, and if
5804  * so, any arguments opied in are appended to those already there.
5805  * This function is the primary manipulator of ip_argspace, since
5806  * these are the arguments the client of execve(2) knows about. After
5807  * each argv[]/envv[] string is copied, we charge the string length
5808  * and argv[]/envv[] pointer slot to ip_argspace, so that we can
5809  * full preflight the arg list size.
5810  *
5811  * Parameters:	struct image_params *	the image parameter block
5812  *
5813  * Returns:	0			Success
5814  *		!0			Failure: errno
5815  *
5816  * Implicit returns;
5817  *		(imgp->ip_argc)		Count of arguments, updated
5818  *		(imgp->ip_envc)		Count of environment strings, updated
5819  *		(imgp->ip_argspace)	Count of remaining of NCARGS
5820  *		(imgp->ip_interp_buffer)	Interpreter and args (mutated in place)
5821  *
5822  *
5823  * Note:	The argument and environment vectors are user space pointers
5824  *		to arrays of user space pointers.
5825  */
5826 __attribute__((noinline))
5827 static int
exec_extract_strings(struct image_params * imgp)5828 exec_extract_strings(struct image_params *imgp)
5829 {
5830 	int error = 0;
5831 	int     ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
5832 	int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5833 	user_addr_t     argv = imgp->ip_user_argv;
5834 	user_addr_t     envv = imgp->ip_user_envv;
5835 
5836 	/*
5837 	 * Adjust space reserved for the path name by however much padding it
5838 	 * needs. Doing this here since we didn't know if this would be a 32-
5839 	 * or 64-bit process back in exec_save_path.
5840 	 */
5841 	while (imgp->ip_strspace % new_ptr_size != 0) {
5842 		*imgp->ip_strendp++ = '\0';
5843 		imgp->ip_strspace--;
5844 		/* imgp->ip_argspace--; not counted towards exec args total */
5845 	}
5846 
5847 	/*
5848 	 * From now on, we start attributing string space to ip_argspace
5849 	 */
5850 	imgp->ip_startargv = imgp->ip_strendp;
5851 	imgp->ip_argc = 0;
5852 
5853 	if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
5854 		user_addr_t     arg;
5855 		char *argstart, *ch;
5856 
5857 		/* First, the arguments in the "#!" string are tokenized and extracted. */
5858 		argstart = imgp->ip_interp_buffer;
5859 		while (argstart) {
5860 			ch = argstart;
5861 			while (*ch && !IS_WHITESPACE(*ch)) {
5862 				ch++;
5863 			}
5864 
5865 			if (*ch == '\0') {
5866 				/* last argument, no need to NUL-terminate */
5867 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5868 				argstart = NULL;
5869 			} else {
5870 				/* NUL-terminate */
5871 				*ch = '\0';
5872 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5873 
5874 				/*
5875 				 * Find the next string. We know spaces at the end of the string have already
5876 				 * been stripped.
5877 				 */
5878 				argstart = ch + 1;
5879 				while (IS_WHITESPACE(*argstart)) {
5880 					argstart++;
5881 				}
5882 			}
5883 
5884 			/* Error-check, regardless of whether this is the last interpreter arg or not */
5885 			if (error) {
5886 				goto bad;
5887 			}
5888 			if (imgp->ip_argspace < new_ptr_size) {
5889 				error = E2BIG;
5890 				goto bad;
5891 			}
5892 			imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5893 			imgp->ip_argc++;
5894 		}
5895 
5896 		if (argv != 0LL) {
5897 			/*
5898 			 * If we are running an interpreter, replace the av[0] that was
5899 			 * passed to execve() with the path name that was
5900 			 * passed to execve() for interpreters which do not use the PATH
5901 			 * to locate their script arguments.
5902 			 */
5903 			error = copyinptr(argv, &arg, ptr_size);
5904 			if (error) {
5905 				goto bad;
5906 			}
5907 			if (arg != 0LL) {
5908 				argv += ptr_size; /* consume without using */
5909 			}
5910 		}
5911 
5912 		if (imgp->ip_interp_sugid_fd != -1) {
5913 			char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
5914 			snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
5915 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
5916 		} else {
5917 			error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
5918 		}
5919 
5920 		if (error) {
5921 			goto bad;
5922 		}
5923 		if (imgp->ip_argspace < new_ptr_size) {
5924 			error = E2BIG;
5925 			goto bad;
5926 		}
5927 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5928 		imgp->ip_argc++;
5929 	}
5930 
5931 	while (argv != 0LL) {
5932 		user_addr_t     arg;
5933 
5934 		error = copyinptr(argv, &arg, ptr_size);
5935 		if (error) {
5936 			goto bad;
5937 		}
5938 
5939 		if (arg == 0LL) {
5940 			break;
5941 		}
5942 
5943 		argv += ptr_size;
5944 
5945 		/*
5946 		 * av[n...] = arg[n]
5947 		 */
5948 		error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
5949 		if (error) {
5950 			goto bad;
5951 		}
5952 		if (imgp->ip_argspace < new_ptr_size) {
5953 			error = E2BIG;
5954 			goto bad;
5955 		}
5956 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5957 		imgp->ip_argc++;
5958 	}
5959 
5960 	/* Save space for argv[] NULL terminator */
5961 	if (imgp->ip_argspace < new_ptr_size) {
5962 		error = E2BIG;
5963 		goto bad;
5964 	}
5965 	imgp->ip_argspace -= new_ptr_size;
5966 
5967 	/* Note where the args ends and env begins. */
5968 	imgp->ip_endargv = imgp->ip_strendp;
5969 	imgp->ip_envc = 0;
5970 
5971 	/* Now, get the environment */
5972 	while (envv != 0LL) {
5973 		user_addr_t     env;
5974 
5975 		error = copyinptr(envv, &env, ptr_size);
5976 		if (error) {
5977 			goto bad;
5978 		}
5979 
5980 		envv += ptr_size;
5981 		if (env == 0LL) {
5982 			break;
5983 		}
5984 		/*
5985 		 * av[n...] = env[n]
5986 		 */
5987 		error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
5988 		if (error) {
5989 			goto bad;
5990 		}
5991 		if (imgp->ip_argspace < new_ptr_size) {
5992 			error = E2BIG;
5993 			goto bad;
5994 		}
5995 		imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
5996 		imgp->ip_envc++;
5997 	}
5998 
5999 	/* Save space for envv[] NULL terminator */
6000 	if (imgp->ip_argspace < new_ptr_size) {
6001 		error = E2BIG;
6002 		goto bad;
6003 	}
6004 	imgp->ip_argspace -= new_ptr_size;
6005 
6006 	/* Align the tail of the combined argv+envv area */
6007 	while (imgp->ip_strspace % new_ptr_size != 0) {
6008 		if (imgp->ip_argspace < 1) {
6009 			error = E2BIG;
6010 			goto bad;
6011 		}
6012 		*imgp->ip_strendp++ = '\0';
6013 		imgp->ip_strspace--;
6014 		imgp->ip_argspace--;
6015 	}
6016 
6017 	/* Note where the envv ends and applev begins. */
6018 	imgp->ip_endenvv = imgp->ip_strendp;
6019 
6020 	/*
6021 	 * From now on, we are no longer charging argument
6022 	 * space to ip_argspace.
6023 	 */
6024 
6025 bad:
6026 	return error;
6027 }
6028 
6029 /*
6030  * Libc has an 8-element array set up for stack guard values.  It only fills
6031  * in one of those entries, and both gcc and llvm seem to use only a single
6032  * 8-byte guard.  Until somebody needs more than an 8-byte guard value, don't
6033  * do the work to construct them.
6034  */
6035 #define GUARD_VALUES 1
6036 #define GUARD_KEY "stack_guard="
6037 
6038 /*
6039  * System malloc needs some entropy when it is initialized.
6040  */
6041 #define ENTROPY_VALUES 2
6042 #define ENTROPY_KEY "malloc_entropy="
6043 
6044 /*
6045  * libplatform needs a random pointer-obfuscation value when it is initialized.
6046  */
6047 #define PTR_MUNGE_VALUES 1
6048 #define PTR_MUNGE_KEY "ptr_munge="
6049 
6050 /*
6051  * System malloc engages nanozone for UIAPP.
6052  */
6053 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
6054 
6055 /*
6056  * Used to pass experiment flags up to libmalloc.
