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
136 #include <kern/sched_prim.h> /* thread_wakeup() */
137 #include <kern/affinity.h>
138 #include <kern/assert.h>
139 #include <kern/task.h>
140 #include <kern/coalition.h>
141 #include <kern/policy_internal.h>
142 #include <kern/kalloc.h>
143 #include <kern/zalloc.h> /* zone_userspace_reboot_checks() */
144
145 #include <os/log.h>
146
147 #if CONFIG_MACF
148 #include <security/mac_framework.h>
149 #include <security/mac_mach_internal.h>
150 #endif
151
152 #if CONFIG_AUDIT
153 #include <bsm/audit_kevents.h>
154 #endif
155
156 #if CONFIG_ARCADE
157 #include <kern/arcade.h>
158 #endif
159
160 #include <vm/vm_map.h>
161 #include <vm/vm_kern.h>
162 #include <vm/vm_protos.h>
163 #include <vm/vm_kern.h>
164 #include <vm/vm_fault.h>
165 #include <vm/vm_pageout.h>
166 #include <vm/pmap.h>
167
168 #include <kdp/kdp_dyld.h>
169
170 #include <machine/machine_routines.h>
171 #include <machine/pal_routines.h>
172
173 #include <pexpert/pexpert.h>
174
175 #if CONFIG_MEMORYSTATUS
176 #include <sys/kern_memorystatus.h>
177 #endif
178
179 #include <IOKit/IOBSD.h>
180 #include <IOKit/IOPlatformExpert.h>
181
182 #include "kern_exec_internal.h"
183
184 extern boolean_t vm_darkwake_mode;
185
186 /* enable crash reports on various exec failures */
187 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
188
189 #if XNU_TARGET_OS_OSX
190 #if __has_feature(ptrauth_calls)
191 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
192 #endif /* __has_feature(ptrauth_calls) */
193
194 #if DEBUG || DEVELOPMENT
195 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
196 #endif /* DEBUG || DEVELOPMENT */
197 #endif /* XNU_TARGET_OS_OSX */
198
199 #if CONFIG_DTRACE
200 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
201 extern void dtrace_proc_exec(proc_t);
202 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
203
204 /*
205 * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
206 * we will store its value before actually calling it.
207 */
208 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
209
210 #include <sys/dtrace_ptss.h>
211 #endif
212
213 #if __has_feature(ptrauth_calls)
214 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
215 "vm_shared_region_per_team_id", 1);
216 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
217 "vm_shared_region_by_entitlement", 1);
218
219 /* Upon userland request, reslide the shared cache. */
220 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
221 "vm_shared_region_reslide_aslr",
222 #if CONFIG_RESLIDE_SHARED_CACHE
223 1
224 #else
225 0
226 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
227 );
228
229 /*
230 * Flag to control what processes should get shared cache randomize resliding
231 * after a fault in the shared cache region:
232 *
233 * 0 - all processes get a new randomized slide
234 * 1 - only platform processes get a new randomized slide
235 */
236 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
237 "vm_shared_region_reslide_restrict", 1);
238
239 #if DEVELOPMENT || DEBUG
240 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
241 CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
242 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
243 CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
244 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
245 CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
246 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
247 CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
248 #endif
249 #endif /* __has_feature(ptrauth_calls) */
250
251 /*
252 * Enable DriverKit shared region. This is disabled by default, and kernelmanagerd/driverkitd will set this to 1 if it
253 * detects the presence of a DriverKit shared cache.
254 */
255 int vm_enable_driverkit_shared_region = 0;
256
257 thread_t fork_create_child(task_t parent_task,
258 coalition_t *parent_coalition,
259 proc_t child_proc,
260 int inherit_memory,
261 int is_64bit_addr,
262 int is_64bit_data,
263 int in_exec);
264 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
265 extern void task_set_did_exec_flag(task_t task);
266 extern void task_clear_exec_copy_flag(task_t task);
267 proc_t proc_exec_switch_task(proc_t p, task_t old_task, 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 * Mach things for which prototypes are unavailable from Mach headers
282 */
283 #define IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND 0x1
284 void ipc_task_reset(
285 task_t task);
286 void ipc_thread_reset(
287 thread_t thread);
288 kern_return_t ipc_object_copyin(
289 ipc_space_t space,
290 mach_port_name_t name,
291 mach_msg_type_name_t msgt_name,
292 ipc_object_t *objectp,
293 mach_port_context_t context,
294 mach_msg_guard_flags_t *guard_flags,
295 uint32_t kmsg_flags);
296 void ipc_port_release_send(ipc_port_t);
297
298 #if DEVELOPMENT || DEBUG
299 void task_importance_update_owner_info(task_t);
300 #endif
301
302 extern struct savearea *get_user_regs(thread_t);
303
304 __attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
305
306 #include <kern/thread.h>
307 #include <kern/task.h>
308 #include <kern/ast.h>
309 #include <kern/mach_loader.h>
310 #include <kern/mach_fat.h>
311 #include <mach-o/fat.h>
312 #include <mach-o/loader.h>
313 #include <machine/vmparam.h>
314 #include <sys/imgact.h>
315
316 #include <sys/sdt.h>
317
318
319 /*
320 * EAI_ITERLIMIT The maximum number of times to iterate an image
321 * activator in exec_activate_image() before treating
322 * it as malformed/corrupt.
323 */
324 #define EAI_ITERLIMIT 3
325
326 /*
327 * For #! interpreter parsing
328 */
329 #define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
330 #define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
331
332 extern vm_map_t bsd_pageable_map;
333 extern const struct fileops vnops;
334 extern int nextpidversion;
335
336
337 #define USER_ADDR_ALIGN(addr, val) \
338 ( ( (user_addr_t)(addr) + (val) - 1) \
339 & ~((val) - 1) )
340
341 /*
342 * For subsystem root support
343 */
344 #define SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT "com.apple.private.spawn-subsystem-root"
345
346 /* Platform Code Exec Logging */
347 static int platform_exec_logging = 0;
348
349 SYSCTL_DECL(_security_mac);
350
351 SYSCTL_INT(_security_mac, OID_AUTO, platform_exec_logging, CTLFLAG_RW, &platform_exec_logging, 0,
352 "log cdhashes for all platform binary executions");
353
354 static os_log_t peLog = OS_LOG_DEFAULT;
355
356 struct exec_port_actions {
357 uint32_t portwatch_count;
358 uint32_t registered_count;
359 ipc_port_t *portwatch_array;
360 ipc_port_t *registered_array;
361 };
362
363 struct image_params; /* Forward */
364 static int exec_activate_image(struct image_params *imgp);
365 static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
366 static int load_return_to_errno(load_return_t lrtn);
367 static int execargs_alloc(struct image_params *imgp);
368 static int execargs_free(struct image_params *imgp);
369 static int exec_check_permissions(struct image_params *imgp);
370 static int exec_extract_strings(struct image_params *imgp);
371 static int exec_add_apple_strings(struct image_params *imgp, const load_result_t *load_result);
372 static int exec_handle_sugid(struct image_params *imgp);
373 static int sugid_scripts = 0;
374 SYSCTL_INT(_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
375 static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
376 static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
377 static void exec_resettextvp(proc_t, struct image_params *);
378 static int check_for_signature(proc_t, struct image_params *);
379 static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
380 static errno_t exec_handle_port_actions(struct image_params *imgp,
381 struct exec_port_actions *port_actions);
382 static errno_t exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
383 task_role_t psa_darwin_role, struct exec_port_actions *port_actions);
384 static void exec_port_actions_destroy(struct exec_port_actions *port_actions);
385
386 /*
387 * exec_add_user_string
388 *
389 * Add the requested string to the string space area.
390 *
391 * Parameters; struct image_params * image parameter block
392 * user_addr_t string to add to strings area
393 * int segment from which string comes
394 * boolean_t TRUE if string contributes to NCARGS
395 *
396 * Returns: 0 Success
397 * !0 Failure errno from copyinstr()
398 *
399 * Implicit returns:
400 * (imgp->ip_strendp) updated location of next add, if any
401 * (imgp->ip_strspace) updated byte count of space remaining
402 * (imgp->ip_argspace) updated byte count of space in NCARGS
403 */
404 __attribute__((noinline))
405 static int
exec_add_user_string(struct image_params * imgp,user_addr_t str,int seg,boolean_t is_ncargs)406 exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
407 {
408 int error = 0;
409
410 do {
411 size_t len = 0;
412 int space;
413
414 if (is_ncargs) {
415 space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
416 } else {
417 space = imgp->ip_strspace;
418 }
419
420 if (space <= 0) {
421 error = E2BIG;
422 break;
423 }
424
425 if (!UIO_SEG_IS_USER_SPACE(seg)) {
426 char *kstr = CAST_DOWN(char *, str); /* SAFE */
427 error = copystr(kstr, imgp->ip_strendp, space, &len);
428 } else {
429 error = copyinstr(str, imgp->ip_strendp, space, &len);
430 }
431
432 imgp->ip_strendp += len;
433 imgp->ip_strspace -= len;
434 if (is_ncargs) {
435 imgp->ip_argspace -= len;
436 }
437 } while (error == ENAMETOOLONG);
438
439 return error;
440 }
441
442 /*
443 * dyld is now passed the executable path as a getenv-like variable
444 * in the same fashion as the stack_guard and malloc_entropy keys.
445 */
446 #define EXECUTABLE_KEY "executable_path="
447
448 /*
449 * exec_save_path
450 *
451 * To support new app package launching for Mac OS X, the dyld needs the
452 * first argument to execve() stored on the user stack.
453 *
454 * Save the executable path name at the bottom of the strings area and set
455 * the argument vector pointer to the location following that to indicate
456 * the start of the argument and environment tuples, setting the remaining
457 * string space count to the size of the string area minus the path length.
458 *
459 * Parameters; struct image_params * image parameter block
460 * char * path used to invoke program
461 * int segment from which path comes
462 *
463 * Returns: int 0 Success
464 * EFAULT Bad address
465 * copy[in]str:EFAULT Bad address
466 * copy[in]str:ENAMETOOLONG Filename too long
467 *
468 * Implicit returns:
469 * (imgp->ip_strings) saved path
470 * (imgp->ip_strspace) space remaining in ip_strings
471 * (imgp->ip_strendp) start of remaining copy area
472 * (imgp->ip_argspace) space remaining of NCARGS
473 * (imgp->ip_applec) Initial applev[0]
474 *
475 * Note: We have to do this before the initial namei() since in the
476 * path contains symbolic links, namei() will overwrite the
477 * original path buffer contents. If the last symbolic link
478 * resolved was a relative pathname, we would lose the original
479 * "path", which could be an absolute pathname. This might be
480 * unacceptable for dyld.
481 */
482 static int
exec_save_path(struct image_params * imgp,user_addr_t path,int seg,const char ** excpath)483 exec_save_path(struct image_params *imgp, user_addr_t path, int seg, const char **excpath)
484 {
485 int error;
486 size_t len;
487 char *kpath;
488
489 // imgp->ip_strings can come out of a cache, so we need to obliterate the
490 // old path.
491 memset(imgp->ip_strings, '\0', strlen(EXECUTABLE_KEY) + MAXPATHLEN);
492
493 len = MIN(MAXPATHLEN, imgp->ip_strspace);
494
495 switch (seg) {
496 case UIO_USERSPACE32:
497 case UIO_USERSPACE64: /* Same for copyin()... */
498 error = copyinstr(path, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
499 break;
500 case UIO_SYSSPACE:
501 kpath = CAST_DOWN(char *, path); /* SAFE */
502 error = copystr(kpath, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
503 break;
504 default:
505 error = EFAULT;
506 break;
507 }
508
509 if (!error) {
510 bcopy(EXECUTABLE_KEY, imgp->ip_strings, strlen(EXECUTABLE_KEY));
511 len += strlen(EXECUTABLE_KEY);
512
513 imgp->ip_strendp += len;
514 imgp->ip_strspace -= len;
515
516 if (excpath) {
517 *excpath = imgp->ip_strings + strlen(EXECUTABLE_KEY);
518 }
519 }
520
521 return error;
522 }
523
524 /*
525 * exec_reset_save_path
526 *
527 * If we detect a shell script, we need to reset the string area
528 * state so that the interpreter can be saved onto the stack.
529 *
530 * Parameters; struct image_params * image parameter block
531 *
532 * Returns: int 0 Success
533 *
534 * Implicit returns:
535 * (imgp->ip_strings) saved path
536 * (imgp->ip_strspace) space remaining in ip_strings
537 * (imgp->ip_strendp) start of remaining copy area
538 * (imgp->ip_argspace) space remaining of NCARGS
539 *
540 */
541 static int
exec_reset_save_path(struct image_params * imgp)542 exec_reset_save_path(struct image_params *imgp)
543 {
544 imgp->ip_strendp = imgp->ip_strings;
545 imgp->ip_argspace = NCARGS;
546 imgp->ip_strspace = (NCARGS + PAGE_SIZE);
547
548 return 0;
549 }
550
551 /*
552 * exec_shell_imgact
553 *
554 * Image activator for interpreter scripts. If the image begins with
555 * the characters "#!", then it is an interpreter script. Verify the
556 * length of the script line indicating the interpreter is not in
557 * excess of the maximum allowed size. If this is the case, then
558 * break out the arguments, if any, which are separated by white
559 * space, and copy them into the argument save area as if they were
560 * provided on the command line before all other arguments. The line
561 * ends when we encounter a comment character ('#') or newline.
562 *
563 * Parameters; struct image_params * image parameter block
564 *
565 * Returns: -1 not an interpreter (keep looking)
566 * -3 Success: interpreter: relookup
567 * >0 Failure: interpreter: error number
568 *
569 * A return value other than -1 indicates subsequent image activators should
570 * not be given the opportunity to attempt to activate the image.
571 */
572 static int
exec_shell_imgact(struct image_params * imgp)573 exec_shell_imgact(struct image_params *imgp)
574 {
575 char *vdata = imgp->ip_vdata;
576 char *ihp;
577 char *line_startp, *line_endp;
578 char *interp;
579
580 /*
581 * Make sure it's a shell script. If we've already redirected
582 * from an interpreted file once, don't do it again.
583 */
584 if (vdata[0] != '#' ||
585 vdata[1] != '!' ||
586 (imgp->ip_flags & IMGPF_INTERPRET) != 0) {
587 return -1;
588 }
589
590 if (imgp->ip_origcputype != 0) {
591 /* Fat header previously matched, don't allow shell script inside */
592 return -1;
593 }
594
595 imgp->ip_flags |= IMGPF_INTERPRET;
596 imgp->ip_interp_sugid_fd = -1;
597 imgp->ip_interp_buffer[0] = '\0';
598
599 /* Check to see if SUGID scripts are permitted. If they aren't then
600 * clear the SUGID bits.
601 * imgp->ip_vattr is known to be valid.
