xref: /xnu-11417.101.15/bsd/kern/kern_exec.c (revision e3723e1f17661b24996789d8afc084c0c3303b26)
1 /*
2  * Copyright (c) 2000-2020 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Mach Operating System
31  * Copyright (c) 1987 Carnegie-Mellon University
32  * All rights reserved.  The CMU software License Agreement specifies
33  * the terms and conditions for use and redistribution.
34  */
35 
36 /*-
37  * Copyright (c) 1982, 1986, 1991, 1993
38  *	The Regents of the University of California.  All rights reserved.
39  * (c) UNIX System Laboratories, Inc.
40  * All or some portions of this file are derived from material licensed
41  * to the University of California by American Telephone and Telegraph
42  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
43  * the permission of UNIX System Laboratories, Inc.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. All advertising materials mentioning features or use of this software
54  *    must display the following acknowledgement:
55  *	This product includes software developed by the University of
56  *	California, Berkeley and its contributors.
57  * 4. Neither the name of the University nor the names of its contributors
58  *    may be used to endorse or promote products derived from this software
59  *    without specific prior written permission.
60  *
61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71  * SUCH DAMAGE.
72  *
73  *	from: @(#)kern_exec.c	8.1 (Berkeley) 6/10/93
74  */
75 /*
76  * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
77  * support for mandatory and extensible security protections.  This notice
78  * is included in support of clause 2.2 (b) of the Apple Public License,
79  * Version 2.0.
80  */
81 #include <machine/reg.h>
82 #include <machine/cpu_capabilities.h>
83 
84 #include <sys/cdefs.h>
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/filedesc.h>
88 #include <sys/kernel.h>
89 #include <sys/proc_internal.h>
90 #include <sys/kauth.h>
91 #include <sys/user.h>
92 #include <sys/socketvar.h>
93 #include <sys/malloc.h>
94 #include <sys/namei.h>
95 #include <sys/mount_internal.h>
96 #include <sys/vnode_internal.h>
97 #include <sys/file_internal.h>
98 #include <sys/stat.h>
99 #include <sys/uio_internal.h>
100 #include <sys/acct.h>
101 #include <sys/exec.h>
102 #include <sys/kdebug.h>
103 #include <sys/signal.h>
104 #include <sys/aio_kern.h>
105 #include <sys/sysproto.h>
106 #include <sys/sysctl.h>
107 #include <sys/persona.h>
108 #include <sys/reason.h>
109 #if SYSV_SHM
110 #include <sys/shm_internal.h>           /* shmexec() */
111 #endif
112 #include <sys/ubc_internal.h>           /* ubc_map() */
113 #include <sys/spawn.h>
114 #include <sys/spawn_internal.h>
115 #include <sys/process_policy.h>
116 #include <sys/codesign.h>
117 #include <sys/random.h>
118 #include <crypto/sha1.h>
119 
120 #include <libkern/libkern.h>
121 #include <libkern/amfi/amfi.h>
122 #include <libkern/crypto/sha2.h>
123 #include <security/audit/audit.h>
124 
125 #include <ipc/ipc_types.h>
126 
127 #include <mach/mach_param.h>
128 #include <mach/mach_types.h>
129 #include <mach/port.h>
130 #include <mach/task.h>
131 #include <mach/task_access.h>
132 #include <mach/thread_act.h>
133 #include <mach/vm_map.h>
134 #include <mach/mach_vm.h>
135 #include <mach/vm_param.h>
136 #include <mach_debug/mach_debug_types.h>
137 
138 #include <kern/sched_prim.h> /* thread_wakeup() */
139 #include <kern/affinity.h>
140 #include <kern/assert.h>
141 #include <kern/ipc_kobject.h>
142 #include <kern/task.h>
143 #include <kern/thread.h>
144 #include <kern/coalition.h>
145 #include <kern/policy_internal.h>
146 #include <kern/kalloc.h>
147 #include <kern/zalloc.h> /* zone_userspace_reboot_checks() */
148 
149 #include <os/log.h>
150 
151 #if CONFIG_MACF
152 #include <security/mac_framework.h>
153 #include <security/mac_mach_internal.h>
154 #endif
155 
156 #if CONFIG_AUDIT
157 #include <bsm/audit_kevents.h>
158 #endif
159 
160 #if CONFIG_ARCADE
161 #include <kern/arcade.h>
162 #endif
163 
164 #include <vm/vm_map_xnu.h>
165 #include <vm/vm_kern_xnu.h>
166 #include <vm/vm_protos.h>
167 #include <vm/vm_fault.h>
168 #include <vm/vm_pageout_xnu.h>
169 #include <vm/pmap.h>
170 #include <vm/vm_reclaim_xnu.h>
171 
172 #include <kdp/kdp_dyld.h>
173 
174 #include <machine/machine_routines.h>
175 #include <machine/pal_routines.h>
176 
177 #include <pexpert/pexpert.h>
178 
179 #if CONFIG_MEMORYSTATUS
180 #include <sys/kern_memorystatus.h>
181 #endif
182 
183 #include <IOKit/IOBSD.h>
184 
185 #include "kern_exec_internal.h"
186 
187 #include <CodeSignature/Entitlements.h>
188 
189 #include <mach/exclaves.h>
190 
191 
192 extern boolean_t vm_darkwake_mode;
193 
194 /* enable crash reports on various exec failures */
195 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
196 
197 #if XNU_TARGET_OS_OSX
198 #if __has_feature(ptrauth_calls)
199 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
200 #endif /* __has_feature(ptrauth_calls) */
201 
202 #if DEBUG || DEVELOPMENT
203 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
204 #endif /* DEBUG || DEVELOPMENT */
205 #endif /* XNU_TARGET_OS_OSX */
206 
207 
208 
209 #if CONFIG_DTRACE
210 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
211 extern void dtrace_proc_exec(proc_t);
212 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
213 
214 /*
215  * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
216  * we will store its value before actually calling it.
217  */
218 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
219 
220 #include <sys/dtrace_ptss.h>
221 #endif
222 
223 #if __has_feature(ptrauth_calls)
224 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
225     "vm_shared_region_per_team_id", 1);
226 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
227     "vm_shared_region_by_entitlement", 1);
228 
229 /* Upon userland request, reslide the shared cache. */
230 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
231     "vm_shared_region_reslide_aslr",
232 #if CONFIG_RESLIDE_SHARED_CACHE
233     1
234 #else
235     0
236 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
237     );
238 
239 /*
240  * Flag to control what processes should get shared cache randomize resliding
241  * after a fault in the shared cache region:
242  *
243  * 0 - all processes get a new randomized slide
244  * 1 - only platform processes get a new randomized slide
245  */
246 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
247     "vm_shared_region_reslide_restrict", 1);
248 
249 #if DEVELOPMENT || DEBUG
250 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
251     CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
252 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
253     CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
254 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
255     CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
256 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
257     CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
258 #endif
259 #endif /* __has_feature(ptrauth_calls) */
260 
261 #if DEVELOPMENT || DEBUG
262 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", true);
263 #else
264 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", false);
265 #endif
266 extern kern_return_t kern_register_userspace_coredump(task_t task, const char * name);
267 #define USERSPACE_COREDUMP_PANIC_ENTITLEMENT "com.apple.private.enable-coredump-on-panic"
268 #define USERSPACE_COREDUMP_PANIC_SEED_ENTITLEMENT \
269 	"com.apple.private.enable-coredump-on-panic-seed-privacy-approved"
270 
271 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
272 extern void task_set_did_exec_flag(task_t task);
273 extern void task_clear_exec_copy_flag(task_t task);
274 proc_t proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task,
275     task_t new_task, struct image_params *imgp, void **inherit);
276 boolean_t task_is_active(task_t);
277 boolean_t thread_is_active(thread_t thread);
278 void thread_copy_resource_info(thread_t dst_thread, thread_t src_thread);
279 void *ipc_importance_exec_switch_task(task_t old_task, task_t new_task);
280 extern void ipc_importance_release(void *elem);
281 extern boolean_t task_has_watchports(task_t task);
282 extern void task_set_no_smt(task_t task);
283 #if defined(HAS_APPLE_PAC)
284 char *task_get_vm_shared_region_id_and_jop_pid(task_t task, uint64_t *jop_pid);
285 #endif
286 task_t convert_port_to_task(ipc_port_t port);
287 
288 #if CONFIG_EXCLAVES
289 int task_add_conclave(task_t task, void *vnode, int64_t off, const char *task_conclave_id);
290 kern_return_t task_inherit_conclave(task_t old_task, task_t new_task, void *vnode, int64_t off);
291 #endif /* CONFIG_EXCLAVES */
292 
293 
294 /*
295  * Mach things for which prototypes are unavailable from Mach headers
296  */
297 extern void ipc_task_enable(task_t task);
298 extern void ipc_task_reset(task_t task);
299 extern void ipc_thread_reset(thread_t thread);
300 
301 #if DEVELOPMENT || DEBUG
302 void task_importance_update_owner_info(task_t);
303 #endif
304 
305 extern struct savearea *get_user_regs(thread_t);
306 
307 __attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
308 
309 #include <kern/thread.h>
310 #include <kern/task.h>
311 #include <kern/ast.h>
312 #include <kern/mach_loader.h>
313 #include <kern/mach_fat.h>
314 #include <mach-o/fat.h>
315 #include <mach-o/loader.h>
316 #include <machine/vmparam.h>
317 #include <sys/imgact.h>
318 
319 #include <sys/sdt.h>
320 
321 
322 /*
323  * EAI_ITERLIMIT	The maximum number of times to iterate an image
324  *			activator in exec_activate_image() before treating
325  *			it as malformed/corrupt.
326  */
327 #define EAI_ITERLIMIT           3
328 
329 /*
330  * For #! interpreter parsing
331  */
332 #define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
333 #define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
334 
335 extern vm_map_t bsd_pageable_map;
336 extern const struct fileops vnops;
337 extern int nextpidversion;
338 
339 
340 #define USER_ADDR_ALIGN(addr, val) \
341 	( ( (user_addr_t)(addr) + (val) - 1) \
342 	        & ~((val) - 1) )
343 
344 /*
345  * For subsystem root support
346  */
347 #define SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT "com.apple.private.spawn-subsystem-root"
348 
349 /*
350  * Allow setting p_crash_behavior to trigger panic on crash
351  */
352 #define SPAWN_SET_PANIC_CRASH_BEHAVIOR "com.apple.private.spawn-panic-crash-behavior"
353 
354 /*
355  * This entitlement marks security critical binaries for which the spawned
356  * process should be hardened. Implies enable-by-default for enablement
357  * of security features. These defaults can be overridden with the control
358  * entitlements for the sub-features below.
359  */
360 #define SPAWN_ENABLE_HARDENED_PROCESS "com.apple.developer.hardened-process"
361 
362 #if DEVELOPMENT || DEBUG
363 /*
364  * The following boot-arg defines the behavior for the case
365  * where a binary entitled as hardened-process but doesn't
366  * have a specific sub-feature entitlement, which is still
367  * under adoption.
368  */
369 typedef enum {
370 	HARDENED_PROCESS_CONFIG_SILENT = 0,
371 	HARDENED_PROCESS_CONFIG_LOG    = 1,
372 	HARDENED_PROCESS_CONFIG_FATAL  = 2,
373 	HARDENED_PROCESS_CONFIG_MAX    = 3
374 } hardened_process_config_policy;
375 
376 TUNABLE(hardened_process_config_policy,
377     hardened_process_config,
378     "hardened_process_config",
379     HARDENED_PROCESS_CONFIG_SILENT);
380 #endif /* DEVELOPMENT || DEBUG */
381 
382 /*
383  * Control entitlement to enable/disable hardened-heap in the process.
384  */
385 #define SPAWN_ENABLE_HARDENED_HEAP "com.apple.developer.hardened-process.hardened-heap"
386 
387 
388 /* Platform Code Exec Logging */
389 static int platform_exec_logging = 0;
390 
391 SYSCTL_DECL(_security_mac);
392 
393 SYSCTL_INT(_security_mac, OID_AUTO, platform_exec_logging, CTLFLAG_RW, &platform_exec_logging, 0,
394     "log cdhashes for all platform binary executions");
395 
396 static os_log_t peLog = OS_LOG_DEFAULT;
397 
398 struct exception_port_action_t {
399 	ipc_port_t port;
400 	_ps_port_action_t *port_action;
401 };
402 
403 struct exec_port_actions {
404 	uint32_t exception_port_count;
405 	uint32_t portwatch_count;
406 	uint32_t registered_count;
407 	struct exception_port_action_t *excport_array;
408 	ipc_port_t *portwatch_array;
409 	ipc_port_t registered_array[TASK_PORT_REGISTER_MAX];
410 };
411 
412 struct image_params;    /* Forward */
413 static int exec_activate_image(struct image_params *imgp);
414 static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
415 static int load_return_to_errno(load_return_t lrtn);
416 static int execargs_alloc(struct image_params *imgp);
417 static int execargs_free(struct image_params *imgp);
418 static int exec_check_permissions(struct image_params *imgp);
419 static int exec_extract_strings(struct image_params *imgp);
420 static int exec_add_apple_strings(struct image_params *imgp, const load_result_t *load_result);
421 static int exec_handle_sugid(struct image_params *imgp);
422 static int sugid_scripts = 0;
423 SYSCTL_INT(_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
424 static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
425 static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
426 static void exec_resettextvp(proc_t, struct image_params *);
427 static int process_signature(proc_t, struct image_params *);
428 static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
429 static errno_t exec_handle_port_actions(struct image_params *imgp,
430     struct exec_port_actions *port_actions);
431 static errno_t exec_handle_exception_port_actions(const struct image_params *imgp,
432     const struct exec_port_actions *port_actions);
433 static errno_t exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
434     task_role_t psa_darwin_role, struct exec_port_actions *port_actions);
435 static void exec_port_actions_destroy(struct exec_port_actions *port_actions);
436 
437 
438 
439 /*
440  * exec_add_user_string
441  *
442  * Add the requested string to the string space area.
443  *
444  * Parameters;	struct image_params *		image parameter block
445  *		user_addr_t			string to add to strings area
446  *		int				segment from which string comes
447  *		boolean_t			TRUE if string contributes to NCARGS
448  *
449  * Returns:	0			Success
450  *		!0			Failure errno from copyinstr()
451  *
452  * Implicit returns:
453  *		(imgp->ip_strendp)	updated location of next add, if any
454  *		(imgp->ip_strspace)	updated byte count of space remaining
455  *		(imgp->ip_argspace) updated byte count of space in NCARGS
456  */
457 __attribute__((noinline))
458 static int
exec_add_user_string(struct image_params * imgp,user_addr_t str,int seg,boolean_t is_ncargs)459 exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
460 {
461 	int error = 0;
462 
463 	do {
464 		size_t len = 0;
465 		int space;
466 
467 		if (is_ncargs) {
468 			space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
469 		} else {
470 			space = imgp->ip_strspace;
471 		}
472 
473 		if (space <= 0) {
474 			error = E2BIG;
475 			break;
476 		}
477 
478 		if (!UIO_SEG_IS_USER_SPACE(seg)) {
479 			char *kstr = CAST_DOWN(char *, str);     /* SAFE */
480 			error = copystr(kstr, imgp->ip_strendp, space, &len);
481 		} else {
482 			error = copyinstr(str, imgp->ip_strendp, space, &len);
483 		}
484 
485 		imgp->ip_strendp += len;
486 		imgp->ip_strspace -= len;
487 		if (is_ncargs) {
488 			imgp->ip_argspace -= len;
489 		}
490 	} while (error == ENAMETOOLONG);
491 
492 	return error;
493 }
494 
495 /*
496  * dyld is now passed the executable path as a getenv-like variable
497  * in the same fashion as the stack_guard and malloc_entropy keys.
498  */
499 #define EXECUTABLE_KEY "executable_path="
500 
501 /*
502  * exec_save_path
503  *
504  * To support new app package launching for Mac OS X, the dyld needs the
505  * first argument to execve() stored on the user stack.
506  *
507  * Save the executable path name at the bottom of the strings area and set
508  * the argument vector pointer to the location following that to indicate
509  * the start of the argument and environment tuples, setting the remaining
510  * string space count to the size of the string area minus the path length.
511  *
512  * Parameters;	struct image_params *		image parameter block
513  *		char *				path used to invoke program
514  *		int				segment from which path comes
515  *
516  * Returns:	int			0	Success
517  *		EFAULT				Bad address
518  *	copy[in]str:EFAULT			Bad address
519  *	copy[in]str:ENAMETOOLONG		Filename too long
520  *
521  * Implicit returns:
522  *		(imgp->ip_strings)		saved path
523  *		(imgp->ip_strspace)		space remaining in ip_strings
524  *		(imgp->ip_strendp)		start of remaining copy area
525  *		(imgp->ip_argspace)		space remaining of NCARGS
526  *		(imgp->ip_applec)		Initial applev[0]
527  *
528  * Note:	We have to do this before the initial namei() since in the
529  *		path contains symbolic links, namei() will overwrite the
530  *		original path buffer contents.  If the last symbolic link
531  *		resolved was a relative pathname, we would lose the original
532  *		"path", which could be an absolute pathname. This might be
533  *		unacceptable for dyld.
534  */
535 static int
exec_save_path(struct image_params * imgp,user_addr_t path,int seg,const char ** excpath)536 exec_save_path(struct image_params *imgp, user_addr_t path, int seg, const char **excpath)
537 {
538 	int error;
539 	size_t len;
540 	char *kpath;
541 
542 	// imgp->ip_strings can come out of a cache, so we need to obliterate the
543 	// old path.
544 	memset(imgp->ip_strings, '\0', strlen(EXECUTABLE_KEY) + MAXPATHLEN);
545 
546 	len = MIN(MAXPATHLEN, imgp->ip_strspace);
547 
548 	switch (seg) {
549 	case UIO_USERSPACE32:
550 	case UIO_USERSPACE64:   /* Same for copyin()... */
551 		error = copyinstr(path, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
552 		break;
553 	case UIO_SYSSPACE:
554 		kpath = CAST_DOWN(char *, path); /* SAFE */
555 		error = copystr(kpath, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
556 		break;
557 	default:
558 		error = EFAULT;
559 		break;
560 	}
561 
562 	if (!error) {
563 		bcopy(EXECUTABLE_KEY, imgp->ip_strings, strlen(EXECUTABLE_KEY));
564 		len += strlen(EXECUTABLE_KEY);
565 
566 		imgp->ip_strendp += len;
567 		imgp->ip_strspace -= len;
568 
569 		if (excpath) {
570 			*excpath = imgp->ip_strings + strlen(EXECUTABLE_KEY);
571 		}
572 	}
573 
574 	return error;
575 }
576 
577 /*
578  * exec_reset_save_path
579  *
580  * If we detect a shell script, we need to reset the string area
581  * state so that the interpreter can be saved onto the stack.
582  *
583  * Parameters;	struct image_params *		image parameter block
584  *
585  * Returns:	int			0	Success
586  *
587  * Implicit returns:
588  *		(imgp->ip_strings)		saved path
589  *		(imgp->ip_strspace)		space remaining in ip_strings
590  *		(imgp->ip_strendp)		start of remaining copy area
591  *		(imgp->ip_argspace)		space remaining of NCARGS
592  *
593  */
594 static int
exec_reset_save_path(struct image_params * imgp)595 exec_reset_save_path(struct image_params *imgp)
596 {
597 	imgp->ip_strendp = imgp->ip_strings;
598 	imgp->ip_argspace = NCARGS;
599 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
600 
601 	return 0;
602 }
603 
604 /*
605  * exec_shell_imgact
606  *
607  * Image activator for interpreter scripts.  If the image begins with
608  * the characters "#!", then it is an interpreter script.  Verify the
609  * length of the script line indicating the interpreter is not in
610  * excess of the maximum allowed size.  If this is the case, then
611  * break out the arguments, if any, which are separated by white
612  * space, and copy them into the argument save area as if they were
613  * provided on the command line before all other arguments.  The line
614  * ends when we encounter a comment character ('#') or newline.
615  *
616  * Parameters;	struct image_params *	image parameter block
617  *
618  * Returns:	-1			not an interpreter (keep looking)
619  *		-3			Success: interpreter: relookup
620  *		>0			Failure: interpreter: error number
621  *
622  * A return value other than -1 indicates subsequent image activators should
623  * not be given the opportunity to attempt to activate the image.
624  */
625 static int
exec_shell_imgact(struct image_params * imgp)626 exec_shell_imgact(struct image_params *imgp)
627 {
628 	char *vdata = imgp->ip_vdata;
629 	char *ihp;
630 	char *line_startp, *line_endp;
631 	char *interp;
632 
633 	/*
634 	 * Make sure it's a shell script.  If we've already redirected
635 	 * from an interpreted file once, don't do it again.
636 	 */
637 	if (vdata[0] != '#' ||
638 	    vdata[1] != '!' ||
639 	    (imgp->ip_flags & IMGPF_INTERPRET) != 0) {
640 		return -1;
641 	}
642 
643 	if (imgp->ip_origcputype != 0) {
644 		/* Fat header previously matched, don't allow shell script inside */
645 		return -1;
646 	}
647 
648 	imgp->ip_flags |= IMGPF_INTERPRET;
649 	imgp->ip_interp_sugid_fd = -1;
650 	imgp->ip_interp_buffer[0] = '\0';
651 
652 	/* Check to see if SUGID scripts are permitted.  If they aren't then
653 	 * clear the SUGID bits.
654 	 * imgp->ip_vattr is known to be valid.
655 	 */
656 	if (sugid_scripts == 0) {
657 		imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
658 	}
659 
660 	/* Try to find the first non-whitespace character */
661 	for (ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++) {
662 		if (IS_EOL(*ihp)) {
663 			/* Did not find interpreter, "#!\n" */
664 			return ENOEXEC;
665 		} else if (IS_WHITESPACE(*ihp)) {
666 			/* Whitespace, like "#!    /bin/sh\n", keep going. */
667 		} else {
668 			/* Found start of interpreter */
669 			break;
670 		}
671 	}
672 
673 	if (ihp == &vdata[IMG_SHSIZE]) {
674 		/* All whitespace, like "#!           " */
675 		return ENOEXEC;
676 	}
677 
678 	line_startp = ihp;
679 
680 	/* Try to find the end of the interpreter+args string */
681 	for (; ihp < &vdata[IMG_SHSIZE]; ihp++) {
682 		if (IS_EOL(*ihp)) {
683 			/* Got it */
684 			break;
685 		} else {
686 			/* Still part of interpreter or args */
687 		}
688 	}
689 
690 	if (ihp == &vdata[IMG_SHSIZE]) {
691 		/* A long line, like "#! blah blah blah" without end */
692 		return ENOEXEC;
693 	}
694 
695 	/* Backtrack until we find the last non-whitespace */
696 	while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
697 		ihp--;
698 	}
699 
700 	/* The character after the last non-whitespace is our logical end of line */
701 	line_endp = ihp + 1;
702 
703 	/*
704 	 * Now we have pointers to the usable part of:
705 	 *
706 	 * "#!  /usr/bin/int first    second   third    \n"
707 	 *      ^ line_startp                       ^ line_endp
708 	 */
709 
710 	/* copy the interpreter name */
711 	interp = imgp->ip_interp_buffer;
712 	for (ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++) {
713 		*interp++ = *ihp;
714 	}
715 	*interp = '\0';
716 
717 	exec_reset_save_path(imgp);
718 	exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
719 	    UIO_SYSSPACE, NULL);
720 
721 	/* Copy the entire interpreter + args for later processing into argv[] */
722 	interp = imgp->ip_interp_buffer;
723 	for (ihp = line_startp; (ihp < line_endp); ihp++) {
724 		*interp++ = *ihp;
725 	}
726 	*interp = '\0';
727 
728 #if CONFIG_SETUID
729 	/*
730 	 * If we have an SUID or SGID script, create a file descriptor
731 	 * from the vnode and pass /dev/fd/%d instead of the actual
732 	 * path name so that the script does not get opened twice
733 	 */
734 	if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
735 		proc_t p;
736 		struct fileproc *fp;
737 		int fd;
738 		int error;
739 
740 		p = vfs_context_proc(imgp->ip_vfs_context);
741 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &fd);
742 		if (error) {
743 			return error;
744 		}
745 
746 		fp->fp_glob->fg_flag = FREAD;
747 		fp->fp_glob->fg_ops = &vnops;
748 		fp_set_data(fp, imgp->ip_vp);
749 
750 		proc_fdlock(p);
751 		procfdtbl_releasefd(p, fd, NULL);
752 		fp_drop(p, fd, fp, 1);
753 		proc_fdunlock(p);
754 		vnode_ref(imgp->ip_vp);
755 
756 		imgp->ip_interp_sugid_fd = fd;
757 	}
758 #endif /* CONFIG_SETUID */
759 
760 	return -3;
761 }
762 
763 
764 
765 /*
766  * exec_fat_imgact
767  *
768  * Image activator for fat 1.0 binaries.  If the binary is fat, then we
769  * need to select an image from it internally, and make that the image
770  * we are going to attempt to execute.  At present, this consists of
771  * reloading the first page for the image with a first page from the
772  * offset location indicated by the fat header.
773  *
774  * Parameters;	struct image_params *	image parameter block
775  *
776  * Returns:	-1			not a fat binary (keep looking)
777  *		-2			Success: encapsulated binary: reread
778  *		>0			Failure: error number
779  *
780  * Important:	This image activator is byte order neutral.
781  *
782  * Note:	A return value other than -1 indicates subsequent image
783  *		activators should not be given the opportunity to attempt
784  *		to activate the image.
785  *
786  *              If we find an encapsulated binary, we make no assertions
787  *		about its  validity; instead, we leave that up to a rescan
788  *		for an activator to claim it, and, if it is claimed by one,
789  *		that activator is responsible for determining validity.
790  */
791 static int
exec_fat_imgact(struct image_params * imgp)792 exec_fat_imgact(struct image_params *imgp)
793 {
794 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
795 	kauth_cred_t cred = kauth_cred_proc_ref(p);
796 	struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
797 	struct _posix_spawnattr *psa = NULL;
798 	struct fat_arch fat_arch;
799 	int resid, error;
800 	load_return_t lret;
801 
802 	if (imgp->ip_origcputype != 0) {
803 		/* Fat header previously matched, don't allow another fat file inside */
804 		error = -1; /* not claimed */
805 		goto bad;
806 	}
807 
808 	/* Make sure it's a fat binary */
809 	if (OSSwapBigToHostInt32(fat_header->magic) != FAT_MAGIC) {
810 		error = -1; /* not claimed */
811 		goto bad;
812 	}
813 
814 	/* imgp->ip_vdata has PAGE_SIZE, zerofilled if the file is smaller */
815 	lret = fatfile_validate_fatarches((vm_offset_t)fat_header, PAGE_SIZE,
816 	    (off_t)imgp->ip_vattr->va_data_size);
817 	if (lret != LOAD_SUCCESS) {
818 		error = load_return_to_errno(lret);
819 		goto bad;
820 	}
821 
822 	/* If posix_spawn binprefs exist, respect those prefs. */
823 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
824 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
825 		uint32_t pr = 0;
826 
827 		/* Check each preference listed against all arches in header */
828 		for (pr = 0; pr < NBINPREFS; pr++) {
829 			cpu_type_t pref = psa->psa_binprefs[pr];
830 			cpu_type_t subpref = psa->psa_subcpuprefs[pr];
831 
832 			if (pref == 0) {
833 				/* No suitable arch in the pref list */
834 				error = EBADARCH;
835 				goto bad;
836 			}
837 
838 			if (pref == CPU_TYPE_ANY) {
839 				/* Fall through to regular grading */
840 				goto regular_grading;
841 			}
842 
843 			lret = fatfile_getbestarch_for_cputype(pref,
844 			    subpref,
845 			    (vm_offset_t)fat_header,
846 			    PAGE_SIZE,
847 			    imgp,
848 			    &fat_arch);
849 			if (lret == LOAD_SUCCESS) {
850 				goto use_arch;
851 			}
852 		}
853 
854 		/* Requested binary preference was not honored */
855 		error = EBADEXEC;
856 		goto bad;
857 	}
858 
859 regular_grading:
860 	/* Look up our preferred architecture in the fat file. */
861 	lret = fatfile_getbestarch((vm_offset_t)fat_header,
862 	    PAGE_SIZE,
863 	    imgp,
864 	    &fat_arch,
865 	    (p->p_flag & P_AFFINITY) != 0);
866 	if (lret != LOAD_SUCCESS) {
867 		error = load_return_to_errno(lret);
868 		goto bad;
869 	}
870 
871 use_arch:
872 	/* Read the Mach-O header out of fat_arch */
873 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
874 	    PAGE_SIZE, fat_arch.offset,
875 	    UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
876 	    cred, &resid, p);
877 	if (error) {
878 		if (error == ERESTART) {
879 			error = EINTR;
880 		}
881 		goto bad;
882 	}
883 
884 	if (resid) {
885 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
886 	}
887 
888 	/* Success.  Indicate we have identified an encapsulated binary */
889 	error = -2;
890 	imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
891 	imgp->ip_arch_size = (user_size_t)fat_arch.size;
892 	imgp->ip_origcputype = fat_arch.cputype;
893 	imgp->ip_origcpusubtype = fat_arch.cpusubtype;
894 
895 bad:
896 	kauth_cred_unref(&cred);
897 	return error;
898 }
899 
900 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)901 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
902 {
903 	int ret;
904 
905 	(void)task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0, false);
906 	task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
907 	if (result->is_64bit_addr) {
908 		OSBitOrAtomic(P_LP64, &p->p_flag);
909 		get_bsdthread_info(thread)->uu_flag |= UT_LP64;
910 	} else {
911 		OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
912 		get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
913 	}
914 	task_set_mach_header_address(task, result->mach_header);
915 
916 	ret = thread_state_initialize(thread);
917 	if (ret != KERN_SUCCESS) {
918 		return ret;
919 	}
920 
921 	if (result->threadstate) {
922 		uint32_t *ts = result->threadstate;
923 		uint32_t total_size = (uint32_t)result->threadstate_sz;
924 
925 		while (total_size > 0) {
926 			uint32_t flavor = *ts++;
927 			uint32_t size = *ts++;
928 
929 			ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
930 			if (ret) {
931 				return ret;
932 			}
933 			ts += size;
934 			total_size -= (size + 2) * sizeof(uint32_t);
935 		}
936 	}
937 
938 	thread_setentrypoint(thread, result->entry_point);
939 
940 	return KERN_SUCCESS;
941 }
942 
943 #if (DEVELOPMENT || DEBUG)
944 extern char panic_on_proc_crash[];
945 extern int use_panic_on_proc_crash;
946 
947 extern char panic_on_proc_exit[];
948 extern int use_panic_on_proc_exit;
949 
950 extern char panic_on_proc_spawn_fail[];
951 extern int use_panic_on_proc_spawn_fail;
952 
953 static inline void
set_crash_behavior_from_bootarg(proc_t p)954 set_crash_behavior_from_bootarg(proc_t p)
955 {
956 	if (use_panic_on_proc_crash && strcmp(p->p_comm, panic_on_proc_crash) == 0) {
957 		printf("will panic on proc crash: %s\n", p->p_comm);
958 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_CRASH;
959 	}
960 
961 	if (use_panic_on_proc_exit && strcmp(p->p_comm, panic_on_proc_exit) == 0) {
962 		printf("will panic on proc exit: %s\n", p->p_comm);
963 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_EXIT;
964 	}
965 
966 	if (use_panic_on_proc_spawn_fail && strcmp(p->p_comm, panic_on_proc_spawn_fail) == 0) {
967 		printf("will panic on proc spawn fail: %s\n", p->p_comm);
968 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_SPAWN_FAIL;
969 	}
970 }
971 #endif
972 
973 void
set_proc_name(struct image_params * imgp,proc_t p)974 set_proc_name(struct image_params *imgp, proc_t p)
975 {
976 	int p_name_len = sizeof(p->p_name) - 1;
977 
978 	if (imgp->ip_ndp->ni_cnd.cn_namelen > p_name_len) {
979 		imgp->ip_ndp->ni_cnd.cn_namelen = p_name_len;
980 	}
981 
982 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name,
983 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
984 	p->p_name[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
985 
986 	if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN) {
987 		imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
988 	}
989 
990 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
991 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
992 	p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
993 
994 #if (DEVELOPMENT || DEBUG)
995 	/*
996 	 * This happens during image activation, so the crash behavior flags from
997 	 * posix_spawn will have already been set. So we don't have to worry about
998 	 * this being overridden.
999 	 */
1000 	set_crash_behavior_from_bootarg(p);
1001 #endif
1002 }
1003 
1004 #if __has_feature(ptrauth_calls)
1005 /**
1006  * Returns a team ID string that may be used to assign a shared region.
1007  *
1008  * Platform binaries do not have team IDs and will return NULL.  Non-platform
1009  * binaries without a team ID will be assigned an artificial team ID of ""
1010  * (empty string) so that they will not be assigned to the default shared
1011  * region.
1012  *
1013  * @param imgp image parameter block
1014  * @return NULL if this is a platform binary, or an appropriate team ID string
1015  *         otherwise
1016  */
1017 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)1018 get_teamid_for_shared_region(struct image_params *imgp)
1019 {
1020 	assert(imgp->ip_vp != NULL);
1021 
1022 	const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
1023 	if (ret) {
1024 		return ret;
1025 	}
1026 
1027 	struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
1028 	if (csblob_get_platform_binary(blob)) {
1029 		return NULL;
1030 	} else {
1031 		static const char *NO_TEAM_ID = "";
1032 		return NO_TEAM_ID;
1033 	}
1034 }
1035 
1036 /**
1037  * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
1038  *
1039  * @param cpusubtype Mach-O style CPU subtype
1040  * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
1041  */
1042 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)1043 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
1044 {
1045 	return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1046 	       CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
1047 }
1048 
1049 #endif /* __has_feature(ptrauth_calls) */
1050 
1051 /**
1052  * Returns whether a type/subtype slice matches the requested
1053  * type/subtype.
1054  *
1055  * @param mask Bits to mask from the requested/tested cpu type
1056  * @param req_cpu Requested cpu type
1057  * @param req_subcpu Requested cpu subtype
1058  * @param test_cpu Tested slice cpu type
1059  * @param test_subcpu Tested slice cpu subtype
1060  */
1061 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)1062 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
1063     cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
1064     cpu_subtype_t test_subcpu)
1065 {
1066 	if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
1067 		return FALSE;
1068 	}
1069 
1070 	test_subcpu &= ~CPU_SUBTYPE_MASK;
1071 	req_subcpu  &= ~CPU_SUBTYPE_MASK;
1072 
1073 	if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
1074 		return FALSE;
1075 	}
1076 
1077 	return TRUE;
1078 }
1079 
1080 
1081 #define MIN_IOS_TPRO_SDK_VERSION        0x00100000
1082 #define MIN_OSX_TPRO_SDK_VERSION        0x000D0000
1083 #define MIN_TVOS_TPRO_SDK_VERSION       0x000D0000
1084 #define MIN_WATCHOS_TPRO_SDK_VERSION    0x00090000
1085 #define MIN_DRIVERKIT_TPRO_SDK_VERSION  0x00600000
1086 
1087 static void
exec_setup_tpro(struct image_params * imgp,load_result_t * load_result)1088 exec_setup_tpro(struct image_params *imgp, load_result_t *load_result)
1089 {
1090 	extern boolean_t xprr_tpro_enabled;
1091 	extern boolean_t enable_user_modifiable_perms;
1092 	uint32_t min_sdk_version = 0;
1093 
1094 	/* x86-64 translated code cannot take advantage of TPRO */
1095 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1096 		return;
1097 	}
1098 
1099 	/* Do not enable on 32-bit VA targets */
1100 	if (!(imgp->ip_flags & IMGPF_IS_64BIT_ADDR)) {
1101 		return;
1102 	}
1103 
1104 	switch (load_result->ip_platform) {
1105 	case PLATFORM_IOS:
1106 	case PLATFORM_IOSSIMULATOR:
1107 	case PLATFORM_MACCATALYST:
1108 		min_sdk_version = MIN_IOS_TPRO_SDK_VERSION;
1109 		break;
1110 	case PLATFORM_MACOS:
1111 		min_sdk_version = MIN_OSX_TPRO_SDK_VERSION;
1112 		break;
1113 	case PLATFORM_TVOS:
1114 	case PLATFORM_TVOSSIMULATOR:
1115 		min_sdk_version = MIN_TVOS_TPRO_SDK_VERSION;
1116 		break;
1117 	case PLATFORM_WATCHOS:
1118 	case PLATFORM_WATCHOSSIMULATOR:
1119 		min_sdk_version = MIN_WATCHOS_TPRO_SDK_VERSION;
1120 		break;
1121 	case PLATFORM_DRIVERKIT:
1122 		min_sdk_version = MIN_DRIVERKIT_TPRO_SDK_VERSION;
1123 		break;
1124 	default:
1125 		/* TPRO is on by default for newer platforms */
1126 		break;
1127 	}
1128 
1129 }
1130 
1131 /*
1132  * If the passed in executable's vnode should use the RSR
1133  * shared region, then this should return TRUE, otherwise, return FALSE.