6057  */
6058 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
6059 
6060 /*
6061  * Passes information about hardened runtime entitlements to libsystem/libmalloc
6062  */
6063 #define HARDENED_RUNTIME_KEY "HardenedRuntime="
6064 
6065 #define PFZ_KEY "pfz="
6066 extern user32_addr_t commpage_text32_location;
6067 extern user64_addr_t commpage_text64_location;
6068 
6069 extern uuid_string_t bootsessionuuid_string;
6070 static TUNABLE(uint32_t, exe_boothash_salt, "exe_boothash_salt", 0);
6071 
6072 __startup_func
6073 static void
exe_boothash_salt_generate(void)6074 exe_boothash_salt_generate(void)
6075 {
6076 	if (!PE_parse_boot_argn("exe_boothash_salt", NULL, 0)) {
6077 		read_random(&exe_boothash_salt, sizeof(exe_boothash_salt));
6078 	}
6079 }
6080 STARTUP(EARLY_BOOT, STARTUP_RANK_MIDDLE, exe_boothash_salt_generate);
6081 
6082 
6083 #define MAIN_STACK_VALUES 4
6084 #define MAIN_STACK_KEY "main_stack="
6085 
6086 #define FSID_KEY "executable_file="
6087 #define DYLD_FSID_KEY "dyld_file="
6088 #define CDHASH_KEY "executable_cdhash="
6089 #define DYLD_FLAGS_KEY "dyld_flags="
6090 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
6091 #define APP_BOOT_SESSION_KEY "executable_boothash="
6092 #if __has_feature(ptrauth_calls)
6093 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
6094 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
6095 #endif /* __has_feature(ptrauth_calls) */
6096 #define MAIN_TH_PORT_KEY "th_port="
6097 
6098 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
6099 
6100 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
6101 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
6102 
6103 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6104 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
6105 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6106 
6107 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)6108 exec_add_entropy_key(struct image_params *imgp,
6109     const char *key,
6110     int values,
6111     boolean_t embedNUL)
6112 {
6113 	const int limit = 8;
6114 	uint64_t entropy[limit];
6115 	char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
6116 	if (values > limit) {
6117 		values = limit;
6118 	}
6119 
6120 	read_random(entropy, sizeof(entropy[0]) * values);
6121 
6122 	if (embedNUL) {
6123 		entropy[0] &= ~(0xffull << 8);
6124 	}
6125 
6126 	int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
6127 	size_t remaining = sizeof(str) - len;
6128 	for (int i = 1; i < values && remaining > 0; ++i) {
6129 		size_t start = sizeof(str) - remaining;
6130 		len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
6131 		remaining -= len;
6132 	}
6133 
6134 	return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
6135 }
6136 
6137 /*
6138  * Build up the contents of the apple[] string vector
6139  */
6140 #if (DEVELOPMENT || DEBUG)
6141 extern uint64_t dyld_flags;
6142 #endif
6143 
6144 #if __has_feature(ptrauth_calls)
6145 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)6146 is_arm64e_running_as_arm64(const struct image_params *imgp)
6147 {
6148 	return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
6149 	       (imgp->ip_flags & IMGPF_NOJOP);
6150 }
6151 #endif /* __has_feature(ptrauth_calls) */
6152 
6153 _Atomic uint64_t libmalloc_experiment_factors = 0;
6154 
6155 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result)6156 exec_add_apple_strings(struct image_params *imgp,
6157     const load_result_t *load_result)
6158 {
6159 	int error;
6160 	int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6161 	thread_t new_thread;
6162 	ipc_port_t sright;
6163 	uint64_t local_experiment_factors = 0;
6164 
6165 	/* exec_save_path stored the first string */
6166 	imgp->ip_applec = 1;
6167 
6168 	/* adding the pfz string */
6169 	{
6170 		char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
6171 
6172 		if (img_ptr_size == 8) {
6173 			__assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
6174 			assert(ret < sizeof(pfz_string));
6175 		} else {
6176 			snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
6177 		}
6178 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
6179 		if (error) {
6180 			printf("Failed to add the pfz string with error %d\n", error);
6181 			goto bad;
6182 		}
6183 		imgp->ip_applec++;
6184 	}
6185 
6186 	/* adding the NANO_ENGAGE_KEY key */
6187 	if (imgp->ip_px_sa) {
6188 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6189 		int proc_flags = psa->psa_flags;
6190 
6191 		if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
6192 			const char *nano_string = NANO_ENGAGE_KEY;
6193 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
6194 			if (error) {
6195 				goto bad;
6196 			}
6197 			imgp->ip_applec++;
6198 		}
6199 	}
6200 
6201 	/*
6202 	 * Supply libc with a collection of random values to use when
6203 	 * implementing -fstack-protector.
6204 	 *
6205 	 * (The first random string always contains an embedded NUL so that
6206 	 * __stack_chk_guard also protects against C string vulnerabilities)
6207 	 */
6208 	error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
6209 	if (error) {
6210 		goto bad;
6211 	}
6212 	imgp->ip_applec++;
6213 
6214 	/*
6215 	 * Supply libc with entropy for system malloc.
6216 	 */
6217 	error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
6218 	if (error) {
6219 		goto bad;
6220 	}
6221 	imgp->ip_applec++;
6222 
6223 	/*
6224 	 * Supply libpthread & libplatform with a random value to use for pointer
6225 	 * obfuscation.
6226 	 */
6227 	error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
6228 	if (error) {
6229 		goto bad;
6230 	}
6231 	imgp->ip_applec++;
6232 
6233 	/*
6234 	 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
6235 	 * stack if it was allocated by the kernel.
6236 	 *
6237 	 * The guard page is not included in this stack size as libpthread
6238 	 * expects to add it back in after receiving this value.
6239 	 */
6240 	if (load_result->unixproc) {
6241 		char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
6242 		snprintf(stack_string, sizeof(stack_string),
6243 		    MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
6244 		    (uint64_t)load_result->user_stack,
6245 		    (uint64_t)load_result->user_stack_size,
6246 		    (uint64_t)load_result->user_stack_alloc,
6247 		    (uint64_t)load_result->user_stack_alloc_size);
6248 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
6249 		if (error) {
6250 			goto bad;
6251 		}
6252 		imgp->ip_applec++;
6253 	}
6254 
6255 	if (imgp->ip_vattr) {
6256 		uint64_t fsid    = vnode_get_va_fsid(imgp->ip_vattr);
6257 		uint64_t fsobjid = imgp->ip_vattr->va_fileid;
6258 
6259 		char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6260 		snprintf(fsid_string, sizeof(fsid_string),
6261 		    FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
6262 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6263 		if (error) {
6264 			goto bad;
6265 		}
6266 		imgp->ip_applec++;
6267 	}
6268 
6269 	if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
6270 		char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6271 		snprintf(fsid_string, sizeof(fsid_string),
6272 		    DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
6273 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6274 		if (error) {
6275 			goto bad;
6276 		}
6277 		imgp->ip_applec++;
6278 	}
6279 
6280 	uint8_t cdhash[SHA1_RESULTLEN];
6281 	int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash);
6282 	if (cdhash_errror == 0) {
6283 		char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
6284 		strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
6285 		char *p = hash_string + sizeof(CDHASH_KEY) - 1;
6286 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6287 			snprintf(p, 3, "%02x", (int) cdhash[i]);
6288 			p += 2;
6289 		}
6290 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
6291 		if (error) {
6292 			goto bad;
6293 		}
6294 		imgp->ip_applec++;
6295 
6296 		/* hash together cd-hash and boot-session-uuid */
6297 		uint8_t sha_digest[SHA256_DIGEST_LENGTH];
6298 		SHA256_CTX sha_ctx;
6299 		SHA256_Init(&sha_ctx);
6300 		SHA256_Update(&sha_ctx, &exe_boothash_salt, sizeof(exe_boothash_salt));
6301 		SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
6302 		SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
6303 		SHA256_Final(sha_digest, &sha_ctx);
6304 		char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
6305 		strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
6306 		char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
6307 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6308 			snprintf(s, 3, "%02x", (int) sha_digest[i]);
6309 			s += 2;
6310 		}
6311 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
6312 		if (error) {
6313 			goto bad;
6314 		}
6315 		imgp->ip_applec++;
6316 	}
6317 #if (DEVELOPMENT || DEBUG)
6318 	if (dyld_flags) {
6319 		char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
6320 		snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
6321 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
6322 		if (error) {
6323 			goto bad;
6324 		}
6325 		imgp->ip_applec++;
6326 	}
6327 #endif
6328 	if (imgp->ip_subsystem_root_path) {
6329 		size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
6330 		char subsystem_root_path_string[buffer_len];
6331 		int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
6332 
6333 		if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
6334 			error = ENAMETOOLONG;
6335 			goto bad;
6336 		}
6337 
6338 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
6339 		if (error) {
6340 			goto bad;
6341 		}
6342 
6343 		imgp->ip_applec++;
6344 	}
6345 #if __has_feature(ptrauth_calls)
6346 	if (is_arm64e_running_as_arm64(imgp)) {
6347 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
6348 		if (error) {
6349 			goto bad;
6350 		}
6351 
6352 		imgp->ip_applec++;
6353 	}
6354 #endif /* __has_feature(ptrauth_calls) */
6355 
6356 
6357 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
6358 	{
6359 		char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
6360 		strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
6361 		bool allowAll = bootarg_arm64e_preview_abi;
6362 		strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
6363 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
6364 		if (error) {
6365 			goto bad;
6366 		}
6367 
6368 		imgp->ip_applec++;
6369 	}
6370 #endif
6371 	/*
6372 	 * Add main thread mach port name
6373 	 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
6374 	 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
6375 	 * against libpthread.