602 */
603 if (sugid_scripts == 0) {
604 imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
605 }
606
607 /* Try to find the first non-whitespace character */
608 for (ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++) {
609 if (IS_EOL(*ihp)) {
610 /* Did not find interpreter, "#!\n" */
611 return ENOEXEC;
612 } else if (IS_WHITESPACE(*ihp)) {
613 /* Whitespace, like "#! /bin/sh\n", keep going. */
614 } else {
615 /* Found start of interpreter */
616 break;
617 }
618 }
619
620 if (ihp == &vdata[IMG_SHSIZE]) {
621 /* All whitespace, like "#! " */
622 return ENOEXEC;
623 }
624
625 line_startp = ihp;
626
627 /* Try to find the end of the interpreter+args string */
628 for (; ihp < &vdata[IMG_SHSIZE]; ihp++) {
629 if (IS_EOL(*ihp)) {
630 /* Got it */
631 break;
632 } else {
633 /* Still part of interpreter or args */
634 }
635 }
636
637 if (ihp == &vdata[IMG_SHSIZE]) {
638 /* A long line, like "#! blah blah blah" without end */
639 return ENOEXEC;
640 }
641
642 /* Backtrack until we find the last non-whitespace */
643 while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
644 ihp--;
645 }
646
647 /* The character after the last non-whitespace is our logical end of line */
648 line_endp = ihp + 1;
649
650 /*
651 * Now we have pointers to the usable part of:
652 *
653 * "#! /usr/bin/int first second third \n"
654 * ^ line_startp ^ line_endp
655 */
656
657 /* copy the interpreter name */
658 interp = imgp->ip_interp_buffer;
659 for (ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++) {
660 *interp++ = *ihp;
661 }
662 *interp = '\0';
663
664 exec_reset_save_path(imgp);
665 exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
666 UIO_SYSSPACE, NULL);
667
668 /* Copy the entire interpreter + args for later processing into argv[] */
669 interp = imgp->ip_interp_buffer;
670 for (ihp = line_startp; (ihp < line_endp); ihp++) {
671 *interp++ = *ihp;
672 }
673 *interp = '\0';
674
675 #if CONFIG_SETUID
676 /*
677 * If we have an SUID or SGID script, create a file descriptor
678 * from the vnode and pass /dev/fd/%d instead of the actual
679 * path name so that the script does not get opened twice
680 */
681 if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
682 proc_t p;
683 struct fileproc *fp;
684 int fd;
685 int error;
686
687 p = vfs_context_proc(imgp->ip_vfs_context);
688 error = falloc(p, &fp, &fd, imgp->ip_vfs_context);
689 if (error) {
690 return error;
691 }
692
693 fp->fp_glob->fg_flag = FREAD;
694 fp->fp_glob->fg_ops = &vnops;
695 fp_set_data(fp, imgp->ip_vp);
696
697 proc_fdlock(p);
698 procfdtbl_releasefd(p, fd, NULL);
699 fp_drop(p, fd, fp, 1);
700 proc_fdunlock(p);
701 vnode_ref(imgp->ip_vp);
702
703 imgp->ip_interp_sugid_fd = fd;
704 }
705 #endif /* CONFIG_SETUID */
706
707 return -3;
708 }
709
710
711
712 /*
713 * exec_fat_imgact
714 *
715 * Image activator for fat 1.0 binaries. If the binary is fat, then we
716 * need to select an image from it internally, and make that the image
717 * we are going to attempt to execute. At present, this consists of
718 * reloading the first page for the image with a first page from the
719 * offset location indicated by the fat header.
720 *
721 * Parameters; struct image_params * image parameter block
722 *
723 * Returns: -1 not a fat binary (keep looking)
724 * -2 Success: encapsulated binary: reread
725 * >0 Failure: error number
726 *
727 * Important: This image activator is byte order neutral.
728 *
729 * Note: A return value other than -1 indicates subsequent image
730 * activators should not be given the opportunity to attempt
731 * to activate the image.
732 *
733 * If we find an encapsulated binary, we make no assertions
734 * about its validity; instead, we leave that up to a rescan
735 * for an activator to claim it, and, if it is claimed by one,
736 * that activator is responsible for determining validity.
737 */
738 static int
exec_fat_imgact(struct image_params * imgp)739 exec_fat_imgact(struct image_params *imgp)
740 {
741 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
742 kauth_cred_t cred = kauth_cred_proc_ref(p);
743 struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
744 struct _posix_spawnattr *psa = NULL;
745 struct fat_arch fat_arch;
746 int resid, error;
747 load_return_t lret;
748
749 if (imgp->ip_origcputype != 0) {
750 /* Fat header previously matched, don't allow another fat file inside */
751 error = -1; /* not claimed */
752 goto bad;
753 }
754
755 /* Make sure it's a fat binary */
756 if (OSSwapBigToHostInt32(fat_header->magic) != FAT_MAGIC) {
757 error = -1; /* not claimed */
758 goto bad;
759 }
760
761 /* imgp->ip_vdata has PAGE_SIZE, zerofilled if the file is smaller */
762 lret = fatfile_validate_fatarches((vm_offset_t)fat_header, PAGE_SIZE,
763 (off_t)imgp->ip_vattr->va_data_size);
764 if (lret != LOAD_SUCCESS) {
765 error = load_return_to_errno(lret);
766 goto bad;
767 }
768
769 /* If posix_spawn binprefs exist, respect those prefs. */
770 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
771 if (psa != NULL && psa->psa_binprefs[0] != 0) {
772 uint32_t pr = 0;
773
774 /* Check each preference listed against all arches in header */
775 for (pr = 0; pr < NBINPREFS; pr++) {
776 cpu_type_t pref = psa->psa_binprefs[pr];
777 cpu_type_t subpref = psa->psa_subcpuprefs[pr];
778
779 if (pref == 0) {
780 /* No suitable arch in the pref list */
781 error = EBADARCH;
782 goto bad;
783 }
784
785 if (pref == CPU_TYPE_ANY) {
786 /* Fall through to regular grading */
787 goto regular_grading;
788 }
789
790 lret = fatfile_getbestarch_for_cputype(pref,
791 subpref,
792 (vm_offset_t)fat_header,
793 PAGE_SIZE,
794 imgp,
795 &fat_arch);
796 if (lret == LOAD_SUCCESS) {
797 goto use_arch;
798 }
799 }
800
801 /* Requested binary preference was not honored */
802 error = EBADEXEC;
803 goto bad;
804 }
805
806 regular_grading:
807 /* Look up our preferred architecture in the fat file. */
808 lret = fatfile_getbestarch((vm_offset_t)fat_header,
809 PAGE_SIZE,
810 imgp,
811 &fat_arch,
812 (p->p_flag & P_AFFINITY) != 0);
813 if (lret != LOAD_SUCCESS) {
814 error = load_return_to_errno(lret);
815 goto bad;
816 }
817
818 use_arch:
819 /* Read the Mach-O header out of fat_arch */
820 error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
821 PAGE_SIZE, fat_arch.offset,
822 UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
823 cred, &resid, p);
824 if (error) {
825 goto bad;
826 }
827
828 if (resid) {
829 memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
830 }
831
832 /* Success. Indicate we have identified an encapsulated binary */
833 error = -2;
834 imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
835 imgp->ip_arch_size = (user_size_t)fat_arch.size;
836 imgp->ip_origcputype = fat_arch.cputype;
837 imgp->ip_origcpusubtype = fat_arch.cpusubtype;
838
839 bad:
840 kauth_cred_unref(&cred);
841 return error;
842 }
843
844 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)845 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
846 {
847 int ret;
848
849 task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0);
850 task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
851 if (result->is_64bit_addr) {
852 OSBitOrAtomic(P_LP64, &p->p_flag);
853 get_bsdthread_info(thread)->uu_flag |= UT_LP64;
854 } else {
855 OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
856 get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
857 }
858 task_set_mach_header_address(task, result->mach_header);
859
860 ret = thread_state_initialize(thread);
861 if (ret != KERN_SUCCESS) {
862 return ret;
863 }
864
865 if (result->threadstate) {
866 uint32_t *ts = result->threadstate;
867 uint32_t total_size = (uint32_t)result->threadstate_sz;
868
869 while (total_size > 0) {
870 uint32_t flavor = *ts++;
871 uint32_t size = *ts++;
872
873 ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
874 if (ret) {
875 return ret;
876 }
877 ts += size;
878 total_size -= (size + 2) * sizeof(uint32_t);
879 }
880 }
881
882 thread_setentrypoint(thread, result->entry_point);
883
884 return KERN_SUCCESS;
885 }
886
887
888 void
set_proc_name(struct image_params * imgp,proc_t p)889 set_proc_name(struct image_params *imgp, proc_t p)
890 {
891 int p_name_len = sizeof(p->p_name) - 1;
892
893 if (imgp->ip_ndp->ni_cnd.cn_namelen > p_name_len) {
894 imgp->ip_ndp->ni_cnd.cn_namelen = p_name_len;
895 }
896
897 bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name,
898 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
899 p->p_name[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
900
901 if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN) {
902 imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
903 }
904
905 bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
906 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
907 p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
908 }
909
910 #if __has_feature(ptrauth_calls)
911 /**
912 * Returns a team ID string that may be used to assign a shared region.
913 *
914 * Platform binaries do not have team IDs and will return NULL. Non-platform
915 * binaries without a team ID will be assigned an artificial team ID of ""
916 * (empty string) so that they will not be assigned to the default shared
917 * region.
918 *
919 * @param imgp image parameter block
920 * @return NULL if this is a platform binary, or an appropriate team ID string
921 * otherwise
922 */
923 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)924 get_teamid_for_shared_region(struct image_params *imgp)
925 {
926 assert(imgp->ip_vp != NULL);
927
928 const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
929 if (ret) {
930 return ret;
931 }
932
933 struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
934 if (csblob_get_platform_binary(blob)) {
935 return NULL;
936 } else {
937 static const char *NO_TEAM_ID = "";
938 return NO_TEAM_ID;
939 }
940 }
941
942 /**
943 * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
944 *
945 * @param cpusubtype Mach-O style CPU subtype
946 * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
947 */
948 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)949 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
950 {
951 return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
952 CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
953 }
954
955 #endif /* __has_feature(ptrauth_calls) */
956
957 /**
958 * Returns whether a type/subtype slice matches the requested
959 * type/subtype.
960 *
961 * @param mask Bits to mask from the requested/tested cpu type
962 * @param req_cpu Requested cpu type
963 * @param req_subcpu Requested cpu subtype
964 * @param test_cpu Tested slice cpu type
965 * @param test_subcpu Tested slice cpu subtype
966 */
967 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)968 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
969 cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
970 cpu_subtype_t test_subcpu)
971 {
972 if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
973 return FALSE;
974 }
975
976 test_subcpu &= ~CPU_SUBTYPE_MASK;
977 req_subcpu &= ~CPU_SUBTYPE_MASK;
978
979 if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
980 return FALSE;
981 }
982
983 return TRUE;
984 }
985
986
987 /*
988 * exec_mach_imgact
989 *
990 * Image activator for mach-o 1.0 binaries.
991 *
992 * Parameters; struct image_params * image parameter block
993 *
994 * Returns: -1 not a fat binary (keep looking)
995 * -2 Success: encapsulated binary: reread
996 * >0 Failure: error number
997 * EBADARCH Mach-o binary, but with an unrecognized
998 * architecture
999 * ENOMEM No memory for child process after -
1000 * can only happen after vfork()
1001 *
1002 * Important: This image activator is NOT byte order neutral.
1003 *
1004 * Note: A return value other than -1 indicates subsequent image
1005 * activators should not be given the opportunity to attempt
1006 * to activate the image.
1007 */
1008 static int
exec_mach_imgact(struct image_params * imgp)1009 exec_mach_imgact(struct image_params *imgp)
1010 {
1011 struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1012 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
1013 int error = 0;
1014 task_t task;
1015 task_t new_task = NULL; /* protected by vfexec */
1016 thread_t thread;
1017 struct uthread *uthread;
1018 vm_map_t old_map = VM_MAP_NULL;
1019 vm_map_t map = VM_MAP_NULL;
1020 load_return_t lret;
1021 load_result_t load_result = {};
1022 struct _posix_spawnattr *psa = NULL;
1023 int spawn = (imgp->ip_flags & IMGPF_SPAWN);
1024 const int vfexec = 0;
1025 int exec = (imgp->ip_flags & IMGPF_EXEC);
1026 os_reason_t exec_failure_reason = OS_REASON_NULL;
1027 boolean_t reslide = FALSE;
1028
1029 /*
1030 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1031 * is a reserved field on the end, so for the most part, we can
1032 * treat them as if they were identical. Reverse-endian Mach-O
1033 * binaries are recognized but not compatible.
1034 */
1035 if ((mach_header->magic == MH_CIGAM) ||
1036 (mach_header->magic == MH_CIGAM_64)) {
1037 error = EBADARCH;
1038 goto bad;
1039 }
1040
1041 if ((mach_header->magic != MH_MAGIC) &&
1042 (mach_header->magic != MH_MAGIC_64)) {
1043 error = -1;
1044 goto bad;
1045 }
1046
1047 if (mach_header->filetype != MH_EXECUTE) {
1048 error = -1;
1049 goto bad;
1050 }
1051
1052 if (imgp->ip_origcputype != 0) {
1053 /* Fat header previously had an idea about this thin file */
1054 if (imgp->ip_origcputype != mach_header->cputype ||
1055 imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1056 error = EBADARCH;
1057 goto bad;
1058 }
1059 } else {
1060 imgp->ip_origcputype = mach_header->cputype;
1061 imgp->ip_origcpusubtype = mach_header->cpusubtype;
1062 }
1063
1064 task = current_task();
1065 thread = current_thread();
1066 uthread = get_bsdthread_info(thread);
1067
1068 if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1069 imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1070 }
1071
1072
1073 /* If posix_spawn binprefs exist, respect those prefs. */
1074 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1075 if (psa != NULL && psa->psa_binprefs[0] != 0) {
1076 int pr = 0;
1077 for (pr = 0; pr < NBINPREFS; pr++) {
1078 cpu_type_t pref = psa->psa_binprefs[pr];
1079 cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1080
1081 if (pref == 0) {
1082 /* No suitable arch in the pref list */
1083 error = EBADARCH;
1084 goto bad;
1085 }
1086
1087 if (pref == CPU_TYPE_ANY) {
1088 /* Jump to regular grading */
1089 goto grade;
1090 }
1091
1092 if (binary_match(CPU_ARCH_MASK, pref, subpref,
1093 imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1094 goto grade;
1095 }
1096 }
1097 error = EBADARCH;
1098 goto bad;
1099 }
1100 grade:
1101 if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1102 imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1103 error = EBADARCH;
1104 goto bad;
1105 }
1106
1107 if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1108 imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1109 #if __x86_64__
1110 const char *excpath;
1111 error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1112 os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1113 #endif
1114 error = EBADARCH;
1115 goto bad;
1116 }
1117
1118 #if defined(HAS_APPLE_PAC)
1119 assert(mach_header->cputype == CPU_TYPE_ARM64
1120 );
1121
1122 if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1123 arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1124 ) {
1125 imgp->ip_flags &= ~IMGPF_NOJOP;
1126 } else {
1127 imgp->ip_flags |= IMGPF_NOJOP;
1128 }
1129 #endif
1130
1131 /* Copy in arguments/environment from the old process */
1132 error = exec_extract_strings(imgp);
1133 if (error) {
1134 goto bad;
1135 }
1136
1137 AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1138 imgp->ip_endargv - imgp->ip_startargv);
1139 AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1140 imgp->ip_endenvv - imgp->ip_endargv);
1141
1142
1143
1144 /* reset local idea of thread, uthread, task */
1145 thread = imgp->ip_new_thread;
1146 uthread = get_bsdthread_info(thread);
1147 task = new_task = get_threadtask(thread);
1148
1149 /*
1150 * Load the Mach-O file.
1151 *
1152 * NOTE: An error after this point indicates we have potentially
1153 * destroyed or overwritten some process state while attempting an
1154 * execve() following a vfork(), which is an unrecoverable condition.
1155 * We send the new process an immediate SIGKILL to avoid it executing
1156 * any instructions in the mutated address space. For true spawns,
1157 * this is not the case, and "too late" is still not too late to
1158 * return an error code to the parent process.
1159 */
1160
1161 /*
1162 * Actually load the image file we previously decided to load.
1163 */
1164 lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1165 if (lret != LOAD_SUCCESS) {
1166 error = load_return_to_errno(lret);
1167
1168 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1169 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1170 if (lret == LOAD_BADMACHO_UPX) {
1171 set_proc_name(imgp, p);
1172 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1173 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1174 } else {
1175 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1176
1177 if (bootarg_execfailurereports) {
1178 set_proc_name(imgp, p);
1179 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1180 }
1181 }
1182
1183 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1184
1185 goto badtoolate;
1186 }
1187
1188 #ifndef KASAN
1189 /*
1190 * Security: zone sanity checks on fresh boot or initproc re-exec.
1191 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1192 * which means here is the earliest point we can assert on empty service port label zone,
1193 * after load_machfile() above terminates old launchd's IPC space.
1194 *
1195 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1196 * under quarantine.