1134  */
1135 static uint32_t rsr_current_version = 0;
1136 boolean_t (*rsr_check_vnode)(void *vnode) = NULL;
1137 
1138 boolean_t
vnode_is_rsr(vnode_t vp)1139 vnode_is_rsr(vnode_t vp)
1140 {
1141 	if (!(vnode_isreg(vp) && vnode_tag(vp) == VT_APFS)) {
1142 		return FALSE;
1143 	}
1144 
1145 	if (rsr_check_vnode != NULL && rsr_check_vnode((void *)vp)) {
1146 		return TRUE;
1147 	}
1148 	return FALSE;
1149 }
1150 
1151 
1152 // Check entitlements to see if this is a hardened runtime binary.
1153 // Save this in load_result until later for two purposes:
1154 // 1. Once the task is created, we can mark it as hardened runtime if needed
1155 // 2. we can propagate which entitlements are present to the apple array
1156 static inline void
encode_HR_entitlement(const char * entitlement,HR_flags_t mask,const struct image_params * imgp,load_result_t * load_result)1157 encode_HR_entitlement(const char *entitlement, HR_flags_t mask,
1158     const struct image_params *imgp, load_result_t *load_result)
1159 {
1160 	if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
1161 		load_result->hardened_runtime_binary |= mask;
1162 	}
1163 }
1164 
1165 #if DEVELOPMENT || DEBUG
1166 /*
1167  * This function handles the case where the hardened-process entitlement
1168  * is set without a specific sub-feature entitlement, which is still under
1169  * adoption.
1170  *
1171  * For in-adoption features, the fallout of having certain
1172  * security sensitive components enabled but not qualified
1173  * is potentially too large. Therefore, we allow to have a
1174  * "forcing period" in which every binary entitled as
1175  * hardened-process is required to have an explicit setting
1176  * (true or false) for the security feature or otherwise
1177  * gets killed or at least traced at launch.
1178  *
1179  * return value: true if all policies restrictions met,
1180  *               false otherwise.
1181  */
1182 static inline bool
handle_missing_subfeature_entitlement(const struct image_params * imgp,const char * subfeature_entitlement)1183 handle_missing_subfeature_entitlement(
1184 	const struct image_params *imgp,
1185 	const char *subfeature_entitlement)
1186 {
1187 	switch (hardened_process_config) {
1188 	case HARDENED_PROCESS_CONFIG_SILENT:
1189 		break;
1190 	case HARDENED_PROCESS_CONFIG_LOG:
1191 		/*
1192 		 * Use the name directly from imgp since we haven't
1193 		 * set_proc_name() yet.
1194 		 */
1195 		printf("[WARNING] %s has hardened-process but not %s\n",
1196 		    imgp->ip_ndp->ni_cnd.cn_nameptr,
1197 		    subfeature_entitlement);
1198 		break;
1199 	case HARDENED_PROCESS_CONFIG_FATAL:
1200 		/*
1201 		 * When the policy defined as FATAL, we SIGKILL
1202 		 * the process.
1203 		 */
1204 		printf("[ERROR] %s has hardened-process but not %s\n",
1205 		    imgp->ip_ndp->ni_cnd.cn_nameptr,
1206 		    subfeature_entitlement);
1207 		return false;
1208 	default:
1209 		panic("invalid hardened-process policy");
1210 	}
1211 
1212 	return true;
1213 }
1214 #endif /* DEVELOPMENT || DEBUG */
1215 
1216 /*
1217  * Handle the hardened-process.hardened-heap entitlement.
1218  *
1219  * Note: hardened-heap is not inherited via spawn/exec;
1220  *       It is inherited (only) on fork, which is done
1221  *       via Apple strings.
1222  */
1223 static inline bool
apply_hardened_heap_policy(struct image_params * imgp,bool is_hardened_process)1224 apply_hardened_heap_policy(
1225 	struct image_params *imgp,
1226 	bool is_hardened_process)
1227 {
1228 	bool result = true;
1229 	bool set_hardened_heap = false;
1230 
1231 	bool hardened_heap_ent = false;
1232 	if (IOVnodeGetBooleanEntitlement(imgp->ip_vp,
1233 	    (int64_t)imgp->ip_arch_offset,
1234 	    SPAWN_ENABLE_HARDENED_HEAP,
1235 	    &hardened_heap_ent)) {
1236 		/*
1237 		 * The hardened-heap entitlement exists, use that
1238 		 * to decide about enablement.
1239 		 */
1240 		set_hardened_heap = hardened_heap_ent;
1241 	} else if (is_hardened_process) {
1242 #if DEVELOPMENT || DEBUG
1243 		/*
1244 		 * We should imply default from hardened-process. However,
1245 		 * bringup will take time and could be sensitive. We want
1246 		 * to allow teams to adopt incrementally.
1247 		 *
1248 		 * We will link hardened-heap to hardened-process when
1249 		 * adoption will be more stable.
1250 		 */
1251 		if (!handle_missing_subfeature_entitlement(imgp,
1252 		    SPAWN_ENABLE_HARDENED_HEAP)) {
1253 			result = false;
1254 		}
1255 #endif /* DEVELOPMENT || DEBUG */
1256 	}
1257 
1258 	if (set_hardened_heap) {
1259 		imgp->ip_flags |= IMGPF_HARDENED_HEAP;
1260 	}
1261 
1262 	return result;
1263 }
1264 
1265 
1266 /*
1267  * This function handles all the hardened-process related
1268  * mitigations, parse their entitlements, and apply policies.
1269  *
1270  * For feature-ready mitigations, having hardened-process=true
1271  * implies enablement. Sub-features specific entitlements can
1272  * override this, which means that even if we have hardened-process
1273  * exists and set to true, but a sub-feature entitlement exists
1274  * and set to false, we do not enable the sub-feature.
1275  *
1276  * return value: true if all policies restrictions met,
1277  *               false otherwise.
1278  */
1279 static bool
apply_hardened_process_policy(struct image_params * imgp,__unused proc_t proc,__unused bool is_platform_binary)1280 apply_hardened_process_policy(
1281 	struct image_params *imgp,
1282 	__unused proc_t proc,
1283 	__unused bool is_platform_binary)
1284 {
1285 	bool result = true;
1286 
1287 	/*
1288 	 * Check if the binary has hardened-process entitlement.
1289 	 */
1290 	bool is_hardened_process = false;
1291 	if (IOVnodeHasEntitlement(imgp->ip_vp,
1292 	    (int64_t)imgp->ip_arch_offset, SPAWN_ENABLE_HARDENED_PROCESS)) {
1293 		is_hardened_process = true;
1294 	}
1295 
1296 	if (!apply_hardened_heap_policy(imgp, is_hardened_process)) {
1297 		result = false;
1298 	}
1299 
1300 
1301 	return result;
1302 }
1303 
1304 uint32_t
rsr_get_version(void)1305 rsr_get_version(void)
1306 {
1307 	return os_atomic_load(&rsr_current_version, relaxed);
1308 }
1309 
1310 void
rsr_bump_version(void)1311 rsr_bump_version(void)
1312 {
1313 	os_atomic_inc(&rsr_current_version, relaxed);
1314 }
1315 
1316 #if XNU_TARGET_OS_OSX
1317 static int
1318 rsr_version_sysctl SYSCTL_HANDLER_ARGS
1319 {
1320 #pragma unused(arg1, arg2, oidp)
1321 	int value = rsr_get_version();
1322 	int error = SYSCTL_OUT(req, &value, sizeof(int));
1323 	if (error) {
1324 		return error;
1325 	}
1326 
1327 	if (!req->newptr) {
1328 		return 0;
1329 	}
1330 
1331 	error = SYSCTL_IN(req, &value, sizeof(int));
1332 	if (error) {
1333 		return error;
1334 	}
1335 	if (value != 0) {
1336 		rsr_bump_version();
1337 	}
1338 	return 0;
1339 }
1340 
1341 
1342 SYSCTL_PROC(_vm, OID_AUTO, shared_region_control,
1343     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
1344     0, 0, rsr_version_sysctl, "I", "");
1345 #endif /* XNU_TARGET_OS_OSX */
1346 
1347 /*
1348  * exec_mach_imgact
1349  *
1350  * Image activator for mach-o 1.0 binaries.
1351  *
1352  * Parameters;	struct image_params *	image parameter block
1353  *
1354  * Returns:	-1			not a fat binary (keep looking)
1355  *		-2			Success: encapsulated binary: reread
1356  *		>0			Failure: error number
1357  *		EBADARCH		Mach-o binary, but with an unrecognized
1358  *					architecture
1359  *		ENOMEM			No memory for child process after -
1360  *					can only happen after vfork()
1361  *
1362  * Important:	This image activator is NOT byte order neutral.
1363  *
1364  * Note:	A return value other than -1 indicates subsequent image
1365  *		activators should not be given the opportunity to attempt
1366  *		to activate the image.
1367  */
1368 static int
exec_mach_imgact(struct image_params * imgp)1369 exec_mach_imgact(struct image_params *imgp)
1370 {
1371 	struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1372 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
1373 	int                     error = 0;
1374 	task_t                  task;
1375 	task_t                  new_task = NULL; /* protected by vfexec */
1376 	thread_t                thread;
1377 	struct uthread          *uthread;
1378 	vm_map_switch_context_t switch_ctx;
1379 	vm_map_t old_map = VM_MAP_NULL;
1380 	vm_map_t map = VM_MAP_NULL;
1381 	load_return_t           lret;
1382 	load_result_t           load_result = {};
1383 	struct _posix_spawnattr *psa = NULL;
1384 	int                     spawn = (imgp->ip_flags & IMGPF_SPAWN);
1385 	const int               vfexec = 0;
1386 	int                     exec = (imgp->ip_flags & IMGPF_EXEC);
1387 	os_reason_t             exec_failure_reason = OS_REASON_NULL;
1388 	boolean_t               reslide = FALSE;
1389 	char *                  userspace_coredump_name = NULL;
1390 
1391 	/*
1392 	 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1393 	 * is a reserved field on the end, so for the most part, we can
1394 	 * treat them as if they were identical. Reverse-endian Mach-O
1395 	 * binaries are recognized but not compatible.
1396 	 */
1397 	if ((mach_header->magic == MH_CIGAM) ||
1398 	    (mach_header->magic == MH_CIGAM_64)) {
1399 		error = EBADARCH;
1400 		goto bad;
1401 	}
1402 
1403 	if ((mach_header->magic != MH_MAGIC) &&
1404 	    (mach_header->magic != MH_MAGIC_64)) {
1405 		error = -1;
1406 		goto bad;
1407 	}
1408 
1409 	if (mach_header->filetype != MH_EXECUTE) {
1410 		error = -1;
1411 		goto bad;
1412 	}
1413 
1414 	if (imgp->ip_origcputype != 0) {
1415 		/* Fat header previously had an idea about this thin file */
1416 		if (imgp->ip_origcputype != mach_header->cputype ||
1417 		    imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1418 			error = EBADARCH;
1419 			goto bad;
1420 		}
1421 	} else {
1422 		imgp->ip_origcputype = mach_header->cputype;
1423 		imgp->ip_origcpusubtype = mach_header->cpusubtype;
1424 	}
1425 
1426 	task = current_task();
1427 	thread = current_thread();
1428 	uthread = get_bsdthread_info(thread);
1429 
1430 	if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1431 		imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1432 	}
1433 
1434 
1435 	/* If posix_spawn binprefs exist, respect those prefs. */
1436 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1437 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
1438 		int pr = 0;
1439 		for (pr = 0; pr < NBINPREFS; pr++) {
1440 			cpu_type_t pref = psa->psa_binprefs[pr];
1441 			cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1442 
1443 			if (pref == 0) {
1444 				/* No suitable arch in the pref list */
1445 				error = EBADARCH;
1446 				goto bad;
1447 			}
1448 
1449 			if (pref == CPU_TYPE_ANY) {
1450 				/* Jump to regular grading */
1451 				goto grade;
1452 			}
1453 
1454 			if (binary_match(CPU_ARCH_MASK, pref, subpref,
1455 			    imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1456 				goto grade;
1457 			}
1458 		}
1459 		error = EBADARCH;
1460 		goto bad;
1461 	}
1462 grade:
1463 	if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1464 	    imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1465 		error = EBADARCH;
1466 		goto bad;
1467 	}
1468 
1469 	if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1470 	    imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1471 #if __x86_64__
1472 		const char *excpath;
1473 		error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1474 		os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1475 #endif
1476 		error = EBADARCH;
1477 		goto bad;
1478 	}
1479 
1480 #if defined(HAS_APPLE_PAC)
1481 	assert(mach_header->cputype == CPU_TYPE_ARM64
1482 	    );
1483 
1484 	if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1485 	    arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1486 	    ) {
1487 		imgp->ip_flags &= ~IMGPF_NOJOP;
1488 	} else {
1489 		imgp->ip_flags |= IMGPF_NOJOP;
1490 	}
1491 #endif
1492 
1493 	/* Copy in arguments/environment from the old process */
1494 	error = exec_extract_strings(imgp);
1495 	if (error) {
1496 		goto bad;
1497 	}
1498 
1499 	AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1500 	    imgp->ip_endargv - imgp->ip_startargv);
1501 	AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1502 	    imgp->ip_endenvv - imgp->ip_endargv);
1503 
1504 	/* reset local idea of thread, uthread, task */
1505 	thread = imgp->ip_new_thread;
1506 	uthread = get_bsdthread_info(thread);
1507 	task = new_task = get_threadtask(thread);
1508 
1509 	/*
1510 	 *	Load the Mach-O file.
1511 	 *
1512 	 * NOTE: An error after this point  indicates we have potentially
1513 	 * destroyed or overwritten some process state while attempting an
1514 	 * execve() following a vfork(), which is an unrecoverable condition.
1515 	 * We send the new process an immediate SIGKILL to avoid it executing
1516 	 * any instructions in the mutated address space. For true spawns,
1517 	 * this is not the case, and "too late" is still not too late to
1518 	 * return an error code to the parent process.
1519 	 */
1520 
1521 	/*
1522 	 * Actually load the image file we previously decided to load.
1523 	 */
1524 	lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1525 	if (lret != LOAD_SUCCESS) {
1526 		error = load_return_to_errno(lret);
1527 
1528 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1529 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1530 		if (lret == LOAD_BADMACHO_UPX) {
1531 			set_proc_name(imgp, p);
1532 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1533 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1534 		} else {
1535 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1536 
1537 			if (bootarg_execfailurereports) {
1538 				set_proc_name(imgp, p);
1539 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1540 			}
1541 		}
1542 
1543 		exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1544 
1545 		goto badtoolate;
1546 	}
1547 
1548 	assert(imgp->ip_free_map == NULL);
1549 
1550 
1551 	// It's safe to check entitlements anytime after `load_machfile` if you check
1552 	// based on the vnode in imgp. We must perform this entitlement check
1553 	// before we start using load_result->hardened_runtime_binary further down
1554 	load_result.hardened_runtime_binary = 0;
1555 	encode_HR_entitlement(kCSWebBrowserHostEntitlement, BrowserHostEntitlementMask, imgp, &load_result);
1556 	encode_HR_entitlement(kCSWebBrowserGPUEntitlement, BrowserGPUEntitlementMask, imgp, &load_result);
1557 	encode_HR_entitlement(kCSWebBrowserNetworkEntitlement, BrowserNetworkEntitlementMask, imgp, &load_result);
1558 	encode_HR_entitlement(kCSWebBrowserWebContentEntitlement, BrowserWebContentEntitlementMask, imgp, &load_result);
1559 
1560 	/*
1561 	 * ERROR RECOVERY
1562 	 *
1563 	 * load_machfile() returned the new VM map ("map") but we haven't
1564 	 * committed to it yet.
1565 	 * Any error path between here and the point where we commit to using
1566 	 * the new "map" (with swap_task_map()) should deallocate "map".
1567 	 */
1568 
1569 #ifndef KASAN
1570 	/*
1571 	 * Security: zone sanity checks on fresh boot or initproc re-exec.
1572 	 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1573 	 * which means here is the earliest point we can assert on empty service port label zone,
1574 	 * after load_machfile() above terminates old launchd's IPC space.
1575 	 *
1576 	 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1577 	 * under quarantine.
1578 	 */
1579 	if (task_pid(task) == 1) {
1580 		zone_userspace_reboot_checks();
1581 	}
1582 #endif
1583 
1584 	proc_lock(p);
1585 	p->p_cputype = imgp->ip_origcputype;
1586 	p->p_cpusubtype = imgp->ip_origcpusubtype;
1587 	proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1588 	exec_setup_tpro(imgp, &load_result);
1589 
1590 	vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1591 	vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1592 	vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1593 
1594 #if XNU_TARGET_OS_OSX
1595 	if (proc_platform(p) == PLATFORM_IOS) {
1596 		assert(vm_map_is_alien(map));
1597 	} else {
1598 		assert(!vm_map_is_alien(map));
1599 	}
1600 #endif /* XNU_TARGET_OS_OSX */
1601 	proc_unlock(p);
1602 
1603 	/*
1604 	 * Handle hardened-process mitigations, parse entitlements
1605 	 * and apply enablements.
1606 	 */
1607 	if (!apply_hardened_process_policy(imgp, p, load_result.platform_binary)) {
1608 #if DEVELOPMENT || DEBUG
1609 		set_proc_name(imgp, p);
1610 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1611 		if (bootarg_execfailurereports) {
1612 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1613 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1614 		}
1615 		/* release new address space since we won't use it */
1616 		imgp->ip_free_map = map;
1617 		map = VM_MAP_NULL;
1618 		goto badtoolate;
1619 #endif /* DEVELOPMENT || DEBUG */
1620 	}
1621 
1622 	/*
1623 	 * Set TPRO flags if enabled
1624 	 */
1625 
1626 	/*
1627 	 * Set code-signing flags if this binary is signed, or if parent has
1628 	 * requested them on exec.
1629 	 */
1630 	if (load_result.csflags & CS_VALID) {
1631 		imgp->ip_csflags |= load_result.csflags &
1632 		    (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1633 		    CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1634 		    CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1635 		    CS_ENTITLEMENT_FLAGS |
1636 		    CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1637 	} else {
1638 		imgp->ip_csflags &= ~CS_VALID;
1639 	}
1640 
1641 	if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1642 		imgp->ip_csflags |= CS_HARD;
1643 	}
1644 	if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1645 		imgp->ip_csflags |= CS_KILL;
1646 	}
1647 	if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1648 		imgp->ip_csflags |= CS_ENFORCEMENT;
1649 	}
1650 	if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1651 		if (proc_getcsflags(p) & CS_INSTALLER) {
1652 			imgp->ip_csflags |= CS_INSTALLER;
1653 		}
1654 		if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1655 			imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1656 		}
1657 		if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1658 			imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1659 		}
1660 	}
1661 
1662 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1663 	/*
1664 	 * ptrauth version 0 is a preview ABI.  Developers can opt into running
1665 	 * their own arm64e binaries for local testing, with the understanding
1666 	 * that future OSes may break ABI.
1667 	 */
1668 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1669 	    CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1670 	    !load_result.platform_binary &&
1671 	    !bootarg_arm64e_preview_abi) {
1672 		static bool logged_once = false;
1673 		set_proc_name(imgp, p);
1674 
1675 		printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1676 		if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1677 			printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1678 		}
1679 
1680 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1681 		if (bootarg_execfailurereports) {
1682 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1683 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1684 		}
1685 
1686 		/* release new address space since we won't use it */
1687 		imgp->ip_free_map = map;
1688 		map = VM_MAP_NULL;
1689 		goto badtoolate;
1690 	}
1691 
1692 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1693 	    imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1694 	    load_result.platform_binary &&
1695 	    (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1696 		set_proc_name(imgp, p);
1697 		printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
1698 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1699 		if (bootarg_execfailurereports) {
1700 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1701 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1702 		}
1703 
1704 		/* release new address space since we won't use it */
1705 		imgp->ip_free_map = map;
1706 		map = VM_MAP_NULL;
1707 		goto badtoolate;
1708 	}
1709 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1710 
1711 
1712 
1713 	/*
1714 	 * Set up the shared cache region in the new process.
1715 	 *
1716 	 * Normally there is a single shared region per architecture.
1717 	 * However on systems with Pointer Authentication, we can create
1718 	 * multiple shared caches with the amount of sharing determined
1719 	 * by team-id or entitlement. Inherited shared region IDs are used
1720 	 * for system processes that need to match and be able to inspect
1721 	 * a pre-existing task.
1722 	 */
1723 	int cpu_subtype = 0; /* all cpu_subtypes use the same shared region */
1724 #if __has_feature(ptrauth_calls)
1725 	char *shared_region_id = NULL;
1726 	size_t len;
1727 	char *base;
1728 	const char *cbase;
1729 #define HARDENED_RUNTIME_CONTENT_ID "C-"
1730 #define TEAM_ID_PREFIX "T-"
1731 #define ENTITLE_PREFIX "E-"
1732 #define SR_PREFIX_LEN  2
1733 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1734 
1735 	if (cpu_type() == CPU_TYPE_ARM64 &&
1736 	    arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1737 	    (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1738 		assertf(p->p_cputype == CPU_TYPE_ARM64,
1739 		    "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1740 		    p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1741 
1742 		/*
1743 		 * arm64e uses pointer authentication, so request a separate
1744 		 * shared region for this CPU subtype.
1745 		 */
1746 		cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1747 
1748 		/*
1749 		 * Determine which shared cache to select based on being told,
1750 		 * matching a team-id or matching an entitlement.
1751 		 */
1752 		if (load_result.hardened_runtime_binary & BrowserWebContentEntitlementMask) {
1753 			len = sizeof(HARDENED_RUNTIME_CONTENT_ID);
1754 			shared_region_id = kalloc_data(len, Z_WAITOK | Z_NOFAIL);
1755 			strlcpy(shared_region_id, HARDENED_RUNTIME_CONTENT_ID, len);
1756 		} else if (imgp->ip_inherited_shared_region_id) {
1757 			len = strlen(imgp->ip_inherited_shared_region_id);
1758 			shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1759 			memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1760 		} else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1761 			len = strlen(cbase);
1762 			if (vm_shared_region_per_team_id) {
1763 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1764 				    Z_WAITOK | Z_NOFAIL);
1765 				memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1766 				memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1767 			}
1768 		} else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1769 		    (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1770 			len = strlen(base);
1771 			if (vm_shared_region_by_entitlement) {
1772 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1773 				    Z_WAITOK | Z_NOFAIL);
1774 				memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1775 				memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1776 			}
1777 			/* Discard the copy of the entitlement */
1778 			kfree_data(base, len + 1);
1779 		}
1780 	}
1781 
1782 	if (imgp->ip_flags & IMGPF_RESLIDE) {
1783 		reslide = TRUE;
1784 	}
1785 
1786 	/* use "" as the default shared_region_id */
1787 	if (shared_region_id == NULL) {
1788 		shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1789 	}
1790 
1791 	/* ensure there's a unique pointer signing key for this shared_region_id */
1792 	shared_region_key_alloc(shared_region_id,
1793 	    imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1794 	task_set_shared_region_id(task, shared_region_id);
1795 	shared_region_id = NULL;
1796 #endif /* __has_feature(ptrauth_calls) */
1797 
1798 #if CONFIG_ROSETTA
1799 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1800 		OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
1801 	} else if (p->p_flag & P_TRANSLATED) {
1802 		OSBitAndAtomic(~P_TRANSLATED, &p->p_flag);
1803 	}
1804 #endif
1805 
1806 	int cputype = cpu_type();
1807 
1808 	uint32_t rsr_version = 0;
1809 #if XNU_TARGET_OS_OSX
1810 	if (vnode_is_rsr(imgp->ip_vp)) {
1811 		rsr_version = rsr_get_version();
1812 		os_atomic_or(&p->p_ladvflag, P_RSR, relaxed);
1813 		os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_ALTLINK, relaxed);
1814 	}
1815 #endif /* XNU_TARGET_OS_OSX */
1816 
1817 	error = vm_map_exec(map, task, load_result.is_64bit_addr,
1818 	    (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide,
1819 	    (imgp->ip_flags & IMGPF_DRIVER) != 0,
1820 	    rsr_version);
1821 
1822 	if (error) {
1823 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1824 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAP_EXEC_FAILURE, 0, 0);
1825 
1826 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAP_EXEC_FAILURE);
1827 		if (bootarg_execfailurereports) {
1828 			set_proc_name(imgp, p);
1829 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1830 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1831 		}
1832 		/* release new address space since we won't use it */
1833 		imgp->ip_free_map = map;
1834 		map = VM_MAP_NULL;
1835 		goto badtoolate;
1836 	}
1837 
1838 	/*
1839 	 * Close file descriptors which specify close-on-exec.
1840 	 */
1841 	fdt_exec(p, vfs_context_ucred(imgp->ip_vfs_context),
1842 	    psa != NULL ? psa->psa_flags : 0, imgp->ip_new_thread, exec);
1843 
1844 	/*
1845 	 * deal with set[ug]id.
1846 	 */
1847 	error = exec_handle_sugid(imgp);
1848 	if (error) {
1849 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1850 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1851 
1852 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1853 		if (bootarg_execfailurereports) {
1854 			set_proc_name(imgp, p);
1855 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1856 		}
1857 
1858 		/* release new address space since we won't use it */
1859 		imgp->ip_free_map = map;
1860 		map = VM_MAP_NULL;
1861 		goto badtoolate;
1862 	}
1863 
1864 	/*
1865 	 * Commit to new map.
1866 	 *
1867 	 * Swap the new map for the old for target task, which consumes
1868 	 * our new map reference but each leaves us responsible for the
1869 	 * old_map reference.  That lets us get off the pmap associated
1870 	 * with it, and then we can release it.
1871 	 *
1872 	 * The map needs to be set on the target task which is different
1873 	 * than current task, thus swap_task_map is used instead of
1874 	 * vm_map_switch.
1875 	 */
1876 	old_map = swap_task_map(task, thread, map);
1877 #if MACH_ASSERT
1878 	/*
1879 	 * Reset the pmap's process info to prevent ledger checks
1880 	 * which might fail due to the ledgers being shared between
1881 	 * the old and new pmaps.
1882 	 */
1883 	vm_map_pmap_set_process(old_map, -1, "<old_map>");
1884 #endif /* MACH_ASSERT */
1885 	imgp->ip_free_map = old_map;
1886 	old_map = NULL;
1887 
1888 	lret = activate_exec_state(task, p, thread, &load_result);
1889 	if (lret != KERN_SUCCESS) {
1890 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1891 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1892 
1893 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1894 		if (bootarg_execfailurereports) {
1895 			set_proc_name(imgp, p);
1896 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1897 		}
1898 
1899 		goto badtoolate;
1900 	}
1901 
1902 	/*
1903 	 * deal with voucher on exec-calling thread.
1904 	 */
1905 	if (imgp->ip_new_thread == NULL) {
1906 		thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1907 	}
1908 
1909 	/* Make sure we won't interrupt ourself signalling a partial process */
1910 	if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1911 		psignal(p, SIGTRAP);
1912 	}
1913 
1914 	if (load_result.unixproc &&
1915 	    create_unix_stack(get_task_map(task),
1916 	    &load_result,
1917 	    p) != KERN_SUCCESS) {
1918 		error = load_return_to_errno(LOAD_NOSPACE);
1919 
1920 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1921 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1922 
1923 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1924 		if (bootarg_execfailurereports) {
1925 			set_proc_name(imgp, p);
1926 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1927 		}
1928 
1929 		goto badtoolate;
1930 	}
1931 
1932 	if (load_result.hardened_runtime_binary) {
1933 		if (cs_debug) {
1934 			printf("setting hardened runtime with entitlement mask= "
1935 			    "0x%x on task: pid = %d\n",
1936 			    load_result.hardened_runtime_binary,
1937 			    proc_getpid(p));
1938 		}
1939 		task_set_hardened_runtime(task, true);
1940 	}
1941 
1942 	/*
1943 	 * The load result will have already been munged by AMFI to include the
1944 	 * platform binary flag if boot-args dictated it (AMFI will mark anything
1945 	 * that doesn't go through the upcall path as a platform binary if its
1946 	 * enforcement is disabled).
1947 	 */
1948 	if (load_result.platform_binary) {
1949 		if (cs_debug) {
1950 			printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1951 		}
1952 
1953 		/*
1954 		 * We must use 'task' here because the proc's task has not yet been
1955 		 * switched to the new one.
1956 		 */
1957 		task_set_platform_binary(task, TRUE);
1958 	} else {
1959 		if (cs_debug) {
1960 			printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1961 		}
1962 
1963 		task_set_platform_binary(task, FALSE);
1964 	}
1965 
1966 #if XNU_TARGET_OS_OSX
1967 	/* Disable mach hardening for all 1P tasks which load 3P plugins */
1968 	if (imgp->ip_flags & IMGPF_3P_PLUGINS) {
1969 		if (cs_debug) {
1970 			printf("Disabling some mach hardening on task due to 3P plugins: pid = %d\n", proc_getpid(p));
1971 		}
1972 		task_disable_mach_hardening(task);
1973 	}
1974 #if DEVELOPMENT || DEBUG
1975 	/* Disable mach hardening for all tasks if amfi_get_out_of_my_way is set.
1976 	 * Customers will have to turn SIP off to use this boot-arg, and so this is
1977 	 * only needed internally since we disable this feature when SIP is off. */
1978 	if (AMFI_bootarg_disable_mach_hardening) {
1979 		if (cs_debug) {
1980 			printf("Disabling some mach hardening on task due to AMFI boot-args: pid = %d\n", proc_getpid(p));
1981 		}
1982 		task_disable_mach_hardening(task);
1983 	}
1984 #endif /* DEVELOPMENT || DEBUG */
1985 #endif /* XNU_TARGET_OS_OSX */
1986 
1987 	/*
1988 	 * Set starting EXC_GUARD and control port behavior for task now that
1989 	 * platform and hardened runtime is set. Use the name directly from imgp since we haven't
1990 	 * set_proc_name() yet. Also make control port for the task and main thread
1991 	 * immovable/pinned based on task's option.
1992 	 *
1993 	 * Must happen before main thread port copyout in exc_add_apple_strings.
1994 	 */
1995 	task_set_exc_guard_ctrl_port_default(task, thread,
1996 	    imgp->ip_ndp->ni_cnd.cn_nameptr,
1997 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1998 	    proc_is_simulated(p),
1999 	    load_result.ip_platform,
2000 	    load_result.lr_sdk);
2001 
2002 	error = exec_add_apple_strings(imgp, &load_result); /* copies out main thread port */
2003 
2004 	if (error) {
2005 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2006 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
2007 
2008 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
2009 		if (bootarg_execfailurereports) {
2010 			set_proc_name(imgp, p);
2011 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2012 		}
2013 		goto badtoolate;
2014 	}
2015 
2016 	/* Switch to target task's map to copy out strings */
2017 	switch_ctx = vm_map_switch_to(get_task_map(task));
2018 
2019 	if (load_result.unixproc) {
2020 		user_addr_t     ap;
2021 
2022 		/*
2023 		 * Copy the strings area out into the new process address
2024 		 * space.
2025 		 */
2026 		ap = p->user_stack;
2027 		error = exec_copyout_strings(imgp, &ap);
2028 		if (error) {
2029 			vm_map_switch_back(switch_ctx);
2030 
2031 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2032 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
2033 
2034 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
2035 			if (bootarg_execfailurereports) {
2036 				set_proc_name(imgp, p);
2037 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2038 			}
2039 			goto badtoolate;
2040 		}
2041 		/* Set the stack */
2042 		thread_setuserstack(thread, ap);
2043 	}
2044 
2045 	if (load_result.dynlinker || load_result.is_rosetta) {
2046 		user_addr_t        ap;
2047 		int                     new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
2048 
2049 		/* Adjust the stack */
2050 		ap = thread_adjuserstack(thread, -new_ptr_size);
2051 		error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
2052 
2053 		if (error) {
2054 			vm_map_switch_back(switch_ctx);
2055 
2056 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2057 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
2058 
2059 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
2060 			if (bootarg_execfailurereports) {
2061 				set_proc_name(imgp, p);
2062 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2063 			}
2064 			goto badtoolate;
2065 		}
2066 		error = task_set_dyld_info(task, load_result.all_image_info_addr,
2067 		    load_result.all_image_info_size, false);
2068 		if (error) {
2069 			vm_map_switch_back(switch_ctx);
2070 
2071 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2072 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
2073 
2074 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
2075 			if (bootarg_execfailurereports) {
2076 				set_proc_name(imgp, p);
2077 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2078 			}
2079 			error = EINVAL;
2080 			goto badtoolate;
2081 		}
2082 	} else {
2083 		/*
2084 		 * No dyld or rosetta loaded, set the TF_DYLD_ALL_IMAGE_FINAL bit on task.
2085 		 */
2086 		error = task_set_dyld_info(task, MACH_VM_MIN_ADDRESS,
2087 		    0, true);
2088 		if (error) {
2089 			vm_map_switch_back(switch_ctx);
2090 
2091 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2092 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
2093 
2094 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
2095 			if (bootarg_execfailurereports) {
2096 				set_proc_name(imgp, p);
2097 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2098 			}
2099 			error = EINVAL;
2100 			goto badtoolate;
2101 		}
2102 	}
2103 
2104 #if CONFIG_ROSETTA
2105 	if (load_result.is_rosetta) {
2106 		// Add an fd for the executable file for Rosetta's use
2107 		int main_binary_fd;
2108 		struct fileproc *fp;
2109 
2110 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &main_binary_fd);
2111 		if (error) {
2112 			vm_map_switch_back(switch_ctx);
2113 
2114 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2115 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
2116 
2117 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
2118 			if (bootarg_execfailurereports) {
2119 				set_proc_name(imgp, p);
2120 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2121 			}
2122 			goto badtoolate;
2123 		}
2124 
2125 		error = VNOP_OPEN(imgp->ip_vp, FREAD, imgp->ip_vfs_context);
2126 		if (error) {
2127 			vm_map_switch_back(switch_ctx);
2128 
2129 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2130 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
2131 
2132 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
2133 			if (bootarg_execfailurereports) {
2134 				set_proc_name(imgp, p);
2135 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2136 			}
2137 			goto cleanup_rosetta_fp;
2138 		}
2139 
2140 		fp->fp_glob->fg_flag = FREAD;
2141 		fp->fp_glob->fg_ops = &vnops;
2142 		fp_set_data(fp, imgp->ip_vp);
2143 
2144 		proc_fdlock(p);
2145 		procfdtbl_releasefd(p, main_binary_fd, NULL);
2146 		fp_drop(p, main_binary_fd, fp, 1);
2147 		proc_fdunlock(p);
2148 
2149 		vnode_ref(imgp->ip_vp);
2150 
2151 		// Pass the dyld load address, main binary fd, and dyld fd on the stack
2152 		uint64_t ap = thread_adjuserstack(thread, -24);
2153 
2154 		error = copyoutptr((user_addr_t)load_result.dynlinker_fd, ap, 8);
2155 		if (error) {
2156 			vm_map_switch_back(switch_ctx);
2157 
2158 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2159 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
2160 
2161 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
2162 			if (bootarg_execfailurereports) {
2163 				set_proc_name(imgp, p);
2164 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2165 			}
2166 			goto cleanup_rosetta_fp;
2167 		}
2168 
2169 		error = copyoutptr(load_result.dynlinker_mach_header, ap + 8, 8);
2170 		if (error) {
2171 			vm_map_switch_back(switch_ctx);
2172 
2173 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2174 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
2175 
2176 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
2177 			if (bootarg_execfailurereports) {
2178 				set_proc_name(imgp, p);
2179 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2180 			}
2181 			goto cleanup_rosetta_fp;
2182 		}
2183 
2184 		error = copyoutptr((user_addr_t)main_binary_fd, ap + 16, 8);
2185 		if (error) {
2186 			vm_map_switch_back(switch_ctx);
2187 
2188 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
2189 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
2190 
2191 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
2192 			if (bootarg_execfailurereports) {
2193 				set_proc_name(imgp, p);
2194 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
2195 			}
2196 			goto cleanup_rosetta_fp;
2197 		}
2198 
2199 cleanup_rosetta_fp:
2200 		if (error) {
2201 			fp_free(p, load_result.dynlinker_fd, load_result.dynlinker_fp);
2202 			fp_free(p, main_binary_fd, fp);
2203 			goto badtoolate;
2204 		}
2205 	}
2206 
2207 #endif
2208 
2209 	/* Avoid immediate VM faults back into kernel */
2210 	exec_prefault_data(p, imgp, &load_result);
2211 
2212 	vm_map_switch_back(switch_ctx);
2213 
2214 	/*
2215 	 * Reset signal state.