6376 	 */
6377 	if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
6378 		thread_reference(new_thread);
6379 		sright = convert_thread_to_port_pinned(new_thread);
6380 		task_t new_task = get_threadtask(new_thread);
6381 		mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
6382 		char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
6383 		snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
6384 
6385 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
6386 		if (error) {
6387 			goto bad;
6388 		}
6389 		imgp->ip_applec++;
6390 	}
6391 
6392 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6393 	if (imgp->ip_px_sa != NULL) {
6394 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6395 		if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
6396 			const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
6397 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
6398 			if (error) {
6399 				goto bad;
6400 			}
6401 			imgp->ip_applec++;
6402 		}
6403 	}
6404 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6405 
6406 	/* adding the libmalloc experiment string */
6407 	local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
6408 	if (__improbable(local_experiment_factors != 0)) {
6409 		char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
6410 
6411 		snprintf(
6412 			libmalloc_experiment_factors_string,
6413 			sizeof(libmalloc_experiment_factors_string),
6414 			LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
6415 			local_experiment_factors);
6416 		error = exec_add_user_string(
6417 			imgp,
6418 			CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
6419 			UIO_SYSSPACE,
6420 			FALSE);
6421 		if (error) {
6422 			printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
6423 			goto bad;
6424 		}
6425 		imgp->ip_applec++;
6426 	}
6427 
6428 
6429 	/* tell dyld that it can leverage hardware for its read-only/read-write trusted path */
6430 	if (imgp->ip_flags & IMGPF_HW_TPRO) {
6431 		const char *dyld_hw_tpro = "dyld_hw_tpro=1";
6432 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_hw_tpro), UIO_SYSSPACE, FALSE);
6433 		if (error) {
6434 			printf("Failed to add dyld hw tpro setting with error %d\n", error);
6435 			goto bad;
6436 		}
6437 
6438 		imgp->ip_applec++;
6439 
6440 	}
6441 
6442 	if (load_result->hardened_runtime_binary) {
6443 		const size_t HR_STRING_SIZE = sizeof(HARDENED_RUNTIME_KEY) + HR_FLAGS_NUM_NIBBLES + 2 + 1;
6444 		char hardened_runtime[HR_STRING_SIZE];
6445 		snprintf(hardened_runtime, HR_STRING_SIZE, HARDENED_RUNTIME_KEY"0x%x", load_result->hardened_runtime_binary);
6446 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hardened_runtime), UIO_SYSSPACE, FALSE);
6447 		if (error) {
6448 			printf("Failed to add hardened runtime flag with error %d\n", error);
6449 			goto bad;
6450 		}
6451 		imgp->ip_applec++;
6452 	}
6453 	/* Align the tail of the combined applev area */
6454 	while (imgp->ip_strspace % img_ptr_size != 0) {
6455 		*imgp->ip_strendp++ = '\0';
6456 		imgp->ip_strspace--;
6457 	}
6458 
6459 bad:
6460 	return error;
6461 }
6462 
6463 /*
6464  * exec_check_permissions
6465  *
6466  * Description:	Verify that the file that is being attempted to be executed
6467  *		is in fact allowed to be executed based on it POSIX file
6468  *		permissions and other access control criteria
6469  *
6470  * Parameters:	struct image_params *	the image parameter block
6471  *
6472  * Returns:	0			Success
6473  *		EACCES			Permission denied
6474  *		ENOEXEC			Executable file format error
6475  *		ETXTBSY			Text file busy [misuse of error code]
6476  *	vnode_getattr:???
6477  *	vnode_authorize:???
6478  */
6479 static int
exec_check_permissions(struct image_params * imgp)6480 exec_check_permissions(struct image_params *imgp)
6481 {
6482 	struct vnode *vp = imgp->ip_vp;
6483 	struct vnode_attr *vap = imgp->ip_vattr;
6484 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6485 	int error;
6486 	kauth_action_t action;
6487 
6488 	/* Only allow execution of regular files */
6489 	if (!vnode_isreg(vp)) {
6490 		return EACCES;
6491 	}
6492 
6493 	/* Get the file attributes that we will be using here and elsewhere */
6494 	VATTR_INIT(vap);
6495 	VATTR_WANTED(vap, va_uid);
6496 	VATTR_WANTED(vap, va_gid);
6497 	VATTR_WANTED(vap, va_mode);
6498 	VATTR_WANTED(vap, va_fsid);
6499 	VATTR_WANTED(vap, va_fsid64);
6500 	VATTR_WANTED(vap, va_fileid);
6501 	VATTR_WANTED(vap, va_data_size);
6502 	if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
6503 		return error;
6504 	}
6505 
6506 	/*
6507 	 * Ensure that at least one execute bit is on - otherwise root
6508 	 * will always succeed, and we don't want to happen unless the
6509 	 * file really is executable.
6510 	 */
6511 	if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
6512 		return EACCES;
6513 	}
6514 
6515 	/* Disallow zero length files */
6516 	if (vap->va_data_size == 0) {
6517 		return ENOEXEC;
6518 	}
6519 
6520 	imgp->ip_arch_offset = (user_size_t)0;
6521 #if __LP64__
6522 	imgp->ip_arch_size = vap->va_data_size;
6523 #else
6524 	if (vap->va_data_size > UINT32_MAX) {
6525 		return ENOEXEC;
6526 	}
6527 	imgp->ip_arch_size = (user_size_t)vap->va_data_size;
6528 #endif
6529 
6530 	/* Disable setuid-ness for traced programs or if MNT_NOSUID */
6531 	if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
6532 		vap->va_mode &= ~(VSUID | VSGID);
6533 	}
6534 
6535 	/*
6536 	 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
6537 	 * flags for setuid/setgid binaries.
6538 	 */
6539 	if (vap->va_mode & (VSUID | VSGID)) {
6540 		imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
6541 	}
6542 
6543 #if CONFIG_MACF
6544 	error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
6545 	if (error) {
6546 		return error;
6547 	}
6548 #endif
6549 
6550 	/* Check for execute permission */
6551 	action = KAUTH_VNODE_EXECUTE;
6552 	/* Traced images must also be readable */
6553 	if (p->p_lflag & P_LTRACED) {
6554 		action |= KAUTH_VNODE_READ_DATA;
6555 	}
6556 	if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
6557 		return error;
6558 	}
6559 
6560 #if 0
6561 	/* Don't let it run if anyone had it open for writing */
6562 	vnode_lock(vp);
6563 	if (vp->v_writecount) {
6564 		panic("going to return ETXTBSY %x", vp);
6565 		vnode_unlock(vp);
6566 		return ETXTBSY;
6567 	}
6568 	vnode_unlock(vp);
6569 #endif
6570 
6571 	/* XXX May want to indicate to underlying FS that vnode is open */
6572 
6573 	return error;
6574 }
6575 
6576 
6577 /*
6578  * exec_handle_sugid
6579  *
6580  * Initially clear the P_SUGID in the process flags; if an SUGID process is
6581  * exec'ing a non-SUGID image, then  this is the point of no return.
6582  *
6583  * If the image being activated is SUGID, then replace the credential with a
6584  * copy, disable tracing (unless the tracing process is root), reset the
6585  * mach task port to revoke it, set the P_SUGID bit,
6586  *
6587  * If the saved user and group ID will be changing, then make sure it happens
6588  * to a new credential, rather than a shared one.
6589  *
6590  * Set the security token (this is probably obsolete, given that the token
6591  * should not technically be separate from the credential itself).
6592  *
6593  * Parameters:	struct image_params *	the image parameter block
6594  *
6595  * Returns:	void			No failure indication
6596  *
6597  * Implicit returns:
6598  *		<process credential>	Potentially modified/replaced
6599  *		<task port>		Potentially revoked
6600  *		<process flags>		P_SUGID bit potentially modified
6601  *		<security token>	Potentially modified
6602  */
6603 __attribute__((noinline))
6604 static int
exec_handle_sugid(struct image_params * imgp)6605 exec_handle_sugid(struct image_params *imgp)
6606 {
6607 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
6608 	kauth_cred_t            cred = vfs_context_ucred(imgp->ip_vfs_context);
6609 	int                     i;
6610 	int                     leave_sugid_clear = 0;
6611 	int                     mac_reset_ipc = 0;
6612 	int                     error = 0;
6613 #if CONFIG_MACF
6614 	int                     mac_transition, disjoint_cred = 0;
6615 	int             label_update_return = 0;
6616 
6617 	/*
6618 	 * Determine whether a call to update the MAC label will result in the
6619 	 * credential changing.
6620 	 *
6621 	 * Note:	MAC policies which do not actually end up modifying
6622 	 *		the label subsequently are strongly encouraged to
6623 	 *		return 0 for this check, since a non-zero answer will
6624 	 *		slow down the exec fast path for normal binaries.
6625 	 */
6626 	mac_transition = mac_cred_check_label_update_execve(
6627 		imgp->ip_vfs_context,
6628 		imgp->ip_vp,
6629 		imgp->ip_arch_offset,
6630 		imgp->ip_scriptvp,
6631 		imgp->ip_scriptlabelp,
6632 		imgp->ip_execlabelp,
6633 		p,
6634 		&imgp->ip_px_smpx);
6635 #endif
6636 
6637 	OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
6638 
6639 	/*
6640 	 * Order of the following is important; group checks must go last,
6641 	 * as we use the success of the 'ismember' check combined with the
6642 	 * failure of the explicit match to indicate that we will be setting
6643 	 * the egid of the process even though the new process did not
6644 	 * require VSUID/VSGID bits in order for it to set the new group as
6645 	 * its egid.
6646 	 *
6647 	 * Note:	Technically, by this we are implying a call to
6648 	 *		setegid() in the new process, rather than implying
6649 	 *		it used its VSGID bit to set the effective group,
6650 	 *		even though there is no code in that process to make
6651 	 *		such a call.
6652 	 */
6653 	if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
6654 	    kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
6655 	    ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
6656 	    ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
6657 	    (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
6658 #if CONFIG_MACF
6659 /* label for MAC transition and neither VSUID nor VSGID */
6660 handle_mac_transition:
6661 #endif
6662 
6663 #if CONFIG_SETUID
6664 		/*
6665 		 * Replace the credential with a copy of itself if euid or
6666 		 * egid change.
6667 		 *
6668 		 * Note:	setuid binaries will automatically opt out of
6669 		 *		group resolver participation as a side effect
6670 		 *		of this operation.  This is an intentional
6671 		 *		part of the security model, which requires a
6672 		 *		participating credential be established by
6673 		 *		escalating privilege, setting up all other
6674 		 *		aspects of the credential including whether
6675 		 *		or not to participate in external group
6676 		 *		membership resolution, then dropping their
6677 		 *		effective privilege to that of the desired
6678 		 *		final credential state.
6679 		 *
6680 		 * Modifications to p_ucred must be guarded using the
6681 		 * proc's ucred lock. This prevents others from accessing
6682 		 * a garbage credential.