1197 */
1198 if (task_pid(task) == 1) {
1199 assert(get_bsdtask_info(task) == initproc);
1200 zone_userspace_reboot_checks();
1201 }
1202 #endif
1203
1204 proc_lock(p);
1205 {
1206 p->p_cputype = imgp->ip_origcputype;
1207 p->p_cpusubtype = imgp->ip_origcpusubtype;
1208 }
1209 proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1210 vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1211 vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1212 vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1213 #if XNU_TARGET_OS_OSX
1214 if (proc_platform(p) == PLATFORM_IOS) {
1215 assert(vm_map_is_alien(map));
1216 } else {
1217 assert(!vm_map_is_alien(map));
1218 }
1219 #endif /* XNU_TARGET_OS_OSX */
1220 proc_unlock(p);
1221
1222 /*
1223 * Set code-signing flags if this binary is signed, or if parent has
1224 * requested them on exec.
1225 */
1226 if (load_result.csflags & CS_VALID) {
1227 imgp->ip_csflags |= load_result.csflags &
1228 (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1229 CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1230 CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1231 CS_ENTITLEMENT_FLAGS |
1232 CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1233 } else {
1234 imgp->ip_csflags &= ~CS_VALID;
1235 }
1236
1237 if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1238 imgp->ip_csflags |= CS_HARD;
1239 }
1240 if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1241 imgp->ip_csflags |= CS_KILL;
1242 }
1243 if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1244 imgp->ip_csflags |= CS_ENFORCEMENT;
1245 }
1246 if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1247 if (proc_getcsflags(p) & CS_INSTALLER) {
1248 imgp->ip_csflags |= CS_INSTALLER;
1249 }
1250 if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1251 imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1252 }
1253 if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1254 imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1255 }
1256 }
1257
1258 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1259 /*
1260 * ptrauth version 0 is a preview ABI. Developers can opt into running
1261 * their own arm64e binaries for local testing, with the understanding
1262 * that future OSes may break ABI.
1263 */
1264 if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1265 CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1266 !load_result.platform_binary &&
1267 !bootarg_arm64e_preview_abi) {
1268 static bool logged_once = false;
1269 set_proc_name(imgp, p);
1270
1271 printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1272 if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1273 printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1274 }
1275
1276 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1277 if (bootarg_execfailurereports) {
1278 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1279 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1280 }
1281 goto badtoolate;
1282 }
1283
1284 if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1285 imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1286 load_result.platform_binary &&
1287 (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1288 set_proc_name(imgp, p);
1289 printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
1290 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1291 if (bootarg_execfailurereports) {
1292 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1293 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1294 }
1295 goto badtoolate;
1296 }
1297 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1298
1299
1300 /*
1301 * Set up the shared cache region in the new process.
1302 *
1303 * Normally there is a single shared region per architecture.
1304 * However on systems with Pointer Authentication, we can create
1305 * multiple shared caches with the amount of sharing determined
1306 * by team-id or entitlement. Inherited shared region IDs are used
1307 * for system processes that need to match and be able to inspect
1308 * a pre-existing task.
1309 */
1310 int cpu_subtype = 0; /* all cpu_subtypes use the same shared region */
1311 #if __has_feature(ptrauth_calls)
1312 char *shared_region_id = NULL;
1313 size_t len;
1314 char *base;
1315 const char *cbase;
1316 #define TEAM_ID_PREFIX "T-"
1317 #define ENTITLE_PREFIX "E-"
1318 #define SR_PREFIX_LEN 2
1319 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1320
1321 if (cpu_type() == CPU_TYPE_ARM64 &&
1322 arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1323 (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1324 assertf(p->p_cputype == CPU_TYPE_ARM64,
1325 "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1326 p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1327
1328 /*
1329 * arm64e uses pointer authentication, so request a separate
1330 * shared region for this CPU subtype.
1331 */
1332 cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1333
1334 /*
1335 * Determine which shared cache to select based on being told,
1336 * matching a team-id or matching an entitlement.
1337 */
1338 if (imgp->ip_inherited_shared_region_id) {
1339 len = strlen(imgp->ip_inherited_shared_region_id);
1340 shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1341 memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1342 } else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1343 len = strlen(cbase);
1344 if (vm_shared_region_per_team_id) {
1345 shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1346 Z_WAITOK | Z_NOFAIL);
1347 memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1348 memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1349 }
1350 } else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1351 (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1352 len = strlen(base);
1353 if (vm_shared_region_by_entitlement) {
1354 shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1355 Z_WAITOK | Z_NOFAIL);
1356 memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1357 memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1358 }
1359 /* Discard the copy of the entitlement */
1360 kfree_data(base, len + 1);
1361 }
1362 }
1363
1364 if (imgp->ip_flags & IMGPF_RESLIDE) {
1365 reslide = TRUE;
1366 }
1367
1368 /* use "" as the default shared_region_id */
1369 if (shared_region_id == NULL) {
1370 shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1371 }
1372
1373 /* ensure there's a unique pointer signing key for this shared_region_id */
1374 shared_region_key_alloc(shared_region_id,
1375 imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1376 task_set_shared_region_id(task, shared_region_id);
1377 shared_region_id = NULL;
1378 #endif /* __has_feature(ptrauth_calls) */
1379
1380 int cputype = cpu_type();
1381 vm_map_exec(map, task, load_result.is_64bit_addr,
1382 (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide, (imgp->ip_flags & IMGPF_DRIVER) != 0 && vm_enable_driverkit_shared_region);
1383
1384 /*
1385 * Close file descriptors which specify close-on-exec.
1386 */
1387 fdt_exec(p, psa != NULL ? psa->psa_flags : 0);
1388
1389 /*
1390 * deal with set[ug]id.
1391 */
1392 error = exec_handle_sugid(imgp);
1393 if (error) {
1394 vm_map_deallocate(map);
1395
1396 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1397 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1398
1399 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1400 if (bootarg_execfailurereports) {
1401 set_proc_name(imgp, p);
1402 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1403 }
1404
1405 goto badtoolate;
1406 }
1407
1408 /*
1409 * Commit to new map.
1410 *
1411 * Swap the new map for the old for target task, which consumes
1412 * our new map reference but each leaves us responsible for the
1413 * old_map reference. That lets us get off the pmap associated
1414 * with it, and then we can release it.
1415 *
1416 * The map needs to be set on the target task which is different
1417 * than current task, thus swap_task_map is used instead of
1418 * vm_map_switch.
1419 */
1420 old_map = swap_task_map(task, thread, map);
1421 vm_map_deallocate(old_map);
1422 old_map = NULL;
1423
1424 lret = activate_exec_state(task, p, thread, &load_result);
1425 if (lret != KERN_SUCCESS) {
1426 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1427 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1428
1429 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1430 if (bootarg_execfailurereports) {
1431 set_proc_name(imgp, p);
1432 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1433 }
1434
1435 goto badtoolate;
1436 }
1437
1438 /*
1439 * deal with voucher on exec-calling thread.
1440 */
1441 if (imgp->ip_new_thread == NULL) {
1442 thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1443 }
1444
1445 /* Make sure we won't interrupt ourself signalling a partial process */
1446 if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1447 psignal(p, SIGTRAP);
1448 }
1449
1450 if (load_result.unixproc &&
1451 create_unix_stack(get_task_map(task),
1452 &load_result,
1453 p) != KERN_SUCCESS) {
1454 error = load_return_to_errno(LOAD_NOSPACE);
1455
1456 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1457 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1458
1459 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1460 if (bootarg_execfailurereports) {
1461 set_proc_name(imgp, p);
1462 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1463 }
1464
1465 goto badtoolate;
1466 }
1467
1468 /*
1469 * The load result will have already been munged by AMFI to include the
1470 * platform binary flag if boot-args dictated it (AMFI will mark anything
1471 * that doesn't go through the upcall path as a platform binary if its
1472 * enforcement is disabled).
1473 */
1474 if (load_result.platform_binary) {
1475 if (cs_debug) {
1476 printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1477 }
1478
1479 /*
1480 * We must use 'task' here because the proc's task has not yet been
1481 * switched to the new one.
1482 */
1483 task_set_platform_binary(task, TRUE);
1484 } else {
1485 if (cs_debug) {
1486 printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1487 }
1488
1489 task_set_platform_binary(task, FALSE);
1490 }
1491
1492 /*
1493 * Set starting EXC_GUARD and control port behavior for task now that
1494 * platform is set. Use the name directly from imgp since we haven't
1495 * set_proc_name() yet. Also make control port for the task and main thread
1496 * immovable/pinned based on task's option.
1497 *
1498 * Must happen before main thread port copyout in exc_add_apple_strings.
1499 */
1500 task_set_exc_guard_ctrl_port_default(task, thread,
1501 imgp->ip_ndp->ni_cnd.cn_nameptr,
1502 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1503 proc_is_simulated(p),
1504 load_result.ip_platform,
1505 load_result.lr_sdk);
1506
1507 error = exec_add_apple_strings(imgp, &load_result); /* copies out main thread port */
1508
1509 if (error) {
1510 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1511 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
1512
1513 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
1514 if (bootarg_execfailurereports) {
1515 set_proc_name(imgp, p);
1516 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1517 }
1518 goto badtoolate;
1519 }
1520
1521 /* Switch to target task's map to copy out strings */
1522 old_map = vm_map_switch(get_task_map(task));
1523
1524 if (load_result.unixproc) {
1525 user_addr_t ap;
1526
1527 /*
1528 * Copy the strings area out into the new process address
1529 * space.
1530 */
1531 ap = p->user_stack;
1532 error = exec_copyout_strings(imgp, &ap);
1533 if (error) {
1534 vm_map_switch(old_map);
1535
1536 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1537 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
1538
1539 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
1540 if (bootarg_execfailurereports) {
1541 set_proc_name(imgp, p);
1542 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1543 }
1544 goto badtoolate;
1545 }
1546 /* Set the stack */
1547 thread_setuserstack(thread, ap);
1548 }
1549
1550 if (load_result.dynlinker || load_result.is_cambria) {
1551 user_addr_t ap;
1552 int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
1553
1554 /* Adjust the stack */
1555 ap = thread_adjuserstack(thread, -new_ptr_size);
1556 error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
1557
1558 if (error) {
1559 vm_map_switch(old_map);
1560
1561 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1562 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
1563
1564 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
1565 if (bootarg_execfailurereports) {
1566 set_proc_name(imgp, p);
1567 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1568 }
1569 goto badtoolate;
1570 }
1571 task_set_dyld_info(task, load_result.all_image_info_addr,
1572 load_result.all_image_info_size);
1573 }
1574
1575
1576 /* Avoid immediate VM faults back into kernel */
1577 exec_prefault_data(p, imgp, &load_result);
1578
1579 vm_map_switch(old_map);
1580
1581 /*
1582 * Reset signal state.
1583 */
1584 execsigs(p, thread);
1585
1586 /*
1587 * need to cancel async IO requests that can be cancelled and wait for those
1588 * already active. MAY BLOCK!
1589 */
1590 _aio_exec( p );
1591
1592 #if SYSV_SHM
1593 /* FIXME: Till vmspace inherit is fixed: */
1594 if (!vfexec && p->vm_shm) {
1595 shmexec(p);
1596 }
1597 #endif
1598 #if SYSV_SEM
1599 /* Clean up the semaphores */
1600 semexit(p);
1601 #endif
1602
1603 /*
1604 * Remember file name for accounting.
1605 */
1606 p->p_acflag &= ~AFORK;
1607
1608 set_proc_name(imgp, p);
1609
1610 #if CONFIG_SECLUDED_MEMORY
1611 if (secluded_for_apps &&
1612 load_result.platform_binary) {
1613 if (strncmp(p->p_name,
1614 "Camera",
1615 sizeof(p->p_name)) == 0) {
1616 task_set_could_use_secluded_mem(task, TRUE);
1617 } else {
1618 task_set_could_use_secluded_mem(task, FALSE);
1619 }
1620 if (strncmp(p->p_name,
1621 "mediaserverd",
1622 sizeof(p->p_name)) == 0) {
1623 task_set_could_also_use_secluded_mem(task, TRUE);
1624 }
1625 }
1626 #endif /* CONFIG_SECLUDED_MEMORY */
1627
1628 #if __arm64__
1629 if (load_result.legacy_footprint) {
1630 task_set_legacy_footprint(task);
1631 }
1632 #endif /* __arm64__ */
1633
1634 pal_dbg_set_task_name(task);
1635
1636 #if DEVELOPMENT || DEBUG
1637 /*
1638 * Update the pid an proc name for importance base if any
1639 */
1640 task_importance_update_owner_info(task);
1641 #endif
1642
1643 proc_setexecutableuuid(p, &load_result.uuid[0]);
1644
1645 #if CONFIG_DTRACE
1646 dtrace_proc_exec(p);
1647 #endif
1648
1649 if (kdebug_enable) {
1650 long args[4] = {};
1651
1652 uintptr_t fsid = 0, fileid = 0;
1653 if (imgp->ip_vattr) {
1654 uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
1655 fsid = (uintptr_t)fsid64;
1656 fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
1657 // check for (unexpected) overflow and trace zero in that case
1658 if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
1659 fsid = fileid = 0;
1660 }
1661 }
1662 KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
1663 (uintptr_t)thread_tid(thread));
1664
1665 /*
1666 * Collect the pathname for tracing
1667 */
1668 kdbg_trace_string(p, &args[0], &args[1], &args[2], &args[3]);
1669 KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
1670 args[2], args[3], (uintptr_t)thread_tid(thread));
1671 }
1672
1673
1674 /*
1675 * If posix_spawned with the START_SUSPENDED flag, stop the
1676 * process before it runs.
1677 */
1678 if (imgp->ip_px_sa != NULL) {
1679 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1680 if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
1681 proc_lock(p);
1682 p->p_stat = SSTOP;
1683 proc_unlock(p);
1684 (void) task_suspend_internal(task);
1685 }
1686 }
1687
1688 /*
1689 * mark as execed
1690 */
1691 OSBitOrAtomic(P_EXEC, &p->p_flag);
1692 proc_resetregister(p);
1693 if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
1694 proc_lock(p);
1695 p->p_lflag &= ~P_LPPWAIT;
1696 proc_unlock(p);
1697 wakeup((caddr_t)p->p_pptr);
1698 }
1699
1700
1701 goto done;
1702
1703 badtoolate:
1704 /* Don't allow child process to execute any instructions */
1705 if (!spawn) {
1706 {
1707 assert(exec_failure_reason != OS_REASON_NULL);
1708 psignal_with_reason(p, SIGKILL, exec_failure_reason);
1709 exec_failure_reason = OS_REASON_NULL;
1710
1711 if (exec) {
1712 /* Terminate the exec copy task */
1713 task_terminate_internal(task);
1714 }
1715 }
1716
1717 /* We can't stop this system call at this point, so just pretend we succeeded */
1718 error = 0;
1719 } else {
1720 os_reason_free(exec_failure_reason);
1721 exec_failure_reason = OS_REASON_NULL;
1722 }
1723
1724 done:
1725 if (load_result.threadstate) {
1726 kfree_data(load_result.threadstate, load_result.threadstate_sz);
1727 load_result.threadstate = NULL;
1728 }
1729
1730 bad:
1731 /* If we hit this, we likely would have leaked an exit reason */
1732 assert(exec_failure_reason == OS_REASON_NULL);
1733 return error;
1734 }
1735
1736
1737
1738
1739 /*
1740 * Our image activator table; this is the table of the image types we are
1741 * capable of loading. We list them in order of preference to ensure the
1742 * fastest image load speed.
1743 *
1744 * XXX hardcoded, for now; should use linker sets
1745 */
1746 struct execsw {
1747 int(*const ex_imgact)(struct image_params *);
1748 const char *ex_name;
1749 }const execsw[] = {
1750 { exec_mach_imgact, "Mach-o Binary" },
1751 { exec_fat_imgact, "Fat Binary" },
1752 { exec_shell_imgact, "Interpreter Script" },
1753 { NULL, NULL}
1754 };
1755
1756
1757 /*
1758 * exec_activate_image
1759 *
1760 * Description: Iterate through the available image activators, and activate
1761 * the image associated with the imgp structure. We start with
1762 * the activator for Mach-o binaries followed by that for Fat binaries
1763 * for Interpreter scripts.
