xref: /xnu-10063.121.3/bsd/kern/kern_exec.c (revision 2c2f96dc2b9a4408a43d3150ae9c105355ca3daa)
1 /*
2  * Copyright (c) 2000-2020 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Mach Operating System
31  * Copyright (c) 1987 Carnegie-Mellon University
32  * All rights reserved.  The CMU software License Agreement specifies
33  * the terms and conditions for use and redistribution.
34  */
35 
36 /*-
37  * Copyright (c) 1982, 1986, 1991, 1993
38  *	The Regents of the University of California.  All rights reserved.
39  * (c) UNIX System Laboratories, Inc.
40  * All or some portions of this file are derived from material licensed
41  * to the University of California by American Telephone and Telegraph
42  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
43  * the permission of UNIX System Laboratories, Inc.
44  *
45  * Redistribution and use in source and binary forms, with or without
46  * modification, are permitted provided that the following conditions
47  * are met:
48  * 1. Redistributions of source code must retain the above copyright
49  *    notice, this list of conditions and the following disclaimer.
50  * 2. Redistributions in binary form must reproduce the above copyright
51  *    notice, this list of conditions and the following disclaimer in the
52  *    documentation and/or other materials provided with the distribution.
53  * 3. All advertising materials mentioning features or use of this software
54  *    must display the following acknowledgement:
55  *	This product includes software developed by the University of
56  *	California, Berkeley and its contributors.
57  * 4. Neither the name of the University nor the names of its contributors
58  *    may be used to endorse or promote products derived from this software
59  *    without specific prior written permission.
60  *
61  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71  * SUCH DAMAGE.
72  *
73  *	from: @(#)kern_exec.c	8.1 (Berkeley) 6/10/93
74  */
75 /*
76  * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
77  * support for mandatory and extensible security protections.  This notice
78  * is included in support of clause 2.2 (b) of the Apple Public License,
79  * Version 2.0.
80  */
81 #include <machine/reg.h>
82 #include <machine/cpu_capabilities.h>
83 
84 #include <sys/cdefs.h>
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/filedesc.h>
88 #include <sys/kernel.h>
89 #include <sys/proc_internal.h>
90 #include <sys/kauth.h>
91 #include <sys/user.h>
92 #include <sys/socketvar.h>
93 #include <sys/malloc.h>
94 #include <sys/namei.h>
95 #include <sys/mount_internal.h>
96 #include <sys/vnode_internal.h>
97 #include <sys/file_internal.h>
98 #include <sys/stat.h>
99 #include <sys/uio_internal.h>
100 #include <sys/acct.h>
101 #include <sys/exec.h>
102 #include <sys/kdebug.h>
103 #include <sys/signal.h>
104 #include <sys/aio_kern.h>
105 #include <sys/sysproto.h>
106 #include <sys/sysctl.h>
107 #include <sys/persona.h>
108 #include <sys/reason.h>
109 #if SYSV_SHM
110 #include <sys/shm_internal.h>           /* shmexec() */
111 #endif
112 #include <sys/ubc_internal.h>           /* ubc_map() */
113 #include <sys/spawn.h>
114 #include <sys/spawn_internal.h>
115 #include <sys/process_policy.h>
116 #include <sys/codesign.h>
117 #include <sys/random.h>
118 #include <crypto/sha1.h>
119 
120 #include <libkern/libkern.h>
121 #include <libkern/crypto/sha2.h>
122 #include <security/audit/audit.h>
123 
124 #include <ipc/ipc_types.h>
125 
126 #include <mach/mach_param.h>
127 #include <mach/mach_types.h>
128 #include <mach/port.h>
129 #include <mach/task.h>
130 #include <mach/task_access.h>
131 #include <mach/thread_act.h>
132 #include <mach/vm_map.h>
133 #include <mach/mach_vm.h>
134 #include <mach/vm_param.h>
135 #include <mach_debug/mach_debug_types.h>
136 
137 #include <kern/sched_prim.h> /* thread_wakeup() */
138 #include <kern/affinity.h>
139 #include <kern/assert.h>
140 #include <kern/task.h>
141 #include <kern/thread.h>
142 #include <kern/coalition.h>
143 #include <kern/policy_internal.h>
144 #include <kern/kalloc.h>
145 #include <kern/zalloc.h> /* zone_userspace_reboot_checks() */
146 
147 #include <os/log.h>
148 
149 #if CONFIG_MACF
150 #include <security/mac_framework.h>
151 #include <security/mac_mach_internal.h>
152 #endif
153 
154 #if CONFIG_AUDIT
155 #include <bsm/audit_kevents.h>
156 #endif
157 
158 #if CONFIG_ARCADE
159 #include <kern/arcade.h>
160 #endif
161 
162 #include <vm/vm_map.h>
163 #include <vm/vm_kern.h>
164 #include <vm/vm_protos.h>
165 #include <vm/vm_kern.h>
166 #include <vm/vm_fault.h>
167 #include <vm/vm_pageout.h>
168 #include <vm/pmap.h>
169 #include <vm/vm_reclaim_internal.h>
170 
171 #include <kdp/kdp_dyld.h>
172 
173 #include <machine/machine_routines.h>
174 #include <machine/pal_routines.h>
175 
176 #include <pexpert/pexpert.h>
177 
178 #if CONFIG_MEMORYSTATUS
179 #include <sys/kern_memorystatus.h>
180 #endif
181 
182 #include <IOKit/IOBSD.h>
183 
184 #include "kern_exec_internal.h"
185 
186 #include <CodeSignature/Entitlements.h>
187 
188 #include <mach/exclaves.h>
189 
190 extern boolean_t vm_darkwake_mode;
191 
192 /* enable crash reports on various exec failures */
193 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
194 
195 #if XNU_TARGET_OS_OSX
196 #if __has_feature(ptrauth_calls)
197 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
198 #endif /* __has_feature(ptrauth_calls) */
199 
200 #if DEBUG || DEVELOPMENT
201 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
202 #endif /* DEBUG || DEVELOPMENT */
203 #endif /* XNU_TARGET_OS_OSX */
204 
205 #if CONFIG_DTRACE
206 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
207 extern void dtrace_proc_exec(proc_t);
208 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
209 
210 /*
211  * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
212  * we will store its value before actually calling it.
213  */
214 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
215 
216 #include <sys/dtrace_ptss.h>
217 #endif
218 
219 #if __has_feature(ptrauth_calls)
220 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
221     "vm_shared_region_per_team_id", 1);
222 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
223     "vm_shared_region_by_entitlement", 1);
224 
225 /* Upon userland request, reslide the shared cache. */
226 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
227     "vm_shared_region_reslide_aslr",
228 #if CONFIG_RESLIDE_SHARED_CACHE
229     1
230 #else
231     0
232 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
233     );
234 
235 /*
236  * Flag to control what processes should get shared cache randomize resliding
237  * after a fault in the shared cache region:
238  *
239  * 0 - all processes get a new randomized slide
240  * 1 - only platform processes get a new randomized slide
241  */
242 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
243     "vm_shared_region_reslide_restrict", 1);
244 
245 #if DEVELOPMENT || DEBUG
246 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
247     CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
248 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
249     CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
250 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
251     CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
252 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
253     CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
254 #endif
255 #endif /* __has_feature(ptrauth_calls) */
256 
257 #if DEVELOPMENT || DEBUG
258 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", true);
259 #else
260 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", false);
261 #endif
262 extern kern_return_t kern_register_userspace_coredump(task_t task, const char * name);
263 #define USERSPACE_COREDUMP_PANIC_ENTITLEMENT "com.apple.private.enable-coredump-on-panic"
264 #define USERSPACE_COREDUMP_PANIC_SEED_ENTITLEMENT \
265 	"com.apple.private.enable-coredump-on-panic-seed-privacy-approved"
266 
267 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
268 extern void task_set_did_exec_flag(task_t task);
269 extern void task_clear_exec_copy_flag(task_t task);
270 proc_t proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task,
271     task_t new_task, struct image_params *imgp, void **inherit);
272 boolean_t task_is_active(task_t);
273 boolean_t thread_is_active(thread_t thread);
274 void thread_copy_resource_info(thread_t dst_thread, thread_t src_thread);
275 void *ipc_importance_exec_switch_task(task_t old_task, task_t new_task);
276 extern void ipc_importance_release(void *elem);
277 extern boolean_t task_has_watchports(task_t task);
278 extern void task_set_no_smt(task_t task);
279 #if defined(HAS_APPLE_PAC)
280 char *task_get_vm_shared_region_id_and_jop_pid(task_t task, uint64_t *jop_pid);
281 #endif
282 task_t convert_port_to_task(ipc_port_t port);
283 
284 #if CONFIG_EXCLAVES
285 int task_add_conclave(task_t task, void *vnode, int64_t off, const char *task_conclave_id);
286 kern_return_t task_inherit_conclave(task_t old_task, task_t new_task, void *vnode, int64_t off);
287 #endif /* CONFIG_EXCLAVES */
288 
289 
290 /*
291  * Mach things for which prototypes are unavailable from Mach headers
292  */
293 #define IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND 0x1
294 void            ipc_task_enable(
295 	task_t          task);
296 void            ipc_task_reset(
297 	task_t          task);
298 void            ipc_thread_reset(
299 	thread_t        thread);
300 kern_return_t ipc_object_copyin(
301 	ipc_space_t             space,
302 	mach_port_name_t        name,
303 	mach_msg_type_name_t    msgt_name,
304 	ipc_object_t            *objectp,
305 	mach_port_context_t     context,
306 	mach_msg_guard_flags_t  *guard_flags,
307 	uint32_t                kmsg_flags);
308 void ipc_port_release_send(ipc_port_t);
309 
310 #if DEVELOPMENT || DEBUG
311 void task_importance_update_owner_info(task_t);
312 #endif
313 
314 extern struct savearea *get_user_regs(thread_t);
315 
316 __attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
317 
318 #include <kern/thread.h>
319 #include <kern/task.h>
320 #include <kern/ast.h>
321 #include <kern/mach_loader.h>
322 #include <kern/mach_fat.h>
323 #include <mach-o/fat.h>
324 #include <mach-o/loader.h>
325 #include <machine/vmparam.h>
326 #include <sys/imgact.h>
327 
328 #include <sys/sdt.h>
329 
330 
331 /*
332  * EAI_ITERLIMIT	The maximum number of times to iterate an image
333  *			activator in exec_activate_image() before treating
334  *			it as malformed/corrupt.
335  */
336 #define EAI_ITERLIMIT           3
337 
338 /*
339  * For #! interpreter parsing
340  */
341 #define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
342 #define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
343 
344 extern vm_map_t bsd_pageable_map;
345 extern const struct fileops vnops;
346 extern int nextpidversion;
347 
348 
349 #define USER_ADDR_ALIGN(addr, val) \
350 	( ( (user_addr_t)(addr) + (val) - 1) \
351 	        & ~((val) - 1) )
352 
353 /*
354  * For subsystem root support
355  */
356 #define SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT "com.apple.private.spawn-subsystem-root"
357 
358 /*
359  * Allow setting p_crash_behavior to trigger panic on crash
360  */
361 #define SPAWN_SET_PANIC_CRASH_BEHAVIOR "com.apple.private.spawn-panic-crash-behavior"
362 
363 /* Platform Code Exec Logging */
364 static int platform_exec_logging = 0;
365 
366 SYSCTL_DECL(_security_mac);
367 
368 SYSCTL_INT(_security_mac, OID_AUTO, platform_exec_logging, CTLFLAG_RW, &platform_exec_logging, 0,
369     "log cdhashes for all platform binary executions");
370 
371 static os_log_t peLog = OS_LOG_DEFAULT;
372 
373 struct exception_port_action_t {
374 	ipc_port_t port;
375 	_ps_port_action_t *port_action;
376 };
377 
378 struct exec_port_actions {
379 	uint32_t exception_port_count;
380 	uint32_t portwatch_count;
381 	uint32_t registered_count;
382 	struct exception_port_action_t *excport_array;
383 	ipc_port_t *portwatch_array;
384 	ipc_port_t *registered_array;
385 };
386 
387 struct image_params;    /* Forward */
388 static int exec_activate_image(struct image_params *imgp);
389 static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
390 static int load_return_to_errno(load_return_t lrtn);
391 static int execargs_alloc(struct image_params *imgp);
392 static int execargs_free(struct image_params *imgp);
393 static int exec_check_permissions(struct image_params *imgp);
394 static int exec_extract_strings(struct image_params *imgp);
395 static int exec_add_apple_strings(struct image_params *imgp, const load_result_t *load_result);
396 static int exec_handle_sugid(struct image_params *imgp);
397 static int sugid_scripts = 0;
398 SYSCTL_INT(_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
399 static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
400 static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
401 static void exec_resettextvp(proc_t, struct image_params *);
402 static int process_signature(proc_t, struct image_params *);
403 static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
404 static errno_t exec_handle_port_actions(struct image_params *imgp,
405     struct exec_port_actions *port_actions);
406 static errno_t exec_handle_exception_port_actions(const struct image_params *imgp,
407     const struct exec_port_actions *port_actions);
408 static errno_t exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
409     task_role_t psa_darwin_role, struct exec_port_actions *port_actions);
410 static void exec_port_actions_destroy(struct exec_port_actions *port_actions);
411 
412 /*
413  * exec_add_user_string
414  *
415  * Add the requested string to the string space area.
416  *
417  * Parameters;	struct image_params *		image parameter block
418  *		user_addr_t			string to add to strings area
419  *		int				segment from which string comes
420  *		boolean_t			TRUE if string contributes to NCARGS
421  *
422  * Returns:	0			Success
423  *		!0			Failure errno from copyinstr()
424  *
425  * Implicit returns:
426  *		(imgp->ip_strendp)	updated location of next add, if any
427  *		(imgp->ip_strspace)	updated byte count of space remaining
428  *		(imgp->ip_argspace) updated byte count of space in NCARGS
429  */
430 __attribute__((noinline))
431 static int
exec_add_user_string(struct image_params * imgp,user_addr_t str,int seg,boolean_t is_ncargs)432 exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
433 {
434 	int error = 0;
435 
436 	do {
437 		size_t len = 0;
438 		int space;
439 
440 		if (is_ncargs) {
441 			space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
442 		} else {
443 			space = imgp->ip_strspace;
444 		}
445 
446 		if (space <= 0) {
447 			error = E2BIG;
448 			break;
449 		}
450 
451 		if (!UIO_SEG_IS_USER_SPACE(seg)) {
452 			char *kstr = CAST_DOWN(char *, str);     /* SAFE */
453 			error = copystr(kstr, imgp->ip_strendp, space, &len);
454 		} else {
455 			error = copyinstr(str, imgp->ip_strendp, space, &len);
456 		}
457 
458 		imgp->ip_strendp += len;
459 		imgp->ip_strspace -= len;
460 		if (is_ncargs) {
461 			imgp->ip_argspace -= len;
462 		}
463 	} while (error == ENAMETOOLONG);
464 
465 	return error;
466 }
467 
468 /*
469  * dyld is now passed the executable path as a getenv-like variable
470  * in the same fashion as the stack_guard and malloc_entropy keys.
471  */
472 #define EXECUTABLE_KEY "executable_path="
473 
474 /*
475  * exec_save_path
476  *
477  * To support new app package launching for Mac OS X, the dyld needs the
478  * first argument to execve() stored on the user stack.
479  *
480  * Save the executable path name at the bottom of the strings area and set
481  * the argument vector pointer to the location following that to indicate
482  * the start of the argument and environment tuples, setting the remaining
483  * string space count to the size of the string area minus the path length.
484  *
485  * Parameters;	struct image_params *		image parameter block
486  *		char *				path used to invoke program
487  *		int				segment from which path comes
488  *
489  * Returns:	int			0	Success
490  *		EFAULT				Bad address
491  *	copy[in]str:EFAULT			Bad address
492  *	copy[in]str:ENAMETOOLONG		Filename too long
493  *
494  * Implicit returns:
495  *		(imgp->ip_strings)		saved path
496  *		(imgp->ip_strspace)		space remaining in ip_strings
497  *		(imgp->ip_strendp)		start of remaining copy area
498  *		(imgp->ip_argspace)		space remaining of NCARGS
499  *		(imgp->ip_applec)		Initial applev[0]
500  *
501  * Note:	We have to do this before the initial namei() since in the
502  *		path contains symbolic links, namei() will overwrite the
503  *		original path buffer contents.  If the last symbolic link
504  *		resolved was a relative pathname, we would lose the original
505  *		"path", which could be an absolute pathname. This might be
506  *		unacceptable for dyld.
507  */
508 static int
exec_save_path(struct image_params * imgp,user_addr_t path,int seg,const char ** excpath)509 exec_save_path(struct image_params *imgp, user_addr_t path, int seg, const char **excpath)
510 {
511 	int error;
512 	size_t len;
513 	char *kpath;
514 
515 	// imgp->ip_strings can come out of a cache, so we need to obliterate the
516 	// old path.
517 	memset(imgp->ip_strings, '\0', strlen(EXECUTABLE_KEY) + MAXPATHLEN);
518 
519 	len = MIN(MAXPATHLEN, imgp->ip_strspace);
520 
521 	switch (seg) {
522 	case UIO_USERSPACE32:
523 	case UIO_USERSPACE64:   /* Same for copyin()... */
524 		error = copyinstr(path, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
525 		break;
526 	case UIO_SYSSPACE:
527 		kpath = CAST_DOWN(char *, path); /* SAFE */
528 		error = copystr(kpath, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
529 		break;
530 	default:
531 		error = EFAULT;
532 		break;
533 	}
534 
535 	if (!error) {
536 		bcopy(EXECUTABLE_KEY, imgp->ip_strings, strlen(EXECUTABLE_KEY));
537 		len += strlen(EXECUTABLE_KEY);
538 
539 		imgp->ip_strendp += len;
540 		imgp->ip_strspace -= len;
541 
542 		if (excpath) {
543 			*excpath = imgp->ip_strings + strlen(EXECUTABLE_KEY);
544 		}
545 	}
546 
547 	return error;
548 }
549 
550 /*
551  * exec_reset_save_path
552  *
553  * If we detect a shell script, we need to reset the string area
554  * state so that the interpreter can be saved onto the stack.
555  *
556  * Parameters;	struct image_params *		image parameter block
557  *
558  * Returns:	int			0	Success
559  *
560  * Implicit returns:
561  *		(imgp->ip_strings)		saved path
562  *		(imgp->ip_strspace)		space remaining in ip_strings
563  *		(imgp->ip_strendp)		start of remaining copy area
564  *		(imgp->ip_argspace)		space remaining of NCARGS
565  *
566  */
567 static int
exec_reset_save_path(struct image_params * imgp)568 exec_reset_save_path(struct image_params *imgp)
569 {
570 	imgp->ip_strendp = imgp->ip_strings;
571 	imgp->ip_argspace = NCARGS;
572 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
573 
574 	return 0;
575 }
576 
577 /*
578  * exec_shell_imgact
579  *
580  * Image activator for interpreter scripts.  If the image begins with
581  * the characters "#!", then it is an interpreter script.  Verify the
582  * length of the script line indicating the interpreter is not in
583  * excess of the maximum allowed size.  If this is the case, then
584  * break out the arguments, if any, which are separated by white
585  * space, and copy them into the argument save area as if they were
586  * provided on the command line before all other arguments.  The line
587  * ends when we encounter a comment character ('#') or newline.
588  *
589  * Parameters;	struct image_params *	image parameter block
590  *
591  * Returns:	-1			not an interpreter (keep looking)
592  *		-3			Success: interpreter: relookup
593  *		>0			Failure: interpreter: error number
594  *
595  * A return value other than -1 indicates subsequent image activators should
596  * not be given the opportunity to attempt to activate the image.
597  */
598 static int
exec_shell_imgact(struct image_params * imgp)599 exec_shell_imgact(struct image_params *imgp)
600 {
601 	char *vdata = imgp->ip_vdata;
602 	char *ihp;
603 	char *line_startp, *line_endp;
604 	char *interp;
605 
606 	/*
607 	 * Make sure it's a shell script.  If we've already redirected
608 	 * from an interpreted file once, don't do it again.
609 	 */
610 	if (vdata[0] != '#' ||
611 	    vdata[1] != '!' ||
612 	    (imgp->ip_flags & IMGPF_INTERPRET) != 0) {
613 		return -1;
614 	}
615 
616 	if (imgp->ip_origcputype != 0) {
617 		/* Fat header previously matched, don't allow shell script inside */
618 		return -1;
619 	}
620 
621 	imgp->ip_flags |= IMGPF_INTERPRET;
622 	imgp->ip_interp_sugid_fd = -1;
623 	imgp->ip_interp_buffer[0] = '\0';
624 
625 	/* Check to see if SUGID scripts are permitted.  If they aren't then
626 	 * clear the SUGID bits.
627 	 * imgp->ip_vattr is known to be valid.
628 	 */
629 	if (sugid_scripts == 0) {
630 		imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
631 	}
632 
633 	/* Try to find the first non-whitespace character */
634 	for (ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++) {
635 		if (IS_EOL(*ihp)) {
636 			/* Did not find interpreter, "#!\n" */
637 			return ENOEXEC;
638 		} else if (IS_WHITESPACE(*ihp)) {
639 			/* Whitespace, like "#!    /bin/sh\n", keep going. */
640 		} else {
641 			/* Found start of interpreter */
642 			break;
643 		}
644 	}
645 
646 	if (ihp == &vdata[IMG_SHSIZE]) {
647 		/* All whitespace, like "#!           " */
648 		return ENOEXEC;
649 	}
650 
651 	line_startp = ihp;
652 
653 	/* Try to find the end of the interpreter+args string */
654 	for (; ihp < &vdata[IMG_SHSIZE]; ihp++) {
655 		if (IS_EOL(*ihp)) {
656 			/* Got it */
657 			break;
658 		} else {
659 			/* Still part of interpreter or args */
660 		}
661 	}
662 
663 	if (ihp == &vdata[IMG_SHSIZE]) {
664 		/* A long line, like "#! blah blah blah" without end */
665 		return ENOEXEC;
666 	}
667 
668 	/* Backtrack until we find the last non-whitespace */
669 	while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
670 		ihp--;
671 	}
672 
673 	/* The character after the last non-whitespace is our logical end of line */
674 	line_endp = ihp + 1;
675 
676 	/*
677 	 * Now we have pointers to the usable part of:
678 	 *
679 	 * "#!  /usr/bin/int first    second   third    \n"
680 	 *      ^ line_startp                       ^ line_endp
681 	 */
682 
683 	/* copy the interpreter name */
684 	interp = imgp->ip_interp_buffer;
685 	for (ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++) {
686 		*interp++ = *ihp;
687 	}
688 	*interp = '\0';
689 
690 	exec_reset_save_path(imgp);
691 	exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
692 	    UIO_SYSSPACE, NULL);
693 
694 	/* Copy the entire interpreter + args for later processing into argv[] */
695 	interp = imgp->ip_interp_buffer;
696 	for (ihp = line_startp; (ihp < line_endp); ihp++) {
697 		*interp++ = *ihp;
698 	}
699 	*interp = '\0';
700 
701 #if CONFIG_SETUID
702 	/*
703 	 * If we have an SUID or SGID script, create a file descriptor
704 	 * from the vnode and pass /dev/fd/%d instead of the actual
705 	 * path name so that the script does not get opened twice
706 	 */
707 	if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
708 		proc_t p;
709 		struct fileproc *fp;
710 		int fd;
711 		int error;
712 
713 		p = vfs_context_proc(imgp->ip_vfs_context);
714 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &fd);
715 		if (error) {
716 			return error;
717 		}
718 
719 		fp->fp_glob->fg_flag = FREAD;
720 		fp->fp_glob->fg_ops = &vnops;
721 		fp_set_data(fp, imgp->ip_vp);
722 
723 		proc_fdlock(p);
724 		procfdtbl_releasefd(p, fd, NULL);
725 		fp_drop(p, fd, fp, 1);
726 		proc_fdunlock(p);
727 		vnode_ref(imgp->ip_vp);
728 
729 		imgp->ip_interp_sugid_fd = fd;
730 	}
731 #endif /* CONFIG_SETUID */
732 
733 	return -3;
734 }
735 
736 
737 
738 /*
739  * exec_fat_imgact
740  *
741  * Image activator for fat 1.0 binaries.  If the binary is fat, then we
742  * need to select an image from it internally, and make that the image
743  * we are going to attempt to execute.  At present, this consists of
744  * reloading the first page for the image with a first page from the
745  * offset location indicated by the fat header.
746  *
747  * Parameters;	struct image_params *	image parameter block
748  *
749  * Returns:	-1			not a fat binary (keep looking)
750  *		-2			Success: encapsulated binary: reread
751  *		>0			Failure: error number
752  *
753  * Important:	This image activator is byte order neutral.
754  *
755  * Note:	A return value other than -1 indicates subsequent image
756  *		activators should not be given the opportunity to attempt
757  *		to activate the image.
758  *
759  *              If we find an encapsulated binary, we make no assertions
760  *		about its  validity; instead, we leave that up to a rescan
761  *		for an activator to claim it, and, if it is claimed by one,
762  *		that activator is responsible for determining validity.
763  */
764 static int
exec_fat_imgact(struct image_params * imgp)765 exec_fat_imgact(struct image_params *imgp)
766 {
767 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
768 	kauth_cred_t cred = kauth_cred_proc_ref(p);
769 	struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
770 	struct _posix_spawnattr *psa = NULL;
771 	struct fat_arch fat_arch;
772 	int resid, error;
773 	load_return_t lret;
774 
775 	if (imgp->ip_origcputype != 0) {
776 		/* Fat header previously matched, don't allow another fat file inside */
777 		error = -1; /* not claimed */
778 		goto bad;
779 	}
780 
781 	/* Make sure it's a fat binary */
782 	if (OSSwapBigToHostInt32(fat_header->magic) != FAT_MAGIC) {
783 		error = -1; /* not claimed */
784 		goto bad;
785 	}
786 
787 	/* imgp->ip_vdata has PAGE_SIZE, zerofilled if the file is smaller */
788 	lret = fatfile_validate_fatarches((vm_offset_t)fat_header, PAGE_SIZE,
789 	    (off_t)imgp->ip_vattr->va_data_size);
790 	if (lret != LOAD_SUCCESS) {
791 		error = load_return_to_errno(lret);
792 		goto bad;
793 	}
794 
795 	/* If posix_spawn binprefs exist, respect those prefs. */
796 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
797 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
798 		uint32_t pr = 0;
799 
800 		/* Check each preference listed against all arches in header */
801 		for (pr = 0; pr < NBINPREFS; pr++) {
802 			cpu_type_t pref = psa->psa_binprefs[pr];
803 			cpu_type_t subpref = psa->psa_subcpuprefs[pr];
804 
805 			if (pref == 0) {
806 				/* No suitable arch in the pref list */
807 				error = EBADARCH;
808 				goto bad;
809 			}
810 
811 			if (pref == CPU_TYPE_ANY) {
812 				/* Fall through to regular grading */
813 				goto regular_grading;
814 			}
815 
816 			lret = fatfile_getbestarch_for_cputype(pref,
817 			    subpref,
818 			    (vm_offset_t)fat_header,
819 			    PAGE_SIZE,
820 			    imgp,
821 			    &fat_arch);
822 			if (lret == LOAD_SUCCESS) {
823 				goto use_arch;
824 			}
825 		}
826 
827 		/* Requested binary preference was not honored */
828 		error = EBADEXEC;
829 		goto bad;
830 	}
831 
832 regular_grading:
833 	/* Look up our preferred architecture in the fat file. */
834 	lret = fatfile_getbestarch((vm_offset_t)fat_header,
835 	    PAGE_SIZE,
836 	    imgp,
837 	    &fat_arch,
838 	    (p->p_flag & P_AFFINITY) != 0);
839 	if (lret != LOAD_SUCCESS) {
840 		error = load_return_to_errno(lret);
841 		goto bad;
842 	}
843 
844 use_arch:
845 	/* Read the Mach-O header out of fat_arch */
846 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
847 	    PAGE_SIZE, fat_arch.offset,
848 	    UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
849 	    cred, &resid, p);
850 	if (error) {
851 		goto bad;
852 	}
853 
854 	if (resid) {
855 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
856 	}
857 
858 	/* Success.  Indicate we have identified an encapsulated binary */
859 	error = -2;
860 	imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
861 	imgp->ip_arch_size = (user_size_t)fat_arch.size;
862 	imgp->ip_origcputype = fat_arch.cputype;
863 	imgp->ip_origcpusubtype = fat_arch.cpusubtype;
864 
865 bad:
866 	kauth_cred_unref(&cred);
867 	return error;
868 }
869 
870 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)871 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
872 {
873 	int ret;
874 
875 	(void)task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0);
876 	task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
877 	if (result->is_64bit_addr) {
878 		OSBitOrAtomic(P_LP64, &p->p_flag);
879 		get_bsdthread_info(thread)->uu_flag |= UT_LP64;
880 	} else {
881 		OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
882 		get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
883 	}
884 	task_set_mach_header_address(task, result->mach_header);
885 
886 	ret = thread_state_initialize(thread);
887 	if (ret != KERN_SUCCESS) {
888 		return ret;
889 	}
890 
891 	if (result->threadstate) {
892 		uint32_t *ts = result->threadstate;
893 		uint32_t total_size = (uint32_t)result->threadstate_sz;
894 
895 		while (total_size > 0) {
896 			uint32_t flavor = *ts++;
897 			uint32_t size = *ts++;
898 
899 			ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
900 			if (ret) {
901 				return ret;
902 			}
903 			ts += size;
904 			total_size -= (size + 2) * sizeof(uint32_t);
905 		}
906 	}
907 
908 	thread_setentrypoint(thread, result->entry_point);
909 
910 	return KERN_SUCCESS;
911 }
912 
913 #if (DEVELOPMENT || DEBUG)
914 extern char panic_on_proc_crash[];
915 extern int use_panic_on_proc_crash;
916 
917 extern char panic_on_proc_exit[];
918 extern int use_panic_on_proc_exit;
919 
920 extern char panic_on_proc_spawn_fail[];
921 extern int use_panic_on_proc_spawn_fail;
922 #endif
923 
924 void
set_proc_name(struct image_params * imgp,proc_t p)925 set_proc_name(struct image_params *imgp, proc_t p)
926 {
927 	int p_name_len = sizeof(p->p_name) - 1;
928 
929 	if (imgp->ip_ndp->ni_cnd.cn_namelen > p_name_len) {
930 		imgp->ip_ndp->ni_cnd.cn_namelen = p_name_len;
931 	}
932 
933 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name,
934 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
935 	p->p_name[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
936 
937 	if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN) {
938 		imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
939 	}
940 
941 	bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
942 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
943 	p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
944 
945 #if DEVELOPMENT || DEBUG
946 	/*
947 	 * This happens during image activation, so the crash behavior flags from
948 	 * posix_spawn will have already been set. So we don't have to worry about
949 	 * this being overridden.
950 	 */
951 	if (use_panic_on_proc_crash && strcmp(p->p_comm, panic_on_proc_crash) == 0) {
952 		printf("will panic on proc crash: %s\n", p->p_comm);
953 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_CRASH;
954 	}
955 
956 	if (use_panic_on_proc_exit && strcmp(p->p_comm, panic_on_proc_exit) == 0) {
957 		printf("will panic on proc exit: %s\n", p->p_comm);
958 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_EXIT;
959 	}
960 
961 	if (use_panic_on_proc_spawn_fail && strcmp(p->p_comm, panic_on_proc_spawn_fail) == 0) {
962 		printf("will panic on proc spawn fail: %s\n", p->p_comm);
963 		p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_SPAWN_FAIL;
964 	}
965 #endif
966 }
967 
968 #if __has_feature(ptrauth_calls)
969 /**
970  * Returns a team ID string that may be used to assign a shared region.
971  *
972  * Platform binaries do not have team IDs and will return NULL.  Non-platform
973  * binaries without a team ID will be assigned an artificial team ID of ""
974  * (empty string) so that they will not be assigned to the default shared
975  * region.
976  *
977  * @param imgp image parameter block
978  * @return NULL if this is a platform binary, or an appropriate team ID string
979  *         otherwise
980  */
981 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)982 get_teamid_for_shared_region(struct image_params *imgp)
983 {
984 	assert(imgp->ip_vp != NULL);
985 
986 	const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
987 	if (ret) {
988 		return ret;
989 	}
990 
991 	struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
992 	if (csblob_get_platform_binary(blob)) {
993 		return NULL;
994 	} else {
995 		static const char *NO_TEAM_ID = "";
996 		return NO_TEAM_ID;
997 	}
998 }
999 
1000 /**
1001  * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
1002  *
1003  * @param cpusubtype Mach-O style CPU subtype
1004  * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
1005  */
1006 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)1007 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
1008 {
1009 	return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1010 	       CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
1011 }
1012 
1013 #endif /* __has_feature(ptrauth_calls) */
1014 
1015 /**
1016  * Returns whether a type/subtype slice matches the requested
1017  * type/subtype.