6683 		 */
6684 
6685 		if (imgp->ip_origvattr->va_mode & VSUID) {
6686 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6687 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6688 				return kauth_cred_model_setresuid(model,
6689 				KAUTH_UID_NONE,
6690 				imgp->ip_origvattr->va_uid,
6691 				imgp->ip_origvattr->va_uid,
6692 				KAUTH_UID_NONE);
6693 			});
6694 		}
6695 
6696 		if (imgp->ip_origvattr->va_mode & VSGID) {
6697 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6698 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6699 				return kauth_cred_model_setresgid(model,
6700 				KAUTH_GID_NONE,
6701 				imgp->ip_origvattr->va_gid,
6702 				imgp->ip_origvattr->va_gid);
6703 			});
6704 		}
6705 #endif /* CONFIG_SETUID */
6706 
6707 #if CONFIG_MACF
6708 		/*
6709 		 * If a policy has indicated that it will transition the label,
6710 		 * before making the call into the MAC policies, get a new
6711 		 * duplicate credential, so they can modify it without
6712 		 * modifying any others sharing it.
6713 		 */
6714 		if (mac_transition) {
6715 			/*
6716 			 * This hook may generate upcalls that require
6717 			 * importance donation from the kernel.
6718 			 * (23925818)
6719 			 */
6720 			thread_t thread = current_thread();
6721 			thread_enable_send_importance(thread, TRUE);
6722 			kauth_proc_label_update_execve(p,
6723 			    imgp->ip_vfs_context,
6724 			    imgp->ip_vp,
6725 			    imgp->ip_arch_offset,
6726 			    imgp->ip_scriptvp,
6727 			    imgp->ip_scriptlabelp,
6728 			    imgp->ip_execlabelp,
6729 			    &imgp->ip_csflags,
6730 			    &imgp->ip_px_smpx,
6731 			    &disjoint_cred,                     /* will be non zero if disjoint */
6732 			    &label_update_return);
6733 			thread_enable_send_importance(thread, FALSE);
6734 
6735 			if (disjoint_cred) {
6736 				/*
6737 				 * If updating the MAC label resulted in a
6738 				 * disjoint credential, flag that we need to
6739 				 * set the P_SUGID bit.  This protects
6740 				 * against debuggers being attached by an
6741 				 * insufficiently privileged process onto the
6742 				 * result of a transition to a more privileged
6743 				 * credential.
6744 				 */
6745 				leave_sugid_clear = 0;
6746 			}
6747 
6748 			imgp->ip_mac_return = label_update_return;
6749 		}
6750 
6751 		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);
6752 
6753 #endif  /* CONFIG_MACF */
6754 
6755 		/*
6756 		 * If 'leave_sugid_clear' is non-zero, then we passed the
6757 		 * VSUID and MACF checks, and successfully determined that
6758 		 * the previous cred was a member of the VSGID group, but
6759 		 * that it was not the default at the time of the execve,
6760 		 * and that the post-labelling credential was not disjoint.
6761 		 * So we don't set the P_SUGID or reset mach ports and fds
6762 		 * on the basis of simply running this code.
6763 		 */
6764 		if (mac_reset_ipc || !leave_sugid_clear) {
6765 			/*
6766 			 * Have mach reset the task and thread ports.
6767 			 * We don't want anyone who had the ports before
6768 			 * a setuid exec to be able to access/control the
6769 			 * task/thread after.
6770 			 */
6771 			ipc_task_reset((imgp->ip_new_thread != NULL) ?
6772 			    get_threadtask(imgp->ip_new_thread) : proc_task(p));
6773 			ipc_thread_reset((imgp->ip_new_thread != NULL) ?
6774 			    imgp->ip_new_thread : current_thread());
6775 		}
6776 
6777 		if (!leave_sugid_clear) {
6778 			/*
6779 			 * Flag the process as setuid.
6780 			 */
6781 			OSBitOrAtomic(P_SUGID, &p->p_flag);
6782 
6783 			/*
6784 			 * Radar 2261856; setuid security hole fix
6785 			 * XXX For setuid processes, attempt to ensure that
6786 			 * stdin, stdout, and stderr are already allocated.
6787 			 * We do not want userland to accidentally allocate
6788 			 * descriptors in this range which has implied meaning
6789 			 * to libc.
6790 			 */
6791 			for (i = 0; i < 3; i++) {
6792 				if (fp_get_noref_locked(p, i) != NULL) {
6793 					continue;
6794 				}
6795 
6796 				/*
6797 				 * Do the kernel equivalent of
6798 				 *
6799 				 *      if i == 0
6800 				 *              (void) open("/dev/null", O_RDONLY);
6801 				 *      else
6802 				 *              (void) open("/dev/null", O_WRONLY);
6803 				 */
6804 
6805 				struct fileproc *fp;
6806 				int indx;
6807 				int flag;
6808 				struct nameidata *ndp = NULL;
6809 
6810 				if (i == 0) {
6811 					flag = FREAD;
6812 				} else {
6813 					flag = FWRITE;
6814 				}
6815 
6816 				if ((error = falloc_exec(p, imgp->ip_vfs_context,
6817 				    &fp, &indx)) != 0) {
6818 					continue;
6819 				}
6820 
6821 				ndp = kalloc_type(struct nameidata,
6822 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
6823 
6824 				NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
6825 				    CAST_USER_ADDR_T("/dev/null"),
6826 				    imgp->ip_vfs_context);
6827 
6828 				if ((error = vn_open(ndp, flag, 0)) != 0) {
6829 					fp_free(p, indx, fp);
6830 					kfree_type(struct nameidata, ndp);
6831 					break;
6832 				}
6833 
6834 				struct fileglob *fg = fp->fp_glob;
6835 
6836 				fg->fg_flag = flag;
6837 				fg->fg_ops = &vnops;
6838 				fp_set_data(fp, ndp->ni_vp);
6839 
6840 				vnode_put(ndp->ni_vp);
6841 
6842 				proc_fdlock(p);
6843 				procfdtbl_releasefd(p, indx, NULL);
6844 				fp_drop(p, indx, fp, 1);
6845 				proc_fdunlock(p);
6846 
6847 				kfree_type(struct nameidata, ndp);
6848 			}
6849 		}
6850 	}
6851 #if CONFIG_MACF
6852 	else {
6853 		/*
6854 		 * We are here because we were told that the MAC label will
6855 		 * be transitioned, and the binary is not VSUID or VSGID; to
6856 		 * deal with this case, we could either duplicate a lot of
6857 		 * code, or we can indicate we want to default the P_SUGID
6858 		 * bit clear and jump back up.
6859 		 */
6860 		if (mac_transition) {
6861 			leave_sugid_clear = 1;
6862 			goto handle_mac_transition;
6863 		}
6864 	}
6865 
6866 #endif  /* CONFIG_MACF */
6867 
6868 	/* Update the process' identity version and set the security token */
6869 	proc_setpidversion(p, OSIncrementAtomic(&nextpidversion));
6870 	task_set_uniqueid(proc_task(p));
6871 
6872 	/*
6873 	 * Implement the semantic where the effective user and group become
6874 	 * the saved user and group in exec'ed programs.
6875 	 */
6876 	kauth_cred_proc_update(p, PROC_SETTOKEN_ALWAYS,
6877 	    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6878 		posix_cred_t pcred = posix_cred_get(model);
6879 
6880 		if (pcred->cr_svuid == pcred->cr_uid &&
6881 		pcred->cr_svgid == pcred->cr_gid) {
6882 		        return false;
6883 		}
6884 
6885 		pcred->cr_svuid = pcred->cr_uid;
6886 		pcred->cr_svgid = pcred->cr_gid;
6887 		return true;
6888 	});
6889 
6890 	return error;
6891 }
6892 
6893 
6894 /*
6895  * create_unix_stack
6896  *
6897  * Description:	Set the user stack address for the process to the provided
6898  *		address.  If a custom stack was not set as a result of the
6899  *		load process (i.e. as specified by the image file for the
6900  *		executable), then allocate the stack in the provided map and
6901  *		set up appropriate guard pages for enforcing administrative
6902  *		limits on stack growth, if they end up being needed.
6903  *
6904  * Parameters:	p			Process to set stack on
6905  *		load_result		Information from mach-o load commands
6906  *		map			Address map in which to allocate the new stack
6907  *
6908  * Returns:	KERN_SUCCESS		Stack successfully created
6909  *		!KERN_SUCCESS		Mach failure code
6910  */
6911 __attribute__((noinline))
6912 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)6913 create_unix_stack(vm_map_t map, load_result_t* load_result,
6914     proc_t p)
6915 {
6916 	mach_vm_size_t          size, prot_size;
6917 	mach_vm_offset_t        addr, prot_addr;
6918 	kern_return_t           kr;
6919 
6920 	mach_vm_address_t       user_stack = load_result->user_stack;
6921 
6922 	proc_lock(p);
6923 	p->user_stack = (uintptr_t)user_stack;
6924 	if (load_result->custom_stack) {
6925 		p->p_lflag |= P_LCUSTOM_STACK;
6926 	}
6927 	proc_unlock(p);
6928 	if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
6929 		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);
6930 	}
6931 
6932 	if (load_result->user_stack_alloc_size > 0) {
6933 		/*
6934 		 * Allocate enough space for the maximum stack size we
6935 		 * will ever authorize and an extra page to act as
6936 		 * a guard page for stack overflows. For default stacks,
6937 		 * vm_initial_limit_stack takes care of the extra guard page.
6938 		 * Otherwise we must allocate it ourselves.
6939 		 */
6940 		if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
6941 			return KERN_INVALID_ARGUMENT;
6942 		}
6943 		addr = vm_map_trunc_page(load_result->user_stack - size,
6944 		    vm_map_page_mask(map));
6945 		kr = mach_vm_allocate_kernel(map, &addr, size,
6946 		    VM_FLAGS_FIXED, VM_MEMORY_STACK);
6947 		if (kr != KERN_SUCCESS) {
6948 			// Can't allocate at default location, try anywhere
6949 			addr = 0;
6950 			kr = mach_vm_allocate_kernel(map, &addr, size,
6951 			    VM_FLAGS_ANYWHERE, VM_MEMORY_STACK);
6952 			if (kr != KERN_SUCCESS) {
6953 				return kr;
6954 			}
6955 
6956 			user_stack = addr + size;
6957 			load_result->user_stack = (user_addr_t)user_stack;
6958 
6959 			proc_lock(p);
6960 			p->user_stack = (uintptr_t)user_stack;
6961 			proc_unlock(p);
6962 		}
6963 
6964 		load_result->user_stack_alloc = (user_addr_t)addr;
6965 
6966 		/*
6967 		 * And prevent access to what's above the current stack
6968 		 * size limit for this process.