1764 *
1765 * Parameters: struct image_params * Image parameter block
1766 *
1767 * Returns: 0 Success
1768 * ENOEXEC No activator for image.
1769 * EBADEXEC The executable is corrupt/unknown
1770 * execargs_alloc:EINVAL Invalid argument
1771 * execargs_alloc:EACCES Permission denied
1772 * execargs_alloc:EINTR Interrupted function
1773 * execargs_alloc:ENOMEM Not enough space
1774 * exec_save_path:EFAULT Bad address
1775 * exec_save_path:ENAMETOOLONG Filename too long
1776 * exec_check_permissions:EACCES Permission denied
1777 * exec_check_permissions:ENOEXEC Executable file format error
1778 * exec_check_permissions:ETXTBSY Text file busy [misuse of error code]
1779 * exec_check_permissions:???
1780 * namei:???
1781 * vn_rdwr:??? [anything vn_rdwr can return]
1782 * <ex_imgact>:??? [anything an imgact can return]
1783 * EDEADLK Process is being terminated
1784 */
1785 static int
exec_activate_image(struct image_params * imgp)1786 exec_activate_image(struct image_params *imgp)
1787 {
1788 struct nameidata *ndp = NULL;
1789 const char *excpath;
1790 int error;
1791 int resid;
1792 int once = 1; /* save SGUID-ness for interpreted files */
1793 int i;
1794 int itercount = 0;
1795 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
1796
1797 error = execargs_alloc(imgp);
1798 if (error) {
1799 goto bad_notrans;
1800 }
1801
1802 error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1803 if (error) {
1804 goto bad_notrans;
1805 }
1806
1807 /* Use excpath, which contains the copyin-ed exec path */
1808 DTRACE_PROC1(exec, uintptr_t, excpath);
1809
1810 ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1811
1812 NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
1813 UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
1814
1815 again:
1816 error = namei(ndp);
1817 if (error) {
1818 if (error == ERESTART) {
1819 error = EINTR;
1820 }
1821 goto bad_notrans;
1822 }
1823 imgp->ip_ndp = ndp; /* successful namei(); call nameidone() later */
1824 imgp->ip_vp = ndp->ni_vp; /* if set, need to vnode_put() at some point */
1825
1826 /*
1827 * Before we start the transition from binary A to binary B, make
1828 * sure another thread hasn't started exiting the process. We grab
1829 * the proc lock to check p_lflag initially, and the transition
1830 * mechanism ensures that the value doesn't change after we release
1831 * the lock.
1832 */
1833 proc_lock(p);
1834 if (p->p_lflag & P_LEXIT) {
1835 error = EDEADLK;
1836 proc_unlock(p);
1837 goto bad_notrans;
1838 }
1839 error = proc_transstart(p, 1, 0);
1840 proc_unlock(p);
1841 if (error) {
1842 goto bad_notrans;
1843 }
1844
1845 error = exec_check_permissions(imgp);
1846 if (error) {
1847 goto bad;
1848 }
1849
1850 /* Copy; avoid invocation of an interpreter overwriting the original */
1851 if (once) {
1852 once = 0;
1853 *imgp->ip_origvattr = *imgp->ip_vattr;
1854 }
1855
1856 error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
1857 UIO_SYSSPACE, IO_NODELOCKED,
1858 vfs_context_ucred(imgp->ip_vfs_context),
1859 &resid, vfs_context_proc(imgp->ip_vfs_context));
1860 if (error) {
1861 goto bad;
1862 }
1863
1864 if (resid) {
1865 memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
1866 }
1867
1868 encapsulated_binary:
1869 /* Limit the number of iterations we will attempt on each binary */
1870 if (++itercount > EAI_ITERLIMIT) {
1871 error = EBADEXEC;
1872 goto bad;
1873 }
1874 error = -1;
1875 for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
1876 error = (*execsw[i].ex_imgact)(imgp);
1877
1878 switch (error) {
1879 /* case -1: not claimed: continue */
1880 case -2: /* Encapsulated binary, imgp->ip_XXX set for next iteration */
1881 goto encapsulated_binary;
1882
1883 case -3: /* Interpreter */
1884 #if CONFIG_MACF
1885 /*
1886 * Copy the script label for later use. Note that
1887 * the label can be different when the script is
1888 * actually read by the interpreter.
1889 */
1890 if (imgp->ip_scriptlabelp) {
1891 mac_vnode_label_free(imgp->ip_scriptlabelp);
1892 imgp->ip_scriptlabelp = NULL;
1893 }
1894 imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
1895 if (imgp->ip_scriptlabelp == NULL) {
1896 error = ENOMEM;
1897 break;
1898 }
1899 mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
1900 imgp->ip_scriptlabelp);
1901
1902 /*
1903 * Take a ref of the script vnode for later use.
1904 */
1905 if (imgp->ip_scriptvp) {
1906 vnode_put(imgp->ip_scriptvp);
1907 imgp->ip_scriptvp = NULLVP;
1908 }
1909 if (vnode_getwithref(imgp->ip_vp) == 0) {
1910 imgp->ip_scriptvp = imgp->ip_vp;
1911 }
1912 #endif
1913
1914 nameidone(ndp);
1915
1916 vnode_put(imgp->ip_vp);
1917 imgp->ip_vp = NULL; /* already put */
1918 imgp->ip_ndp = NULL; /* already nameidone */
1919
1920 /* Use excpath, which exec_shell_imgact reset to the interpreter */
1921 NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
1922 UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
1923
1924 proc_transend(p, 0);
1925 goto again;
1926
1927 default:
1928 break;
1929 }
1930 }
1931
1932 if (error == -1) {
1933 error = ENOEXEC;
1934 } else if (error == 0) {
1935 if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
1936 AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
1937 }
1938
1939 /*
1940 * Call out to allow 3rd party notification of exec.
1941 * Ignore result of kauth_authorize_fileop call.
1942 */
1943 if (kauth_authorize_fileop_has_listeners()) {
1944 kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
1945 KAUTH_FILEOP_EXEC,
1946 (uintptr_t)ndp->ni_vp, 0);
1947 }
1948 }
1949 bad:
1950 proc_transend(p, 0);
1951
1952 bad_notrans:
1953 if (imgp->ip_strings) {
1954 execargs_free(imgp);
1955 }
1956 if (imgp->ip_ndp) {
1957 nameidone(imgp->ip_ndp);
1958 }
1959 kfree_type(struct nameidata, ndp);
1960
1961 return error;
1962 }
1963
1964 /*
1965 * exec_validate_spawnattr_policy
1966 *
1967 * Description: Validates the entitlements required to set the apptype.
1968 *
1969 * Parameters: int psa_apptype posix spawn attribute apptype
1970 *
1971 * Returns: 0 Success
1972 * EPERM Failure
1973 */
1974 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)1975 exec_validate_spawnattr_policy(int psa_apptype)
1976 {
1977 if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
1978 int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
1979 if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
1980 if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
1981 return EPERM;
1982 }
1983 }
1984 }
1985
1986 return 0;
1987 }
1988
1989 /*
1990 * exec_handle_spawnattr_policy
1991 *
1992 * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
1993 *
1994 * Parameters: proc_t p process to apply attributes to
1995 * int psa_apptype posix spawn attribute apptype
1996 *
1997 * Returns: 0 Success
1998 */
1999 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)2000 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2001 task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2002 {
2003 int apptype = TASK_APPTYPE_NONE;
2004 int qos_clamp = THREAD_QOS_UNSPECIFIED;
2005 task_role_t role = TASK_UNSPECIFIED;
2006
2007 if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2008 int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2009
2010 switch (proctype) {
2011 case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2012 apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2013 break;
2014 case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2015 apptype = TASK_APPTYPE_DAEMON_STANDARD;
2016 break;
2017 case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2018 apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2019 break;
2020 case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2021 apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2022 break;
2023 case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2024 apptype = TASK_APPTYPE_APP_DEFAULT;
2025 break;
2026 case POSIX_SPAWN_PROC_TYPE_DRIVER:
2027 apptype = TASK_APPTYPE_DRIVER;
2028 break;
2029 default:
2030 apptype = TASK_APPTYPE_NONE;
2031 /* TODO: Should an invalid value here fail the spawn? */
2032 break;
2033 }
2034 }
2035
2036 if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2037 switch (psa_qos_clamp) {
2038 case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2039 qos_clamp = THREAD_QOS_UTILITY;
2040 break;
2041 case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2042 qos_clamp = THREAD_QOS_BACKGROUND;
2043 break;
2044 case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2045 qos_clamp = THREAD_QOS_MAINTENANCE;
2046 break;
2047 default:
2048 qos_clamp = THREAD_QOS_UNSPECIFIED;
2049 /* TODO: Should an invalid value here fail the spawn? */
2050 break;
2051 }
2052 }
2053
2054 if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2055 proc_darwin_role_to_task_role(psa_darwin_role, &role);
2056 }
2057
2058 if (apptype != TASK_APPTYPE_NONE ||
2059 qos_clamp != THREAD_QOS_UNSPECIFIED ||
2060 role != TASK_UNSPECIFIED ||
2061 port_actions->portwatch_count) {
2062 proc_set_task_spawnpolicy(p->task, thread, apptype, qos_clamp, role,
2063 port_actions->portwatch_array, port_actions->portwatch_count);
2064 }
2065
2066 if (port_actions->registered_count) {
2067 if (mach_ports_register(p->task, port_actions->registered_array,
2068 port_actions->registered_count)) {
2069 return EINVAL;
2070 }
2071 /* mach_ports_register() consumed the array */
2072 port_actions->registered_array = NULL;
2073 port_actions->registered_count = 0;
2074 }
2075
2076 return 0;
2077 }
2078
2079 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2080 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2081 {
2082 if (port_actions->portwatch_array) {
2083 for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2084 ipc_port_t port = NULL;
2085 if ((port = port_actions->portwatch_array[i]) != NULL) {
2086 ipc_port_release_send(port);
2087 }
2088 }
2089 kfree_type(ipc_port_t, port_actions->portwatch_count,
2090 port_actions->portwatch_array);
2091 }
2092
2093 if (port_actions->registered_array) {
2094 for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2095 ipc_port_t port = NULL;
2096 if ((port = port_actions->registered_array[i]) != NULL) {
2097 ipc_port_release_send(port);
2098 }
2099 }
2100 kfree_type(ipc_port_t, port_actions->registered_count,
2101 port_actions->registered_array);
2102 }
2103 }
2104
2105 /*
2106 * exec_handle_port_actions
2107 *
2108 * Description: Go through the _posix_port_actions_t contents,
2109 * calling task_set_special_port, task_set_exception_ports
2110 * and/or audit_session_spawnjoin for the current task.
2111 *
2112 * Parameters: struct image_params * Image parameter block
2113 *
2114 * Returns: 0 Success
2115 * EINVAL Failure
2116 * ENOTSUP Illegal posix_spawn attr flag was set
2117 */
2118 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2119 exec_handle_port_actions(struct image_params *imgp,
2120 struct exec_port_actions *actions)
2121 {
2122 _posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2123 #if CONFIG_AUDIT
2124 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2125 #endif
2126 _ps_port_action_t *act = NULL;
2127 task_t task = get_threadtask(imgp->ip_new_thread);
2128 ipc_port_t port = NULL;
2129 errno_t ret = 0;
2130 int i, portwatch_i = 0, registered_i = 0;
2131 kern_return_t kr;
2132 boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2133 boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2134 int ptrauth_task_port_count = 0;
2135
2136 for (i = 0; i < pacts->pspa_count; i++) {
2137 act = &pacts->pspa_actions[i];
2138
2139 switch (act->port_type) {
2140 case PSPA_SPECIAL:
2141 case PSPA_EXCEPTION:
2142 #if CONFIG_AUDIT
2143 case PSPA_AU_SESSION:
2144 #endif
2145 break;
2146 case PSPA_IMP_WATCHPORTS:
2147 if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
2148 ret = EINVAL;
2149 goto done;
2150 }
2151 break;
2152 case PSPA_REGISTERED_PORTS:
2153 if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
2154 ret = EINVAL;
2155 goto done;
2156 }
2157 break;
2158 case PSPA_PTRAUTH_TASK_PORT:
2159 if (++ptrauth_task_port_count > 1) {
2160 ret = EINVAL;
2161 goto done;
2162 }
2163 break;
2164 default:
2165 ret = EINVAL;
2166 goto done;
2167 }
2168 }
2169
2170 if (actions->portwatch_count) {
2171 if (in_exec && task_has_watchport_boost) {
2172 ret = EINVAL;
2173 goto done;
2174 }
2175 actions->portwatch_array = kalloc_type(ipc_port_t,
2176 actions->portwatch_count, Z_WAITOK | Z_ZERO);
2177 if (actions->portwatch_array == NULL) {
2178 ret = ENOMEM;
2179 goto done;
2180 }
2181 }
2182
2183 if (actions->registered_count) {
2184 actions->registered_array = kalloc_type(ipc_port_t,
2185 actions->registered_count, Z_WAITOK | Z_ZERO);
2186 if (actions->registered_array == NULL) {
2187 ret = ENOMEM;
2188 goto done;
2189 }
2190 }
2191
2192 for (i = 0; i < pacts->pspa_count; i++) {
2193 act = &pacts->pspa_actions[i];
2194
2195 if (MACH_PORT_VALID(act->new_port)) {
2196 kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2197 act->new_port, MACH_MSG_TYPE_COPY_SEND,
2198 (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2199
2200 if (kr != KERN_SUCCESS) {
2201 ret = EINVAL;
2202 goto done;
2203 }
2204 } else {
2205 /* it's NULL or DEAD */
2206 port = CAST_MACH_NAME_TO_PORT(act->new_port);
2207 }
2208
2209 switch (act->port_type) {
2210 case PSPA_SPECIAL:
2211 kr = task_set_special_port(task, act->which, port);
2212
2213 if (kr != KERN_SUCCESS) {
2214 ret = EINVAL;
2215 }
2216 break;
2217
2218 case PSPA_EXCEPTION:
2219 kr = task_set_exception_ports(task, act->mask, port,
2220 act->behavior, act->flavor);
2221 if (kr != KERN_SUCCESS) {
2222 ret = EINVAL;
2223 }
2224 break;
2225 #if CONFIG_AUDIT
2226 case PSPA_AU_SESSION:
2227 ret = audit_session_spawnjoin(p, task, port);
2228 if (ret) {
2229 /* audit_session_spawnjoin() has already dropped the reference in case of error. */
2230 goto done;
2231 }
2232
2233 break;
2234 #endif
2235 case PSPA_IMP_WATCHPORTS:
2236 if (actions->portwatch_array) {
2237 /* hold on to this till end of spawn */
2238 actions->portwatch_array[portwatch_i++] = port;
2239 } else {
2240 ipc_port_release_send(port);
2241 }
2242 break;
2243 case PSPA_REGISTERED_PORTS:
2244 /* hold on to this till end of spawn */
2245 actions->registered_array[registered_i++] = port;
2246 break;
2247
2248 case PSPA_PTRAUTH_TASK_PORT:
2249 #if defined(HAS_APPLE_PAC)
2250 {
2251 task_t ptr_auth_task = convert_port_to_task(port);
2252
2253 if (ptr_auth_task == TASK_NULL) {
2254 ret = EINVAL;
2255 break;
2256 }
2257
2258 imgp->ip_inherited_shared_region_id =
2259 task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
2260 &imgp->ip_inherited_jop_pid);
2261
2262 /* Deallocate task ref returned by convert_port_to_task */
2263 task_deallocate(ptr_auth_task);
2264 }
2265 #endif /* HAS_APPLE_PAC */
2266
2267 /* consume the port right in case of success */
2268 ipc_port_release_send(port);
2269 break;
2270 default:
2271 ret = EINVAL;
2272 break;
2273 }
2274
2275 if (ret) {
2276 /* action failed, so release port resources */
2277 ipc_port_release_send(port);
2278 break;
2279 }
2280 }
2281
2282 done:
2283 if (0 != ret) {
2284 DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2285 }
2286 return ret;
2287 }
2288
2289 /*
2290 * exec_handle_file_actions
2291 *
2292 * Description: Go through the _posix_file_actions_t contents applying the
2293 * open, close, and dup2 operations to the open file table for
2294 * the current process.