1018  *
1019  * @param mask Bits to mask from the requested/tested cpu type
1020  * @param req_cpu Requested cpu type
1021  * @param req_subcpu Requested cpu subtype
1022  * @param test_cpu Tested slice cpu type
1023  * @param test_subcpu Tested slice cpu subtype
1024  */
1025 boolean_t
binary_match(cpu_type_t mask,cpu_type_t req_cpu,cpu_subtype_t req_subcpu,cpu_type_t test_cpu,cpu_subtype_t test_subcpu)1026 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
1027     cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
1028     cpu_subtype_t test_subcpu)
1029 {
1030 	if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
1031 		return FALSE;
1032 	}
1033 
1034 	test_subcpu &= ~CPU_SUBTYPE_MASK;
1035 	req_subcpu  &= ~CPU_SUBTYPE_MASK;
1036 
1037 	if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
1038 		return FALSE;
1039 	}
1040 
1041 	return TRUE;
1042 }
1043 
1044 
1045 #define MIN_IOS_TPRO_SDK_VERSION        0x00100000
1046 #define MIN_OSX_TPRO_SDK_VERSION        0x000D0000
1047 #define MIN_TVOS_TPRO_SDK_VERSION       0x000D0000
1048 #define MIN_WATCHOS_TPRO_SDK_VERSION    0x00090000
1049 #define MIN_DRIVERKIT_TPRO_SDK_VERSION  0x00600000
1050 
1051 static void
exec_setup_tpro(struct image_params * imgp,load_result_t * load_result)1052 exec_setup_tpro(struct image_params *imgp, load_result_t *load_result)
1053 {
1054 	extern boolean_t xprr_tpro_enabled;
1055 	extern boolean_t enable_user_modifiable_perms;
1056 	uint32_t min_sdk_version = 0;
1057 
1058 	/* x86-64 translated code cannot take advantage of TPRO */
1059 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1060 		return;
1061 	}
1062 
1063 	/* Do not enable on 32-bit VA targets */
1064 	if (!(imgp->ip_flags & IMGPF_IS_64BIT_ADDR)) {
1065 		return;
1066 	}
1067 
1068 	switch (load_result->ip_platform) {
1069 	case PLATFORM_IOS:
1070 	case PLATFORM_IOSSIMULATOR:
1071 	case PLATFORM_MACCATALYST:
1072 		min_sdk_version = MIN_IOS_TPRO_SDK_VERSION;
1073 		break;
1074 	case PLATFORM_MACOS:
1075 		min_sdk_version = MIN_OSX_TPRO_SDK_VERSION;
1076 		break;
1077 	case PLATFORM_TVOS:
1078 	case PLATFORM_TVOSSIMULATOR:
1079 		min_sdk_version = MIN_TVOS_TPRO_SDK_VERSION;
1080 		break;
1081 	case PLATFORM_WATCHOS:
1082 	case PLATFORM_WATCHOSSIMULATOR:
1083 		min_sdk_version = MIN_WATCHOS_TPRO_SDK_VERSION;
1084 		break;
1085 	case PLATFORM_DRIVERKIT:
1086 		min_sdk_version = MIN_DRIVERKIT_TPRO_SDK_VERSION;
1087 		break;
1088 	default:
1089 		/* TPRO is on by default for newer platforms */
1090 		break;
1091 	}
1092 
1093 }
1094 
1095 /*
1096  * If the passed in executable's vnode should use the RSR
1097  * shared region, then this should return TRUE, otherwise, return FALSE.
1098  */
1099 static uint32_t rsr_current_version = 0;
1100 boolean_t (*rsr_check_vnode)(void *vnode) = NULL;
1101 
1102 boolean_t
vnode_is_rsr(vnode_t vp)1103 vnode_is_rsr(vnode_t vp)
1104 {
1105 	if (!(vnode_isreg(vp) && vnode_tag(vp) == VT_APFS)) {
1106 		return FALSE;
1107 	}
1108 
1109 	if (rsr_check_vnode != NULL && rsr_check_vnode((void *)vp)) {
1110 		return TRUE;
1111 	}
1112 	return FALSE;
1113 }
1114 
1115 
1116 static inline void
encode_HR_entitlement(const char * entitlement,HR_flags_t mask,const struct image_params * imgp,load_result_t * load_result)1117 encode_HR_entitlement(const char *entitlement, HR_flags_t mask,
1118     const struct image_params *imgp, load_result_t *load_result)
1119 {
1120 	if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
1121 		load_result->hardened_runtime_binary |= mask;
1122 	}
1123 }
1124 
1125 uint32_t
rsr_get_version(void)1126 rsr_get_version(void)
1127 {
1128 	return os_atomic_load(&rsr_current_version, relaxed);
1129 }
1130 
1131 void
rsr_bump_version(void)1132 rsr_bump_version(void)
1133 {
1134 	os_atomic_inc(&rsr_current_version, relaxed);
1135 }
1136 
1137 #if XNU_TARGET_OS_OSX
1138 static int
1139 rsr_version_sysctl SYSCTL_HANDLER_ARGS
1140 {
1141 #pragma unused(arg1, arg2, oidp)
1142 	int value = rsr_get_version();
1143 	int error = SYSCTL_OUT(req, &value, sizeof(int));
1144 	if (error) {
1145 		return error;
1146 	}
1147 
1148 	if (!req->newptr) {
1149 		return 0;
1150 	}
1151 
1152 	error = SYSCTL_IN(req, &value, sizeof(int));
1153 	if (error) {
1154 		return error;
1155 	}
1156 	if (value != 0) {
1157 		rsr_bump_version();
1158 	}
1159 	return 0;
1160 }
1161 
1162 
1163 SYSCTL_PROC(_vm, OID_AUTO, shared_region_control,
1164     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
1165     0, 0, rsr_version_sysctl, "I", "");
1166 #endif /* XNU_TARGET_OS_OSX */
1167 
1168 /*
1169  * exec_mach_imgact
1170  *
1171  * Image activator for mach-o 1.0 binaries.
1172  *
1173  * Parameters;	struct image_params *	image parameter block
1174  *
1175  * Returns:	-1			not a fat binary (keep looking)
1176  *		-2			Success: encapsulated binary: reread
1177  *		>0			Failure: error number
1178  *		EBADARCH		Mach-o binary, but with an unrecognized
1179  *					architecture
1180  *		ENOMEM			No memory for child process after -
1181  *					can only happen after vfork()
1182  *
1183  * Important:	This image activator is NOT byte order neutral.
1184  *
1185  * Note:	A return value other than -1 indicates subsequent image
1186  *		activators should not be given the opportunity to attempt
1187  *		to activate the image.
1188  */
1189 static int
exec_mach_imgact(struct image_params * imgp)1190 exec_mach_imgact(struct image_params *imgp)
1191 {
1192 	struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1193 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
1194 	int                     error = 0;
1195 	task_t                  task;
1196 	task_t                  new_task = NULL; /* protected by vfexec */
1197 	thread_t                thread;
1198 	struct uthread          *uthread;
1199 	vm_map_t old_map = VM_MAP_NULL;
1200 	vm_map_t map = VM_MAP_NULL;
1201 	load_return_t           lret;
1202 	load_result_t           load_result = {};
1203 	struct _posix_spawnattr *psa = NULL;
1204 	int                     spawn = (imgp->ip_flags & IMGPF_SPAWN);
1205 	const int               vfexec = 0;
1206 	int                     exec = (imgp->ip_flags & IMGPF_EXEC);
1207 	os_reason_t             exec_failure_reason = OS_REASON_NULL;
1208 	boolean_t               reslide = FALSE;
1209 	char *                  userspace_coredump_name = NULL;
1210 
1211 	/*
1212 	 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1213 	 * is a reserved field on the end, so for the most part, we can
1214 	 * treat them as if they were identical. Reverse-endian Mach-O
1215 	 * binaries are recognized but not compatible.
1216 	 */
1217 	if ((mach_header->magic == MH_CIGAM) ||
1218 	    (mach_header->magic == MH_CIGAM_64)) {
1219 		error = EBADARCH;
1220 		goto bad;
1221 	}
1222 
1223 	if ((mach_header->magic != MH_MAGIC) &&
1224 	    (mach_header->magic != MH_MAGIC_64)) {
1225 		error = -1;
1226 		goto bad;
1227 	}
1228 
1229 	if (mach_header->filetype != MH_EXECUTE) {
1230 		error = -1;
1231 		goto bad;
1232 	}
1233 
1234 	if (imgp->ip_origcputype != 0) {
1235 		/* Fat header previously had an idea about this thin file */
1236 		if (imgp->ip_origcputype != mach_header->cputype ||
1237 		    imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1238 			error = EBADARCH;
1239 			goto bad;
1240 		}
1241 	} else {
1242 		imgp->ip_origcputype = mach_header->cputype;
1243 		imgp->ip_origcpusubtype = mach_header->cpusubtype;
1244 	}
1245 
1246 	task = current_task();
1247 	thread = current_thread();
1248 	uthread = get_bsdthread_info(thread);
1249 
1250 	if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1251 		imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1252 	}
1253 
1254 
1255 	/* If posix_spawn binprefs exist, respect those prefs. */
1256 	psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1257 	if (psa != NULL && psa->psa_binprefs[0] != 0) {
1258 		int pr = 0;
1259 		for (pr = 0; pr < NBINPREFS; pr++) {
1260 			cpu_type_t pref = psa->psa_binprefs[pr];
1261 			cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1262 
1263 			if (pref == 0) {
1264 				/* No suitable arch in the pref list */
1265 				error = EBADARCH;
1266 				goto bad;
1267 			}
1268 
1269 			if (pref == CPU_TYPE_ANY) {
1270 				/* Jump to regular grading */
1271 				goto grade;
1272 			}
1273 
1274 			if (binary_match(CPU_ARCH_MASK, pref, subpref,
1275 			    imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1276 				goto grade;
1277 			}
1278 		}
1279 		error = EBADARCH;
1280 		goto bad;
1281 	}
1282 grade:
1283 	if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1284 	    imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1285 		error = EBADARCH;
1286 		goto bad;
1287 	}
1288 
1289 	if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1290 	    imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1291 #if __x86_64__
1292 		const char *excpath;
1293 		error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1294 		os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1295 #endif
1296 		error = EBADARCH;
1297 		goto bad;
1298 	}
1299 
1300 #if defined(HAS_APPLE_PAC)
1301 	assert(mach_header->cputype == CPU_TYPE_ARM64
1302 	    );
1303 
1304 	if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1305 	    arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1306 	    ) {
1307 		imgp->ip_flags &= ~IMGPF_NOJOP;
1308 	} else {
1309 		imgp->ip_flags |= IMGPF_NOJOP;
1310 	}
1311 #endif
1312 
1313 	/* Copy in arguments/environment from the old process */
1314 	error = exec_extract_strings(imgp);
1315 	if (error) {
1316 		goto bad;
1317 	}
1318 
1319 	AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1320 	    imgp->ip_endargv - imgp->ip_startargv);
1321 	AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1322 	    imgp->ip_endenvv - imgp->ip_endargv);
1323 
1324 
1325 
1326 	/* reset local idea of thread, uthread, task */
1327 	thread = imgp->ip_new_thread;
1328 	uthread = get_bsdthread_info(thread);
1329 	task = new_task = get_threadtask(thread);
1330 
1331 	/*
1332 	 *	Load the Mach-O file.
1333 	 *
1334 	 * NOTE: An error after this point  indicates we have potentially
1335 	 * destroyed or overwritten some process state while attempting an
1336 	 * execve() following a vfork(), which is an unrecoverable condition.
1337 	 * We send the new process an immediate SIGKILL to avoid it executing
1338 	 * any instructions in the mutated address space. For true spawns,
1339 	 * this is not the case, and "too late" is still not too late to
1340 	 * return an error code to the parent process.
1341 	 */
1342 
1343 	/*
1344 	 * Actually load the image file we previously decided to load.
1345 	 */
1346 	lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1347 	if (lret != LOAD_SUCCESS) {
1348 		error = load_return_to_errno(lret);
1349 
1350 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1351 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1352 		if (lret == LOAD_BADMACHO_UPX) {
1353 			set_proc_name(imgp, p);
1354 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1355 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1356 		} else {
1357 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1358 
1359 			if (bootarg_execfailurereports) {
1360 				set_proc_name(imgp, p);
1361 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1362 			}
1363 		}
1364 
1365 		exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1366 
1367 		goto badtoolate;
1368 	}
1369 
1370 	/*
1371 	 * ERROR RECOVERY
1372 	 *
1373 	 * load_machfile() returned the new VM map ("map") but we haven't
1374 	 * committed to it yet.
1375 	 * Any error path between here and the point where we commit to using
1376 	 * the new "map" (with swap_task_map()) should deallocate "map".
1377 	 */
1378 
1379 #ifndef KASAN
1380 	/*
1381 	 * Security: zone sanity checks on fresh boot or initproc re-exec.
1382 	 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1383 	 * which means here is the earliest point we can assert on empty service port label zone,
1384 	 * after load_machfile() above terminates old launchd's IPC space.
1385 	 *
1386 	 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1387 	 * under quarantine.
1388 	 */
1389 	if (task_pid(task) == 1) {
1390 		zone_userspace_reboot_checks();
1391 	}
1392 #endif
1393 
1394 	proc_lock(p);
1395 	p->p_cputype = imgp->ip_origcputype;
1396 	p->p_cpusubtype = imgp->ip_origcpusubtype;
1397 	proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1398 	exec_setup_tpro(imgp, &load_result);
1399 
1400 	vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1401 	vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1402 	vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1403 #if XNU_TARGET_OS_OSX
1404 	if (proc_platform(p) == PLATFORM_IOS) {
1405 		assert(vm_map_is_alien(map));
1406 	} else {
1407 		assert(!vm_map_is_alien(map));
1408 	}
1409 #endif /* XNU_TARGET_OS_OSX */
1410 	proc_unlock(p);
1411 
1412 	/*
1413 	 * Set TPRO flags if enabled
1414 	 */
1415 
1416 	/*
1417 	 * Set code-signing flags if this binary is signed, or if parent has
1418 	 * requested them on exec.
1419 	 */
1420 	if (load_result.csflags & CS_VALID) {
1421 		imgp->ip_csflags |= load_result.csflags &
1422 		    (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1423 		    CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1424 		    CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1425 		    CS_ENTITLEMENT_FLAGS |
1426 		    CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1427 	} else {
1428 		imgp->ip_csflags &= ~CS_VALID;
1429 	}
1430 
1431 	if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1432 		imgp->ip_csflags |= CS_HARD;
1433 	}
1434 	if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1435 		imgp->ip_csflags |= CS_KILL;
1436 	}
1437 	if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1438 		imgp->ip_csflags |= CS_ENFORCEMENT;
1439 	}
1440 	if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1441 		if (proc_getcsflags(p) & CS_INSTALLER) {
1442 			imgp->ip_csflags |= CS_INSTALLER;
1443 		}
1444 		if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1445 			imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1446 		}
1447 		if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1448 			imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1449 		}
1450 	}
1451 
1452 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1453 	/*
1454 	 * ptrauth version 0 is a preview ABI.  Developers can opt into running
1455 	 * their own arm64e binaries for local testing, with the understanding
1456 	 * that future OSes may break ABI.
1457 	 */
1458 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1459 	    CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1460 	    !load_result.platform_binary &&
1461 	    !bootarg_arm64e_preview_abi) {
1462 		static bool logged_once = false;
1463 		set_proc_name(imgp, p);
1464 
1465 		printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1466 		if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1467 			printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1468 		}
1469 
1470 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1471 		if (bootarg_execfailurereports) {
1472 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1473 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1474 		}
1475 
1476 		/* release new address space since we won't use it */
1477 		imgp->ip_free_map = map;
1478 		map = VM_MAP_NULL;
1479 		goto badtoolate;
1480 	}
1481 
1482 	if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1483 	    imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1484 	    load_result.platform_binary &&
1485 	    (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1486 		set_proc_name(imgp, p);
1487 		printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
1488 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1489 		if (bootarg_execfailurereports) {
1490 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1491 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1492 		}
1493 
1494 		/* release new address space since we won't use it */
1495 		imgp->ip_free_map = map;
1496 		map = VM_MAP_NULL;
1497 		goto badtoolate;
1498 	}
1499 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1500 
1501 
1502 	load_result.hardened_runtime_binary = 0;
1503 	// Propogate which hardened runtime entitlements are active to the apple array
1504 	encode_HR_entitlement(kCSWebBrowserHostEntitlement, BrowserHostEntitlementMask, imgp, &load_result);
1505 	encode_HR_entitlement(kCSWebBrowserGPUEntitlement, BrowserGPUEntitlementMask, imgp, &load_result);
1506 	encode_HR_entitlement(kCSWebBrowserNetworkEntitlement, BrowserNetworkEntitlementMask, imgp, &load_result);
1507 	encode_HR_entitlement(kCSWebBrowserWebContentEntitlement, BrowserWebContentEntitlementMask, imgp, &load_result);
1508 
1509 	/*
1510 	 * Set up the shared cache region in the new process.
1511 	 *
1512 	 * Normally there is a single shared region per architecture.
1513 	 * However on systems with Pointer Authentication, we can create
1514 	 * multiple shared caches with the amount of sharing determined
1515 	 * by team-id or entitlement. Inherited shared region IDs are used
1516 	 * for system processes that need to match and be able to inspect
1517 	 * a pre-existing task.
1518 	 */
1519 	int cpu_subtype = 0; /* all cpu_subtypes use the same shared region */
1520 #if __has_feature(ptrauth_calls)
1521 	char *shared_region_id = NULL;
1522 	size_t len;
1523 	char *base;
1524 	const char *cbase;
1525 #define HARDENED_RUNTIME_CONTENT_ID "C-"
1526 #define TEAM_ID_PREFIX "T-"
1527 #define ENTITLE_PREFIX "E-"
1528 #define SR_PREFIX_LEN  2
1529 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1530 
1531 	if (cpu_type() == CPU_TYPE_ARM64 &&
1532 	    arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1533 	    (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1534 		assertf(p->p_cputype == CPU_TYPE_ARM64,
1535 		    "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1536 		    p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1537 
1538 		/*
1539 		 * arm64e uses pointer authentication, so request a separate
1540 		 * shared region for this CPU subtype.
1541 		 */
1542 		cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1543 
1544 		/*
1545 		 * Determine which shared cache to select based on being told,
1546 		 * matching a team-id or matching an entitlement.
1547 		 */
1548 		if (load_result.hardened_runtime_binary & BrowserWebContentEntitlementMask) {
1549 			len = sizeof(HARDENED_RUNTIME_CONTENT_ID);
1550 			shared_region_id = kalloc_data(len, Z_WAITOK | Z_NOFAIL);
1551 			strlcpy(shared_region_id, HARDENED_RUNTIME_CONTENT_ID, len);
1552 		} else if (imgp->ip_inherited_shared_region_id) {
1553 			len = strlen(imgp->ip_inherited_shared_region_id);
1554 			shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1555 			memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1556 		} else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1557 			len = strlen(cbase);
1558 			if (vm_shared_region_per_team_id) {
1559 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1560 				    Z_WAITOK | Z_NOFAIL);
1561 				memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1562 				memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1563 			}
1564 		} else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1565 		    (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1566 			len = strlen(base);
1567 			if (vm_shared_region_by_entitlement) {
1568 				shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1569 				    Z_WAITOK | Z_NOFAIL);
1570 				memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1571 				memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1572 			}
1573 			/* Discard the copy of the entitlement */
1574 			kfree_data(base, len + 1);
1575 		}
1576 	}
1577 
1578 	if (imgp->ip_flags & IMGPF_RESLIDE) {
1579 		reslide = TRUE;
1580 	}
1581 
1582 	/* use "" as the default shared_region_id */
1583 	if (shared_region_id == NULL) {
1584 		shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1585 	}
1586 
1587 	/* ensure there's a unique pointer signing key for this shared_region_id */
1588 	shared_region_key_alloc(shared_region_id,
1589 	    imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1590 	task_set_shared_region_id(task, shared_region_id);
1591 	shared_region_id = NULL;
1592 #endif /* __has_feature(ptrauth_calls) */
1593 
1594 #if CONFIG_ROSETTA
1595 	if (imgp->ip_flags & IMGPF_ROSETTA) {
1596 		OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
1597 	} else if (p->p_flag & P_TRANSLATED) {
1598 		OSBitAndAtomic(~P_TRANSLATED, &p->p_flag);
1599 	}
1600 #endif
1601 
1602 	int cputype = cpu_type();
1603 
1604 	uint32_t rsr_version = 0;
1605 #if XNU_TARGET_OS_OSX
1606 	if (vnode_is_rsr(imgp->ip_vp)) {
1607 		rsr_version = rsr_get_version();
1608 		os_atomic_or(&p->p_ladvflag, P_RSR, relaxed);
1609 		os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_ALTLINK, relaxed);
1610 	}
1611 #endif /* XNU_TARGET_OS_OSX */
1612 
1613 	vm_map_exec(map, task, load_result.is_64bit_addr,
1614 	    (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide,
1615 	    (imgp->ip_flags & IMGPF_DRIVER) != 0,
1616 	    rsr_version);
1617 
1618 	/*
1619 	 * Close file descriptors which specify close-on-exec.
1620 	 */
1621 	fdt_exec(p, vfs_context_ucred(imgp->ip_vfs_context),
1622 	    psa != NULL ? psa->psa_flags : 0, imgp->ip_new_thread, exec);
1623 
1624 	/*
1625 	 * deal with set[ug]id.
1626 	 */
1627 	error = exec_handle_sugid(imgp);
1628 	if (error) {
1629 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1630 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1631 
1632 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1633 		if (bootarg_execfailurereports) {
1634 			set_proc_name(imgp, p);
1635 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1636 		}
1637 
1638 		/* release new address space since we won't use it */
1639 		imgp->ip_free_map = map;
1640 		map = VM_MAP_NULL;
1641 		goto badtoolate;
1642 	}
1643 
1644 	/*
1645 	 * Commit to new map.
1646 	 *
1647 	 * Swap the new map for the old for target task, which consumes
1648 	 * our new map reference but each leaves us responsible for the
1649 	 * old_map reference.  That lets us get off the pmap associated
1650 	 * with it, and then we can release it.
1651 	 *
1652 	 * The map needs to be set on the target task which is different
1653 	 * than current task, thus swap_task_map is used instead of
1654 	 * vm_map_switch.
1655 	 */
1656 	old_map = swap_task_map(task, thread, map);
1657 #if MACH_ASSERT
1658 	/*
1659 	 * Reset the pmap's process info to prevent ledger checks
1660 	 * which might fail due to the ledgers being shared between
1661 	 * the old and new pmaps.
1662 	 */
1663 	vm_map_pmap_set_process(old_map, -1, "<old_map>");
1664 #endif /* MACH_ASSERT */
1665 	imgp->ip_free_map = old_map;
1666 	old_map = NULL;
1667 
1668 	lret = activate_exec_state(task, p, thread, &load_result);
1669 	if (lret != KERN_SUCCESS) {
1670 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1671 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1672 
1673 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1674 		if (bootarg_execfailurereports) {
1675 			set_proc_name(imgp, p);
1676 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1677 		}
1678 
1679 		goto badtoolate;
1680 	}
1681 
1682 	/*
1683 	 * deal with voucher on exec-calling thread.
1684 	 */
1685 	if (imgp->ip_new_thread == NULL) {
1686 		thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1687 	}
1688 
1689 	/* Make sure we won't interrupt ourself signalling a partial process */
1690 	if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1691 		psignal(p, SIGTRAP);
1692 	}
1693 
1694 	if (load_result.unixproc &&
1695 	    create_unix_stack(get_task_map(task),
1696 	    &load_result,
1697 	    p) != KERN_SUCCESS) {
1698 		error = load_return_to_errno(LOAD_NOSPACE);
1699 
1700 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1701 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1702 
1703 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1704 		if (bootarg_execfailurereports) {
1705 			set_proc_name(imgp, p);
1706 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1707 		}
1708 
1709 		goto badtoolate;
1710 	}
1711 
1712 	if (load_result.hardened_runtime_binary) {
1713 		if (cs_debug) {
1714 			printf("setting hardened runtime with entitlement mask= "
1715 			    "0x%x on task: pid = %d\n",
1716 			    load_result.hardened_runtime_binary,
1717 			    proc_getpid(p));
1718 		}
1719 		task_set_hardened_runtime(task, true);
1720 	}
1721 
1722 	/*
1723 	 * The load result will have already been munged by AMFI to include the
1724 	 * platform binary flag if boot-args dictated it (AMFI will mark anything
1725 	 * that doesn't go through the upcall path as a platform binary if its
1726 	 * enforcement is disabled).
1727 	 */
1728 	if (load_result.platform_binary) {
1729 		if (cs_debug) {
1730 			printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1731 		}
1732 
1733 		/*
1734 		 * We must use 'task' here because the proc's task has not yet been
1735 		 * switched to the new one.
1736 		 */
1737 		task_set_platform_binary(task, TRUE);
1738 	} else {
1739 		if (cs_debug) {
1740 			printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1741 		}
1742 
1743 		task_set_platform_binary(task, FALSE);
1744 	}
1745 
1746 #if XNU_TARGET_OS_OSX
1747 	/* Disable mach hardening for all 1P tasks which load 3P plugins */
1748 	if (imgp->ip_flags & IMGPF_3P_PLUGINS) {
1749 		if (cs_debug) {
1750 			printf("Disabling some mach hardening on task due to 3P plugins: pid = %d\n", proc_getpid(p));
1751 		}
1752 		task_disable_mach_hardening(task);
1753 	}
1754 #if DEVELOPMENT || DEBUG
1755 	/* Disable mach hardening for all tasks if amfi_get_out_of_my_way is set.
1756 	 * Customers will have to turn SIP off to use this boot-arg, and so this is
1757 	 * only needed internally since we disable this feature when SIP is off. */
1758 	if (AMFI_bootarg_disable_mach_hardening) {
1759 		if (cs_debug) {
1760 			printf("Disabling some mach hardening on task due to AMFI boot-args: pid = %d\n", proc_getpid(p));
1761 		}
1762 		task_disable_mach_hardening(task);
1763 	}
1764 #endif /* DEVELOPMENT || DEBUG */
1765 #endif /* XNU_TARGET_OS_OSX */
1766 
1767 	/*
1768 	 * Set starting EXC_GUARD and control port behavior for task now that
1769 	 * platform and hardened runtime is set. Use the name directly from imgp since we haven't
1770 	 * set_proc_name() yet. Also make control port for the task and main thread
1771 	 * immovable/pinned based on task's option.
1772 	 *
1773 	 * Must happen before main thread port copyout in exc_add_apple_strings.
1774 	 */
1775 	task_set_exc_guard_ctrl_port_default(task, thread,
1776 	    imgp->ip_ndp->ni_cnd.cn_nameptr,
1777 	    (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1778 	    proc_is_simulated(p),
1779 	    load_result.ip_platform,
1780 	    load_result.lr_sdk);
1781 
1782 	error = exec_add_apple_strings(imgp, &load_result); /* copies out main thread port */
1783 
1784 	if (error) {
1785 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1786 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
1787 
1788 		exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
1789 		if (bootarg_execfailurereports) {
1790 			set_proc_name(imgp, p);
1791 			exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1792 		}
1793 		goto badtoolate;
1794 	}
1795 
1796 	/* Switch to target task's map to copy out strings */
1797 	old_map = vm_map_switch(get_task_map(task));
1798 
1799 	if (load_result.unixproc) {
1800 		user_addr_t     ap;
1801 
1802 		/*
1803 		 * Copy the strings area out into the new process address
1804 		 * space.
1805 		 */
1806 		ap = p->user_stack;
1807 		error = exec_copyout_strings(imgp, &ap);
1808 		if (error) {
1809 			vm_map_switch(old_map);
1810 
1811 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1812 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
1813 
1814 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
1815 			if (bootarg_execfailurereports) {
1816 				set_proc_name(imgp, p);
1817 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1818 			}
1819 			goto badtoolate;
1820 		}
1821 		/* Set the stack */
1822 		thread_setuserstack(thread, ap);
1823 	}
1824 
1825 	if (load_result.dynlinker || load_result.is_rosetta) {
1826 		user_addr_t        ap;
1827 		int                     new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
1828 
1829 		/* Adjust the stack */
1830 		ap = thread_adjuserstack(thread, -new_ptr_size);
1831 		error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
1832 
1833 		if (error) {
1834 			vm_map_switch(old_map);
1835 
1836 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1837 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
1838 
1839 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
1840 			if (bootarg_execfailurereports) {
1841 				set_proc_name(imgp, p);
1842 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1843 			}
1844 			goto badtoolate;
1845 		}
1846 		error = task_set_dyld_info(task, load_result.all_image_info_addr,
1847 		    load_result.all_image_info_size);
1848 		if (error) {
1849 			vm_map_switch(old_map);
1850 
1851 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1852 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
1853 
1854 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1855 			if (bootarg_execfailurereports) {
1856 				set_proc_name(imgp, p);
1857 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1858 			}
1859 			error = EINVAL;
1860 			goto badtoolate;
1861 		}
1862 	}
1863 
1864 #if CONFIG_ROSETTA
1865 	if (load_result.is_rosetta) {
1866 		// Add an fd for the executable file for Rosetta's use
1867 		int main_binary_fd;
1868 		struct fileproc *fp;
1869 
1870 		error = falloc_exec(p, imgp->ip_vfs_context, &fp, &main_binary_fd);
1871 		if (error) {
1872 			vm_map_switch(old_map);
1873 
1874 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1875 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1876 
1877 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1878 			if (bootarg_execfailurereports) {
1879 				set_proc_name(imgp, p);
1880 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1881 			}
1882 			goto badtoolate;
1883 		}
1884 
1885 		error = VNOP_OPEN(imgp->ip_vp, FREAD, imgp->ip_vfs_context);
1886 		if (error) {
1887 			vm_map_switch(old_map);
1888 
1889 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1890 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1891 
1892 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1893 			if (bootarg_execfailurereports) {
1894 				set_proc_name(imgp, p);
1895 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1896 			}
1897 			goto cleanup_rosetta_fp;
1898 		}
1899 
1900 		fp->fp_glob->fg_flag = FREAD;
1901 		fp->fp_glob->fg_ops = &vnops;
1902 		fp_set_data(fp, imgp->ip_vp);
1903 
1904 		proc_fdlock(p);
1905 		procfdtbl_releasefd(p, main_binary_fd, NULL);
1906 		fp_drop(p, main_binary_fd, fp, 1);
1907 		proc_fdunlock(p);
1908 
1909 		vnode_ref(imgp->ip_vp);
1910 
1911 		// Pass the dyld load address, main binary fd, and dyld fd on the stack
1912 		uint64_t ap = thread_adjuserstack(thread, -24);
1913 
1914 		error = copyoutptr((user_addr_t)load_result.dynlinker_fd, ap, 8);
1915 		if (error) {
1916 			vm_map_switch(old_map);
1917 
1918 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1919 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1920 
1921 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1922 			if (bootarg_execfailurereports) {
1923 				set_proc_name(imgp, p);
1924 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1925 			}
1926 			goto cleanup_rosetta_fp;
1927 		}
1928 
1929 		error = copyoutptr(load_result.dynlinker_mach_header, ap + 8, 8);
1930 		if (error) {
1931 			vm_map_switch(old_map);
1932 
1933 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1934 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1935 
1936 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1937 			if (bootarg_execfailurereports) {
1938 				set_proc_name(imgp, p);
1939 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1940 			}
1941 			goto cleanup_rosetta_fp;
1942 		}
1943 
1944 		error = copyoutptr((user_addr_t)main_binary_fd, ap + 16, 8);
1945 		if (error) {
1946 			vm_map_switch(old_map);
1947 
1948 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1949 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1950 
1951 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1952 			if (bootarg_execfailurereports) {
1953 				set_proc_name(imgp, p);
1954 				exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1955 			}
1956 			goto cleanup_rosetta_fp;
1957 		}
1958 
1959 cleanup_rosetta_fp:
1960 		if (error) {
1961 			fp_free(p, load_result.dynlinker_fd, load_result.dynlinker_fp);
1962 			fp_free(p, main_binary_fd, fp);
1963 			goto badtoolate;
1964 		}
1965 	}
1966 
1967 #endif
1968 
1969 	/* Avoid immediate VM faults back into kernel */
1970 	exec_prefault_data(p, imgp, &load_result);
1971 
1972 	vm_map_switch(old_map);
1973 
1974 	/*
1975 	 * Reset signal state.
1976 	 */
1977 	execsigs(p, thread);
1978 
1979 	/*
1980 	 * need to cancel async IO requests that can be cancelled and wait for those
1981 	 * already active.  MAY BLOCK!
1982 	 */
1983 	_aio_exec( p );
1984 
1985 #if SYSV_SHM
1986 	/* FIXME: Till vmspace inherit is fixed: */
1987 	if (!vfexec && p->vm_shm) {
1988 		shmexec(p);
1989 	}
1990 #endif
1991 #if SYSV_SEM
1992 	/* Clean up the semaphores */
1993 	semexit(p);
1994 #endif
1995 
1996 	/*
1997 	 * Remember file name for accounting.
1998 	 */
1999 	p->p_acflag &= ~AFORK;
2000 
2001 	set_proc_name(imgp, p);
2002 
2003 #if CONFIG_SECLUDED_MEMORY
2004 	if (secluded_for_apps &&
2005 	    load_result.platform_binary) {
2006 		if (strncmp(p->p_name,
2007 		    "Camera",
2008 		    sizeof(p->p_name)) == 0) {
2009 			task_set_could_use_secluded_mem(task, TRUE);
2010 		} else {
2011 			task_set_could_use_secluded_mem(task, FALSE);
2012 		}
2013 		if (strncmp(p->p_name,
2014 		    "mediaserverd",
2015 		    sizeof(p->p_name)) == 0) {
2016 			task_set_could_also_use_secluded_mem(task, TRUE);
2017 		}
2018 	}
2019 #endif /* CONFIG_SECLUDED_MEMORY */
2020 
2021 #if __arm64__
2022 	if (load_result.legacy_footprint) {
2023 		task_set_legacy_footprint(task);
2024 	}
2025 #endif /* __arm64__ */
2026 
2027 	pal_dbg_set_task_name(task);
2028 
2029 #if DEVELOPMENT || DEBUG
2030 	/*
2031 	 * Update the pid an proc name for importance base if any
2032 	 */
2033 	task_importance_update_owner_info(task);
2034 #endif
2035 
2036 	proc_setexecutableuuid(p, &load_result.uuid[0]);
2037 
2038 #if CONFIG_DTRACE
2039 	dtrace_proc_exec(p);
2040 #endif
2041 
2042 	if (kdebug_enable) {
2043 		long args[4] = {};
2044 
2045 		uintptr_t fsid = 0, fileid = 0;
2046 		if (imgp->ip_vattr) {
2047 			uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
2048 			fsid   = (uintptr_t)fsid64;
2049 			fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
2050 			// check for (unexpected) overflow and trace zero in that case
2051 			if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
2052 				fsid = fileid = 0;
2053 			}
2054 		}
2055 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
2056 		    (uintptr_t)thread_tid(thread));
2057 
2058 		extern void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
2059 		kdebug_proc_name_args(p, args);
2060 		KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
2061 		    args[2], args[3], (uintptr_t)thread_tid(thread));
2062 	}
2063 
2064 
2065 	/*
2066 	 * If posix_spawned with the START_SUSPENDED flag, stop the
2067 	 * process before it runs.
2068 	 */
2069 	if (imgp->ip_px_sa != NULL) {
2070 		psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
2071 		if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
2072 			proc_lock(p);
2073 			p->p_stat = SSTOP;
2074 			proc_unlock(p);
2075 			(void) task_suspend_internal(task);
2076 		}
2077 	}
2078 
2079 	/*
2080 	 * mark as execed
2081 	 */
2082 	OSBitOrAtomic(P_EXEC, &p->p_flag);
2083 	proc_resetregister(p);
2084 	if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
2085 		proc_lock(p);
2086 		p->p_lflag &= ~P_LPPWAIT;
2087 		proc_unlock(p);
2088 		wakeup((caddr_t)p->p_pptr);
2089 	}
2090 
2091 	/*
2092 	 * Set up dext coredumps on kernel panic.