6969 		 */
6970 		if (load_result->user_stack_size == 0) {
6971 			load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
6972 			prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
6973 		} else {
6974 			prot_size = PAGE_SIZE;
6975 		}
6976 
6977 		prot_addr = addr;
6978 		kr = mach_vm_protect(map,
6979 		    prot_addr,
6980 		    prot_size,
6981 		    FALSE,
6982 		    VM_PROT_NONE);
6983 		if (kr != KERN_SUCCESS) {
6984 			(void)mach_vm_deallocate(map, addr, size);
6985 			return kr;
6986 		}
6987 	}
6988 
6989 	return KERN_SUCCESS;
6990 }
6991 
6992 #include <sys/reboot.h>
6993 
6994 /*
6995  * load_init_program_at_path
6996  *
6997  * Description:	Load the "init" program; in most cases, this will be "launchd"
6998  *
6999  * Parameters:	p			Process to call execve() to create
7000  *					the "init" program
7001  *		scratch_addr		Page in p, scratch space
7002  *		path			NULL terminated path
7003  *
7004  * Returns:	KERN_SUCCESS		Success
7005  *		!KERN_SUCCESS           See execve/mac_execve for error codes
7006  *
7007  * Notes:	The process that is passed in is the first manufactured
7008  *		process on the system, and gets here via bsd_ast() firing
7009  *		for the first time.  This is done to ensure that bsd_init()
7010  *		has run to completion.
7011  *
7012  *		The address map of the first manufactured process matches the
7013  *		word width of the kernel. Once the self-exec completes, the
7014  *		initproc might be different.
7015  */
7016 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)7017 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
7018 {
7019 	int retval[2];
7020 	int error;
7021 	struct execve_args init_exec_args;
7022 	user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
7023 
7024 	/*
7025 	 * Validate inputs and pre-conditions
7026 	 */
7027 	assert(p);
7028 	assert(scratch_addr);
7029 	assert(path);
7030 
7031 	/*
7032 	 * Copy out program name.
7033 	 */
7034 	size_t path_length = strlen(path) + 1;
7035 	argv0 = scratch_addr;
7036 	error = copyout(path, argv0, path_length);
7037 	if (error) {
7038 		return error;
7039 	}
7040 
7041 	scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
7042 
7043 	/*
7044 	 * Put out first (and only) argument, similarly.
7045 	 * Assumes everything fits in a page as allocated above.
7046 	 */
7047 	if (boothowto & RB_SINGLE) {
7048 		const char *init_args = "-s";
7049 		size_t init_args_length = strlen(init_args) + 1;
7050 
7051 		argv1 = scratch_addr;
7052 		error = copyout(init_args, argv1, init_args_length);
7053 		if (error) {
7054 			return error;
7055 		}
7056 
7057 		scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
7058 	}
7059 
7060 	if (proc_is64bit(p)) {
7061 		user64_addr_t argv64bit[3] = {};
7062 
7063 		argv64bit[0] = argv0;
7064 		argv64bit[1] = argv1;
7065 		argv64bit[2] = USER_ADDR_NULL;
7066 
7067 		error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
7068 		if (error) {
7069 			return error;
7070 		}
7071 	} else {
7072 		user32_addr_t argv32bit[3] = {};
7073 
7074 		argv32bit[0] = (user32_addr_t)argv0;
7075 		argv32bit[1] = (user32_addr_t)argv1;
7076 		argv32bit[2] = USER_ADDR_NULL;
7077 
7078 		error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
7079 		if (error) {
7080 			return error;
7081 		}
7082 	}
7083 
7084 	/*
7085 	 * Set up argument block for fake call to execve.
7086 	 */
7087 	init_exec_args.fname = argv0;
7088 	init_exec_args.argp = scratch_addr;
7089 	init_exec_args.envp = USER_ADDR_NULL;
7090 
7091 	/*
7092 	 * So that init task is set with uid,gid 0 token
7093 	 *
7094 	 * The access to the cred is safe:
7095 	 * the proc isn't running yet, it's stable.
7096 	 */
7097 	set_security_token(p, proc_ucred_unsafe(p));
7098 
7099 	return execve(p, &init_exec_args, retval);
7100 }
7101 
7102 static const char * init_programs[] = {
7103 #if DEBUG
7104 	"/usr/appleinternal/sbin/launchd.debug",
7105 #endif
7106 #if DEVELOPMENT || DEBUG
7107 	"/usr/appleinternal/sbin/launchd.development",
7108 #endif
7109 	"/sbin/launchd",
7110 };
7111 
7112 /*
7113  * load_init_program
7114  *
7115  * Description:	Load the "init" program; in most cases, this will be "launchd"
7116  *
7117  * Parameters:	p			Process to call execve() to create
7118  *					the "init" program
7119  *
7120  * Returns:	(void)
7121  *
7122  * Notes:	The process that is passed in is the first manufactured
7123  *		process on the system, and gets here via bsd_ast() firing
7124  *		for the first time.  This is done to ensure that bsd_init()
7125  *		has run to completion.
7126  *
7127  *		In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
7128  *		may be used to select a specific launchd executable. As with
7129  *		the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
7130  *		will force /sbin/launchd to be selected.
7131  *
7132  *              Search order by build:
7133  *
7134  * DEBUG	DEVELOPMENT	RELEASE		PATH
7135  * ----------------------------------------------------------------------------------
7136  * 1		1		NA		/usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
7137  * 2		NA		NA		/usr/appleinternal/sbin/launchd.debug
7138  * 3		2		NA		/usr/appleinternal/sbin/launchd.development
7139  * 4		3		1		/sbin/launchd
7140  */
7141 void
load_init_program(proc_t p)7142 load_init_program(proc_t p)
7143 {
7144 	uint32_t i;
7145 	int error;
7146 	vm_map_t map = current_map();
7147 	mach_vm_offset_t scratch_addr = 0;
7148 	mach_vm_size_t map_page_size = vm_map_page_size(map);
7149 
7150 	(void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size, VM_FLAGS_ANYWHERE, VM_KERN_MEMORY_NONE);
7151 #if CONFIG_MEMORYSTATUS
7152 	(void) memorystatus_init_at_boot_snapshot();
7153 #endif /* CONFIG_MEMORYSTATUS */
7154 
7155 #if DEBUG || DEVELOPMENT
7156 	/* Check for boot-arg suffix first */
7157 	char launchd_suffix[64];
7158 	if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
7159 		char launchd_path[128];
7160 		boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
7161 		    (strcmp(launchd_suffix, "release") == 0));
7162 
7163 		if (is_release_suffix) {
7164 			printf("load_init_program: attempting to load /sbin/launchd\n");
7165 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
7166 			if (!error) {
7167 				return;
7168 			}
7169 
7170 			panic("Process 1 exec of launchd.release failed, errno %d", error);
7171 		} else {
7172 			strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
7173 			strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
7174 
7175 			printf("load_init_program: attempting to load %s\n", launchd_path);
7176 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
7177 			if (!error) {
7178 				return;
7179 			} else if (error != ENOENT) {
7180 				printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
7181 			}
7182 		}
7183 	}
7184 #endif
7185 
7186 	error = ENOENT;
7187 	for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
7188 		printf("load_init_program: attempting to load %s\n", init_programs[i]);
7189 		error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
7190 		if (!error) {
7191 			return;
7192 		} else if (error != ENOENT) {
7193 			printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
7194 		}
7195 	}
7196 
7197 	panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
7198 }
7199 
7200 /*
7201  * load_return_to_errno
7202  *
7203  * Description:	Convert a load_return_t (Mach error) to an errno (BSD error)
7204  *
7205  * Parameters:	lrtn			Mach error number
7206  *
7207  * Returns:	(int)			BSD error number
7208  *		0			Success
7209  *		EBADARCH		Bad architecture
7210  *		EBADMACHO		Bad Mach object file
7211  *		ESHLIBVERS		Bad shared library version
7212  *		ENOMEM			Out of memory/resource shortage
7213  *		EACCES			Access denied
7214  *		ENOENT			Entry not found (usually "file does
7215  *					does not exist")
7216  *		EIO			An I/O error occurred
7217  *		EBADEXEC		The executable is corrupt/unknown
7218  */
7219 static int
load_return_to_errno(load_return_t lrtn)7220 load_return_to_errno(load_return_t lrtn)
7221 {
7222 	switch (lrtn) {
7223 	case LOAD_SUCCESS:
7224 		return 0;
7225 	case LOAD_BADARCH:
7226 		return EBADARCH;
7227 	case LOAD_BADMACHO:
7228 	case LOAD_BADMACHO_UPX:
7229 		return EBADMACHO;
7230 	case LOAD_SHLIB:
7231 		return ESHLIBVERS;
7232 	case LOAD_NOSPACE:
7233 	case LOAD_RESOURCE:
7234 		return ENOMEM;
7235 	case LOAD_PROTECT:
7236 		return EACCES;
7237 	case LOAD_ENOENT:
7238 		return ENOENT;
7239 	case LOAD_IOERROR:
7240 		return EIO;
7241 	case LOAD_DECRYPTFAIL:
7242 		return EAUTH;
7243 	case LOAD_FAILURE:
7244 	default:
7245 		return EBADEXEC;
7246 	}
7247 }
7248 
7249 #include <mach/mach_types.h>
7250 #include <mach/vm_prot.h>
7251 #include <mach/semaphore.h>
7252 #include <mach/sync_policy.h>
7253 #include <kern/clock.h>
7254 #include <mach/kern_return.h>
7255 
7256 /*
7257  * execargs_alloc
7258  *
7259  * Description:	Allocate the block of memory used by the execve arguments.