2216 	 */
2217 	execsigs(p, thread);
2218 
2219 	/*
2220 	 * need to cancel async IO requests that can be cancelled and wait for those
2221 	 * already active.  MAY BLOCK!
2222 	 */
2223 	_aio_exec( p );
2224 
2225 #if SYSV_SHM
2226 	/* FIXME: Till vmspace inherit is fixed: */
2227 	if (!vfexec && p->vm_shm) {
2228 		shmexec(p);
2229 	}
2230 #endif
2231 #if SYSV_SEM
2232 	/* Clean up the semaphores */
2233 	semexit(p);
2234 #endif
2235 
2236 	/*
2237 	 * Remember file name for accounting.
2238 	 */
2239 	p->p_acflag &= ~AFORK;
2240 
2241 	set_proc_name(imgp, p);
2242 
2243 #if CONFIG_SECLUDED_MEMORY
2244 	if (secluded_for_apps &&
2245 	    load_result.platform_binary) {
2246 		if (strncmp(p->p_name,
2247 		    "Camera",
2248 		    sizeof(p->p_name)) == 0) {
2249 			task_set_could_use_secluded_mem(task, TRUE);
2250 		} else {
2251 			task_set_could_use_secluded_mem(task, FALSE);
2252 		}
2253 		if (strncmp(p->p_name,
2254 		    "mediaserverd",
2255 		    sizeof(p->p_name)) == 0) {
2256 			task_set_could_also_use_secluded_mem(task, TRUE);
2257 		}
2258 		if (strncmp(p->p_name,
2259 		    "cameracaptured",
2260 		    sizeof(p->p_name)) == 0) {
2261 			task_set_could_also_use_secluded_mem(task, TRUE);
2262 		}
2263 	}
2264 #endif /* CONFIG_SECLUDED_MEMORY */
2265 
2266 #if __arm64__
2267 	if (load_result.legacy_footprint) {
2268 		task_set_legacy_footprint(task);
2269 	}
2270 #endif /* __arm64__ */
2271 
2272 	pal_dbg_set_task_name(task);
2273 
2274 #if DEVELOPMENT || DEBUG
2275 	/*
2276 	 * Update the pid an proc name for importance base if any
2277 	 */
2278 	task_importance_update_owner_info(task);
2279 #endif
2280 
2281 	proc_setexecutableuuid(p, &load_result.uuid[0]);
2282 
2283 #if CONFIG_DTRACE
2284 	dtrace_proc_exec(p);
2285 #endif
2286 
2287 
2288 	if (kdebug_enable) {
2289 		long args[4] = {};
2290 
2291 		uintptr_t fsid = 0, fileid = 0;
2292 		if (imgp->ip_vattr) {
2293 			uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
2294 			fsid   = (uintptr_t)fsid64;
2295 			fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
2296 			// check for (unexpected) overflow and trace zero in that case
2297 			if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
2298 				fsid = fileid = 0;
2299 			}
2300 		}
2301 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
2302 		    (uintptr_t)thread_tid(thread));
2303 
2304 		extern void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
2305 		kdebug_proc_name_args(p, args);
2306 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
2307 		    args[2], args[3], (uintptr_t)thread_tid(thread));
2308 	}
2309 
2310 
2311 	/*
2312 	 * If posix_spawned with the START_SUSPENDED flag, stop the
2313 	 * process before it runs.
2314 	 */
2315 	if (imgp->ip_px_sa != NULL) {
2316 		psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
2317 		if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
2318 			proc_lock(p);
2319 			p->p_stat = SSTOP;
2320 			proc_unlock(p);
2321 			(void) task_suspend_internal(task);
2322 		}
2323 	}
2324 
2325 	/*
2326 	 * mark as execed
2327 	 */
2328 	OSBitOrAtomic(P_EXEC, &p->p_flag);
2329 	proc_resetregister(p);
2330 	if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
2331 		proc_lock(p);
2332 		p->p_lflag &= ~P_LPPWAIT;
2333 		proc_unlock(p);
2334 		wakeup((caddr_t)p->p_pptr);
2335 	}
2336 
2337 	/*
2338 	 * Set up dext coredumps on kernel panic.
2339 	 * This requires the following:
2340 	 * - dext_panic_coredump=1 boot-arg (enabled by default on DEVELOPMENT, DEBUG and certain Seed builds)
2341 	 * - process must be a driver
2342 	 * - process must have the com.apple.private.enable-coredump-on-panic entitlement, and the
2343 	 *   entitlement has a string value.
2344 	 * - process must have the com.apple.private.enable-coredump-on-panic-seed-privacy-approved
2345 	 *   entitlement (Seed builds only).
2346 	 *
2347 	 * The core dump file name is formatted with the entitlement string value, followed by a hyphen
2348 	 * and the process PID.
2349 	 */
2350 	if (enable_dext_coredumps_on_panic &&
2351 	    (imgp->ip_flags & IMGPF_DRIVER) != 0 &&
2352 	    (userspace_coredump_name = IOVnodeGetEntitlement(imgp->ip_vp,
2353 	    (int64_t)imgp->ip_arch_offset, USERSPACE_COREDUMP_PANIC_ENTITLEMENT)) != NULL) {
2354 		size_t userspace_coredump_name_len = strlen(userspace_coredump_name);
2355 
2356 		char core_name[MACH_CORE_FILEHEADER_NAMELEN];
2357 		/* 16 - NULL char - strlen("-") - maximum of 5 digits for pid */
2358 		snprintf(core_name, MACH_CORE_FILEHEADER_NAMELEN, "%.9s-%d", userspace_coredump_name, proc_getpid(p));
2359 
2360 		kern_register_userspace_coredump(task, core_name);
2361 
2362 		/* Discard the copy of the entitlement */
2363 		kfree_data(userspace_coredump_name, userspace_coredump_name_len + 1);
2364 		userspace_coredump_name = NULL;
2365 	}
2366 
2367 	goto done;
2368 
2369 badtoolate:
2370 	/* Don't allow child process to execute any instructions */
2371 	if (!spawn) {
2372 		{
2373 			assert(exec_failure_reason != OS_REASON_NULL);
2374 			if (bootarg_execfailurereports) {
2375 				set_proc_name(imgp, current_proc());
2376 			}
2377 			psignal_with_reason(current_proc(), SIGKILL, exec_failure_reason);
2378 			exec_failure_reason = OS_REASON_NULL;
2379 
2380 			if (exec) {
2381 				/* Terminate the exec copy task */
2382 				task_terminate_internal(task);
2383 			}
2384 		}
2385 
2386 		/* We can't stop this system call at this point, so just pretend we succeeded */
2387 		error = 0;
2388 	} else {
2389 		os_reason_free(exec_failure_reason);
2390 		exec_failure_reason = OS_REASON_NULL;
2391 	}
2392 
2393 done:
2394 	if (load_result.threadstate) {
2395 		kfree_data(load_result.threadstate, load_result.threadstate_sz);
2396 		load_result.threadstate = NULL;
2397 	}
2398 
2399 bad:
2400 	/* If we hit this, we likely would have leaked an exit reason */
2401 	assert(exec_failure_reason == OS_REASON_NULL);
2402 	return error;
2403 }
2404 
2405 
2406 
2407 
2408 /*
2409  * Our image activator table; this is the table of the image types we are
2410  * capable of loading.  We list them in order of preference to ensure the
2411  * fastest image load speed.
2412  *
2413  * XXX hardcoded, for now; should use linker sets
2414  */
2415 struct execsw {
2416 	int(*const ex_imgact)(struct image_params *);
2417 	const char *ex_name;
2418 }const execsw[] = {
2419 	{ exec_mach_imgact, "Mach-o Binary" },
2420 	{ exec_fat_imgact, "Fat Binary" },
2421 	{ exec_shell_imgact, "Interpreter Script" },
2422 	{ NULL, NULL}
2423 };
2424 
2425 
2426 /*
2427  * exec_activate_image
2428  *
2429  * Description:	Iterate through the available image activators, and activate
2430  *		the image associated with the imgp structure.  We start with
2431  *		the activator for Mach-o binaries followed by that for Fat binaries
2432  *		for Interpreter scripts.
2433  *
2434  * Parameters:	struct image_params *	Image parameter block
2435  *
2436  * Returns:	0			Success
2437  *		ENOEXEC			No activator for image.
2438  *		EBADEXEC		The executable is corrupt/unknown
2439  *	execargs_alloc:EINVAL		Invalid argument
2440  *	execargs_alloc:EACCES		Permission denied
2441  *	execargs_alloc:EINTR		Interrupted function
2442  *	execargs_alloc:ENOMEM		Not enough space
2443  *	exec_save_path:EFAULT		Bad address
2444  *	exec_save_path:ENAMETOOLONG	Filename too long
2445  *	exec_check_permissions:EACCES	Permission denied
2446  *	exec_check_permissions:ENOEXEC	Executable file format error
2447  *	exec_check_permissions:ETXTBSY	Text file busy [misuse of error code]
2448  *	exec_check_permissions:???
2449  *	namei:???
2450  *	vn_rdwr:???			[anything vn_rdwr can return]
2451  *	<ex_imgact>:???			[anything an imgact can return]
2452  *	EDEADLK				Process is being terminated
2453  */
2454 static int
exec_activate_image(struct image_params * imgp)2455 exec_activate_image(struct image_params *imgp)
2456 {
2457 	struct nameidata *ndp = NULL;
2458 	const char *excpath;
2459 	int error;
2460 	int resid;
2461 	int once = 1;   /* save SGUID-ness for interpreted files */
2462 	int i;
2463 	int itercount = 0;
2464 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2465 
2466 	/*
2467 	 * For exec, the translock needs to be taken on old proc and not
2468 	 * on new shadow proc.
2469 	 */
2470 	if (imgp->ip_flags & IMGPF_EXEC) {
2471 		p = current_proc();
2472 	}
2473 
2474 	error = execargs_alloc(imgp);
2475 	if (error) {
2476 		goto bad_notrans;
2477 	}
2478 
2479 	error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
2480 	if (error) {
2481 		goto bad_notrans;
2482 	}
2483 
2484 	/* Use excpath, which contains the copyin-ed exec path */
2485 	DTRACE_PROC1(exec, uintptr_t, excpath);
2486 
2487 	ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2488 
2489 	NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
2490 	    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2491 
2492 again:
2493 	error = namei(ndp);
2494 	if (error) {
2495 		if (error == ERESTART) {
2496 			error = EINTR;
2497 		}
2498 		goto bad_notrans;
2499 	}
2500 	imgp->ip_ndp = ndp;     /* successful namei(); call nameidone() later */
2501 	imgp->ip_vp = ndp->ni_vp;       /* if set, need to vnode_put() at some point */
2502 
2503 	/*
2504 	 * Before we start the transition from binary A to binary B, make
2505 	 * sure another thread hasn't started exiting the process.  We grab
2506 	 * the proc lock to check p_lflag initially, and the transition
2507 	 * mechanism ensures that the value doesn't change after we release
2508 	 * the lock.
2509 	 */
2510 	proc_lock(p);
2511 	if (p->p_lflag & P_LEXIT) {
2512 		error = EDEADLK;
2513 		proc_unlock(p);
2514 		goto bad_notrans;
2515 	}
2516 	error = proc_transstart(p, 1, 0);
2517 	proc_unlock(p);
2518 	if (error) {
2519 		goto bad_notrans;
2520 	}
2521 
2522 	error = exec_check_permissions(imgp);
2523 	if (error) {
2524 		goto bad;
2525 	}
2526 
2527 	/* Copy; avoid invocation of an interpreter overwriting the original */
2528 	if (once) {
2529 		once = 0;
2530 		*imgp->ip_origvattr = *imgp->ip_vattr;
2531 	}
2532 
2533 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
2534 	    UIO_SYSSPACE, IO_NODELOCKED,
2535 	    vfs_context_ucred(imgp->ip_vfs_context),
2536 	    &resid, vfs_context_proc(imgp->ip_vfs_context));
2537 	if (error) {
2538 		goto bad;
2539 	}
2540 
2541 	if (resid) {
2542 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
2543 	}
2544 
2545 encapsulated_binary:
2546 	/* Limit the number of iterations we will attempt on each binary */
2547 	if (++itercount > EAI_ITERLIMIT) {
2548 		error = EBADEXEC;
2549 		goto bad;
2550 	}
2551 	error = -1;
2552 	for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
2553 		error = (*execsw[i].ex_imgact)(imgp);
2554 
2555 		switch (error) {
2556 		/* case -1: not claimed: continue */
2557 		case -2:                /* Encapsulated binary, imgp->ip_XXX set for next iteration */
2558 			goto encapsulated_binary;
2559 
2560 		case -3:                /* Interpreter */
2561 #if CONFIG_MACF
2562 			/*
2563 			 * Copy the script label for later use. Note that
2564 			 * the label can be different when the script is
2565 			 * actually read by the interpreter.
2566 			 */
2567 			if (imgp->ip_scriptlabelp) {
2568 				mac_vnode_label_free(imgp->ip_scriptlabelp);
2569 				imgp->ip_scriptlabelp = NULL;
2570 			}
2571 			imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
2572 			if (imgp->ip_scriptlabelp == NULL) {
2573 				error = ENOMEM;
2574 				break;
2575 			}
2576 			mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
2577 			    imgp->ip_scriptlabelp);
2578 
2579 			/*
2580 			 * Take a ref of the script vnode for later use.
2581 			 */
2582 			if (imgp->ip_scriptvp) {
2583 				vnode_put(imgp->ip_scriptvp);
2584 				imgp->ip_scriptvp = NULLVP;
2585 			}
2586 			if (vnode_getwithref(imgp->ip_vp) == 0) {
2587 				imgp->ip_scriptvp = imgp->ip_vp;
2588 			}
2589 #endif
2590 
2591 			nameidone(ndp);
2592 
2593 			vnode_put(imgp->ip_vp);
2594 			imgp->ip_vp = NULL;     /* already put */
2595 			imgp->ip_ndp = NULL; /* already nameidone */
2596 
2597 			/* Use excpath, which exec_shell_imgact reset to the interpreter */
2598 			NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
2599 			    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2600 
2601 			proc_transend(p, 0);
2602 			goto again;
2603 
2604 		default:
2605 			break;
2606 		}
2607 	}
2608 
2609 	if (error == -1) {
2610 		error = ENOEXEC;
2611 	} else if (error == 0) {
2612 		if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
2613 			AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
2614 		}
2615 
2616 		/*
2617 		 * Call out to allow 3rd party notification of exec.
2618 		 * Ignore result of kauth_authorize_fileop call.
2619 		 */
2620 		if (kauth_authorize_fileop_has_listeners()) {
2621 			kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
2622 			    KAUTH_FILEOP_EXEC,
2623 			    (uintptr_t)ndp->ni_vp, 0);
2624 		}
2625 	}
2626 bad:
2627 	proc_transend(p, 0);
2628 
2629 bad_notrans:
2630 	if (imgp->ip_strings) {
2631 		execargs_free(imgp);
2632 	}
2633 	if (imgp->ip_ndp) {
2634 		nameidone(imgp->ip_ndp);
2635 	}
2636 	kfree_type(struct nameidata, ndp);
2637 
2638 	return error;
2639 }
2640 
2641 /*
2642  * exec_validate_spawnattr_policy
2643  *
2644  * Description: Validates the entitlements required to set the apptype.
2645  *
2646  * Parameters:  int psa_apptype         posix spawn attribute apptype
2647  *
2648  * Returns:     0                       Success
2649  *              EPERM                   Failure
2650  */
2651 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)2652 exec_validate_spawnattr_policy(int psa_apptype)
2653 {
2654 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2655 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2656 		if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
2657 			if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
2658 				return EPERM;
2659 			}
2660 		}
2661 	}
2662 
2663 	return 0;
2664 }
2665 
2666 /*
2667  * exec_handle_spawnattr_policy
2668  *
2669  * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
2670  *
2671  * Parameters:  proc_t p                process to apply attributes to
2672  *              int psa_apptype         posix spawn attribute apptype
2673  *
2674  * Returns:     0                       Success
2675  */
2676 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)2677 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2678     task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2679 {
2680 	int apptype     = TASK_APPTYPE_NONE;
2681 	int qos_clamp   = THREAD_QOS_UNSPECIFIED;
2682 	task_role_t role = TASK_UNSPECIFIED;
2683 
2684 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2685 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2686 
2687 		switch (proctype) {
2688 		case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2689 			apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2690 			break;
2691 		case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2692 			apptype = TASK_APPTYPE_DAEMON_STANDARD;
2693 			break;
2694 		case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2695 			apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2696 			break;
2697 		case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2698 			apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2699 			break;
2700 		case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2701 			apptype = TASK_APPTYPE_APP_DEFAULT;
2702 			break;
2703 		case POSIX_SPAWN_PROC_TYPE_DRIVER:
2704 			apptype = TASK_APPTYPE_DRIVER;
2705 			break;
2706 		default:
2707 			apptype = TASK_APPTYPE_NONE;
2708 			/* TODO: Should an invalid value here fail the spawn? */
2709 			break;
2710 		}
2711 	}
2712 
2713 	if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2714 		switch (psa_qos_clamp) {
2715 		case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2716 			qos_clamp = THREAD_QOS_UTILITY;
2717 			break;
2718 		case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2719 			qos_clamp = THREAD_QOS_BACKGROUND;
2720 			break;
2721 		case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2722 			qos_clamp = THREAD_QOS_MAINTENANCE;
2723 			break;
2724 		default:
2725 			qos_clamp = THREAD_QOS_UNSPECIFIED;
2726 			/* TODO: Should an invalid value here fail the spawn? */
2727 			break;
2728 		}
2729 	}
2730 
2731 	if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2732 		proc_darwin_role_to_task_role(psa_darwin_role, &role);
2733 	}
2734 
2735 	if (apptype != TASK_APPTYPE_NONE ||
2736 	    qos_clamp != THREAD_QOS_UNSPECIFIED ||
2737 	    role != TASK_UNSPECIFIED ||
2738 	    port_actions->portwatch_count) {
2739 		proc_set_task_spawnpolicy(proc_task(p), thread, apptype, qos_clamp, role,
2740 		    port_actions->portwatch_array, port_actions->portwatch_count);
2741 	}
2742 
2743 	if (port_actions->registered_count) {
2744 		if (_kernelrpc_mach_ports_register3(proc_task(p),
2745 		    port_actions->registered_array[0],
2746 		    port_actions->registered_array[1],
2747 		    port_actions->registered_array[2])) {
2748 			return EINVAL;
2749 		}
2750 		/* mach_ports_register() consumed the array */
2751 		bzero(port_actions->registered_array,
2752 		    sizeof(port_actions->registered_array));
2753 		port_actions->registered_count = 0;
2754 	}
2755 
2756 	return 0;
2757 }
2758 
2759 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2760 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2761 {
2762 	if (port_actions->excport_array) {
2763 		for (uint32_t i = 0; i < port_actions->exception_port_count; i++) {
2764 			ipc_port_t port = NULL;
2765 			if ((port = port_actions->excport_array[i].port) != NULL) {
2766 				ipc_port_release_send(port);
2767 			}
2768 		}
2769 		kfree_type(struct exception_port_action_t, port_actions->exception_port_count,
2770 		    port_actions->excport_array);
2771 	}
2772 
2773 	if (port_actions->portwatch_array) {
2774 		for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2775 			ipc_port_t port = NULL;
2776 			if ((port = port_actions->portwatch_array[i]) != NULL) {
2777 				ipc_port_release_send(port);
2778 			}
2779 		}
2780 		kfree_type(ipc_port_t, port_actions->portwatch_count,
2781 		    port_actions->portwatch_array);
2782 	}
2783 
2784 	for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2785 		ipc_port_t port = NULL;
2786 		if ((port = port_actions->registered_array[i]) != NULL) {
2787 			ipc_port_release_send(port);
2788 		}
2789 	}
2790 }
2791 
2792 /*
2793  * exec_handle_port_actions
2794  *
2795  * Description:	Go through the _posix_port_actions_t contents,
2796  *              calling task_set_special_port, task_set_exception_ports
2797  *              and/or audit_session_spawnjoin for the current task.
2798  *
2799  * Parameters:	struct image_params *	Image parameter block
2800  *
2801  * Returns:	0			Success
2802  *              EINVAL			Failure
2803  *              ENOTSUP			Illegal posix_spawn attr flag was set
2804  */
2805 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2806 exec_handle_port_actions(struct image_params *imgp,
2807     struct exec_port_actions *actions)
2808 {
2809 	_posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2810 #if CONFIG_AUDIT
2811 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2812 #endif
2813 	_ps_port_action_t *act = NULL;
2814 	task_t task = get_threadtask(imgp->ip_new_thread);
2815 	ipc_port_t port = NULL;
2816 	errno_t ret = 0;
2817 	int i = 0, portwatch_i = 0, registered_i = 0, excport_i = 0;
2818 	kern_return_t kr;
2819 	boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2820 	boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2821 	int ptrauth_task_port_count = 0;
2822 
2823 	for (i = 0; i < pacts->pspa_count; i++) {
2824 		act = &pacts->pspa_actions[i];
2825 
2826 		switch (act->port_type) {
2827 		case PSPA_SPECIAL:
2828 #if CONFIG_AUDIT
2829 		case PSPA_AU_SESSION:
2830 #endif
2831 			break;
2832 		case PSPA_EXCEPTION:
2833 			if (++actions->exception_port_count > TASK_MAX_EXCEPTION_PORT_COUNT) {
2834 				ret = EINVAL;
2835 				goto done;
2836 			}
2837 			break;
2838 		case PSPA_IMP_WATCHPORTS:
2839 			if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
2840 				ret = EINVAL;
2841 				goto done;
2842 			}
2843 			break;
2844 		case PSPA_REGISTERED_PORTS:
2845 			if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
2846 				ret = EINVAL;
2847 				goto done;
2848 			}
2849 			break;
2850 		case PSPA_PTRAUTH_TASK_PORT:
2851 			if (++ptrauth_task_port_count > 1) {
2852 				ret = EINVAL;
2853 				goto done;
2854 			}
2855 			break;
2856 		default:
2857 			ret = EINVAL;
2858 			goto done;
2859 		}
2860 	}
2861 
2862 	if (actions->exception_port_count) {
2863 		actions->excport_array = kalloc_type(struct exception_port_action_t,
2864 		    actions->exception_port_count, Z_WAITOK | Z_ZERO);
2865 
2866 		if (actions->excport_array == NULL) {
2867 			ret = ENOMEM;
2868 			goto done;
2869 		}
2870 	}
2871 	if (actions->portwatch_count) {
2872 		if (in_exec && task_has_watchport_boost) {
2873 			ret = EINVAL;
2874 			goto done;
2875 		}
2876 		actions->portwatch_array = kalloc_type(ipc_port_t,
2877 		    actions->portwatch_count, Z_WAITOK | Z_ZERO);
2878 		if (actions->portwatch_array == NULL) {
2879 			ret = ENOMEM;
2880 			goto done;
2881 		}
2882 	}
2883 
2884 	for (i = 0; i < pacts->pspa_count; i++) {
2885 		act = &pacts->pspa_actions[i];
2886 
2887 		if (MACH_PORT_VALID(act->new_port)) {
2888 			kr = ipc_typed_port_copyin_send(get_task_ipcspace(current_task()),
2889 			    act->new_port, IKOT_UNKNOWN, &port);
2890 
2891 			if (kr != KERN_SUCCESS) {
2892 				ret = EINVAL;
2893 				goto done;
2894 			}
2895 		} else {
2896 			/* it's NULL or DEAD */
2897 			port = CAST_MACH_NAME_TO_PORT(act->new_port);
2898 		}
2899 
2900 		switch (act->port_type) {
2901 		case PSPA_SPECIAL:
2902 			kr = task_set_special_port(task, act->which, port);
2903 
2904 			if (kr != KERN_SUCCESS) {
2905 				ret = EINVAL;
2906 			}
2907 			break;
2908 
2909 #if CONFIG_AUDIT
2910 		case PSPA_AU_SESSION:
2911 			ret = audit_session_spawnjoin(p, port);
2912 			if (ret) {
2913 				/* audit_session_spawnjoin() has already dropped the reference in case of error. */
2914 				goto done;
2915 			}
2916 
2917 			break;
2918 #endif
2919 		case PSPA_EXCEPTION:
2920 			assert(excport_i < actions->exception_port_count);
2921 			/* hold on to this till end of spawn */
2922 			actions->excport_array[excport_i].port_action = act;
2923 			actions->excport_array[excport_i].port = port;
2924 			excport_i++;
2925 			break;
2926 		case PSPA_IMP_WATCHPORTS:
2927 			assert(portwatch_i < actions->portwatch_count);
2928 			/* hold on to this till end of spawn */
2929 			actions->portwatch_array[portwatch_i++] = port;
2930 			break;
2931 		case PSPA_REGISTERED_PORTS:
2932 			assert(registered_i < actions->registered_count);
2933 			/* hold on to this till end of spawn */
2934 			actions->registered_array[registered_i++] = port;
2935 			break;
2936 
2937 		case PSPA_PTRAUTH_TASK_PORT:
2938 #if (DEVELOPMENT || DEBUG)
2939 #if defined(HAS_APPLE_PAC)
2940 			{
2941 				task_t ptr_auth_task = convert_port_to_task(port);
2942 
2943 				if (ptr_auth_task == TASK_NULL) {
2944 					ret = EINVAL;
2945 					break;
2946 				}
2947 
2948 				imgp->ip_inherited_shared_region_id =
2949 				    task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
2950 				    &imgp->ip_inherited_jop_pid);
2951 
2952 				/* Deallocate task ref returned by convert_port_to_task */
2953 				task_deallocate(ptr_auth_task);
2954 			}
2955 #endif /* HAS_APPLE_PAC */
2956 #endif /* (DEVELOPMENT || DEBUG) */
2957 
2958 			/* consume the port right in case of success */
2959 			ipc_port_release_send(port);
2960 			break;
2961 		default:
2962 			ret = EINVAL;
2963 			break;
2964 		}
2965 
2966 		if (ret) {
2967 			/* action failed, so release port resources */
2968 			ipc_port_release_send(port);
2969 			break;
2970 		}
2971 	}
2972 
2973 done:
2974 	if (0 != ret) {
2975 		DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2976 	}
2977 	return ret;
2978 }
2979 
2980 
2981 /*
2982  * exec_handle_exception_port_actions
2983  *
2984  * Description:	Go through the saved exception ports in exec_port_actions,
2985  *              calling task_set_exception_ports for the current Task.
2986  *              This must happen after image activation, and after exec_resettextvp()
2987  *				because task_set_exception_ports checks the `TF_PLATFORM` bit and entitlements.
2988  *
2989  * Parameters:	struct image_params *		Image parameter block
2990  *                              struct exec_port_actions *  Saved Port Actions
2991  *
2992  * Returns:	0			Success
2993  *              EINVAL			task_set_exception_ports failed
2994  */
2995 static errno_t
exec_handle_exception_port_actions(const struct image_params * imgp,const struct exec_port_actions * actions)2996 exec_handle_exception_port_actions(const struct image_params *imgp,
2997     const struct exec_port_actions *actions)
2998 {
2999 	task_t task = get_threadtask(imgp->ip_new_thread);
3000 
3001 	for (int i = 0; i < actions->exception_port_count; i++) {
3002 		ipc_port_t port = actions->excport_array[i].port;
3003 		_ps_port_action_t *act = actions->excport_array[i].port_action;
3004 		assert(act != NULL);
3005 		kern_return_t kr = task_set_exception_ports(task, act->mask, port,
3006 		    act->behavior, act->flavor);
3007 		if (kr != KERN_SUCCESS) {
3008 			DTRACE_PROC1(spawn__exception__port__failure, mach_port_name_t, act->new_port);
3009 			return EINVAL;
3010 		}
3011 		actions->excport_array[i].port = NULL;
3012 	}
3013 
3014 	return 0;
3015 }
3016 
3017 
3018 /*
3019  * exec_handle_file_actions
3020  *
3021  * Description:	Go through the _posix_file_actions_t contents applying the
3022  *		open, close, and dup2 operations to the open file table for
3023  *		the current process.
3024  *
3025  * Parameters:	struct image_params *	Image parameter block
3026  *
3027  * Returns:	0			Success
3028  *		???
3029  *
3030  * Note:	Actions are applied in the order specified, with the credential
3031  *		of the parent process.  This is done to permit the parent
3032  *		process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
3033  *		the child following operations the child may in fact not be
3034  *		normally permitted to perform.
3035  */
3036 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)3037 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
3038 {
3039 	int error = 0;
3040 	int action;
3041 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
3042 	kauth_cred_t p_cred = vfs_context_ucred(imgp->ip_vfs_context);
3043 	_posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
3044 	int ival[2];            /* dummy retval for system calls) */
3045 #if CONFIG_AUDIT
3046 	struct uthread *uthread = current_uthread();
3047 #endif
3048 
3049 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
3050 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3051 
3052 		switch (psfa->psfaa_type) {
3053 		case PSFA_OPEN: {
3054 			/*
3055 			 * Open is different, in that it requires the use of
3056 			 * a path argument, which is normally copied in from
3057 			 * user space; because of this, we have to support an
3058 			 * open from kernel space that passes an address space
3059 			 * context of UIO_SYSSPACE, and casts the address
3060 			 * argument to a user_addr_t.
3061 			 */
3062 			struct vnode_attr *vap;
3063 			struct nameidata *ndp;
3064 			int mode = psfa->psfaa_openargs.psfao_mode;
3065 			int origfd;
3066 			struct {
3067 				struct vnode_attr va;
3068 				struct nameidata nd;
3069 			} *__open_data;
3070 
3071 			__open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
3072 			if (__open_data == NULL) {
3073 				error = ENOMEM;
3074 				break;
3075 			}
3076 
3077 			vap = &__open_data->va;
3078 			ndp = &__open_data->nd;
3079 
3080 			VATTR_INIT(vap);
3081 			/* Mask off all but regular access permissions */
3082 			mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
3083 			VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
3084 
3085 			AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
3086 
3087 			NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
3088 			    CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
3089 			    imgp->ip_vfs_context);
3090 
3091 			error = open1(imgp->ip_vfs_context, ndp,
3092 			    psfa->psfaa_openargs.psfao_oflag,
3093 			    vap, NULL, NULL, &origfd, AUTH_OPEN_NOAUTHFD);
3094 
3095 			kfree_type(typeof(*__open_data), __open_data);
3096 
3097 			AUDIT_SUBCALL_EXIT(uthread, error);
3098 
3099 			/*
3100 			 * If there's an error, or we get the right fd by
3101 			 * accident, then drop out here.  This is easier than
3102 			 * reworking all the open code to preallocate fd
3103 			 * slots, and internally taking one as an argument.
3104 			 */
3105 			if (error || origfd == psfa->psfaa_filedes) {
3106 				break;
3107 			}
3108 
3109 			/*
3110 			 * If we didn't fall out from an error, we ended up
3111 			 * with the wrong fd; so now we've got to try to dup2
3112 			 * it to the right one.
3113 			 */
3114 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
3115 			error = dup2(p, p_cred, origfd, psfa->psfaa_filedes, ival);
3116 			AUDIT_SUBCALL_EXIT(uthread, error);
3117 			if (error) {
3118 				break;
3119 			}
3120 
3121 			/*
3122 			 * Finally, close the original fd.
3123 			 */
3124 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
3125 			error = close_nocancel(p, p_cred, origfd);
3126 			AUDIT_SUBCALL_EXIT(uthread, error);
3127 		}
3128 		break;
3129 
3130 		case PSFA_DUP2: {
3131 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
3132 			error = dup2(p, p_cred, psfa->psfaa_filedes,
3133 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
3134 			AUDIT_SUBCALL_EXIT(uthread, error);
3135 		}
3136 		break;
3137 
3138 		case PSFA_FILEPORT_DUP2: {
3139 			ipc_port_t port;
3140 			kern_return_t kr;
3141 			int origfd;
3142 
3143 			if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
3144 				error = EINVAL;
3145 				break;
3146 			}
3147 
3148 			kr = ipc_typed_port_copyin_send(get_task_ipcspace(current_task()),
3149 			    psfa->psfaa_fileport, IKOT_FILEPORT, &port);
3150 
3151 			if (kr != KERN_SUCCESS) {
3152 				error = EINVAL;
3153 				break;
3154 			}
3155 
3156 			error = fileport_makefd(p, port, 0, &origfd);
3157 
3158 			if (IPC_PORT_NULL != port) {
3159 				ipc_typed_port_release_send(port, IKOT_FILEPORT);
3160 			}
3161 
3162 			if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
3163 				break;
3164 			}
3165 
3166 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
3167 			error = dup2(p, p_cred, origfd,
3168 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
3169 			AUDIT_SUBCALL_EXIT(uthread, error);
3170 			if (error) {
3171 				break;
3172 			}
3173 
3174 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
3175 			error = close_nocancel(p, p_cred, origfd);
3176 			AUDIT_SUBCALL_EXIT(uthread, error);
3177 		}
3178 		break;
3179 
3180 		case PSFA_CLOSE: {
3181 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
3182 			error = close_nocancel(p, p_cred, psfa->psfaa_filedes);
3183 			AUDIT_SUBCALL_EXIT(uthread, error);
3184 		}
3185 		break;
3186 
3187 		case PSFA_INHERIT: {
3188 			struct fileproc *fp;
3189 
3190 			/*
3191 			 * Check to see if the descriptor exists, and
3192 			 * ensure it's -not- marked as close-on-exec.
3193 			 *
3194 			 * Attempting to "inherit" a guarded fd will
3195 			 * result in a error.
3196 			 */
3197 
3198 			proc_fdlock(p);
3199 			if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
3200 				error = EBADF;
3201 			} else if (fp->fp_guard_attrs) {
3202 				error = fp_guard_exception(p, psfa->psfaa_filedes,
3203 				    fp, kGUARD_EXC_NOCLOEXEC);
3204 			} else {
3205 				fp->fp_flags &= ~FP_CLOEXEC;
3206 				error = 0;
3207 			}
3208 			proc_fdunlock(p);
3209 		}
3210 		break;
3211 
3212 		case PSFA_CHDIR: {
3213 			/*
3214 			 * Chdir is different, in that it requires the use of
3215 			 * a path argument, which is normally copied in from
3216 			 * user space; because of this, we have to support a
3217 			 * chdir from kernel space that passes an address space
3218 			 * context of UIO_SYSSPACE, and casts the address
3219 			 * argument to a user_addr_t.