2093 	 * This requires the following:
2094 	 * - dext_panic_coredump=1 boot-arg (enabled by default on DEVELOPMENT, DEBUG and certain Seed builds)
2095 	 * - process must be a driver
2096 	 * - process must have the com.apple.private.enable-coredump-on-panic entitlement, and the
2097 	 *   entitlement has a string value.
2098 	 * - process must have the com.apple.private.enable-coredump-on-panic-seed-privacy-approved
2099 	 *   entitlement (Seed builds only).
2100 	 *
2101 	 * The core dump file name is formatted with the entitlement string value, followed by a hyphen
2102 	 * and the process PID.
2103 	 */
2104 	if (enable_dext_coredumps_on_panic &&
2105 	    (imgp->ip_flags & IMGPF_DRIVER) != 0 &&
2106 	    (userspace_coredump_name = IOVnodeGetEntitlement(imgp->ip_vp,
2107 	    (int64_t)imgp->ip_arch_offset, USERSPACE_COREDUMP_PANIC_ENTITLEMENT)) != NULL) {
2108 		size_t userspace_coredump_name_len = strlen(userspace_coredump_name);
2109 
2110 		char core_name[MACH_CORE_FILEHEADER_NAMELEN];
2111 		/* 16 - NULL char - strlen("-") - maximum of 5 digits for pid */
2112 		snprintf(core_name, MACH_CORE_FILEHEADER_NAMELEN, "%.9s-%d", userspace_coredump_name, proc_getpid(p));
2113 
2114 		kern_register_userspace_coredump(task, core_name);
2115 
2116 		/* Discard the copy of the entitlement */
2117 		kfree_data(userspace_coredump_name, userspace_coredump_name_len + 1);
2118 		userspace_coredump_name = NULL;
2119 	}
2120 
2121 	goto done;
2122 
2123 badtoolate:
2124 	/* Don't allow child process to execute any instructions */
2125 	if (!spawn) {
2126 		{
2127 			assert(exec_failure_reason != OS_REASON_NULL);
2128 			if (bootarg_execfailurereports) {
2129 				set_proc_name(imgp, current_proc());
2130 			}
2131 			psignal_with_reason(current_proc(), SIGKILL, exec_failure_reason);
2132 			exec_failure_reason = OS_REASON_NULL;
2133 
2134 			if (exec) {
2135 				/* Terminate the exec copy task */
2136 				task_terminate_internal(task);
2137 			}
2138 		}
2139 
2140 		/* We can't stop this system call at this point, so just pretend we succeeded */
2141 		error = 0;
2142 	} else {
2143 		os_reason_free(exec_failure_reason);
2144 		exec_failure_reason = OS_REASON_NULL;
2145 	}
2146 
2147 done:
2148 	if (load_result.threadstate) {
2149 		kfree_data(load_result.threadstate, load_result.threadstate_sz);
2150 		load_result.threadstate = NULL;
2151 	}
2152 
2153 bad:
2154 	/* If we hit this, we likely would have leaked an exit reason */
2155 	assert(exec_failure_reason == OS_REASON_NULL);
2156 	return error;
2157 }
2158 
2159 
2160 
2161 
2162 /*
2163  * Our image activator table; this is the table of the image types we are
2164  * capable of loading.  We list them in order of preference to ensure the
2165  * fastest image load speed.
2166  *
2167  * XXX hardcoded, for now; should use linker sets
2168  */
2169 struct execsw {
2170 	int(*const ex_imgact)(struct image_params *);
2171 	const char *ex_name;
2172 }const execsw[] = {
2173 	{ exec_mach_imgact, "Mach-o Binary" },
2174 	{ exec_fat_imgact, "Fat Binary" },
2175 	{ exec_shell_imgact, "Interpreter Script" },
2176 	{ NULL, NULL}
2177 };
2178 
2179 
2180 /*
2181  * exec_activate_image
2182  *
2183  * Description:	Iterate through the available image activators, and activate
2184  *		the image associated with the imgp structure.  We start with
2185  *		the activator for Mach-o binaries followed by that for Fat binaries
2186  *		for Interpreter scripts.
2187  *
2188  * Parameters:	struct image_params *	Image parameter block
2189  *
2190  * Returns:	0			Success
2191  *		ENOEXEC			No activator for image.
2192  *		EBADEXEC		The executable is corrupt/unknown
2193  *	execargs_alloc:EINVAL		Invalid argument
2194  *	execargs_alloc:EACCES		Permission denied
2195  *	execargs_alloc:EINTR		Interrupted function
2196  *	execargs_alloc:ENOMEM		Not enough space
2197  *	exec_save_path:EFAULT		Bad address
2198  *	exec_save_path:ENAMETOOLONG	Filename too long
2199  *	exec_check_permissions:EACCES	Permission denied
2200  *	exec_check_permissions:ENOEXEC	Executable file format error
2201  *	exec_check_permissions:ETXTBSY	Text file busy [misuse of error code]
2202  *	exec_check_permissions:???
2203  *	namei:???
2204  *	vn_rdwr:???			[anything vn_rdwr can return]
2205  *	<ex_imgact>:???			[anything an imgact can return]
2206  *	EDEADLK				Process is being terminated
2207  */
2208 static int
exec_activate_image(struct image_params * imgp)2209 exec_activate_image(struct image_params *imgp)
2210 {
2211 	struct nameidata *ndp = NULL;
2212 	const char *excpath;
2213 	int error;
2214 	int resid;
2215 	int once = 1;   /* save SGUID-ness for interpreted files */
2216 	int i;
2217 	int itercount = 0;
2218 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2219 
2220 	/*
2221 	 * For exec, the translock needs to be taken on old proc and not
2222 	 * on new shadow proc.
2223 	 */
2224 	if (imgp->ip_flags & IMGPF_EXEC) {
2225 		p = current_proc();
2226 	}
2227 
2228 	error = execargs_alloc(imgp);
2229 	if (error) {
2230 		goto bad_notrans;
2231 	}
2232 
2233 	error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
2234 	if (error) {
2235 		goto bad_notrans;
2236 	}
2237 
2238 	/* Use excpath, which contains the copyin-ed exec path */
2239 	DTRACE_PROC1(exec, uintptr_t, excpath);
2240 
2241 	ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2242 
2243 	NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
2244 	    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2245 
2246 again:
2247 	error = namei(ndp);
2248 	if (error) {
2249 		if (error == ERESTART) {
2250 			error = EINTR;
2251 		}
2252 		goto bad_notrans;
2253 	}
2254 	imgp->ip_ndp = ndp;     /* successful namei(); call nameidone() later */
2255 	imgp->ip_vp = ndp->ni_vp;       /* if set, need to vnode_put() at some point */
2256 
2257 	/*
2258 	 * Before we start the transition from binary A to binary B, make
2259 	 * sure another thread hasn't started exiting the process.  We grab
2260 	 * the proc lock to check p_lflag initially, and the transition
2261 	 * mechanism ensures that the value doesn't change after we release
2262 	 * the lock.
2263 	 */
2264 	proc_lock(p);
2265 	if (p->p_lflag & P_LEXIT) {
2266 		error = EDEADLK;
2267 		proc_unlock(p);
2268 		goto bad_notrans;
2269 	}
2270 	error = proc_transstart(p, 1, 0);
2271 	proc_unlock(p);
2272 	if (error) {
2273 		goto bad_notrans;
2274 	}
2275 
2276 	error = exec_check_permissions(imgp);
2277 	if (error) {
2278 		goto bad;
2279 	}
2280 
2281 	/* Copy; avoid invocation of an interpreter overwriting the original */
2282 	if (once) {
2283 		once = 0;
2284 		*imgp->ip_origvattr = *imgp->ip_vattr;
2285 	}
2286 
2287 	error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
2288 	    UIO_SYSSPACE, IO_NODELOCKED,
2289 	    vfs_context_ucred(imgp->ip_vfs_context),
2290 	    &resid, vfs_context_proc(imgp->ip_vfs_context));
2291 	if (error) {
2292 		goto bad;
2293 	}
2294 
2295 	if (resid) {
2296 		memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
2297 	}
2298 
2299 encapsulated_binary:
2300 	/* Limit the number of iterations we will attempt on each binary */
2301 	if (++itercount > EAI_ITERLIMIT) {
2302 		error = EBADEXEC;
2303 		goto bad;
2304 	}
2305 	error = -1;
2306 	for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
2307 		error = (*execsw[i].ex_imgact)(imgp);
2308 
2309 		switch (error) {
2310 		/* case -1: not claimed: continue */
2311 		case -2:                /* Encapsulated binary, imgp->ip_XXX set for next iteration */
2312 			goto encapsulated_binary;
2313 
2314 		case -3:                /* Interpreter */
2315 #if CONFIG_MACF
2316 			/*
2317 			 * Copy the script label for later use. Note that
2318 			 * the label can be different when the script is
2319 			 * actually read by the interpreter.
2320 			 */
2321 			if (imgp->ip_scriptlabelp) {
2322 				mac_vnode_label_free(imgp->ip_scriptlabelp);
2323 				imgp->ip_scriptlabelp = NULL;
2324 			}
2325 			imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
2326 			if (imgp->ip_scriptlabelp == NULL) {
2327 				error = ENOMEM;
2328 				break;
2329 			}
2330 			mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
2331 			    imgp->ip_scriptlabelp);
2332 
2333 			/*
2334 			 * Take a ref of the script vnode for later use.
2335 			 */
2336 			if (imgp->ip_scriptvp) {
2337 				vnode_put(imgp->ip_scriptvp);
2338 				imgp->ip_scriptvp = NULLVP;
2339 			}
2340 			if (vnode_getwithref(imgp->ip_vp) == 0) {
2341 				imgp->ip_scriptvp = imgp->ip_vp;
2342 			}
2343 #endif
2344 
2345 			nameidone(ndp);
2346 
2347 			vnode_put(imgp->ip_vp);
2348 			imgp->ip_vp = NULL;     /* already put */
2349 			imgp->ip_ndp = NULL; /* already nameidone */
2350 
2351 			/* Use excpath, which exec_shell_imgact reset to the interpreter */
2352 			NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
2353 			    UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2354 
2355 			proc_transend(p, 0);
2356 			goto again;
2357 
2358 		default:
2359 			break;
2360 		}
2361 	}
2362 
2363 	if (error == -1) {
2364 		error = ENOEXEC;
2365 	} else if (error == 0) {
2366 		if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
2367 			AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
2368 		}
2369 
2370 		/*
2371 		 * Call out to allow 3rd party notification of exec.
2372 		 * Ignore result of kauth_authorize_fileop call.
2373 		 */
2374 		if (kauth_authorize_fileop_has_listeners()) {
2375 			kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
2376 			    KAUTH_FILEOP_EXEC,
2377 			    (uintptr_t)ndp->ni_vp, 0);
2378 		}
2379 	}
2380 bad:
2381 	proc_transend(p, 0);
2382 
2383 bad_notrans:
2384 	if (imgp->ip_strings) {
2385 		execargs_free(imgp);
2386 	}
2387 	if (imgp->ip_ndp) {
2388 		nameidone(imgp->ip_ndp);
2389 	}
2390 	kfree_type(struct nameidata, ndp);
2391 
2392 	return error;
2393 }
2394 
2395 /*
2396  * exec_validate_spawnattr_policy
2397  *
2398  * Description: Validates the entitlements required to set the apptype.
2399  *
2400  * Parameters:  int psa_apptype         posix spawn attribute apptype
2401  *
2402  * Returns:     0                       Success
2403  *              EPERM                   Failure
2404  */
2405 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)2406 exec_validate_spawnattr_policy(int psa_apptype)
2407 {
2408 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2409 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2410 		if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
2411 			if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
2412 				return EPERM;
2413 			}
2414 		}
2415 	}
2416 
2417 	return 0;
2418 }
2419 
2420 /*
2421  * exec_handle_spawnattr_policy
2422  *
2423  * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
2424  *
2425  * Parameters:  proc_t p                process to apply attributes to
2426  *              int psa_apptype         posix spawn attribute apptype
2427  *
2428  * Returns:     0                       Success
2429  */
2430 static errno_t
exec_handle_spawnattr_policy(proc_t p,thread_t thread,int psa_apptype,uint64_t psa_qos_clamp,task_role_t psa_darwin_role,struct exec_port_actions * port_actions)2431 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2432     task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2433 {
2434 	int apptype     = TASK_APPTYPE_NONE;
2435 	int qos_clamp   = THREAD_QOS_UNSPECIFIED;
2436 	task_role_t role = TASK_UNSPECIFIED;
2437 
2438 	if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2439 		int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2440 
2441 		switch (proctype) {
2442 		case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2443 			apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2444 			break;
2445 		case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2446 			apptype = TASK_APPTYPE_DAEMON_STANDARD;
2447 			break;
2448 		case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2449 			apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2450 			break;
2451 		case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2452 			apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2453 			break;
2454 		case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2455 			apptype = TASK_APPTYPE_APP_DEFAULT;
2456 			break;
2457 		case POSIX_SPAWN_PROC_TYPE_DRIVER:
2458 			apptype = TASK_APPTYPE_DRIVER;
2459 			break;
2460 		default:
2461 			apptype = TASK_APPTYPE_NONE;
2462 			/* TODO: Should an invalid value here fail the spawn? */
2463 			break;
2464 		}
2465 	}
2466 
2467 	if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2468 		switch (psa_qos_clamp) {
2469 		case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2470 			qos_clamp = THREAD_QOS_UTILITY;
2471 			break;
2472 		case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2473 			qos_clamp = THREAD_QOS_BACKGROUND;
2474 			break;
2475 		case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2476 			qos_clamp = THREAD_QOS_MAINTENANCE;
2477 			break;
2478 		default:
2479 			qos_clamp = THREAD_QOS_UNSPECIFIED;
2480 			/* TODO: Should an invalid value here fail the spawn? */
2481 			break;
2482 		}
2483 	}
2484 
2485 	if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2486 		proc_darwin_role_to_task_role(psa_darwin_role, &role);
2487 	}
2488 
2489 	if (apptype != TASK_APPTYPE_NONE ||
2490 	    qos_clamp != THREAD_QOS_UNSPECIFIED ||
2491 	    role != TASK_UNSPECIFIED ||
2492 	    port_actions->portwatch_count) {
2493 		proc_set_task_spawnpolicy(proc_task(p), thread, apptype, qos_clamp, role,
2494 		    port_actions->portwatch_array, port_actions->portwatch_count);
2495 	}
2496 
2497 	if (port_actions->registered_count) {
2498 		if (mach_ports_register(proc_task(p), port_actions->registered_array,
2499 		    port_actions->registered_count)) {
2500 			return EINVAL;
2501 		}
2502 		/* mach_ports_register() consumed the array */
2503 		port_actions->registered_array = NULL;
2504 		port_actions->registered_count = 0;
2505 	}
2506 
2507 	return 0;
2508 }
2509 
2510 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2511 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2512 {
2513 	if (port_actions->excport_array) {
2514 		for (uint32_t i = 0; i < port_actions->exception_port_count; i++) {
2515 			ipc_port_t port = NULL;
2516 			if ((port = port_actions->excport_array[i].port) != NULL) {
2517 				ipc_port_release_send(port);
2518 			}
2519 		}
2520 		kfree_type(struct exception_port_action_t, port_actions->exception_port_count,
2521 		    port_actions->excport_array);
2522 	}
2523 
2524 	if (port_actions->portwatch_array) {
2525 		for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2526 			ipc_port_t port = NULL;
2527 			if ((port = port_actions->portwatch_array[i]) != NULL) {
2528 				ipc_port_release_send(port);
2529 			}
2530 		}
2531 		kfree_type(ipc_port_t, port_actions->portwatch_count,
2532 		    port_actions->portwatch_array);
2533 	}
2534 
2535 	if (port_actions->registered_array) {
2536 		for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2537 			ipc_port_t port = NULL;
2538 			if ((port = port_actions->registered_array[i]) != NULL) {
2539 				ipc_port_release_send(port);
2540 			}
2541 		}
2542 		kfree_type(ipc_port_t, port_actions->registered_count,
2543 		    port_actions->registered_array);
2544 	}
2545 }
2546 
2547 /*
2548  * exec_handle_port_actions
2549  *
2550  * Description:	Go through the _posix_port_actions_t contents,
2551  *              calling task_set_special_port, task_set_exception_ports
2552  *              and/or audit_session_spawnjoin for the current task.
2553  *
2554  * Parameters:	struct image_params *	Image parameter block
2555  *
2556  * Returns:	0			Success
2557  *              EINVAL			Failure
2558  *              ENOTSUP			Illegal posix_spawn attr flag was set
2559  */
2560 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2561 exec_handle_port_actions(struct image_params *imgp,
2562     struct exec_port_actions *actions)
2563 {
2564 	_posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2565 #if CONFIG_AUDIT
2566 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2567 #endif
2568 	_ps_port_action_t *act = NULL;
2569 	task_t task = get_threadtask(imgp->ip_new_thread);
2570 	ipc_port_t port = NULL;
2571 	errno_t ret = 0;
2572 	int i = 0, portwatch_i = 0, registered_i = 0, excport_i = 0;
2573 	kern_return_t kr;
2574 	boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2575 	boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2576 	int ptrauth_task_port_count = 0;
2577 
2578 	for (i = 0; i < pacts->pspa_count; i++) {
2579 		act = &pacts->pspa_actions[i];
2580 
2581 		switch (act->port_type) {
2582 		case PSPA_SPECIAL:
2583 #if CONFIG_AUDIT
2584 		case PSPA_AU_SESSION:
2585 #endif
2586 			break;
2587 		case PSPA_EXCEPTION:
2588 			if (++actions->exception_port_count > TASK_MAX_EXCEPTION_PORT_COUNT) {
2589 				ret = EINVAL;
2590 				goto done;
2591 			}
2592 			break;
2593 		case PSPA_IMP_WATCHPORTS:
2594 			if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
2595 				ret = EINVAL;
2596 				goto done;
2597 			}
2598 			break;
2599 		case PSPA_REGISTERED_PORTS:
2600 			if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
2601 				ret = EINVAL;
2602 				goto done;
2603 			}
2604 			break;
2605 		case PSPA_PTRAUTH_TASK_PORT:
2606 			if (++ptrauth_task_port_count > 1) {
2607 				ret = EINVAL;
2608 				goto done;
2609 			}
2610 			break;
2611 		default:
2612 			ret = EINVAL;
2613 			goto done;
2614 		}
2615 	}
2616 
2617 	if (actions->exception_port_count) {
2618 		actions->excport_array = kalloc_type(struct exception_port_action_t,
2619 		    actions->exception_port_count, Z_WAITOK | Z_ZERO);
2620 
2621 		if (actions->excport_array == NULL) {
2622 			ret = ENOMEM;
2623 			goto done;
2624 		}
2625 	}
2626 	if (actions->portwatch_count) {
2627 		if (in_exec && task_has_watchport_boost) {
2628 			ret = EINVAL;
2629 			goto done;
2630 		}
2631 		actions->portwatch_array = kalloc_type(ipc_port_t,
2632 		    actions->portwatch_count, Z_WAITOK | Z_ZERO);
2633 		if (actions->portwatch_array == NULL) {
2634 			ret = ENOMEM;
2635 			goto done;
2636 		}
2637 	}
2638 
2639 	if (actions->registered_count) {
2640 		actions->registered_array = kalloc_type(ipc_port_t,
2641 		    actions->registered_count, Z_WAITOK | Z_ZERO);
2642 		if (actions->registered_array == NULL) {
2643 			ret = ENOMEM;
2644 			goto done;
2645 		}
2646 	}
2647 
2648 	for (i = 0; i < pacts->pspa_count; i++) {
2649 		act = &pacts->pspa_actions[i];
2650 
2651 		if (MACH_PORT_VALID(act->new_port)) {
2652 			kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2653 			    act->new_port, MACH_MSG_TYPE_COPY_SEND,
2654 			    (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2655 
2656 			if (kr != KERN_SUCCESS) {
2657 				ret = EINVAL;
2658 				goto done;
2659 			}
2660 		} else {
2661 			/* it's NULL or DEAD */
2662 			port = CAST_MACH_NAME_TO_PORT(act->new_port);
2663 		}
2664 
2665 		switch (act->port_type) {
2666 		case PSPA_SPECIAL:
2667 			kr = task_set_special_port(task, act->which, port);
2668 
2669 			if (kr != KERN_SUCCESS) {
2670 				ret = EINVAL;
2671 			}
2672 			break;
2673 
2674 #if CONFIG_AUDIT
2675 		case PSPA_AU_SESSION:
2676 			ret = audit_session_spawnjoin(p, port);
2677 			if (ret) {
2678 				/* audit_session_spawnjoin() has already dropped the reference in case of error. */
2679 				goto done;
2680 			}
2681 
2682 			break;
2683 #endif
2684 		case PSPA_EXCEPTION:
2685 			assert(excport_i < actions->exception_port_count);
2686 			/* hold on to this till end of spawn */
2687 			actions->excport_array[excport_i].port_action = act;
2688 			actions->excport_array[excport_i].port = port;
2689 			excport_i++;
2690 			break;
2691 		case PSPA_IMP_WATCHPORTS:
2692 			assert(portwatch_i < actions->portwatch_count);
2693 			/* hold on to this till end of spawn */
2694 			actions->portwatch_array[portwatch_i++] = port;
2695 			break;
2696 		case PSPA_REGISTERED_PORTS:
2697 			assert(registered_i < actions->registered_count);
2698 			/* hold on to this till end of spawn */
2699 			actions->registered_array[registered_i++] = port;
2700 			break;
2701 
2702 		case PSPA_PTRAUTH_TASK_PORT:
2703 #if (DEVELOPMENT || DEBUG)
2704 #if defined(HAS_APPLE_PAC)
2705 			{
2706 				task_t ptr_auth_task = convert_port_to_task(port);
2707 
2708 				if (ptr_auth_task == TASK_NULL) {
2709 					ret = EINVAL;
2710 					break;
2711 				}
2712 
2713 				imgp->ip_inherited_shared_region_id =
2714 				    task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
2715 				    &imgp->ip_inherited_jop_pid);
2716 
2717 				/* Deallocate task ref returned by convert_port_to_task */
2718 				task_deallocate(ptr_auth_task);
2719 			}
2720 #endif /* HAS_APPLE_PAC */
2721 #endif /* (DEVELOPMENT || DEBUG) */
2722 
2723 			/* consume the port right in case of success */
2724 			ipc_port_release_send(port);
2725 			break;
2726 		default:
2727 			ret = EINVAL;
2728 			break;
2729 		}
2730 
2731 		if (ret) {
2732 			/* action failed, so release port resources */
2733 			ipc_port_release_send(port);
2734 			break;
2735 		}
2736 	}
2737 
2738 done:
2739 	if (0 != ret) {
2740 		DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2741 	}
2742 	return ret;
2743 }
2744 
2745 
2746 /*
2747  * exec_handle_exception_port_actions
2748  *
2749  * Description:	Go through the saved exception ports in exec_port_actions,
2750  *              calling task_set_exception_ports for the current Task.
2751  *              This must happen after image activation, and after exec_resettextvp()
2752  *				because task_set_exception_ports checks the `TF_PLATFORM` bit and entitlements.
2753  *
2754  * Parameters:	struct image_params *		Image parameter block
2755  *                              struct exec_port_actions *  Saved Port Actions
2756  *
2757  * Returns:	0			Success
2758  *              EINVAL			task_set_exception_ports failed
2759  */
2760 static errno_t
exec_handle_exception_port_actions(const struct image_params * imgp,const struct exec_port_actions * actions)2761 exec_handle_exception_port_actions(const struct image_params *imgp,
2762     const struct exec_port_actions *actions)
2763 {
2764 	task_t task = get_threadtask(imgp->ip_new_thread);
2765 
2766 	for (int i = 0; i < actions->exception_port_count; i++) {
2767 		ipc_port_t port = actions->excport_array[i].port;
2768 		_ps_port_action_t *act = actions->excport_array[i].port_action;
2769 		assert(act != NULL);
2770 		kern_return_t kr = task_set_exception_ports(task, act->mask, port,
2771 		    act->behavior, act->flavor);
2772 		if (kr != KERN_SUCCESS) {
2773 			DTRACE_PROC1(spawn__exception__port__failure, mach_port_name_t, act->new_port);
2774 			return EINVAL;
2775 		}
2776 		actions->excport_array[i].port = NULL;
2777 	}
2778 
2779 	return 0;
2780 }
2781 
2782 
2783 /*
2784  * exec_handle_file_actions
2785  *
2786  * Description:	Go through the _posix_file_actions_t contents applying the
2787  *		open, close, and dup2 operations to the open file table for
2788  *		the current process.
2789  *
2790  * Parameters:	struct image_params *	Image parameter block
2791  *
2792  * Returns:	0			Success
2793  *		???
2794  *
2795  * Note:	Actions are applied in the order specified, with the credential
2796  *		of the parent process.  This is done to permit the parent
2797  *		process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
2798  *		the child following operations the child may in fact not be
2799  *		normally permitted to perform.
2800  */
2801 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)2802 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
2803 {
2804 	int error = 0;
2805 	int action;
2806 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2807 	kauth_cred_t p_cred = vfs_context_ucred(imgp->ip_vfs_context);
2808 	_posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
2809 	int ival[2];            /* dummy retval for system calls) */
2810 #if CONFIG_AUDIT
2811 	struct uthread *uthread = current_uthread();
2812 #endif
2813 
2814 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
2815 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2816 
2817 		switch (psfa->psfaa_type) {
2818 		case PSFA_OPEN: {
2819 			/*
2820 			 * Open is different, in that it requires the use of
2821 			 * a path argument, which is normally copied in from
2822 			 * user space; because of this, we have to support an
2823 			 * open from kernel space that passes an address space
2824 			 * context of UIO_SYSSPACE, and casts the address
2825 			 * argument to a user_addr_t.
2826 			 */
2827 			struct vnode_attr *vap;
2828 			struct nameidata *ndp;
2829 			int mode = psfa->psfaa_openargs.psfao_mode;
2830 			int origfd;
2831 			struct {
2832 				struct vnode_attr va;
2833 				struct nameidata nd;
2834 			} *__open_data;
2835 
2836 			__open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
2837 			if (__open_data == NULL) {
2838 				error = ENOMEM;
2839 				break;
2840 			}
2841 
2842 			vap = &__open_data->va;
2843 			ndp = &__open_data->nd;
2844 
2845 			VATTR_INIT(vap);
2846 			/* Mask off all but regular access permissions */
2847 			mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
2848 			VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
2849 
2850 			AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
2851 
2852 			NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2853 			    CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
2854 			    imgp->ip_vfs_context);
2855 
2856 			error = open1(imgp->ip_vfs_context, ndp,
2857 			    psfa->psfaa_openargs.psfao_oflag,
2858 			    vap, NULL, NULL, &origfd, AUTH_OPEN_NOAUTHFD);
2859 
2860 			kfree_type(typeof(*__open_data), __open_data);
2861 
2862 			AUDIT_SUBCALL_EXIT(uthread, error);
2863 
2864 			/*
2865 			 * If there's an error, or we get the right fd by
2866 			 * accident, then drop out here.  This is easier than
2867 			 * reworking all the open code to preallocate fd
2868 			 * slots, and internally taking one as an argument.
2869 			 */
2870 			if (error || origfd == psfa->psfaa_filedes) {
2871 				break;
2872 			}
2873 
2874 			/*
2875 			 * If we didn't fall out from an error, we ended up
2876 			 * with the wrong fd; so now we've got to try to dup2
2877 			 * it to the right one.
2878 			 */
2879 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2880 			error = dup2(p, p_cred, origfd, psfa->psfaa_filedes, ival);
2881 			AUDIT_SUBCALL_EXIT(uthread, error);
2882 			if (error) {
2883 				break;
2884 			}
2885 
2886 			/*
2887 			 * Finally, close the original fd.
2888 			 */
2889 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2890 			error = close_nocancel(p, p_cred, origfd);
2891 			AUDIT_SUBCALL_EXIT(uthread, error);
2892 		}
2893 		break;
2894 
2895 		case PSFA_DUP2: {
2896 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2897 			error = dup2(p, p_cred, psfa->psfaa_filedes,
2898 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2899 			AUDIT_SUBCALL_EXIT(uthread, error);
2900 		}
2901 		break;
2902 
2903 		case PSFA_FILEPORT_DUP2: {
2904 			ipc_port_t port;
2905 			kern_return_t kr;
2906 			int origfd;
2907 
2908 			if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
2909 				error = EINVAL;
2910 				break;
2911 			}
2912 
2913 			kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2914 			    psfa->psfaa_fileport, MACH_MSG_TYPE_COPY_SEND,
2915 			    (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2916 
2917 			if (kr != KERN_SUCCESS) {
2918 				error = EINVAL;
2919 				break;
2920 			}
2921 
2922 			error = fileport_makefd(p, port, 0, &origfd);
2923 
2924 			if (IPC_PORT_NULL != port) {
2925 				ipc_port_release_send(port);
2926 			}
2927 
2928 			if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
2929 				break;
2930 			}
2931 
2932 			AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2933 			error = dup2(p, p_cred, origfd,
2934 			    psfa->psfaa_dup2args.psfad_newfiledes, ival);
2935 			AUDIT_SUBCALL_EXIT(uthread, error);
2936 			if (error) {
2937 				break;
2938 			}
2939 
2940 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2941 			error = close_nocancel(p, p_cred, origfd);
2942 			AUDIT_SUBCALL_EXIT(uthread, error);
2943 		}
2944 		break;
2945 
2946 		case PSFA_CLOSE: {
2947 			AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2948 			error = close_nocancel(p, p_cred, psfa->psfaa_filedes);
2949 			AUDIT_SUBCALL_EXIT(uthread, error);
2950 		}
2951 		break;
2952 
2953 		case PSFA_INHERIT: {
2954 			struct fileproc *fp;
2955 
2956 			/*
2957 			 * Check to see if the descriptor exists, and
2958 			 * ensure it's -not- marked as close-on-exec.
2959 			 *
2960 			 * Attempting to "inherit" a guarded fd will
2961 			 * result in a error.
2962 			 */
2963 
2964 			proc_fdlock(p);
2965 			if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
2966 				error = EBADF;
2967 			} else if (fp->fp_guard_attrs) {
2968 				error = fp_guard_exception(p, psfa->psfaa_filedes,
2969 				    fp, kGUARD_EXC_NOCLOEXEC);
2970 			} else {
2971 				fp->fp_flags &= ~FP_CLOEXEC;
2972 				error = 0;
2973 			}
2974 			proc_fdunlock(p);
2975 		}
2976 		break;
2977 
2978 		case PSFA_CHDIR: {
2979 			/*
2980 			 * Chdir is different, in that it requires the use of
2981 			 * a path argument, which is normally copied in from
2982 			 * user space; because of this, we have to support a
2983 			 * chdir from kernel space that passes an address space
2984 			 * context of UIO_SYSSPACE, and casts the address
2985 			 * argument to a user_addr_t.
2986 			 */
2987 			struct nameidata *nd;
2988 			nd = kalloc_type(struct nameidata,
2989 			    Z_WAITOK | Z_ZERO | Z_NOFAIL);
2990 
2991 			AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
2992 			NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2993 			    CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
2994 			    imgp->ip_vfs_context);
2995 
2996 			error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
2997 			kfree_type(struct nameidata, nd);
2998 			AUDIT_SUBCALL_EXIT(uthread, error);
2999 		}
3000 		break;
3001 
3002 		case PSFA_FCHDIR: {
3003 			AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
3004 			error = fchdir(p, imgp->ip_vfs_context,
3005 			    psfa->psfaa_filedes, false);
3006 			AUDIT_SUBCALL_EXIT(uthread, error);
3007 		}
3008 		break;
3009 
3010 		default:
3011 			error = EINVAL;
3012 			break;
3013 		}
3014 
3015 		/* All file actions failures are considered fatal, per POSIX */
3016 
3017 		if (error) {
3018 			if (PSFA_OPEN == psfa->psfaa_type) {
3019 				DTRACE_PROC1(spawn__open__failure, uintptr_t,
3020 				    psfa->psfaa_openargs.psfao_path);
3021 			} else {
3022 				DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
3023 			}
3024 			break;
3025 		}
3026 	}
3027 
3028 	if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
3029 		return error;
3030 	}
3031 
3032 	/*
3033 	 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
3034 	 * this spawn only) as if "close on exec" is the default
3035 	 * disposition of all pre-existing file descriptors.  In this case,
3036 	 * the list of file descriptors mentioned in the file actions
3037 	 * are the only ones that can be inherited, so mark them now.
3038 	 *
3039 	 * The actual closing part comes later, in fdt_exec().
3040 	 */
3041 	proc_fdlock(p);
3042 	for (action = 0; action < px_sfap->psfa_act_count; action++) {
3043 		_psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3044 		int fd = psfa->psfaa_filedes;
3045 
3046 		switch (psfa->psfaa_type) {
3047 		case PSFA_DUP2:
3048 		case PSFA_FILEPORT_DUP2:
3049 			fd = psfa->psfaa_dup2args.psfad_newfiledes;
3050 			OS_FALLTHROUGH;
3051 		case PSFA_OPEN:
3052 		case PSFA_INHERIT:
3053 			*fdflags(p, fd) |= UF_INHERIT;
3054 			break;
3055 
3056 		case PSFA_CLOSE:
3057 		case PSFA_CHDIR:
3058 		case PSFA_FCHDIR:
3059 			/*
3060 			 * Although PSFA_FCHDIR does have a file descriptor, it is not
3061 			 * *creating* one, thus we do not automatically mark it for
3062 			 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
3063 			 * wishes it to be inherited should use the PSFA_INHERIT action
3064 			 * explicitly.