7260  *		At the same time, we allocate a page so that we can read in
7261  *		the first page of the image.
7262  *
7263  * Parameters:	struct image_params *	the image parameter block
7264  *
7265  * Returns:	0			Success
7266  *		EINVAL			Invalid argument
7267  *		EACCES			Permission denied
7268  *		EINTR			Interrupted function
7269  *		ENOMEM			Not enough space
7270  *
7271  * Notes:	This is a temporary allocation into the kernel address space
7272  *		to enable us to copy arguments in from user space.  This is
7273  *		necessitated by not mapping the process calling execve() into
7274  *		the kernel address space during the execve() system call.
7275  *
7276  *		We assemble the argument and environment, etc., into this
7277  *		region before copying it as a single block into the child
7278  *		process address space (at the top or bottom of the stack,
7279  *		depending on which way the stack grows; see the function
7280  *		exec_copyout_strings() for details).
7281  *
7282  *		This ends up with a second (possibly unnecessary) copy compared
7283  *		with assembing the data directly into the child address space,
7284  *		instead, but since we cannot be guaranteed that the parent has
7285  *		not modified its environment, we can't really know that it's
7286  *		really a block there as well.
7287  */
7288 
7289 
7290 static int execargs_waiters = 0;
7291 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
7292 
7293 static void
execargs_lock_lock(void)7294 execargs_lock_lock(void)
7295 {
7296 	lck_mtx_lock_spin(&execargs_cache_lock);
7297 }
7298 
7299 static void
execargs_lock_unlock(void)7300 execargs_lock_unlock(void)
7301 {
7302 	lck_mtx_unlock(&execargs_cache_lock);
7303 }
7304 
7305 static wait_result_t
execargs_lock_sleep(void)7306 execargs_lock_sleep(void)
7307 {
7308 	return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
7309 }
7310 
7311 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)7312 execargs_purgeable_allocate(char **execarg_address)
7313 {
7314 	mach_vm_offset_t addr = 0;
7315 	kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
7316 	    BSD_PAGEABLE_SIZE_PER_EXEC, VM_FLAGS_ANYWHERE | VM_FLAGS_PURGABLE,
7317 	    VM_KERN_MEMORY_NONE);
7318 	*execarg_address = (char *)addr;
7319 	assert(kr == KERN_SUCCESS);
7320 	return kr;
7321 }
7322 
7323 static kern_return_t
execargs_purgeable_reference(void * execarg_address)7324 execargs_purgeable_reference(void *execarg_address)
7325 {
7326 	int state = VM_PURGABLE_NONVOLATILE;
7327 	kern_return_t kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7328 
7329 	assert(kr == KERN_SUCCESS);
7330 	return kr;
7331 }
7332 
7333 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)7334 execargs_purgeable_volatilize(void *execarg_address)
7335 {
7336 	int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
7337 	kern_return_t kr;
7338 	kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7339 
7340 	assert(kr == KERN_SUCCESS);
7341 
7342 	return kr;
7343 }
7344 
7345 static void
execargs_wakeup_waiters(void)7346 execargs_wakeup_waiters(void)
7347 {
7348 	thread_wakeup(&execargs_free_count);
7349 }
7350 
7351 static int
execargs_alloc(struct image_params * imgp)7352 execargs_alloc(struct image_params *imgp)
7353 {
7354 	kern_return_t kret;
7355 	wait_result_t res;
7356 	int i, cache_index = -1;
7357 
7358 	execargs_lock_lock();
7359 
7360 	while (execargs_free_count == 0) {
7361 		execargs_waiters++;
7362 		res = execargs_lock_sleep();
7363 		execargs_waiters--;
7364 		if (res != THREAD_AWAKENED) {
7365 			execargs_lock_unlock();
7366 			return EINTR;
7367 		}
7368 	}
7369 
7370 	execargs_free_count--;
7371 
7372 	for (i = 0; i < execargs_cache_size; i++) {
7373 		vm_offset_t element = execargs_cache[i];
7374 		if (element) {
7375 			cache_index = i;
7376 			imgp->ip_strings = (char *)(execargs_cache[i]);
7377 			execargs_cache[i] = 0;
7378 			break;
7379 		}
7380 	}
7381 
7382 	assert(execargs_free_count >= 0);
7383 
7384 	execargs_lock_unlock();
7385 
7386 	if (cache_index == -1) {
7387 		kret = execargs_purgeable_allocate(&imgp->ip_strings);
7388 	} else {
7389 		kret = execargs_purgeable_reference(imgp->ip_strings);
7390 	}
7391 
7392 	assert(kret == KERN_SUCCESS);
7393 	if (kret != KERN_SUCCESS) {
7394 		return ENOMEM;
7395 	}
7396 
7397 	/* last page used to read in file headers */
7398 	imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
7399 	imgp->ip_strendp = imgp->ip_strings;
7400 	imgp->ip_argspace = NCARGS;
7401 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
7402 
7403 	return 0;
7404 }
7405 
7406 /*
7407  * execargs_free
7408  *
7409  * Description:	Free the block of memory used by the execve arguments and the
7410  *		first page of the executable by a previous call to the function
7411  *		execargs_alloc().
7412  *
7413  * Parameters:	struct image_params *	the image parameter block
7414  *
7415  * Returns:	0			Success
7416  *		EINVAL			Invalid argument
7417  *		EINTR			Oeration interrupted
7418  */
7419 static int
execargs_free(struct image_params * imgp)7420 execargs_free(struct image_params *imgp)
7421 {
7422 	kern_return_t kret;
7423 	int i;
7424 	boolean_t needs_wakeup = FALSE;
7425 
7426 	kret = execargs_purgeable_volatilize(imgp->ip_strings);
7427 
7428 	execargs_lock_lock();
7429 	execargs_free_count++;
7430 
7431 	for (i = 0; i < execargs_cache_size; i++) {
7432 		vm_offset_t element = execargs_cache[i];
7433 		if (element == 0) {
7434 			execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
7435 			imgp->ip_strings = NULL;
7436 			break;
7437 		}
7438 	}
7439 
7440 	assert(imgp->ip_strings == NULL);
7441 
7442 	if (execargs_waiters > 0) {
7443 		needs_wakeup = TRUE;
7444 	}
7445 
7446 	execargs_lock_unlock();
7447 
7448 	if (needs_wakeup == TRUE) {
7449 		execargs_wakeup_waiters();
7450 	}
7451 
7452 	return kret == KERN_SUCCESS ? 0 : EINVAL;
7453 }
7454 
7455 void
uthread_set_exec_data(struct uthread * uth,struct image_params * imgp)7456 uthread_set_exec_data(struct uthread *uth, struct image_params *imgp)
7457 {
7458 	uth->uu_save.uus_exec_data.imgp = imgp;
7459 }
7460 
7461 size_t
thread_get_current_exec_path(char * path,size_t size)7462 thread_get_current_exec_path(char *path, size_t size)
7463 {
7464 	struct uthread *uth = current_uthread();
7465 	struct image_params *imgp = uth->uu_save.uus_exec_data.imgp;
7466 	size_t string_size = 0;
7467 	char *exec_path;
7468 
7469 	if (path == NULL || imgp == NULL || imgp->ip_strings == NULL) {
7470 		return 0;
7471 	}
7472 
7473 	exec_path = imgp->ip_strings + strlen(EXECUTABLE_KEY);
7474 	string_size = imgp->ip_strendp - exec_path;
7475 	string_size = MIN(MAXPATHLEN, string_size);
7476 	string_size = MIN(size, string_size);
7477 
7478 	string_size = strlcpy(path, exec_path, string_size);
7479 	return string_size;
7480 }
7481 static void
exec_resettextvp(proc_t p,struct image_params * imgp)7482 exec_resettextvp(proc_t p, struct image_params *imgp)
7483 {
7484 	vnode_t vp;
7485 	off_t offset;
7486 	vnode_t tvp  = p->p_textvp;
7487 	int ret;
7488 
7489 	vp = imgp->ip_vp;
7490 	offset = imgp->ip_arch_offset;
7491 
7492 	if (vp == NULLVP) {
7493 		panic("exec_resettextvp: expected valid vp");
7494 	}
7495 
7496 	ret = vnode_ref(vp);
7497 	proc_lock(p);
7498 	if (ret == 0) {
7499 		p->p_textvp = vp;
7500 		p->p_textoff = offset;
7501 	} else {
7502 		p->p_textvp = NULLVP;   /* this is paranoia */
7503 		p->p_textoff = 0;
7504 	}
7505 	proc_unlock(p);
7506 
7507 	if (tvp != NULLVP) {
7508 		if (vnode_getwithref(tvp) == 0) {
7509 			vnode_rele(tvp);
7510 			vnode_put(tvp);
7511 		}
7512 	}
7513 }
7514 
7515 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
7516 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
7517 
7518 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)7519 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
7520 {
7521 	static char const nibble[] = "0123456789abcdef";
7522 
7523 	/* Apparently still the safest way to get a hex representation
7524 	 * of binary data.
7525 	 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
7526 	 * <rdar://problem/33328859> confusion around %*D/%nD in printf
7527 	 */
7528 	for (int i = 0; i < CS_CDHASH_LEN; ++i) {
7529 		str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
7530 		str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
7531 	}
7532 	str[CS_CDHASH_STRING_SIZE - 1] = 0;
7533 }
7534 
7535 /*
7536  * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
7537  *
7538  * Description: Waits for the userspace daemon to respond to the request
7539  *              we made. Function declared non inline to be visible in
7540  *		stackshots and spindumps as well as debugging.