2295 *
2296 * Parameters: struct image_params * Image parameter block
2297 *
2298 * Returns: 0 Success
2299 * ???
2300 *
2301 * Note: Actions are applied in the order specified, with the credential
2302 * of the parent process. This is done to permit the parent
2303 * process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
2304 * the child following operations the child may in fact not be
2305 * normally permitted to perform.
2306 */
2307 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)2308 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
2309 {
2310 int error = 0;
2311 int action;
2312 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2313 _posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
2314 int ival[2]; /* dummy retval for system calls) */
2315 #if CONFIG_AUDIT
2316 struct uthread *uthread = current_uthread();
2317 #endif
2318
2319 for (action = 0; action < px_sfap->psfa_act_count; action++) {
2320 _psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2321
2322 switch (psfa->psfaa_type) {
2323 case PSFA_OPEN: {
2324 /*
2325 * Open is different, in that it requires the use of
2326 * a path argument, which is normally copied in from
2327 * user space; because of this, we have to support an
2328 * open from kernel space that passes an address space
2329 * context of UIO_SYSSPACE, and casts the address
2330 * argument to a user_addr_t.
2331 */
2332 struct vnode_attr *vap;
2333 struct nameidata *ndp;
2334 int mode = psfa->psfaa_openargs.psfao_mode;
2335 int origfd;
2336 struct {
2337 struct vnode_attr va;
2338 struct nameidata nd;
2339 } *__open_data;
2340
2341 __open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
2342 if (__open_data == NULL) {
2343 error = ENOMEM;
2344 break;
2345 }
2346
2347 vap = &__open_data->va;
2348 ndp = &__open_data->nd;
2349
2350 VATTR_INIT(vap);
2351 /* Mask off all but regular access permissions */
2352 mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
2353 VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
2354
2355 AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
2356
2357 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2358 CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
2359 imgp->ip_vfs_context);
2360
2361 error = open1(imgp->ip_vfs_context, ndp,
2362 psfa->psfaa_openargs.psfao_oflag,
2363 vap, NULL, NULL, &origfd);
2364
2365 kfree_type(typeof(*__open_data), __open_data);
2366
2367 AUDIT_SUBCALL_EXIT(uthread, error);
2368
2369 /*
2370 * If there's an error, or we get the right fd by
2371 * accident, then drop out here. This is easier than
2372 * reworking all the open code to preallocate fd
2373 * slots, and internally taking one as an argument.
2374 */
2375 if (error || origfd == psfa->psfaa_filedes) {
2376 break;
2377 }
2378
2379 /*
2380 * If we didn't fall out from an error, we ended up
2381 * with the wrong fd; so now we've got to try to dup2
2382 * it to the right one.
2383 */
2384 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2385 error = dup2(p, origfd, psfa->psfaa_filedes, ival);
2386 AUDIT_SUBCALL_EXIT(uthread, error);
2387 if (error) {
2388 break;
2389 }
2390
2391 /*
2392 * Finally, close the original fd.
2393 */
2394 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2395 error = close_nocancel(p, origfd);
2396 AUDIT_SUBCALL_EXIT(uthread, error);
2397 }
2398 break;
2399
2400 case PSFA_DUP2: {
2401 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2402 error = dup2(p, psfa->psfaa_filedes,
2403 psfa->psfaa_dup2args.psfad_newfiledes, ival);
2404 AUDIT_SUBCALL_EXIT(uthread, error);
2405 }
2406 break;
2407
2408 case PSFA_FILEPORT_DUP2: {
2409 ipc_port_t port;
2410 kern_return_t kr;
2411 int origfd;
2412
2413 if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
2414 error = EINVAL;
2415 break;
2416 }
2417
2418 kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2419 psfa->psfaa_fileport, MACH_MSG_TYPE_COPY_SEND,
2420 (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2421
2422 if (kr != KERN_SUCCESS) {
2423 error = EINVAL;
2424 break;
2425 }
2426
2427 error = fileport_makefd(p, port, 0, &origfd);
2428
2429 if (IPC_PORT_NULL != port) {
2430 ipc_port_release_send(port);
2431 }
2432
2433 if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
2434 break;
2435 }
2436
2437 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2438 error = dup2(p, origfd,
2439 psfa->psfaa_dup2args.psfad_newfiledes, ival);
2440 AUDIT_SUBCALL_EXIT(uthread, error);
2441 if (error) {
2442 break;
2443 }
2444
2445 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2446 error = close_nocancel(p, origfd);
2447 AUDIT_SUBCALL_EXIT(uthread, error);
2448 }
2449 break;
2450
2451 case PSFA_CLOSE: {
2452 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2453 error = close_nocancel(p, psfa->psfaa_filedes);
2454 AUDIT_SUBCALL_EXIT(uthread, error);
2455 }
2456 break;
2457
2458 case PSFA_INHERIT: {
2459 struct fileproc *fp;
2460
2461 /*
2462 * Check to see if the descriptor exists, and
2463 * ensure it's -not- marked as close-on-exec.
2464 *
2465 * Attempting to "inherit" a guarded fd will
2466 * result in a error.
2467 */
2468
2469 proc_fdlock(p);
2470 if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
2471 error = EBADF;
2472 } else if (fp->fp_guard_attrs) {
2473 error = fp_guard_exception(p, psfa->psfaa_filedes,
2474 fp, kGUARD_EXC_NOCLOEXEC);
2475 } else {
2476 fp->fp_flags &= ~FP_CLOEXEC;
2477 error = 0;
2478 }
2479 proc_fdunlock(p);
2480 }
2481 break;
2482
2483 case PSFA_CHDIR: {
2484 /*
2485 * Chdir is different, in that it requires the use of
2486 * a path argument, which is normally copied in from
2487 * user space; because of this, we have to support a
2488 * chdir from kernel space that passes an address space
2489 * context of UIO_SYSSPACE, and casts the address
2490 * argument to a user_addr_t.
2491 */
2492 struct nameidata *nd;
2493 nd = kalloc_type(struct nameidata,
2494 Z_WAITOK | Z_ZERO | Z_NOFAIL);
2495
2496 AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
2497 NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2498 CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
2499 imgp->ip_vfs_context);
2500
2501 error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
2502 kfree_type(struct nameidata, nd);
2503 AUDIT_SUBCALL_EXIT(uthread, error);
2504 }
2505 break;
2506
2507 case PSFA_FCHDIR: {
2508 struct fchdir_args fchdira;
2509
2510 fchdira.fd = psfa->psfaa_filedes;
2511
2512 AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
2513 error = fchdir(p, &fchdira, ival);
2514 AUDIT_SUBCALL_EXIT(uthread, error);
2515 }
2516 break;
2517
2518 default:
2519 error = EINVAL;
2520 break;
2521 }
2522
2523 /* All file actions failures are considered fatal, per POSIX */
2524
2525 if (error) {
2526 if (PSFA_OPEN == psfa->psfaa_type) {
2527 DTRACE_PROC1(spawn__open__failure, uintptr_t,
2528 psfa->psfaa_openargs.psfao_path);
2529 } else {
2530 DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
2531 }
2532 break;
2533 }
2534 }
2535
2536 if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
2537 return error;
2538 }
2539
2540 /*
2541 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
2542 * this spawn only) as if "close on exec" is the default
2543 * disposition of all pre-existing file descriptors. In this case,
2544 * the list of file descriptors mentioned in the file actions
2545 * are the only ones that can be inherited, so mark them now.
2546 *
2547 * The actual closing part comes later, in fdt_exec().
2548 */
2549 proc_fdlock(p);
2550 for (action = 0; action < px_sfap->psfa_act_count; action++) {
2551 _psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2552 int fd = psfa->psfaa_filedes;
2553
2554 switch (psfa->psfaa_type) {
2555 case PSFA_DUP2:
2556 case PSFA_FILEPORT_DUP2:
2557 fd = psfa->psfaa_dup2args.psfad_newfiledes;
2558 OS_FALLTHROUGH;
2559 case PSFA_OPEN:
2560 case PSFA_INHERIT:
2561 *fdflags(p, fd) |= UF_INHERIT;
2562 break;
2563
2564 case PSFA_CLOSE:
2565 case PSFA_CHDIR:
2566 case PSFA_FCHDIR:
2567 /*
2568 * Although PSFA_FCHDIR does have a file descriptor, it is not
2569 * *creating* one, thus we do not automatically mark it for
2570 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
2571 * wishes it to be inherited should use the PSFA_INHERIT action
2572 * explicitly.
2573 */
2574 break;
2575 }
2576 }
2577 proc_fdunlock(p);
2578
2579 return 0;
2580 }
2581
2582 #if CONFIG_MACF
2583 /*
2584 * Check that the extension's data is within the bounds of the
2585 * allocation storing all extensions' data
2586 */
2587 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)2588 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
2589 const _ps_mac_policy_extension_t *ext)
2590 {
2591 uint64_t dataend;
2592
2593 if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
2594 return EOVERFLOW;
2595 }
2596 if (__improbable(dataend > px_s->datalen)) {
2597 return EINVAL;
2598 }
2599
2600 return 0;
2601 }
2602
2603 /*
2604 * exec_spawnattr_getmacpolicyinfo
2605 */
2606 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)2607 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
2608 {
2609 const struct ip_px_smpx_s *px_s = macextensions;
2610 const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
2611 int i;
2612
2613 if (px_s == NULL) {
2614 return NULL;
2615 }
2616
2617 psmx = px_s->array;
2618 if (psmx == NULL) {
2619 return NULL;
2620 }
2621
2622 for (i = 0; i < psmx->psmx_count; i++) {
2623 const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
2624 if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
2625 if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
2626 panic("invalid mac policy extension data");
2627 }
2628 if (lenp != NULL) {
2629 *lenp = (size_t)extension->datalen;
2630 }
2631 return (void *)((uintptr_t)px_s->data + extension->dataoff);
2632 }
2633 }
2634
2635 if (lenp != NULL) {
2636 *lenp = 0;
2637 }
2638 return NULL;
2639 }
2640
2641 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)2642 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
2643 struct ip_px_smpx_s *pxsp)
2644 {
2645 _posix_spawn_mac_policy_extensions_t psmx = NULL;
2646 uint8_t *data = NULL;
2647 uint64_t datalen = 0;
2648 uint64_t dataoff = 0;
2649 int error = 0;
2650
2651 bzero(pxsp, sizeof(*pxsp));
2652
2653 if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
2654 px_args->mac_extensions_size > PAGE_SIZE) {
2655 error = EINVAL;
2656 goto bad;
2657 }
2658
2659 psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
2660 if (psmx == NULL) {
2661 error = ENOMEM;
2662 goto bad;
2663 }
2664
2665 error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
2666 if (error) {
2667 goto bad;
2668 }
2669
2670 size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
2671 if (extsize == 0 || extsize > px_args->mac_extensions_size) {
2672 error = EINVAL;
2673 goto bad;
2674 }
2675
2676 for (int i = 0; i < psmx->psmx_count; i++) {
2677 _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
2678 if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
2679 error = EINVAL;
2680 goto bad;
2681 }
2682 if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
2683 error = ENOMEM;
2684 goto bad;
2685 }
2686 }
2687
2688 data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
2689 if (data == NULL) {
2690 error = ENOMEM;
2691 goto bad;
2692 }
2693
2694 for (int i = 0; i < psmx->psmx_count; i++) {
2695 _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
2696
2697 #if !__LP64__
2698 if (extension->data > UINT32_MAX) {
2699 goto bad;
2700 }
2701 #endif
2702 error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
2703 if (error) {
2704 error = ENOMEM;
2705 goto bad;
2706 }
2707 extension->dataoff = dataoff;
2708 dataoff += extension->datalen;
2709 }
2710
2711 pxsp->array = psmx;
2712 pxsp->data = data;
2713 pxsp->datalen = datalen;
2714 return 0;
2715
2716 bad:
2717 kfree_data(psmx, px_args->mac_extensions_size);
2718 kfree_data(data, (vm_size_t)datalen);
2719 return error;
2720 }
2721 #endif /* CONFIG_MACF */
2722
2723 #if CONFIG_COALITIONS
2724 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])2725 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
2726 {
2727 for (int c = 0; c < COALITION_NUM_TYPES; c++) {
2728 if (coal[c]) {
2729 coalition_remove_active(coal[c]);
2730 coalition_release(coal[c]);
2731 }
2732 }
2733 }
2734 #endif
2735
2736 #if CONFIG_PERSONAS
2737 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)2738 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
2739 {
2740 int error = 0;
2741 struct persona *persona = NULL;
2742 int verify = px_persona->pspi_flags & POSIX_SPAWN_PERSONA_FLAGS_VERIFY;
2743
2744 if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
2745 return EPERM;
2746 }
2747
2748 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
2749 if (px_persona->pspi_ngroups > NGROUPS_MAX) {
2750 return EINVAL;
2751 }
2752 }
2753
2754 persona = persona_lookup(px_persona->pspi_id);
2755 if (!persona) {
2756 error = ESRCH;
2757 goto out;
2758 }
2759
2760 if (verify) {
2761 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
2762 if (px_persona->pspi_uid != persona_get_uid(persona)) {
2763 error = EINVAL;
2764 goto out;
2765 }
2766 }
2767 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
2768 if (px_persona->pspi_gid != persona_get_gid(persona)) {
2769 error = EINVAL;
2770 goto out;
2771 }
2772 }
2773 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
2774 size_t ngroups = 0;
2775 gid_t groups[NGROUPS_MAX];
2776
2777 if (persona_get_groups(persona, &ngroups, groups,
2778 px_persona->pspi_ngroups) != 0) {
2779 error = EINVAL;
2780 goto out;
2781 }
2782 if (ngroups != px_persona->pspi_ngroups) {
2783 error = EINVAL;
2784 goto out;
2785 }
2786 while (ngroups--) {
2787 if (px_persona->pspi_groups[ngroups] != groups[ngroups]) {
2788 error = EINVAL;
2789 goto out;
2790 }
2791 }
2792 if (px_persona->pspi_gmuid != persona_get_gmuid(persona)) {
2793 error = EINVAL;
2794 goto out;
2795 }
2796 }
2797 }
2798
2799 out:
2800 if (persona) {
2801 persona_put(persona);
2802 }
2803
2804 return error;
2805 }
2806
2807 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)2808 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
2809 {
2810 int ret;
2811 kauth_cred_t cred;
2812 struct persona *persona = NULL;
2813 int override = !!(px_persona->pspi_flags & POSIX_SPAWN_PERSONA_FLAGS_OVERRIDE);
2814
2815 if (!override) {
2816 return persona_proc_adopt_id(p, px_persona->pspi_id, NULL);
2817 }
2818
2819 /*
2820 * we want to spawn into the given persona, but we want to override
2821 * the kauth with a different UID/GID combo
2822 */
2823 persona = persona_lookup(px_persona->pspi_id);
2824 if (!persona) {
2825 return ESRCH;
2826 }
2827
2828 cred = persona_get_cred(persona);
2829 if (!cred) {
2830 ret = EINVAL;
2831 goto out;
2832 }
2833
2834 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
2835 cred = kauth_cred_setresuid(cred,
2836 px_persona->pspi_uid,
2837 px_persona->pspi_uid,
2838 px_persona->pspi_uid,
2839 KAUTH_UID_NONE);
2840 }
2841
2842 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
2843 cred = kauth_cred_setresgid(cred,
2844 px_persona->pspi_gid,
2845 px_persona->pspi_gid,
2846 px_persona->pspi_gid);
2847 }
2848
2849 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
2850 cred = kauth_cred_setgroups(cred,
2851 px_persona->pspi_groups,
2852 px_persona->pspi_ngroups,
2853 px_persona->pspi_gmuid);
2854 }
2855
2856 ret = persona_proc_adopt(p, persona, cred);
2857
2858 out:
2859 persona_put(persona);
2860 return ret;
2861 }
2862 #endif
2863
2864 #if __arm64__
2865 #if DEVELOPMENT || DEBUG
2866 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
2867 LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
2868
2869 __startup_func
2870 static void
legacy_footprint_entitlement_mode_init(void)2871 legacy_footprint_entitlement_mode_init(void)
2872 {
2873 /*
2874 * legacy_footprint_entitlement_mode specifies the behavior we want associated
2875 * with the entitlement. The supported modes are:
2876 *
2877 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
2878 * Indicates that we want every process to have the memory accounting
2879 * that is available in iOS 12.0 and beyond.