3065 			 */
3066 			break;
3067 		}
3068 	}
3069 	proc_fdunlock(p);
3070 
3071 	return 0;
3072 }
3073 
3074 #if CONFIG_MACF
3075 /*
3076  * Check that the extension's data is within the bounds of the
3077  * allocation storing all extensions' data
3078  */
3079 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)3080 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
3081     const _ps_mac_policy_extension_t *ext)
3082 {
3083 	uint64_t dataend;
3084 
3085 	if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
3086 		return EOVERFLOW;
3087 	}
3088 	if (__improbable(dataend > px_s->datalen)) {
3089 		return EINVAL;
3090 	}
3091 
3092 	return 0;
3093 }
3094 
3095 /*
3096  * exec_spawnattr_getmacpolicyinfo
3097  */
3098 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)3099 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
3100 {
3101 	const struct ip_px_smpx_s *px_s = macextensions;
3102 	const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
3103 	int i;
3104 
3105 	if (px_s == NULL) {
3106 		return NULL;
3107 	}
3108 
3109 	psmx = px_s->array;
3110 	if (psmx == NULL) {
3111 		return NULL;
3112 	}
3113 
3114 	for (i = 0; i < psmx->psmx_count; i++) {
3115 		const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3116 		if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
3117 			if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
3118 				panic("invalid mac policy extension data");
3119 			}
3120 			if (lenp != NULL) {
3121 				*lenp = (size_t)extension->datalen;
3122 			}
3123 			return (void *)((uintptr_t)px_s->data + extension->dataoff);
3124 		}
3125 	}
3126 
3127 	if (lenp != NULL) {
3128 		*lenp = 0;
3129 	}
3130 	return NULL;
3131 }
3132 
3133 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)3134 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
3135     struct ip_px_smpx_s *pxsp)
3136 {
3137 	_posix_spawn_mac_policy_extensions_t psmx = NULL;
3138 	uint8_t *data = NULL;
3139 	uint64_t datalen = 0;
3140 	uint64_t dataoff = 0;
3141 	int error = 0;
3142 
3143 	bzero(pxsp, sizeof(*pxsp));
3144 
3145 	if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
3146 	    px_args->mac_extensions_size > PAGE_SIZE) {
3147 		error = EINVAL;
3148 		goto bad;
3149 	}
3150 
3151 	psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
3152 	if (psmx == NULL) {
3153 		error = ENOMEM;
3154 		goto bad;
3155 	}
3156 
3157 	error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
3158 	if (error) {
3159 		goto bad;
3160 	}
3161 
3162 	size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
3163 	if (extsize == 0 || extsize > px_args->mac_extensions_size) {
3164 		error = EINVAL;
3165 		goto bad;
3166 	}
3167 
3168 	for (int i = 0; i < psmx->psmx_count; i++) {
3169 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3170 		if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
3171 			error = EINVAL;
3172 			goto bad;
3173 		}
3174 		if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
3175 			error = ENOMEM;
3176 			goto bad;
3177 		}
3178 	}
3179 
3180 	data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
3181 	if (data == NULL) {
3182 		error = ENOMEM;
3183 		goto bad;
3184 	}
3185 
3186 	for (int i = 0; i < psmx->psmx_count; i++) {
3187 		_ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3188 
3189 #if !__LP64__
3190 		if (extension->data > UINT32_MAX) {
3191 			goto bad;
3192 		}
3193 #endif
3194 		error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
3195 		if (error) {
3196 			error = ENOMEM;
3197 			goto bad;
3198 		}
3199 		extension->dataoff = dataoff;
3200 		dataoff += extension->datalen;
3201 	}
3202 
3203 	pxsp->array = psmx;
3204 	pxsp->data = data;
3205 	pxsp->datalen = datalen;
3206 	return 0;
3207 
3208 bad:
3209 	kfree_data(psmx, px_args->mac_extensions_size);
3210 	kfree_data(data, (vm_size_t)datalen);
3211 	return error;
3212 }
3213 #endif /* CONFIG_MACF */
3214 
3215 #if CONFIG_COALITIONS
3216 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])3217 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
3218 {
3219 	for (int c = 0; c < COALITION_NUM_TYPES; c++) {
3220 		if (coal[c]) {
3221 			coalition_remove_active(coal[c]);
3222 			coalition_release(coal[c]);
3223 		}
3224 	}
3225 }
3226 #endif
3227 
3228 #if CONFIG_PERSONAS
3229 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)3230 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
3231 {
3232 	int error = 0;
3233 	struct persona *persona = NULL;
3234 
3235 	if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
3236 		return EPERM;
3237 	}
3238 
3239 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3240 		if (px_persona->pspi_ngroups > NGROUPS_MAX) {
3241 			return EINVAL;
3242 		}
3243 	}
3244 
3245 	persona = persona_lookup(px_persona->pspi_id);
3246 	if (!persona) {
3247 		error = ESRCH;
3248 		goto out;
3249 	}
3250 
3251 out:
3252 	if (persona) {
3253 		persona_put(persona);
3254 	}
3255 
3256 	return error;
3257 }
3258 
3259 static bool
kauth_cred_model_setpersona(kauth_cred_t model,struct _posix_spawn_persona_info * px_persona)3260 kauth_cred_model_setpersona(
3261 	kauth_cred_t            model,
3262 	struct _posix_spawn_persona_info *px_persona)
3263 {
3264 	bool updated = false;
3265 
3266 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
3267 		updated |= kauth_cred_model_setresuid(model,
3268 		    px_persona->pspi_uid,
3269 		    px_persona->pspi_uid,
3270 		    px_persona->pspi_uid,
3271 		    KAUTH_UID_NONE);
3272 	}
3273 
3274 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
3275 		updated |= kauth_cred_model_setresgid(model,
3276 		    px_persona->pspi_gid,
3277 		    px_persona->pspi_gid,
3278 		    px_persona->pspi_gid);
3279 	}
3280 
3281 	if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3282 		updated |= kauth_cred_model_setgroups(model,
3283 		    px_persona->pspi_groups,
3284 		    px_persona->pspi_ngroups,
3285 		    px_persona->pspi_gmuid);
3286 	}
3287 
3288 	return updated;
3289 }
3290 
3291 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)3292 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
3293 {
3294 	struct persona *persona = NULL;
3295 
3296 	/*
3297 	 * we want to spawn into the given persona, but we want to override
3298 	 * the kauth with a different UID/GID combo
3299 	 */
3300 	persona = persona_lookup(px_persona->pspi_id);
3301 	if (!persona) {
3302 		return ESRCH;
3303 	}
3304 
3305 	return persona_proc_adopt(p, persona,
3306 	           ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
3307 		return kauth_cred_model_setpersona(model, px_persona);
3308 	});
3309 }
3310 #endif
3311 
3312 #if __arm64__
3313 #if DEVELOPMENT || DEBUG
3314 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
3315     LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
3316 
3317 __startup_func
3318 static void
legacy_footprint_entitlement_mode_init(void)3319 legacy_footprint_entitlement_mode_init(void)
3320 {
3321 	/*
3322 	 * legacy_footprint_entitlement_mode specifies the behavior we want associated
3323 	 * with the entitlement. The supported modes are:
3324 	 *
3325 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3326 	 *	Indicates that we want every process to have the memory accounting
3327 	 *	that is available in iOS 12.0 and beyond.
3328 	 *
3329 	 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3330 	 *	Indicates that for every process that has the 'legacy footprint entitlement',
3331 	 *      we want to give it the old iOS 11.0 accounting behavior which accounted some
3332 	 *	of the process's memory to the kernel.
3333 	 *
3334 	 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3335 	 *      Indicates that for every process that has the 'legacy footprint entitlement',
3336 	 *	we want it to have a higher memory limit which will help them acclimate to the
3337 	 *	iOS 12.0 (& beyond) accounting behavior that does the right accounting.
3338 	 *      The bonus added to the system-wide task limit to calculate this higher memory limit
3339 	 *      is available in legacy_footprint_bonus_mb.
3340 	 */
3341 
3342 	if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
3343 	    legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
3344 		legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
3345 	}
3346 }
3347 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
3348 #else
3349 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
3350 #endif
3351 
3352 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)3353 proc_legacy_footprint_entitled(proc_t p, task_t task)
3354 {
3355 #pragma unused(p)
3356 	boolean_t legacy_footprint_entitled;
3357 
3358 	switch (legacy_footprint_entitlement_mode) {
3359 	case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3360 		/* the entitlement is ignored */
3361 		break;
3362 	case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3363 		/* the entitlement grants iOS11 legacy accounting */
3364 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3365 		if (legacy_footprint_entitled) {
3366 			task_set_legacy_footprint(task);
3367 		}
3368 		break;
3369 	case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3370 		/* the entitlement grants a footprint limit increase */
3371 		legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3372 		if (legacy_footprint_entitled) {
3373 			task_set_extra_footprint_limit(task);
3374 		}
3375 		break;
3376 	default:
3377 		break;
3378 	}
3379 }
3380 
3381 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)3382 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
3383 {
3384 #pragma unused(p)
3385 	boolean_t ios13extended_footprint_entitled;
3386 
3387 	/* the entitlement grants a footprint limit increase */
3388 	ios13extended_footprint_entitled = memorystatus_task_has_ios13extended_footprint_limit(proc_task(p));
3389 	if (ios13extended_footprint_entitled) {
3390 		task_set_ios13extended_footprint_limit(task);
3391 	}
3392 }
3393 
3394 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)3395 proc_increased_memory_limit_entitled(proc_t p, task_t task)
3396 {
3397 	bool entitled = memorystatus_task_has_increased_memory_limit_entitlement(task);
3398 
3399 	if (entitled) {
3400 		memorystatus_act_on_entitled_task_limit(p);
3401 	}
3402 }
3403 
3404 /*
3405  * Check for any of the various entitlements that permit a higher
3406  * task footprint limit or alternate accounting and apply them.
3407  */
3408 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)3409 proc_footprint_entitlement_hacks(proc_t p, task_t task)
3410 {
3411 	proc_legacy_footprint_entitled(p, task);
3412 	proc_ios13extended_footprint_entitled(p, task);
3413 	proc_increased_memory_limit_entitled(p, task);
3414 }
3415 #endif /* __arm64__ */
3416 
3417 /*
3418  * Processes with certain entitlements are granted a jumbo-size VM map.
3419  */
3420 static inline void
proc_apply_jit_and_vm_policies(struct image_params * imgp,proc_t p,task_t task)3421 proc_apply_jit_and_vm_policies(struct image_params *imgp, proc_t p, task_t task)
3422 {
3423 #if CONFIG_MACF
3424 	bool jit_entitled = false;
3425 #endif /* CONFIG_MACF */
3426 	bool needs_jumbo_va = false;
3427 	struct _posix_spawnattr *psa = imgp->ip_px_sa;
3428 
3429 #if CONFIG_MACF
3430 	jit_entitled = (mac_proc_check_map_anon(p, proc_ucred_unsafe(p),
3431 	    0, 0, 0, MAP_JIT, NULL) == 0);
3432 	needs_jumbo_va = jit_entitled || IOTaskHasEntitlement(task,
3433 	    "com.apple.developer.kernel.extended-virtual-addressing") ||
3434 	    memorystatus_task_has_increased_memory_limit_entitlement(task);
3435 #else
3436 #pragma unused(p)
3437 #endif /* CONFIG_MACF */
3438 
3439 
3440 	if (needs_jumbo_va) {
3441 		vm_map_set_jumbo(get_task_map(task));
3442 	}
3443 
3444 	if (psa && psa->psa_max_addr) {
3445 		vm_map_set_max_addr(get_task_map(task), psa->psa_max_addr);
3446 	}
3447 
3448 #if CONFIG_MAP_RANGES
3449 	if (task_is_hardened_binary(task) && !proc_is_simulated(p)) {
3450 		/*
3451 		 * This must be done last as it needs to observe
3452 		 * any kind of VA space growth that was requested.
3453 		 * This is used by the secure allocator, so
3454 		 * must be applied to all hardened binaries
3455 		 */
3456 		vm_map_range_configure(get_task_map(task));
3457 	}
3458 #endif /* CONFIG_MAP_RANGES */
3459 
3460 #if CONFIG_MACF
3461 	if (jit_entitled) {
3462 		vm_map_set_jit_entitled(get_task_map(task));
3463 
3464 	}
3465 #endif /* CONFIG_MACF */
3466 
3467 #if XNU_TARGET_OS_OSX
3468 	/* TPRO cannot be enforced on binaries that load 3P plugins on macos - rdar://107420220 */
3469 	const bool task_loads_3P_plugins = imgp->ip_flags & IMGPF_3P_PLUGINS;
3470 #endif /* XNU_TARGET_OS_OSX */
3471 
3472 	if (task_is_hardened_binary(task)
3473 #if XNU_TARGET_OS_OSX
3474 	    && !task_loads_3P_plugins
3475 #endif /* XNU_TARGET_OS_OSX */
3476 	    ) {
3477 		/*
3478 		 * Pre-emptively disable TPRO remapping for
3479 		 * hardened binaries (which do not load 3P plugins)
3480 		 */
3481 		vm_map_set_tpro_enforcement(get_task_map(task));
3482 	}
3483 }
3484 
3485 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)3486 spawn_posix_cred_adopt(proc_t p,
3487     struct _posix_spawn_posix_cred_info *px_pcred_info)
3488 {
3489 	int error = 0;
3490 
3491 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3492 		struct setgid_args args = {
3493 			.gid = px_pcred_info->pspci_gid,
3494 		};
3495 		error = setgid(p, &args, NULL);
3496 		if (error) {
3497 			return error;
3498 		}
3499 	}
3500 
3501 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3502 		error = setgroups_internal(p,
3503 		    px_pcred_info->pspci_ngroups,
3504 		    px_pcred_info->pspci_groups,
3505 		    px_pcred_info->pspci_gmuid);
3506 		if (error) {
3507 			return error;
3508 		}
3509 	}
3510 
3511 	if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3512 		struct setuid_args args = {
3513 			.uid = px_pcred_info->pspci_uid,
3514 		};
3515 		error = setuid(p, &args, NULL);
3516 		if (error) {
3517 			return error;
3518 		}
3519 	}
3520 	return 0;
3521 }
3522 
3523 /*
3524  * posix_spawn
3525  *
3526  * Parameters:	uap->pid		Pointer to pid return area
3527  *		uap->fname		File name to exec
3528  *		uap->argp		Argument list
3529  *		uap->envp		Environment list
3530  *
3531  * Returns:	0			Success
3532  *		EINVAL			Invalid argument
3533  *		ENOTSUP			Not supported
3534  *		ENOEXEC			Executable file format error
3535  *	exec_activate_image:EINVAL	Invalid argument
3536  *	exec_activate_image:EACCES	Permission denied
3537  *	exec_activate_image:EINTR	Interrupted function
3538  *	exec_activate_image:ENOMEM	Not enough space
3539  *	exec_activate_image:EFAULT	Bad address
3540  *	exec_activate_image:ENAMETOOLONG	Filename too long
3541  *	exec_activate_image:ENOEXEC	Executable file format error
3542  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
3543  *	exec_activate_image:EAUTH	Image decryption failed
3544  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
3545  *	exec_activate_image:???
3546  *	mac_execve_enter:???
3547  *
3548  * TODO:	Expect to need __mac_posix_spawn() at some point...
3549  *		Handle posix_spawnattr_t
3550  *		Handle posix_spawn_file_actions_t
3551  */
3552 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3553 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3554 {
3555 	proc_t p = ap;
3556 	user_addr_t pid = uap->pid;
3557 	int ival[2];            /* dummy retval for setpgid() */
3558 	char *subsystem_root_path = NULL;
3559 	struct image_params *imgp = NULL;
3560 	struct vnode_attr *vap = NULL;
3561 	struct vnode_attr *origvap = NULL;
3562 	struct uthread  *uthread = 0;   /* compiler complains if not set to 0*/
3563 	int error, sig;
3564 	int is_64 = IS_64BIT_PROCESS(p);
3565 	struct vfs_context context;
3566 	struct user__posix_spawn_args_desc px_args = {};
3567 	struct _posix_spawnattr px_sa = {};
3568 	_posix_spawn_file_actions_t px_sfap = NULL;
3569 	_posix_spawn_port_actions_t px_spap = NULL;
3570 	struct __kern_sigaction vec;
3571 	boolean_t spawn_no_exec = FALSE;
3572 	boolean_t proc_transit_set = TRUE;
3573 	boolean_t proc_signal_set = TRUE;
3574 	boolean_t exec_done = FALSE;
3575 	os_reason_t exec_failure_reason = NULL;
3576 
3577 	struct exec_port_actions port_actions = { };
3578 	vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3579 	task_t old_task = current_task();
3580 	task_t new_task = NULL;
3581 	boolean_t should_release_proc_ref = FALSE;
3582 	void *inherit = NULL;
3583 	uint8_t crash_behavior = 0;
3584 	uint64_t crash_behavior_deadline = 0;
3585 #if CONFIG_EXCLAVES
3586 	char *task_conclave_id = NULL;
3587 #endif
3588 #if CONFIG_PERSONAS
3589 	struct _posix_spawn_persona_info *px_persona = NULL;
3590 #endif
3591 	struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3592 	struct {
3593 		struct image_params imgp;
3594 		struct vnode_attr va;
3595 		struct vnode_attr origva;
3596 	} *__spawn_data;
3597 
3598 	/*
3599 	 * Allocate a big chunk for locals instead of using stack since these
3600 	 * structures are pretty big.
3601 	 */
3602 	__spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3603 	if (__spawn_data == NULL) {
3604 		error = ENOMEM;
3605 		goto bad;
3606 	}
3607 	imgp = &__spawn_data->imgp;
3608 	vap = &__spawn_data->va;
3609 	origvap = &__spawn_data->origva;
3610 
3611 	/* Initialize the common data in the image_params structure */
3612 	imgp->ip_user_fname = uap->path;
3613 	imgp->ip_user_argv = uap->argv;
3614 	imgp->ip_user_envv = uap->envp;
3615 	imgp->ip_vattr = vap;
3616 	imgp->ip_origvattr = origvap;
3617 	imgp->ip_vfs_context = &context;
3618 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3619 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3620 	imgp->ip_mac_return = 0;
3621 	imgp->ip_px_persona = NULL;
3622 	imgp->ip_px_pcred_info = NULL;
3623 	imgp->ip_cs_error = OS_REASON_NULL;
3624 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3625 	imgp->ip_subsystem_root_path = NULL;
3626 	imgp->ip_inherited_shared_region_id = NULL;
3627 	imgp->ip_inherited_jop_pid = 0;
3628 	uthread_set_exec_data(current_uthread(), imgp);
3629 
3630 	if (uap->adesc != USER_ADDR_NULL) {
3631 		if (is_64) {
3632 			error = copyin(uap->adesc, &px_args, sizeof(px_args));
3633 		} else {
3634 			struct user32__posix_spawn_args_desc px_args32;
3635 
3636 			error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3637 
3638 			/*
3639 			 * Convert arguments descriptor from external 32 bit
3640 			 * representation to internal 64 bit representation
3641 			 */
3642 			px_args.attr_size = px_args32.attr_size;
3643 			px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3644 			px_args.file_actions_size = px_args32.file_actions_size;
3645 			px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3646 			px_args.port_actions_size = px_args32.port_actions_size;
3647 			px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3648 			px_args.mac_extensions_size = px_args32.mac_extensions_size;
3649 			px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3650 			px_args.coal_info_size = px_args32.coal_info_size;
3651 			px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3652 			px_args.persona_info_size = px_args32.persona_info_size;
3653 			px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3654 			px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3655 			px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3656 			px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3657 			px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3658 			px_args.conclave_id_size = px_args32.conclave_id_size;
3659 			px_args.conclave_id = CAST_USER_ADDR_T(px_args32.conclave_id);
3660 		}
3661 		if (error) {
3662 			goto bad;
3663 		}
3664 
3665 		if (px_args.attr_size != 0) {
3666 			/*
3667 			 * We are not copying the port_actions pointer,
3668 			 * because we already have it from px_args.
3669 			 * This is a bit fragile: <rdar://problem/16427422>
3670 			 */
3671 
3672 			if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3673 				goto bad;
3674 			}
3675 
3676 			imgp->ip_px_sa = &px_sa;
3677 		}
3678 		if (px_args.file_actions_size != 0) {
3679 			/* Limit file_actions to allowed number of open files */
3680 			size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3681 
3682 			if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3683 			    maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3684 				error = EINVAL;
3685 				goto bad;
3686 			}
3687 
3688 			px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3689 			if (px_sfap == NULL) {
3690 				error = ENOMEM;
3691 				goto bad;
3692 			}
3693 			imgp->ip_px_sfa = px_sfap;
3694 
3695 			if ((error = copyin(px_args.file_actions, px_sfap,
3696 			    px_args.file_actions_size)) != 0) {
3697 				goto bad;
3698 			}
3699 
3700 			/* Verify that the action count matches the struct size */
3701 			size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3702 			if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3703 				error = EINVAL;
3704 				goto bad;
3705 			}
3706 		}
3707 		if (px_args.port_actions_size != 0) {
3708 			/* Limit port_actions to one page of data */
3709 			if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3710 			    px_args.port_actions_size > PAGE_SIZE) {
3711 				error = EINVAL;
3712 				goto bad;
3713 			}
3714 
3715 			px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3716 			if (px_spap == NULL) {
3717 				error = ENOMEM;
3718 				goto bad;
3719 			}
3720 			imgp->ip_px_spa = px_spap;
3721 
3722 			if ((error = copyin(px_args.port_actions, px_spap,
3723 			    px_args.port_actions_size)) != 0) {
3724 				goto bad;
3725 			}
3726 
3727 			/* Verify that the action count matches the struct size */
3728 			size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3729 			if (pasize == 0 || pasize != px_args.port_actions_size) {
3730 				error = EINVAL;
3731 				goto bad;
3732 			}
3733 		}
3734 #if CONFIG_PERSONAS
3735 		/* copy in the persona info */
3736 		if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3737 			/* for now, we need the exact same struct in user space */
3738 			if (px_args.persona_info_size != sizeof(*px_persona)) {
3739 				error = ERANGE;
3740 				goto bad;
3741 			}
3742 
3743 			px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3744 			if (px_persona == NULL) {
3745 				error = ENOMEM;
3746 				goto bad;
3747 			}
3748 			imgp->ip_px_persona = px_persona;
3749 
3750 			if ((error = copyin(px_args.persona_info, px_persona,
3751 			    px_args.persona_info_size)) != 0) {
3752 				goto bad;
3753 			}
3754 			if ((error = spawn_validate_persona(px_persona)) != 0) {
3755 				goto bad;
3756 			}
3757 		}
3758 #endif
3759 		/* copy in the posix cred info */
3760 		if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
3761 			/* for now, we need the exact same struct in user space */
3762 			if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
3763 				error = ERANGE;
3764 				goto bad;
3765 			}
3766 
3767 			if (!kauth_cred_issuser(kauth_cred_get())) {
3768 				error = EPERM;
3769 				goto bad;
3770 			}
3771 
3772 			px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
3773 			if (px_pcred_info == NULL) {
3774 				error = ENOMEM;
3775 				goto bad;
3776 			}
3777 			imgp->ip_px_pcred_info = px_pcred_info;
3778 
3779 			if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
3780 			    px_args.posix_cred_info_size)) != 0) {
3781 				goto bad;
3782 			}
3783 
3784 			if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3785 				if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
3786 					error = EINVAL;
3787 					goto bad;
3788 				}
3789 			}
3790 		}
3791 #if CONFIG_MACF
3792 		if (px_args.mac_extensions_size != 0) {
3793 			if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
3794 				goto bad;
3795 			}
3796 		}
3797 #endif /* CONFIG_MACF */
3798 		if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
3799 			/*
3800 			 * If a valid-looking subsystem root has been
3801 			 * specified...
3802 			 */
3803 			if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
3804 				/*
3805 				 * ...AND the parent has the entitlement, copy
3806 				 * the subsystem root path in.
3807 				 */
3808 				subsystem_root_path = zalloc_flags(ZV_NAMEI,
3809 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3810 
3811 				if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
3812 					goto bad;
3813 				}
3814 
3815 				/* Paranoia */
3816 				subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
3817 			}
3818 		}
3819 #if CONFIG_EXCLAVES
3820 		if ((px_args.conclave_id_size > 0) && (px_args.conclave_id_size <= MAXCONCLAVENAME) &&
3821 		    (exclaves_get_status() == EXCLAVES_STATUS_AVAILABLE)) {
3822 			if (px_args.conclave_id) {
3823 				if (imgp->ip_px_sa != NULL && (px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3824 					/* Conclave id could be set only for true spawn */
3825 					error = EINVAL;
3826 					goto bad;
3827 				}
3828 				task_conclave_id = kalloc_data(MAXCONCLAVENAME,
3829 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
3830 				if ((error = copyin(px_args.conclave_id, task_conclave_id, MAXCONCLAVENAME))) {
3831 					goto bad;
3832 				}
3833 				task_conclave_id[MAXCONCLAVENAME - 1] = 0;
3834 			}
3835 		}
3836 #endif
3837 	}
3838 
3839 	if (IOTaskHasEntitlement(old_task, SPAWN_SET_PANIC_CRASH_BEHAVIOR)) {
3840 		/* Truncate to uint8_t since we only support 2 flags for now */
3841 		crash_behavior = (uint8_t)px_sa.psa_crash_behavior;
3842 		crash_behavior_deadline = px_sa.psa_crash_behavior_deadline;
3843 	}
3844 
3845 	/* set uthread to parent */
3846 	uthread = current_uthread();
3847 
3848 	/*
3849 	 * <rdar://6640530>; this does not result in a behaviour change
3850 	 * relative to Leopard, so there should not be any existing code
3851 	 * which depends on it.
3852 	 */
3853 
3854 	if (imgp->ip_px_sa != NULL) {
3855 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
3856 		if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
3857 			imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
3858 		}
3859 #if (DEVELOPMENT || DEBUG)
3860 		if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
3861 			imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
3862 		}
3863 #endif
3864 
3865 		if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
3866 			goto bad;
3867 		}
3868 	}
3869 
3870 	/*
3871 	 * If we don't have the extension flag that turns "posix_spawn()"
3872 	 * into "execve() with options", then we will be creating a new
3873 	 * process which does not inherit memory from the parent process,
3874 	 * which is one of the most expensive things about using fork()
3875 	 * and execve().
3876 	 */
3877 	if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3878 		/* Set the new task's coalition, if it is requested.  */
3879 		coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
3880 #if CONFIG_COALITIONS
3881 		int i, ncoals;
3882 		kern_return_t kr = KERN_SUCCESS;
3883 		struct _posix_spawn_coalition_info coal_info;
3884 		int coal_role[COALITION_NUM_TYPES];
3885 
3886 		if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
3887 			goto do_fork1;
3888 		}
3889 
3890 		memset(&coal_info, 0, sizeof(coal_info));
3891 
3892 		if (px_args.coal_info_size > sizeof(coal_info)) {
3893 			px_args.coal_info_size = sizeof(coal_info);
3894 		}
3895 		error = copyin(px_args.coal_info,
3896 		    &coal_info, px_args.coal_info_size);
3897 		if (error != 0) {
3898 			goto bad;
3899 		}
3900 
3901 		ncoals = 0;
3902 		for (i = 0; i < COALITION_NUM_TYPES; i++) {
3903 			uint64_t cid = coal_info.psci_info[i].psci_id;
3904 			if (cid != 0) {
3905 				/*
3906 				 * don't allow tasks which are not in a
3907 				 * privileged coalition to spawn processes
3908 				 * into coalitions other than their own
3909 				 */
3910 				if (!task_is_in_privileged_coalition(proc_task(p), i) &&
3911 				    !IOTaskHasEntitlement(proc_task(p), COALITION_SPAWN_ENTITLEMENT)) {
3912 					coal_dbg("ERROR: %d not in privilegd "
3913 					    "coalition of type %d",
3914 					    proc_getpid(p), i);
3915 					spawn_coalitions_release_all(coal);
3916 					error = EPERM;
3917 					goto bad;
3918 				}
3919 
3920 				coal_dbg("searching for coalition id:%llu", cid);
3921 				/*
3922 				 * take a reference and activation on the
3923 				 * coalition to guard against free-while-spawn
3924 				 * races
3925 				 */
3926 				coal[i] = coalition_find_and_activate_by_id(cid);
3927 				if (coal[i] == COALITION_NULL) {
3928 					coal_dbg("could not find coalition id:%llu "
3929 					    "(perhaps it has been terminated or reaped)", cid);
3930 					/*
3931 					 * release any other coalition's we
3932 					 * may have a reference to
3933 					 */
3934 					spawn_coalitions_release_all(coal);
3935 					error = ESRCH;
3936 					goto bad;
3937 				}
3938 				if (coalition_type(coal[i]) != i) {
3939 					coal_dbg("coalition with id:%lld is not of type:%d"
3940 					    " (it's type:%d)", cid, i, coalition_type(coal[i]));
3941 					spawn_coalitions_release_all(coal);
3942 					error = ESRCH;
3943 					goto bad;
3944 				}
3945 				coal_role[i] = coal_info.psci_info[i].psci_role;
3946 				ncoals++;
3947 			}
3948 		}
3949 		if (ncoals < COALITION_NUM_TYPES) {
3950 			/*
3951 			 * If the user is attempting to spawn into a subset of
3952 			 * the known coalition types, then make sure they have
3953 			 * _at_least_ specified a resource coalition. If not,
3954 			 * the following fork1() call will implicitly force an
3955 			 * inheritance from 'p' and won't actually spawn the
3956 			 * new task into the coalitions the user specified.
3957 			 * (also the call to coalitions_set_roles will panic)
3958 			 */
3959 			if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
3960 				spawn_coalitions_release_all(coal);
3961 				error = EINVAL;
3962 				goto bad;
3963 			}
3964 		}
3965 do_fork1:
3966 #endif /* CONFIG_COALITIONS */
3967 
3968 		/*
3969 		 * note that this will implicitly inherit the
3970 		 * caller's persona (if it exists)
3971 		 */
3972 		error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
3973 		/* returns a thread and task reference */
3974 
3975 		if (error == 0) {
3976 			new_task = get_threadtask(imgp->ip_new_thread);
3977 		}
3978 #if CONFIG_COALITIONS
3979 		/* set the roles of this task within each given coalition */
3980 		if (error == 0) {
3981 			kr = coalitions_set_roles(coal, new_task, coal_role);
3982 			if (kr != KERN_SUCCESS) {
3983 				error = EINVAL;
3984 			}
3985 			if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
3986 			    MACH_COALITION_ADOPT))) {
3987 				for (i = 0; i < COALITION_NUM_TYPES; i++) {
3988 					if (coal[i] != COALITION_NULL) {
3989 						/*
3990 						 * On 32-bit targets, uniqueid
3991 						 * will get truncated to 32 bits
3992 						 */
3993 						KDBG_RELEASE(MACHDBG_CODE(
3994 							    DBG_MACH_COALITION,
3995 							    MACH_COALITION_ADOPT),
3996 						    coalition_id(coal[i]),
3997 						    get_task_uniqueid(new_task));
3998 					}
3999 				}
4000 			}
4001 		}
4002 
4003 		/* drop our references and activations - fork1() now holds them */
4004 		spawn_coalitions_release_all(coal);
4005 #endif /* CONFIG_COALITIONS */
4006 		if (error != 0) {
4007 			goto bad;
4008 		}
4009 		imgp->ip_flags |= IMGPF_SPAWN;  /* spawn w/o exec */
4010 		spawn_no_exec = TRUE;           /* used in later tests */
4011 	} else {
4012 		/* Adjust the user proc count */
4013 		(void)chgproccnt(kauth_getruid(), 1);
4014 		/*
4015 		 * For execve case, create a new proc, task and thread
4016 		 * but don't make the proc visible to userland. After
4017 		 * image activation, the new proc would take place of
4018 		 * the old proc in pid hash and other lists that make
4019 		 * the proc visible to the system.
4020 		 */
4021 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
4022 
4023 		/* task and thread ref returned by cloneproc */
4024 		if (imgp->ip_new_thread == NULL) {
4025 			(void)chgproccnt(kauth_getruid(), -1);
4026 			error = ENOMEM;
4027 			goto bad;
4028 		}
4029 
4030 		new_task = get_threadtask(imgp->ip_new_thread);
4031 		imgp->ip_flags |= IMGPF_EXEC;
4032 	}
4033 
4034 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
4035 
4036 	if (spawn_no_exec) {
4037 		/*
4038 		 * We had to wait until this point before firing the
4039 		 * proc:::create probe, otherwise p would not point to the
4040 		 * child process.
4041 		 */
4042 		DTRACE_PROC1(create, proc_t, p);
4043 	}
4044 	assert(p != NULL);
4045 
4046 	if (subsystem_root_path) {
4047 		/* If a subsystem root was specified, swap it in */
4048 		char * old_subsystem_root_path = p->p_subsystem_root_path;
4049 		p->p_subsystem_root_path = subsystem_root_path;
4050 		subsystem_root_path = old_subsystem_root_path;
4051 	}
4052 
4053 	p->p_crash_behavior = crash_behavior;
4054 	p->p_crash_behavior_deadline = crash_behavior_deadline;
4055 
4056 	p->p_crash_count = px_sa.psa_crash_count;
4057 	p->p_throttle_timeout = px_sa.psa_throttle_timeout;
4058 
4059 	/* We'll need the subsystem root for setting up Apple strings */
4060 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4061 
4062 	context.vc_thread = imgp->ip_new_thread;
4063 	context.vc_ucred = proc_ucred_unsafe(p);  /* in init */
4064 
4065 	/*
4066 	 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
4067 	 * to handle the file_actions.
4068 	 */
4069 
4070 	/* Has spawn file actions? */
4071 	if (imgp->ip_px_sfa != NULL) {
4072 		/*
4073 		 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
4074 		 * is handled in exec_handle_file_actions().
4075 		 */
4076 #if CONFIG_AUDIT
4077 		/*
4078 		 * The file actions auditing can overwrite the upath of
4079 		 * AUE_POSIX_SPAWN audit record.  Save the audit record.
4080 		 */
4081 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4082 		uthread->uu_ar = NULL;
4083 #endif
4084 		error = exec_handle_file_actions(imgp,
4085 		    imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
4086 #if CONFIG_AUDIT
4087 		/* Restore the AUE_POSIX_SPAWN audit record. */
4088 		uthread->uu_ar = save_uu_ar;
4089 #endif
4090 		if (error != 0) {
4091 			goto bad;
4092 		}
4093 	}
4094 
4095 	/* Has spawn port actions? */
4096 	if (imgp->ip_px_spa != NULL) {
4097 #if CONFIG_AUDIT
4098 		/*
4099 		 * Do the same for the port actions as we did for the file
4100 		 * actions.  Save the AUE_POSIX_SPAWN audit record.