7541  */
7542 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)7543 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
7544 {
7545 	return find_code_signature(task_access_port, new_pid);
7546 }
7547 
7548 /*
7549  * Update signature dependent process state, called by
7550  * process_signature.
7551  */
7552 static int
proc_process_signature(proc_t p,os_reason_t * signature_failure_reason)7553 proc_process_signature(proc_t p, os_reason_t *signature_failure_reason)
7554 {
7555 	int error = 0;
7556 	char const *error_msg = NULL;
7557 
7558 	kern_return_t kr = machine_task_process_signature(proc_get_task_raw(p), proc_platform(p), proc_sdk(p), &error_msg);
7559 
7560 	if (kr != KERN_SUCCESS) {
7561 		error = EINVAL;
7562 
7563 		if (error_msg != NULL) {
7564 			uint32_t error_msg_len = (uint32_t)strlen(error_msg) + 1;
7565 			mach_vm_address_t data_addr = 0;
7566 			int reason_error = 0;
7567 			int kcdata_error = 0;
7568 
7569 			os_reason_t reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7570 			reason->osr_flags = OS_REASON_FLAG_GENERATE_CRASH_REPORT | OS_REASON_FLAG_CONSISTENT_FAILURE;
7571 
7572 			if ((reason_error = os_reason_alloc_buffer_noblock(reason,
7573 			    kcdata_estimate_required_buffer_size(1, error_msg_len))) == 0 &&
7574 			    (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
7575 			    EXIT_REASON_USER_DESC, error_msg_len,
7576 			    &data_addr)) == KERN_SUCCESS) {
7577 				kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
7578 				    error_msg, error_msg_len);
7579 
7580 				if (mc_error != KERN_SUCCESS) {
7581 					printf("process_signature: failed to copy reason string (kcdata_memcpy error: %d)\n",
7582 					    mc_error);
7583 				}
7584 			} else {
7585 				printf("failed to allocate space for reason string (os_reason_alloc_buffer error: %d, kcdata error: %d, length: %u)\n",
7586 				    reason_error, kcdata_error, error_msg_len);
7587 			}
7588 
7589 			assert(*signature_failure_reason == NULL); // shouldn't have gotten so far
7590 			*signature_failure_reason = reason;
7591 		}
7592 	}
7593 	return error;
7594 }
7595 
7596 static int
process_signature(proc_t p,struct image_params * imgp)7597 process_signature(proc_t p, struct image_params *imgp)
7598 {
7599 	mach_port_t port = IPC_PORT_NULL;
7600 	kern_return_t kr = KERN_FAILURE;
7601 	int error = EACCES;
7602 	boolean_t unexpected_failure = FALSE;
7603 	struct cs_blob *csb;
7604 	boolean_t require_success = FALSE;
7605 	int spawn = (imgp->ip_flags & IMGPF_SPAWN);
7606 	const int vfexec = 0;
7607 	os_reason_t signature_failure_reason = OS_REASON_NULL;
7608 
7609 	/*
7610 	 * Override inherited code signing flags with the
7611 	 * ones for the process that is being successfully
7612 	 * loaded
7613 	 */
7614 	proc_lock(p);
7615 	proc_csflags_update(p, imgp->ip_csflags);
7616 	proc_unlock(p);
7617 
7618 	/* Set the switch_protect flag on the map */
7619 	if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
7620 		vm_map_switch_protect(get_task_map(proc_task(p)), TRUE);
7621 	}
7622 	/* set the cs_enforced flags in the map */
7623 	if (proc_getcsflags(p) & CS_ENFORCEMENT) {
7624 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), TRUE);
7625 	} else {
7626 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), FALSE);
7627 	}
7628 
7629 	/*
7630 	 * image activation may be failed due to policy
7631 	 * which is unexpected but security framework does not
7632 	 * approve of exec, kill and return immediately.
7633 	 */
7634 	if (imgp->ip_mac_return != 0) {
7635 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7636 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
7637 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7638 		error = imgp->ip_mac_return;
7639 		unexpected_failure = TRUE;
7640 		goto done;
7641 	}
7642 
7643 	if (imgp->ip_cs_error != OS_REASON_NULL) {
7644 		signature_failure_reason = imgp->ip_cs_error;
7645 		imgp->ip_cs_error = OS_REASON_NULL;
7646 		error = EACCES;
7647 		goto done;
7648 	}
7649 
7650 	/* call the launch constraints hook */
7651 	os_reason_t launch_constraint_reason;
7652 	if ((error = mac_proc_check_launch_constraints(p, imgp, &launch_constraint_reason)) != 0) {
7653 		signature_failure_reason = launch_constraint_reason;
7654 		goto done;
7655 	}
7656 
7657 #if XNU_TARGET_OS_OSX
7658 	/* Check for platform passed in spawn attr if iOS binary is being spawned */
7659 	if (proc_platform(p) == PLATFORM_IOS) {
7660 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
7661 		if (psa == NULL || psa->psa_platform == 0) {
7662 			boolean_t no_sandbox_entitled = FALSE;
7663 #if DEBUG || DEVELOPMENT
7664 			/*
7665 			 * Allow iOS binaries to spawn on internal systems
7666 			 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
7667 			 * boot-arg set to true
7668 			 */
7669 			if (unentitled_ios_sim_launch) {
7670 				no_sandbox_entitled = TRUE;
7671 			} else {
7672 				no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
7673 				    (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
7674 			}
7675 #endif /* DEBUG || DEVELOPMENT */
7676 			if (!no_sandbox_entitled) {
7677 				signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7678 				    EXEC_EXIT_REASON_WRONG_PLATFORM);
7679 				error = EACCES;
7680 				goto done;
7681 			}
7682 			printf("Allowing spawn of iOS binary %s since it has "
7683 			    "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
7684 			    "boot-arg set to true\n", p->p_name);
7685 		} else if (psa->psa_platform != PLATFORM_IOS) {
7686 			/* Simulator binary spawned with wrong platform */
7687 			signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7688 			    EXEC_EXIT_REASON_WRONG_PLATFORM);
7689 			error = EACCES;
7690 			goto done;
7691 		} else {
7692 			printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
7693 			    p->p_name);
7694 		}
7695 	}
7696 #endif /* XNU_TARGET_OS_OSX */
7697 
7698 	/* If the code signature came through the image activation path, we skip the
7699 	 * taskgated / externally attached path. */
7700 	if (imgp->ip_csflags & CS_SIGNED) {
7701 		error = 0;
7702 		goto done;
7703 	}
7704 
7705 	/* The rest of the code is for signatures that either already have been externally
7706 	 * attached (likely, but not necessarily by a previous run through the taskgated
7707 	 * path), or that will now be attached by taskgated. */
7708 
7709 	kr = task_get_task_access_port(proc_task(p), &port);
7710 	if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
7711 		error = 0;
7712 		if (require_success) {
7713 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7714 			    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
7715 			signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
7716 			error = EACCES;
7717 		}
7718 		goto done;
7719 	}
7720 
7721 	/*
7722 	 * taskgated returns KERN_SUCCESS if it has completed its work
7723 	 * and the exec should continue, KERN_FAILURE if the exec should
7724 	 * fail, or it may error out with different error code in an
7725 	 * event of mig failure (e.g. process was signalled during the
7726 	 * rpc call, taskgated died, mig server died etc.).
7727 	 */
7728 
7729 	kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
7730 	switch (kr) {
7731 	case KERN_SUCCESS:
7732 		error = 0;
7733 		break;
7734 	case KERN_FAILURE:
7735 		error = EACCES;
7736 
7737 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7738 		    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
7739 		signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
7740 		goto done;
7741 	default:
7742 		error = EACCES;
7743 
7744 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7745 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
7746 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
7747 		unexpected_failure = TRUE;
7748 		goto done;
7749 	}
7750 
7751 	/* Only do this if exec_resettextvp() did not fail */
7752 	if (p->p_textvp != NULLVP) {
7753 		csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
7754 
7755 		if (csb != NULL) {
7756 			/* As the enforcement we can do here is very limited, we only allow things that
7757 			 * are the only reason why this code path still exists:
7758 			 * Adhoc signed non-platform binaries without special cs_flags and without any
7759 			 * entitlements (unrestricted ones still pass AMFI). */
7760 			if (
7761 				/* Revalidate the blob if necessary through bumped generation count. */
7762 				(ubc_cs_generation_check(p->p_textvp) == 0 ||
7763 				ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
7764 				/* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
7765 				(csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
7766 				/* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
7767 				csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
7768 				CSSLOT_SIGNATURESLOT,
7769 				CSMAGIC_BLOBWRAPPER) == NULL &&
7770 				/* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
7771 				csb->csb_platform_binary == 0 &&
7772 				/* No entitlements, not even unrestricted ones. */
7773 				csb->csb_entitlements_blob == NULL &&
7774 				csb->csb_der_entitlements_blob == NULL) {
7775 				proc_lock(p);
7776 				proc_csflags_set(p, CS_SIGNED | CS_VALID);
7777 				proc_unlock(p);
7778 			} else {
7779 				uint8_t cdhash[CS_CDHASH_LEN];
7780 				char cdhash_string[CS_CDHASH_STRING_SIZE];
7781 				proc_getcdhash(p, cdhash);
7782 				cdhash_to_string(cdhash_string, cdhash);
7783 				printf("ignoring detached code signature on '%s' with cdhash '%s' "
7784 				    "because it is invalid, or not a simple adhoc signature.\n",
7785 				    p->p_name, cdhash_string);
7786 			}
7787 		}
7788 	}
7789 
7790 done:
7791 	if (0 == error) {
7792 		/*
7793 		 * Update the new process's signature-dependent process state.