2880 *
2881 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
2882 * Indicates that for every process that has the 'legacy footprint entitlement',
2883 * we want to give it the old iOS 11.0 accounting behavior which accounted some
2884 * of the process's memory to the kernel.
2885 *
2886 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
2887 * Indicates that for every process that has the 'legacy footprint entitlement',
2888 * we want it to have a higher memory limit which will help them acclimate to the
2889 * iOS 12.0 (& beyond) accounting behavior that does the right accounting.
2890 * The bonus added to the system-wide task limit to calculate this higher memory limit
2891 * is available in legacy_footprint_bonus_mb.
2892 */
2893
2894 if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
2895 legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
2896 legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
2897 }
2898 }
2899 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
2900 #else
2901 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
2902 #endif
2903
2904 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)2905 proc_legacy_footprint_entitled(proc_t p, task_t task)
2906 {
2907 #pragma unused(p)
2908 boolean_t legacy_footprint_entitled;
2909
2910 switch (legacy_footprint_entitlement_mode) {
2911 case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
2912 /* the entitlement is ignored */
2913 break;
2914 case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
2915 /* the entitlement grants iOS11 legacy accounting */
2916 legacy_footprint_entitled = IOTaskHasEntitlement(task,
2917 "com.apple.private.memory.legacy_footprint");
2918 if (legacy_footprint_entitled) {
2919 task_set_legacy_footprint(task);
2920 }
2921 break;
2922 case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
2923 /* the entitlement grants a footprint limit increase */
2924 legacy_footprint_entitled = IOTaskHasEntitlement(task,
2925 "com.apple.private.memory.legacy_footprint");
2926 if (legacy_footprint_entitled) {
2927 task_set_extra_footprint_limit(task);
2928 }
2929 break;
2930 default:
2931 break;
2932 }
2933 }
2934
2935 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)2936 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
2937 {
2938 #pragma unused(p)
2939 boolean_t ios13extended_footprint_entitled;
2940
2941 /* the entitlement grants a footprint limit increase */
2942 ios13extended_footprint_entitled = IOTaskHasEntitlement(task,
2943 "com.apple.developer.memory.ios13extended_footprint");
2944 if (ios13extended_footprint_entitled) {
2945 task_set_ios13extended_footprint_limit(task);
2946 }
2947 }
2948
2949 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)2950 proc_increased_memory_limit_entitled(proc_t p, task_t task)
2951 {
2952 bool entitled = memorystatus_task_has_increased_memory_limit_entitlement(task);
2953
2954 if (entitled) {
2955 memorystatus_act_on_entitled_task_limit(p);
2956 }
2957 }
2958
2959 /*
2960 * Check for any of the various entitlements that permit a higher
2961 * task footprint limit or alternate accounting and apply them.
2962 */
2963 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)2964 proc_footprint_entitlement_hacks(proc_t p, task_t task)
2965 {
2966 proc_legacy_footprint_entitled(p, task);
2967 proc_ios13extended_footprint_entitled(p, task);
2968 proc_increased_memory_limit_entitled(p, task);
2969 }
2970 #endif /* __arm64__ */
2971
2972 #if CONFIG_MACF
2973 /*
2974 * Processes with certain entitlements are granted a jumbo-size VM map.
2975 */
2976 static inline void
proc_apply_jit_and_jumbo_va_policies(proc_t p,task_t task)2977 proc_apply_jit_and_jumbo_va_policies(proc_t p, task_t task)
2978 {
2979 bool jit_entitled;
2980 jit_entitled = (mac_proc_check_map_anon(p, 0, 0, 0, MAP_JIT, NULL) == 0);
2981 if (jit_entitled || (IOTaskHasEntitlement(task,
2982 "com.apple.developer.kernel.extended-virtual-addressing")) ||
2983 memorystatus_task_has_increased_memory_limit_entitlement(task)) {
2984 vm_map_set_jumbo(get_task_map(task));
2985 if (jit_entitled) {
2986 vm_map_set_jit_entitled(get_task_map(task));
2987
2988 }
2989 }
2990 }
2991 #endif /* CONFIG_MACF */
2992
2993 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)2994 spawn_posix_cred_adopt(proc_t p,
2995 struct _posix_spawn_posix_cred_info *px_pcred_info)
2996 {
2997 int error = 0;
2998
2999 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3000 struct setgid_args args = {
3001 .gid = px_pcred_info->pspci_gid,
3002 };
3003 error = setgid(p, &args, NULL);
3004 if (error) {
3005 return error;
3006 }
3007 }
3008
3009 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3010 error = setgroups_internal(p,
3011 px_pcred_info->pspci_ngroups,
3012 px_pcred_info->pspci_groups,
3013 px_pcred_info->pspci_gmuid);
3014 if (error) {
3015 return error;
3016 }
3017 }
3018
3019 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3020 struct setuid_args args = {
3021 .uid = px_pcred_info->pspci_uid,
3022 };
3023 error = setuid(p, &args, NULL);
3024 if (error) {
3025 return error;
3026 }
3027 }
3028 return 0;
3029 }
3030
3031 /*
3032 * posix_spawn
3033 *
3034 * Parameters: uap->pid Pointer to pid return area
3035 * uap->fname File name to exec
3036 * uap->argp Argument list
3037 * uap->envp Environment list
3038 *
3039 * Returns: 0 Success
3040 * EINVAL Invalid argument
3041 * ENOTSUP Not supported
3042 * ENOEXEC Executable file format error
3043 * exec_activate_image:EINVAL Invalid argument
3044 * exec_activate_image:EACCES Permission denied
3045 * exec_activate_image:EINTR Interrupted function
3046 * exec_activate_image:ENOMEM Not enough space
3047 * exec_activate_image:EFAULT Bad address
3048 * exec_activate_image:ENAMETOOLONG Filename too long
3049 * exec_activate_image:ENOEXEC Executable file format error
3050 * exec_activate_image:ETXTBSY Text file busy [misuse of error code]
3051 * exec_activate_image:EAUTH Image decryption failed
3052 * exec_activate_image:EBADEXEC The executable is corrupt/unknown
3053 * exec_activate_image:???
3054 * mac_execve_enter:???
3055 *
3056 * TODO: Expect to need __mac_posix_spawn() at some point...
3057 * Handle posix_spawnattr_t
3058 * Handle posix_spawn_file_actions_t
3059 */
3060 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3061 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3062 {
3063 proc_t p = ap;
3064 user_addr_t pid = uap->pid;
3065 int ival[2]; /* dummy retval for setpgid() */
3066 char *subsystem_root_path = NULL;
3067 struct image_params *imgp = NULL;
3068 struct vnode_attr *vap = NULL;
3069 struct vnode_attr *origvap = NULL;
3070 struct uthread *uthread = 0; /* compiler complains if not set to 0*/
3071 int error, sig;
3072 int is_64 = IS_64BIT_PROCESS(p);
3073 struct vfs_context context;
3074 struct user__posix_spawn_args_desc px_args = {};
3075 struct _posix_spawnattr px_sa = {};
3076 _posix_spawn_file_actions_t px_sfap = NULL;
3077 _posix_spawn_port_actions_t px_spap = NULL;
3078 struct __kern_sigaction vec;
3079 boolean_t spawn_no_exec = FALSE;
3080 boolean_t proc_transit_set = TRUE;
3081 boolean_t exec_done = FALSE;
3082 struct exec_port_actions port_actions = { };
3083 vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3084 task_t old_task = current_task();
3085 task_t new_task = NULL;
3086 boolean_t should_release_proc_ref = FALSE;
3087 void *inherit = NULL;
3088 #if CONFIG_PERSONAS
3089 struct _posix_spawn_persona_info *px_persona = NULL;
3090 #endif
3091 struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3092 struct {
3093 struct image_params imgp;
3094 struct vnode_attr va;
3095 struct vnode_attr origva;
3096 } *__spawn_data;
3097
3098 /*
3099 * Allocate a big chunk for locals instead of using stack since these
3100 * structures are pretty big.
3101 */
3102 __spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3103 if (__spawn_data == NULL) {
3104 error = ENOMEM;
3105 goto bad;
3106 }
3107 imgp = &__spawn_data->imgp;
3108 vap = &__spawn_data->va;
3109 origvap = &__spawn_data->origva;
3110
3111 /* Initialize the common data in the image_params structure */
3112 imgp->ip_user_fname = uap->path;
3113 imgp->ip_user_argv = uap->argv;
3114 imgp->ip_user_envv = uap->envp;
3115 imgp->ip_vattr = vap;
3116 imgp->ip_origvattr = origvap;
3117 imgp->ip_vfs_context = &context;
3118 imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3119 imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3120 imgp->ip_mac_return = 0;
3121 imgp->ip_px_persona = NULL;
3122 imgp->ip_px_pcred_info = NULL;
3123 imgp->ip_cs_error = OS_REASON_NULL;
3124 imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3125 imgp->ip_subsystem_root_path = NULL;
3126 imgp->ip_inherited_shared_region_id = NULL;
3127 imgp->ip_inherited_jop_pid = 0;
3128
3129 if (uap->adesc != USER_ADDR_NULL) {
3130 if (is_64) {
3131 error = copyin(uap->adesc, &px_args, sizeof(px_args));
3132 } else {
3133 struct user32__posix_spawn_args_desc px_args32;
3134
3135 error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3136
3137 /*
3138 * Convert arguments descriptor from external 32 bit
3139 * representation to internal 64 bit representation
3140 */
3141 px_args.attr_size = px_args32.attr_size;
3142 px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3143 px_args.file_actions_size = px_args32.file_actions_size;
3144 px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3145 px_args.port_actions_size = px_args32.port_actions_size;
3146 px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3147 px_args.mac_extensions_size = px_args32.mac_extensions_size;
3148 px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3149 px_args.coal_info_size = px_args32.coal_info_size;
3150 px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3151 px_args.persona_info_size = px_args32.persona_info_size;
3152 px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3153 px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3154 px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3155 px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3156 px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3157 }
3158 if (error) {
3159 goto bad;
3160 }
3161
3162 if (px_args.attr_size != 0) {
3163 /*
3164 * We are not copying the port_actions pointer,
3165 * because we already have it from px_args.
3166 * This is a bit fragile: <rdar://problem/16427422>
3167 */
3168
3169 if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3170 goto bad;
3171 }
3172
3173 imgp->ip_px_sa = &px_sa;
3174 }
3175 if (px_args.file_actions_size != 0) {
3176 /* Limit file_actions to allowed number of open files */
3177 size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3178
3179 if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3180 maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3181 error = EINVAL;
3182 goto bad;
3183 }
3184
3185 px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3186 if (px_sfap == NULL) {
3187 error = ENOMEM;
3188 goto bad;
3189 }
3190 imgp->ip_px_sfa = px_sfap;
3191
3192 if ((error = copyin(px_args.file_actions, px_sfap,
3193 px_args.file_actions_size)) != 0) {
3194 goto bad;
3195 }
3196
3197 /* Verify that the action count matches the struct size */
3198 size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3199 if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3200 error = EINVAL;
3201 goto bad;
3202 }
3203 }
3204 if (px_args.port_actions_size != 0) {
3205 /* Limit port_actions to one page of data */
3206 if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3207 px_args.port_actions_size > PAGE_SIZE) {
3208 error = EINVAL;
3209 goto bad;
3210 }
3211
3212 px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3213 if (px_spap == NULL) {
3214 error = ENOMEM;
3215 goto bad;
3216 }
3217 imgp->ip_px_spa = px_spap;
3218
3219 if ((error = copyin(px_args.port_actions, px_spap,
3220 px_args.port_actions_size)) != 0) {
3221 goto bad;
3222 }
3223
3224 /* Verify that the action count matches the struct size */
3225 size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3226 if (pasize == 0 || pasize != px_args.port_actions_size) {
3227 error = EINVAL;
3228 goto bad;
3229 }
3230 }
3231 #if CONFIG_PERSONAS
3232 /* copy in the persona info */
3233 if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3234 /* for now, we need the exact same struct in user space */
3235 if (px_args.persona_info_size != sizeof(*px_persona)) {
3236 error = ERANGE;
3237 goto bad;
3238 }
3239
3240 px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3241 if (px_persona == NULL) {
3242 error = ENOMEM;
3243 goto bad;
3244 }
3245 imgp->ip_px_persona = px_persona;
3246
3247 if ((error = copyin(px_args.persona_info, px_persona,
3248 px_args.persona_info_size)) != 0) {
3249 goto bad;
3250 }
3251 if ((error = spawn_validate_persona(px_persona)) != 0) {
3252 goto bad;
3253 }
3254 }
3255 #endif
3256 /* copy in the posix cred info */
3257 if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
3258 /* for now, we need the exact same struct in user space */
3259 if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
3260 error = ERANGE;
3261 goto bad;
3262 }
3263
3264 if (!kauth_cred_issuser(kauth_cred_get())) {
3265 error = EPERM;
3266 goto bad;
3267 }
3268
3269 px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
3270 if (px_pcred_info == NULL) {
3271 error = ENOMEM;
3272 goto bad;
3273 }
3274 imgp->ip_px_pcred_info = px_pcred_info;
3275
3276 if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
3277 px_args.posix_cred_info_size)) != 0) {
3278 goto bad;
3279 }
3280
3281 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3282 if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
3283 error = EINVAL;
3284 goto bad;
3285 }
3286 }
3287 }
3288 #if CONFIG_MACF
3289 if (px_args.mac_extensions_size != 0) {
3290 if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
3291 goto bad;
3292 }
3293 }
3294 #endif /* CONFIG_MACF */
3295 if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
3296 /*
3297 * If a valid-looking subsystem root has been
3298 * specified...
3299 */
3300 if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
3301 /*
3302 * ...AND the parent has the entitlement, copy
3303 * the subsystem root path in.
3304 */
3305 subsystem_root_path = zalloc_flags(ZV_NAMEI,
3306 Z_WAITOK | Z_ZERO | Z_NOFAIL);
3307
3308 if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
3309 goto bad;
3310 }
3311
3312 /* Paranoia */
3313 subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
3314 }
3315 }
3316 }
3317
3318 /* set uthread to parent */
3319 uthread = current_uthread();
3320
3321 /*
3322 * <rdar://6640530>; this does not result in a behaviour change
3323 * relative to Leopard, so there should not be any existing code
3324 * which depends on it.
3325 */
3326
3327 if (imgp->ip_px_sa != NULL) {
3328 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
3329 if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
3330 imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
3331 }
3332 #if (DEVELOPMENT || DEBUG)
3333 if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
3334 imgp->ip_flags |= IMGPF_ALT_ROSETTA;
3335 }
3336 #endif
3337
3338 if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
3339 goto bad;
3340 }
3341 }
3342
3343 /*
3344 * If we don't have the extension flag that turns "posix_spawn()"
3345 * into "execve() with options", then we will be creating a new
3346 * process which does not inherit memory from the parent process,
3347 * which is one of the most expensive things about using fork()
3348 * and execve().