4101 		 */
4102 		struct kaudit_record *save_uu_ar = uthread->uu_ar;
4103 		uthread->uu_ar = NULL;
4104 #endif
4105 		error = exec_handle_port_actions(imgp, &port_actions);
4106 #if CONFIG_AUDIT
4107 		/* Restore the AUE_POSIX_SPAWN audit record. */
4108 		uthread->uu_ar = save_uu_ar;
4109 #endif
4110 		if (error != 0) {
4111 			goto bad;
4112 		}
4113 	}
4114 
4115 	/* Has spawn attr? */
4116 	if (imgp->ip_px_sa != NULL) {
4117 		/*
4118 		 * Reset UID/GID to parent's RUID/RGID; This works only
4119 		 * because the operation occurs before the call
4120 		 * to exec_handle_sugid() by the image activator called
4121 		 * from exec_activate_image().
4122 		 *
4123 		 * POSIX requires that any setuid/setgid bits on the process
4124 		 * image will take precedence over the spawn attributes
4125 		 * (re)setting them.
4126 		 *
4127 		 * Modifications to p_ucred must be guarded using the
4128 		 * proc's ucred lock. This prevents others from accessing
4129 		 * a garbage credential.
4130 		 */
4131 		if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
4132 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
4133 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model){
4134 				return kauth_cred_model_setuidgid(model,
4135 				kauth_cred_getruid(parent),
4136 				kauth_cred_getrgid(parent));
4137 			});
4138 		}
4139 
4140 		if (imgp->ip_px_pcred_info) {
4141 			if (!spawn_no_exec) {
4142 				error = ENOTSUP;
4143 				goto bad;
4144 			}
4145 
4146 			error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
4147 			if (error != 0) {
4148 				goto bad;
4149 			}
4150 		}
4151 
4152 #if CONFIG_PERSONAS
4153 		if (imgp->ip_px_persona != NULL) {
4154 			if (!spawn_no_exec) {
4155 				error = ENOTSUP;
4156 				goto bad;
4157 			}
4158 
4159 			/*
4160 			 * If we were asked to spawn a process into a new persona,
4161 			 * do the credential switch now (which may override the UID/GID
4162 			 * inherit done just above). It's important to do this switch
4163 			 * before image activation both for reasons stated above, and
4164 			 * to ensure that the new persona has access to the image/file
4165 			 * being executed.
4166 			 */
4167 			error = spawn_persona_adopt(p, imgp->ip_px_persona);
4168 			if (error != 0) {
4169 				goto bad;
4170 			}
4171 		}
4172 #endif /* CONFIG_PERSONAS */
4173 #if !SECURE_KERNEL
4174 		/*
4175 		 * Disable ASLR for the spawned process.
4176 		 *
4177 		 * But only do so if we are not embedded + RELEASE.
4178 		 * While embedded allows for a boot-arg (-disable_aslr)
4179 		 * to deal with this (which itself is only honored on
4180 		 * DEVELOPMENT or DEBUG builds of xnu), it is often
4181 		 * useful or necessary to disable ASLR on a per-process
4182 		 * basis for unit testing and debugging.
4183 		 */
4184 		if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
4185 			OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
4186 		}
4187 #endif /* !SECURE_KERNEL */
4188 
4189 		/* Randomize high bits of ASLR slide */
4190 		if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
4191 			imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
4192 		}
4193 
4194 #if !SECURE_KERNEL
4195 		/*
4196 		 * Forcibly disallow execution from data pages for the spawned process
4197 		 * even if it would otherwise be permitted by the architecture default.
4198 		 */
4199 		if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
4200 			imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
4201 		}
4202 #endif /* !SECURE_KERNEL */
4203 
4204 #if     __has_feature(ptrauth_calls)
4205 		if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
4206 			imgp->ip_flags |= IMGPF_RESLIDE;
4207 		}
4208 #endif /* __has_feature(ptrauth_calls) */
4209 
4210 		if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
4211 		    POSIX_SPAWN_PROC_TYPE_DRIVER) {
4212 			imgp->ip_flags |= IMGPF_DRIVER;
4213 		}
4214 	}
4215 
4216 	/*
4217 	 * Disable ASLR during image activation.  This occurs either if the
4218 	 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
4219 	 * P_DISABLE_ASLR was inherited from the parent process.
4220 	 */
4221 	if (p->p_flag & P_DISABLE_ASLR) {
4222 		imgp->ip_flags |= IMGPF_DISABLE_ASLR;
4223 	}
4224 
4225 	/*
4226 	 * Clear transition flag so we won't hang if exec_activate_image() causes
4227 	 * an automount (and launchd does a proc sysctl to service it).
4228 	 *
4229 	 * <rdar://problem/6848672>, <rdar://problem/5959568>.
4230 	 */
4231 	proc_transend(p, 0);
4232 	proc_transit_set = 0;
4233 
4234 	if (!spawn_no_exec) {
4235 		/*
4236 		 * Clear the signal lock in case of exec, since
4237 		 * image activation uses psignal on child process.
4238 		 */
4239 		proc_signalend(p, 0);
4240 		proc_signal_set = 0;
4241 	}
4242 
4243 #if MAC_SPAWN   /* XXX */
4244 	if (uap->mac_p != USER_ADDR_NULL) {
4245 		error = mac_execve_enter(uap->mac_p, imgp);
4246 		if (error) {
4247 			goto bad;
4248 		}
4249 	}
4250 #endif
4251 
4252 
4253 	/*
4254 	 * Activate the image.
4255 	 * Warning: If activation failed after point of no return, it returns error
4256 	 * as 0 and pretends the call succeeded.
4257 	 */
4258 	error = exec_activate_image(imgp);
4259 #if defined(HAS_APPLE_PAC)
4260 	const uint8_t disable_user_jop = imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE;
4261 	ml_task_set_jop_pid_from_shared_region(new_task, disable_user_jop);
4262 	ml_task_set_disable_user_jop(new_task, disable_user_jop);
4263 	ml_thread_set_disable_user_jop(imgp->ip_new_thread, disable_user_jop);
4264 	ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4265 #endif
4266 
4267 
4268 	/*
4269 	 * If you've come here to add support for some new HW feature or some per-process or per-vmmap
4270 	 * or per-pmap flag that needs to be set before the process runs, or are in general lost, here
4271 	 * is some help. This summary was accurate as of Jul 2022. Use git log as needed. This comment
4272 	 * is here to prevent a recurrence of rdar://96307913
4273 	 *
4274 	 * In posix_spawn, following is what happens:
4275 	 * 1. Lots of prep and checking work
4276 	 * 2. Image activation via exec_activate_image(). The new task will get a new pmap here
4277 	 * 3. More prep work. (YOU ARE HERE)
4278 	 * 4. exec_resettextvp() is called
4279 	 * 5. At this point it is safe to check entitlements and code signatures
4280 	 * 6. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4281 	 *    The new thread is allowed to run in kernel. It cannot yet get to userland
4282 	 * 7. More things done here. This is your chance to affect the task before it runs in
4283 	 *    userspace
4284 	 * 8. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4285 	 *     The new thread is allowed to run in userland
4286 	 */
4287 
4288 	if (error == 0 && !spawn_no_exec) {
4289 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
4290 		/* proc ref returned */
4291 		should_release_proc_ref = TRUE;
4292 	}
4293 
4294 	if (error == 0) {
4295 		/* process completed the exec, but may have failed after point of no return */
4296 		exec_done = TRUE;
4297 	}
4298 
4299 #if CONFIG_EXCLAVES
4300 	if (!error && task_conclave_id != NULL) {
4301 		kern_return_t kr;
4302 		kr = task_add_conclave(new_task, imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
4303 		    task_conclave_id);
4304 		if (kr != KERN_SUCCESS) {
4305 			error = EINVAL;
4306 			goto bad;
4307 		}
4308 	}
4309 #endif
4310 
4311 	if (!error && imgp->ip_px_sa != NULL) {
4312 		thread_t child_thread = imgp->ip_new_thread;
4313 		uthread_t child_uthread = get_bsdthread_info(child_thread);
4314 
4315 		/*
4316 		 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
4317 		 * activation, else when image activation fails (before the point of no
4318 		 * return) would leave the parent process in a modified state.
4319 		 */
4320 		if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
4321 			struct setpgid_args spga;
4322 			spga.pid = proc_getpid(p);
4323 			spga.pgid = px_sa.psa_pgroup;
4324 			/*
4325 			 * Effectively, call setpgid() system call; works
4326 			 * because there are no pointer arguments.
4327 			 */
4328 			if ((error = setpgid(p, &spga, ival)) != 0) {
4329 				goto bad_px_sa;
4330 			}
4331 		}
4332 
4333 		if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
4334 			error = setsid_internal(p);
4335 			if (error != 0) {
4336 				goto bad_px_sa;
4337 			}
4338 		}
4339 
4340 		/*
4341 		 * If we have a spawn attr, and it contains signal related flags,
4342 		 * the we need to process them in the "context" of the new child
4343 		 * process, so we have to process it following image activation,
4344 		 * prior to making the thread runnable in user space.  This is
4345 		 * necessitated by some signal information being per-thread rather
4346 		 * than per-process, and we don't have the new allocation in hand
4347 		 * until after the image is activated.
4348 		 */
4349 
4350 		/*
4351 		 * Mask a list of signals, instead of them being unmasked, if
4352 		 * they were unmasked in the parent; note that some signals
4353 		 * are not maskable.
4354 		 */
4355 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
4356 			child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
4357 		}
4358 		/*
4359 		 * Default a list of signals instead of ignoring them, if
4360 		 * they were ignored in the parent.  Note that we pass
4361 		 * spawn_no_exec to setsigvec() to indicate that we called
4362 		 * fork1() and therefore do not need to call proc_signalstart()
4363 		 * internally.
4364 		 */
4365 		if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
4366 			vec.sa_handler = SIG_DFL;
4367 			vec.sa_tramp = 0;
4368 			vec.sa_mask = 0;
4369 			vec.sa_flags = 0;
4370 			for (sig = 1; sig < NSIG; sig++) {
4371 				if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
4372 					error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
4373 				}
4374 			}
4375 		}
4376 
4377 		/*
4378 		 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
4379 		 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
4380 		 * limit.
4381 		 *
4382 		 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
4383 		 */
4384 		if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
4385 			/*
4386 			 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
4387 			 * an entitlement to configure the monitor a certain way seems silly, since
4388 			 * whomever is turning it on could just as easily choose not to do so.
4389 			 */
4390 			error = proc_set_task_ruse_cpu(proc_task(p),
4391 			    TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
4392 			    (uint8_t)px_sa.psa_cpumonitor_percent,
4393 			    px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
4394 			    0, TRUE);
4395 		}
4396 
4397 
4398 		if (px_pcred_info &&
4399 		    (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
4400 			/*
4401 			 * setlogin() must happen after setsid()
4402 			 */
4403 			setlogin_internal(p, px_pcred_info->pspci_login);
4404 		}
4405 
4406 bad_px_sa:
4407 		if (error != 0) {
4408 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
4409 			    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR, 0, 0);
4410 			exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR);
4411 		}
4412 	}
4413 
4414 bad:
4415 
4416 	if (error == 0) {
4417 		/* reset delay idle sleep status if set */
4418 #if CONFIG_DELAY_IDLE_SLEEP
4419 		if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
4420 			OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
4421 		}
4422 #endif /* CONFIG_DELAY_IDLE_SLEEP */
4423 		/* upon  successful spawn, re/set the proc control state */
4424 		if (imgp->ip_px_sa != NULL) {
4425 			switch (px_sa.psa_pcontrol) {
4426 			case POSIX_SPAWN_PCONTROL_THROTTLE:
4427 				p->p_pcaction = P_PCTHROTTLE;
4428 				break;
4429 			case POSIX_SPAWN_PCONTROL_SUSPEND:
4430 				p->p_pcaction = P_PCSUSP;
4431 				break;
4432 			case POSIX_SPAWN_PCONTROL_KILL:
4433 				p->p_pcaction = P_PCKILL;
4434 				break;
4435 			case POSIX_SPAWN_PCONTROL_NONE:
4436 			default:
4437 				p->p_pcaction = 0;
4438 				break;
4439 			}
4440 			;
4441 		}
4442 		exec_resettextvp(p, imgp);
4443 
4444 		/*
4445 		 * Enable new task IPC access if exec_activate_image() returned an
4446 		 * active task. (Checks active bit in ipc_task_enable() under lock).
4447 		 * Must enable after resettextvp so that task port policies are not evaluated
4448 		 * until the csblob in the textvp is accurately reflected.
4449 		 */
4450 		ipc_task_enable(new_task);
4451 
4452 		/* Set task exception ports now that we can check entitlements */
4453 		if (imgp->ip_px_spa != NULL) {
4454 			error = exec_handle_exception_port_actions(imgp, &port_actions);
4455 		}
4456 
4457 #if CONFIG_MEMORYSTATUS
4458 		/* Set jetsam priority for DriverKit processes */
4459 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4460 			px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
4461 		}
4462 
4463 		/* Has jetsam attributes? */
4464 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
4465 			/*
4466 			 * With 2-level high-water-mark support, POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no
4467 			 * longer relevant, as background limits are described via the inactive limit slots.
4468 			 *
4469 			 * That said, however, if the POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in,
4470 			 * we attempt to mimic previous behavior by forcing the BG limit data into the
4471 			 * inactive/non-fatal mode and force the active slots to hold system_wide/fatal mode.
4472 			 */
4473 
4474 			if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
4475 				memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
4476 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
4477 				    TRUE,
4478 				    -1, TRUE,
4479 				    px_sa.psa_memlimit_inactive, FALSE);
4480 			} else {
4481 				memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
4482 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
4483 				    TRUE,
4484 				    px_sa.psa_memlimit_active,
4485 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL),
4486 				    px_sa.psa_memlimit_inactive,
4487 				    (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL));
4488 			}
4489 		}
4490 
4491 		/* Has jetsam relaunch behavior? */
4492 		if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
4493 			/*
4494 			 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
4495 			 * This data would be used by the jetsam subsystem to determine the position and protection
4496 			 * offered to this process on dirty -> clean transitions.
4497 			 */
4498 			int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
4499 			switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
4500 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
4501 				relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
4502 				break;
4503 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
4504 				relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
4505 				break;
4506 			case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
4507 				relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
4508 				break;
4509 			default:
4510 				break;
4511 			}
4512 			memorystatus_relaunch_flags_update(p, relaunch_flags);
4513 		}
4514 
4515 #endif /* CONFIG_MEMORYSTATUS */
4516 		if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
4517 			task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
4518 		}
4519 
4520 #if CONFIG_PROC_RESOURCE_LIMITS
4521 		if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
4522 			task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
4523 			    (uint32_t)px_sa.psa_port_hard_limit);
4524 		}
4525 
4526 		if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
4527 			proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
4528 			    (int)px_sa.psa_filedesc_hard_limit);
4529 		}
4530 		if (imgp->ip_px_sa != NULL && (px_sa.psa_kqworkloop_soft_limit > 0 || px_sa.psa_kqworkloop_hard_limit > 0)) {
4531 			proc_set_kqworkloop_limits(p, (int)px_sa.psa_kqworkloop_soft_limit,
4532 			    (int)px_sa.psa_kqworkloop_hard_limit);
4533 		}
4534 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
4535 
4536 		/* Disable wakeup monitoring for DriverKit processes */
4537 		if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4538 			uint32_t      flags = WAKEMON_DISABLE;
4539 			task_wakeups_monitor_ctl(new_task, &flags, NULL);
4540 		}
4541 	}
4542 
4543 
4544 	/*
4545 	 * If we successfully called fork1() or cloneproc, we always need
4546 	 * to do this. This is because we come back from that call with
4547 	 * signals blocked in the child, and we have to unblock them, for exec
4548 	 * case they are unblocked before activation, but for true spawn case
4549 	 * we want to wait until after we've performed any spawn actions.
4550 	 * This has to happen before process_signature(), which uses psignal.
4551 	 */
4552 	if (proc_transit_set) {
4553 		proc_transend(p, 0);
4554 	}
4555 
4556 	/*
4557 	 * Drop the signal lock on the child which was taken on our
4558 	 * behalf by forkproc()/cloneproc() to prevent signals being
4559 	 * received by the child in a partially constructed state.
4560 	 */
4561 	if (proc_signal_set) {
4562 		proc_signalend(p, 0);
4563 	}
4564 
4565 	if (error == 0) {
4566 		/*
4567 		 * We need to initialize the bank context behind the protection of
4568 		 * the proc_trans lock to prevent a race with exit. We can't do this during
4569 		 * exec_activate_image because task_bank_init checks entitlements that
4570 		 * aren't loaded until subsequent calls (including exec_resettextvp).
4571 		 */
4572 		error = proc_transstart(p, 0, 0);
4573 
4574 		if (error == 0) {
4575 			task_bank_init(new_task);
4576 			proc_transend(p, 0);
4577 		}
4578 
4579 #if __arm64__
4580 		proc_footprint_entitlement_hacks(p, new_task);
4581 #endif /* __arm64__ */
4582 
4583 #if XNU_TARGET_OS_OSX
4584 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4585 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4586 			vm_map_single_jit(get_task_map(new_task));
4587 		}
4588 #endif /* XNU_TARGET_OS_OSX */
4589 
4590 #if __has_feature(ptrauth_calls)
4591 		task_set_pac_exception_fatal_flag(new_task);
4592 #endif /* __has_feature(ptrauth_calls) */
4593 		task_set_jit_exception_fatal_flag(new_task);
4594 	}
4595 
4596 	/* Inherit task role from old task to new task for exec */
4597 	if (error == 0 && !spawn_no_exec) {
4598 		proc_inherit_task_role(new_task, old_task);
4599 	}
4600 
4601 #if CONFIG_ARCADE
4602 	if (error == 0) {
4603 		/*
4604 		 * Check to see if we need to trigger an arcade upcall AST now
4605 		 * that the vnode has been reset on the task.
4606 		 */
4607 		arcade_prepare(new_task, imgp->ip_new_thread);
4608 	}
4609 #endif /* CONFIG_ARCADE */
4610 
4611 	if (error == 0) {
4612 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
4613 	}
4614 
4615 	/* Clear the initial wait on the thread before handling spawn policy */
4616 	if (imgp && imgp->ip_new_thread) {
4617 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4618 	}
4619 
4620 	/*
4621 	 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4622 	 * and bind any portwatch ports to the new task.
4623 	 * This must be done after the exec so that the child's thread is ready,
4624 	 * and after the in transit state has been released, because priority is
4625 	 * dropped here so we need to be prepared for a potentially long preemption interval
4626 	 *
4627 	 * TODO: Consider splitting this up into separate phases
4628 	 */
4629 	if (error == 0 && imgp->ip_px_sa != NULL) {
4630 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4631 
4632 		error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4633 		    psa->psa_darwin_role, &port_actions);
4634 	}
4635 
4636 	/* Transfer the turnstile watchport boost to new task if in exec */
4637 	if (error == 0 && !spawn_no_exec) {
4638 		task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4639 	}
4640 
4641 	if (error == 0 && imgp->ip_px_sa != NULL) {
4642 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4643 
4644 		if (psa->psa_no_smt) {
4645 			task_set_no_smt(new_task);
4646 		}
4647 		if (psa->psa_tecs) {
4648 			task_set_tecs(new_task);
4649 		}
4650 	}
4651 
4652 	if (error == 0 && imgp->ip_px_sa != NULL) {
4653 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4654 
4655 		if (psa->psa_options & PSA_OPTION_DATALESS_IOPOLICY) {
4656 			struct _iopol_param_t iop_param = {
4657 				.iop_scope = IOPOL_SCOPE_PROCESS,
4658 				.iop_iotype = IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES,
4659 				.iop_policy = psa->psa_dataless_iopolicy,
4660 			};
4661 			error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_SET, iop_param.iop_scope,
4662 			    iop_param.iop_policy, &iop_param);
4663 		}
4664 	}
4665 
4666 	if (error == 0) {
4667 		/* Apply the main thread qos */
4668 		thread_t main_thread = imgp->ip_new_thread;
4669 		task_set_main_thread_qos(new_task, main_thread);
4670 	}
4671 
4672 	/*
4673 	 * Release any ports we kept around for binding to the new task
4674 	 * We need to release the rights even if the posix_spawn has failed.
4675 	 */
4676 	if (imgp->ip_px_spa != NULL) {
4677 		exec_port_actions_destroy(&port_actions);
4678 	}
4679 
4680 	/*
4681 	 * We have to delay operations which might throw a signal until after
4682 	 * the signals have been unblocked; however, we want that to happen
4683 	 * after exec_resettextvp() so that the textvp is correct when they
4684 	 * fire.
4685 	 */
4686 	if (error == 0) {
4687 		error = process_signature(p, imgp);
4688 
4689 		/*
4690 		 * Pay for our earlier safety; deliver the delayed signals from
4691 		 * the incomplete spawn process now that it's complete.
4692 		 */
4693 		if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4694 			psignal_vfork(p, proc_task(p), imgp->ip_new_thread, SIGTRAP);
4695 		}
4696 
4697 		if (error == 0 && !spawn_no_exec) {
4698 			KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4699 			    proc_getpid(p));
4700 		}
4701 	}
4702 
4703 	if (spawn_no_exec) {
4704 		/* flag the 'fork' has occurred */
4705 		proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4706 	}
4707 
4708 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
4709 	if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4710 		proc_knote(p, NOTE_EXEC);
4711 	}
4712 
4713 	if (imgp != NULL) {
4714 		uthread_set_exec_data(current_uthread(), NULL);
4715 		if (imgp->ip_vp) {
4716 			vnode_put(imgp->ip_vp);
4717 		}
4718 		if (imgp->ip_scriptvp) {
4719 			vnode_put(imgp->ip_scriptvp);
4720 		}
4721 		if (imgp->ip_strings) {
4722 			execargs_free(imgp);
4723 		}
4724 		if (imgp->ip_free_map) {
4725 			/* Free the map after dropping iocount on vnode to avoid deadlock */
4726 			vm_map_deallocate(imgp->ip_free_map);
4727 		}
4728 		kfree_data(imgp->ip_px_sfa,
4729 		    px_args.file_actions_size);
4730 		kfree_data(imgp->ip_px_spa,
4731 		    px_args.port_actions_size);
4732 #if CONFIG_PERSONAS
4733 		kfree_data(imgp->ip_px_persona,
4734 		    px_args.persona_info_size);
4735 #endif
4736 		kfree_data(imgp->ip_px_pcred_info,
4737 		    px_args.posix_cred_info_size);
4738 
4739 		if (subsystem_root_path != NULL) {
4740 			zfree(ZV_NAMEI, subsystem_root_path);
4741 		}
4742 #if CONFIG_MACF
4743 		struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
4744 		kfree_data(px_s->array, px_args.mac_extensions_size);
4745 		kfree_data(px_s->data, (vm_size_t)px_s->datalen);
4746 
4747 		if (imgp->ip_execlabelp) {
4748 			mac_cred_label_free(imgp->ip_execlabelp);
4749 			imgp->ip_execlabelp = NULL;
4750 		}
4751 		if (imgp->ip_scriptlabelp) {
4752 			mac_vnode_label_free(imgp->ip_scriptlabelp);
4753 			imgp->ip_scriptlabelp = NULL;
4754 		}
4755 		if (imgp->ip_cs_error != OS_REASON_NULL) {
4756 			os_reason_free(imgp->ip_cs_error);
4757 			imgp->ip_cs_error = OS_REASON_NULL;
4758 		}
4759 		if (imgp->ip_inherited_shared_region_id != NULL) {
4760 			kfree_data(imgp->ip_inherited_shared_region_id,
4761 			    strlen(imgp->ip_inherited_shared_region_id) + 1);
4762 			imgp->ip_inherited_shared_region_id = NULL;
4763 		}
4764 #endif
4765 	}
4766 
4767 #if CONFIG_DTRACE
4768 	if (spawn_no_exec) {
4769 		/*
4770 		 * In the original DTrace reference implementation,
4771 		 * posix_spawn() was a libc routine that just
4772 		 * did vfork(2) then exec(2).  Thus the proc::: probes
4773 		 * are very fork/exec oriented.  The details of this
4774 		 * in-kernel implementation of posix_spawn() is different
4775 		 * (while producing the same process-observable effects)
4776 		 * particularly w.r.t. errors, and which thread/process
4777 		 * is constructing what on behalf of whom.
4778 		 */
4779 		if (error) {
4780 			DTRACE_PROC1(spawn__failure, int, error);
4781 		} else {
4782 			DTRACE_PROC(spawn__success);
4783 			/*
4784 			 * Some DTrace scripts, e.g. newproc.d in
4785 			 * /usr/bin, rely on the the 'exec-success'
4786 			 * probe being fired in the child after the
4787 			 * new process image has been constructed
4788 			 * in order to determine the associated pid.
4789 			 *
4790 			 * So, even though the parent built the image
4791 			 * here, for compatibility, mark the new thread
4792 			 * so 'exec-success' fires on it as it leaves
4793 			 * the kernel.
4794 			 */
4795 			dtrace_thread_didexec(imgp->ip_new_thread);
4796 		}
4797 	} else {
4798 		if (error) {
4799 			DTRACE_PROC1(exec__failure, int, error);
4800 		} else {
4801 			dtrace_thread_didexec(imgp->ip_new_thread);
4802 		}
4803 	}
4804 
4805 	if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4806 		(*dtrace_proc_waitfor_hook)(p);
4807 	}
4808 #endif
4809 
4810 #if CONFIG_AUDIT
4811 	if (!error && AUDIT_ENABLED() && p) {
4812 		/* Add the CDHash of the new process to the audit record */
4813 		uint8_t *cdhash = cs_get_cdhash(p);
4814 		if (cdhash) {
4815 			AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4816 		}
4817 	}
4818 #endif
4819 
4820 	/* terminate the new task if exec failed  */
4821 	if (new_task != NULL && task_is_exec_copy(new_task)) {
4822 		task_terminate_internal(new_task);
4823 	}
4824 
4825 	if (exec_failure_reason && !spawn_no_exec) {
4826 		psignal_with_reason(p, SIGKILL, exec_failure_reason);
4827 		exec_failure_reason = NULL;
4828 	}
4829 
4830 	/* Return to both the parent and the child? */
4831 	if (imgp != NULL && spawn_no_exec) {
4832 		/*
4833 		 * If the parent wants the pid, copy it out
4834 		 */
4835 		if (error == 0 && pid != USER_ADDR_NULL) {
4836 			_Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
4837 			bool aligned = (pid & 3) == 0;
4838 			if (aligned) {
4839 				(void)copyout_atomic32(proc_getpid(p), pid);
4840 			} else {
4841 				(void)suword(pid, proc_getpid(p));
4842 			}
4843 		}
4844 		retval[0] = error;
4845 
4846 		/*
4847 		 * If we had an error, perform an internal reap ; this is
4848 		 * entirely safe, as we have a real process backing us.
4849 		 */
4850 		if (error) {
4851 			proc_list_lock();
4852 			p->p_listflag |= P_LIST_DEADPARENT;
4853 			proc_list_unlock();
4854 			proc_lock(p);
4855 			/* make sure no one else has killed it off... */
4856 			if (p->p_stat != SZOMB && p->exit_thread == NULL) {
4857 				p->exit_thread = current_thread();
4858 				p->p_posix_spawn_failed = true;
4859 				proc_unlock(p);
4860 				exit1(p, 1, (int *)NULL);
4861 			} else {
4862 				/* someone is doing it for us; just skip it */
4863 				proc_unlock(p);
4864 			}
4865 		}
4866 	}
4867 
4868 	/*
4869 	 * Do not terminate the current task, if proc_exec_switch_task did not
4870 	 * switch the tasks, terminating the current task without the switch would
4871 	 * result in loosing the SIGKILL status.
4872 	 */
4873 	if (task_did_exec(old_task)) {
4874 		/* Terminate the current task, since exec will start in new task */
4875 		task_terminate_internal(old_task);
4876 	}
4877 
4878 	/* Release the thread ref returned by cloneproc/fork1 */
4879 	if (imgp != NULL && imgp->ip_new_thread) {
4880 		/* clear the exec complete flag if there is an error before point of no-return */
4881 		uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
4882 		if (!spawn_no_exec && !exec_done && error != 0) {
4883 			clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
4884 		}
4885 		/* wake up the new thread */
4886 		task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
4887 		thread_deallocate(imgp->ip_new_thread);
4888 		imgp->ip_new_thread = NULL;
4889 	}
4890 
4891 	/* Release the ref returned by cloneproc/fork1 */
4892 	if (new_task) {
4893 		task_deallocate(new_task);
4894 		new_task = NULL;
4895 	}
4896 
4897 	if (should_release_proc_ref) {
4898 		proc_rele(p);
4899 	}
4900 
4901 	kfree_type(typeof(*__spawn_data), __spawn_data);
4902 
4903 	if (inherit != NULL) {
4904 		ipc_importance_release(inherit);
4905 	}
4906 
4907 #if CONFIG_EXCLAVES
4908 	if (task_conclave_id != NULL) {
4909 		kfree_data(task_conclave_id, MAXCONCLAVENAME);
4910 	}
4911 #endif
4912 
4913 	assert(spawn_no_exec || exec_failure_reason == NULL);
4914 	return error;
4915 }
4916 
4917 /*
4918  * proc_exec_switch_task
4919  *
4920  * Parameters:  old_proc		proc before exec
4921  *		new_proc		proc after exec
4922  *		old_task		task before exec
4923  *		new_task		task after exec
4924  *		imgp			image params
4925  *		inherit			resulting importance linkage
4926  *
4927  * Returns: proc.
4928  *
4929  * Note: The function will switch proc in pid hash from old proc to new proc.
4930  * The switch needs to happen after draining all proc refs and inside
4931  * a proc list lock. In the case of failure to switch the proc, which
4932  * might happen if the process received a SIGKILL or jetsam killed it,
4933  * it will make sure that the new tasks terminates. User proc ref returned
4934  * to caller.
4935  *
4936  * This function is called after point of no return, in the case
4937  * failure to switch, it will terminate the new task and swallow the
4938  * error and let the terminated process complete exec and die.
4939  */
4940 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)4941 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)
4942 {
4943 	boolean_t task_active;
4944 	boolean_t proc_active;
4945 	boolean_t thread_active;
4946 	boolean_t reparent_traced_child = FALSE;
4947 	thread_t old_thread = current_thread();
4948 	thread_t new_thread = imgp->ip_new_thread;
4949 
4950 	thread_set_exec_promotion(old_thread);
4951 	old_proc = proc_refdrain_will_exec(old_proc);
4952 
4953 	new_proc = proc_refdrain_will_exec(new_proc);
4954 	/* extra proc ref returned to the caller */
4955 
4956 	assert(get_threadtask(new_thread) == new_task);
4957 	task_active = task_is_active(new_task);
4958 	proc_active = !(old_proc->p_lflag & P_LEXIT);
4959 
4960 	/* Check if the current thread is not aborted due to SIGKILL */
4961 	thread_active = thread_is_active(old_thread);
4962 
4963 	/*
4964 	 * Do not switch the proc if the new task or proc is already terminated
4965 	 * as a result of error in exec past point of no return
4966 	 */
4967 	if (proc_active && task_active && thread_active) {
4968 		uthread_t new_uthread = get_bsdthread_info(new_thread);
4969 		uthread_t old_uthread = current_uthread();
4970 
4971 		/* Clear dispatchqueue and workloop ast offset */
4972 		new_proc->p_dispatchqueue_offset = 0;
4973 		new_proc->p_dispatchqueue_serialno_offset = 0;
4974 		new_proc->p_dispatchqueue_label_offset = 0;
4975 		new_proc->p_return_to_kernel_offset = 0;
4976 		new_proc->p_pthread_wq_quantum_offset = 0;
4977 
4978 		/* If old_proc is session leader, change the leader to new proc */
4979 		session_replace_leader(old_proc, new_proc);
4980 
4981 		proc_lock(old_proc);
4982 
4983 		/* Copy the signal state, dtrace state and set bsd ast on new thread */
4984 		act_set_astbsd(new_thread);
4985 		new_uthread->uu_siglist |= old_uthread->uu_siglist;
4986 		new_uthread->uu_siglist |= old_proc->p_siglist;
4987 		new_uthread->uu_sigwait = old_uthread->uu_sigwait;
4988 		new_uthread->uu_sigmask = old_uthread->uu_sigmask;
4989 		new_uthread->uu_oldmask = old_uthread->uu_oldmask;
4990 		new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
4991 #if CONFIG_DTRACE
4992 		new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
4993 		new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
4994 		new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
4995 		assert(new_uthread->t_dtrace_scratch == NULL);
4996 		new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
4997 
4998 		old_uthread->t_dtrace_sig = 0;
4999 		old_uthread->t_dtrace_stop = 0;
5000 		old_uthread->t_dtrace_resumepid = 0;
5001 		old_uthread->t_dtrace_scratch = NULL;
5002 #endif
5003 
5004 #if CONFIG_PROC_UDATA_STORAGE
5005 		new_proc->p_user_data = old_proc->p_user_data;
5006 #endif /* CONFIG_PROC_UDATA_STORAGE */
5007 
5008 		/* Copy the resource accounting info */
5009 		thread_copy_resource_info(new_thread, current_thread());
5010 
5011 		/* Clear the exit reason and signal state on old thread */
5012 		old_uthread->uu_exit_reason = NULL;
5013 		old_uthread->uu_siglist = 0;
5014 
5015 		task_set_did_exec_flag(old_task);
5016 		task_clear_exec_copy_flag(new_task);
5017 
5018 		task_copy_fields_for_exec(new_task, old_task);
5019 
5020 		/*
5021 		 * Need to transfer pending watch port boosts to the new task
5022 		 * while still making sure that the old task remains in the
5023 		 * importance linkage. Create an importance linkage from old task
5024 		 * to new task, then switch the task importance base of old task
5025 		 * and new task. After the switch the port watch boost will be
5026 		 * boosting the new task and new task will be donating importance
5027 		 * to old task.