7794 		 * state.
7795 		 */
7796 
7797 		error = proc_process_signature(p, &signature_failure_reason);
7798 	}
7799 
7800 	if (0 == error) {
7801 		/*
7802 		 * Update the new main thread's signature-dependent thread
7803 		 * state. This was also called when the thread was created,
7804 		 * but for the main thread the signature was not yet attached
7805 		 * at that time.
7806 		 */
7807 		kr = thread_process_signature(imgp->ip_new_thread, proc_get_task_raw(p));
7808 
7809 		if (kr != KERN_SUCCESS) {
7810 			error = EINVAL;
7811 			signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MACHINE_THREAD);
7812 		}
7813 	}
7814 
7815 	if (0 == error) {
7816 		/* The process's code signature related properties are
7817 		 * fully set up, so this is an opportune moment to log
7818 		 * platform binary execution, if desired. */
7819 		if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
7820 			uint8_t cdhash[CS_CDHASH_LEN];
7821 			char cdhash_string[CS_CDHASH_STRING_SIZE];
7822 			proc_getcdhash(p, cdhash);
7823 			cdhash_to_string(cdhash_string, cdhash);
7824 
7825 			os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
7826 			    "'%s' with cdhash %s\n", p->p_name, cdhash_string);
7827 		}
7828 	} else {
7829 		if (!unexpected_failure) {
7830 			proc_csflags_set(p, CS_KILLED);
7831 		}
7832 		/* make very sure execution fails */
7833 		if (vfexec || spawn) {
7834 			assert(signature_failure_reason != OS_REASON_NULL);
7835 			psignal_vfork_with_reason(p, proc_task(p), imgp->ip_new_thread,
7836 			    SIGKILL, signature_failure_reason);
7837 			signature_failure_reason = OS_REASON_NULL;
7838 			error = 0;
7839 		} else {
7840 			assert(signature_failure_reason != OS_REASON_NULL);
7841 			psignal_with_reason(p, SIGKILL, signature_failure_reason);
7842 			signature_failure_reason = OS_REASON_NULL;
7843 		}
7844 	}
7845 
7846 	if (port != IPC_PORT_NULL) {
7847 		ipc_port_release_send(port);
7848 	}
7849 
7850 	/* If we hit this, we likely would have leaked an exit reason */
7851 	assert(signature_failure_reason == OS_REASON_NULL);
7852 	return error;
7853 }
7854 
7855 /*
7856  * Typically as soon as we start executing this process, the
7857  * first instruction will trigger a VM fault to bring the text
7858  * pages (as executable) into the address space, followed soon
7859  * thereafter by dyld data structures (for dynamic executable).
7860  * To optimize this, as well as improve support for hardware
7861  * debuggers that can only access resident pages present
7862  * in the process' page tables, we prefault some pages if
7863  * possible. Errors are non-fatal.
7864  */
7865 #ifndef PREVENT_CALLER_STACK_USE
7866 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
7867 #endif
7868 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(proc_t p __unused,struct image_params * imgp,load_result_t * load_result)7869 exec_prefault_data(proc_t p __unused, struct image_params *imgp, load_result_t *load_result)
7870 {
7871 	int ret;
7872 	size_t expected_all_image_infos_size;
7873 	kern_return_t kr;
7874 
7875 	/*
7876 	 * Prefault executable or dyld entry point.
7877 	 */
7878 	if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7879 		DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
7880 	}
7881 	kr = vm_fault(current_map(),
7882 	    vm_map_trunc_page(load_result->entry_point,
7883 	    vm_map_page_mask(current_map())),
7884 	    VM_PROT_READ | VM_PROT_EXECUTE,
7885 	    FALSE, VM_KERN_MEMORY_NONE,
7886 	    THREAD_UNINT, NULL, 0);
7887 	if (kr != KERN_SUCCESS) {
7888 		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);
7889 	}
7890 
7891 	if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7892 		expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
7893 	} else {
7894 		expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
7895 	}
7896 
7897 	/* Decode dyld anchor structure from <mach-o/dyld_images.h> */
7898 	if (load_result->dynlinker &&
7899 	    load_result->all_image_info_addr &&
7900 	    load_result->all_image_info_size >= expected_all_image_infos_size) {
7901 		union {
7902 			struct user64_dyld_all_image_infos      infos64;
7903 			struct user32_dyld_all_image_infos      infos32;
7904 		} all_image_infos;
7905 
7906 		/*
7907 		 * Pre-fault to avoid copyin() going through the trap handler
7908 		 * and recovery path.
7909 		 */
7910 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7911 			DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
7912 		}
7913 		kr = vm_fault(current_map(),
7914 		    vm_map_trunc_page(load_result->all_image_info_addr,
7915 		    vm_map_page_mask(current_map())),
7916 		    VM_PROT_READ | VM_PROT_WRITE,
7917 		    FALSE, VM_KERN_MEMORY_NONE,
7918 		    THREAD_UNINT, NULL, 0);
7919 		if (kr != KERN_SUCCESS) {
7920 //			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);
7921 		}
7922 		if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
7923 			/* all_image_infos straddles a page */
7924 			kr = vm_fault(current_map(),
7925 			    vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
7926 			    vm_map_page_mask(current_map())),
7927 			    VM_PROT_READ | VM_PROT_WRITE,
7928 			    FALSE, VM_KERN_MEMORY_NONE,
7929 			    THREAD_UNINT, NULL, 0);
7930 			if (kr != KERN_SUCCESS) {
7931 //				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);
7932 			}
7933 		}
7934 
7935 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7936 			DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
7937 		}
7938 		ret = copyin((user_addr_t)load_result->all_image_info_addr,
7939 		    &all_image_infos,
7940 		    expected_all_image_infos_size);
7941 		if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
7942 			user_addr_t notification_address;
7943 			user_addr_t dyld_image_address;
7944 			user_addr_t dyld_version_address;
7945 			user_addr_t dyld_all_image_infos_address;
7946 			user_addr_t dyld_slide_amount;
7947 
7948 			if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7949 				notification_address = (user_addr_t)all_image_infos.infos64.notification;
7950 				dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
7951 				dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
7952 				dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
7953 			} else {
7954 				notification_address = all_image_infos.infos32.notification;
7955 				dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
7956 				dyld_version_address = all_image_infos.infos32.dyldVersion;
7957 				dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
7958 			}
7959 
7960 			/*
7961 			 * dyld statically sets up the all_image_infos in its Mach-O
7962 			 * binary at static link time, with pointers relative to its default
7963 			 * load address. Since ASLR might slide dyld before its first
7964 			 * instruction is executed, "dyld_slide_amount" tells us how far
7965 			 * dyld was loaded compared to its default expected load address.
7966 			 * All other pointers into dyld's image should be adjusted by this
7967 			 * amount. At some point later, dyld will fix up pointers to take
7968 			 * into account the slide, at which point the all_image_infos_address
7969 			 * field in the structure will match the runtime load address, and
7970 			 * "dyld_slide_amount" will be 0, if we were to consult it again.
7971 			 */
7972 
7973 			dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
7974 
7975 #if 0
7976 			kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
7977 			    (uint64_t)load_result->all_image_info_addr,
7978 			    all_image_infos.infos32.version,
7979 			    (uint64_t)notification_address,
7980 			    (uint64_t)dyld_image_address,
7981 			    (uint64_t)dyld_version_address,
7982 			    (uint64_t)dyld_all_image_infos_address);
7983 #endif
7984 
7985 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7986 				DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
7987 			}
7988 			kr = vm_fault(current_map(),
7989 			    vm_map_trunc_page(notification_address + dyld_slide_amount,
7990 			    vm_map_page_mask(current_map())),
7991 			    VM_PROT_READ | VM_PROT_EXECUTE,
7992 			    FALSE, VM_KERN_MEMORY_NONE,
7993 			    THREAD_UNINT, NULL, 0);
7994 			if (kr != KERN_SUCCESS) {
7995 //				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);
7996 			}
7997 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7998 				DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
7999 			}
8000 			kr = vm_fault(current_map(),
8001 			    vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
8002 			    vm_map_page_mask(current_map())),
8003 			    VM_PROT_READ | VM_PROT_EXECUTE,
8004 			    FALSE, VM_KERN_MEMORY_NONE,
8005 			    THREAD_UNINT, NULL, 0);
8006 			if (kr != KERN_SUCCESS) {
8007 //				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);
8008 			}
8009 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8010 				DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
8011 			}
8012 			kr = vm_fault(current_map(),
8013 			    vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
8014 			    vm_map_page_mask(current_map())),
8015 			    VM_PROT_READ,
8016 			    FALSE, VM_KERN_MEMORY_NONE,
8017 			    THREAD_UNINT, NULL, 0);
8018 			if (kr != KERN_SUCCESS) {
8019 //				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);
8020 			}
8021 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8022 				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);
8023 			}
8024 			kr = vm_fault(current_map(),
8025 			    vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
8026 			    vm_map_page_mask(current_map())),
8027 			    VM_PROT_READ | VM_PROT_WRITE,
8028 			    FALSE, VM_KERN_MEMORY_NONE,
8029 			    THREAD_UNINT, NULL, 0);
8030 			if (kr != KERN_SUCCESS) {
8031 //				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);
8032 			}
8033 		}
8034 	}
8035 }
8036 
8037 static int
8038 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
8039 {
8040 #pragma unused(oidp, arg2, req)
8041 	int changed;
8042 	errno_t error;
8043 	uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
8044 
8045 	error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
8046 	if (error) {
8047 		return error;
8048 	}
8049 
8050 	if (changed) {
8051 		os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
8052 	}
8053 
8054 	return 0;
8055 }
8056 
8057 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
8058