3349 */
3350 if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3351 /* Set the new task's coalition, if it is requested. */
3352 coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
3353 #if CONFIG_COALITIONS
3354 int i, ncoals;
3355 kern_return_t kr = KERN_SUCCESS;
3356 struct _posix_spawn_coalition_info coal_info;
3357 int coal_role[COALITION_NUM_TYPES];
3358
3359 if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
3360 goto do_fork1;
3361 }
3362
3363 memset(&coal_info, 0, sizeof(coal_info));
3364
3365 if (px_args.coal_info_size > sizeof(coal_info)) {
3366 px_args.coal_info_size = sizeof(coal_info);
3367 }
3368 error = copyin(px_args.coal_info,
3369 &coal_info, px_args.coal_info_size);
3370 if (error != 0) {
3371 goto bad;
3372 }
3373
3374 ncoals = 0;
3375 for (i = 0; i < COALITION_NUM_TYPES; i++) {
3376 uint64_t cid = coal_info.psci_info[i].psci_id;
3377 if (cid != 0) {
3378 /*
3379 * don't allow tasks which are not in a
3380 * privileged coalition to spawn processes
3381 * into coalitions other than their own
3382 */
3383 if (!task_is_in_privileged_coalition(p->task, i) &&
3384 !IOTaskHasEntitlement(p->task, COALITION_SPAWN_ENTITLEMENT)) {
3385 coal_dbg("ERROR: %d not in privilegd "
3386 "coalition of type %d",
3387 proc_getpid(p), i);
3388 spawn_coalitions_release_all(coal);
3389 error = EPERM;
3390 goto bad;
3391 }
3392
3393 coal_dbg("searching for coalition id:%llu", cid);
3394 /*
3395 * take a reference and activation on the
3396 * coalition to guard against free-while-spawn
3397 * races
3398 */
3399 coal[i] = coalition_find_and_activate_by_id(cid);
3400 if (coal[i] == COALITION_NULL) {
3401 coal_dbg("could not find coalition id:%llu "
3402 "(perhaps it has been terminated or reaped)", cid);
3403 /*
3404 * release any other coalition's we
3405 * may have a reference to
3406 */
3407 spawn_coalitions_release_all(coal);
3408 error = ESRCH;
3409 goto bad;
3410 }
3411 if (coalition_type(coal[i]) != i) {
3412 coal_dbg("coalition with id:%lld is not of type:%d"
3413 " (it's type:%d)", cid, i, coalition_type(coal[i]));
3414 error = ESRCH;
3415 goto bad;
3416 }
3417 coal_role[i] = coal_info.psci_info[i].psci_role;
3418 ncoals++;
3419 }
3420 }
3421 if (ncoals < COALITION_NUM_TYPES) {
3422 /*
3423 * If the user is attempting to spawn into a subset of
3424 * the known coalition types, then make sure they have
3425 * _at_least_ specified a resource coalition. If not,
3426 * the following fork1() call will implicitly force an
3427 * inheritance from 'p' and won't actually spawn the
3428 * new task into the coalitions the user specified.
3429 * (also the call to coalitions_set_roles will panic)
3430 */
3431 if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
3432 spawn_coalitions_release_all(coal);
3433 error = EINVAL;
3434 goto bad;
3435 }
3436 }
3437 do_fork1:
3438 #endif /* CONFIG_COALITIONS */
3439
3440 /*
3441 * note that this will implicitly inherit the
3442 * caller's persona (if it exists)
3443 */
3444 error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
3445 /* returns a thread and task reference */
3446
3447 if (error == 0) {
3448 new_task = get_threadtask(imgp->ip_new_thread);
3449 }
3450 #if CONFIG_COALITIONS
3451 /* set the roles of this task within each given coalition */
3452 if (error == 0) {
3453 kr = coalitions_set_roles(coal, new_task, coal_role);
3454 if (kr != KERN_SUCCESS) {
3455 error = EINVAL;
3456 }
3457 if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
3458 MACH_COALITION_ADOPT))) {
3459 for (i = 0; i < COALITION_NUM_TYPES; i++) {
3460 if (coal[i] != COALITION_NULL) {
3461 /*
3462 * On 32-bit targets, uniqueid
3463 * will get truncated to 32 bits
3464 */
3465 KDBG_RELEASE(MACHDBG_CODE(
3466 DBG_MACH_COALITION,
3467 MACH_COALITION_ADOPT),
3468 coalition_id(coal[i]),
3469 get_task_uniqueid(new_task));
3470 }
3471 }
3472 }
3473 }
3474
3475 /* drop our references and activations - fork1() now holds them */
3476 spawn_coalitions_release_all(coal);
3477 #endif /* CONFIG_COALITIONS */
3478 if (error != 0) {
3479 goto bad;
3480 }
3481 imgp->ip_flags |= IMGPF_SPAWN; /* spawn w/o exec */
3482 spawn_no_exec = TRUE; /* used in later tests */
3483 } else {
3484 /*
3485 * For execve case, create a new task and thread
3486 * which points to current_proc. The current_proc will point
3487 * to the new task after image activation and proc ref drain.
3488 *
3489 * proc (current_proc) <----- old_task (current_task)
3490 * ^ | ^
3491 * | | |
3492 * | ----------------------------------
3493 * |
3494 * --------- new_task (task marked as TF_EXEC_COPY)
3495 *
3496 * After image activation, the proc will point to the new task
3497 * and would look like following.
3498 *
3499 * proc (current_proc) <----- old_task (current_task, marked as TPF_DID_EXEC)
3500 * ^ |
3501 * | |
3502 * | ----------> new_task
3503 * | |
3504 * -----------------
3505 *
3506 * During exec any transition from new_task -> proc is fine, but don't allow
3507 * transition from proc->task, since it will modify old_task.
3508 */
3509 imgp->ip_new_thread = fork_create_child(old_task,
3510 NULL,
3511 p,
3512 FALSE,
3513 p->p_flag & P_LP64,
3514 task_get_64bit_data(old_task),
3515 TRUE);
3516 /* task and thread ref returned by fork_create_child */
3517 if (imgp->ip_new_thread == NULL) {
3518 error = ENOMEM;
3519 goto bad;
3520 }
3521
3522 new_task = get_threadtask(imgp->ip_new_thread);
3523 imgp->ip_flags |= IMGPF_EXEC;
3524 }
3525
3526 if (spawn_no_exec) {
3527 p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
3528
3529 /*
3530 * We had to wait until this point before firing the
3531 * proc:::create probe, otherwise p would not point to the
3532 * child process.
3533 */
3534 DTRACE_PROC1(create, proc_t, p);
3535 }
3536 assert(p != NULL);
3537
3538 if (subsystem_root_path) {
3539 /* If a subsystem root was specified, swap it in */
3540 char * old_subsystem_root_path = p->p_subsystem_root_path;
3541 p->p_subsystem_root_path = subsystem_root_path;
3542 subsystem_root_path = old_subsystem_root_path;
3543 }
3544
3545 /* We'll need the subsystem root for setting up Apple strings */
3546 imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
3547
3548 context.vc_thread = imgp->ip_new_thread;
3549 context.vc_ucred = proc_ucred(p); /* XXX must NOT be kauth_cred_get() */
3550
3551 /*
3552 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
3553 * to handle the file_actions.
3554 */
3555
3556 /* Has spawn file actions? */
3557 if (imgp->ip_px_sfa != NULL) {
3558 /*
3559 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
3560 * is handled in exec_handle_file_actions().
3561 */
3562 #if CONFIG_AUDIT
3563 /*
3564 * The file actions auditing can overwrite the upath of
3565 * AUE_POSIX_SPAWN audit record. Save the audit record.
3566 */
3567 struct kaudit_record *save_uu_ar = uthread->uu_ar;
3568 uthread->uu_ar = NULL;
3569 #endif
3570 error = exec_handle_file_actions(imgp,
3571 imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
3572 #if CONFIG_AUDIT
3573 /* Restore the AUE_POSIX_SPAWN audit record. */
3574 uthread->uu_ar = save_uu_ar;
3575 #endif
3576 if (error != 0) {
3577 goto bad;
3578 }
3579 }
3580
3581 /* Has spawn port actions? */
3582 if (imgp->ip_px_spa != NULL) {
3583 #if CONFIG_AUDIT
3584 /*
3585 * Do the same for the port actions as we did for the file
3586 * actions. Save the AUE_POSIX_SPAWN audit record.
3587 */
3588 struct kaudit_record *save_uu_ar = uthread->uu_ar;
3589 uthread->uu_ar = NULL;
3590 #endif
3591 error = exec_handle_port_actions(imgp, &port_actions);
3592 #if CONFIG_AUDIT
3593 /* Restore the AUE_POSIX_SPAWN audit record. */
3594 uthread->uu_ar = save_uu_ar;
3595 #endif
3596 if (error != 0) {
3597 goto bad;
3598 }
3599 }
3600
3601 /* Has spawn attr? */
3602 if (imgp->ip_px_sa != NULL) {
3603 /*
3604 * Reset UID/GID to parent's RUID/RGID; This works only
3605 * because the operation occurs before the call
3606 * to exec_handle_sugid() by the image activator called
3607 * from exec_activate_image().
3608 *
3609 * POSIX requires that any setuid/setgid bits on the process
3610 * image will take precedence over the spawn attributes
3611 * (re)setting them.
3612 *
3613 * Modifications to p_ucred must be guarded using the
3614 * proc's ucred lock. This prevents others from accessing
3615 * a garbage credential.
3616 */
3617 if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
3618 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred){
3619 return kauth_cred_setuidgid(my_cred,
3620 kauth_cred_getruid(my_cred),
3621 kauth_cred_getrgid(my_cred));
3622 });
3623 }
3624
3625 if (imgp->ip_px_pcred_info) {
3626 if (!spawn_no_exec) {
3627 error = ENOTSUP;
3628 goto bad;
3629 }
3630
3631 error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
3632 if (error != 0) {
3633 goto bad;
3634 }
3635 }
3636
3637 #if CONFIG_PERSONAS
3638 if (imgp->ip_px_persona != NULL) {
3639 if (!spawn_no_exec) {
3640 error = ENOTSUP;
3641 goto bad;
3642 }
3643
3644 /*
3645 * If we were asked to spawn a process into a new persona,
3646 * do the credential switch now (which may override the UID/GID
3647 * inherit done just above). It's important to do this switch
3648 * before image activation both for reasons stated above, and
3649 * to ensure that the new persona has access to the image/file
3650 * being executed.
3651 */
3652 error = spawn_persona_adopt(p, imgp->ip_px_persona);
3653 if (error != 0) {
3654 goto bad;
3655 }
3656 }
3657 #endif /* CONFIG_PERSONAS */
3658 #if !SECURE_KERNEL
3659 /*
3660 * Disable ASLR for the spawned process.
3661 *
3662 * But only do so if we are not embedded + RELEASE.
3663 * While embedded allows for a boot-arg (-disable_aslr)
3664 * to deal with this (which itself is only honored on
3665 * DEVELOPMENT or DEBUG builds of xnu), it is often
3666 * useful or necessary to disable ASLR on a per-process
3667 * basis for unit testing and debugging.
3668 */
3669 if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
3670 OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
3671 }
3672 #endif /* !SECURE_KERNEL */
3673
3674 /* Randomize high bits of ASLR slide */
3675 if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
3676 imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
3677 }
3678
3679 #if !SECURE_KERNEL
3680 /*
3681 * Forcibly disallow execution from data pages for the spawned process
3682 * even if it would otherwise be permitted by the architecture default.
3683 */
3684 if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
3685 imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
3686 }
3687 #endif /* !SECURE_KERNEL */
3688
3689 #if __has_feature(ptrauth_calls)
3690 if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
3691 imgp->ip_flags |= IMGPF_RESLIDE;
3692 }
3693 #endif /* __has_feature(ptrauth_calls) */
3694
3695 if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
3696 POSIX_SPAWN_PROC_TYPE_DRIVER) {
3697 imgp->ip_flags |= IMGPF_DRIVER;
3698 }
3699 }
3700
3701 /*
3702 * Disable ASLR during image activation. This occurs either if the
3703 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
3704 * P_DISABLE_ASLR was inherited from the parent process.
3705 */
3706 if (p->p_flag & P_DISABLE_ASLR) {
3707 imgp->ip_flags |= IMGPF_DISABLE_ASLR;
3708 }
3709
3710 /*
3711 * Clear transition flag so we won't hang if exec_activate_image() causes
3712 * an automount (and launchd does a proc sysctl to service it).
3713 *
3714 * <rdar://problem/6848672>, <rdar://problem/5959568>.
3715 */
3716 if (spawn_no_exec) {
3717 proc_transend(p, 0);
3718 proc_transit_set = 0;
3719 }
3720
3721 #if MAC_SPAWN /* XXX */
3722 if (uap->mac_p != USER_ADDR_NULL) {
3723 error = mac_execve_enter(uap->mac_p, imgp);
3724 if (error) {
3725 goto bad;
3726 }
3727 }
3728 #endif
3729
3730 /*
3731 * Activate the image
3732 */
3733 error = exec_activate_image(imgp);
3734 #if defined(HAS_APPLE_PAC)
3735 ml_task_set_jop_pid_from_shared_region(new_task);
3736 ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
3737 ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
3738 ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
3739 #endif
3740
3741 if (error == 0 && !spawn_no_exec) {
3742 p = proc_exec_switch_task(p, old_task, new_task, imgp->ip_new_thread, &inherit);
3743 /* proc ref returned */
3744 should_release_proc_ref = TRUE;
3745 }
3746
3747 if (error == 0) {
3748 /* process completed the exec */
3749 exec_done = TRUE;
3750 }
3751
3752 if (!error && imgp->ip_px_sa != NULL) {
3753 thread_t child_thread = imgp->ip_new_thread;
3754 uthread_t child_uthread = get_bsdthread_info(child_thread);
3755
3756 /*
3757 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
3758 * activation, else when image activation fails (before the point of no
3759 * return) would leave the parent process in a modified state.
3760 */
3761 if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
3762 struct setpgid_args spga;
3763 spga.pid = proc_getpid(p);
3764 spga.pgid = px_sa.psa_pgroup;
3765 /*
3766 * Effectively, call setpgid() system call; works
3767 * because there are no pointer arguments.
3768 */
3769 if ((error = setpgid(p, &spga, ival)) != 0) {
3770 goto bad;
3771 }
3772 }
3773
3774 if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
3775 error = setsid_internal(p);
3776 if (error != 0) {
3777 goto bad;
3778 }
3779 }
3780
3781 /*
3782 * If we have a spawn attr, and it contains signal related flags,
3783 * the we need to process them in the "context" of the new child
3784 * process, so we have to process it following image activation,
3785 * prior to making the thread runnable in user space. This is
3786 * necessitated by some signal information being per-thread rather
3787 * than per-process, and we don't have the new allocation in hand
3788 * until after the image is activated.
3789 */
3790
3791 /*
3792 * Mask a list of signals, instead of them being unmasked, if
3793 * they were unmasked in the parent; note that some signals
3794 * are not maskable.
3795 */
3796 if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
3797 child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
3798 }
3799 /*
3800 * Default a list of signals instead of ignoring them, if
3801 * they were ignored in the parent. Note that we pass
3802 * spawn_no_exec to setsigvec() to indicate that we called
3803 * fork1() and therefore do not need to call proc_signalstart()
3804 * internally.
3805 */
3806 if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
3807 vec.sa_handler = SIG_DFL;
3808 vec.sa_tramp = 0;
3809 vec.sa_mask = 0;
3810 vec.sa_flags = 0;
3811 for (sig = 1; sig < NSIG; sig++) {
3812 if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
3813 error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
3814 }
3815 }
3816 }
3817
3818 /*
3819 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
3820 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
3821 * limit.
3822 *
3823 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
3824 */
3825 if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
3826 /*
3827 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
3828 * an entitlement to configure the monitor a certain way seems silly, since
3829 * whomever is turning it on could just as easily choose not to do so.