5028 		 */
5029 		*inherit = ipc_importance_exec_switch_task(old_task, new_task);
5030 
5031 		/* Transfer parent's ptrace state to child */
5032 		new_proc->p_lflag &= ~(P_LTRACED | P_LSIGEXC | P_LNOATTACH);
5033 		new_proc->p_lflag |= (old_proc->p_lflag & (P_LTRACED | P_LSIGEXC | P_LNOATTACH));
5034 		new_proc->p_oppid = old_proc->p_oppid;
5035 
5036 		if (old_proc->p_pptr != new_proc->p_pptr) {
5037 			reparent_traced_child = TRUE;
5038 			new_proc->p_lflag |= P_LTRACE_WAIT;
5039 		}
5040 
5041 		proc_unlock(old_proc);
5042 
5043 		/* Update the list of proc knotes */
5044 		proc_transfer_knotes(old_proc, new_proc);
5045 
5046 		/* Update the proc interval timers */
5047 		proc_inherit_itimers(old_proc, new_proc);
5048 
5049 		proc_list_lock();
5050 
5051 		/* Insert the new proc in child list of parent proc */
5052 		p_reparentallchildren(old_proc, new_proc);
5053 
5054 		/* Switch proc in pid hash */
5055 		phash_replace_locked(old_proc, new_proc);
5056 
5057 		/* Transfer the shadow flag to old proc */
5058 		os_atomic_andnot(&new_proc->p_refcount, P_REF_SHADOW, relaxed);
5059 		os_atomic_or(&old_proc->p_refcount, P_REF_SHADOW, relaxed);
5060 
5061 		/* Change init proc if launchd exec */
5062 		if (old_proc == initproc) {
5063 			/* Take the ref on new proc after proc_refwake_did_exec */
5064 			initproc = new_proc;
5065 			/* Drop the proc ref on old proc */
5066 			proc_rele(old_proc);
5067 		}
5068 
5069 		proc_list_unlock();
5070 #if CONFIG_EXCLAVES
5071 		if (task_inherit_conclave(old_task, new_task, imgp->ip_vp,
5072 		    (int64_t)imgp->ip_arch_offset) != KERN_SUCCESS) {
5073 			task_terminate_internal(new_task);
5074 		}
5075 #endif
5076 	} else {
5077 		task_terminate_internal(new_task);
5078 	}
5079 
5080 	proc_refwake_did_exec(new_proc);
5081 	proc_refwake_did_exec(old_proc);
5082 
5083 	/* Take a ref on initproc if it changed */
5084 	if (new_proc == initproc) {
5085 		initproc = proc_ref(new_proc, false);
5086 		assert(initproc != PROC_NULL);
5087 	}
5088 
5089 	thread_clear_exec_promotion(old_thread);
5090 	proc_rele(old_proc);
5091 
5092 	if (reparent_traced_child) {
5093 		proc_t pp = proc_parent(old_proc);
5094 		assert(pp != PROC_NULL);
5095 
5096 		proc_reparentlocked(new_proc, pp, 1, 0);
5097 		proc_rele(pp);
5098 
5099 		proc_lock(new_proc);
5100 		new_proc->p_lflag &= ~P_LTRACE_WAIT;
5101 		proc_unlock(new_proc);
5102 	}
5103 
5104 	return new_proc;
5105 }
5106 
5107 /*
5108  * execve
5109  *
5110  * Parameters:	uap->fname		File name to exec
5111  *		uap->argp		Argument list
5112  *		uap->envp		Environment list
5113  *
5114  * Returns:	0			Success
5115  *	__mac_execve:EINVAL		Invalid argument
5116  *	__mac_execve:ENOTSUP		Invalid argument
5117  *	__mac_execve:EACCES		Permission denied
5118  *	__mac_execve:EINTR		Interrupted function
5119  *	__mac_execve:ENOMEM		Not enough space
5120  *	__mac_execve:EFAULT		Bad address
5121  *	__mac_execve:ENAMETOOLONG	Filename too long
5122  *	__mac_execve:ENOEXEC		Executable file format error
5123  *	__mac_execve:ETXTBSY		Text file busy [misuse of error code]
5124  *	__mac_execve:???
5125  *
5126  * TODO:	Dynamic linker header address on stack is copied via suword()
5127  */
5128 /* ARGSUSED */
5129 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)5130 execve(proc_t p, struct execve_args *uap, int32_t *retval)
5131 {
5132 	struct __mac_execve_args muap;
5133 	int err;
5134 
5135 	memoryshot(VM_EXECVE, DBG_FUNC_NONE);
5136 
5137 	muap.fname = uap->fname;
5138 	muap.argp = uap->argp;
5139 	muap.envp = uap->envp;
5140 	muap.mac_p = USER_ADDR_NULL;
5141 	err = __mac_execve(p, &muap, retval);
5142 
5143 	return err;
5144 }
5145 
5146 /*
5147  * __mac_execve
5148  *
5149  * Parameters:	uap->fname		File name to exec
5150  *		uap->argp		Argument list
5151  *		uap->envp		Environment list
5152  *		uap->mac_p		MAC label supplied by caller
5153  *
5154  * Returns:	0			Success
5155  *		EINVAL			Invalid argument
5156  *		ENOTSUP			Not supported
5157  *		ENOEXEC			Executable file format error
5158  *	exec_activate_image:EINVAL	Invalid argument
5159  *	exec_activate_image:EACCES	Permission denied
5160  *	exec_activate_image:EINTR	Interrupted function
5161  *	exec_activate_image:ENOMEM	Not enough space
5162  *	exec_activate_image:EFAULT	Bad address
5163  *	exec_activate_image:ENAMETOOLONG	Filename too long
5164  *	exec_activate_image:ENOEXEC	Executable file format error
5165  *	exec_activate_image:ETXTBSY	Text file busy [misuse of error code]
5166  *	exec_activate_image:EBADEXEC	The executable is corrupt/unknown
5167  *	exec_activate_image:???
5168  *	mac_execve_enter:???
5169  *
5170  * TODO:	Dynamic linker header address on stack is copied via suword()
5171  */
5172 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)5173 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
5174 {
5175 	struct image_params *imgp = NULL;
5176 	struct vnode_attr *vap = NULL;
5177 	struct vnode_attr *origvap = NULL;
5178 	int error;
5179 	int is_64 = IS_64BIT_PROCESS(p);
5180 	struct vfs_context context;
5181 	struct uthread  *uthread = NULL;
5182 	task_t old_task = current_task();
5183 	task_t new_task = NULL;
5184 	boolean_t should_release_proc_ref = FALSE;
5185 	boolean_t exec_done = FALSE;
5186 	void *inherit = NULL;
5187 	struct {
5188 		struct image_params imgp;
5189 		struct vnode_attr va;
5190 		struct vnode_attr origva;
5191 	} *__execve_data;
5192 
5193 	/* Allocate a big chunk for locals instead of using stack since these
5194 	 * structures a pretty big.
5195 	 */
5196 	__execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
5197 	if (__execve_data == NULL) {
5198 		error = ENOMEM;
5199 		goto exit_with_error;
5200 	}
5201 	imgp = &__execve_data->imgp;
5202 	vap = &__execve_data->va;
5203 	origvap = &__execve_data->origva;
5204 
5205 	/* Initialize the common data in the image_params structure */
5206 	imgp->ip_user_fname = uap->fname;
5207 	imgp->ip_user_argv = uap->argp;
5208 	imgp->ip_user_envv = uap->envp;
5209 	imgp->ip_vattr = vap;
5210 	imgp->ip_origvattr = origvap;
5211 	imgp->ip_vfs_context = &context;
5212 	imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
5213 	imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
5214 	imgp->ip_mac_return = 0;
5215 	imgp->ip_cs_error = OS_REASON_NULL;
5216 	imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
5217 	imgp->ip_subsystem_root_path = NULL;
5218 	uthread_set_exec_data(current_uthread(), imgp);
5219 
5220 #if CONFIG_MACF
5221 	if (uap->mac_p != USER_ADDR_NULL) {
5222 		error = mac_execve_enter(uap->mac_p, imgp);
5223 		if (error) {
5224 			goto exit_with_error;
5225 		}
5226 	}
5227 #endif
5228 	uthread = current_uthread();
5229 	{
5230 		imgp->ip_flags |= IMGPF_EXEC;
5231 
5232 		/* Adjust the user proc count */
5233 		(void)chgproccnt(kauth_getruid(), 1);
5234 		/*
5235 		 * For execve case, create a new proc, task and thread
5236 		 * but don't make the proc visible to userland. After
5237 		 * image activation, the new proc would take place of
5238 		 * the old proc in pid hash and other lists that make
5239 		 * the proc visible to the system.
5240 		 */
5241 		imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
5242 		/* task and thread ref returned by cloneproc */
5243 		if (imgp->ip_new_thread == NULL) {
5244 			(void)chgproccnt(kauth_getruid(), -1);
5245 			error = ENOMEM;
5246 			goto exit_with_error;
5247 		}
5248 
5249 		new_task = get_threadtask(imgp->ip_new_thread);
5250 	}
5251 
5252 	p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
5253 
5254 	context.vc_thread = imgp->ip_new_thread;
5255 	context.vc_ucred = kauth_cred_proc_ref(p);      /* XXX must NOT be kauth_cred_get() */
5256 
5257 	imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
5258 
5259 	proc_transend(p, 0);
5260 	proc_signalend(p, 0);
5261 
5262 
5263 	/*
5264 	 * Activate the image.
5265 	 * Warning: If activation failed after point of no return, it returns error
5266 	 * as 0 and pretends the call succeeded.
5267 	 */
5268 	error = exec_activate_image(imgp);
5269 	/* thread and task ref returned for vfexec case */
5270 
5271 	if (imgp->ip_new_thread != NULL) {
5272 		/*
5273 		 * task reference might be returned by exec_activate_image
5274 		 * for vfexec.
5275 		 */
5276 		new_task = get_threadtask(imgp->ip_new_thread);
5277 #if defined(HAS_APPLE_PAC)
5278 		ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5279 		ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5280 #endif
5281 	}
5282 
5283 	if (!error) {
5284 		p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
5285 		/* proc ref returned */
5286 		should_release_proc_ref = TRUE;
5287 	}
5288 
5289 	kauth_cred_unref(&context.vc_ucred);
5290 
5291 	if (!error) {
5292 		exec_done = TRUE;
5293 		assert(imgp->ip_new_thread != NULL);
5294 
5295 		exec_resettextvp(p, imgp);
5296 		/*
5297 		 * Enable new task IPC access if exec_activate_image() returned an
5298 		 * active task. (Checks active bit in ipc_task_enable() under lock).
5299 		 * Must enable after resettextvp so that task port policies are not evaluated
5300 		 * until the csblob in the textvp is accurately reflected.
5301 		 */
5302 		ipc_task_enable(new_task);
5303 		error = process_signature(p, imgp);
5304 	}
5305 
5306 #if defined(HAS_APPLE_PAC)
5307 	if (imgp->ip_new_thread && !error) {
5308 		ml_task_set_jop_pid_from_shared_region(new_task, imgp->ip_flags & IMGPF_NOJOP);
5309 		ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
5310 	}
5311 #endif /* defined(HAS_APPLE_PAC) */
5312 
5313 	/* flag exec has occurred, notify only if it has not failed due to FP Key error */
5314 	if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
5315 		proc_knote(p, NOTE_EXEC);
5316 	}
5317 
5318 	if (imgp->ip_vp != NULLVP) {
5319 		vnode_put(imgp->ip_vp);
5320 	}
5321 	if (imgp->ip_scriptvp != NULLVP) {
5322 		vnode_put(imgp->ip_scriptvp);
5323 	}
5324 	if (imgp->ip_free_map) {
5325 		/* Free the map after dropping iocount on vnode to avoid deadlock */
5326 		vm_map_deallocate(imgp->ip_free_map);
5327 	}
5328 	if (imgp->ip_strings) {
5329 		execargs_free(imgp);
5330 	}
5331 #if CONFIG_MACF
5332 	if (imgp->ip_execlabelp) {
5333 		mac_cred_label_free(imgp->ip_execlabelp);
5334 		imgp->ip_execlabelp = NULL;
5335 	}
5336 	if (imgp->ip_scriptlabelp) {
5337 		mac_vnode_label_free(imgp->ip_scriptlabelp);
5338 		imgp->ip_scriptlabelp = NULL;
5339 	}
5340 #endif
5341 	if (imgp->ip_cs_error != OS_REASON_NULL) {
5342 		os_reason_free(imgp->ip_cs_error);
5343 		imgp->ip_cs_error = OS_REASON_NULL;
5344 	}
5345 
5346 	if (!error) {
5347 		/*
5348 		 * We need to initialize the bank context behind the protection of
5349 		 * the proc_trans lock to prevent a race with exit. We can't do this during
5350 		 * exec_activate_image because task_bank_init checks entitlements that
5351 		 * aren't loaded until subsequent calls (including exec_resettextvp).
5352 		 */
5353 		error = proc_transstart(p, 0, 0);
5354 	}
5355 
5356 	if (!error) {
5357 		task_bank_init(new_task);
5358 		proc_transend(p, 0);
5359 
5360 		// Don't inherit crash behavior across exec
5361 		p->p_crash_behavior = 0;
5362 		p->p_crash_behavior_deadline = 0;
5363 
5364 #if __arm64__
5365 		proc_footprint_entitlement_hacks(p, new_task);
5366 #endif /* __arm64__ */
5367 
5368 #if XNU_TARGET_OS_OSX
5369 		if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
5370 			vm_map_single_jit(get_task_map(new_task));
5371 		}
5372 #endif /* XNU_TARGET_OS_OSX */
5373 
5374 		/* Sever any extant thread affinity */
5375 		thread_affinity_exec(current_thread());
5376 
5377 		/* Inherit task role from old task to new task for exec */
5378 		proc_inherit_task_role(new_task, old_task);
5379 
5380 		thread_t main_thread = imgp->ip_new_thread;
5381 
5382 		task_set_main_thread_qos(new_task, main_thread);
5383 
5384 #if __has_feature(ptrauth_calls)
5385 		task_set_pac_exception_fatal_flag(new_task);
5386 #endif /* __has_feature(ptrauth_calls) */
5387 		task_set_jit_exception_fatal_flag(new_task);
5388 
5389 #if CONFIG_ARCADE
5390 		/*
5391 		 * Check to see if we need to trigger an arcade upcall AST now
5392 		 * that the vnode has been reset on the task.
5393 		 */
5394 		arcade_prepare(new_task, imgp->ip_new_thread);
5395 #endif /* CONFIG_ARCADE */
5396 
5397 		proc_apply_jit_and_vm_policies(imgp, p, new_task);
5398 
5399 		if (vm_darkwake_mode == TRUE) {
5400 			/*
5401 			 * This process is being launched when the system
5402 			 * is in darkwake. So mark it specially. This will
5403 			 * cause all its pages to be entered in the background Q.
5404 			 */
5405 			task_set_darkwake_mode(new_task, vm_darkwake_mode);
5406 		}
5407 
5408 #if CONFIG_DTRACE
5409 		dtrace_thread_didexec(imgp->ip_new_thread);
5410 
5411 		if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5412 			(*dtrace_proc_waitfor_hook)(p);
5413 		}
5414 #endif
5415 
5416 #if CONFIG_AUDIT
5417 		if (!error && AUDIT_ENABLED() && p) {
5418 			/* Add the CDHash of the new process to the audit record */
5419 			uint8_t *cdhash = cs_get_cdhash(p);
5420 			if (cdhash) {
5421 				AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5422 			}
5423 		}
5424 #endif
5425 	} else {
5426 		DTRACE_PROC1(exec__failure, int, error);
5427 	}
5428 
5429 exit_with_error:
5430 
5431 	/* terminate the new task it if exec failed  */
5432 	if (new_task != NULL && task_is_exec_copy(new_task)) {
5433 		task_terminate_internal(new_task);
5434 	}
5435 
5436 	if (imgp != NULL) {
5437 		/* Clear the initial wait on the thread transferring watchports */
5438 		if (imgp->ip_new_thread) {
5439 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
5440 		}
5441 
5442 		/* Transfer the watchport boost to new task */
5443 		if (!error) {
5444 			task_transfer_turnstile_watchports(old_task,
5445 			    new_task, imgp->ip_new_thread);
5446 		}
5447 		/*
5448 		 * Do not terminate the current task, if proc_exec_switch_task did not
5449 		 * switch the tasks, terminating the current task without the switch would
5450 		 * result in loosing the SIGKILL status.
5451 		 */
5452 		if (task_did_exec(old_task)) {
5453 			/* Terminate the current task, since exec will start in new task */
5454 			task_terminate_internal(old_task);
5455 		}
5456 
5457 		/* Release the thread ref returned by cloneproc */
5458 		if (imgp->ip_new_thread) {
5459 			/* clear the exec complete flag if there is an error before point of no-return */
5460 			uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5461 			if (!exec_done && error != 0) {
5462 				clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5463 			}
5464 			/* wake up the new exec thread */
5465 			task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5466 			thread_deallocate(imgp->ip_new_thread);
5467 			imgp->ip_new_thread = NULL;
5468 		}
5469 	}
5470 
5471 	/* Release the ref returned by fork_create_child */
5472 	if (new_task) {
5473 		task_deallocate(new_task);
5474 		new_task = NULL;
5475 	}
5476 
5477 	if (should_release_proc_ref) {
5478 		proc_rele(p);
5479 	}
5480 
5481 	uthread_set_exec_data(current_uthread(), NULL);
5482 	kfree_type(typeof(*__execve_data), __execve_data);
5483 
5484 	if (inherit != NULL) {
5485 		ipc_importance_release(inherit);
5486 	}
5487 
5488 	return error;
5489 }
5490 
5491 
5492 /*
5493  * copyinptr
5494  *
5495  * Description:	Copy a pointer in from user space to a user_addr_t in kernel
5496  *		space, based on 32/64 bitness of the user space
5497  *
5498  * Parameters:	froma			User space address
5499  *		toptr			Address of kernel space user_addr_t
5500  *		ptr_size		4/8, based on 'froma' address space
5501  *
5502  * Returns:	0			Success
5503  *		EFAULT			Bad 'froma'
5504  *
5505  * Implicit returns:
5506  *		*ptr_size		Modified
5507  */
5508 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)5509 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
5510 {
5511 	int error;
5512 
5513 	if (ptr_size == 4) {
5514 		/* 64 bit value containing 32 bit address */
5515 		unsigned int i = 0;
5516 
5517 		error = copyin(froma, &i, 4);
5518 		*toptr = CAST_USER_ADDR_T(i);   /* SAFE */
5519 	} else {
5520 		error = copyin(froma, toptr, 8);
5521 	}
5522 	return error;
5523 }
5524 
5525 
5526 /*
5527  * copyoutptr
5528  *
5529  * Description:	Copy a pointer out from a user_addr_t in kernel space to
5530  *		user space, based on 32/64 bitness of the user space
5531  *
5532  * Parameters:	ua			User space address to copy to
5533  *		ptr			Address of kernel space user_addr_t
5534  *		ptr_size		4/8, based on 'ua' address space
5535  *
5536  * Returns:	0			Success
5537  *		EFAULT			Bad 'ua'
5538  *
5539  */
5540 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)5541 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
5542 {
5543 	int error;
5544 
5545 	if (ptr_size == 4) {
5546 		/* 64 bit value containing 32 bit address */
5547 		unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua);   /* SAFE */
5548 
5549 		error = copyout(&i, ptr, 4);
5550 	} else {
5551 		error = copyout(&ua, ptr, 8);
5552 	}
5553 	return error;
5554 }
5555 
5556 
5557 /*
5558  * exec_copyout_strings
5559  *
5560  * Copy out the strings segment to user space.  The strings segment is put
5561  * on a preinitialized stack frame.
5562  *
5563  * Parameters:	struct image_params *	the image parameter block
5564  *		int *			a pointer to the stack offset variable
5565  *
5566  * Returns:	0			Success
5567  *		!0			Faiure: errno
5568  *
5569  * Implicit returns:
5570  *		(*stackp)		The stack offset, modified
5571  *
5572  * Note:	The strings segment layout is backward, from the beginning
5573  *		of the top of the stack to consume the minimal amount of
5574  *		space possible; the returned stack pointer points to the
5575  *		end of the area consumed (stacks grow downward).
5576  *
5577  *		argc is an int; arg[i] are pointers; env[i] are pointers;
5578  *		the 0's are (void *)NULL's
5579  *
5580  * The stack frame layout is:
5581  *
5582  *      +-------------+ <- p->user_stack
5583  *      |     16b     |
5584  *      +-------------+
5585  *      | STRING AREA |
5586  *      |      :      |
5587  *      |      :      |
5588  *      |      :      |
5589  *      +- -- -- -- --+
5590  *      |  PATH AREA  |
5591  *      +-------------+
5592  *      |      0      |
5593  *      +-------------+
5594  *      |  applev[n]  |
5595  *      +-------------+
5596  *             :
5597  *             :
5598  *      +-------------+
5599  *      |  applev[1]  |
5600  *      +-------------+
5601  *      | exec_path / |
5602  *      |  applev[0]  |
5603  *      +-------------+
5604  *      |      0      |
5605  *      +-------------+
5606  *      |    env[n]   |
5607  *      +-------------+
5608  *             :
5609  *             :
5610  *      +-------------+
5611  *      |    env[0]   |
5612  *      +-------------+
5613  *      |      0      |
5614  *      +-------------+
5615  *      | arg[argc-1] |
5616  *      +-------------+
5617  *             :
5618  *             :
5619  *      +-------------+
5620  *      |    arg[0]   |
5621  *      +-------------+
5622  *      |     argc    |
5623  * sp-> +-------------+
5624  *
5625  * Although technically a part of the STRING AREA, we treat the PATH AREA as
5626  * a separate entity.  This allows us to align the beginning of the PATH AREA
5627  * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
5628  * which preceed it on the stack are properly aligned.
5629  */
5630 __attribute__((noinline))
5631 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)5632 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
5633 {
5634 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5635 	int     ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5636 	int     ptr_area_size;
5637 	void *ptr_buffer_start, *ptr_buffer;
5638 	size_t string_size;
5639 
5640 	user_addr_t     string_area;    /* *argv[], *env[] */
5641 	user_addr_t     ptr_area;       /* argv[], env[], applev[] */
5642 	user_addr_t argc_area;  /* argc */
5643 	user_addr_t     stack;
5644 	int error;
5645 
5646 	unsigned i;
5647 	struct copyout_desc {
5648 		char    *start_string;
5649 		int             count;
5650 #if CONFIG_DTRACE
5651 		user_addr_t     *dtrace_cookie;
5652 #endif
5653 		boolean_t       null_term;
5654 	} descriptors[] = {
5655 		{
5656 			.start_string = imgp->ip_startargv,
5657 			.count = imgp->ip_argc,
5658 #if CONFIG_DTRACE
5659 			.dtrace_cookie = &p->p_dtrace_argv,
5660 #endif
5661 			.null_term = TRUE
5662 		},
5663 		{
5664 			.start_string = imgp->ip_endargv,
5665 			.count = imgp->ip_envc,
5666 #if CONFIG_DTRACE
5667 			.dtrace_cookie = &p->p_dtrace_envp,
5668 #endif
5669 			.null_term = TRUE
5670 		},
5671 		{
5672 			.start_string = imgp->ip_strings,
5673 			.count = 1,
5674 #if CONFIG_DTRACE
5675 			.dtrace_cookie = NULL,
5676 #endif
5677 			.null_term = FALSE
5678 		},
5679 		{
5680 			.start_string = imgp->ip_endenvv,
5681 			.count = imgp->ip_applec - 1, /* exec_path handled above */
5682 #if CONFIG_DTRACE
5683 			.dtrace_cookie = NULL,
5684 #endif
5685 			.null_term = TRUE
5686 		}
5687 	};
5688 
5689 	stack = *stackp;
5690 
5691 	/*
5692 	 * All previous contributors to the string area
5693 	 * should have aligned their sub-area
5694 	 */
5695 	if (imgp->ip_strspace % ptr_size != 0) {
5696 		error = EINVAL;
5697 		goto bad;
5698 	}
5699 
5700 	/* Grow the stack down for the strings we've been building up */
5701 	string_size = imgp->ip_strendp - imgp->ip_strings;
5702 	stack -= string_size;
5703 	string_area = stack;
5704 
5705 	/*
5706 	 * Need room for one pointer for each string, plus
5707 	 * one for the NULLs terminating the argv, envv, and apple areas.
5708 	 */
5709 	ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5710 	stack -= ptr_area_size;
5711 	ptr_area = stack;
5712 
5713 	/* We'll construct all the pointer arrays in our string buffer,
5714 	 * which we already know is aligned properly, and ip_argspace
5715 	 * was used to verify we have enough space.
5716 	 */
5717 	ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5718 
5719 	/*
5720 	 * Need room for pointer-aligned argc slot.
5721 	 */
5722 	stack -= ptr_size;
5723 	argc_area = stack;
5724 
5725 	/*
5726 	 * Record the size of the arguments area so that sysctl_procargs()
5727 	 * can return the argument area without having to parse the arguments.
5728 	 */
5729 	proc_lock(p);
5730 	p->p_argc = imgp->ip_argc;
5731 	p->p_argslen = (int)(*stackp - string_area);
5732 	proc_unlock(p);
5733 
5734 	/* Return the initial stack address: the location of argc */
5735 	*stackp = stack;
5736 
5737 	/*
5738 	 * Copy out the entire strings area.
5739 	 */
5740 	error = copyout(imgp->ip_strings, string_area,
5741 	    string_size);
5742 	if (error) {
5743 		goto bad;
5744 	}
5745 
5746 	for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
5747 		char *cur_string = descriptors[i].start_string;
5748 		int j;
5749 
5750 #if CONFIG_DTRACE
5751 		if (descriptors[i].dtrace_cookie) {
5752 			proc_lock(p);
5753 			*descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
5754 			proc_unlock(p);
5755 		}
5756 #endif /* CONFIG_DTRACE */
5757 
5758 		/*
5759 		 * For each segment (argv, envv, applev), copy as many pointers as requested
5760 		 * to our pointer buffer.
5761 		 */
5762 		for (j = 0; j < descriptors[i].count; j++) {
5763 			user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
5764 
5765 			/* Copy out the pointer to the current string. Alignment has been verified  */
5766 			if (ptr_size == 8) {
5767 				*(uint64_t *)ptr_buffer = (uint64_t)cur_address;
5768 			} else {
5769 				*(uint32_t *)ptr_buffer = (uint32_t)cur_address;
5770 			}
5771 
5772 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5773 			cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
5774 		}
5775 
5776 		if (descriptors[i].null_term) {
5777 			if (ptr_size == 8) {
5778 				*(uint64_t *)ptr_buffer = 0ULL;
5779 			} else {
5780 				*(uint32_t *)ptr_buffer = 0;
5781 			}
5782 
5783 			ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5784 		}
5785 	}
5786 
5787 	/*
5788 	 * Copy out all our pointer arrays in bulk.
5789 	 */
5790 	error = copyout(ptr_buffer_start, ptr_area,
5791 	    ptr_area_size);
5792 	if (error) {
5793 		goto bad;
5794 	}
5795 
5796 	/* argc (int32, stored in a ptr_size area) */
5797 	error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
5798 	if (error) {
5799 		goto bad;
5800 	}
5801 
5802 bad:
5803 	return error;
5804 }
5805 
5806 
5807 /*
5808  * exec_extract_strings
5809  *
5810  * Copy arguments and environment from user space into work area; we may
5811  * have already copied some early arguments into the work area, and if
5812  * so, any arguments opied in are appended to those already there.
5813  * This function is the primary manipulator of ip_argspace, since
5814  * these are the arguments the client of execve(2) knows about. After
5815  * each argv[]/envv[] string is copied, we charge the string length
5816  * and argv[]/envv[] pointer slot to ip_argspace, so that we can
5817  * full preflight the arg list size.
5818  *
5819  * Parameters:	struct image_params *	the image parameter block
5820  *
5821  * Returns:	0			Success
5822  *		!0			Failure: errno
5823  *
5824  * Implicit returns;
5825  *		(imgp->ip_argc)		Count of arguments, updated
5826  *		(imgp->ip_envc)		Count of environment strings, updated
5827  *		(imgp->ip_argspace)	Count of remaining of NCARGS
5828  *		(imgp->ip_interp_buffer)	Interpreter and args (mutated in place)
5829  *
5830  *
5831  * Note:	The argument and environment vectors are user space pointers
5832  *		to arrays of user space pointers.
5833  */
5834 __attribute__((noinline))
5835 static int
exec_extract_strings(struct image_params * imgp)5836 exec_extract_strings(struct image_params *imgp)
5837 {
5838 	int error = 0;
5839 	int     ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
5840 	int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5841 	user_addr_t     argv = imgp->ip_user_argv;
5842 	user_addr_t     envv = imgp->ip_user_envv;
5843 
5844 	/*
5845 	 * Adjust space reserved for the path name by however much padding it
5846 	 * needs. Doing this here since we didn't know if this would be a 32-
5847 	 * or 64-bit process back in exec_save_path.
5848 	 */
5849 	while (imgp->ip_strspace % new_ptr_size != 0) {
5850 		*imgp->ip_strendp++ = '\0';
5851 		imgp->ip_strspace--;
5852 		/* imgp->ip_argspace--; not counted towards exec args total */
5853 	}
5854 
5855 	/*
5856 	 * From now on, we start attributing string space to ip_argspace
5857 	 */
5858 	imgp->ip_startargv = imgp->ip_strendp;
5859 	imgp->ip_argc = 0;
5860 
5861 	if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
5862 		user_addr_t     arg;
5863 		char *argstart, *ch;
5864 
5865 		/* First, the arguments in the "#!" string are tokenized and extracted. */
5866 		argstart = imgp->ip_interp_buffer;
5867 		while (argstart) {
5868 			ch = argstart;
5869 			while (*ch && !IS_WHITESPACE(*ch)) {
5870 				ch++;
5871 			}
5872 
5873 			if (*ch == '\0') {
5874 				/* last argument, no need to NUL-terminate */
5875 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5876 				argstart = NULL;
5877 			} else {
5878 				/* NUL-terminate */
5879 				*ch = '\0';
5880 				error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5881 
5882 				/*
5883 				 * Find the next string. We know spaces at the end of the string have already
5884 				 * been stripped.
5885 				 */
5886 				argstart = ch + 1;
5887 				while (IS_WHITESPACE(*argstart)) {
5888 					argstart++;
5889 				}
5890 			}
5891 
5892 			/* Error-check, regardless of whether this is the last interpreter arg or not */
5893 			if (error) {
5894 				goto bad;
5895 			}
5896 			if (imgp->ip_argspace < new_ptr_size) {
5897 				error = E2BIG;
5898 				goto bad;
5899 			}
5900 			imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5901 			imgp->ip_argc++;
5902 		}
5903 
5904 		if (argv != 0LL) {
5905 			/*
5906 			 * If we are running an interpreter, replace the av[0] that was
5907 			 * passed to execve() with the path name that was
5908 			 * passed to execve() for interpreters which do not use the PATH
5909 			 * to locate their script arguments.
5910 			 */
5911 			error = copyinptr(argv, &arg, ptr_size);
5912 			if (error) {
5913 				goto bad;
5914 			}
5915 			if (arg != 0LL) {
5916 				argv += ptr_size; /* consume without using */
5917 			}
5918 		}
5919 
5920 		if (imgp->ip_interp_sugid_fd != -1) {
5921 			char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
5922 			snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
5923 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
5924 		} else {
5925 			error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
5926 		}
5927 
5928 		if (error) {
5929 			goto bad;
5930 		}
5931 		if (imgp->ip_argspace < new_ptr_size) {
5932 			error = E2BIG;
5933 			goto bad;
5934 		}
5935 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5936 		imgp->ip_argc++;
5937 	}
5938 
5939 	while (argv != 0LL) {
5940 		user_addr_t     arg;
5941 
5942 		error = copyinptr(argv, &arg, ptr_size);
5943 		if (error) {
5944 			goto bad;
5945 		}
5946 
5947 		if (arg == 0LL) {
5948 			break;
5949 		}
5950 
5951 		argv += ptr_size;
5952 
5953 		/*
5954 		 * av[n...] = arg[n]
5955 		 */
5956 		error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
5957 		if (error) {
5958 			goto bad;
5959 		}
5960 		if (imgp->ip_argspace < new_ptr_size) {
5961 			error = E2BIG;
5962 			goto bad;
5963 		}
5964 		imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5965 		imgp->ip_argc++;
5966 	}
5967 
5968 	/* Save space for argv[] NULL terminator */
5969 	if (imgp->ip_argspace < new_ptr_size) {
5970 		error = E2BIG;
5971 		goto bad;
5972 	}
5973 	imgp->ip_argspace -= new_ptr_size;
5974 
5975 	/* Note where the args ends and env begins. */
5976 	imgp->ip_endargv = imgp->ip_strendp;
5977 	imgp->ip_envc = 0;
5978 
5979 	/* Now, get the environment */
5980 	while (envv != 0LL) {
5981 		user_addr_t     env;
5982 
5983 		error = copyinptr(envv, &env, ptr_size);
5984 		if (error) {
5985 			goto bad;
5986 		}
5987 
5988 		envv += ptr_size;
5989 		if (env == 0LL) {
5990 			break;
5991 		}
5992 		/*
5993 		 * av[n...] = env[n]
5994 		 */
5995 		error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
5996 		if (error) {
5997 			goto bad;
5998 		}
5999 		if (imgp->ip_argspace < new_ptr_size) {
6000 			error = E2BIG;
6001 			goto bad;
6002 		}
6003 		imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
6004 		imgp->ip_envc++;
6005 	}
6006 
6007 	/* Save space for envv[] NULL terminator */
6008 	if (imgp->ip_argspace < new_ptr_size) {
6009 		error = E2BIG;
6010 		goto bad;
6011 	}
6012 	imgp->ip_argspace -= new_ptr_size;
6013 
6014 	/* Align the tail of the combined argv+envv area */
6015 	while (imgp->ip_strspace % new_ptr_size != 0) {
6016 		if (imgp->ip_argspace < 1) {
6017 			error = E2BIG;
6018 			goto bad;
6019 		}
6020 		*imgp->ip_strendp++ = '\0';
6021 		imgp->ip_strspace--;
6022 		imgp->ip_argspace--;
6023 	}
6024 
6025 	/* Note where the envv ends and applev begins. */
6026 	imgp->ip_endenvv = imgp->ip_strendp;
6027 
6028 	/*
6029 	 * From now on, we are no longer charging argument
6030 	 * space to ip_argspace.
6031 	 */
6032 
6033 bad:
6034 	return error;
6035 }
6036 
6037 /*
6038  * Libc has an 8-element array set up for stack guard values.  It only fills
6039  * in one of those entries, and both gcc and llvm seem to use only a single
6040  * 8-byte guard.  Until somebody needs more than an 8-byte guard value, don't
6041  * do the work to construct them.
6042  */
6043 #define GUARD_VALUES 1
6044 #define GUARD_KEY "stack_guard="
6045 
6046 /*
6047  * System malloc needs some entropy when it is initialized.
6048  */
6049 #define ENTROPY_VALUES 2
6050 #define ENTROPY_KEY "malloc_entropy="
6051 
6052 /*
6053  * libplatform needs a random pointer-obfuscation value when it is initialized.
6054  */
6055 #define PTR_MUNGE_VALUES 1
6056 #define PTR_MUNGE_KEY "ptr_munge="
6057 
6058 /*
6059  * System malloc engages nanozone for UIAPP.
