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