3220 			 */
3221 			struct nameidata *nd;
3222 			nd = kalloc_type(struct nameidata,
3223 			    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3224 
3225 			AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
3226 			NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
3227 			    CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
3228 			    imgp->ip_vfs_context);
3229 
3230 			error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
3231 			kfree_type(struct nameidata, nd);
3232 			AUDIT_SUBCALL_EXIT(uthread, error);
3233 		}
3234 		break;
3235 
3236 		case PSFA_FCHDIR: {
3237 			AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
3238 			error = fchdir(p, imgp->ip_vfs_context,
3239 			    psfa->psfaa_filedes, false);
3240 			AUDIT_SUBCALL_EXIT(uthread, error);
3241 		}
3242 		break;
3243 
3244 		default:
3245 			error = EINVAL;
3246 			break;
3247 		}
3248 
3249 		/* All file actions failures are considered fatal, per POSIX */
3250 
3251 		if (error) {
3252 			if (PSFA_OPEN == psfa->psfaa_type) {
3253 				DTRACE_PROC1(spawn__open__failure, uintptr_t,
3254 				    psfa->psfaa_openargs.psfao_path);
3255 			} else {
3256 				DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
3257 			}
3258 			break;
3259 		}
3260 	}
3261 
3262 	if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
3263 		return error;
3264 	}
3265 
3266 	/*
3267 	 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
3268 	 * this spawn only) as if "close on exec" is the default
3269 	 * disposition of all pre-existing file descriptors.  In this case,
3270 	 * the list of file descriptors mentioned in the file actions
3271 	 * are the only ones that can be inherited, so mark them now.
3272 	 *
3273 	 * The actual closing part comes later, in fdt_exec().
3274 	 */
3275 	proc_fdlock(p);
3276 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
3277 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3278 		int fd = psfa->psfaa_filedes;
3279 
3280 		switch (psfa->psfaa_type) {
3281 		case PSFA_DUP2:
3282 		case PSFA_FILEPORT_DUP2:
3283 			fd = psfa->psfaa_dup2args.psfad_newfiledes;
3284 			OS_FALLTHROUGH;
3285 		case PSFA_OPEN:
3286 		case PSFA_INHERIT:
3287 			*fdflags(p, fd) |= UF_INHERIT;
3288 			break;
3289 
3290 		case PSFA_CLOSE:
3291 		case PSFA_CHDIR:
3292 		case PSFA_FCHDIR:
3293 			/*
3294 			 * Although PSFA_FCHDIR does have a file descriptor, it is not
3295 			 * *creating* one, thus we do not automatically mark it for
3296 			 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
3297 			 * wishes it to be inherited should use the PSFA_INHERIT action
3298 			 * explicitly.
3299 			 */
3300 			break;
3301 		}
3302 	}
3303 	proc_fdunlock(p);
3304 
3305 	return 0;
3306 }
3307 
3308 #if CONFIG_MACF
3309 /*
3310  * Check that the extension's data is within the bounds of the
3311  * allocation storing all extensions' data
3312  */
3313 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)3314 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
3315     const _ps_mac_policy_extension_t *ext)
3316 {
3317 	uint64_t dataend;
3318 
3319 	if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
3320 		return EOVERFLOW;
3321 	}
3322 	if (__improbable(dataend > px_s->datalen)) {
3323 		return EINVAL;
3324 	}
3325 
3326 	return 0;
3327 }
3328 
3329 /*
3330  * exec_spawnattr_getmacpolicyinfo
3331  */
3332 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)3333 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
3334 {
3335 	const struct ip_px_smpx_s *px_s = macextensions;
3336 	const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
3337 	int i;
3338 
3339 	if (px_s == NULL) {
3340 		return NULL;
3341 	}
3342 
3343 	psmx = px_s->array;
3344 	if (psmx == NULL) {
3345 		return NULL;
3346 	}
3347 
3348 	for (i = 0; i < psmx->psmx_count; i++) {
3349 		const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3350 		if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
3351 			if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
3352 				panic("invalid mac policy extension data");
3353 			}
3354 			if (lenp != NULL) {
3355 				*lenp = (size_t)extension->datalen;
3356 			}
3357 			return (void *)((uintptr_t)px_s->data + extension->dataoff);
3358 		}
3359 	}
3360 
3361 	if (lenp != NULL) {
3362 		*lenp = 0;
3363 	}
3364 	return NULL;
3365 }
3366 
3367 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)3368 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
3369     struct ip_px_smpx_s *pxsp)
3370 {
3371 	_posix_spawn_mac_policy_extensions_t psmx = NULL;
3372 	uint8_t *data = NULL;
3373 	uint64_t datalen = 0;
3374 	uint64_t dataoff = 0;
3375 	int error = 0;
3376 
3377 	bzero(pxsp, sizeof(*pxsp));
3378 
3379 	if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
3380 	    px_args->mac_extensions_size > PAGE_SIZE) {
3381 		error = EINVAL;
3382 		goto bad;
3383 	}
3384 
3385 	psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
3386 	if (psmx == NULL) {
3387 		error = ENOMEM;
3388 		goto bad;
3389 	}
3390 
3391 	error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
3392 	if (error) {
3393 		goto bad;
3394 	}
3395 
3396 	size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
3397 	if (extsize == 0 || extsize > px_args->mac_extensions_size) {
3398 		error = EINVAL;
3399 		goto bad;
3400 	}
3401 
3402 	for (int i = 0; i < psmx->psmx_count; i++) {
3403 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3404 		if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
3405 			error = EINVAL;
3406 			goto bad;
3407 		}
3408 		if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
3409 			error = ENOMEM;
3410 			goto bad;
3411 		}
3412 	}
3413 
3414 	data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
3415 	if (data == NULL) {
3416 		error = ENOMEM;
3417 		goto bad;
3418 	}
3419 
3420 	for (int i = 0; i < psmx->psmx_count; i++) {
3421 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3422 
3423 #if !__LP64__
3424 		if (extension->data > UINT32_MAX) {
3425 			goto bad;
3426 		}
3427 #endif
3428 		error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
3429 		if (error) {
3430 			error = ENOMEM;
3431 			goto bad;
3432 		}
3433 		extension->dataoff = dataoff;
3434 		dataoff += extension->datalen;
3435 	}
3436 
3437 	pxsp->array = psmx;
3438 	pxsp->data = data;
3439 	pxsp->datalen = datalen;
3440 	return 0;
3441 
3442 bad:
3443 	kfree_data(psmx, px_args->mac_extensions_size);
3444 	kfree_data(data, (vm_size_t)datalen);
3445 	return error;
3446 }
3447 #endif /* CONFIG_MACF */
3448 
3449 #if CONFIG_COALITIONS
3450 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])3451 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
3452 {
3453 	for (int c = 0; c < COALITION_NUM_TYPES; c++) {
3454 		if (coal[c]) {
3455 			coalition_remove_active(coal[c]);
3456 			coalition_release(coal[c]);
3457 		}
3458 	}
3459 }
3460 #endif
3461 
3462 #if CONFIG_PERSONAS
3463 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)3464 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
3465 {
3466 	int error = 0;
3467 	struct persona *persona = NULL;
3468 	kauth_cred_t mycred = kauth_cred_get();
3469 
3470 	if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
3471 		return EPERM;
3472 	}
3473 
3474 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3475 		if (px_persona->pspi_ngroups > NGROUPS_MAX) {
3476 			return EINVAL;
3477 		}
3478 	}
3479 
3480 	persona = persona_lookup(px_persona->pspi_id);
3481 	if (!persona) {
3482 		return ESRCH;
3483 	}
3484 
3485 	// non-root process should not be allowed to set persona with uid/gid 0
3486 	if (!kauth_cred_issuser(mycred) &&
3487 	    (px_persona->pspi_uid == 0 || px_persona->pspi_gid == 0)) {
3488 		return EPERM;
3489 	}
3490 
3491 	persona_put(persona);
3492 	return error;
3493 }
3494 
3495 static bool
kauth_cred_model_setpersona(kauth_cred_t model,struct _posix_spawn_persona_info * px_persona)3496 kauth_cred_model_setpersona(
3497 	kauth_cred_t            model,
3498 	struct _posix_spawn_persona_info *px_persona)
3499 {
3500 	bool updated = false;
3501 
3502 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
3503 		updated |= kauth_cred_model_setresuid(model,
3504 		    px_persona->pspi_uid,
3505 		    px_persona->pspi_uid,
3506 		    px_persona->pspi_uid,
3507 		    KAUTH_UID_NONE);
3508 	}
3509 
3510 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
3511 		updated |= kauth_cred_model_setresgid(model,
3512 		    px_persona->pspi_gid,
3513 		    px_persona->pspi_gid,
3514 		    px_persona->pspi_gid);
3515 	}
3516 
3517 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3518 		updated |= kauth_cred_model_setgroups(model,
3519 		    px_persona->pspi_groups,
3520 		    px_persona->pspi_ngroups,
3521 		    px_persona->pspi_gmuid);
3522 	}
3523 
3524 	return updated;
3525 }
3526 
3527 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)3528 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
3529 {
3530 	struct persona *persona = NULL;
3531 
3532 	/*
3533 	 * we want to spawn into the given persona, but we want to override
3534 	 * the kauth with a different UID/GID combo
3535 	 */
3536 	persona = persona_lookup(px_persona->pspi_id);
3537 	if (!persona) {
3538 		return ESRCH;
3539 	}
3540 
3541 	return persona_proc_adopt(p, persona,
3542 	           ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
3543 		return kauth_cred_model_setpersona(model, px_persona);
3544 	});
3545 }
3546 #endif
3547 
3548 #if __arm64__
3549 #if DEVELOPMENT || DEBUG
3550 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
3551     LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
3552 
3553 __startup_func
3554 static void
legacy_footprint_entitlement_mode_init(void)3555 legacy_footprint_entitlement_mode_init(void)
3556 {
3557 	/*
3558 	 * legacy_footprint_entitlement_mode specifies the behavior we want associated
3559 	 * with the entitlement. The supported modes are:
3560 	 *
3561 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3562 	 *	Indicates that we want every process to have the memory accounting
3563 	 *	that is available in iOS 12.0 and beyond.
3564 	 *
3565 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3566 	 *	Indicates that for every process that has the 'legacy footprint entitlement',
3567 	 *      we want to give it the old iOS 11.0 accounting behavior which accounted some
3568 	 *	of the process's memory to the kernel.
3569 	 *
3570 	 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3571 	 *      Indicates that for every process that has the 'legacy footprint entitlement',
3572 	 *	we want it to have a higher memory limit which will help them acclimate to the
3573 	 *	iOS 12.0 (& beyond) accounting behavior that does the right accounting.
3574 	 *      The bonus added to the system-wide task limit to calculate this higher memory limit
3575 	 *      is available in legacy_footprint_bonus_mb.
3576 	 */
3577 
3578 	if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
3579 	    legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
3580 		legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
3581 	}
3582 }
3583 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
3584 #else
3585 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
3586 #endif
3587 
3588 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)3589 proc_legacy_footprint_entitled(proc_t p, task_t task)
3590 {
3591 #pragma unused(p)
3592 	boolean_t legacy_footprint_entitled;
3593 
3594 	switch (legacy_footprint_entitlement_mode) {
3595 	case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3596 		/* the entitlement is ignored */
3597 		break;
3598 	case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3599 		/* the entitlement grants iOS11 legacy accounting */
3600 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3601 		if (legacy_footprint_entitled) {
3602 			task_set_legacy_footprint(task);
3603 		}
3604 		break;
3605 	case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3606 		/* the entitlement grants a footprint limit increase */
3607 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3608 		if (legacy_footprint_entitled) {
3609 			task_set_extra_footprint_limit(task);
3610 		}
3611 		break;
3612 	default:
3613 		break;
3614 	}
3615 }
3616 
3617 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)3618 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
3619 {
3620 #pragma unused(p)
3621 	boolean_t ios13extended_footprint_entitled;
3622 
3623 	/* the entitlement grants a footprint limit increase */
3624 	ios13extended_footprint_entitled = memorystatus_task_has_ios13extended_footprint_limit(proc_task(p));
3625 	if (ios13extended_footprint_entitled) {
3626 		task_set_ios13extended_footprint_limit(task);
3627 	}
3628 }
3629 
3630 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)3631 proc_increased_memory_limit_entitled(proc_t p, task_t task)
3632 {
3633 	if (memorystatus_task_has_increased_debugging_memory_limit_entitlement(task)) {
3634 		memorystatus_act_on_entitled_developer_task_limit(p);
3635 	} else if (memorystatus_task_has_increased_memory_limit_entitlement(task)) {
3636 		memorystatus_act_on_entitled_task_limit(p);
3637 	}
3638 }
3639 
3640 /*
3641  * Check for any of the various entitlements that permit a higher
3642  * task footprint limit or alternate accounting and apply them.
3643  */
3644 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)3645 proc_footprint_entitlement_hacks(proc_t p, task_t task)
3646 {
3647 	proc_legacy_footprint_entitled(p, task);
3648 	proc_ios13extended_footprint_entitled(p, task);
3649 	proc_increased_memory_limit_entitled(p, task);
3650 }
3651 #endif /* __arm64__ */
3652 
3653 /*
3654  * Processes with certain entitlements are granted a jumbo-size VM map.
3655  */
3656 static inline void
proc_apply_jit_and_vm_policies(struct image_params * imgp,proc_t p,task_t task)3657 proc_apply_jit_and_vm_policies(struct image_params *imgp, proc_t p, task_t task)
3658 {
3659 #if CONFIG_MACF
3660 	bool jit_entitled = false;
3661 #endif /* CONFIG_MACF */
3662 	bool needs_jumbo_va = false;
3663 	bool needs_extra_jumbo_va = false;
3664 	struct _posix_spawnattr *psa = imgp->ip_px_sa;
3665 
3666 #if CONFIG_MACF
3667 	jit_entitled = (mac_proc_check_map_anon(p, proc_ucred_unsafe(p),
3668 	    0, 0, 0, MAP_JIT, NULL) == 0);
3669 	needs_jumbo_va = jit_entitled || IOTaskHasEntitlement(task,
3670 	    "com.apple.developer.kernel.extended-virtual-addressing") ||
3671 	    memorystatus_task_has_increased_memory_limit_entitlement(task) ||
3672 	    memorystatus_task_has_increased_debugging_memory_limit_entitlement(task);
3673 #else
3674 #pragma unused(p)
3675 #endif /* CONFIG_MACF */
3676 
3677 
3678 	if (needs_jumbo_va) {
3679 		vm_map_set_jumbo(get_task_map(task));
3680 	}
3681 
3682 	if (psa && psa->psa_max_addr) {
3683 		vm_map_set_max_addr(get_task_map(task), psa->psa_max_addr, false);
3684 	}
3685 
3686 #if CONFIG_MAP_RANGES
3687 	if (task_is_hardened_binary(task) && !proc_is_simulated(p)) {
3688 		/*
3689 		 * This must be done last as it needs to observe
3690 		 * any kind of VA space growth that was requested.
3691 		 * This is used by the secure allocator, so
3692 		 * must be applied to all hardened binaries
3693 		 */
3694 #if XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT
3695 		needs_extra_jumbo_va = IOTaskHasEntitlement(task,
3696 		    "com.apple.kernel.large-file-virtual-addressing");
3697 #endif /* XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT */
3698 		vm_map_range_configure(get_task_map(task), needs_extra_jumbo_va);
3699 	}
3700 #else
3701 #pragma unused(needs_extra_jumbo_va)
3702 #endif /* CONFIG_MAP_RANGES */
3703 
3704 #if CONFIG_MACF
3705 	if (jit_entitled) {
3706 		vm_map_set_jit_entitled(get_task_map(task));
3707 
3708 	}
3709 #endif /* CONFIG_MACF */
3710 
3711 #if XNU_TARGET_OS_OSX
3712 	/* TPRO cannot be enforced on binaries that load 3P plugins on macos - rdar://107420220 */
3713 	const bool task_loads_3P_plugins = imgp->ip_flags & IMGPF_3P_PLUGINS;
3714 #endif /* XNU_TARGET_OS_OSX */
3715 
3716 	if (task_is_hardened_binary(task)
3717 #if XNU_TARGET_OS_OSX
3718 	    && !task_loads_3P_plugins
3719 #endif /* XNU_TARGET_OS_OSX */
3720 	    ) {
3721 		/*
3722 		 * Pre-emptively disable TPRO remapping for
3723 		 * hardened binaries (which do not load 3P plugins)
3724 		 */
3725 		vm_map_set_tpro_enforcement(get_task_map(task));
3726 	}
3727 }
3728 
3729 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)3730 spawn_posix_cred_adopt(proc_t p,
3731     struct _posix_spawn_posix_cred_info *px_pcred_info)
3732 {
3733 	int error = 0;
3734 
3735 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3736 		struct setgid_args args = {
3737 			.gid = px_pcred_info->pspci_gid,
3738 		};
3739 		error = setgid(p, &args, NULL);
3740 		if (error) {
3741 			return error;
3742 		}
3743 	}
3744 
3745 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3746 		error = setgroups_internal(p,
3747 		    px_pcred_info->pspci_ngroups,
3748 		    px_pcred_info->pspci_groups,
3749 		    px_pcred_info->pspci_gmuid);
3750 		if (error) {
3751 			return error;
3752 		}
3753 	}
3754 
3755 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3756 		struct setuid_args args = {
3757 			.uid = px_pcred_info->pspci_uid,
3758 		};
3759 		error = setuid(p, &args, NULL);
3760 		if (error) {
3761 			return error;
3762 		}
3763 	}
3764 	return 0;
3765 }
3766 
3767 
3768 /*
3769  * posix_spawn
3770  *
3771  * Parameters:	uap->pid		Pointer to pid return area
3772  *		uap->fname		File name to exec
3773  *		uap->argp		Argument list
3774  *		uap->envp		Environment list
3775  *
3776  * Returns:	0			Success
3777  *		EINVAL			Invalid argument
3778  *		ENOTSUP			Not supported
3779  *		ENOEXEC			Executable file format error
3780  *	exec_activate_image:EINVAL	Invalid argument
3781  *	exec_activate_image:EACCES	Permission denied
3782  *	exec_activate_image:EINTR	Interrupted function
3783  *	exec_activate_image:ENOMEM	Not enough space
3784  *	exec_activate_image:EFAULT	Bad address
3785  *	exec_activate_image:ENAMETOOLONG	Filename too long
3786  *	exec_activate_image:ENOEXEC	Executable file format error
3787  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
3788  *	exec_activate_image:EAUTH	Image decryption failed
3789  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
3790  *	exec_activate_image:???
3791  *	mac_execve_enter:???
3792  *
3793  * TODO:	Expect to need __mac_posix_spawn() at some point...
3794  *		Handle posix_spawnattr_t
3795  *		Handle posix_spawn_file_actions_t
3796  */
3797 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3798 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3799 {
3800 	proc_t p = ap;
3801 	user_addr_t pid = uap->pid;
3802 	int ival[2];            /* dummy retval for setpgid() */
3803 	char *subsystem_root_path = NULL;
3804 	struct image_params *imgp = NULL;
3805 	struct vnode_attr *vap = NULL;
3806 	struct vnode_attr *origvap = NULL;
3807 	struct uthread  *uthread = 0;   /* compiler complains if not set to 0*/
3808 	int error, sig;
3809 	int is_64 = IS_64BIT_PROCESS(p);
3810 	struct vfs_context context;
3811 	struct user__posix_spawn_args_desc px_args = {};
3812 	struct _posix_spawnattr px_sa = {};
3813 	_posix_spawn_file_actions_t px_sfap = NULL;
3814 	_posix_spawn_port_actions_t px_spap = NULL;
3815 	struct __kern_sigaction vec;
3816 	boolean_t spawn_no_exec = FALSE;
3817 	boolean_t proc_transit_set = TRUE;
3818 	boolean_t proc_signal_set = TRUE;
3819 	boolean_t exec_done = FALSE;
3820 	os_reason_t exec_failure_reason = NULL;
3821 
3822 	struct exec_port_actions port_actions = { };
3823 	vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3824 	task_t old_task = current_task();
3825 	task_t new_task = NULL;
3826 	boolean_t should_release_proc_ref = FALSE;
3827 	void *inherit = NULL;
3828 	uint8_t crash_behavior = 0;
3829 	uint64_t crash_behavior_deadline = 0;
3830 #if CONFIG_EXCLAVES
3831 	char *task_conclave_id = NULL;
3832 #endif
3833 #if CONFIG_PERSONAS
3834 	struct _posix_spawn_persona_info *px_persona = NULL;
3835 #endif
3836 	struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3837 	struct {
3838 		struct image_params imgp;
3839 		struct vnode_attr va;
3840 		struct vnode_attr origva;
3841 	} *__spawn_data;
3842 
3843 	/*
3844 	 * Allocate a big chunk for locals instead of using stack since these
3845 	 * structures are pretty big.
3846 	 */
3847 	__spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3848 	if (__spawn_data == NULL) {
3849 		error = ENOMEM;
3850 		goto bad;
3851 	}
3852 	imgp = &__spawn_data->imgp;
3853 	vap = &__spawn_data->va;
3854 	origvap = &__spawn_data->origva;
3855 
3856 	/* Initialize the common data in the image_params structure */
3857 	imgp->ip_user_fname = uap->path;
3858 	imgp->ip_user_argv = uap->argv;
3859 	imgp->ip_user_envv = uap->envp;
3860 	imgp->ip_vattr = vap;
3861 	imgp->ip_origvattr = origvap;
3862 	imgp->ip_vfs_context = &context;
3863 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3864 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3865 	imgp->ip_mac_return = 0;
3866 	imgp->ip_px_persona = NULL;
3867 	imgp->ip_px_pcred_info = NULL;
3868 	imgp->ip_cs_error = OS_REASON_NULL;
3869 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3870 	imgp->ip_subsystem_root_path = NULL;
3871 	imgp->ip_inherited_shared_region_id = NULL;
3872 	imgp->ip_inherited_jop_pid = 0;
3873 	uthread_set_exec_data(current_uthread(), imgp);
3874 
3875 	if (uap->adesc != USER_ADDR_NULL) {
3876 		if (is_64) {
3877 			error = copyin(uap->adesc, &px_args, sizeof(px_args));
3878 		} else {
3879 			struct user32__posix_spawn_args_desc px_args32;
3880 
3881 			error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3882 
3883 			/*
3884 			 * Convert arguments descriptor from external 32 bit
3885 			 * representation to internal 64 bit representation
3886 			 */
3887 			px_args.attr_size = px_args32.attr_size;
3888 			px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3889 			px_args.file_actions_size = px_args32.file_actions_size;
3890 			px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3891 			px_args.port_actions_size = px_args32.port_actions_size;
3892 			px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3893 			px_args.mac_extensions_size = px_args32.mac_extensions_size;
3894 			px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3895 			px_args.coal_info_size = px_args32.coal_info_size;
3896 			px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3897 			px_args.persona_info_size = px_args32.persona_info_size;
3898 			px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3899 			px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3900 			px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3901 			px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3902 			px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3903 			px_args.conclave_id_size = px_args32.conclave_id_size;
3904 			px_args.conclave_id = CAST_USER_ADDR_T(px_args32.conclave_id);
3905 		}
3906 		if (error) {
3907 			goto bad;
3908 		}
3909 
3910 		if (px_args.attr_size != 0) {
3911 			/*
3912 			 * We are not copying the port_actions pointer,
3913 			 * because we already have it from px_args.
3914 			 * This is a bit fragile: <rdar://problem/16427422>
3915 			 */
3916 
3917 			if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3918 				goto bad;
3919 			}
3920 
3921 			imgp->ip_px_sa = &px_sa;
3922 		}
3923 		if (px_args.file_actions_size != 0) {
3924 			/* Limit file_actions to allowed number of open files */
3925 			size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3926 
3927 			if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3928 			    maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3929 				error = EINVAL;
3930 				goto bad;
3931 			}
3932 
3933 			px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3934 			if (px_sfap == NULL) {
3935 				error = ENOMEM;
3936 				goto bad;
3937 			}
3938 			imgp->ip_px_sfa = px_sfap;
3939 
3940 			if ((error = copyin(px_args.file_actions, px_sfap,
3941 			    px_args.file_actions_size)) != 0) {
3942 				goto bad;
3943 			}
3944 
3945 			/* Verify that the action count matches the struct size */
3946 			size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3947 			if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3948 				error = EINVAL;
3949 				goto bad;
3950 			}
3951 		}
3952 		if (px_args.port_actions_size != 0) {
3953 			/* Limit port_actions to one page of data */
3954 			if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3955 			    px_args.port_actions_size > PAGE_SIZE) {
3956 				error = EINVAL;
3957 				goto bad;
3958 			}
3959 
3960 			px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3961 			if (px_spap == NULL) {
3962 				error = ENOMEM;
3963 				goto bad;
3964 			}
3965 			imgp->ip_px_spa = px_spap;
3966 
3967 			if ((error = copyin(px_args.port_actions, px_spap,
3968 			    px_args.port_actions_size)) != 0) {
3969 				goto bad;
3970 			}
3971 
3972 			/* Verify that the action count matches the struct size */
3973 			size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3974 			if (pasize == 0 || pasize != px_args.port_actions_size) {
3975 				error = EINVAL;
3976 				goto bad;
3977 			}
3978 		}
3979 #if CONFIG_PERSONAS
3980 		/* copy in the persona info */
3981 		if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3982 			/* for now, we need the exact same struct in user space */
3983 			if (px_args.persona_info_size != sizeof(*px_persona)) {
3984 				error = ERANGE;
3985 				goto bad;
3986 			}
3987 
3988 			px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3989 			if (px_persona == NULL) {
3990 				error = ENOMEM;
3991 				goto bad;
3992 			}
3993 			imgp->ip_px_persona = px_persona;
3994 
3995 			if ((error = copyin(px_args.persona_info, px_persona,
3996 			    px_args.persona_info_size)) != 0) {
3997 				goto bad;
3998 			}
3999 			if ((error = spawn_validate_persona(px_persona)) != 0) {
4000 				goto bad;
4001 			}
4002 		}
4003 #endif
4004 		/* copy in the posix cred info */
4005 		if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
4006 			/* for now, we need the exact same struct in user space */
4007 			if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
4008 				error = ERANGE;
4009 				goto bad;
4010 			}
4011 
4012 			if (!kauth_cred_issuser(kauth_cred_get())) {
4013 				error = EPERM;
4014 				goto bad;
4015 			}
4016 
4017 			px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
4018 			if (px_pcred_info == NULL) {
4019 				error = ENOMEM;
4020 				goto bad;
4021 			}
4022 			imgp->ip_px_pcred_info = px_pcred_info;
4023 
4024 			if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
4025 			    px_args.posix_cred_info_size)) != 0) {
4026 				goto bad;
4027 			}
4028 
4029 			if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
4030 				if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
4031 					error = EINVAL;
4032 					goto bad;
4033 				}
4034 			}
4035 		}
4036 #if CONFIG_MACF
4037 		if (px_args.mac_extensions_size != 0) {
4038 			if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
4039 				goto bad;
4040 			}
4041 		}
4042 #endif /* CONFIG_MACF */
4043 		if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
4044 			/*
4045 			 * If a valid-looking subsystem root has been
4046 			 * specified...
4047 			 */
4048 			if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
4049 				/*
4050 				 * ...AND the parent has the entitlement, copy
4051 				 * the subsystem root path in.
4052 				 */
4053 				subsystem_root_path = zalloc_flags(ZV_NAMEI,
4054 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
4055 
4056 				if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
4057 					goto bad;
4058 				}
4059 
4060 				/* Paranoia */
4061 				subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
4062 			}
4063 		}
4064 #if CONFIG_EXCLAVES
4065 
4066 		/*
4067 		 * Calling exclaves_boot_wait() ensures that the conclave name
4068 		 * id will only be set when exclaves are actually
4069 		 * supported/enabled. In practice this will never actually block
4070 		 * as by the time this is called the system will have booted to
4071 		 * EXCLAVECORE if it's supported/enabled.
4072 		 */
4073 		if ((px_args.conclave_id_size > 0) && (px_args.conclave_id_size <= MAXCONCLAVENAME) &&
4074 		    (exclaves_boot_wait(EXCLAVES_BOOT_STAGE_EXCLAVECORE) == KERN_SUCCESS)) {
4075 			if (px_args.conclave_id) {
4076 				if (imgp->ip_px_sa != NULL && (px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
4077 					/* Conclave id could be set only for true spawn */
4078 					error = EINVAL;
4079 					goto bad;
4080 				}
4081 				task_conclave_id = kalloc_data(MAXCONCLAVENAME,
4082 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
4083 				if ((error = copyin(px_args.conclave_id, task_conclave_id, MAXCONCLAVENAME))) {
4084 					goto bad;
4085 				}
4086 				task_conclave_id[MAXCONCLAVENAME - 1] = 0;
4087 			}
4088 		}
4089 #endif
4090 	}
4091 
4092 	if (IOTaskHasEntitlement(old_task, SPAWN_SET_PANIC_CRASH_BEHAVIOR)) {
4093 		/* Truncate to uint8_t since we only support 2 flags for now */
4094 		crash_behavior = (uint8_t)px_sa.psa_crash_behavior;
4095 		crash_behavior_deadline = px_sa.psa_crash_behavior_deadline;
4096 	}
4097 
4098 	/* set uthread to parent */
4099 	uthread = current_uthread();
4100 
4101 	/*
4102 	 * <rdar://6640530>; this does not result in a behaviour change
4103 	 * relative to Leopard, so there should not be any existing code
4104 	 * which depends on it.
4105 	 */
4106 
4107 	if (imgp->ip_px_sa != NULL) {
4108 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4109 		if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
4110 			imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
4111 		}
4112 #if (DEVELOPMENT || DEBUG)
4113 		if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
4114 			imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
4115 		}
4116 #endif
4117 
4118 		if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
4119 			goto bad;
4120 		}
4121 	}
4122 
4123 	/*
4124 	 * If we don't have the extension flag that turns "posix_spawn()"
4125 	 * into "execve() with options", then we will be creating a new
4126 	 * process which does not inherit memory from the parent process,
4127 	 * which is one of the most expensive things about using fork()
4128 	 * and execve().
4129 	 */
4130 	if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
4131 		/* Set the new task's coalition, if it is requested.  */
4132 		coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
4133 #if CONFIG_COALITIONS
4134 		int i, ncoals;
4135 		kern_return_t kr = KERN_SUCCESS;
4136 		struct _posix_spawn_coalition_info coal_info;
4137 		int coal_role[COALITION_NUM_TYPES];
4138 
4139 		if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
4140 			goto do_fork1;
4141 		}
4142 
4143 		memset(&coal_info, 0, sizeof(coal_info));
4144 
4145 		if (px_args.coal_info_size > sizeof(coal_info)) {
4146 			px_args.coal_info_size = sizeof(coal_info);
4147 		}
4148 		error = copyin(px_args.coal_info,
4149 		    &coal_info, px_args.coal_info_size);
4150 		if (error != 0) {
4151 			goto bad;
4152 		}
4153 
4154 		ncoals = 0;
4155 		for (i = 0; i < COALITION_NUM_TYPES; i++) {
4156 			uint64_t cid = coal_info.psci_info[i].psci_id;
4157 			if (cid != 0) {
4158 				/*
4159 				 * don't allow tasks which are not in a
4160 				 * privileged coalition to spawn processes
4161 				 * into coalitions other than their own
4162 				 */
4163 				if (!task_is_in_privileged_coalition(proc_task(p), i) &&
4164 				    !IOTaskHasEntitlement(proc_task(p), COALITION_SPAWN_ENTITLEMENT)) {
4165 					coal_dbg("ERROR: %d not in privilegd "
4166 					    "coalition of type %d",
4167 					    proc_getpid(p), i);
4168 					spawn_coalitions_release_all(coal);
4169 					error = EPERM;
4170 					goto bad;
4171 				}
4172 
4173 				coal_dbg("searching for coalition id:%llu", cid);
4174 				/*
4175 				 * take a reference and activation on the
4176 				 * coalition to guard against free-while-spawn
4177 				 * races
4178 				 */
4179 				coal[i] = coalition_find_and_activate_by_id(cid);
4180 				if (coal[i] == COALITION_NULL) {
4181 					coal_dbg("could not find coalition id:%llu "
4182 					    "(perhaps it has been terminated or reaped)", cid);
4183 					/*
4184 					 * release any other coalition's we
4185 					 * may have a reference to
4186 					 */
4187 					spawn_coalitions_release_all(coal);
4188 					error = ESRCH;
4189 					goto bad;
4190 				}
4191 				if (coalition_type(coal[i]) != i) {
4192 					coal_dbg("coalition with id:%lld is not of type:%d"
4193 					    " (it's type:%d)", cid, i, coalition_type(coal[i]));
4194 					spawn_coalitions_release_all(coal);
4195 					error = ESRCH;
4196 					goto bad;
4197 				}
4198 				coal_role[i] = coal_info.psci_info[i].psci_role;
4199 				ncoals++;
4200 			}
4201 		}
4202 		if (ncoals < COALITION_NUM_TYPES) {
4203 			/*
4204 			 * If the user is attempting to spawn into a subset of
4205 			 * the known coalition types, then make sure they have
4206 			 * _at_least_ specified a resource coalition. If not,
4207 			 * the following fork1() call will implicitly force an
4208 			 * inheritance from 'p' and won't actually spawn the
4209 			 * new task into the coalitions the user specified.
4210 			 * (also the call to coalitions_set_roles will panic)
4211 			 */
4212 			if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
4213 				spawn_coalitions_release_all(coal);
4214 				error = EINVAL;
4215 				goto bad;
4216 			}
4217 		}
4218 do_fork1:
4219 #endif /* CONFIG_COALITIONS */
4220 
4221 		/*
4222 		 * note that this will implicitly inherit the
4223 		 * caller's persona (if it exists)
4224 		 */
4225 		error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
4226 		/* returns a thread and task reference */
4227 
4228 		if (error == 0) {
4229 			new_task = get_threadtask(imgp->ip_new_thread);
4230 		}
4231 #if CONFIG_COALITIONS
4232 		/* set the roles of this task within each given coalition */
4233 		if (error == 0) {
4234 			kr = coalitions_set_roles(coal, new_task, coal_role);
4235 			if (kr != KERN_SUCCESS) {
4236 				error = EINVAL;
4237 			}
4238 			if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
4239 			    MACH_COALITION_ADOPT))) {
4240 				for (i = 0; i < COALITION_NUM_TYPES; i++) {
4241 					if (coal[i] != COALITION_NULL) {
4242 						/*
4243 						 * On 32-bit targets, uniqueid
4244 						 * will get truncated to 32 bits
4245 						 */
4246 						KDBG_RELEASE(MACHDBG_CODE(
4247 							    DBG_MACH_COALITION,
4248 							    MACH_COALITION_ADOPT),
4249 						    coalition_id(coal[i]),
4250 						    get_task_uniqueid(new_task));
4251 					}
4252 				}
4253 			}
4254 		}
4255 
4256 		/* drop our references and activations - fork1() now holds them */
4257 		spawn_coalitions_release_all(coal);
4258 #endif /* CONFIG_COALITIONS */
4259 		if (error != 0) {
4260 			goto bad;
4261 		}
4262 		imgp->ip_flags |= IMGPF_SPAWN;  /* spawn w/o exec */
4263 		spawn_no_exec = TRUE;           /* used in later tests */
4264 	} else {
4265 		/* Adjust the user proc count */
4266 		(void)chgproccnt(kauth_getruid(), 1);
4267 		/*
4268 		 * For execve case, create a new proc, task and thread
4269 		 * but don't make the proc visible to userland. After
4270 		 * image activation, the new proc would take place of
4271 		 * the old proc in pid hash and other lists that make
4272 		 * the proc visible to the system.