6060  */
6061 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
6062 
6063 /*
6064  * Used to pass experiment flags up to libmalloc.
6065  */
6066 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
6067 
6068 /*
6069  * Passes information about hardened runtime entitlements to libsystem/libmalloc
6070  */
6071 #define HARDENED_RUNTIME_KEY "HardenedRuntime="
6072 
6073 #define PFZ_KEY "pfz="
6074 extern user32_addr_t commpage_text32_location;
6075 extern user64_addr_t commpage_text64_location;
6076 
6077 extern uuid_string_t bootsessionuuid_string;
6078 static TUNABLE(uint32_t, exe_boothash_salt, "exe_boothash_salt", 0);
6079 
6080 __startup_func
6081 static void
exe_boothash_salt_generate(void)6082 exe_boothash_salt_generate(void)
6083 {
6084 	if (!PE_parse_boot_argn("exe_boothash_salt", NULL, 0)) {
6085 		read_random(&exe_boothash_salt, sizeof(exe_boothash_salt));
6086 	}
6087 }
6088 STARTUP(EARLY_BOOT, STARTUP_RANK_MIDDLE, exe_boothash_salt_generate);
6089 
6090 
6091 #define MAIN_STACK_VALUES 4
6092 #define MAIN_STACK_KEY "main_stack="
6093 
6094 #define FSID_KEY "executable_file="
6095 #define DYLD_FSID_KEY "dyld_file="
6096 #define CDHASH_KEY "executable_cdhash="
6097 #define DYLD_FLAGS_KEY "dyld_flags="
6098 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
6099 #define APP_BOOT_SESSION_KEY "executable_boothash="
6100 #if __has_feature(ptrauth_calls)
6101 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
6102 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
6103 #endif /* __has_feature(ptrauth_calls) */
6104 #define MAIN_TH_PORT_KEY "th_port="
6105 
6106 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
6107 
6108 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
6109 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
6110 
6111 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6112 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
6113 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6114 
6115 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)6116 exec_add_entropy_key(struct image_params *imgp,
6117     const char *key,
6118     int values,
6119     boolean_t embedNUL)
6120 {
6121 	const int limit = 8;
6122 	uint64_t entropy[limit];
6123 	char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
6124 	if (values > limit) {
6125 		values = limit;
6126 	}
6127 
6128 	read_random(entropy, sizeof(entropy[0]) * values);
6129 
6130 	if (embedNUL) {
6131 		entropy[0] &= ~(0xffull << 8);
6132 	}
6133 
6134 	int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
6135 	size_t remaining = sizeof(str) - len;
6136 	for (int i = 1; i < values && remaining > 0; ++i) {
6137 		size_t start = sizeof(str) - remaining;
6138 		len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
6139 		remaining -= len;
6140 	}
6141 
6142 	return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
6143 }
6144 
6145 /*
6146  * Build up the contents of the apple[] string vector
6147  */
6148 #if (DEVELOPMENT || DEBUG)
6149 extern uint64_t dyld_flags;
6150 #endif
6151 
6152 #if __has_feature(ptrauth_calls)
6153 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)6154 is_arm64e_running_as_arm64(const struct image_params *imgp)
6155 {
6156 	return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
6157 	       (imgp->ip_flags & IMGPF_NOJOP);
6158 }
6159 #endif /* __has_feature(ptrauth_calls) */
6160 
6161 _Atomic uint64_t libmalloc_experiment_factors = 0;
6162 
6163 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result)6164 exec_add_apple_strings(struct image_params *imgp,
6165     const load_result_t *load_result)
6166 {
6167 	int error;
6168 	int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6169 	thread_t new_thread;
6170 	ipc_port_t sright;
6171 	uint64_t local_experiment_factors = 0;
6172 
6173 	/* exec_save_path stored the first string */
6174 	imgp->ip_applec = 1;
6175 
6176 	/* adding the pfz string */
6177 	{
6178 		char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
6179 
6180 		if (img_ptr_size == 8) {
6181 			__assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
6182 			assert(ret < sizeof(pfz_string));
6183 		} else {
6184 			snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
6185 		}
6186 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
6187 		if (error) {
6188 			printf("Failed to add the pfz string with error %d\n", error);
6189 			goto bad;
6190 		}
6191 		imgp->ip_applec++;
6192 	}
6193 
6194 	/* adding the NANO_ENGAGE_KEY key */
6195 	if (imgp->ip_px_sa) {
6196 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6197 		int proc_flags = psa->psa_flags;
6198 
6199 		if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
6200 			const char *nano_string = NANO_ENGAGE_KEY;
6201 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
6202 			if (error) {
6203 				goto bad;
6204 			}
6205 			imgp->ip_applec++;
6206 		}
6207 	}
6208 
6209 	/*
6210 	 * Supply libc with a collection of random values to use when
6211 	 * implementing -fstack-protector.
6212 	 *
6213 	 * (The first random string always contains an embedded NUL so that
6214 	 * __stack_chk_guard also protects against C string vulnerabilities)
6215 	 */
6216 	error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
6217 	if (error) {
6218 		goto bad;
6219 	}
6220 	imgp->ip_applec++;
6221 
6222 	/*
6223 	 * Supply libc with entropy for system malloc.
6224 	 */
6225 	error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
6226 	if (error) {
6227 		goto bad;
6228 	}
6229 	imgp->ip_applec++;
6230 
6231 	/*
6232 	 * Supply libpthread & libplatform with a random value to use for pointer
6233 	 * obfuscation.
6234 	 */
6235 	error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
6236 	if (error) {
6237 		goto bad;
6238 	}
6239 	imgp->ip_applec++;
6240 
6241 	/*
6242 	 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
6243 	 * stack if it was allocated by the kernel.
6244 	 *
6245 	 * The guard page is not included in this stack size as libpthread
6246 	 * expects to add it back in after receiving this value.
6247 	 */
6248 	if (load_result->unixproc) {
6249 		char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
6250 		snprintf(stack_string, sizeof(stack_string),
6251 		    MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
6252 		    (uint64_t)load_result->user_stack,
6253 		    (uint64_t)load_result->user_stack_size,
6254 		    (uint64_t)load_result->user_stack_alloc,
6255 		    (uint64_t)load_result->user_stack_alloc_size);
6256 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
6257 		if (error) {
6258 			goto bad;
6259 		}
6260 		imgp->ip_applec++;
6261 	}
6262 
6263 	if (imgp->ip_vattr) {
6264 		uint64_t fsid    = vnode_get_va_fsid(imgp->ip_vattr);
6265 		uint64_t fsobjid = imgp->ip_vattr->va_fileid;
6266 
6267 		char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6268 		snprintf(fsid_string, sizeof(fsid_string),
6269 		    FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
6270 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6271 		if (error) {
6272 			goto bad;
6273 		}
6274 		imgp->ip_applec++;
6275 	}
6276 
6277 	if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
6278 		char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6279 		snprintf(fsid_string, sizeof(fsid_string),
6280 		    DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
6281 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6282 		if (error) {
6283 			goto bad;
6284 		}
6285 		imgp->ip_applec++;
6286 	}
6287 
6288 	uint8_t cdhash[SHA1_RESULTLEN];
6289 	int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash);
6290 	if (cdhash_errror == 0) {
6291 		char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
6292 		strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
6293 		char *p = hash_string + sizeof(CDHASH_KEY) - 1;
6294 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6295 			snprintf(p, 3, "%02x", (int) cdhash[i]);
6296 			p += 2;
6297 		}
6298 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
6299 		if (error) {
6300 			goto bad;
6301 		}
6302 		imgp->ip_applec++;
6303 
6304 		/* hash together cd-hash and boot-session-uuid */
6305 		uint8_t sha_digest[SHA256_DIGEST_LENGTH];
6306 		SHA256_CTX sha_ctx;
6307 		SHA256_Init(&sha_ctx);
6308 		SHA256_Update(&sha_ctx, &exe_boothash_salt, sizeof(exe_boothash_salt));
6309 		SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
6310 		SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
6311 		SHA256_Final(sha_digest, &sha_ctx);
6312 		char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
6313 		strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
6314 		char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
6315 		for (int i = 0; i < SHA1_RESULTLEN; i++) {
6316 			snprintf(s, 3, "%02x", (int) sha_digest[i]);
6317 			s += 2;
6318 		}
6319 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
6320 		if (error) {
6321 			goto bad;
6322 		}
6323 		imgp->ip_applec++;
6324 	}
6325 #if (DEVELOPMENT || DEBUG)
6326 	if (dyld_flags) {
6327 		char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
6328 		snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
6329 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
6330 		if (error) {
6331 			goto bad;
6332 		}
6333 		imgp->ip_applec++;
6334 	}
6335 #endif
6336 	if (imgp->ip_subsystem_root_path) {
6337 		size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
6338 		char subsystem_root_path_string[buffer_len];
6339 		int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
6340 
6341 		if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
6342 			error = ENAMETOOLONG;
6343 			goto bad;
6344 		}
6345 
6346 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
6347 		if (error) {
6348 			goto bad;
6349 		}
6350 
6351 		imgp->ip_applec++;
6352 	}
6353 #if __has_feature(ptrauth_calls)
6354 	if (is_arm64e_running_as_arm64(imgp)) {
6355 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
6356 		if (error) {
6357 			goto bad;
6358 		}
6359 
6360 		imgp->ip_applec++;
6361 	}
6362 #endif /* __has_feature(ptrauth_calls) */
6363 
6364 
6365 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
6366 	{
6367 		char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
6368 		strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
6369 		bool allowAll = bootarg_arm64e_preview_abi;
6370 		strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
6371 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
6372 		if (error) {
6373 			goto bad;
6374 		}
6375 
6376 		imgp->ip_applec++;
6377 	}
6378 #endif
6379 	/*
6380 	 * Add main thread mach port name
6381 	 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
6382 	 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
6383 	 * against libpthread.
6384 	 */
6385 	if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
6386 		thread_reference(new_thread);
6387 		sright = convert_thread_to_port_pinned(new_thread);
6388 		task_t new_task = get_threadtask(new_thread);
6389 		mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
6390 		char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
6391 		snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
6392 
6393 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
6394 		if (error) {
6395 			goto bad;
6396 		}
6397 		imgp->ip_applec++;
6398 	}
6399 
6400 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6401 	if (imgp->ip_px_sa != NULL) {
6402 		struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6403 		if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
6404 			const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
6405 			error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
6406 			if (error) {
6407 				goto bad;
6408 			}
6409 			imgp->ip_applec++;
6410 		}
6411 	}
6412 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6413 
6414 	/* adding the libmalloc experiment string */
6415 	local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
6416 	if (__improbable(local_experiment_factors != 0)) {
6417 		char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
6418 
6419 		snprintf(
6420 			libmalloc_experiment_factors_string,
6421 			sizeof(libmalloc_experiment_factors_string),
6422 			LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
6423 			local_experiment_factors);
6424 		error = exec_add_user_string(
6425 			imgp,
6426 			CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
6427 			UIO_SYSSPACE,
6428 			FALSE);
6429 		if (error) {
6430 			printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
6431 			goto bad;
6432 		}
6433 		imgp->ip_applec++;
6434 	}
6435 
6436 
6437 	/* tell dyld that it can leverage hardware for its read-only/read-write trusted path */
6438 	if (imgp->ip_flags & IMGPF_HW_TPRO) {
6439 		const char *dyld_hw_tpro = "dyld_hw_tpro=1";
6440 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_hw_tpro), UIO_SYSSPACE, FALSE);
6441 		if (error) {
6442 			printf("Failed to add dyld hw tpro setting with error %d\n", error);
6443 			goto bad;
6444 		}
6445 
6446 		imgp->ip_applec++;
6447 
6448 	}
6449 
6450 	if (load_result->hardened_runtime_binary) {
6451 		const size_t HR_STRING_SIZE = sizeof(HARDENED_RUNTIME_KEY) + HR_FLAGS_NUM_NIBBLES + 2 + 1;
6452 		char hardened_runtime[HR_STRING_SIZE];
6453 		snprintf(hardened_runtime, HR_STRING_SIZE, HARDENED_RUNTIME_KEY"0x%x", load_result->hardened_runtime_binary);
6454 		error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hardened_runtime), UIO_SYSSPACE, FALSE);
6455 		if (error) {
6456 			printf("Failed to add hardened runtime flag with error %d\n", error);
6457 			goto bad;
6458 		}
6459 		imgp->ip_applec++;
6460 	}
6461 	/* Align the tail of the combined applev area */
6462 	while (imgp->ip_strspace % img_ptr_size != 0) {
6463 		*imgp->ip_strendp++ = '\0';
6464 		imgp->ip_strspace--;
6465 	}
6466 
6467 bad:
6468 	return error;
6469 }
6470 
6471 /*
6472  * exec_check_permissions
6473  *
6474  * Description:	Verify that the file that is being attempted to be executed
6475  *		is in fact allowed to be executed based on it POSIX file
6476  *		permissions and other access control criteria
6477  *
6478  * Parameters:	struct image_params *	the image parameter block
6479  *
6480  * Returns:	0			Success
6481  *		EACCES			Permission denied
6482  *		ENOEXEC			Executable file format error
6483  *		ETXTBSY			Text file busy [misuse of error code]
6484  *	vnode_getattr:???
6485  *	vnode_authorize:???
6486  */
6487 static int
exec_check_permissions(struct image_params * imgp)6488 exec_check_permissions(struct image_params *imgp)
6489 {
6490 	struct vnode *vp = imgp->ip_vp;
6491 	struct vnode_attr *vap = imgp->ip_vattr;
6492 	proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6493 	int error;
6494 	kauth_action_t action;
6495 
6496 	/* Only allow execution of regular files */
6497 	if (!vnode_isreg(vp)) {
6498 		return EACCES;
6499 	}
6500 
6501 	/* Get the file attributes that we will be using here and elsewhere */
6502 	VATTR_INIT(vap);
6503 	VATTR_WANTED(vap, va_uid);
6504 	VATTR_WANTED(vap, va_gid);
6505 	VATTR_WANTED(vap, va_mode);
6506 	VATTR_WANTED(vap, va_fsid);
6507 	VATTR_WANTED(vap, va_fsid64);
6508 	VATTR_WANTED(vap, va_fileid);
6509 	VATTR_WANTED(vap, va_data_size);
6510 	if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
6511 		return error;
6512 	}
6513 
6514 	/*
6515 	 * Ensure that at least one execute bit is on - otherwise root
6516 	 * will always succeed, and we don't want to happen unless the
6517 	 * file really is executable.
6518 	 */
6519 	if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
6520 		return EACCES;
6521 	}
6522 
6523 	/* Disallow zero length files */
6524 	if (vap->va_data_size == 0) {
6525 		return ENOEXEC;
6526 	}
6527 
6528 	imgp->ip_arch_offset = (user_size_t)0;
6529 #if __LP64__
6530 	imgp->ip_arch_size = vap->va_data_size;
6531 #else
6532 	if (vap->va_data_size > UINT32_MAX) {
6533 		return ENOEXEC;
6534 	}
6535 	imgp->ip_arch_size = (user_size_t)vap->va_data_size;
6536 #endif
6537 
6538 	/* Disable setuid-ness for traced programs or if MNT_NOSUID */
6539 	if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
6540 		vap->va_mode &= ~(VSUID | VSGID);
6541 	}
6542 
6543 	/*
6544 	 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
6545 	 * flags for setuid/setgid binaries.
6546 	 */
6547 	if (vap->va_mode & (VSUID | VSGID)) {
6548 		imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
6549 	}
6550 
6551 #if CONFIG_MACF
6552 	error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
6553 	if (error) {
6554 		return error;
6555 	}
6556 #endif
6557 
6558 	/* Check for execute permission */
6559 	action = KAUTH_VNODE_EXECUTE;
6560 	/* Traced images must also be readable */
6561 	if (p->p_lflag & P_LTRACED) {
6562 		action |= KAUTH_VNODE_READ_DATA;
6563 	}
6564 	if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
6565 		return error;
6566 	}
6567 
6568 #if 0
6569 	/* Don't let it run if anyone had it open for writing */
6570 	vnode_lock(vp);
6571 	if (vp->v_writecount) {
6572 		panic("going to return ETXTBSY %x", vp);
6573 		vnode_unlock(vp);
6574 		return ETXTBSY;
6575 	}
6576 	vnode_unlock(vp);
6577 #endif
6578 
6579 	/* XXX May want to indicate to underlying FS that vnode is open */
6580 
6581 	return error;
6582 }
6583 
6584 
6585 /*
6586  * exec_handle_sugid
6587  *
6588  * Initially clear the P_SUGID in the process flags; if an SUGID process is
6589  * exec'ing a non-SUGID image, then  this is the point of no return.
6590  *
6591  * If the image being activated is SUGID, then replace the credential with a
6592  * copy, disable tracing (unless the tracing process is root), reset the
6593  * mach task port to revoke it, set the P_SUGID bit,
6594  *
6595  * If the saved user and group ID will be changing, then make sure it happens
6596  * to a new credential, rather than a shared one.
6597  *
6598  * Set the security token (this is probably obsolete, given that the token
6599  * should not technically be separate from the credential itself).
6600  *
6601  * Parameters:	struct image_params *	the image parameter block
6602  *
6603  * Returns:	void			No failure indication
6604  *
6605  * Implicit returns:
6606  *		<process credential>	Potentially modified/replaced
6607  *		<task port>		Potentially revoked
6608  *		<process flags>		P_SUGID bit potentially modified
6609  *		<security token>	Potentially modified
6610  */
6611 __attribute__((noinline))
6612 static int
exec_handle_sugid(struct image_params * imgp)6613 exec_handle_sugid(struct image_params *imgp)
6614 {
6615 	proc_t                  p = vfs_context_proc(imgp->ip_vfs_context);
6616 	kauth_cred_t            cred = vfs_context_ucred(imgp->ip_vfs_context);
6617 	int                     i;
6618 	int                     leave_sugid_clear = 0;
6619 	int                     mac_reset_ipc = 0;
6620 	int                     error = 0;
6621 #if CONFIG_MACF
6622 	int                     mac_transition, disjoint_cred = 0;
6623 	int             label_update_return = 0;
6624 
6625 	/*
6626 	 * Determine whether a call to update the MAC label will result in the
6627 	 * credential changing.
6628 	 *
6629 	 * Note:	MAC policies which do not actually end up modifying
6630 	 *		the label subsequently are strongly encouraged to
6631 	 *		return 0 for this check, since a non-zero answer will
6632 	 *		slow down the exec fast path for normal binaries.
6633 	 */
6634 	mac_transition = mac_cred_check_label_update_execve(
6635 		imgp->ip_vfs_context,
6636 		imgp->ip_vp,
6637 		imgp->ip_arch_offset,
6638 		imgp->ip_scriptvp,
6639 		imgp->ip_scriptlabelp,
6640 		imgp->ip_execlabelp,
6641 		p,
6642 		&imgp->ip_px_smpx);
6643 #endif
6644 
6645 	OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
6646 
6647 	/*
6648 	 * Order of the following is important; group checks must go last,
6649 	 * as we use the success of the 'ismember' check combined with the
6650 	 * failure of the explicit match to indicate that we will be setting
6651 	 * the egid of the process even though the new process did not
6652 	 * require VSUID/VSGID bits in order for it to set the new group as
6653 	 * its egid.
6654 	 *
6655 	 * Note:	Technically, by this we are implying a call to
6656 	 *		setegid() in the new process, rather than implying
6657 	 *		it used its VSGID bit to set the effective group,
6658 	 *		even though there is no code in that process to make
6659 	 *		such a call.
6660 	 */
6661 	if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
6662 	    kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
6663 	    ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
6664 	    ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
6665 	    (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
6666 #if CONFIG_MACF
6667 /* label for MAC transition and neither VSUID nor VSGID */
6668 handle_mac_transition:
6669 #endif
6670 
6671 #if CONFIG_SETUID
6672 		/*
6673 		 * Replace the credential with a copy of itself if euid or
6674 		 * egid change.
6675 		 *
6676 		 * Note:	setuid binaries will automatically opt out of
6677 		 *		group resolver participation as a side effect
6678 		 *		of this operation.  This is an intentional
6679 		 *		part of the security model, which requires a
6680 		 *		participating credential be established by
6681 		 *		escalating privilege, setting up all other
6682 		 *		aspects of the credential including whether
6683 		 *		or not to participate in external group
6684 		 *		membership resolution, then dropping their
6685 		 *		effective privilege to that of the desired
6686 		 *		final credential state.
6687 		 *
6688 		 * Modifications to p_ucred must be guarded using the
6689 		 * proc's ucred lock. This prevents others from accessing
6690 		 * a garbage credential.
6691 		 */
6692 
6693 		if (imgp->ip_origvattr->va_mode & VSUID) {
6694 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6695 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6696 				return kauth_cred_model_setresuid(model,
6697 				KAUTH_UID_NONE,
6698 				imgp->ip_origvattr->va_uid,
6699 				imgp->ip_origvattr->va_uid,
6700 				KAUTH_UID_NONE);
6701 			});
6702 		}
6703 
6704 		if (imgp->ip_origvattr->va_mode & VSGID) {
6705 			kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6706 			    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6707 				return kauth_cred_model_setresgid(model,
6708 				KAUTH_GID_NONE,
6709 				imgp->ip_origvattr->va_gid,
6710 				imgp->ip_origvattr->va_gid);
6711 			});
6712 		}
6713 #endif /* CONFIG_SETUID */
6714 
6715 #if CONFIG_MACF
6716 		/*
6717 		 * If a policy has indicated that it will transition the label,
6718 		 * before making the call into the MAC policies, get a new
6719 		 * duplicate credential, so they can modify it without
6720 		 * modifying any others sharing it.
6721 		 */
6722 		if (mac_transition) {
6723 			/*
6724 			 * This hook may generate upcalls that require
6725 			 * importance donation from the kernel.
6726 			 * (23925818)
6727 			 */
6728 			thread_t thread = current_thread();
6729 			thread_enable_send_importance(thread, TRUE);
6730 			kauth_proc_label_update_execve(p,
6731 			    imgp->ip_vfs_context,
6732 			    imgp->ip_vp,
6733 			    imgp->ip_arch_offset,
6734 			    imgp->ip_scriptvp,
6735 			    imgp->ip_scriptlabelp,
6736 			    imgp->ip_execlabelp,
6737 			    &imgp->ip_csflags,
6738 			    &imgp->ip_px_smpx,
6739 			    &disjoint_cred,                     /* will be non zero if disjoint */
6740 			    &label_update_return);
6741 			thread_enable_send_importance(thread, FALSE);
6742 
6743 			if (disjoint_cred) {
6744 				/*
6745 				 * If updating the MAC label resulted in a
6746 				 * disjoint credential, flag that we need to
6747 				 * set the P_SUGID bit.  This protects
6748 				 * against debuggers being attached by an
6749 				 * insufficiently privileged process onto the
6750 				 * result of a transition to a more privileged
6751 				 * credential.
6752 				 */
6753 				leave_sugid_clear = 0;
6754 			}
6755 
6756 			imgp->ip_mac_return = label_update_return;
6757 		}
6758 
6759 		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);
6760 
6761 #endif  /* CONFIG_MACF */
6762 
6763 		/*
6764 		 * If 'leave_sugid_clear' is non-zero, then we passed the
6765 		 * VSUID and MACF checks, and successfully determined that
6766 		 * the previous cred was a member of the VSGID group, but
6767 		 * that it was not the default at the time of the execve,
6768 		 * and that the post-labelling credential was not disjoint.
6769 		 * So we don't set the P_SUGID or reset mach ports and fds
6770 		 * on the basis of simply running this code.
6771 		 */
6772 		if (mac_reset_ipc || !leave_sugid_clear) {
6773 			/*
6774 			 * Have mach reset the task and thread ports.
6775 			 * We don't want anyone who had the ports before
6776 			 * a setuid exec to be able to access/control the
6777 			 * task/thread after.
6778 			 */
6779 			ipc_task_reset((imgp->ip_new_thread != NULL) ?
6780 			    get_threadtask(imgp->ip_new_thread) : proc_task(p));
6781 			ipc_thread_reset((imgp->ip_new_thread != NULL) ?
6782 			    imgp->ip_new_thread : current_thread());
6783 		}
6784 
6785 		if (!leave_sugid_clear) {
6786 			/*
6787 			 * Flag the process as setuid.
6788 			 */
6789 			OSBitOrAtomic(P_SUGID, &p->p_flag);
6790 
6791 			/*
6792 			 * Radar 2261856; setuid security hole fix
6793 			 * XXX For setuid processes, attempt to ensure that
6794 			 * stdin, stdout, and stderr are already allocated.
6795 			 * We do not want userland to accidentally allocate
6796 			 * descriptors in this range which has implied meaning
6797 			 * to libc.
6798 			 */
6799 			for (i = 0; i < 3; i++) {
6800 				if (fp_get_noref_locked(p, i) != NULL) {
6801 					continue;
6802 				}
6803 
6804 				/*
6805 				 * Do the kernel equivalent of
6806 				 *
6807 				 *      if i == 0
6808 				 *              (void) open("/dev/null", O_RDONLY);
6809 				 *      else
6810 				 *              (void) open("/dev/null", O_WRONLY);
6811 				 */
6812 
6813 				struct fileproc *fp;
6814 				int indx;
6815 				int flag;
6816 				struct nameidata *ndp = NULL;
6817 
6818 				if (i == 0) {
6819 					flag = FREAD;
6820 				} else {
6821 					flag = FWRITE;
6822 				}
6823 
6824 				if ((error = falloc_exec(p, imgp->ip_vfs_context,
6825 				    &fp, &indx)) != 0) {
6826 					continue;
6827 				}
6828 
6829 				ndp = kalloc_type(struct nameidata,
6830 				    Z_WAITOK | Z_ZERO | Z_NOFAIL);
6831 
6832 				NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
6833 				    CAST_USER_ADDR_T("/dev/null"),
6834 				    imgp->ip_vfs_context);
6835 
6836 				if ((error = vn_open(ndp, flag, 0)) != 0) {
6837 					fp_free(p, indx, fp);
6838 					kfree_type(struct nameidata, ndp);
6839 					break;
6840 				}
6841 
6842 				struct fileglob *fg = fp->fp_glob;
6843 
6844 				fg->fg_flag = flag;
6845 				fg->fg_ops = &vnops;
6846 				fp_set_data(fp, ndp->ni_vp);
6847 
6848 				vnode_put(ndp->ni_vp);
6849 
6850 				proc_fdlock(p);
6851 				procfdtbl_releasefd(p, indx, NULL);
6852 				fp_drop(p, indx, fp, 1);
6853 				proc_fdunlock(p);
6854 
6855 				kfree_type(struct nameidata, ndp);
6856 			}
6857 		}
6858 	}
6859 #if CONFIG_MACF
6860 	else {
6861 		/*
6862 		 * We are here because we were told that the MAC label will
6863 		 * be transitioned, and the binary is not VSUID or VSGID; to
6864 		 * deal with this case, we could either duplicate a lot of
6865 		 * code, or we can indicate we want to default the P_SUGID
6866 		 * bit clear and jump back up.
6867 		 */
6868 		if (mac_transition) {
6869 			leave_sugid_clear = 1;
6870 			goto handle_mac_transition;
6871 		}
6872 	}
6873 
6874 #endif  /* CONFIG_MACF */
6875 
6876 	/* Update the process' identity version and set the security token */
6877 	proc_setpidversion(p, OSIncrementAtomic(&nextpidversion));
6878 	task_set_uniqueid(proc_task(p));
6879 
6880 	/*
6881 	 * Implement the semantic where the effective user and group become
6882 	 * the saved user and group in exec'ed programs.
6883 	 */
6884 	kauth_cred_proc_update(p, PROC_SETTOKEN_ALWAYS,
6885 	    ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6886 		posix_cred_t pcred = posix_cred_get(model);
6887 
6888 		if (pcred->cr_svuid == pcred->cr_uid &&
6889 		pcred->cr_svgid == pcred->cr_gid) {
6890 		        return false;
6891 		}
6892 
6893 		pcred->cr_svuid = pcred->cr_uid;
6894 		pcred->cr_svgid = pcred->cr_gid;
6895 		return true;
6896 	});
6897 
6898 	return error;
6899 }
6900 
6901 
6902 /*
6903  * create_unix_stack
6904  *
6905  * Description:	Set the user stack address for the process to the provided
6906  *		address.  If a custom stack was not set as a result of the
6907  *		load process (i.e. as specified by the image file for the
6908  *		executable), then allocate the stack in the provided map and
6909  *		set up appropriate guard pages for enforcing administrative
6910  *		limits on stack growth, if they end up being needed.
6911  *
6912  * Parameters:	p			Process to set stack on
6913  *		load_result		Information from mach-o load commands
6914  *		map			Address map in which to allocate the new stack
6915  *
6916  * Returns:	KERN_SUCCESS		Stack successfully created
6917  *		!KERN_SUCCESS		Mach failure code
6918  */
6919 __attribute__((noinline))
6920 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)6921 create_unix_stack(vm_map_t map, load_result_t* load_result,
6922     proc_t p)
6923 {
6924 	mach_vm_size_t          size, prot_size;
6925 	mach_vm_offset_t        addr, prot_addr;
6926 	kern_return_t           kr;
6927 
6928 	mach_vm_address_t       user_stack = load_result->user_stack;
6929 
6930 	proc_lock(p);
6931 	p->user_stack = (uintptr_t)user_stack;
6932 	if (load_result->custom_stack) {
6933 		p->p_lflag |= P_LCUSTOM_STACK;
6934 	}
6935 	proc_unlock(p);
6936 	if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
6937 		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);
6938 	}
6939 
6940 	if (load_result->user_stack_alloc_size > 0) {
6941 		/*
6942 		 * Allocate enough space for the maximum stack size we
6943 		 * will ever authorize and an extra page to act as
6944 		 * a guard page for stack overflows. For default stacks,
6945 		 * vm_initial_limit_stack takes care of the extra guard page.
6946 		 * Otherwise we must allocate it ourselves.
6947 		 */
6948 		if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
6949 			return KERN_INVALID_ARGUMENT;
6950 		}
6951 		addr = vm_map_trunc_page(load_result->user_stack - size,
6952 		    vm_map_page_mask(map));
6953 		kr = mach_vm_allocate_kernel(map, &addr, size,
6954 		    VM_FLAGS_FIXED, VM_MEMORY_STACK);
6955 		if (kr != KERN_SUCCESS) {
6956 			// Can't allocate at default location, try anywhere
6957 			addr = 0;
6958 			kr = mach_vm_allocate_kernel(map, &addr, size,
6959 			    VM_FLAGS_ANYWHERE, VM_MEMORY_STACK);
6960 			if (kr != KERN_SUCCESS) {
6961 				return kr;
6962 			}
6963 
6964 			user_stack = addr + size;
6965 			load_result->user_stack = (user_addr_t)user_stack;
6966 
6967 			proc_lock(p);
6968 			p->user_stack = (uintptr_t)user_stack;
6969 			proc_unlock(p);
6970 		}
6971 
6972 		load_result->user_stack_alloc = (user_addr_t)addr;
6973 
6974 		/*
6975 		 * And prevent access to what's above the current stack
6976 		 * size limit for this process.
6977 		 */
6978 		if (load_result->user_stack_size == 0) {
6979 			load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
6980 			prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
6981 		} else {
6982 			prot_size = PAGE_SIZE;
6983 		}
6984 
6985 		prot_addr = addr;
6986 		kr = mach_vm_protect(map,
6987 		    prot_addr,
6988 		    prot_size,
6989 		    FALSE,
6990 		    VM_PROT_NONE);
6991 		if (kr != KERN_SUCCESS) {
6992 			(void)mach_vm_deallocate(map, addr, size);
6993 			return kr;
6994 		}
6995 	}
6996 
6997 	return KERN_SUCCESS;
6998 }
6999 
7000 #include <sys/reboot.h>
7001 
7002 /*
7003  * load_init_program_at_path
7004  *
7005  * Description:	Load the "init" program; in most cases, this will be "launchd"
7006  *
7007  * Parameters:	p			Process to call execve() to create
7008  *					the "init" program
7009  *		scratch_addr		Page in p, scratch space
7010  *		path			NULL terminated path
7011  *
7012  * Returns:	KERN_SUCCESS		Success
7013  *		!KERN_SUCCESS           See execve/mac_execve for error codes
7014  *
7015  * Notes:	The process that is passed in is the first manufactured
7016  *		process on the system, and gets here via bsd_ast() firing
7017  *		for the first time.  This is done to ensure that bsd_init()
7018  *		has run to completion.
7019  *
7020  *		The address map of the first manufactured process matches the
7021  *		word width of the kernel. Once the self-exec completes, the
7022  *		initproc might be different.
7023  */
7024 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)7025 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
7026 {
7027 	int retval[2];
7028 	int error;
7029 	struct execve_args init_exec_args;
7030 	user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
7031 
7032 	/*
7033 	 * Validate inputs and pre-conditions
7034 	 */
7035 	assert(p);
7036 	assert(scratch_addr);
7037 	assert(path);
7038 
7039 	/*
7040 	 * Copy out program name.
7041 	 */
7042 	size_t path_length = strlen(path) + 1;
7043 	argv0 = scratch_addr;
7044 	error = copyout(path, argv0, path_length);
7045 	if (error) {
7046 		return error;
7047 	}
7048 
7049 	scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
7050 
7051 	/*
7052 	 * Put out first (and only) argument, similarly.
7053 	 * Assumes everything fits in a page as allocated above.
7054 	 */
7055 	if (boothowto & RB_SINGLE) {
7056 		const char *init_args = "-s";
7057 		size_t init_args_length = strlen(init_args) + 1;
7058 
7059 		argv1 = scratch_addr;
7060 		error = copyout(init_args, argv1, init_args_length);
7061 		if (error) {
7062 			return error;
7063 		}
7064 
7065 		scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
7066 	}
7067 
7068 	if (proc_is64bit(p)) {
7069 		user64_addr_t argv64bit[3] = {};
7070 
7071 		argv64bit[0] = argv0;
7072 		argv64bit[1] = argv1;
7073 		argv64bit[2] = USER_ADDR_NULL;
7074 
7075 		error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
7076 		if (error) {
7077 			return error;
7078 		}
7079 	} else {
7080 		user32_addr_t argv32bit[3] = {};
7081 
7082 		argv32bit[0] = (user32_addr_t)argv0;
7083 		argv32bit[1] = (user32_addr_t)argv1;
7084 		argv32bit[2] = USER_ADDR_NULL;
7085 
7086 		error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
7087 		if (error) {
7088 			return error;
7089 		}
7090 	}
7091 
7092 	/*
7093 	 * Set up argument block for fake call to execve.