4273 		 */
4274 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
4275 
4276 		/* task and thread ref returned by cloneproc */
4277 		if (imgp->ip_new_thread == NULL) {
4278 			(void)chgproccnt(kauth_getruid(), -1);
4279 			error = ENOMEM;
4280 			goto bad;
4281 		}
4282 
4283 		new_task = get_threadtask(imgp->ip_new_thread);
4284 		imgp->ip_flags |= IMGPF_EXEC;
4285 	}
4286 
4287 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
4288 
4289 	if (spawn_no_exec) {
4290 		/*
4291 		 * We had to wait until this point before firing the
4292 		 * proc:::create probe, otherwise p would not point to the
4293 		 * child process.
4294 		 */
4295 		DTRACE_PROC1(create, proc_t, p);
4296 	}
4297 	assert(p != NULL);
4298 
4299 	if (subsystem_root_path) {
4300 		/* If a subsystem root was specified, swap it in */
4301 		char * old_subsystem_root_path = p->p_subsystem_root_path;
4302 		p->p_subsystem_root_path = subsystem_root_path;
4303 		subsystem_root_path = old_subsystem_root_path;
4304 	}
4305 
4306 	p->p_crash_behavior = crash_behavior;
4307 	p->p_crash_behavior_deadline = crash_behavior_deadline;
4308 
4309 	p->p_crash_count = px_sa.psa_crash_count;
4310 	p->p_throttle_timeout = px_sa.psa_throttle_timeout;
4311 
4312 	/* We'll need the subsystem root for setting up Apple strings */
4313 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4314 
4315 	context.vc_thread = imgp->ip_new_thread;
4316 	context.vc_ucred = proc_ucred_unsafe(p);  /* in init */
4317 
4318 	/*
4319 	 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
4320 	 * to handle the file_actions.
4321 	 */
4322 
4323 	/* Has spawn file actions? */
4324 	if (imgp->ip_px_sfa != NULL) {
4325 		/*
4326 		 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
4327 		 * is handled in exec_handle_file_actions().
4328 		 */
4329 #if CONFIG_AUDIT
4330 		/*
4331 		 * The file actions auditing can overwrite the upath of
4332 		 * AUE_POSIX_SPAWN audit record.  Save the audit record.
4333 		 */
4334 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4335 		uthread->uu_ar = NULL;
4336 #endif
4337 		error = exec_handle_file_actions(imgp,
4338 		    imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
4339 #if CONFIG_AUDIT
4340 		/* Restore the AUE_POSIX_SPAWN audit record. */
4341 		uthread->uu_ar = save_uu_ar;
4342 #endif
4343 		if (error != 0) {
4344 			goto bad;
4345 		}
4346 	}
4347 
4348 	/* Has spawn port actions? */
4349 	if (imgp->ip_px_spa != NULL) {
4350 #if CONFIG_AUDIT
4351 		/*
4352 		 * Do the same for the port actions as we did for the file
4353 		 * actions.  Save the AUE_POSIX_SPAWN audit record.
4354 		 */
4355 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4356 		uthread->uu_ar = NULL;
4357 #endif
4358 		error = exec_handle_port_actions(imgp, &port_actions);
4359 #if CONFIG_AUDIT
4360 		/* Restore the AUE_POSIX_SPAWN audit record. */
4361 		uthread->uu_ar = save_uu_ar;
4362 #endif
4363 		if (error != 0) {
4364 			goto bad;
4365 		}
4366 	}
4367 
4368 	/* Has spawn attr? */
4369 	if (imgp->ip_px_sa != NULL) {
4370 		/*
4371 		 * Reset UID/GID to parent's RUID/RGID; This works only
4372 		 * because the operation occurs before the call
4373 		 * to exec_handle_sugid() by the image activator called
4374 		 * from exec_activate_image().
4375 		 *
4376 		 * POSIX requires that any setuid/setgid bits on the process
4377 		 * image will take precedence over the spawn attributes
4378 		 * (re)setting them.
4379 		 *
4380 		 * Modifications to p_ucred must be guarded using the
4381 		 * proc's ucred lock. This prevents others from accessing
4382 		 * a garbage credential.
4383 		 */
4384 		if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
4385 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
4386 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model){
4387 				return kauth_cred_model_setuidgid(model,
4388 				kauth_cred_getruid(parent),
4389 				kauth_cred_getrgid(parent));
4390 			});
4391 		}
4392 
4393 		if (imgp->ip_px_pcred_info) {
4394 			if (!spawn_no_exec) {
4395 				error = ENOTSUP;
4396 				goto bad;
4397 			}
4398 
4399 			error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
4400 			if (error != 0) {
4401 				goto bad;
4402 			}
4403 		}
4404 
4405 #if CONFIG_PERSONAS
4406 		if (imgp->ip_px_persona != NULL) {
4407 			if (!spawn_no_exec) {
4408 				error = ENOTSUP;
4409 				goto bad;
4410 			}
4411 
4412 			/*
4413 			 * If we were asked to spawn a process into a new persona,
4414 			 * do the credential switch now (which may override the UID/GID
4415 			 * inherit done just above). It's important to do this switch
4416 			 * before image activation both for reasons stated above, and
4417 			 * to ensure that the new persona has access to the image/file
4418 			 * being executed.
4419 			 */
4420 			error = spawn_persona_adopt(p, imgp->ip_px_persona);
4421 			if (error != 0) {
4422 				goto bad;
4423 			}
4424 		}
4425 #endif /* CONFIG_PERSONAS */
4426 #if !SECURE_KERNEL
4427 		/*
4428 		 * Disable ASLR for the spawned process.
4429 		 *
4430 		 * But only do so if we are not embedded + RELEASE.
4431 		 * While embedded allows for a boot-arg (-disable_aslr)
4432 		 * to deal with this (which itself is only honored on
4433 		 * DEVELOPMENT or DEBUG builds of xnu), it is often
4434 		 * useful or necessary to disable ASLR on a per-process
4435 		 * basis for unit testing and debugging.
4436 		 */
4437 		if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
4438 			OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
4439 		}
4440 #endif /* !SECURE_KERNEL */
4441 
4442 		/* Randomize high bits of ASLR slide */
4443 		if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
4444 			imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
4445 		}
4446 
4447 #if !SECURE_KERNEL
4448 		/*
4449 		 * Forcibly disallow execution from data pages for the spawned process
4450 		 * even if it would otherwise be permitted by the architecture default.
4451 		 */
4452 		if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
4453 			imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
4454 		}
4455 #endif /* !SECURE_KERNEL */
4456 
4457 #if     __has_feature(ptrauth_calls)
4458 		if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
4459 			imgp->ip_flags |= IMGPF_RESLIDE;
4460 		}
4461 #endif /* __has_feature(ptrauth_calls) */
4462 
4463 		if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
4464 		    POSIX_SPAWN_PROC_TYPE_DRIVER) {
4465 			imgp->ip_flags |= IMGPF_DRIVER;
4466 		}
4467 	}
4468 
4469 	/*
4470 	 * Disable ASLR during image activation.  This occurs either if the
4471 	 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
4472 	 * P_DISABLE_ASLR was inherited from the parent process.
4473 	 */
4474 	if (p->p_flag & P_DISABLE_ASLR) {
4475 		imgp->ip_flags |= IMGPF_DISABLE_ASLR;
4476 	}
4477 
4478 	/*
4479 	 * Clear transition flag so we won't hang if exec_activate_image() causes
4480 	 * an automount (and launchd does a proc sysctl to service it).
4481 	 *
4482 	 * <rdar://problem/6848672>, <rdar://problem/5959568>.
4483 	 */
4484 	proc_transend(p, 0);
4485 	proc_transit_set = 0;
4486 
4487 	if (!spawn_no_exec) {
4488 		/*
4489 		 * Clear the signal lock in case of exec, since
4490 		 * image activation uses psignal on child process.
4491 		 */
4492 		proc_signalend(p, 0);
4493 		proc_signal_set = 0;
4494 	}
4495 
4496 #if MAC_SPAWN   /* XXX */
4497 	if (uap->mac_p != USER_ADDR_NULL) {
4498 		error = mac_execve_enter(uap->mac_p, imgp);
4499 		if (error) {
4500 			goto bad;
4501 		}
4502 	}
4503 #endif
4504 
4505 
4506 	/*
4507 	 * Activate the image.
4508 	 * Warning: If activation failed after point of no return, it returns error
4509 	 * as 0 and pretends the call succeeded.
4510 	 */
4511 	error = exec_activate_image(imgp);
4512 #if defined(HAS_APPLE_PAC)
4513 	const uint8_t disable_user_jop = imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE;
4514 	ml_task_set_jop_pid_from_shared_region(new_task, disable_user_jop);
4515 	ml_task_set_disable_user_jop(new_task, disable_user_jop);
4516 	ml_thread_set_disable_user_jop(imgp->ip_new_thread, disable_user_jop);
4517 	ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4518 #endif
4519 
4520 	/*
4521 	 * If you've come here to add support for some new HW feature or some per-process or per-vmmap
4522 	 * or per-pmap flag that needs to be set before the process runs, or are in general lost, here
4523 	 * is some help. This summary was accurate as of Jul 2022. Use git log as needed. This comment
4524 	 * is here to prevent a recurrence of rdar://96307913
4525 	 *
4526 	 * In posix_spawn, following is what happens:
4527 	 * 1. Lots of prep and checking work
4528 	 * 2. Image activation via exec_activate_image(). The new task will get a new pmap here
4529 	 * 3. More prep work. (YOU ARE HERE)
4530 	 * 4. exec_resettextvp() is called
4531 	 * 5. At this point it is safe to check entitlements and code signatures
4532 	 * 6. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4533 	 *    The new thread is allowed to run in kernel. It cannot yet get to userland
4534 	 * 7. More things done here. This is your chance to affect the task before it runs in
4535 	 *    userspace
4536 	 * 8. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4537 	 *     The new thread is allowed to run in userland
4538 	 */
4539 
4540 	if (error == 0 && !spawn_no_exec) {
4541 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
4542 		/* proc ref returned */
4543 		should_release_proc_ref = TRUE;
4544 	}
4545 
4546 	if (error == 0) {
4547 		/* process completed the exec, but may have failed after point of no return */
4548 		exec_done = TRUE;
4549 	}
4550 
4551 #if CONFIG_EXCLAVES
4552 	if (!error && task_conclave_id != NULL) {
4553 		kern_return_t kr;
4554 		kr = task_add_conclave(new_task, imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
4555 		    task_conclave_id);
4556 		if (kr != KERN_SUCCESS) {
4557 			error = EINVAL;
4558 			goto bad;
4559 		}
4560 	}
4561 #endif
4562 
4563 	if (!error && imgp->ip_px_sa != NULL) {
4564 		thread_t child_thread = imgp->ip_new_thread;
4565 		uthread_t child_uthread = get_bsdthread_info(child_thread);
4566 
4567 		/*
4568 		 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
4569 		 * activation, else when image activation fails (before the point of no
4570 		 * return) would leave the parent process in a modified state.
4571 		 */
4572 		if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
4573 			struct setpgid_args spga;
4574 			spga.pid = proc_getpid(p);
4575 			spga.pgid = px_sa.psa_pgroup;
4576 			/*
4577 			 * Effectively, call setpgid() system call; works
4578 			 * because there are no pointer arguments.
4579 			 */
4580 			if ((error = setpgid(p, &spga, ival)) != 0) {
4581 				goto bad_px_sa;
4582 			}
4583 		}
4584 
4585 		if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
4586 			error = setsid_internal(p);
4587 			if (error != 0) {
4588 				goto bad_px_sa;
4589 			}
4590 		}
4591 
4592 		/*
4593 		 * If we have a spawn attr, and it contains signal related flags,
4594 		 * the we need to process them in the "context" of the new child
4595 		 * process, so we have to process it following image activation,
4596 		 * prior to making the thread runnable in user space.  This is
4597 		 * necessitated by some signal information being per-thread rather
4598 		 * than per-process, and we don't have the new allocation in hand
4599 		 * until after the image is activated.
4600 		 */
4601 
4602 		/*
4603 		 * Mask a list of signals, instead of them being unmasked, if
4604 		 * they were unmasked in the parent; note that some signals
4605 		 * are not maskable.
4606 		 */
4607 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
4608 			child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
4609 		}
4610 		/*
4611 		 * Default a list of signals instead of ignoring them, if
4612 		 * they were ignored in the parent.  Note that we pass
4613 		 * spawn_no_exec to setsigvec() to indicate that we called
4614 		 * fork1() and therefore do not need to call proc_signalstart()
4615 		 * internally.
4616 		 */
4617 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
4618 			vec.sa_handler = SIG_DFL;
4619 			vec.sa_tramp = 0;
4620 			vec.sa_mask = 0;
4621 			vec.sa_flags = 0;
4622 			for (sig = 1; sig < NSIG; sig++) {
4623 				if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
4624 					error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
4625 				}
4626 			}
4627 		}
4628 
4629 		/*
4630 		 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
4631 		 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
4632 		 * limit.
4633 		 *
4634 		 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
4635 		 */
4636 		if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
4637 			/*
4638 			 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
4639 			 * an entitlement to configure the monitor a certain way seems silly, since
4640 			 * whomever is turning it on could just as easily choose not to do so.
4641 			 */
4642 			error = proc_set_task_ruse_cpu(proc_task(p),
4643 			    TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
4644 			    (uint8_t)px_sa.psa_cpumonitor_percent,
4645 			    px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
4646 			    0, TRUE);
4647 		}
4648 
4649 
4650 		if (px_pcred_info &&
4651 		    (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
4652 			/*
4653 			 * setlogin() must happen after setsid()
4654 			 */
4655 			setlogin_internal(p, px_pcred_info->pspci_login);
4656 		}
4657 
4658 bad_px_sa:
4659 		if (error != 0) {
4660 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
4661 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR, 0, 0);
4662 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR);
4663 		}
4664 	}
4665 
4666 bad:
4667 
4668 	if (error == 0) {
4669 		/* reset delay idle sleep status if set */
4670 #if CONFIG_DELAY_IDLE_SLEEP
4671 		if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
4672 			OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
4673 		}
4674 #endif /* CONFIG_DELAY_IDLE_SLEEP */
4675 		/* upon  successful spawn, re/set the proc control state */
4676 		if (imgp->ip_px_sa != NULL) {
4677 			switch (px_sa.psa_pcontrol) {
4678 			case POSIX_SPAWN_PCONTROL_THROTTLE:
4679 				p->p_pcaction = P_PCTHROTTLE;
4680 				break;
4681 			case POSIX_SPAWN_PCONTROL_SUSPEND:
4682 				p->p_pcaction = P_PCSUSP;
4683 				break;
4684 			case POSIX_SPAWN_PCONTROL_KILL:
4685 				p->p_pcaction = P_PCKILL;
4686 				break;
4687 			case POSIX_SPAWN_PCONTROL_NONE:
4688 			default:
4689 				p->p_pcaction = 0;
4690 				break;
4691 			}
4692 			;
4693 		}
4694 		exec_resettextvp(p, imgp);
4695 
4696 		/*
4697 		 * Enable new task IPC access if exec_activate_image() returned an
4698 		 * active task. (Checks active bit in ipc_task_enable() under lock).
4699 		 * Must enable after resettextvp so that task port policies are not evaluated
4700 		 * until the csblob in the textvp is accurately reflected.
4701 		 */
4702 		vm_map_setup(get_task_map(new_task), new_task);
4703 		ipc_task_enable(new_task);
4704 
4705 		/* Set task exception ports now that we can check entitlements */
4706 		if (imgp->ip_px_spa != NULL) {
4707 			error = exec_handle_exception_port_actions(imgp, &port_actions);
4708 		}
4709 
4710 #if CONFIG_MEMORYSTATUS
4711 		/* Set jetsam priority for DriverKit processes */
4712 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4713 			px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
4714 		}
4715 
4716 		/* Has jetsam attributes? */
4717 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
4718 			int32_t memlimit_active = px_sa.psa_memlimit_active;
4719 			int32_t memlimit_inactive = px_sa.psa_memlimit_inactive;
4720 
4721 			memstat_priority_options_t priority_options = MEMSTAT_PRIORITY_OPTIONS_NONE;
4722 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY)) {
4723 				priority_options |= MEMSTAT_PRIORITY_IS_EFFECTIVE;
4724 			}
4725 			memorystatus_set_priority(p, px_sa.psa_priority, 0,
4726 			    priority_options);
4727 
4728 			memlimit_options_t memlimit_options = MEMLIMIT_OPTIONS_NONE;
4729 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL)) {
4730 				memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
4731 			}
4732 			if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL)) {
4733 				memlimit_options |= MEMLIMIT_INACTIVE_FATAL;
4734 			}
4735 			if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
4736 				/*
4737 				 * With 2-level high-water-mark support,
4738 				 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no longer relevant,
4739 				 * as background limits are described via the inactive limit
4740 				 * slots. However, if the
4741 				 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in, we
4742 				 * attempt to mimic previous behavior by forcing the BG limit
4743 				 * data into the inactive/non-fatal mode and force the active
4744 				 * slots to hold system_wide/fatal mode.
4745 				 */
4746 				memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
4747 				memlimit_options &= ~MEMLIMIT_INACTIVE_FATAL;
4748 				memlimit_active = -1;
4749 			}
4750 			memorystatus_set_memlimits(p, memlimit_active, memlimit_inactive,
4751 			    memlimit_options);
4752 		}
4753 
4754 		/* Has jetsam relaunch behavior? */
4755 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
4756 			/*
4757 			 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
4758 			 * This data would be used by the jetsam subsystem to determine the position and protection
4759 			 * offered to this process on dirty -> clean transitions.
4760 			 */
4761 			int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
4762 			switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
4763 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
4764 				relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
4765 				break;
4766 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
4767 				relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
4768 				break;
4769 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
4770 				relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
4771 				break;
4772 			default:
4773 				break;
4774 			}
4775 			memorystatus_relaunch_flags_update(p, relaunch_flags);
4776 		}
4777 
4778 #endif /* CONFIG_MEMORYSTATUS */
4779 		if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
4780 			task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
4781 		}
4782 
4783 #if CONFIG_PROC_RESOURCE_LIMITS
4784 		if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
4785 			task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
4786 			    (uint32_t)px_sa.psa_port_hard_limit);
4787 		}
4788 
4789 		if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
4790 			proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
4791 			    (int)px_sa.psa_filedesc_hard_limit);
4792 		}
4793 		if (imgp->ip_px_sa != NULL && (px_sa.psa_kqworkloop_soft_limit > 0 || px_sa.psa_kqworkloop_hard_limit > 0)) {
4794 			proc_set_kqworkloop_limits(p, (int)px_sa.psa_kqworkloop_soft_limit,
4795 			    (int)px_sa.psa_kqworkloop_hard_limit);
4796 		}
4797 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
4798 	}
4799 
4800 
4801 	/*
4802 	 * If we successfully called fork1() or cloneproc, we always need
4803 	 * to do this. This is because we come back from that call with
4804 	 * signals blocked in the child, and we have to unblock them, for exec
4805 	 * case they are unblocked before activation, but for true spawn case
4806 	 * we want to wait until after we've performed any spawn actions.
4807 	 * This has to happen before process_signature(), which uses psignal.
4808 	 */
4809 	if (proc_transit_set) {
4810 		proc_transend(p, 0);
4811 	}
4812 
4813 	/*
4814 	 * Drop the signal lock on the child which was taken on our
4815 	 * behalf by forkproc()/cloneproc() to prevent signals being
4816 	 * received by the child in a partially constructed state.
4817 	 */
4818 	if (proc_signal_set) {
4819 		proc_signalend(p, 0);
4820 	}
4821 
4822 	if (error == 0) {
4823 		/*
4824 		 * We need to initialize the bank context behind the protection of
4825 		 * the proc_trans lock to prevent a race with exit. We can't do this during
4826 		 * exec_activate_image because task_bank_init checks entitlements that
4827 		 * aren't loaded until subsequent calls (including exec_resettextvp).
4828 		 */
4829 		error = proc_transstart(p, 0, 0);
4830 
4831 		if (error == 0) {
4832 			task_bank_init(new_task);
4833 			proc_transend(p, 0);
4834 		}
4835 
4836 #if __arm64__
4837 		proc_footprint_entitlement_hacks(p, new_task);
4838 #endif /* __arm64__ */
4839 
4840 #if XNU_TARGET_OS_OSX
4841 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4842 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4843 			vm_map_single_jit(get_task_map(new_task));
4844 		}
4845 #endif /* XNU_TARGET_OS_OSX */
4846 
4847 #if __has_feature(ptrauth_calls)
4848 		task_set_pac_exception_fatal_flag(new_task);
4849 #endif /* __has_feature(ptrauth_calls) */
4850 		task_set_jit_flags(new_task);
4851 	}
4852 
4853 	/* Inherit task role from old task to new task for exec */
4854 	if (error == 0 && !spawn_no_exec) {
4855 		proc_inherit_task_role(new_task, old_task);
4856 	}
4857 
4858 #if CONFIG_ARCADE
4859 	if (error == 0) {
4860 		/*
4861 		 * Check to see if we need to trigger an arcade upcall AST now
4862 		 * that the vnode has been reset on the task.
4863 		 */
4864 		arcade_prepare(new_task, imgp->ip_new_thread);
4865 	}
4866 #endif /* CONFIG_ARCADE */
4867 
4868 	if (error == 0) {
4869 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
4870 	}
4871 
4872 	/* Clear the initial wait on the thread before handling spawn policy */
4873 	if (imgp && imgp->ip_new_thread) {
4874 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4875 	}
4876 
4877 	/*
4878 	 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4879 	 * and bind any portwatch ports to the new task.
4880 	 * This must be done after the exec so that the child's thread is ready,
4881 	 * and after the in transit state has been released, because priority is
4882 	 * dropped here so we need to be prepared for a potentially long preemption interval
4883 	 *
4884 	 * TODO: Consider splitting this up into separate phases
4885 	 */
4886 	if (error == 0 && imgp->ip_px_sa != NULL) {
4887 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4888 
4889 		error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4890 		    psa->psa_darwin_role, &port_actions);
4891 	}
4892 
4893 	/* Transfer the turnstile watchport boost to new task if in exec */
4894 	if (error == 0 && !spawn_no_exec) {
4895 		task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4896 	}
4897 
4898 	if (error == 0 && imgp->ip_px_sa != NULL) {
4899 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4900 
4901 		if (psa->psa_no_smt) {
4902 			task_set_no_smt(new_task);
4903 		}
4904 		if (psa->psa_tecs) {
4905 			task_set_tecs(new_task);
4906 		}
4907 	}
4908 
4909 	if (error == 0 && imgp->ip_px_sa != NULL) {
4910 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4911 
4912 		if (psa->psa_options & PSA_OPTION_DATALESS_IOPOLICY) {
4913 			struct _iopol_param_t iop_param = {
4914 				.iop_scope = IOPOL_SCOPE_PROCESS,
4915 				.iop_iotype = IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES,
4916 				.iop_policy = psa->psa_dataless_iopolicy,
4917 			};
4918 			error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_SET, iop_param.iop_scope,
4919 			    iop_param.iop_policy, &iop_param);
4920 		}
4921 	}
4922 
4923 	if (error == 0) {
4924 		/* Apply the main thread qos */
4925 		thread_t main_thread = imgp->ip_new_thread;
4926 		task_set_main_thread_qos(new_task, main_thread);
4927 	}
4928 
4929 	/*
4930 	 * Release any ports we kept around for binding to the new task
4931 	 * We need to release the rights even if the posix_spawn has failed.
4932 	 */
4933 	if (imgp->ip_px_spa != NULL) {
4934 		exec_port_actions_destroy(&port_actions);
4935 	}
4936 
4937 	/*
4938 	 * We have to delay operations which might throw a signal until after
4939 	 * the signals have been unblocked; however, we want that to happen
4940 	 * after exec_resettextvp() so that the textvp is correct when they
4941 	 * fire.
4942 	 */
4943 	if (error == 0) {
4944 		error = process_signature(p, imgp);
4945 
4946 		/*
4947 		 * Pay for our earlier safety; deliver the delayed signals from
4948 		 * the incomplete spawn process now that it's complete.
4949 		 */
4950 		if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4951 			psignal_vfork(p, proc_task(p), imgp->ip_new_thread, SIGTRAP);
4952 		}
4953 
4954 		if (error == 0 && !spawn_no_exec) {
4955 			KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4956 			    proc_getpid(p));
4957 		}
4958 	}
4959 
4960 	if (spawn_no_exec) {
4961 		/* flag the 'fork' has occurred */
4962 		proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4963 	}
4964 
4965 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
4966 	if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4967 		proc_knote(p, NOTE_EXEC);
4968 	}
4969 
4970 	if (imgp != NULL) {
4971 		uthread_set_exec_data(current_uthread(), NULL);
4972 		if (imgp->ip_vp) {
4973 			vnode_put(imgp->ip_vp);
4974 		}
4975 		if (imgp->ip_scriptvp) {
4976 			vnode_put(imgp->ip_scriptvp);
4977 		}
4978 		if (imgp->ip_strings) {
4979 			execargs_free(imgp);
4980 		}
4981 		if (imgp->ip_free_map) {
4982 			/* Free the map after dropping iocount on vnode to avoid deadlock */
4983 			vm_map_deallocate(imgp->ip_free_map);
4984 		}
4985 		kfree_data(imgp->ip_px_sfa,
4986 		    px_args.file_actions_size);
4987 		kfree_data(imgp->ip_px_spa,
4988 		    px_args.port_actions_size);
4989 #if CONFIG_PERSONAS
4990 		kfree_data(imgp->ip_px_persona,
4991 		    px_args.persona_info_size);
4992 #endif
4993 		kfree_data(imgp->ip_px_pcred_info,
4994 		    px_args.posix_cred_info_size);
4995 
4996 		if (subsystem_root_path != NULL) {
4997 			zfree(ZV_NAMEI, subsystem_root_path);
4998 		}
4999 #if CONFIG_MACF
5000 		struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
5001 		kfree_data(px_s->array, px_args.mac_extensions_size);
5002 		kfree_data(px_s->data, (vm_size_t)px_s->datalen);
5003 
5004 		if (imgp->ip_execlabelp) {
5005 			mac_cred_label_free(imgp->ip_execlabelp);
5006 			imgp->ip_execlabelp = NULL;
5007 		}
5008 		if (imgp->ip_scriptlabelp) {
5009 			mac_vnode_label_free(imgp->ip_scriptlabelp);
5010 			imgp->ip_scriptlabelp = NULL;
5011 		}
5012 		if (imgp->ip_cs_error != OS_REASON_NULL) {
5013 			os_reason_free(imgp->ip_cs_error);
5014 			imgp->ip_cs_error = OS_REASON_NULL;
5015 		}
5016 		if (imgp->ip_inherited_shared_region_id != NULL) {
5017 			kfree_data(imgp->ip_inherited_shared_region_id,
5018 			    strlen(imgp->ip_inherited_shared_region_id) + 1);
5019 			imgp->ip_inherited_shared_region_id = NULL;
5020 		}
5021 #endif
5022 	}
5023 
5024 #if CONFIG_DTRACE
5025 	if (spawn_no_exec) {
5026 		/*
5027 		 * In the original DTrace reference implementation,
5028 		 * posix_spawn() was a libc routine that just
5029 		 * did vfork(2) then exec(2).  Thus the proc::: probes
5030 		 * are very fork/exec oriented.  The details of this
5031 		 * in-kernel implementation of posix_spawn() is different
5032 		 * (while producing the same process-observable effects)
5033 		 * particularly w.r.t. errors, and which thread/process
5034 		 * is constructing what on behalf of whom.
5035 		 */
5036 		if (error) {
5037 			DTRACE_PROC1(spawn__failure, int, error);
5038 		} else {
5039 			DTRACE_PROC(spawn__success);
5040 			/*
5041 			 * Some DTrace scripts, e.g. newproc.d in
5042 			 * /usr/bin, rely on the the 'exec-success'
5043 			 * probe being fired in the child after the
5044 			 * new process image has been constructed
5045 			 * in order to determine the associated pid.
5046 			 *
5047 			 * So, even though the parent built the image
5048 			 * here, for compatibility, mark the new thread
5049 			 * so 'exec-success' fires on it as it leaves
5050 			 * the kernel.
5051 			 */
5052 			dtrace_thread_didexec(imgp->ip_new_thread);
5053 		}
5054 	} else {
5055 		if (error) {
5056 			DTRACE_PROC1(exec__failure, int, error);
5057 		} else {
5058 			dtrace_thread_didexec(imgp->ip_new_thread);
5059 		}
5060 	}
5061 
5062 	if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5063 		(*dtrace_proc_waitfor_hook)(p);
5064 	}
5065 #endif
5066 
5067 #if CONFIG_AUDIT
5068 	if (!error && AUDIT_ENABLED() && p) {
5069 		/* Add the CDHash of the new process to the audit record */
5070 		uint8_t *cdhash = cs_get_cdhash(p);
5071 		if (cdhash) {
5072 			AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5073 		}
5074 	}
5075 #endif
5076 
5077 	/* terminate the new task if exec failed  */
5078 	if (new_task != NULL && task_is_exec_copy(new_task)) {
5079 		task_terminate_internal(new_task);
5080 	}
5081 
5082 	if (exec_failure_reason && !spawn_no_exec) {
5083 		psignal_with_reason(p, SIGKILL, exec_failure_reason);
5084 		exec_failure_reason = NULL;
5085 	}
5086 
5087 	/* Return to both the parent and the child? */
5088 	if (imgp != NULL && spawn_no_exec) {
5089 		/*
5090 		 * If the parent wants the pid, copy it out
5091 		 */
5092 		if (error == 0 && pid != USER_ADDR_NULL) {
5093 			_Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
5094 			bool aligned = (pid & 3) == 0;
5095 			if (aligned) {
5096 				(void)copyout_atomic32(proc_getpid(p), pid);
5097 			} else {
5098 				(void)suword(pid, proc_getpid(p));
5099 			}
5100 		}
5101 		retval[0] = error;
5102 
5103 		/*
5104 		 * If we had an error, perform an internal reap ; this is
5105 		 * entirely safe, as we have a real process backing us.
5106 		 */
5107 		if (error) {
5108 			proc_list_lock();
5109 			p->p_listflag |= P_LIST_DEADPARENT;
5110 			proc_list_unlock();
5111 			proc_lock(p);
5112 			/* make sure no one else has killed it off... */
5113 			if (p->p_stat != SZOMB && p->exit_thread == NULL) {
5114 				p->exit_thread = current_thread();
5115 				p->p_posix_spawn_failed = true;
5116 				proc_unlock(p);
5117 				exit1(p, 1, (int *)NULL);
5118 			} else {
5119 				/* someone is doing it for us; just skip it */
5120 				proc_unlock(p);
5121 			}
5122 		}
5123 	}
5124 
5125 	/*
5126 	 * Do not terminate the current task, if proc_exec_switch_task did not
5127 	 * switch the tasks, terminating the current task without the switch would
5128 	 * result in loosing the SIGKILL status.
5129 	 */
5130 	if (task_did_exec(old_task)) {
5131 		/* Terminate the current task, since exec will start in new task */
5132 		task_terminate_internal(old_task);
5133 	}
5134 
5135 	/* Release the thread ref returned by cloneproc/fork1 */
5136 	if (imgp != NULL && imgp->ip_new_thread) {
5137 		/* clear the exec complete flag if there is an error before point of no-return */
5138 		uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5139 		if (!spawn_no_exec && !exec_done && error != 0) {
5140 			clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5141 		}
5142 		/* wake up the new thread */
5143 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5144 		thread_deallocate(imgp->ip_new_thread);
5145 		imgp->ip_new_thread = NULL;
5146 	}
5147 
5148 	/* Release the ref returned by cloneproc/fork1 */
5149 	if (new_task) {
5150 		task_deallocate(new_task);
5151 		new_task = NULL;
5152 	}
5153 
5154 	if (should_release_proc_ref) {
5155 		proc_rele(p);
5156 	}
5157 
5158 	kfree_type(typeof(*__spawn_data), __spawn_data);
5159 
5160 	if (inherit != NULL) {
5161 		ipc_importance_release(inherit);
5162 	}
5163 
5164 #if CONFIG_EXCLAVES
5165 	if (task_conclave_id != NULL) {
5166 		kfree_data(task_conclave_id, MAXCONCLAVENAME);
5167 	}
5168 #endif
5169 
5170 	assert(spawn_no_exec || exec_failure_reason == NULL);
5171 	return error;
5172 }
5173 
5174 /*
5175  * proc_exec_switch_task
5176  *
5177  * Parameters:  old_proc		proc before exec
5178  *		new_proc		proc after exec
5179  *		old_task		task before exec
5180  *		new_task		task after exec
5181  *		imgp			image params
5182  *		inherit			resulting importance linkage
5183  *
5184  * Returns: proc.
5185  *
5186  * Note: The function will switch proc in pid hash from old proc to new proc.
5187  * The switch needs to happen after draining all proc refs and inside
5188  * a proc list lock. In the case of failure to switch the proc, which
5189  * might happen if the process received a SIGKILL or jetsam killed it,
5190  * it will make sure that the new tasks terminates. User proc ref returned
5191  * to caller.
5192  *
5193  * This function is called after point of no return, in the case
5194  * failure to switch, it will terminate the new task and swallow the
5195  * error and let the terminated process complete exec and die.
5196  */
5197 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)5198 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)
5199 {
5200 	boolean_t task_active;
5201 	boolean_t proc_active;
5202 	boolean_t thread_active;
5203 	boolean_t reparent_traced_child = FALSE;
5204 	thread_t old_thread = current_thread();
5205 	thread_t new_thread = imgp->ip_new_thread;
5206 
5207 	thread_set_exec_promotion(old_thread);
5208 	old_proc = proc_refdrain_will_exec(old_proc);
5209 
5210 	new_proc = proc_refdrain_will_exec(new_proc);
5211 	/* extra proc ref returned to the caller */
5212 
5213 	assert(get_threadtask(new_thread) == new_task);
5214 	task_active = task_is_active(new_task);
5215 	proc_active = !(old_proc->p_lflag & P_LEXIT);
5216 
5217 	/* Check if the current thread is not aborted due to SIGKILL */
5218 	thread_active = thread_is_active(old_thread);
5219 
5220 	/*
5221 	 * Do not switch the proc if the new task or proc is already terminated
5222 	 * as a result of error in exec past point of no return
5223 	 */
5224 	if (proc_active && task_active && thread_active) {
5225 		uthread_t new_uthread = get_bsdthread_info(new_thread);
5226 		uthread_t old_uthread = current_uthread();
5227 
5228 		/* Clear dispatchqueue and workloop ast offset */
5229 		new_proc->p_dispatchqueue_offset = 0;
5230 		new_proc->p_dispatchqueue_serialno_offset = 0;
5231 		new_proc->p_dispatchqueue_label_offset = 0;
5232 		new_proc->p_return_to_kernel_offset = 0;
5233 		new_proc->p_pthread_wq_quantum_offset = 0;
5234 
5235 		/* If old_proc is session leader, change the leader to new proc */
5236 		session_replace_leader(old_proc, new_proc);
5237 
5238 		proc_lock(old_proc);
5239 
5240 		/* Copy the signal state, dtrace state and set bsd ast on new thread */
5241 		act_set_astbsd(new_thread);
5242 		new_uthread->uu_siglist |= old_uthread->uu_siglist;
5243 		new_uthread->uu_siglist |= old_proc->p_siglist;
5244 		new_uthread->uu_sigwait = old_uthread->uu_sigwait;
5245 		new_uthread->uu_sigmask = old_uthread->uu_sigmask;
5246 		new_uthread->uu_oldmask = old_uthread->uu_oldmask;
5247 		new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
5248 #if CONFIG_DTRACE
5249 		new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
5250 		new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
5251 		new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
5252 		assert(new_uthread->t_dtrace_scratch == NULL);
5253 		new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
5254 
5255 		old_uthread->t_dtrace_sig = 0;
5256 		old_uthread->t_dtrace_stop = 0;
5257 		old_uthread->t_dtrace_resumepid = 0;
5258 		old_uthread->t_dtrace_scratch = NULL;
5259 #endif
5260 
5261 #if CONFIG_PROC_UDATA_STORAGE
5262 		new_proc->p_user_data = old_proc->p_user_data;
5263 #endif /* CONFIG_PROC_UDATA_STORAGE */
5264 
5265 		/* Copy the resource accounting info */
5266 		thread_copy_resource_info(new_thread, current_thread());
5267 
5268 		/* Clear the exit reason and signal state on old thread */
5269 		old_uthread->uu_exit_reason = NULL;
5270 		old_uthread->uu_siglist = 0;
5271 
5272 		task_set_did_exec_flag(old_task);
5273 		task_clear_exec_copy_flag(new_task);
5274 
5275 		task_copy_fields_for_exec(new_task, old_task);
5276 
5277 		/*
5278 		 * Need to transfer pending watch port boosts to the new task
5279 		 * while still making sure that the old task remains in the
5280 		 * importance linkage. Create an importance linkage from old task
5281 		 * to new task, then switch the task importance base of old task
5282 		 * and new task. After the switch the port watch boost will be
5283 		 * boosting the new task and new task will be donating importance
5284 		 * to old task.
5285 		 */
5286 		*inherit = ipc_importance_exec_switch_task(old_task, new_task);
5287 
5288 		/* Transfer parent's ptrace state to child */
5289 		new_proc->p_lflag &= ~(P_LTRACED | P_LSIGEXC | P_LNOATTACH);
5290 		new_proc->p_lflag |= (old_proc->p_lflag & (P_LTRACED | P_LSIGEXC | P_LNOATTACH));
5291 		new_proc->p_oppid = old_proc->p_oppid;
5292 
5293 		if (old_proc->p_pptr != new_proc->p_pptr) {
5294 			reparent_traced_child = TRUE;
5295 			new_proc->p_lflag |= P_LTRACE_WAIT;
5296 		}
5297 
5298 		proc_unlock(old_proc);
5299 
5300 		/* Update the list of proc knotes */
5301 		proc_transfer_knotes(old_proc, new_proc);
5302 
5303 		/* Update the proc interval timers */
5304 		proc_inherit_itimers(old_proc, new_proc);
5305 
5306 		proc_list_lock();
5307 
5308 		/* Insert the new proc in child list of parent proc */
5309 		p_reparentallchildren(old_proc, new_proc);
5310 
5311 		/* Switch proc in pid hash */
5312 		phash_replace_locked(old_proc, new_proc);
5313 
5314 		/* Transfer the shadow flag to old proc */
5315 		os_atomic_andnot(&new_proc->p_refcount, P_REF_SHADOW, relaxed);
5316 		os_atomic_or(&old_proc->p_refcount, P_REF_SHADOW, relaxed);
5317 
5318 		/* Change init proc if launchd exec */
5319 		if (old_proc == initproc) {
5320 			/* Take the ref on new proc after proc_refwake_did_exec */
5321 			initproc = new_proc;
5322 			/* Drop the proc ref on old proc */
5323 			proc_rele(old_proc);
5324 		}
5325 
5326 		proc_list_unlock();
5327 #if CONFIG_EXCLAVES
5328 		if (task_inherit_conclave(old_task, new_task, imgp->ip_vp,
5329 		    (int64_t)imgp->ip_arch_offset) != KERN_SUCCESS) {
5330 			task_terminate_internal(new_task);
5331 		}
5332 #endif
5333 	} else {
5334 		task_terminate_internal(new_task);
5335 	}
5336 
5337 	proc_refwake_did_exec(new_proc);
5338 	proc_refwake_did_exec(old_proc);
5339 
5340 	/* Take a ref on initproc if it changed */
5341 	if (new_proc == initproc) {
5342 		initproc = proc_ref(new_proc, false);
5343 		assert(initproc != PROC_NULL);
5344 	}
5345 
5346 	thread_clear_exec_promotion(old_thread);
5347 	proc_rele(old_proc);
5348 
5349 	if (reparent_traced_child) {
5350 		proc_t pp = proc_parent(old_proc);
5351 		assert(pp != PROC_NULL);
5352 
5353 		proc_reparentlocked(new_proc, pp, 1, 0);
5354 		proc_rele(pp);
5355 
5356 		proc_lock(new_proc);
5357 		new_proc->p_lflag &= ~P_LTRACE_WAIT;
5358 		proc_unlock(new_proc);
5359 	}
5360 
5361 	return new_proc;
5362 }
5363 
5364 /*
5365  * execve
5366  *
5367  * Parameters:	uap->fname		File name to exec
5368  *		uap->argp		Argument list
5369  *		uap->envp		Environment list
5370  *
5371  * Returns:	0			Success
5372  *	__mac_execve:EINVAL		Invalid argument
5373  *	__mac_execve:ENOTSUP		Invalid argument
5374  *	__mac_execve:EACCES		Permission denied
5375  *	__mac_execve:EINTR		Interrupted function
5376  *	__mac_execve:ENOMEM		Not enough space
5377  *	__mac_execve:EFAULT		Bad address
5378  *	__mac_execve:ENAMETOOLONG	Filename too long
5379  *	__mac_execve:ENOEXEC		Executable file format error
5380  *	__mac_execve:ETXTBSY		Text file busy [misuse of error code]
5381  *	__mac_execve:???
5382  *
5383  * TODO:	Dynamic linker header address on stack is copied via suword()
5384  */
5385 /* ARGSUSED */
5386 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)5387 execve(proc_t p, struct execve_args *uap, int32_t *retval)
5388 {
5389 	struct __mac_execve_args muap;
5390 	int err;
5391 
5392 	memoryshot(DBG_VM_EXECVE, DBG_FUNC_NONE);
5393 
5394 	muap.fname = uap->fname;
5395 	muap.argp = uap->argp;
5396 	muap.envp = uap->envp;
5397 	muap.mac_p = USER_ADDR_NULL;
5398 	err = __mac_execve(p, &muap, retval);
5399 
5400 	return err;
5401 }
5402 
5403 /*
5404  * __mac_execve
5405  *
5406  * Parameters:	uap->fname		File name to exec
5407  *		uap->argp		Argument list
5408  *		uap->envp		Environment list
5409  *		uap->mac_p		MAC label supplied by caller
5410  *
5411  * Returns:	0			Success
5412  *		EINVAL			Invalid argument
5413  *		ENOTSUP			Not supported
5414  *		ENOEXEC			Executable file format error
5415  *	exec_activate_image:EINVAL	Invalid argument
5416  *	exec_activate_image:EACCES	Permission denied
5417  *	exec_activate_image:EINTR	Interrupted function
5418  *	exec_activate_image:ENOMEM	Not enough space
5419  *	exec_activate_image:EFAULT	Bad address
5420  *	exec_activate_image:ENAMETOOLONG	Filename too long
5421  *	exec_activate_image:ENOEXEC	Executable file format error
5422  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
5423  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
5424  *	exec_activate_image:???
5425  *	mac_execve_enter:???
5426  *
5427  * TODO:	Dynamic linker header address on stack is copied via suword()
5428  */
5429 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)5430 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
5431 {
5432 	struct image_params *imgp = NULL;
5433 	struct vnode_attr *vap = NULL;
5434 	struct vnode_attr *origvap = NULL;
5435 	int error;
5436 	int is_64 = IS_64BIT_PROCESS(p);
5437 	struct vfs_context context;
5438 	struct uthread  *uthread = NULL;
5439 	task_t old_task = current_task();
5440 	task_t new_task = NULL;
5441 	boolean_t should_release_proc_ref = FALSE;
5442 	boolean_t exec_done = FALSE;
5443 	void *inherit = NULL;
5444 	struct {
5445 		struct image_params imgp;
5446 		struct vnode_attr va;
5447 		struct vnode_attr origva;
5448 	} *__execve_data;
5449 
5450 	/* Allocate a big chunk for locals instead of using stack since these
5451 	 * structures are pretty big.
5452 	 */
5453 	__execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
5454 	if (__execve_data == NULL) {
5455 		error = ENOMEM;
5456 		goto exit_with_error;
5457 	}
5458 	imgp = &__execve_data->imgp;
5459 	vap = &__execve_data->va;
5460 	origvap = &__execve_data->origva;
5461 
5462 	/* Initialize the common data in the image_params structure */
5463 	imgp->ip_user_fname = uap->fname;
5464 	imgp->ip_user_argv = uap->argp;
5465 	imgp->ip_user_envv = uap->envp;
5466 	imgp->ip_vattr = vap;
5467 	imgp->ip_origvattr = origvap;
5468 	imgp->ip_vfs_context = &context;
5469 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
5470 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
5471 	imgp->ip_mac_return = 0;
5472 	imgp->ip_cs_error = OS_REASON_NULL;
5473 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
5474 	imgp->ip_subsystem_root_path = NULL;
5475 	uthread_set_exec_data(current_uthread(), imgp);
5476 
5477 #if CONFIG_MACF
5478 	if (uap->mac_p != USER_ADDR_NULL) {
5479 		error = mac_execve_enter(uap->mac_p, imgp);
5480 		if (error) {
5481 			goto exit_with_error;
5482 		}
5483 	}
5484 #endif
5485 	uthread = current_uthread();
5486 	{
5487 		imgp->ip_flags |= IMGPF_EXEC;
5488 
5489 		/* Adjust the user proc count */
5490 		(void)chgproccnt(kauth_getruid(), 1);
5491 		/*
5492 		 * For execve case, create a new proc, task and thread
5493 		 * but don't make the proc visible to userland. After
5494 		 * image activation, the new proc would take place of
5495 		 * the old proc in pid hash and other lists that make
5496 		 * the proc visible to the system.
5497 		 */
5498 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
5499 		/* task and thread ref returned by cloneproc */
5500 		if (imgp->ip_new_thread == NULL) {
5501 			(void)chgproccnt(kauth_getruid(), -1);
5502 			error = ENOMEM;
5503 			goto exit_with_error;
5504 		}
5505 
5506 		new_task = get_threadtask(imgp->ip_new_thread);
5507 	}
5508 
5509 
5510 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
5511 
5512 	context.vc_thread = imgp->ip_new_thread;
5513 	context.vc_ucred = kauth_cred_proc_ref(p);      /* XXX must NOT be kauth_cred_get() */
5514 
5515 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
5516 
5517 	proc_transend(p, 0);
5518 	proc_signalend(p, 0);
5519 
5520 	/*
5521 	 * Activate the image.
5522 	 * Warning: If activation failed after point of no return, it returns error
5523 	 * as 0 and pretends the call succeeded.
5524 	 */
5525 	error = exec_activate_image(imgp);
5526 	/* thread and task ref returned for vfexec case */
5527 
5528 	if (imgp->ip_new_thread != NULL) {
5529 		/*
5530 		 * task reference might be returned by exec_activate_image
5531 		 * for vfexec.
5532 		 */
5533 		new_task = get_threadtask(imgp->ip_new_thread);
5534 #if defined(HAS_APPLE_PAC)
5535 		ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5536 		ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5537 #endif
5538 	}
5539 
5540 	if (!error) {
5541 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
5542 		/* proc ref returned */
5543 		should_release_proc_ref = TRUE;
5544 	}
5545 
5546 	kauth_cred_unref(&context.vc_ucred);
5547 
5548 	if (!error) {
5549 		exec_done = TRUE;
5550 		assert(imgp->ip_new_thread != NULL);
5551 
5552 		exec_resettextvp(p, imgp);
5553 		/*
5554 		 * Enable new task IPC access if exec_activate_image() returned an
5555 		 * active task. (Checks active bit in ipc_task_enable() under lock).
5556 		 * Must enable after resettextvp so that task port policies are not evaluated
5557 		 * until the csblob in the textvp is accurately reflected.
5558 		 */
5559 		vm_map_setup(get_task_map(new_task), new_task);
5560 		ipc_task_enable(new_task);
5561 		error = process_signature(p, imgp);
5562 	}
5563 
5564 #if defined(HAS_APPLE_PAC)
5565 	if (imgp->ip_new_thread && !error) {
5566 		ml_task_set_jop_pid_from_shared_region(new_task, imgp->ip_flags & IMGPF_NOJOP);
5567 		ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
5568 	}
5569 #endif /* defined(HAS_APPLE_PAC) */
5570 
5571 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
5572 	if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
5573 		proc_knote(p, NOTE_EXEC);
5574 	}
5575 
5576 	if (imgp->ip_vp != NULLVP) {
5577 		vnode_put(imgp->ip_vp);
5578 	}
5579 	if (imgp->ip_scriptvp != NULLVP) {
5580 		vnode_put(imgp->ip_scriptvp);
5581 	}
5582 	if (imgp->ip_free_map) {
5583 		/* Free the map after dropping iocount on vnode to avoid deadlock */
5584 		vm_map_deallocate(imgp->ip_free_map);
5585 	}
5586 	if (imgp->ip_strings) {
5587 		execargs_free(imgp);
5588 	}
5589 #if CONFIG_MACF
5590 	if (imgp->ip_execlabelp) {
5591 		mac_cred_label_free(imgp->ip_execlabelp);
5592 		imgp->ip_execlabelp = NULL;
5593 	}
5594 	if (imgp->ip_scriptlabelp) {
5595 		mac_vnode_label_free(imgp->ip_scriptlabelp);
5596 		imgp->ip_scriptlabelp = NULL;
5597 	}
5598 #endif
5599 	if (imgp->ip_cs_error != OS_REASON_NULL) {
5600 		os_reason_free(imgp->ip_cs_error);
5601 		imgp->ip_cs_error = OS_REASON_NULL;
5602 	}
5603 
5604 	if (!error) {
5605 		/*
5606 		 * We need to initialize the bank context behind the protection of
5607 		 * the proc_trans lock to prevent a race with exit. We can't do this during
5608 		 * exec_activate_image because task_bank_init checks entitlements that
5609 		 * aren't loaded until subsequent calls (including exec_resettextvp).
5610 		 */
5611 		error = proc_transstart(p, 0, 0);
5612 	}
5613 
5614 	if (!error) {
5615 		task_bank_init(new_task);
5616 		proc_transend(p, 0);
5617 
5618 		// Don't inherit crash behavior across exec, but preserve crash behavior from bootargs
5619 		p->p_crash_behavior = 0;
5620 		p->p_crash_behavior_deadline = 0;
5621 #if (DEVELOPMENT || DEBUG)
5622 		set_crash_behavior_from_bootarg(p);
5623 #endif
5624 
5625 #if __arm64__
5626 		proc_footprint_entitlement_hacks(p, new_task);
5627 #endif /* __arm64__ */
5628 
5629 #if XNU_TARGET_OS_OSX
5630 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
5631 			vm_map_single_jit(get_task_map(new_task));
5632 		}
5633 #endif /* XNU_TARGET_OS_OSX */
5634 
5635 		/* Sever any extant thread affinity */
5636 		thread_affinity_exec(current_thread());
5637 
5638 		/* Inherit task role from old task to new task for exec */
5639 		proc_inherit_task_role(new_task, old_task);
5640 
5641 		thread_t main_thread = imgp->ip_new_thread;
5642 
5643 		task_set_main_thread_qos(new_task, main_thread);
5644 
5645 #if __has_feature(ptrauth_calls)
5646 		task_set_pac_exception_fatal_flag(new_task);
5647 #endif /* __has_feature(ptrauth_calls) */
5648 		task_set_jit_flags(new_task);
5649 
5650 #if CONFIG_ARCADE
5651 		/*
5652 		 * Check to see if we need to trigger an arcade upcall AST now
5653 		 * that the vnode has been reset on the task.
5654 		 */
5655 		arcade_prepare(new_task, imgp->ip_new_thread);
5656 #endif /* CONFIG_ARCADE */
5657 
5658 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
5659 
5660 		if (vm_darkwake_mode == TRUE) {
5661 			/*
5662 			 * This process is being launched when the system
5663 			 * is in darkwake. So mark it specially. This will
5664 			 * cause all its pages to be entered in the background Q.
5665 			 */
5666 			task_set_darkwake_mode(new_task, vm_darkwake_mode);
5667 		}
5668 
5669 #if CONFIG_DTRACE
5670 		dtrace_thread_didexec(imgp->ip_new_thread);
5671 
5672 		if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5673 			(*dtrace_proc_waitfor_hook)(p);
5674 		}
5675 #endif
5676 
5677 #if CONFIG_AUDIT
5678 		if (!error && AUDIT_ENABLED() && p) {
5679 			/* Add the CDHash of the new process to the audit record */
5680 			uint8_t *cdhash = cs_get_cdhash(p);
5681 			if (cdhash) {
5682 				AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5683 			}
5684 		}
5685 #endif
5686 	} else {
5687 		DTRACE_PROC1(exec__failure, int, error);
5688 	}
5689 
5690 exit_with_error:
5691 
5692 	/* terminate the new task it if exec failed  */
5693 	if (new_task != NULL && task_is_exec_copy(new_task)) {
5694 		task_terminate_internal(new_task);
5695 	}
5696 
5697 	if (imgp != NULL) {
5698 		/* Clear the initial wait on the thread transferring watchports */
5699 		if (imgp->ip_new_thread) {
5700 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
5701 		}
5702 
5703 		/* Transfer the watchport boost to new task */
5704 		if (!error) {
5705 			task_transfer_turnstile_watchports(old_task,
5706 			    new_task, imgp->ip_new_thread);
5707 		}
5708 		/*
5709 		 * Do not terminate the current task, if proc_exec_switch_task did not
5710 		 * switch the tasks, terminating the current task without the switch would
5711 		 * result in loosing the SIGKILL status.
5712 		 */
5713 		if (task_did_exec(old_task)) {
5714 			/* Terminate the current task, since exec will start in new task */
5715 			task_terminate_internal(old_task);
5716 		}
5717 
5718 		/* Release the thread ref returned by cloneproc */
5719 		if (imgp->ip_new_thread) {
5720 			/* clear the exec complete flag if there is an error before point of no-return */
5721 			uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5722 			if (!exec_done && error != 0) {
5723 				clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5724 			}
5725 			/* wake up the new exec thread */
5726 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5727 			thread_deallocate(imgp->ip_new_thread);
5728 			imgp->ip_new_thread = NULL;
5729 		}
5730 	}
5731 
5732 	/* Release the ref returned by fork_create_child */
5733 	if (new_task) {
5734 		task_deallocate(new_task);
5735 		new_task = NULL;
5736 	}
5737 
5738 	if (should_release_proc_ref) {
5739 		proc_rele(p);
5740 	}
5741 
5742 	uthread_set_exec_data(current_uthread(), NULL);
5743 	kfree_type(typeof(*__execve_data), __execve_data);
5744 
5745 	if (inherit != NULL) {
5746 		ipc_importance_release(inherit);
5747 	}
5748 
5749 	return error;
5750 }
5751 
5752 
5753 /*
5754  * copyinptr
5755  *
5756  * Description:	Copy a pointer in from user space to a user_addr_t in kernel
5757  *		space, based on 32/64 bitness of the user space
5758  *
5759  * Parameters:	froma			User space address
5760  *		toptr			Address of kernel space user_addr_t
5761  *		ptr_size		4/8, based on 'froma' address space
5762  *
5763  * Returns:	0			Success
5764  *		EFAULT			Bad 'froma'
5765  *
5766  * Implicit returns:
5767  *		*ptr_size		Modified
5768  */
5769 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)5770 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
5771 {
5772 	int error;
5773 
5774 	if (ptr_size == 4) {
5775 		/* 64 bit value containing 32 bit address */
5776 		unsigned int i = 0;
5777 
5778 		error = copyin(froma, &i, 4);
5779 		*toptr = CAST_USER_ADDR_T(i);   /* SAFE */
5780 	} else {
5781 		error = copyin(froma, toptr, 8);
5782 	}
5783 	return error;
5784 }
5785 
5786 
5787 /*
5788  * copyoutptr
5789  *
5790  * Description:	Copy a pointer out from a user_addr_t in kernel space to
5791  *		user space, based on 32/64 bitness of the user space
5792  *
5793  * Parameters:	ua			User space address to copy to
5794  *		ptr			Address of kernel space user_addr_t
5795  *		ptr_size		4/8, based on 'ua' address space
5796  *
5797  * Returns:	0			Success
5798  *		EFAULT			Bad 'ua'
5799  *
5800  */
5801 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)5802 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
5803 {
5804 	int error;
5805 
5806 	if (ptr_size == 4) {
5807 		/* 64 bit value containing 32 bit address */
5808 		unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua);   /* SAFE */
5809 
5810 		error = copyout(&i, ptr, 4);
5811 	} else {
5812 		error = copyout(&ua, ptr, 8);
5813 	}
5814 	return error;
5815 }
5816 
5817 
5818 /*
5819  * exec_copyout_strings
5820  *
5821  * Copy out the strings segment to user space.  The strings segment is put
5822  * on a preinitialized stack frame.
5823  *
5824  * Parameters:	struct image_params *	the image parameter block
5825  *		int *			a pointer to the stack offset variable
5826  *
5827  * Returns:	0			Success
5828  *		!0			Faiure: errno
5829  *
5830  * Implicit returns:
5831  *		(*stackp)		The stack offset, modified
5832  *
5833  * Note:	The strings segment layout is backward, from the beginning
5834  *		of the top of the stack to consume the minimal amount of
5835  *		space possible; the returned stack pointer points to the
5836  *		end of the area consumed (stacks grow downward).
5837  *
5838  *		argc is an int; arg[i] are pointers; env[i] are pointers;
5839  *		the 0's are (void *)NULL's
5840  *
5841  * The stack frame layout is:
5842  *
5843  *      +-------------+ <- p->user_stack
5844  *      |     16b     |
5845  *      +-------------+
5846  *      | STRING AREA |
5847  *      |      :      |
5848  *      |      :      |
5849  *      |      :      |
5850  *      +- -- -- -- --+
5851  *      |  PATH AREA  |
5852  *      +-------------+
5853  *      |      0      |
5854  *      +-------------+
5855  *      |  applev[n]  |
5856  *      +-------------+
5857  *             :
5858  *             :
5859  *      +-------------+
5860  *      |  applev[1]  |
5861  *      +-------------+
5862  *      | exec_path / |
5863  *      |  applev[0]  |
5864  *      +-------------+
5865  *      |      0      |
5866  *      +-------------+
5867  *      |    env[n]   |
5868  *      +-------------+
5869  *             :
5870  *             :
5871  *      +-------------+
5872  *      |    env[0]   |
5873  *      +-------------+
5874  *      |      0      |
5875  *      +-------------+
5876  *      | arg[argc-1] |
5877  *      +-------------+
5878  *             :
5879  *             :
5880  *      +-------------+
5881  *      |    arg[0]   |
5882  *      +-------------+
5883  *      |     argc    |
5884  * sp-> +-------------+
5885  *
5886  * Although technically a part of the STRING AREA, we treat the PATH AREA as
5887  * a separate entity.  This allows us to align the beginning of the PATH AREA
5888  * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
5889  * which preceed it on the stack are properly aligned.
5890  */
5891 __attribute__((noinline))
5892 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)5893 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
5894 {
5895 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5896 	int     ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5897 	int     ptr_area_size;
5898 	void *ptr_buffer_start, *ptr_buffer;
5899 	size_t string_size;
5900 
5901 	user_addr_t     string_area;    /* *argv[], *env[] */
5902 	user_addr_t     ptr_area;       /* argv[], env[], applev[] */
5903 	user_addr_t argc_area;  /* argc */
5904 	user_addr_t     stack;
5905 	int error;
5906 
5907 	unsigned i;
5908 	struct copyout_desc {
5909 		char    *start_string;
5910 		int             count;
5911 #if CONFIG_DTRACE
5912 		user_addr_t     *dtrace_cookie;
5913 #endif
5914 		boolean_t       null_term;
5915 	} descriptors[] = {
5916 		{
5917 			.start_string = imgp->ip_startargv,
5918 			.count = imgp->ip_argc,
5919 #if CONFIG_DTRACE
5920 			.dtrace_cookie = &p->p_dtrace_argv,
5921 #endif
5922 			.null_term = TRUE
5923 		},
5924 		{
5925 			.start_string = imgp->ip_endargv,
5926 			.count = imgp->ip_envc,
5927 #if CONFIG_DTRACE
5928 			.dtrace_cookie = &p->p_dtrace_envp,
5929 #endif
5930 			.null_term = TRUE
5931 		},
5932 		{
5933 			.start_string = imgp->ip_strings,
5934 			.count = 1,
5935 #if CONFIG_DTRACE
5936 			.dtrace_cookie = NULL,
5937 #endif
5938 			.null_term = FALSE
5939 		},
5940 		{
5941 			.start_string = imgp->ip_endenvv,
5942 			.count = imgp->ip_applec - 1, /* exec_path handled above */
5943 #if CONFIG_DTRACE
5944 			.dtrace_cookie = NULL,
5945 #endif
5946 			.null_term = TRUE
5947 		}
5948 	};
5949 
5950 	stack = *stackp;
5951 
5952 	/*
5953 	 * All previous contributors to the string area
5954 	 * should have aligned their sub-area
5955 	 */
5956 	if (imgp->ip_strspace % ptr_size != 0) {
5957 		error = EINVAL;
5958 		goto bad;
5959 	}
5960 
5961 	/* Grow the stack down for the strings we've been building up */
5962 	string_size = imgp->ip_strendp - imgp->ip_strings;
5963 	stack -= string_size;
5964 	string_area = stack;
5965 
5966 	/*
5967 	 * Need room for one pointer for each string, plus
5968 	 * one for the NULLs terminating the argv, envv, and apple areas.
5969 	 */
5970 	ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5971 	stack -= ptr_area_size;
5972 	ptr_area = stack;
5973 
5974 	/* We'll construct all the pointer arrays in our string buffer,
5975 	 * which we already know is aligned properly, and ip_argspace
5976 	 * was used to verify we have enough space.
5977 	 */
5978 	ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5979 
5980 	/*
5981 	 * Need room for pointer-aligned argc slot.
5982 	 */
5983 	stack -= ptr_size;
5984 	argc_area = stack;
5985 
5986 	/*
5987 	 * Record the size of the arguments area so that sysctl_procargs()
5988 	 * can return the argument area without having to parse the arguments.
5989 	 */
5990 	proc_lock(p);
5991 	p->p_argc = imgp->ip_argc;
5992 	p->p_argslen = (int)(*stackp - string_area);
5993 	proc_unlock(p);
5994 
5995 	/* Return the initial stack address: the location of argc */
5996 	*stackp = stack;
5997 
5998 	/*
5999 	 * Copy out the entire strings area.
6000 	 */
6001 	error = copyout(imgp->ip_strings, string_area,
6002 	    string_size);
6003 	if (error) {
6004 		goto bad;
6005 	}
6006 
6007 	for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
6008 		char *cur_string = descriptors[i].start_string;
6009 		int j;
6010 
6011 #if CONFIG_DTRACE
6012 		if (descriptors[i].dtrace_cookie) {
6013 			proc_lock(p);
6014 			*descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
6015 			proc_unlock(p);
6016 		}
6017 #endif /* CONFIG_DTRACE */
6018 
6019 		/*
6020 		 * For each segment (argv, envv, applev), copy as many pointers as requested
6021 		 * to our pointer buffer.
6022 		 */
6023 		for (j = 0; j < descriptors[i].count; j++) {
6024 			user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
6025 
6026 			/* Copy out the pointer to the current string. Alignment has been verified  */
6027 			if (ptr_size == 8) {
6028 				*(uint64_t *)ptr_buffer = (uint64_t)cur_address;
6029 			} else {
6030 				*(uint32_t *)ptr_buffer = (uint32_t)cur_address;
6031 			}
6032 
6033 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
6034 			cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
6035 		}
6036 
6037 		if (descriptors[i].null_term) {
6038 			if (ptr_size == 8) {
6039 				*(uint64_t *)ptr_buffer = 0ULL;
6040 			} else {
6041 				*(uint32_t *)ptr_buffer = 0;
6042 			}
6043 
6044 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
6045 		}
6046 	}
6047 
6048 	/*
6049 	 * Copy out all our pointer arrays in bulk.
6050 	 */
6051 	error = copyout(ptr_buffer_start, ptr_area,
6052 	    ptr_area_size);
6053 	if (error) {
6054 		goto bad;
6055 	}
6056 
6057 	/* argc (int32, stored in a ptr_size area) */
6058 	error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
6059 	if (error) {
6060 		goto bad;
6061 	}
6062 
6063 bad:
6064 	return error;
6065 }
6066 
6067 
6068 /*
6069  * exec_extract_strings
6070  *
6071  * Copy arguments and environment from user space into work area; we may
6072  * have already copied some early arguments into the work area, and if
6073  * so, any arguments opied in are appended to those already there.
6074  * This function is the primary manipulator of ip_argspace, since
6075  * these are the arguments the client of execve(2) knows about. After
6076  * each argv[]/envv[] string is copied, we charge the string length
6077  * and argv[]/envv[] pointer slot to ip_argspace, so that we can
6078  * full preflight the arg list size.
6079  *
6080  * Parameters:	struct image_params *	the image parameter block
6081  *
6082  * Returns:	0			Success
6083  *		!0			Failure: errno
6084  *
6085  * Implicit returns;
6086  *		(imgp->ip_argc)		Count of arguments, updated
6087  *		(imgp->ip_envc)		Count of environment strings, updated
6088  *		(imgp->ip_argspace)	Count of remaining of NCARGS
6089  *		(imgp->ip_interp_buffer)	Interpreter and args (mutated in place)
6090  *
6091  *
6092  * Note:	The argument and environment vectors are user space pointers
6093  *		to arrays of user space pointers.
6094  */
6095 __attribute__((noinline))
6096 static int
exec_extract_strings(struct image_params * imgp)6097 exec_extract_strings(struct image_params *imgp)
6098 {
6099 	int error = 0;
6100 	int     ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
6101 	int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6102 	user_addr_t     argv = imgp->ip_user_argv;
6103 	user_addr_t     envv = imgp->ip_user_envv;
6104 
6105 	/*
6106 	 * Adjust space reserved for the path name by however much padding it
6107 	 * needs. Doing this here since we didn't know if this would be a 32-
6108 	 * or 64-bit process back in exec_save_path.
6109 	 */
6110 	while (imgp->ip_strspace % new_ptr_size != 0) {
6111 		*imgp->ip_strendp++ = '\0';
6112 		imgp->ip_strspace--;
6113 		/* imgp->ip_argspace--; not counted towards exec args total */
6114 	}
6115 
6116 	/*
6117 	 * From now on, we start attributing string space to ip_argspace
6118 	 */
6119 	imgp->ip_startargv = imgp->ip_strendp;
6120 	imgp->ip_argc = 0;
6121 
6122 	if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
6123 		user_addr_t     arg;
6124 		char *argstart, *ch;
6125 
6126 		/* First, the arguments in the "#!" string are tokenized and extracted. */
6127 		argstart = imgp->ip_interp_buffer;
6128 		while (argstart) {
6129 			ch = argstart;
6130 			while (*ch && !IS_WHITESPACE(*ch)) {
6131 				ch++;
6132 			}
6133 
6134 			if (*ch == '\0') {
6135 				/* last argument, no need to NUL-terminate */
6136 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
6137 				argstart = NULL;
6138 			} else {
6139 				/* NUL-terminate */
6140 				*ch = '\0';
6141 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
6142 
6143 				/*
6144 				 * Find the next string. We know spaces at the end of the string have already
6145 				 * been stripped.
6146 				 */
6147 				argstart = ch + 1;
6148 				while (IS_WHITESPACE(*argstart)) {
6149 					argstart++;
6150 				}
6151 			}
6152 
6153 			/* Error-check, regardless of whether this is the last interpreter arg or not */
6154 			if (error) {
6155 				goto bad;
6156 			}
6157 			if (imgp->ip_argspace < new_ptr_size) {
6158 				error = E2BIG;
6159 				goto bad;
6160 			}
6161 			imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6162 			imgp->ip_argc++;
6163 		}
6164 
6165 		if (argv != 0LL) {
6166 			/*
6167 			 * If we are running an interpreter, replace the av[0] that was
6168 			 * passed to execve() with the path name that was
6169 			 * passed to execve() for interpreters which do not use the PATH
6170 			 * to locate their script arguments.
6171 			 */
6172 			error = copyinptr(argv, &arg, ptr_size);
6173 			if (error) {
6174 				goto bad;
6175 			}
6176 			if (arg != 0LL) {
6177 				argv += ptr_size; /* consume without using */
6178 			}
6179 		}
6180 
6181 		if (imgp->ip_interp_sugid_fd != -1) {
6182 			char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
6183 			snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
6184 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
6185 		} else {
6186 			error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
6187 		}
6188 
6189 		if (error) {
6190 			goto bad;
6191 		}
6192 		if (imgp->ip_argspace < new_ptr_size) {
6193 			error = E2BIG;
6194 			goto bad;
6195 		}
6196 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6197 		imgp->ip_argc++;
6198 	}
6199 
6200 	while (argv != 0LL) {
6201 		user_addr_t     arg;
6202 
6203 		error = copyinptr(argv, &arg, ptr_size);
6204 		if (error) {
6205 			goto bad;
6206 		}
6207 
6208 		if (arg == 0LL) {
6209 			break;
6210 		}
6211 
6212 		argv += ptr_size;
6213 
6214 		/*
6215 		 * av[n...] = arg[n]
6216 		 */
6217 		error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
6218 		if (error) {
6219 			goto bad;
6220 		}
6221 		if (imgp->ip_argspace < new_ptr_size) {
6222 			error = E2BIG;
6223 			goto bad;
6224 		}
6225 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6226 		imgp->ip_argc++;
6227 	}
6228 
6229 	/* Save space for argv[] NULL terminator */
6230 	if (imgp->ip_argspace < new_ptr_size) {
6231 		error = E2BIG;
6232 		goto bad;
6233 	}
6234 	imgp->ip_argspace -= new_ptr_size;
6235 
6236 	/* Note where the args ends and env begins. */
6237 	imgp->ip_endargv = imgp->ip_strendp;
6238 	imgp->ip_envc = 0;
6239 
6240 	/* Now, get the environment */
6241 	while (envv != 0LL) {
6242 		user_addr_t     env;
6243 
6244 		error = copyinptr(envv, &env, ptr_size);
6245 		if (error) {
6246 			goto bad;
6247 		}
6248 
6249 		envv += ptr_size;
6250 		if (env == 0LL) {
6251 			break;
6252 		}
6253 		/*
6254 		 * av[n...] = env[n]
6255 		 */
6256 		error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
6257 		if (error) {
6258 			goto bad;
6259 		}
6260 		if (imgp->ip_argspace < new_ptr_size) {
6261 			error = E2BIG;
6262 			goto bad;
6263 		}
6264 		imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
6265 		imgp->ip_envc++;
6266 	}
6267 
6268 	/* Save space for envv[] NULL terminator */
6269 	if (imgp->ip_argspace < new_ptr_size) {
6270 		error = E2BIG;
6271 		goto bad;
6272 	}
6273 	imgp->ip_argspace -= new_ptr_size;
6274 
6275 	/* Align the tail of the combined argv+envv area */
6276 	while (imgp->ip_strspace % new_ptr_size != 0) {
6277 		if (imgp->ip_argspace < 1) {
6278 			error = E2BIG;
6279 			goto bad;
6280 		}
6281 		*imgp->ip_strendp++ = '\0';
6282 		imgp->ip_strspace--;
6283 		imgp->ip_argspace--;
6284 	}
6285 
6286 	/* Note where the envv ends and applev begins. */
6287 	imgp->ip_endenvv = imgp->ip_strendp;
6288 
6289 	/*
6290 	 * From now on, we are no longer charging argument
6291 	 * space to ip_argspace.