7094 	 */
7095 	init_exec_args.fname = argv0;
7096 	init_exec_args.argp = scratch_addr;
7097 	init_exec_args.envp = USER_ADDR_NULL;
7098 
7099 	/*
7100 	 * So that init task is set with uid,gid 0 token
7101 	 *
7102 	 * The access to the cred is safe:
7103 	 * the proc isn't running yet, it's stable.
7104 	 */
7105 	set_security_token(p, proc_ucred_unsafe(p));
7106 
7107 	return execve(p, &init_exec_args, retval);
7108 }
7109 
7110 static const char * init_programs[] = {
7111 #if DEBUG
7112 	"/usr/appleinternal/sbin/launchd.debug",
7113 #endif
7114 #if DEVELOPMENT || DEBUG
7115 	"/usr/appleinternal/sbin/launchd.development",
7116 #endif
7117 	"/sbin/launchd",
7118 };
7119 
7120 /*
7121  * load_init_program
7122  *
7123  * Description:	Load the "init" program; in most cases, this will be "launchd"
7124  *
7125  * Parameters:	p			Process to call execve() to create
7126  *					the "init" program
7127  *
7128  * Returns:	(void)
7129  *
7130  * Notes:	The process that is passed in is the first manufactured
7131  *		process on the system, and gets here via bsd_ast() firing
7132  *		for the first time.  This is done to ensure that bsd_init()
7133  *		has run to completion.
7134  *
7135  *		In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
7136  *		may be used to select a specific launchd executable. As with
7137  *		the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
7138  *		will force /sbin/launchd to be selected.
7139  *
7140  *              Search order by build:
7141  *
7142  * DEBUG	DEVELOPMENT	RELEASE		PATH
7143  * ----------------------------------------------------------------------------------
7144  * 1		1		NA		/usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
7145  * 2		NA		NA		/usr/appleinternal/sbin/launchd.debug
7146  * 3		2		NA		/usr/appleinternal/sbin/launchd.development
7147  * 4		3		1		/sbin/launchd
7148  */
7149 void
load_init_program(proc_t p)7150 load_init_program(proc_t p)
7151 {
7152 	uint32_t i;
7153 	int error;
7154 	vm_map_t map = current_map();
7155 	mach_vm_offset_t scratch_addr = 0;
7156 	mach_vm_size_t map_page_size = vm_map_page_size(map);
7157 
7158 	(void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size, VM_FLAGS_ANYWHERE, VM_KERN_MEMORY_NONE);
7159 #if CONFIG_MEMORYSTATUS
7160 	(void) memorystatus_init_at_boot_snapshot();
7161 #endif /* CONFIG_MEMORYSTATUS */
7162 
7163 #if DEBUG || DEVELOPMENT
7164 	/* Check for boot-arg suffix first */
7165 	char launchd_suffix[64];
7166 	if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
7167 		char launchd_path[128];
7168 		boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
7169 		    (strcmp(launchd_suffix, "release") == 0));
7170 
7171 		if (is_release_suffix) {
7172 			printf("load_init_program: attempting to load /sbin/launchd\n");
7173 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
7174 			if (!error) {
7175 				return;
7176 			}
7177 
7178 			panic("Process 1 exec of launchd.release failed, errno %d", error);
7179 		} else {
7180 			strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
7181 			strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
7182 
7183 			printf("load_init_program: attempting to load %s\n", launchd_path);
7184 			error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
7185 			if (!error) {
7186 				return;
7187 			} else if (error != ENOENT) {
7188 				printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
7189 			}
7190 		}
7191 	}
7192 #endif
7193 
7194 	error = ENOENT;
7195 	for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
7196 		printf("load_init_program: attempting to load %s\n", init_programs[i]);
7197 		error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
7198 		if (!error) {
7199 			return;
7200 		} else if (error != ENOENT) {
7201 			printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
7202 		}
7203 	}
7204 
7205 	panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
7206 }
7207 
7208 /*
7209  * load_return_to_errno
7210  *
7211  * Description:	Convert a load_return_t (Mach error) to an errno (BSD error)
7212  *
7213  * Parameters:	lrtn			Mach error number
7214  *
7215  * Returns:	(int)			BSD error number
7216  *		0			Success
7217  *		EBADARCH		Bad architecture
7218  *		EBADMACHO		Bad Mach object file
7219  *		ESHLIBVERS		Bad shared library version
7220  *		ENOMEM			Out of memory/resource shortage
7221  *		EACCES			Access denied
7222  *		ENOENT			Entry not found (usually "file does
7223  *					does not exist")
7224  *		EIO			An I/O error occurred
7225  *		EBADEXEC		The executable is corrupt/unknown
7226  */
7227 static int
load_return_to_errno(load_return_t lrtn)7228 load_return_to_errno(load_return_t lrtn)
7229 {
7230 	switch (lrtn) {
7231 	case LOAD_SUCCESS:
7232 		return 0;
7233 	case LOAD_BADARCH:
7234 		return EBADARCH;
7235 	case LOAD_BADMACHO:
7236 	case LOAD_BADMACHO_UPX:
7237 		return EBADMACHO;
7238 	case LOAD_SHLIB:
7239 		return ESHLIBVERS;
7240 	case LOAD_NOSPACE:
7241 	case LOAD_RESOURCE:
7242 		return ENOMEM;
7243 	case LOAD_PROTECT:
7244 		return EACCES;
7245 	case LOAD_ENOENT:
7246 		return ENOENT;
7247 	case LOAD_IOERROR:
7248 		return EIO;
7249 	case LOAD_DECRYPTFAIL:
7250 		return EAUTH;
7251 	case LOAD_FAILURE:
7252 	default:
7253 		return EBADEXEC;
7254 	}
7255 }
7256 
7257 #include <mach/mach_types.h>
7258 #include <mach/vm_prot.h>
7259 #include <mach/semaphore.h>
7260 #include <mach/sync_policy.h>
7261 #include <kern/clock.h>
7262 #include <mach/kern_return.h>
7263 
7264 /*
7265  * execargs_alloc
7266  *
7267  * Description:	Allocate the block of memory used by the execve arguments.
7268  *		At the same time, we allocate a page so that we can read in
7269  *		the first page of the image.
7270  *
7271  * Parameters:	struct image_params *	the image parameter block
7272  *
7273  * Returns:	0			Success
7274  *		EINVAL			Invalid argument
7275  *		EACCES			Permission denied
7276  *		EINTR			Interrupted function
7277  *		ENOMEM			Not enough space
7278  *
7279  * Notes:	This is a temporary allocation into the kernel address space
7280  *		to enable us to copy arguments in from user space.  This is
7281  *		necessitated by not mapping the process calling execve() into
7282  *		the kernel address space during the execve() system call.
7283  *
7284  *		We assemble the argument and environment, etc., into this
7285  *		region before copying it as a single block into the child
7286  *		process address space (at the top or bottom of the stack,
7287  *		depending on which way the stack grows; see the function
7288  *		exec_copyout_strings() for details).
7289  *
7290  *		This ends up with a second (possibly unnecessary) copy compared
7291  *		with assembing the data directly into the child address space,
7292  *		instead, but since we cannot be guaranteed that the parent has
7293  *		not modified its environment, we can't really know that it's
7294  *		really a block there as well.
7295  */
7296 
7297 
7298 static int execargs_waiters = 0;
7299 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
7300 
7301 static void
execargs_lock_lock(void)7302 execargs_lock_lock(void)
7303 {
7304 	lck_mtx_lock_spin(&execargs_cache_lock);
7305 }
7306 
7307 static void
execargs_lock_unlock(void)7308 execargs_lock_unlock(void)
7309 {
7310 	lck_mtx_unlock(&execargs_cache_lock);
7311 }
7312 
7313 static wait_result_t
execargs_lock_sleep(void)7314 execargs_lock_sleep(void)
7315 {
7316 	return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
7317 }
7318 
7319 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)7320 execargs_purgeable_allocate(char **execarg_address)
7321 {
7322 	mach_vm_offset_t addr = 0;
7323 	kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
7324 	    BSD_PAGEABLE_SIZE_PER_EXEC, VM_FLAGS_ANYWHERE | VM_FLAGS_PURGABLE,
7325 	    VM_KERN_MEMORY_NONE);
7326 	*execarg_address = (char *)addr;
7327 	assert(kr == KERN_SUCCESS);
7328 	return kr;
7329 }
7330 
7331 static kern_return_t
execargs_purgeable_reference(void * execarg_address)7332 execargs_purgeable_reference(void *execarg_address)
7333 {
7334 	int state = VM_PURGABLE_NONVOLATILE;
7335 	kern_return_t kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7336 
7337 	assert(kr == KERN_SUCCESS);
7338 	return kr;
7339 }
7340 
7341 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)7342 execargs_purgeable_volatilize(void *execarg_address)
7343 {
7344 	int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
7345 	kern_return_t kr;
7346 	kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7347 
7348 	assert(kr == KERN_SUCCESS);
7349 
7350 	return kr;
7351 }
7352 
7353 static void
execargs_wakeup_waiters(void)7354 execargs_wakeup_waiters(void)
7355 {
7356 	thread_wakeup(&execargs_free_count);
7357 }
7358 
7359 static int
execargs_alloc(struct image_params * imgp)7360 execargs_alloc(struct image_params *imgp)
7361 {
7362 	kern_return_t kret;
7363 	wait_result_t res;
7364 	int i, cache_index = -1;
7365 
7366 	execargs_lock_lock();
7367 
7368 	while (execargs_free_count == 0) {
7369 		execargs_waiters++;
7370 		res = execargs_lock_sleep();
7371 		execargs_waiters--;
7372 		if (res != THREAD_AWAKENED) {
7373 			execargs_lock_unlock();
7374 			return EINTR;
7375 		}
7376 	}
7377 
7378 	execargs_free_count--;
7379 
7380 	for (i = 0; i < execargs_cache_size; i++) {
7381 		vm_offset_t element = execargs_cache[i];
7382 		if (element) {
7383 			cache_index = i;
7384 			imgp->ip_strings = (char *)(execargs_cache[i]);
7385 			execargs_cache[i] = 0;
7386 			break;
7387 		}
7388 	}
7389 
7390 	assert(execargs_free_count >= 0);
7391 
7392 	execargs_lock_unlock();
7393 
7394 	if (cache_index == -1) {
7395 		kret = execargs_purgeable_allocate(&imgp->ip_strings);
7396 	} else {
7397 		kret = execargs_purgeable_reference(imgp->ip_strings);
7398 	}
7399 
7400 	assert(kret == KERN_SUCCESS);
7401 	if (kret != KERN_SUCCESS) {
7402 		return ENOMEM;
7403 	}
7404 
7405 	/* last page used to read in file headers */
7406 	imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
7407 	imgp->ip_strendp = imgp->ip_strings;
7408 	imgp->ip_argspace = NCARGS;
7409 	imgp->ip_strspace = (NCARGS + PAGE_SIZE);
7410 
7411 	return 0;
7412 }
7413 
7414 /*
7415  * execargs_free
7416  *
7417  * Description:	Free the block of memory used by the execve arguments and the
7418  *		first page of the executable by a previous call to the function
7419  *		execargs_alloc().
7420  *
7421  * Parameters:	struct image_params *	the image parameter block
7422  *
7423  * Returns:	0			Success
7424  *		EINVAL			Invalid argument
7425  *		EINTR			Oeration interrupted
7426  */
7427 static int
execargs_free(struct image_params * imgp)7428 execargs_free(struct image_params *imgp)
7429 {
7430 	kern_return_t kret;
7431 	int i;
7432 	boolean_t needs_wakeup = FALSE;
7433 
7434 	kret = execargs_purgeable_volatilize(imgp->ip_strings);
7435 
7436 	execargs_lock_lock();
7437 	execargs_free_count++;
7438 
7439 	for (i = 0; i < execargs_cache_size; i++) {
7440 		vm_offset_t element = execargs_cache[i];
7441 		if (element == 0) {
7442 			execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
7443 			imgp->ip_strings = NULL;
7444 			break;
7445 		}
7446 	}
7447 
7448 	assert(imgp->ip_strings == NULL);
7449 
7450 	if (execargs_waiters > 0) {
7451 		needs_wakeup = TRUE;
7452 	}
7453 
7454 	execargs_lock_unlock();
7455 
7456 	if (needs_wakeup == TRUE) {
7457 		execargs_wakeup_waiters();
7458 	}
7459 
7460 	return kret == KERN_SUCCESS ? 0 : EINVAL;
7461 }
7462 
7463 void
uthread_set_exec_data(struct uthread * uth,struct image_params * imgp)7464 uthread_set_exec_data(struct uthread *uth, struct image_params *imgp)
7465 {
7466 	uth->uu_save.uus_exec_data.imgp = imgp;
7467 }
7468 
7469 size_t
thread_get_current_exec_path(char * path,size_t size)7470 thread_get_current_exec_path(char *path, size_t size)
7471 {
7472 	struct uthread *uth = current_uthread();
7473 	struct image_params *imgp = uth->uu_save.uus_exec_data.imgp;
7474 	size_t string_size = 0;
7475 	char *exec_path;
7476 
7477 	if (path == NULL || imgp == NULL || imgp->ip_strings == NULL) {
7478 		return 0;
7479 	}
7480 
7481 	exec_path = imgp->ip_strings + strlen(EXECUTABLE_KEY);
7482 	string_size = imgp->ip_strendp - exec_path;
7483 	string_size = MIN(MAXPATHLEN, string_size);
7484 	string_size = MIN(size, string_size);
7485 
7486 	string_size = strlcpy(path, exec_path, string_size);
7487 	return string_size;
7488 }
7489 static void
exec_resettextvp(proc_t p,struct image_params * imgp)7490 exec_resettextvp(proc_t p, struct image_params *imgp)
7491 {
7492 	vnode_t vp;
7493 	off_t offset;
7494 	vnode_t tvp  = p->p_textvp;
7495 	int ret;
7496 
7497 	vp = imgp->ip_vp;
7498 	offset = imgp->ip_arch_offset;
7499 
7500 	if (vp == NULLVP) {
7501 		panic("exec_resettextvp: expected valid vp");
7502 	}
7503 
7504 	ret = vnode_ref(vp);
7505 	proc_lock(p);
7506 	if (ret == 0) {
7507 		p->p_textvp = vp;
7508 		p->p_textoff = offset;
7509 	} else {
7510 		p->p_textvp = NULLVP;   /* this is paranoia */
7511 		p->p_textoff = 0;
7512 	}
7513 	proc_unlock(p);
7514 
7515 	if (tvp != NULLVP) {
7516 		if (vnode_getwithref(tvp) == 0) {
7517 			vnode_rele(tvp);
7518 			vnode_put(tvp);
7519 		}
7520 	}
7521 }
7522 
7523 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
7524 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
7525 
7526 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)7527 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
7528 {
7529 	static char const nibble[] = "0123456789abcdef";
7530 
7531 	/* Apparently still the safest way to get a hex representation
7532 	 * of binary data.
7533 	 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
7534 	 * <rdar://problem/33328859> confusion around %*D/%nD in printf
7535 	 */
7536 	for (int i = 0; i < CS_CDHASH_LEN; ++i) {
7537 		str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
7538 		str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
7539 	}
7540 	str[CS_CDHASH_STRING_SIZE - 1] = 0;
7541 }
7542 
7543 /*
7544  * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
7545  *
7546  * Description: Waits for the userspace daemon to respond to the request
7547  *              we made. Function declared non inline to be visible in
7548  *		stackshots and spindumps as well as debugging.
7549  */
7550 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)7551 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
7552 {
7553 	return find_code_signature(task_access_port, new_pid);
7554 }
7555 
7556 /*
7557  * Update signature dependent process state, called by
7558  * process_signature.
7559  */
7560 static int
proc_process_signature(proc_t p,os_reason_t * signature_failure_reason)7561 proc_process_signature(proc_t p, os_reason_t *signature_failure_reason)
7562 {
7563 	int error = 0;
7564 	char const *error_msg = NULL;
7565 
7566 	kern_return_t kr = machine_task_process_signature(proc_get_task_raw(p), proc_platform(p), proc_sdk(p), &error_msg);
7567 
7568 	if (kr != KERN_SUCCESS) {
7569 		error = EINVAL;
7570 
7571 		if (error_msg != NULL) {
7572 			uint32_t error_msg_len = (uint32_t)strlen(error_msg) + 1;
7573 			mach_vm_address_t data_addr = 0;
7574 			int reason_error = 0;
7575 			int kcdata_error = 0;
7576 
7577 			os_reason_t reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7578 			reason->osr_flags = OS_REASON_FLAG_GENERATE_CRASH_REPORT | OS_REASON_FLAG_CONSISTENT_FAILURE;
7579 
7580 			if ((reason_error = os_reason_alloc_buffer_noblock(reason,
7581 			    kcdata_estimate_required_buffer_size(1, error_msg_len))) == 0 &&
7582 			    (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
7583 			    EXIT_REASON_USER_DESC, error_msg_len,
7584 			    &data_addr)) == KERN_SUCCESS) {
7585 				kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
7586 				    error_msg, error_msg_len);
7587 
7588 				if (mc_error != KERN_SUCCESS) {
7589 					printf("process_signature: failed to copy reason string (kcdata_memcpy error: %d)\n",
7590 					    mc_error);
7591 				}
7592 			} else {
7593 				printf("failed to allocate space for reason string (os_reason_alloc_buffer error: %d, kcdata error: %d, length: %u)\n",
7594 				    reason_error, kcdata_error, error_msg_len);
7595 			}
7596 
7597 			assert(*signature_failure_reason == NULL); // shouldn't have gotten so far
7598 			*signature_failure_reason = reason;
7599 		}
7600 	}
7601 	return error;
7602 }
7603 
7604 static int
process_signature(proc_t p,struct image_params * imgp)7605 process_signature(proc_t p, struct image_params *imgp)
7606 {
7607 	mach_port_t port = IPC_PORT_NULL;
7608 	kern_return_t kr = KERN_FAILURE;
7609 	int error = EACCES;
7610 	boolean_t unexpected_failure = FALSE;
7611 	struct cs_blob *csb;
7612 	boolean_t require_success = FALSE;
7613 	int spawn = (imgp->ip_flags & IMGPF_SPAWN);
7614 	const int vfexec = 0;
7615 	os_reason_t signature_failure_reason = OS_REASON_NULL;
7616 
7617 	/*
7618 	 * Override inherited code signing flags with the
7619 	 * ones for the process that is being successfully
7620 	 * loaded
7621 	 */
7622 	proc_lock(p);
7623 	proc_csflags_update(p, imgp->ip_csflags);
7624 	proc_unlock(p);
7625 
7626 	/* Set the switch_protect flag on the map */
7627 	if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
7628 		vm_map_switch_protect(get_task_map(proc_task(p)), TRUE);
7629 	}
7630 	/* set the cs_enforced flags in the map */
7631 	if (proc_getcsflags(p) & CS_ENFORCEMENT) {
7632 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), TRUE);
7633 	} else {
7634 		vm_map_cs_enforcement_set(get_task_map(proc_task(p)), FALSE);
7635 	}
7636 
7637 	/*
7638 	 * image activation may be failed due to policy
7639 	 * which is unexpected but security framework does not
7640 	 * approve of exec, kill and return immediately.
7641 	 */
7642 	if (imgp->ip_mac_return != 0) {
7643 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7644 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
7645 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7646 		error = imgp->ip_mac_return;
7647 		unexpected_failure = TRUE;
7648 		goto done;
7649 	}
7650 
7651 	if (imgp->ip_cs_error != OS_REASON_NULL) {
7652 		signature_failure_reason = imgp->ip_cs_error;
7653 		imgp->ip_cs_error = OS_REASON_NULL;
7654 		error = EACCES;
7655 		goto done;
7656 	}
7657 
7658 	/* call the launch constraints hook */
7659 	os_reason_t launch_constraint_reason;
7660 	if ((error = mac_proc_check_launch_constraints(p, imgp, &launch_constraint_reason)) != 0) {
7661 		signature_failure_reason = launch_constraint_reason;
7662 		goto done;
7663 	}
7664 
7665 #if XNU_TARGET_OS_OSX
7666 	/* Check for platform passed in spawn attr if iOS binary is being spawned */
7667 	if (proc_platform(p) == PLATFORM_IOS) {
7668 		struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
7669 		if (psa == NULL || psa->psa_platform == 0) {
7670 			boolean_t no_sandbox_entitled = FALSE;
7671 #if DEBUG || DEVELOPMENT
7672 			/*
7673 			 * Allow iOS binaries to spawn on internal systems
7674 			 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
7675 			 * boot-arg set to true
7676 			 */
7677 			if (unentitled_ios_sim_launch) {
7678 				no_sandbox_entitled = TRUE;
7679 			} else {
7680 				no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
7681 				    (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
7682 			}
7683 #endif /* DEBUG || DEVELOPMENT */
7684 			if (!no_sandbox_entitled) {
7685 				signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7686 				    EXEC_EXIT_REASON_WRONG_PLATFORM);
7687 				error = EACCES;
7688 				goto done;
7689 			}
7690 			printf("Allowing spawn of iOS binary %s since it has "
7691 			    "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
7692 			    "boot-arg set to true\n", p->p_name);
7693 		} else if (psa->psa_platform != PLATFORM_IOS) {
7694 			/* Simulator binary spawned with wrong platform */
7695 			signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7696 			    EXEC_EXIT_REASON_WRONG_PLATFORM);
7697 			error = EACCES;
7698 			goto done;
7699 		} else {
7700 			printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
7701 			    p->p_name);
7702 		}
7703 	}
7704 #endif /* XNU_TARGET_OS_OSX */
7705 
7706 	/* If the code signature came through the image activation path, we skip the
7707 	 * taskgated / externally attached path. */
7708 	if (imgp->ip_csflags & CS_SIGNED) {
7709 		error = 0;
7710 		goto done;
7711 	}
7712 
7713 	/* The rest of the code is for signatures that either already have been externally
7714 	 * attached (likely, but not necessarily by a previous run through the taskgated
7715 	 * path), or that will now be attached by taskgated. */
7716 
7717 	kr = task_get_task_access_port(proc_task(p), &port);
7718 	if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
7719 		error = 0;
7720 		if (require_success) {
7721 			KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7722 			    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
7723 			signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
7724 			error = EACCES;
7725 		}
7726 		goto done;
7727 	}
7728 
7729 	/*
7730 	 * taskgated returns KERN_SUCCESS if it has completed its work
7731 	 * and the exec should continue, KERN_FAILURE if the exec should
7732 	 * fail, or it may error out with different error code in an
7733 	 * event of mig failure (e.g. process was signalled during the
7734 	 * rpc call, taskgated died, mig server died etc.).
7735 	 */
7736 
7737 	kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
7738 	switch (kr) {
7739 	case KERN_SUCCESS:
7740 		error = 0;
7741 		break;
7742 	case KERN_FAILURE:
7743 		error = EACCES;
7744 
7745 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7746 		    proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
7747 		signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
7748 		goto done;
7749 	default:
7750 		error = EACCES;
7751 
7752 		KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7753 		    proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
7754 		signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
7755 		unexpected_failure = TRUE;
7756 		goto done;
7757 	}
7758 
7759 	/* Only do this if exec_resettextvp() did not fail */
7760 	if (p->p_textvp != NULLVP) {
7761 		csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
7762 
7763 		if (csb != NULL) {
7764 			/* As the enforcement we can do here is very limited, we only allow things that
7765 			 * are the only reason why this code path still exists:
7766 			 * Adhoc signed non-platform binaries without special cs_flags and without any
7767 			 * entitlements (unrestricted ones still pass AMFI). */
7768 			if (
7769 				/* Revalidate the blob if necessary through bumped generation count. */
7770 				(ubc_cs_generation_check(p->p_textvp) == 0 ||
7771 				ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
7772 				/* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
7773 				(csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
7774 				/* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
7775 				csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
7776 				CSSLOT_SIGNATURESLOT,
7777 				CSMAGIC_BLOBWRAPPER) == NULL &&
7778 				/* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
7779 				csb->csb_platform_binary == 0 &&
7780 				/* No entitlements, not even unrestricted ones. */
7781 				csb->csb_entitlements_blob == NULL &&
7782 				csb->csb_der_entitlements_blob == NULL) {
7783 				proc_lock(p);
7784 				proc_csflags_set(p, CS_SIGNED | CS_VALID);
7785 				proc_unlock(p);
7786 			} else {
7787 				uint8_t cdhash[CS_CDHASH_LEN];
7788 				char cdhash_string[CS_CDHASH_STRING_SIZE];
7789 				proc_getcdhash(p, cdhash);
7790 				cdhash_to_string(cdhash_string, cdhash);
7791 				printf("ignoring detached code signature on '%s' with cdhash '%s' "
7792 				    "because it is invalid, or not a simple adhoc signature.\n",
7793 				    p->p_name, cdhash_string);
7794 			}
7795 		}
7796 	}
7797 
7798 done:
7799 	if (0 == error) {
7800 		/*
7801 		 * Update the new process's signature-dependent process state.
7802 		 * state.
7803 		 */
7804 
7805 		error = proc_process_signature(p, &signature_failure_reason);
7806 	}
7807 
7808 	if (0 == error) {
7809 		/*
7810 		 * Update the new main thread's signature-dependent thread
7811 		 * state. This was also called when the thread was created,
7812 		 * but for the main thread the signature was not yet attached
7813 		 * at that time.
7814 		 */
7815 		kr = thread_process_signature(imgp->ip_new_thread, proc_get_task_raw(p));
7816 
7817 		if (kr != KERN_SUCCESS) {
7818 			error = EINVAL;
7819 			signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MACHINE_THREAD);
7820 		}
7821 	}
7822 
7823 	if (0 == error) {
7824 		/* The process's code signature related properties are
7825 		 * fully set up, so this is an opportune moment to log
7826 		 * platform binary execution, if desired. */
7827 		if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
7828 			uint8_t cdhash[CS_CDHASH_LEN];
7829 			char cdhash_string[CS_CDHASH_STRING_SIZE];
7830 			proc_getcdhash(p, cdhash);
7831 			cdhash_to_string(cdhash_string, cdhash);
7832 
7833 			os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
7834 			    "'%s' with cdhash %s\n", p->p_name, cdhash_string);
7835 		}
7836 	} else {
7837 		if (!unexpected_failure) {
7838 			proc_csflags_set(p, CS_KILLED);
7839 		}
7840 		/* make very sure execution fails */
7841 		if (vfexec || spawn) {
7842 			assert(signature_failure_reason != OS_REASON_NULL);
7843 			psignal_vfork_with_reason(p, proc_task(p), imgp->ip_new_thread,
7844 			    SIGKILL, signature_failure_reason);
7845 			signature_failure_reason = OS_REASON_NULL;
7846 			error = 0;
7847 		} else {
7848 			assert(signature_failure_reason != OS_REASON_NULL);
7849 			psignal_with_reason(p, SIGKILL, signature_failure_reason);
7850 			signature_failure_reason = OS_REASON_NULL;
7851 		}
7852 	}
7853 
7854 	if (port != IPC_PORT_NULL) {
7855 		ipc_port_release_send(port);
7856 	}
7857 
7858 	/* If we hit this, we likely would have leaked an exit reason */
7859 	assert(signature_failure_reason == OS_REASON_NULL);
7860 	return error;
7861 }
7862 
7863 /*
7864  * Typically as soon as we start executing this process, the
7865  * first instruction will trigger a VM fault to bring the text
7866  * pages (as executable) into the address space, followed soon
7867  * thereafter by dyld data structures (for dynamic executable).
7868  * To optimize this, as well as improve support for hardware
7869  * debuggers that can only access resident pages present
7870  * in the process' page tables, we prefault some pages if
7871  * possible. Errors are non-fatal.
7872  */
7873 #ifndef PREVENT_CALLER_STACK_USE
7874 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
7875 #endif
7876 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(proc_t p __unused,struct image_params * imgp,load_result_t * load_result)7877 exec_prefault_data(proc_t p __unused, struct image_params *imgp, load_result_t *load_result)
7878 {
7879 	int ret;
7880 	size_t expected_all_image_infos_size;
7881 	kern_return_t kr;
7882 
7883 	/*
7884 	 * Prefault executable or dyld entry point.
7885 	 */
7886 	if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7887 		DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
7888 	}
7889 	kr = vm_fault(current_map(),
7890 	    vm_map_trunc_page(load_result->entry_point,
7891 	    vm_map_page_mask(current_map())),
7892 	    VM_PROT_READ | VM_PROT_EXECUTE,
7893 	    FALSE, VM_KERN_MEMORY_NONE,
7894 	    THREAD_UNINT, NULL, 0);
7895 	if (kr != KERN_SUCCESS) {
7896 		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);
7897 	}
7898 
7899 	if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7900 		expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
7901 	} else {
7902 		expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
7903 	}
7904 
7905 	/* Decode dyld anchor structure from <mach-o/dyld_images.h> */
7906 	if (load_result->dynlinker &&
7907 	    load_result->all_image_info_addr &&
7908 	    load_result->all_image_info_size >= expected_all_image_infos_size) {
7909 		union {
7910 			struct user64_dyld_all_image_infos      infos64;
7911 			struct user32_dyld_all_image_infos      infos32;
7912 		} all_image_infos;
7913 
7914 		/*
7915 		 * Pre-fault to avoid copyin() going through the trap handler
7916 		 * and recovery path.
7917 		 */
7918 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7919 			DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
7920 		}
7921 		kr = vm_fault(current_map(),
7922 		    vm_map_trunc_page(load_result->all_image_info_addr,
7923 		    vm_map_page_mask(current_map())),
7924 		    VM_PROT_READ | VM_PROT_WRITE,
7925 		    FALSE, VM_KERN_MEMORY_NONE,
7926 		    THREAD_UNINT, NULL, 0);
7927 		if (kr != KERN_SUCCESS) {
7928 //			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);
7929 		}
7930 		if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
7931 			/* all_image_infos straddles a page */
7932 			kr = vm_fault(current_map(),
7933 			    vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
7934 			    vm_map_page_mask(current_map())),
7935 			    VM_PROT_READ | VM_PROT_WRITE,
7936 			    FALSE, VM_KERN_MEMORY_NONE,
7937 			    THREAD_UNINT, NULL, 0);
7938 			if (kr != KERN_SUCCESS) {
7939 //				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);
7940 			}
7941 		}
7942 
7943 		if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7944 			DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
7945 		}
7946 		ret = copyin((user_addr_t)load_result->all_image_info_addr,
7947 		    &all_image_infos,
7948 		    expected_all_image_infos_size);
7949 		if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
7950 			user_addr_t notification_address;
7951 			user_addr_t dyld_image_address;
7952 			user_addr_t dyld_version_address;
7953 			user_addr_t dyld_all_image_infos_address;
7954 			user_addr_t dyld_slide_amount;
7955 
7956 			if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7957 				notification_address = (user_addr_t)all_image_infos.infos64.notification;
7958 				dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
7959 				dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
7960 				dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
7961 			} else {
7962 				notification_address = all_image_infos.infos32.notification;
7963 				dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
7964 				dyld_version_address = all_image_infos.infos32.dyldVersion;
7965 				dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
7966 			}
7967 
7968 			/*
7969 			 * dyld statically sets up the all_image_infos in its Mach-O
7970 			 * binary at static link time, with pointers relative to its default
7971 			 * load address. Since ASLR might slide dyld before its first
7972 			 * instruction is executed, "dyld_slide_amount" tells us how far
7973 			 * dyld was loaded compared to its default expected load address.
7974 			 * All other pointers into dyld's image should be adjusted by this
7975 			 * amount. At some point later, dyld will fix up pointers to take
7976 			 * into account the slide, at which point the all_image_infos_address
7977 			 * field in the structure will match the runtime load address, and
7978 			 * "dyld_slide_amount" will be 0, if we were to consult it again.
7979 			 */
7980 
7981 			dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
7982 
7983 #if 0
7984 			kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
7985 			    (uint64_t)load_result->all_image_info_addr,
7986 			    all_image_infos.infos32.version,
7987 			    (uint64_t)notification_address,
7988 			    (uint64_t)dyld_image_address,
7989 			    (uint64_t)dyld_version_address,
7990 			    (uint64_t)dyld_all_image_infos_address);
7991 #endif
7992 
7993 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7994 				DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
7995 			}
7996 			kr = vm_fault(current_map(),
7997 			    vm_map_trunc_page(notification_address + dyld_slide_amount,
7998 			    vm_map_page_mask(current_map())),
7999 			    VM_PROT_READ | VM_PROT_EXECUTE,
8000 			    FALSE, VM_KERN_MEMORY_NONE,
8001 			    THREAD_UNINT, NULL, 0);
8002 			if (kr != KERN_SUCCESS) {
8003 //				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);
8004 			}
8005 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8006 				DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
8007 			}
8008 			kr = vm_fault(current_map(),
8009 			    vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
8010 			    vm_map_page_mask(current_map())),
8011 			    VM_PROT_READ | VM_PROT_EXECUTE,
8012 			    FALSE, VM_KERN_MEMORY_NONE,
8013 			    THREAD_UNINT, NULL, 0);
8014 			if (kr != KERN_SUCCESS) {
8015 //				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);
8016 			}
8017 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8018 				DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
8019 			}
8020 			kr = vm_fault(current_map(),
8021 			    vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
8022 			    vm_map_page_mask(current_map())),
8023 			    VM_PROT_READ,
8024 			    FALSE, VM_KERN_MEMORY_NONE,
8025 			    THREAD_UNINT, NULL, 0);
8026 			if (kr != KERN_SUCCESS) {
8027 //				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);
8028 			}
8029 			if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8030 				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);
8031 			}
8032 			kr = vm_fault(current_map(),
8033 			    vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
8034 			    vm_map_page_mask(current_map())),
8035 			    VM_PROT_READ | VM_PROT_WRITE,
8036 			    FALSE, VM_KERN_MEMORY_NONE,
8037 			    THREAD_UNINT, NULL, 0);
8038 			if (kr != KERN_SUCCESS) {
8039 //				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);
8040 			}
8041 		}
8042 	}
8043 }
8044 
8045 static int
8046 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
8047 {
8048 #pragma unused(oidp, arg2, req)
8049 	int changed;
8050 	errno_t error;
8051 	uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
8052 
8053 	error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
8054 	if (error) {
8055 		return error;
8056 	}
8057 
8058 	if (changed) {
8059 		os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
8060 	}
8061 
8062 	return 0;
8063 }
8064 
8065 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
8066