6292 	 */
6293 
6294 bad:
6295 	return error;
6296 }
6297 
6298 /*
6299  * Libc has an 8-element array set up for stack guard values.  It only fills
6300  * in one of those entries, and both gcc and llvm seem to use only a single
6301  * 8-byte guard.  Until somebody needs more than an 8-byte guard value, don't
6302  * do the work to construct them.
6303  */
6304 #define GUARD_VALUES 1
6305 #define GUARD_KEY "stack_guard="
6306 
6307 /*
6308  * System malloc needs some entropy when it is initialized.
6309  */
6310 #define ENTROPY_VALUES 2
6311 #define ENTROPY_KEY "malloc_entropy="
6312 
6313 /*
6314  * libplatform needs a random pointer-obfuscation value when it is initialized.
6315  */
6316 #define PTR_MUNGE_VALUES 1
6317 #define PTR_MUNGE_KEY "ptr_munge="
6318 
6319 /*
6320  * System malloc engages nanozone for UIAPP.
6321  */
6322 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
6323 
6324 /*
6325  * Used to pass experiment flags up to libmalloc.
6326  */
6327 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
6328 
6329 /*
6330  * Passes information about hardened runtime entitlements to libsystem/libmalloc
6331  */
6332 #define HARDENED_RUNTIME_KEY "HardenedRuntime="
6333 
6334 #define PFZ_KEY "pfz="
6335 extern user32_addr_t commpage_text32_location;
6336 extern user64_addr_t commpage_text64_location;
6337 
6338 extern uuid_string_t bootsessionuuid_string;
6339 static TUNABLE(uint32_t, exe_boothash_salt, "exe_boothash_salt", 0);
6340 
6341 __startup_func
6342 static void
exe_boothash_salt_generate(void)6343 exe_boothash_salt_generate(void)
6344 {
6345 	if (!PE_parse_boot_argn("exe_boothash_salt", NULL, 0)) {
6346 		read_random(&exe_boothash_salt, sizeof(exe_boothash_salt));
6347 	}
6348 }
6349 STARTUP(EARLY_BOOT, STARTUP_RANK_MIDDLE, exe_boothash_salt_generate);
6350 
6351 
6352 #define MAIN_STACK_VALUES 4
6353 #define MAIN_STACK_KEY "main_stack="
6354 
6355 #define FSID_KEY "executable_file="
6356 #define DYLD_FSID_KEY "dyld_file="
6357 #define CDHASH_KEY "executable_cdhash="
6358 #define DYLD_FLAGS_KEY "dyld_flags="
6359 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
6360 #define APP_BOOT_SESSION_KEY "executable_boothash="
6361 #if __has_feature(ptrauth_calls)
6362 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
6363 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
6364 #endif /* __has_feature(ptrauth_calls) */
6365 #define MAIN_TH_PORT_KEY "th_port="
6366 
6367 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
6368 
6369 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
6370 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
6371 
6372 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6373 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
6374 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6375 
6376 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)6377 exec_add_entropy_key(struct image_params *imgp,
6378     const char *key,
6379     int values,
6380     boolean_t embedNUL)
6381 {
6382 	const int limit = 8;
6383 	uint64_t entropy[limit];
6384 	char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
6385 	if (values > limit) {
6386 		values = limit;
6387 	}
6388 
6389 	read_random(entropy, sizeof(entropy[0]) * values);
6390 
6391 	if (embedNUL) {
6392 		entropy[0] &= ~(0xffull << 8);
6393 	}
6394 
6395 	int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
6396 	size_t remaining = sizeof(str) - len;
6397 	for (int i = 1; i < values && remaining > 0; ++i) {
6398 		size_t start = sizeof(str) - remaining;
6399 		len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
6400 		remaining -= len;
6401 	}
6402 
6403 	return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
6404 }
6405 
6406 /*
6407  * Build up the contents of the apple[] string vector
6408  */
6409 #if (DEVELOPMENT || DEBUG)
6410 extern uint64_t dyld_flags;
6411 #endif
6412 
6413 #if __has_feature(ptrauth_calls)
6414 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)6415 is_arm64e_running_as_arm64(const struct image_params *imgp)
6416 {
6417 	return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
6418 	       (imgp->ip_flags & IMGPF_NOJOP);
6419 }
6420 #endif /* __has_feature(ptrauth_calls) */
6421 
6422 _Atomic uint64_t libmalloc_experiment_factors = 0;
6423 
6424 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result)6425 exec_add_apple_strings(struct image_params *imgp,
6426     const load_result_t *load_result)
6427 {
6428 	int error;
6429 	int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6430 	thread_t new_thread;
6431 	ipc_port_t sright;
6432 	uint64_t local_experiment_factors = 0;
6433 
6434 	/* exec_save_path stored the first string */
6435 	imgp->ip_applec = 1;
6436 
6437 	/* adding the pfz string */
6438 	{
6439 		char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
6440 
6441 		if (img_ptr_size == 8) {
6442 			__assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
6443 			assert(ret < sizeof(pfz_string));
6444 		} else {
6445 			snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
6446 		}
6447 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
6448 		if (error) {
6449 			printf("Failed to add the pfz string with error %d\n", error);
6450 			goto bad;
6451 		}
6452 		imgp->ip_applec++;
6453 	}
6454 
6455 	/* adding the NANO_ENGAGE_KEY key */
6456 	if (imgp->ip_px_sa) {
6457 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6458 		int proc_flags = psa->psa_flags;
6459 
6460 		if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
6461 			const char *nano_string = NANO_ENGAGE_KEY;
6462 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
6463 			if (error) {
6464 				goto bad;
6465 			}
6466 			imgp->ip_applec++;
6467 		}
6468 	}
6469 
6470 	/*
6471 	 * Supply libc with a collection of random values to use when
6472 	 * implementing -fstack-protector.
6473 	 *
6474 	 * (The first random string always contains an embedded NUL so that
6475 	 * __stack_chk_guard also protects against C string vulnerabilities)
6476 	 */
6477 	error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
6478 	if (error) {
6479 		goto bad;
6480 	}
6481 	imgp->ip_applec++;
6482 
6483 	/*
6484 	 * Supply libc with entropy for system malloc.
6485 	 */
6486 	error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
6487 	if (error) {
6488 		goto bad;
6489 	}
6490 	imgp->ip_applec++;
6491 
6492 	/*
6493 	 * Supply libpthread & libplatform with a random value to use for pointer
6494 	 * obfuscation.
6495 	 */
6496 	error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
6497 	if (error) {
6498 		goto bad;
6499 	}
6500 	imgp->ip_applec++;
6501 
6502 	/*
6503 	 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
6504 	 * stack if it was allocated by the kernel.
6505 	 *
6506 	 * The guard page is not included in this stack size as libpthread
6507 	 * expects to add it back in after receiving this value.
6508 	 */
6509 	if (load_result->unixproc) {
6510 		char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
6511 		snprintf(stack_string, sizeof(stack_string),
6512 		    MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
6513 		    (uint64_t)load_result->user_stack,
6514 		    (uint64_t)load_result->user_stack_size,
6515 		    (uint64_t)load_result->user_stack_alloc,
6516 		    (uint64_t)load_result->user_stack_alloc_size);
6517 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
6518 		if (error) {
6519 			goto bad;
6520 		}
6521 		imgp->ip_applec++;
6522 	}
6523 
6524 	if (imgp->ip_vattr) {
6525 		uint64_t fsid    = vnode_get_va_fsid(imgp->ip_vattr);
6526 		uint64_t fsobjid = imgp->ip_vattr->va_fileid;
6527 
6528 		char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6529 		snprintf(fsid_string, sizeof(fsid_string),
6530 		    FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
6531 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6532 		if (error) {
6533 			goto bad;
6534 		}
6535 		imgp->ip_applec++;
6536 	}
6537 
6538 	if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
6539 		char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6540 		snprintf(fsid_string, sizeof(fsid_string),
6541 		    DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
6542 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6543 		if (error) {
6544 			goto bad;
6545 		}
6546 		imgp->ip_applec++;
6547 	}
6548 
6549 	uint8_t cdhash[SHA1_RESULTLEN];
6550 	int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash);
6551 	if (cdhash_errror == 0) {
6552 		char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
6553 		strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
6554 		char *p = hash_string + sizeof(CDHASH_KEY) - 1;
6555 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6556 			snprintf(p, 3, "%02x", (int) cdhash[i]);
6557 			p += 2;
6558 		}
6559 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
6560 		if (error) {
6561 			goto bad;
6562 		}
6563 		imgp->ip_applec++;
6564 
6565 		/* hash together cd-hash and boot-session-uuid */
6566 		uint8_t sha_digest[SHA256_DIGEST_LENGTH];
6567 		SHA256_CTX sha_ctx;
6568 		SHA256_Init(&sha_ctx);
6569 		SHA256_Update(&sha_ctx, &exe_boothash_salt, sizeof(exe_boothash_salt));
6570 		SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
6571 		SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
6572 		SHA256_Final(sha_digest, &sha_ctx);
6573 		char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
6574 		strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
6575 		char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
6576 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6577 			snprintf(s, 3, "%02x", (int) sha_digest[i]);
6578 			s += 2;
6579 		}
6580 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
6581 		if (error) {
6582 			goto bad;
6583 		}
6584 		imgp->ip_applec++;
6585 	}
6586 #if (DEVELOPMENT || DEBUG)
6587 	if (dyld_flags) {
6588 		char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
6589 		snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
6590 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
6591 		if (error) {
6592 			goto bad;
6593 		}
6594 		imgp->ip_applec++;
6595 	}
6596 #endif
6597 	if (imgp->ip_subsystem_root_path) {
6598 		size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
6599 		char subsystem_root_path_string[buffer_len];
6600 		int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
6601 
6602 		if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
6603 			error = ENAMETOOLONG;
6604 			goto bad;
6605 		}
6606 
6607 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
6608 		if (error) {
6609 			goto bad;
6610 		}
6611 
6612 		imgp->ip_applec++;
6613 	}
6614 #if __has_feature(ptrauth_calls)
6615 	if (is_arm64e_running_as_arm64(imgp)) {
6616 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
6617 		if (error) {
6618 			goto bad;
6619 		}
6620 
6621 		imgp->ip_applec++;
6622 	}
6623 #endif /* __has_feature(ptrauth_calls) */
6624 
6625 
6626 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
6627 	{
6628 		char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
6629 		strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
6630 		bool allowAll = bootarg_arm64e_preview_abi;
6631 		strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
6632 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
6633 		if (error) {
6634 			goto bad;
6635 		}
6636 
6637 		imgp->ip_applec++;
6638 	}
6639 #endif
6640 	/*
6641 	 * Add main thread mach port name
6642 	 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
6643 	 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
6644 	 * against libpthread.
6645 	 */
6646 	if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
6647 		thread_reference(new_thread);
6648 		sright = convert_thread_to_port_pinned(new_thread);
6649 		task_t new_task = get_threadtask(new_thread);
6650 		mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
6651 		char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
6652 		snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
6653 
6654 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
6655 		if (error) {
6656 			goto bad;
6657 		}
6658 		imgp->ip_applec++;
6659 	}
6660 
6661 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6662 	if (imgp->ip_px_sa != NULL) {
6663 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6664 		if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
6665 			const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
6666 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
6667 			if (error) {
6668 				goto bad;
6669 			}
6670 			imgp->ip_applec++;
6671 		}
6672 	}
6673 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6674 
6675 	/* adding the libmalloc experiment string */
6676 	local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
6677 	if (__improbable(local_experiment_factors != 0)) {
6678 		char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
6679 
6680 		snprintf(
6681 			libmalloc_experiment_factors_string,
6682 			sizeof(libmalloc_experiment_factors_string),
6683 			LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
6684 			local_experiment_factors);
6685 		error = exec_add_user_string(
6686 			imgp,
6687 			CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
6688 			UIO_SYSSPACE,
6689 			FALSE);
6690 		if (error) {
6691 			printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
6692 			goto bad;
6693 		}
6694 		imgp->ip_applec++;
6695 	}
6696 
6697 	if (imgp->ip_flags & IMGPF_HARDENED_HEAP) {
6698 		const char *hardened_heap_shims = "hardened_heap=1";
6699 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hardened_heap_shims), UIO_SYSSPACE, FALSE);
6700 		if (error) {
6701 			printf("Failed to add hardened heap string with error %d\n", error);
6702 			goto bad;
6703 		}
6704 
6705 		imgp->ip_applec++;
6706 	}
6707 
6708 
6709 	/* tell dyld that it can leverage hardware for its read-only/read-write trusted path */
6710 	if (imgp->ip_flags & IMGPF_HW_TPRO) {
6711 		const char *dyld_hw_tpro = "dyld_hw_tpro=1";
6712 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_hw_tpro), UIO_SYSSPACE, FALSE);
6713 		if (error) {
6714 			printf("Failed to add dyld hw tpro setting with error %d\n", error);
6715 			goto bad;
6716 		}
6717 
6718 		imgp->ip_applec++;
6719 
6720 	}
6721 
6722 	if (load_result->hardened_runtime_binary) {
6723 		const size_t HR_STRING_SIZE = sizeof(HARDENED_RUNTIME_KEY) + HR_FLAGS_NUM_NIBBLES + 2 + 1;
6724 		char hardened_runtime[HR_STRING_SIZE];
6725 		snprintf(hardened_runtime, HR_STRING_SIZE, HARDENED_RUNTIME_KEY"0x%x", load_result->hardened_runtime_binary);
6726 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hardened_runtime), UIO_SYSSPACE, FALSE);
6727 		if (error) {
6728 			printf("Failed to add hardened runtime flag with error %d\n", error);
6729 			goto bad;
6730 		}
6731 		imgp->ip_applec++;
6732 	}
6733 	/* Align the tail of the combined applev area */
6734 	while (imgp->ip_strspace % img_ptr_size != 0) {
6735 		*imgp->ip_strendp++ = '\0';
6736 		imgp->ip_strspace--;
6737 	}
6738 
6739 bad:
6740 	return error;
6741 }
6742 
6743 /*
6744  * exec_check_permissions
6745  *
6746  * Description:	Verify that the file that is being attempted to be executed
6747  *		is in fact allowed to be executed based on it POSIX file
6748  *		permissions and other access control criteria
6749  *
6750  * Parameters:	struct image_params *	the image parameter block
6751  *
6752  * Returns:	0			Success
6753  *		EACCES			Permission denied
6754  *		ENOEXEC			Executable file format error
6755  *		ETXTBSY			Text file busy [misuse of error code]
6756  *	vnode_getattr:???
6757  *	vnode_authorize:???
6758  */
6759 static int
exec_check_permissions(struct image_params * imgp)6760 exec_check_permissions(struct image_params *imgp)
6761 {
6762 	struct vnode *vp = imgp->ip_vp;
6763 	struct vnode_attr *vap = imgp->ip_vattr;
6764 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6765 	int error;
6766 	kauth_action_t action;
6767 
6768 	/* Only allow execution of regular files */
6769 	if (!vnode_isreg(vp)) {
6770 		return EACCES;
6771 	}
6772 
6773 	/* Get the file attributes that we will be using here and elsewhere */
6774 	VATTR_INIT(vap);
6775 	VATTR_WANTED(vap, va_uid);
6776 	VATTR_WANTED(vap, va_gid);
6777 	VATTR_WANTED(vap, va_mode);
6778 	VATTR_WANTED(vap, va_fsid);
6779 	VATTR_WANTED(vap, va_fsid64);
6780 	VATTR_WANTED(vap, va_fileid);
6781 	VATTR_WANTED(vap, va_data_size);
6782 	if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
6783 		return error;
6784 	}
6785 
6786 	/*
6787 	 * Ensure that at least one execute bit is on - otherwise root
6788 	 * will always succeed, and we don't want to happen unless the
6789 	 * file really is executable.
6790 	 */
6791 	if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
6792 		return EACCES;
6793 	}
6794 
6795 	/* Disallow zero length files */
6796 	if (vap->va_data_size == 0) {
6797 		return ENOEXEC;
6798 	}
6799 
6800 	imgp->ip_arch_offset = (user_size_t)0;
6801 #if __LP64__
6802 	imgp->ip_arch_size = vap->va_data_size;
6803 #else
6804 	if (vap->va_data_size > UINT32_MAX) {
6805 		return ENOEXEC;
6806 	}
6807 	imgp->ip_arch_size = (user_size_t)vap->va_data_size;
6808 #endif
6809 
6810 	/* Disable setuid-ness for traced programs or if MNT_NOSUID */
6811 	if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
6812 		vap->va_mode &= ~(VSUID | VSGID);
6813 	}
6814 
6815 	/*
6816 	 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
6817 	 * flags for setuid/setgid binaries.
6818 	 */
6819 	if (vap->va_mode & (VSUID | VSGID)) {
6820 		imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
6821 	}
6822 
6823 #if CONFIG_MACF
6824 	error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
6825 	if (error) {
6826 		return error;
6827 	}
6828 #endif
6829 
6830 	/* Check for execute permission */
6831 	action = KAUTH_VNODE_EXECUTE;
6832 	/* Traced images must also be readable */
6833 	if (p->p_lflag & P_LTRACED) {
6834 		action |= KAUTH_VNODE_READ_DATA;
6835 	}
6836 	if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
6837 		return error;
6838 	}
6839 
6840 #if 0
6841 	/* Don't let it run if anyone had it open for writing */
6842 	vnode_lock(vp);
6843 	if (vp->v_writecount) {
6844 		panic("going to return ETXTBSY %x", vp);
6845 		vnode_unlock(vp);
6846 		return ETXTBSY;
6847 	}
6848 	vnode_unlock(vp);
6849 #endif
6850 
6851 	/* XXX May want to indicate to underlying FS that vnode is open */
6852 
6853 	return error;
6854 }
6855 
6856 
6857 /*
6858  * exec_handle_sugid
6859  *
6860  * Initially clear the P_SUGID in the process flags; if an SUGID process is
6861  * exec'ing a non-SUGID image, then  this is the point of no return.
6862  *
6863  * If the image being activated is SUGID, then replace the credential with a
6864  * copy, disable tracing (unless the tracing process is root), reset the
6865  * mach task port to revoke it, set the P_SUGID bit,
6866  *
6867  * If the saved user and group ID will be changing, then make sure it happens
6868  * to a new credential, rather than a shared one.
6869  *
6870  * Set the security token (this is probably obsolete, given that the token
6871  * should not technically be separate from the credential itself).
6872  *
6873  * Parameters:	struct image_params *	the image parameter block
6874  *
6875  * Returns:	void			No failure indication
6876  *
6877  * Implicit returns:
6878  *		<process credential>	Potentially modified/replaced
6879  *		<task port>		Potentially revoked
6880  *		<process flags>		P_SUGID bit potentially modified
6881  *		<security token>	Potentially modified
6882  */
6883 __attribute__((noinline))
6884 static int
exec_handle_sugid(struct image_params * imgp)6885 exec_handle_sugid(struct image_params *imgp)
6886 {
6887 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
6888 	kauth_cred_t            cred = vfs_context_ucred(imgp->ip_vfs_context);
6889 	int                     i;
6890 	int                     leave_sugid_clear = 0;
6891 	int                     mac_reset_ipc = 0;
6892 	int                     error = 0;
6893 #if CONFIG_MACF
6894 	int                     mac_transition, disjoint_cred = 0;
6895 	int             label_update_return = 0;
6896 
6897 	/*
6898 	 * Determine whether a call to update the MAC label will result in the
6899 	 * credential changing.
6900 	 *
6901 	 * Note:	MAC policies which do not actually end up modifying
6902 	 *		the label subsequently are strongly encouraged to
6903 	 *		return 0 for this check, since a non-zero answer will
6904 	 *		slow down the exec fast path for normal binaries.
6905 	 */
6906 	mac_transition = mac_cred_check_label_update_execve(
6907 		imgp->ip_vfs_context,
6908 		imgp->ip_vp,
6909 		imgp->ip_arch_offset,
6910 		imgp->ip_scriptvp,
6911 		imgp->ip_scriptlabelp,
6912 		imgp->ip_execlabelp,
6913 		p,
6914 		&imgp->ip_px_smpx);
6915 #endif
6916 
6917 	OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
6918 
6919 	/*
6920 	 * Order of the following is important; group checks must go last,
6921 	 * as we use the success of the 'ismember' check combined with the
6922 	 * failure of the explicit match to indicate that we will be setting
6923 	 * the egid of the process even though the new process did not
6924 	 * require VSUID/VSGID bits in order for it to set the new group as
6925 	 * its egid.
6926 	 *
6927 	 * Note:	Technically, by this we are implying a call to
6928 	 *		setegid() in the new process, rather than implying
6929 	 *		it used its VSGID bit to set the effective group,
6930 	 *		even though there is no code in that process to make
6931 	 *		such a call.
6932 	 */
6933 	if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
6934 	    kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
6935 	    ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
6936 	    ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
6937 	    (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
6938 #if CONFIG_MACF
6939 /* label for MAC transition and neither VSUID nor VSGID */
6940 handle_mac_transition:
6941 #endif
6942 
6943 #if CONFIG_SETUID
6944 		/*
6945 		 * Replace the credential with a copy of itself if euid or
6946 		 * egid change.
6947 		 *
6948 		 * Note:	setuid binaries will automatically opt out of
6949 		 *		group resolver participation as a side effect
6950 		 *		of this operation.  This is an intentional
6951 		 *		part of the security model, which requires a
6952 		 *		participating credential be established by
6953 		 *		escalating privilege, setting up all other
6954 		 *		aspects of the credential including whether
6955 		 *		or not to participate in external group
6956 		 *		membership resolution, then dropping their
6957 		 *		effective privilege to that of the desired
6958 		 *		final credential state.
6959 		 *
6960 		 * Modifications to p_ucred must be guarded using the
6961 		 * proc's ucred lock. This prevents others from accessing
6962 		 * a garbage credential.
6963 		 */
6964 
6965 		if (imgp->ip_origvattr->va_mode & VSUID) {
6966 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6967 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6968 				return kauth_cred_model_setresuid(model,
6969 				KAUTH_UID_NONE,
6970 				imgp->ip_origvattr->va_uid,
6971 				imgp->ip_origvattr->va_uid,
6972 				KAUTH_UID_NONE);
6973 			});
6974 		}
6975 
6976 		if (imgp->ip_origvattr->va_mode & VSGID) {
6977 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6978 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6979 				return kauth_cred_model_setresgid(model,
6980 				KAUTH_GID_NONE,
6981 				imgp->ip_origvattr->va_gid,
6982 				imgp->ip_origvattr->va_gid);
6983 			});
6984 		}
6985 #endif /* CONFIG_SETUID */
6986 
6987 #if CONFIG_MACF
6988 		/*
6989 		 * If a policy has indicated that it will transition the label,
6990 		 * before making the call into the MAC policies, get a new
6991 		 * duplicate credential, so they can modify it without
6992 		 * modifying any others sharing it.
6993 		 */
6994 		if (mac_transition) {
6995 			/*
6996 			 * This hook may generate upcalls that require
6997 			 * importance donation from the kernel.
6998 			 * (23925818)
6999 			 */
7000 			thread_t thread = current_thread();
7001 			thread_enable_send_importance(thread, TRUE);
7002 			kauth_proc_label_update_execve(p,
7003 			    imgp->ip_vfs_context,
7004 			    imgp->ip_vp,
7005 			    imgp->ip_arch_offset,
7006 			    imgp->ip_scriptvp,
7007 			    imgp->ip_scriptlabelp,
7008 			    imgp->ip_execlabelp,
7009 			    &imgp->ip_csflags,
7010 			    &imgp->ip_px_smpx,
7011 			    &disjoint_cred,                     /* will be non zero if disjoint */
7012 			    &label_update_return);
7013 			thread_enable_send_importance(thread, FALSE);
7014 
7015 			if (disjoint_cred) {
7016 				/*
7017 				 * If updating the MAC label resulted in a
7018 				 * disjoint credential, flag that we need to
7019 				 * set the P_SUGID bit.  This protects
7020 				 * against debuggers being attached by an
7021 				 * insufficiently privileged process onto the
7022 				 * result of a transition to a more privileged
7023 				 * credential.
7024 				 */
7025 				leave_sugid_clear = 0;
7026 			}
7027 
7028 			imgp->ip_mac_return = label_update_return;
7029 		}
7030 
7031 		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);
7032 
7033 #endif  /* CONFIG_MACF */
7034 
7035 		/*
7036 		 * If 'leave_sugid_clear' is non-zero, then we passed the
7037 		 * VSUID and MACF checks, and successfully determined that
7038 		 * the previous cred was a member of the VSGID group, but
7039 		 * that it was not the default at the time of the execve,
7040 		 * and that the post-labelling credential was not disjoint.
7041 		 * So we don't set the P_SUGID or reset mach ports and fds
7042 		 * on the basis of simply running this code.
7043 		 */
7044 		if (mac_reset_ipc || !leave_sugid_clear) {
7045 			/*
7046 			 * Have mach reset the task and thread ports.
7047 			 * We don't want anyone who had the ports before
7048 			 * a setuid exec to be able to access/control the
7049 			 * task/thread after.
7050 			 */
7051 			ipc_task_reset((imgp->ip_new_thread != NULL) ?
7052 			    get_threadtask(imgp->ip_new_thread) : proc_task(p));
7053 			ipc_thread_reset((imgp->ip_new_thread != NULL) ?
7054 			    imgp->ip_new_thread : current_thread());
7055 		}
7056 
7057 		if (!leave_sugid_clear) {
7058 			/*
7059 			 * Flag the process as setuid.
7060 			 */
7061 			OSBitOrAtomic(P_SUGID, &p->p_flag);
7062 
7063 			/*
7064 			 * Radar 2261856; setuid security hole fix
7065 			 * XXX For setuid processes, attempt to ensure that
7066 			 * stdin, stdout, and stderr are already allocated.
7067 			 * We do not want userland to accidentally allocate
7068 			 * descriptors in this range which has implied meaning
7069 			 * to libc.
7070 			 */
7071 			for (i = 0; i < 3; i++) {
7072 				if (fp_get_noref_locked(p, i) != NULL) {
7073 					continue;
7074 				}
7075 
7076 				/*
7077 				 * Do the kernel equivalent of
7078 				 *
7079 				 *      if i == 0
7080 				 *              (void) open("/dev/null", O_RDONLY);
7081 				 *      else
7082 				 *              (void) open("/dev/null", O_WRONLY);
7083 				 */
7084 
7085 				struct fileproc *fp;
7086 				int indx;
7087 				int flag;
7088 				struct nameidata *ndp = NULL;
7089 
7090 				if (i == 0) {
7091 					flag = FREAD;
7092 				} else {
7093 					flag = FWRITE;
7094 				}
7095 
7096 				if ((error = falloc_exec(p, imgp->ip_vfs_context,
7097 				    &fp, &indx)) != 0) {
7098 					continue;
7099 				}
7100 
7101 				ndp = kalloc_type(struct nameidata,
7102 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
7103 
7104 				NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
7105 				    CAST_USER_ADDR_T("/dev/null"),
7106 				    imgp->ip_vfs_context);
7107 
7108 				if ((error = vn_open(ndp, flag, 0)) != 0) {
7109 					fp_free(p, indx, fp);
7110 					kfree_type(struct nameidata, ndp);
7111 					break;
7112 				}
7113 
7114 				struct fileglob *fg = fp->fp_glob;
7115 
7116 				fg->fg_flag = flag;
7117 				fg->fg_ops = &vnops;
7118 				fp_set_data(fp, ndp->ni_vp);
7119 
7120 				vnode_put(ndp->ni_vp);
7121 
7122 				proc_fdlock(p);
7123 				procfdtbl_releasefd(p, indx, NULL);
7124 				fp_drop(p, indx, fp, 1);
7125 				proc_fdunlock(p);
7126 
7127 				kfree_type(struct nameidata, ndp);
7128 			}
7129 		}
7130 	}
7131 #if CONFIG_MACF
7132 	else {
7133 		/*
7134 		 * We are here because we were told that the MAC label will
7135 		 * be transitioned, and the binary is not VSUID or VSGID; to
7136 		 * deal with this case, we could either duplicate a lot of
7137 		 * code, or we can indicate we want to default the P_SUGID
7138 		 * bit clear and jump back up.
7139 		 */
7140 		if (mac_transition) {
7141 			leave_sugid_clear = 1;
7142 			goto handle_mac_transition;
7143 		}
7144 	}
7145 
7146 #endif  /* CONFIG_MACF */
7147 
7148 	/* Update the process' identity version and set the security token.
7149 	 * Also, ensure we always see a modified identity version (rdar://129775819).
7150 	 */
7151 	int previous_pid_version = proc_get_ro(p)->p_idversion;
7152 	int new_pid_version;
7153 	do {
7154 		new_pid_version = OSIncrementAtomic(&nextpidversion);
7155 	} while (new_pid_version == previous_pid_version);
7156 	proc_setpidversion(p, new_pid_version);
7157 	task_set_uniqueid(proc_task(p));
7158 
7159 	/*
7160 	 * Implement the semantic where the effective user and group become
7161 	 * the saved user and group in exec'ed programs.
7162 	 */
7163 	kauth_cred_proc_update(p, PROC_SETTOKEN_ALWAYS,
7164 	    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
7165 		posix_cred_t pcred = posix_cred_get(model);
7166 
7167 		if (pcred->cr_svuid == pcred->cr_uid &&
7168 		pcred->cr_svgid == pcred->cr_gid) {
7169 		        return false;
7170 		}
7171 
7172 		pcred->cr_svuid = pcred->cr_uid;
7173 		pcred->cr_svgid = pcred->cr_gid;
7174 		return true;
7175 	});
7176 
7177 	return error;
7178 }
7179 
7180 
7181 /*
7182  * create_unix_stack
7183  *
7184  * Description:	Set the user stack address for the process to the provided
7185  *		address.  If a custom stack was not set as a result of the
7186  *		load process (i.e. as specified by the image file for the
7187  *		executable), then allocate the stack in the provided map and
7188  *		set up appropriate guard pages for enforcing administrative
7189  *		limits on stack growth, if they end up being needed.
7190  *
7191  * Parameters:	p			Process to set stack on
7192  *		load_result		Information from mach-o load commands
7193  *		map			Address map in which to allocate the new stack
7194  *
7195  * Returns:	KERN_SUCCESS		Stack successfully created
7196  *		!KERN_SUCCESS		Mach failure code
7197  */
7198 __attribute__((noinline))
7199 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)7200 create_unix_stack(vm_map_t map, load_result_t* load_result,
7201     proc_t p)
7202 {
7203 	mach_vm_size_t          size, prot_size;
7204 	mach_vm_offset_t        addr, prot_addr;
7205 	kern_return_t           kr;
7206 
7207 	mach_vm_address_t       user_stack = load_result->user_stack;
7208 
7209 	proc_lock(p);
7210 	p->user_stack = (uintptr_t)user_stack;
7211 	if (load_result->custom_stack) {
7212 		p->p_lflag |= P_LCUSTOM_STACK;
7213 	}
7214 	proc_unlock(p);
7215 	if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
7216 		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);
7217 	}
7218 
7219 	if (load_result->user_stack_alloc_size > 0) {
7220 		/*
7221 		 * Allocate enough space for the maximum stack size we
7222 		 * will ever authorize and an extra page to act as
7223 		 * a guard page for stack overflows. For default stacks,
7224 		 * vm_initial_limit_stack takes care of the extra guard page.
7225 		 * Otherwise we must allocate it ourselves.
7226 		 */
7227 		if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
7228 			return KERN_INVALID_ARGUMENT;
7229 		}
7230 		addr = vm_map_trunc_page(load_result->user_stack - size,
7231 		    vm_map_page_mask(map));
7232 		kr = mach_vm_allocate_kernel(map, &addr, size,
7233 		    VM_MAP_KERNEL_FLAGS_FIXED(.vm_tag = VM_MEMORY_STACK));
7234 		if (kr != KERN_SUCCESS) {
7235 			// Can't allocate at default location, try anywhere
7236 			addr = 0;
7237 			kr = mach_vm_allocate_kernel(map, &addr, size,
7238 			    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vm_tag = VM_MEMORY_STACK));
7239 			if (kr != KERN_SUCCESS) {
7240 				return kr;
7241 			}
7242 
7243 			user_stack = addr + size;
7244 			load_result->user_stack = (user_addr_t)user_stack;
7245 
7246 			proc_lock(p);
7247 			p->user_stack = (uintptr_t)user_stack;
7248 			proc_unlock(p);
7249 		}
7250 
7251 		load_result->user_stack_alloc = (user_addr_t)addr;
7252 
7253 		/*
7254 		 * And prevent access to what's above the current stack
7255 		 * size limit for this process.
7256 		 */
7257 		if (load_result->user_stack_size == 0) {
7258 			load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
7259 			prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
7260 		} else {
7261 			prot_size = PAGE_SIZE;
7262 		}
7263 
7264 		prot_addr = addr;
7265 		kr = mach_vm_protect(map,
7266 		    prot_addr,
7267 		    prot_size,
7268 		    FALSE,
7269 		    VM_PROT_NONE);
7270 		if (kr != KERN_SUCCESS) {
7271 			(void)mach_vm_deallocate(map, addr, size);
7272 			return kr;
7273 		}
7274 	}
7275 
7276 	return KERN_SUCCESS;
7277 }
7278 
7279 #include <sys/reboot.h>
7280 
7281 /*
7282  * load_init_program_at_path
7283  *
7284  * Description:	Load the "init" program; in most cases, this will be "launchd"
7285  *
7286  * Parameters:	p			Process to call execve() to create
7287  *					the "init" program
7288  *		scratch_addr		Page in p, scratch space
7289  *		path			NULL terminated path
7290  *
7291  * Returns:	KERN_SUCCESS		Success
7292  *		!KERN_SUCCESS           See execve/mac_execve for error codes
7293  *
7294  * Notes:	The process that is passed in is the first manufactured
7295  *		process on the system, and gets here via bsd_ast() firing
7296  *		for the first time.  This is done to ensure that bsd_init()
7297  *		has run to completion.
7298  *
7299  *		The address map of the first manufactured process matches the
7300  *		word width of the kernel. Once the self-exec completes, the
7301  *		initproc might be different.
7302  */
7303 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)7304 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
7305 {
7306 	int retval[2];
7307 	int error;
7308 	struct execve_args init_exec_args;
7309 	user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
7310 
7311 	/*
7312 	 * Validate inputs and pre-conditions
7313 	 */
7314 	assert(p);
7315 	assert(scratch_addr);
7316 	assert(path);
7317 
7318 	/*
7319 	 * Copy out program name.
7320 	 */
7321 	size_t path_length = strlen(path) + 1;
7322 	argv0 = scratch_addr;
7323 	error = copyout(path, argv0, path_length);
7324 	if (error) {
7325 		return error;
7326 	}
7327 
7328 	scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
7329 
7330 	/*
7331 	 * Put out first (and only) argument, similarly.
7332 	 * Assumes everything fits in a page as allocated above.
7333 	 */
7334 	if (boothowto & RB_SINGLE) {
7335 		const char *init_args = "-s";
7336 		size_t init_args_length = strlen(init_args) + 1;
7337 
7338 		argv1 = scratch_addr;
7339 		error = copyout(init_args, argv1, init_args_length);
7340 		if (error) {
7341 			return error;
7342 		}
7343 
7344 		scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
7345 	}
7346 
7347 	if (proc_is64bit(p)) {
7348 		user64_addr_t argv64bit[3] = {};
7349 
7350 		argv64bit[0] = argv0;
7351 		argv64bit[1] = argv1;
7352 		argv64bit[2] = USER_ADDR_NULL;
7353 
7354 		error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
7355 		if (error) {
7356 			return error;
7357 		}
7358 	} else {
7359 		user32_addr_t argv32bit[3] = {};
7360 
7361 		argv32bit[0] = (user32_addr_t)argv0;
7362 		argv32bit[1] = (user32_addr_t)argv1;
7363 		argv32bit[2] = USER_ADDR_NULL;
7364 
7365 		error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
7366 		if (error) {
7367 			return error;
7368 		}
7369 	}
7370 
7371 	/*
7372 	 * Set up argument block for fake call to execve.
7373 	 */
7374 	init_exec_args.fname = argv0;
7375 	init_exec_args.argp = scratch_addr;
7376 	init_exec_args.envp = USER_ADDR_NULL;
7377 
7378 	/*
7379 	 * So that init task is set with uid,gid 0 token
7380 	 *
7381 	 * The access to the cred is safe:
7382 	 * the proc isn't running yet, it's stable.
7383 	 */
7384 	set_security_token(p, proc_ucred_unsafe(p));
7385 
7386 	return execve(p, &init_exec_args, retval);
7387 }
7388 
7389 static const char * init_programs[] = {
7390 #if DEBUG
7391 	"/usr/appleinternal/sbin/launchd.debug",
7392 #endif
7393 #if DEVELOPMENT || DEBUG
7394 	"/usr/appleinternal/sbin/launchd.development",
7395 #endif
7396 	"/sbin/launchd",
7397 };
7398 
7399 /*
7400  * load_init_program
7401  *
7402  * Description:	Load the "init" program; in most cases, this will be "launchd"
7403  *
7404  * Parameters:	p			Process to call execve() to create
7405  *					the "init" program
7406  *
7407  * Returns:	(void)
7408  *
7409  * Notes:	The process that is passed in is the first manufactured
7410  *		process on the system, and gets here via bsd_ast() firing
7411  *		for the first time.  This is done to ensure that bsd_init()
7412  *		has run to completion.
7413  *
7414  *		In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
7415  *		may be used to select a specific launchd executable. As with
7416  *		the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
7417  *		will force /sbin/launchd to be selected.
7418  *
7419  *              Search order by build:
7420  *
7421  * DEBUG	DEVELOPMENT	RELEASE		PATH
7422  * ----------------------------------------------------------------------------------
7423  * 1		1		NA		/usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
7424  * 2		NA		NA		/usr/appleinternal/sbin/launchd.debug
7425  * 3		2		NA		/usr/appleinternal/sbin/launchd.development
7426  * 4		3		1		/sbin/launchd
7427  */
7428 void
load_init_program(proc_t p)7429 load_init_program(proc_t p)
7430 {
7431 	uint32_t i;
7432 	int error;
7433 	vm_map_t map = current_map();
7434 	mach_vm_offset_t scratch_addr = 0;
7435 	mach_vm_size_t map_page_size = vm_map_page_size(map);
7436 
7437 
7438 	(void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size,
7439 	    VM_MAP_KERNEL_FLAGS_ANYWHERE());
7440 #if CONFIG_MEMORYSTATUS
7441 	(void) memorystatus_init_at_boot_snapshot();
7442 #endif /* CONFIG_MEMORYSTATUS */
7443 
7444 #if DEBUG || DEVELOPMENT
7445 	/* Check for boot-arg suffix first */
7446 	char launchd_suffix[64];
7447 	if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
7448 		char launchd_path[128];
7449 		boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
7450 		    (strcmp(launchd_suffix, "release") == 0));
7451 
7452 		if (is_release_suffix) {
7453 			printf("load_init_program: attempting to load /sbin/launchd\n");
7454 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
7455 			if (!error) {
7456 				return;
7457 			}
7458 
7459 			panic("Process 1 exec of launchd.release failed, errno %d", error);
7460 		} else {
7461 			strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
7462 			strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
7463 
7464 			printf("load_init_program: attempting to load %s\n", launchd_path);
7465 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
7466 			if (!error) {
7467 				return;
7468 			} else if (error != ENOENT) {
7469 				printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
7470 			}
7471 		}
7472 	}
7473 #endif
7474 
7475 	error = ENOENT;
7476 	for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
7477 		printf("load_init_program: attempting to load %s\n", init_programs[i]);
7478 		error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
7479 		if (!error) {
7480 			return;
7481 		} else if (error != ENOENT) {
7482 			printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
7483 		}
7484 	}
7485 
7486 	panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
7487 }
7488 
7489 /*
7490  * load_return_to_errno
7491  *
7492  * Description:	Convert a load_return_t (Mach error) to an errno (BSD error)
7493  *
7494  * Parameters:	lrtn			Mach error number
7495  *
7496  * Returns:	(int)			BSD error number
7497  *		0			Success
7498  *		EBADARCH		Bad architecture
7499  *		EBADMACHO		Bad Mach object file
7500  *		ESHLIBVERS		Bad shared library version
7501  *		ENOMEM			Out of memory/resource shortage
7502  *		EACCES			Access denied
7503  *		ENOENT			Entry not found (usually "file does
7504  *					does not exist")
7505  *		EIO			An I/O error occurred
7506  *		EBADEXEC		The executable is corrupt/unknown
7507  */
7508 static int
load_return_to_errno(load_return_t lrtn)7509 load_return_to_errno(load_return_t lrtn)
7510 {
7511 	switch (lrtn) {
7512 	case LOAD_SUCCESS:
7513 		return 0;
7514 	case LOAD_BADARCH:
7515 		return EBADARCH;
7516 	case LOAD_BADMACHO:
7517 	case LOAD_BADMACHO_UPX:
7518 		return EBADMACHO;
7519 	case LOAD_SHLIB:
7520 		return ESHLIBVERS;
7521 	case LOAD_NOSPACE:
7522 	case LOAD_RESOURCE:
7523 		return ENOMEM;
7524 	case LOAD_PROTECT:
7525 		return EACCES;
7526 	case LOAD_ENOENT:
7527 		return ENOENT;
7528 	case LOAD_IOERROR:
7529 		return EIO;
7530 	case LOAD_DECRYPTFAIL:
7531 		return EAUTH;
7532 	case LOAD_FAILURE:
7533 	default:
7534 		return EBADEXEC;
7535 	}
7536 }
7537 
7538 #include <mach/mach_types.h>
7539 #include <mach/vm_prot.h>
7540 #include <mach/semaphore.h>
7541 #include <mach/sync_policy.h>
7542 #include <kern/clock.h>
7543 #include <mach/kern_return.h>
7544 
7545 /*
7546  * execargs_alloc
7547  *
7548  * Description:	Allocate the block of memory used by the execve arguments.
7549  *		At the same time, we allocate a page so that we can read in
7550  *		the first page of the image.
7551  *
7552  * Parameters:	struct image_params *	the image parameter block
7553  *
7554  * Returns:	0			Success
7555  *		EINVAL			Invalid argument
7556  *		EACCES			Permission denied
7557  *		EINTR			Interrupted function
7558  *		ENOMEM			Not enough space
7559  *
7560  * Notes:	This is a temporary allocation into the kernel address space
7561  *		to enable us to copy arguments in from user space.  This is
7562  *		necessitated by not mapping the process calling execve() into
7563  *		the kernel address space during the execve() system call.
7564  *
7565  *		We assemble the argument and environment, etc., into this
7566  *		region before copying it as a single block into the child
7567  *		process address space (at the top or bottom of the stack,
7568  *		depending on which way the stack grows; see the function
7569  *		exec_copyout_strings() for details).
7570  *
7571  *		This ends up with a second (possibly unnecessary) copy compared
7572  *		with assembing the data directly into the child address space,
7573  *		instead, but since we cannot be guaranteed that the parent has
7574  *		not modified its environment, we can't really know that it's
7575  *		really a block there as well.
7576  */
7577 
7578 
7579 static int execargs_waiters = 0;
7580 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
7581 
7582 static void
execargs_lock_lock(void)7583 execargs_lock_lock(void)
7584 {
7585 	lck_mtx_lock_spin(&execargs_cache_lock);
7586 }
7587 
7588 static void
execargs_lock_unlock(void)7589 execargs_lock_unlock(void)
7590 {
7591 	lck_mtx_unlock(&execargs_cache_lock);
7592 }
7593 
7594 static wait_result_t
execargs_lock_sleep(void)7595 execargs_lock_sleep(void)
7596 {
7597 	return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
7598 }
7599 
7600 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)7601 execargs_purgeable_allocate(char **execarg_address)
7602 {
7603 	mach_vm_offset_t addr = 0;
7604 	kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
7605 	    BSD_PAGEABLE_SIZE_PER_EXEC,
7606 	    VM_MAP_KERNEL_FLAGS_ANYWHERE(.vmf_purgeable = true));
7607 	*execarg_address = (char *)addr;
7608 	assert(kr == KERN_SUCCESS);
7609 	return kr;
7610 }
7611 
7612 static kern_return_t
execargs_purgeable_reference(void * execarg_address)7613 execargs_purgeable_reference(void *execarg_address)
7614 {
7615 	int state = VM_PURGABLE_NONVOLATILE;
7616 	kern_return_t kr = vm_map_purgable_control(bsd_pageable_map,
7617 	    (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7618 
7619 	assert(kr == KERN_SUCCESS);
7620 	return kr;
7621 }
7622 
7623 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)7624 execargs_purgeable_volatilize(void *execarg_address)
7625 {
7626 	int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
7627 	kern_return_t kr;
7628 	kr = vm_map_purgable_control(bsd_pageable_map,
7629 	    (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7630 
7631 	assert(kr == KERN_SUCCESS);
7632 
7633 	return kr;
7634 }
7635 
7636 static void
execargs_wakeup_waiters(void)7637 execargs_wakeup_waiters(void)
7638 {
7639 	thread_wakeup(&execargs_free_count);
7640 }
7641 
7642 static int
execargs_alloc(struct image_params * imgp)7643 execargs_alloc(struct image_params *imgp)
7644 {
7645 	kern_return_t kret;
7646 	wait_result_t res;
7647 	int i, cache_index = -1;
7648 
7649 	execargs_lock_lock();
7650 
7651 	while (execargs_free_count == 0) {
7652 		execargs_waiters++;
7653 		res = execargs_lock_sleep();
7654 		execargs_waiters--;
7655 		if (res != THREAD_AWAKENED) {
7656 			execargs_lock_unlock();
7657 			return EINTR;
7658 		}
7659 	}
7660 
7661 	execargs_free_count--;
7662 
7663 	for (i = 0; i < execargs_cache_size; i++) {
7664 		vm_offset_t element = execargs_cache[i];
7665 		if (element) {
7666 			cache_index = i;
7667 			imgp->ip_strings = (char *)(execargs_cache[i]);
7668 			execargs_cache[i] = 0;
7669 			break;
7670 		}
7671 	}
7672 
7673 	assert(execargs_free_count >= 0);
7674 
7675 	execargs_lock_unlock();
7676 
7677 	if (cache_index == -1) {
7678 		kret = execargs_purgeable_allocate(&imgp->ip_strings);
7679 	} else {
7680 		kret = execargs_purgeable_reference(imgp->ip_strings);
7681 	}
7682 
7683 	assert(kret == KERN_SUCCESS);
7684 	if (kret != KERN_SUCCESS) {
7685 		return ENOMEM;
7686 	}
7687 
7688 	/* last page used to read in file headers */
7689 	imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
7690 	imgp->ip_strendp = imgp->ip_strings;
7691 	imgp->ip_argspace = NCARGS;
7692 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
7693 
7694 	return 0;
7695 }
7696 
7697 /*
7698  * execargs_free
7699  *
7700  * Description:	Free the block of memory used by the execve arguments and the
7701  *		first page of the executable by a previous call to the function
7702  *		execargs_alloc().
7703  *
7704  * Parameters:	struct image_params *	the image parameter block
7705  *
7706  * Returns:	0			Success
7707  *		EINVAL			Invalid argument
7708  *		EINTR			Oeration interrupted
7709  */
7710 static int
execargs_free(struct image_params * imgp)7711 execargs_free(struct image_params *imgp)
7712 {
7713 	kern_return_t kret;
7714 	int i;
7715 	boolean_t needs_wakeup = FALSE;
7716 
7717 	kret = execargs_purgeable_volatilize(imgp->ip_strings);
7718 
7719 	execargs_lock_lock();
7720 	execargs_free_count++;
7721 
7722 	for (i = 0; i < execargs_cache_size; i++) {
7723 		vm_offset_t element = execargs_cache[i];
7724 		if (element == 0) {
7725 			execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
7726 			imgp->ip_strings = NULL;
7727 			break;
7728 		}
7729 	}
7730 
7731 	assert(imgp->ip_strings == NULL);
7732 
7733 	if (execargs_waiters > 0) {
7734 		needs_wakeup = TRUE;
7735 	}
7736 
7737 	execargs_lock_unlock();
7738 
7739 	if (needs_wakeup == TRUE) {
7740 		execargs_wakeup_waiters();
7741 	}
7742 
7743 	return kret == KERN_SUCCESS ? 0 : EINVAL;
7744 }
7745 
7746 void
uthread_set_exec_data(struct uthread * uth,struct image_params * imgp)7747 uthread_set_exec_data(struct uthread *uth, struct image_params *imgp)
7748 {
7749 	uth->uu_save.uus_exec_data.imgp = imgp;
7750 }
7751 
7752 size_t
thread_get_current_exec_path(char * path,size_t size)7753 thread_get_current_exec_path(char *path, size_t size)
7754 {
7755 	struct uthread *uth = current_uthread();
7756 	struct image_params *imgp = uth->uu_save.uus_exec_data.imgp;
7757 	size_t string_size = 0;
7758 	char *exec_path;
7759 
7760 	if (path == NULL || imgp == NULL || imgp->ip_strings == NULL) {
7761 		return 0;
7762 	}
7763 
7764 	exec_path = imgp->ip_strings + strlen(EXECUTABLE_KEY);
7765 	string_size = imgp->ip_strendp - exec_path;
7766 	string_size = MIN(MAXPATHLEN, string_size);
7767 	string_size = MIN(size, string_size);
7768 
7769 	string_size = strlcpy(path, exec_path, string_size);
7770 	return string_size;
7771 }
7772 static void
exec_resettextvp(proc_t p,struct image_params * imgp)7773 exec_resettextvp(proc_t p, struct image_params *imgp)
7774 {
7775 	vnode_t vp;
7776 	off_t offset;
7777 	vnode_t tvp  = p->p_textvp;
7778 	int ret;
7779 
7780 	vp = imgp->ip_vp;
7781 	offset = imgp->ip_arch_offset;
7782 
7783 	if (vp == NULLVP) {
7784 		panic("exec_resettextvp: expected valid vp");
7785 	}
7786 
7787 	ret = vnode_ref(vp);
7788 	proc_lock(p);
7789 	if (ret == 0) {
7790 		p->p_textvp = vp;
7791 		p->p_textoff = offset;
7792 	} else {
7793 		p->p_textvp = NULLVP;   /* this is paranoia */
7794 		p->p_textoff = 0;
7795 	}
7796 	proc_unlock(p);
7797 
7798 	if (tvp != NULLVP) {
7799 		if (vnode_getwithref(tvp) == 0) {
7800 			vnode_rele(tvp);
7801 			vnode_put(tvp);
7802 		}
7803 	}
7804 }
7805 
7806 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
7807 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
7808 
7809 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)7810 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
7811 {
7812 	static char const nibble[] = "0123456789abcdef";
7813 
7814 	/* Apparently still the safest way to get a hex representation
7815 	 * of binary data.
7816 	 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
7817 	 * <rdar://problem/33328859> confusion around %*D/%nD in printf
7818 	 */
7819 	for (int i = 0; i < CS_CDHASH_LEN; ++i) {
7820 		str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
7821 		str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
7822 	}
7823 	str[CS_CDHASH_STRING_SIZE - 1] = 0;
7824 }
7825 
7826 /*
7827  * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
7828  *
7829  * Description: Waits for the userspace daemon to respond to the request
7830  *              we made. Function declared non inline to be visible in
7831  *		stackshots and spindumps as well as debugging.
7832  */
7833 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)7834 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
7835 {
7836 	return find_code_signature(task_access_port, new_pid);
7837 }
7838 
7839 /*
7840  * Update signature dependent process state, called by
7841  * process_signature.
7842  */
7843 static int
proc_process_signature(proc_t p,os_reason_t * signature_failure_reason)7844 proc_process_signature(proc_t p, os_reason_t *signature_failure_reason)
7845 {
7846 	int error = 0;
7847 	char const *error_msg = NULL;
7848 
7849 	kern_return_t kr = machine_task_process_signature(proc_get_task_raw(p), proc_platform(p), proc_sdk(p), &error_msg);
7850 
7851 	if (kr != KERN_SUCCESS) {
7852 		error = EINVAL;
7853 
7854 		if (error_msg != NULL) {
7855 			uint32_t error_msg_len = (uint32_t)strlen(error_msg) + 1;
7856 			mach_vm_address_t data_addr = 0;
7857 			int reason_error = 0;
7858 			int kcdata_error = 0;
7859 
7860 			os_reason_t reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7861 			reason->osr_flags = OS_REASON_FLAG_GENERATE_CRASH_REPORT | OS_REASON_FLAG_CONSISTENT_FAILURE;
7862 
7863 			if ((reason_error = os_reason_alloc_buffer_noblock(reason,
7864 			    kcdata_estimate_required_buffer_size(1, error_msg_len))) == 0 &&
7865 			    (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
7866 			    EXIT_REASON_USER_DESC, error_msg_len,
7867 			    &data_addr)) == KERN_SUCCESS) {
7868 				kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
7869 				    error_msg, error_msg_len);
7870 
7871 				if (mc_error != KERN_SUCCESS) {
7872 					printf("process_signature: failed to copy reason string (kcdata_memcpy error: %d)\n",
7873 					    mc_error);
7874 				}
7875 			} else {
7876 				printf("failed to allocate space for reason string (os_reason_alloc_buffer error: %d, kcdata error: %d, length: %u)\n",
7877 				    reason_error, kcdata_error, error_msg_len);
7878 			}
7879 
7880 			assert(*signature_failure_reason == NULL); // shouldn't have gotten so far
7881 			*signature_failure_reason = reason;
7882 		}
7883 	}
7884 	return error;
7885 }
7886 
7887 static int
process_signature(proc_t p,struct image_params * imgp)7888 process_signature(proc_t p, struct image_params *imgp)
7889 {
7890 	mach_port_t port = IPC_PORT_NULL;
7891 	kern_return_t kr = KERN_FAILURE;
7892 	int error = EACCES;
7893 	boolean_t unexpected_failure = FALSE;
7894 	struct cs_blob *csb;
7895 	boolean_t require_success = FALSE;
7896 	int spawn = (imgp->ip_flags & IMGPF_SPAWN);
7897 	const int vfexec = 0;
7898 	os_reason_t signature_failure_reason = OS_REASON_NULL;
7899 
7900 	/*
7901 	 * Override inherited code signing flags with the
7902 	 * ones for the process that is being successfully
7903 	 * loaded
7904 	 */
7905 	proc_lock(p);
7906 	proc_csflags_update(p, imgp->ip_csflags);
7907 	proc_unlock(p);
7908 
7909 	/* Set the switch_protect flag on the map */
7910 	if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
7911 		vm_map_switch_protect(get_task_map(proc_task(p)), TRUE);
7912 	}
7913 	/* set the cs_enforced flags in the map */
7914 	if (proc_getcsflags(p) & CS_ENFORCEMENT) {
7915 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), TRUE);
7916 	} else {
7917 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), FALSE);
7918 	}
7919 
7920 	/*
7921 	 * image activation may be failed due to policy
7922 	 * which is unexpected but security framework does not
7923 	 * approve of exec, kill and return immediately.
7924 	 */
7925 	if (imgp->ip_mac_return != 0) {
7926 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7927 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
7928 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7929 		error = imgp->ip_mac_return;
7930 		unexpected_failure = TRUE;
7931 		goto done;
7932 	}
7933 
7934 	if (imgp->ip_cs_error != OS_REASON_NULL) {
7935 		signature_failure_reason = imgp->ip_cs_error;
7936 		imgp->ip_cs_error = OS_REASON_NULL;
7937 		error = EACCES;
7938 		goto done;
7939 	}
7940 
7941 	/* call the launch constraints hook */
7942 	os_reason_t launch_constraint_reason;
7943 	if ((error = mac_proc_check_launch_constraints(p, imgp, &launch_constraint_reason)) != 0) {
7944 		signature_failure_reason = launch_constraint_reason;
7945 		goto done;
7946 	}
7947 
7948 #if XNU_TARGET_OS_OSX
7949 	/* Check for platform passed in spawn attr if iOS binary is being spawned */
7950 	if (proc_platform(p) == PLATFORM_IOS) {
7951 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
7952 		if (psa == NULL || psa->psa_platform == 0) {
7953 			boolean_t no_sandbox_entitled = FALSE;
7954 #if DEBUG || DEVELOPMENT
7955 			/*
7956 			 * Allow iOS binaries to spawn on internal systems
7957 			 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
7958 			 * boot-arg set to true
7959 			 */
7960 			if (unentitled_ios_sim_launch) {
7961 				no_sandbox_entitled = TRUE;
7962 			} else {
7963 				no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
7964 				    (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
7965 			}
7966 #endif /* DEBUG || DEVELOPMENT */
7967 			if (!no_sandbox_entitled) {
7968 				signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7969 				    EXEC_EXIT_REASON_WRONG_PLATFORM);
7970 				error = EACCES;
7971 				goto done;
7972 			}
7973 			printf("Allowing spawn of iOS binary %s since it has "
7974 			    "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
7975 			    "boot-arg set to true\n", p->p_name);
7976 		} else if (psa->psa_platform != PLATFORM_IOS) {
7977 			/* Simulator binary spawned with wrong platform */
7978 			signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7979 			    EXEC_EXIT_REASON_WRONG_PLATFORM);
7980 			error = EACCES;
7981 			goto done;
7982 		} else {
7983 			printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
7984 			    p->p_name);
7985 		}
7986 	}
7987 #endif /* XNU_TARGET_OS_OSX */
7988 
7989 	/* If the code signature came through the image activation path, we skip the
7990 	 * taskgated / externally attached path. */
7991 	if (imgp->ip_csflags & CS_SIGNED) {
7992 		error = 0;
7993 		goto done;
7994 	}
7995 
7996 	/* The rest of the code is for signatures that either already have been externally
7997 	 * attached (likely, but not necessarily by a previous run through the taskgated
7998 	 * path), or that will now be attached by taskgated. */
7999 
8000 	kr = task_get_task_access_port(proc_task(p), &port);
8001 	if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
8002 		error = 0;
8003 		if (require_success) {
8004 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
8005 			    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
8006 			signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
8007 			error = EACCES;
8008 		}
8009 		goto done;
8010 	}
8011 
8012 	/*
8013 	 * taskgated returns KERN_SUCCESS if it has completed its work
8014 	 * and the exec should continue, KERN_FAILURE if the exec should
8015 	 * fail, or it may error out with different error code in an
8016 	 * event of mig failure (e.g. process was signalled during the
8017 	 * rpc call, taskgated died, mig server died etc.).
8018 	 */
8019 
8020 	kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
8021 	switch (kr) {
8022 	case KERN_SUCCESS:
8023 		error = 0;
8024 		break;
8025 	case KERN_FAILURE:
8026 		error = EACCES;
8027 
8028 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
8029 		    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
8030 		signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
8031 		goto done;
8032 	default:
8033 		error = EACCES;
8034 
8035 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
8036 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
8037 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
8038 		unexpected_failure = TRUE;
8039 		goto done;
8040 	}
8041 
8042 	/* Only do this if exec_resettextvp() did not fail */
8043 	if (p->p_textvp != NULLVP) {
8044 		csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
8045 
8046 		if (csb != NULL) {
8047 			/* As the enforcement we can do here is very limited, we only allow things that
8048 			 * are the only reason why this code path still exists:
8049 			 * Adhoc signed non-platform binaries without special cs_flags and without any
8050 			 * entitlements (unrestricted ones still pass AMFI). */
8051 			if (
8052 				/* Revalidate the blob if necessary through bumped generation count. */
8053 				(ubc_cs_generation_check(p->p_textvp) == 0 ||
8054 				ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
8055 				/* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
8056 				(csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
8057 				/* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
8058 				csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
8059 				CSSLOT_SIGNATURESLOT,
8060 				CSMAGIC_BLOBWRAPPER) == NULL &&
8061 				/* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
8062 				csb->csb_platform_binary == 0 &&
8063 				/* No entitlements, not even unrestricted ones. */
8064 				csb->csb_entitlements_blob == NULL &&
8065 				csb->csb_der_entitlements_blob == NULL) {
8066 				proc_lock(p);
8067 				proc_csflags_set(p, CS_SIGNED | CS_VALID);
8068 				proc_unlock(p);
8069 			} else {
8070 				uint8_t cdhash[CS_CDHASH_LEN];
8071 				char cdhash_string[CS_CDHASH_STRING_SIZE];
8072 				proc_getcdhash(p, cdhash);
8073 				cdhash_to_string(cdhash_string, cdhash);
8074 				printf("ignoring detached code signature on '%s' with cdhash '%s' "
8075 				    "because it is invalid, or not a simple adhoc signature.\n",
8076 				    p->p_name, cdhash_string);
8077 			}
8078 		}
8079 	}
8080 
8081 done:
8082 	if (0 == error) {
8083 		/*
8084 		 * Update the new process's signature-dependent process state.
8085 		 * state.
8086 		 */
8087 
8088 		error = proc_process_signature(p, &signature_failure_reason);
8089 	}
8090 
8091 	if (0 == error) {
8092 		/*
8093 		 * Update the new main thread's signature-dependent thread
8094 		 * state. This was also called when the thread was created,
8095 		 * but for the main thread the signature was not yet attached
8096 		 * at that time.
8097 		 */
8098 		kr = thread_process_signature(imgp->ip_new_thread, proc_get_task_raw(p));
8099 
8100 		if (kr != KERN_SUCCESS) {
8101 			error = EINVAL;
8102 			signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MACHINE_THREAD);
8103 		}
8104 	}
8105 
8106 	if (0 == error) {
8107 		/* The process's code signature related properties are
8108 		 * fully set up, so this is an opportune moment to log
8109 		 * platform binary execution, if desired. */
8110 		if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
8111 			uint8_t cdhash[CS_CDHASH_LEN];
8112 			char cdhash_string[CS_CDHASH_STRING_SIZE];
8113 			proc_getcdhash(p, cdhash);
8114 			cdhash_to_string(cdhash_string, cdhash);
8115 
8116 			os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
8117 			    "'%s' with cdhash %s\n", p->p_name, cdhash_string);
8118 		}
8119 	} else {
8120 		if (!unexpected_failure) {
8121 			proc_csflags_set(p, CS_KILLED);
8122 		}
8123 		/* make very sure execution fails */
8124 		if (vfexec || spawn) {
8125 			assert(signature_failure_reason != OS_REASON_NULL);
8126 			psignal_vfork_with_reason(p, proc_task(p), imgp->ip_new_thread,
8127 			    SIGKILL, signature_failure_reason);
8128 			signature_failure_reason = OS_REASON_NULL;
8129 			error = 0;
8130 		} else {
8131 			assert(signature_failure_reason != OS_REASON_NULL);
8132 			psignal_with_reason(p, SIGKILL, signature_failure_reason);
8133 			signature_failure_reason = OS_REASON_NULL;
8134 		}
8135 	}
8136 
8137 	if (port != IPC_PORT_NULL) {
8138 		ipc_port_release_send(port);
8139 	}
8140 
8141 	/* If we hit this, we likely would have leaked an exit reason */
8142 	assert(signature_failure_reason == OS_REASON_NULL);
8143 	return error;
8144 }
8145 
8146 /*
8147  * Typically as soon as we start executing this process, the
8148  * first instruction will trigger a VM fault to bring the text
8149  * pages (as executable) into the address space, followed soon
8150  * thereafter by dyld data structures (for dynamic executable).
8151  * To optimize this, as well as improve support for hardware
8152  * debuggers that can only access resident pages present
8153  * in the process' page tables, we prefault some pages if
8154  * possible. Errors are non-fatal.
8155  */
8156 #ifndef PREVENT_CALLER_STACK_USE
8157 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
8158 #endif
8159 
8160 /*
8161  * Prefaulting dyld data does not work (rdar://76621401)
8162  */
8163 #define FIXED_76621401 0
8164 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(__unused proc_t p,__unused struct image_params * imgp,__unused load_result_t * load_result)8165 exec_prefault_data(
8166 	__unused proc_t p,
8167 	__unused struct image_params *imgp,
8168 	__unused load_result_t *load_result)
8169 {
8170 #if FIXED_76621401
8171 	int ret;
8172 	size_t expected_all_image_infos_size;
8173 #endif /* FIXED_76621401 */
8174 	kern_return_t kr;
8175 
8176 	/*
8177 	 * Prefault executable or dyld entry point.
8178 	 */
8179 	if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8180 		DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
8181 	}
8182 	kr = vm_fault(current_map(),
8183 	    vm_map_trunc_page(load_result->entry_point,
8184 	    vm_map_page_mask(current_map())),
8185 	    VM_PROT_READ | VM_PROT_EXECUTE,
8186 	    FALSE, VM_KERN_MEMORY_NONE,
8187 	    THREAD_UNINT, NULL, 0);
8188 	if (kr != KERN_SUCCESS) {
8189 		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);
8190 	}
8191 
8192 #if FIXED_76621401
8193 	if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
8194 		expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
8195 	} else {
8196 		expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
8197 	}
8198 
8199 	/* Decode dyld anchor structure from <mach-o/dyld_images.h> */
8200 	if (load_result->dynlinker &&
8201 	    load_result->all_image_info_addr &&
8202 	    load_result->all_image_info_size >= expected_all_image_infos_size) {
8203 		union {
8204 			struct user64_dyld_all_image_infos      infos64;
8205 			struct user32_dyld_all_image_infos      infos32;
8206 		} all_image_infos;
8207 
8208 		/*
8209 		 * Pre-fault to avoid copyin() going through the trap handler
8210 		 * and recovery path.
8211 		 */
8212 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8213 			DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
8214 		}
8215 		kr = vm_fault(current_map(),
8216 		    vm_map_trunc_page(load_result->all_image_info_addr,
8217 		    vm_map_page_mask(current_map())),
8218 		    VM_PROT_READ | VM_PROT_WRITE,
8219 		    FALSE, VM_KERN_MEMORY_NONE,
8220 		    THREAD_UNINT, NULL, 0);
8221 		if (kr != KERN_SUCCESS) {
8222 //			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);
8223 		}
8224 		if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
8225 			/* all_image_infos straddles a page */
8226 			kr = vm_fault(current_map(),
8227 			    vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
8228 			    vm_map_page_mask(current_map())),
8229 			    VM_PROT_READ | VM_PROT_WRITE,
8230 			    FALSE, VM_KERN_MEMORY_NONE,
8231 			    THREAD_UNINT, NULL, 0);
8232 			if (kr != KERN_SUCCESS) {
8233 //				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);
8234 			}
8235 		}
8236 
8237 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8238 			DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
8239 		}
8240 		ret = copyin((user_addr_t)load_result->all_image_info_addr,
8241 		    &all_image_infos,
8242 		    expected_all_image_infos_size);
8243 		if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
8244 			user_addr_t notification_address;
8245 			user_addr_t dyld_image_address;
8246 			user_addr_t dyld_version_address;
8247 			user_addr_t dyld_all_image_infos_address;
8248 			user_addr_t dyld_slide_amount;
8249 
8250 			if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
8251 				notification_address = (user_addr_t)all_image_infos.infos64.notification;
8252 				dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
8253 				dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
8254 				dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
8255 			} else {
8256 				notification_address = all_image_infos.infos32.notification;
8257 				dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
8258 				dyld_version_address = all_image_infos.infos32.dyldVersion;
8259 				dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
8260 			}
8261 
8262 			/*
8263 			 * dyld statically sets up the all_image_infos in its Mach-O
8264 			 * binary at static link time, with pointers relative to its default
8265 			 * load address. Since ASLR might slide dyld before its first
8266 			 * instruction is executed, "dyld_slide_amount" tells us how far
8267 			 * dyld was loaded compared to its default expected load address.
8268 			 * All other pointers into dyld's image should be adjusted by this
8269 			 * amount. At some point later, dyld will fix up pointers to take
8270 			 * into account the slide, at which point the all_image_infos_address
8271 			 * field in the structure will match the runtime load address, and
8272 			 * "dyld_slide_amount" will be 0, if we were to consult it again.
8273 			 */
8274 
8275 			dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
8276 
8277 #if 0
8278 			kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
8279 			    (uint64_t)load_result->all_image_info_addr,
8280 			    all_image_infos.infos32.version,
8281 			    (uint64_t)notification_address,
8282 			    (uint64_t)dyld_image_address,
8283 			    (uint64_t)dyld_version_address,
8284 			    (uint64_t)dyld_all_image_infos_address);
8285 #endif
8286 
8287 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8288 				DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
8289 			}
8290 			kr = vm_fault(current_map(),
8291 			    vm_map_trunc_page(notification_address + dyld_slide_amount,
8292 			    vm_map_page_mask(current_map())),
8293 			    VM_PROT_READ | VM_PROT_EXECUTE,
8294 			    FALSE, VM_KERN_MEMORY_NONE,
8295 			    THREAD_UNINT, NULL, 0);
8296 			if (kr != KERN_SUCCESS) {
8297 //				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);
8298 			}
8299 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8300 				DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
8301 			}
8302 			kr = vm_fault(current_map(),
8303 			    vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
8304 			    vm_map_page_mask(current_map())),
8305 			    VM_PROT_READ | VM_PROT_EXECUTE,
8306 			    FALSE, VM_KERN_MEMORY_NONE,
8307 			    THREAD_UNINT, NULL, 0);
8308 			if (kr != KERN_SUCCESS) {
8309 //				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);
8310 			}
8311 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8312 				DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
8313 			}
8314 			kr = vm_fault(current_map(),
8315 			    vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
8316 			    vm_map_page_mask(current_map())),
8317 			    VM_PROT_READ,
8318 			    FALSE, VM_KERN_MEMORY_NONE,
8319 			    THREAD_UNINT, NULL, 0);
8320 			if (kr != KERN_SUCCESS) {
8321 //				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);
8322 			}
8323 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8324 				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);
8325 			}
8326 			kr = vm_fault(current_map(),
8327 			    vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
8328 			    vm_map_page_mask(current_map())),
8329 			    VM_PROT_READ | VM_PROT_WRITE,
8330 			    FALSE, VM_KERN_MEMORY_NONE,
8331 			    THREAD_UNINT, NULL, 0);
8332 			if (kr != KERN_SUCCESS) {
8333 //				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);
8334 			}
8335 		}
8336 	}
8337 #endif /* FIXED_76621401 */
8338 }
8339 
8340 static int
8341 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
8342 {
8343 #pragma unused(oidp, arg2, req)
8344 	int changed;
8345 	errno_t error;
8346 	uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
8347 
8348 	error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
8349 	if (error) {
8350 		return error;
8351 	}
8352 
8353 	if (changed) {
8354 		os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
8355 	}
8356 
8357 	return 0;
8358 }
8359 
8360 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
8361 
8362 SYSCTL_NODE(_kern, OID_AUTO, sec_transition,
8363     CTLFLAG_RD | CTLFLAG_LOCKED, 0, "sec_transition");
8364 
8365 
8366 SYSCTL_INT(_kern_sec_transition, OID_AUTO, available,
8367     CTLFLAG_RD | CTLFLAG_LOCKED, (int *)NULL, 0, "");
8368 
8369 
8370 #if DEBUG || DEVELOPMENT
8371 static int
sysctl_setup_ensure_pidversion_changes_on_exec(__unused int64_t in,int64_t * out)8372 sysctl_setup_ensure_pidversion_changes_on_exec(__unused int64_t in, int64_t *out)
8373 {
8374 	// Tweak nextpidversion to try to trigger a reuse (unless the exec code is doing the right thing)
8375 	int current_pid_version = proc_get_ro(current_proc())->p_idversion;
8376 	nextpidversion = current_pid_version;
8377 	*out = 0;
8378 	return KERN_SUCCESS;
8379 }
8380 
8381 SYSCTL_TEST_REGISTER(setup_ensure_pidversion_changes_on_exec, sysctl_setup_ensure_pidversion_changes_on_exec);
8382 #endif /* DEBUG || DEVELOPMENT */
8383