3830 */
3831 error = proc_set_task_ruse_cpu(p->task,
3832 TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
3833 (uint8_t)px_sa.psa_cpumonitor_percent,
3834 px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
3835 0, TRUE);
3836 }
3837
3838
3839 if (px_pcred_info &&
3840 (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
3841 /*
3842 * setlogin() must happen after setsid()
3843 */
3844 setlogin_internal(p, px_pcred_info->pspci_login);
3845 }
3846 }
3847
3848 bad:
3849
3850 if (error == 0) {
3851 /* reset delay idle sleep status if set */
3852 #if CONFIG_DELAY_IDLE_SLEEP
3853 if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
3854 OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
3855 }
3856 #endif /* CONFIG_DELAY_IDLE_SLEEP */
3857 /* upon successful spawn, re/set the proc control state */
3858 if (imgp->ip_px_sa != NULL) {
3859 switch (px_sa.psa_pcontrol) {
3860 case POSIX_SPAWN_PCONTROL_THROTTLE:
3861 p->p_pcaction = P_PCTHROTTLE;
3862 break;
3863 case POSIX_SPAWN_PCONTROL_SUSPEND:
3864 p->p_pcaction = P_PCSUSP;
3865 break;
3866 case POSIX_SPAWN_PCONTROL_KILL:
3867 p->p_pcaction = P_PCKILL;
3868 break;
3869 case POSIX_SPAWN_PCONTROL_NONE:
3870 default:
3871 p->p_pcaction = 0;
3872 break;
3873 }
3874 ;
3875 }
3876 exec_resettextvp(p, imgp);
3877
3878 #if CONFIG_MEMORYSTATUS
3879 /* Set jetsam priority for DriverKit processes */
3880 if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
3881 px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
3882 }
3883
3884 /* Has jetsam attributes? */
3885 if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
3886 /*
3887 * With 2-level high-water-mark support, POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no
3888 * longer relevant, as background limits are described via the inactive limit slots.
3889 *
3890 * That said, however, if the POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in,
3891 * we attempt to mimic previous behavior by forcing the BG limit data into the
3892 * inactive/non-fatal mode and force the active slots to hold system_wide/fatal mode.
3893 */
3894
3895 if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
3896 memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
3897 (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
3898 TRUE,
3899 -1, TRUE,
3900 px_sa.psa_memlimit_inactive, FALSE);
3901 } else {
3902 memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
3903 (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
3904 TRUE,
3905 px_sa.psa_memlimit_active,
3906 (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL),
3907 px_sa.psa_memlimit_inactive,
3908 (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL));
3909 }
3910 }
3911
3912 /* Has jetsam relaunch behavior? */
3913 if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
3914 /*
3915 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
3916 * This data would be used by the jetsam subsystem to determine the position and protection
3917 * offered to this process on dirty -> clean transitions.
3918 */
3919 int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
3920 switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
3921 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
3922 relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
3923 break;
3924 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
3925 relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
3926 break;
3927 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
3928 relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
3929 break;
3930 default:
3931 break;
3932 }
3933 memorystatus_relaunch_flags_update(p, relaunch_flags);
3934 }
3935
3936 #endif /* CONFIG_MEMORYSTATUS */
3937 if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
3938 task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
3939 }
3940
3941 #if CONFIG_PROC_RESOURCE_LIMITS
3942 if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
3943 task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
3944 (uint32_t)px_sa.psa_port_hard_limit);
3945 }
3946
3947 if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
3948 proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
3949 (int)px_sa.psa_filedesc_hard_limit);
3950 }
3951 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
3952
3953 /* Disable wakeup monitoring for DriverKit processes */
3954 if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
3955 uint32_t flags = WAKEMON_DISABLE;
3956 task_wakeups_monitor_ctl(new_task, &flags, NULL);
3957 }
3958 }
3959
3960 /*
3961 * If we successfully called fork1(), we always need to do this;
3962 * we identify this case by noting the IMGPF_SPAWN flag. This is
3963 * because we come back from that call with signals blocked in the
3964 * child, and we have to unblock them, but we want to wait until
3965 * after we've performed any spawn actions. This has to happen
3966 * before check_for_signature(), which uses psignal.
3967 */
3968 if (spawn_no_exec) {
3969 if (proc_transit_set) {
3970 proc_transend(p, 0);
3971 }
3972
3973 /*
3974 * Drop the signal lock on the child which was taken on our
3975 * behalf by forkproc()/cloneproc() to prevent signals being
3976 * received by the child in a partially constructed state.
3977 */
3978 proc_signalend(p, 0);
3979 }
3980
3981 if (error == 0) {
3982 /*
3983 * We need to initialize the bank context behind the protection of
3984 * the proc_trans lock to prevent a race with exit. We can't do this during
3985 * exec_activate_image because task_bank_init checks entitlements that
3986 * aren't loaded until subsequent calls (including exec_resettextvp).
3987 */
3988 error = proc_transstart(p, 0, 0);
3989
3990 if (error == 0) {
3991 task_bank_init(new_task);
3992 proc_transend(p, 0);
3993 }
3994
3995 #if __arm64__
3996 proc_footprint_entitlement_hacks(p, new_task);
3997 #endif /* __arm64__ */
3998
3999 #if XNU_TARGET_OS_OSX
4000 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4001 if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4002 vm_map_single_jit(get_task_map(new_task));
4003 }
4004 #endif /* XNU_TARGET_OS_OSX */
4005
4006 #if __has_feature(ptrauth_calls)
4007 task_set_pac_exception_fatal_flag(new_task);
4008 #endif /* __has_feature(ptrauth_calls) */
4009 }
4010
4011 /* Inherit task role from old task to new task for exec */
4012 if (error == 0 && !spawn_no_exec) {
4013 proc_inherit_task_role(new_task, old_task);
4014 }
4015
4016 #if CONFIG_ARCADE
4017 if (error == 0) {
4018 /*
4019 * Check to see if we need to trigger an arcade upcall AST now
4020 * that the vnode has been reset on the task.
4021 */
4022 arcade_prepare(new_task, imgp->ip_new_thread);
4023 }
4024 #endif /* CONFIG_ARCADE */
4025
4026 /* Clear the initial wait on the thread before handling spawn policy */
4027 if (imgp && imgp->ip_new_thread) {
4028 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4029 }
4030
4031 /*
4032 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4033 * and bind any portwatch ports to the new task.
4034 * This must be done after the exec so that the child's thread is ready,
4035 * and after the in transit state has been released, because priority is
4036 * dropped here so we need to be prepared for a potentially long preemption interval
4037 *
4038 * TODO: Consider splitting this up into separate phases
4039 */
4040 if (error == 0 && imgp->ip_px_sa != NULL) {
4041 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4042
4043 error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4044 psa->psa_darwin_role, &port_actions);
4045 }
4046
4047 /* Transfer the turnstile watchport boost to new task if in exec */
4048 if (error == 0 && !spawn_no_exec) {
4049 task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4050 }
4051
4052 /*
4053 * Apply the requested maximum address.
4054 */
4055 if (error == 0 && imgp->ip_px_sa != NULL) {
4056 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4057
4058 if (psa->psa_max_addr) {
4059 vm_map_set_max_addr(get_task_map(new_task), (vm_map_offset_t)psa->psa_max_addr);
4060 }
4061 }
4062
4063 if (error == 0 && imgp->ip_px_sa != NULL) {
4064 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4065
4066 if (psa->psa_no_smt) {
4067 task_set_no_smt(new_task);
4068 }
4069 if (psa->psa_tecs) {
4070 task_set_tecs(new_task);
4071 }
4072 }
4073
4074 if (error == 0) {
4075 /* Apply the main thread qos */
4076 thread_t main_thread = imgp->ip_new_thread;
4077 task_set_main_thread_qos(new_task, main_thread);
4078
4079 #if CONFIG_MACF
4080 proc_apply_jit_and_jumbo_va_policies(p, new_task);
4081 #endif /* CONFIG_MACF */
4082 }
4083
4084 /*
4085 * Release any ports we kept around for binding to the new task
4086 * We need to release the rights even if the posix_spawn has failed.
4087 */
4088 if (imgp->ip_px_spa != NULL) {
4089 exec_port_actions_destroy(&port_actions);
4090 }
4091
4092 /*
4093 * We have to delay operations which might throw a signal until after
4094 * the signals have been unblocked; however, we want that to happen
4095 * after exec_resettextvp() so that the textvp is correct when they
4096 * fire.
4097 */
4098 if (error == 0) {
4099 error = check_for_signature(p, imgp);
4100
4101 /*
4102 * Pay for our earlier safety; deliver the delayed signals from
4103 * the incomplete spawn process now that it's complete.
4104 */
4105 if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4106 psignal_vfork(p, p->task, imgp->ip_new_thread, SIGTRAP);
4107 }
4108
4109 if (error == 0 && !spawn_no_exec) {
4110 KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4111 proc_getpid(p));
4112 }
4113 }
4114
4115 if (spawn_no_exec) {
4116 /* flag the 'fork' has occurred */
4117 proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4118 }
4119
4120 /* flag exec has occurred, notify only if it has not failed due to FP Key error */
4121 if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4122 proc_knote(p, NOTE_EXEC);
4123 }
4124
4125 if (imgp != NULL) {
4126 if (imgp->ip_vp) {
4127 vnode_put(imgp->ip_vp);
4128 }
4129 if (imgp->ip_scriptvp) {
4130 vnode_put(imgp->ip_scriptvp);
4131 }
4132 if (imgp->ip_strings) {
4133 execargs_free(imgp);
4134 }
4135 kfree_data(imgp->ip_px_sfa,
4136 px_args.file_actions_size);
4137 kfree_data(imgp->ip_px_spa,
4138 px_args.port_actions_size);
4139 #if CONFIG_PERSONAS
4140 kfree_data(imgp->ip_px_persona,
4141 px_args.persona_info_size);
4142 #endif
4143 kfree_data(imgp->ip_px_pcred_info,
4144 px_args.posix_cred_info_size);
4145
4146 if (subsystem_root_path != NULL) {
4147 zfree(ZV_NAMEI, subsystem_root_path);
4148 }
4149 #if CONFIG_MACF
4150 struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
4151 kfree_data(px_s->array, px_args.mac_extensions_size);
4152 kfree_data(px_s->data, (vm_size_t)px_s->datalen);
4153
4154 if (imgp->ip_execlabelp) {
4155 mac_cred_label_free(imgp->ip_execlabelp);
4156 imgp->ip_execlabelp = NULL;
4157 }
4158 if (imgp->ip_scriptlabelp) {
4159 mac_vnode_label_free(imgp->ip_scriptlabelp);
4160 imgp->ip_scriptlabelp = NULL;
4161 }
4162 if (imgp->ip_cs_error != OS_REASON_NULL) {
4163 os_reason_free(imgp->ip_cs_error);
4164 imgp->ip_cs_error = OS_REASON_NULL;
4165 }
4166 if (imgp->ip_inherited_shared_region_id != NULL) {
4167 kfree_data(imgp->ip_inherited_shared_region_id,
4168 strlen(imgp->ip_inherited_shared_region_id) + 1);
4169 imgp->ip_inherited_shared_region_id = NULL;
4170 }
4171 #endif
4172 }
4173
4174 #if CONFIG_DTRACE
4175 if (spawn_no_exec) {
4176 /*
4177 * In the original DTrace reference implementation,
4178 * posix_spawn() was a libc routine that just
4179 * did vfork(2) then exec(2). Thus the proc::: probes
4180 * are very fork/exec oriented. The details of this
4181 * in-kernel implementation of posix_spawn() is different
4182 * (while producing the same process-observable effects)
4183 * particularly w.r.t. errors, and which thread/process
4184 * is constructing what on behalf of whom.
4185 */
4186 if (error) {
4187 DTRACE_PROC1(spawn__failure, int, error);
4188 } else {
4189 DTRACE_PROC(spawn__success);
4190 /*
4191 * Some DTrace scripts, e.g. newproc.d in
4192 * /usr/bin, rely on the the 'exec-success'
4193 * probe being fired in the child after the
4194 * new process image has been constructed
4195 * in order to determine the associated pid.
4196 *
4197 * So, even though the parent built the image
4198 * here, for compatibility, mark the new thread
4199 * so 'exec-success' fires on it as it leaves
4200 * the kernel.
4201 */
4202 dtrace_thread_didexec(imgp->ip_new_thread);
4203 }
4204 } else {
4205 if (error) {
4206 DTRACE_PROC1(exec__failure, int, error);
4207 } else {
4208 dtrace_thread_didexec(imgp->ip_new_thread);
4209 }
4210 }
4211
4212 if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4213 (*dtrace_proc_waitfor_hook)(p);
4214 }
4215 #endif
4216
4217 #if CONFIG_AUDIT
4218 if (!error && AUDIT_ENABLED() && p) {
4219 /* Add the CDHash of the new process to the audit record */
4220 uint8_t *cdhash = cs_get_cdhash(p);
4221 if (cdhash) {
4222 AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4223 }
4224 }
4225 #endif
4226
4227 /*
4228 * clear bsd_info from old task if it did exec.
4229 */
4230 if (task_did_exec(old_task)) {
4231 set_bsdtask_info(old_task, NULL);
4232 clear_thread_ro_proc(get_machthread(uthread));
4233 }
4234
4235 /* clear bsd_info from new task and terminate it if exec failed */
4236 if (new_task != NULL && task_is_exec_copy(new_task)) {
4237 set_bsdtask_info(new_task, NULL);
4238 task_terminate_internal(new_task);
4239 if (imgp && imgp->ip_new_thread) {
4240 clear_thread_ro_proc(imgp->ip_new_thread);
4241 }
4242 }
4243
4244 /* Return to both the parent and the child? */
4245 if (imgp != NULL && spawn_no_exec) {
4246 /*
4247 * If the parent wants the pid, copy it out
4248 */
4249 if (pid != USER_ADDR_NULL) {
4250 _Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
4251 bool aligned = (pid & 3) == 0;
4252 if (aligned) {
4253 (void)copyout_atomic32(proc_getpid(p), pid);
4254 } else {
4255 (void)suword(pid, proc_getpid(p));
4256 }
4257 }
4258 retval[0] = error;
4259
4260 /*
4261 * If we had an error, perform an internal reap ; this is
4262 * entirely safe, as we have a real process backing us.
4263 */
4264 if (error) {
4265 proc_list_lock();
4266 p->p_listflag |= P_LIST_DEADPARENT;
4267 proc_list_unlock();
4268 proc_lock(p);
4269 /* make sure no one else has killed it off... */
4270 if (p->p_stat != SZOMB && p->exit_thread == NULL) {
4271 p->exit_thread = current_thread();
4272 proc_unlock(p);
4273 exit1(p, 1, (int *)NULL);
4274 } else {
4275 /* someone is doing it for us; just skip it */
4276 proc_unlock(p);
4277 }
4278 }
4279 }
4280
4281 /*
4282 * Do not terminate the current task, if proc_exec_switch_task did not
4283 * switch the tasks, terminating the current task without the switch would
4284 * result in loosing the SIGKILL status.
4285 */
4286 if (task_did_exec(old_task)) {
4287 /* Terminate the current task, since exec will start in new task */
4288 task_terminate_internal(old_task);
4289 }
4290
4291 /* Release the thread ref returned by fork_create_child/fork1 */
4292 if (imgp != NULL && imgp->ip_new_thread) {
4293 /* wake up the new thread */
4294 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4295 thread_deallocate(imgp->ip_new_thread);
4296 imgp->ip_new_thread = NULL;
4297 }
4298
4299 /* Release the ref returned by fork_create_child/fork1 */
4300 if (new_task) {
4301 task_deallocate(new_task);
4302 new_task = NULL;
4303 }
4304
4305 if (should_release_proc_ref) {
4306 proc_rele(p);
4307 }
4308
4309 kfree_type(typeof(*__spawn_data), __spawn_data);
4310
4311 if (inherit != NULL) {
4312 ipc_importance_release(inherit);
4313 }
4314
4315 return error;
4316 }
4317
4318 /*
4319 * proc_exec_switch_task
4320 *
4321 * Parameters: p proc
4322 * old_task task before exec
4323 * new_task task after exec
4324 * new_thread thread in new task
4325 * inherit resulting importance linkage
4326 *
4327 * Returns: proc.
4328 *
4329 * Note: The function will switch the task pointer of proc
4330 * from old task to new task. The switch needs to happen
4331 * after draining all proc refs and inside a proc translock.
4332 * In the case of failure to switch the task, which might happen
4333 * if the process received a SIGKILL or jetsam killed it, it will make
4334 * sure that the new tasks terminates. User proc ref returned
4335 * to caller.
4336 *
4337 * This function is called after point of no return, in the case
4338 * failure to switch, it will terminate the new task and swallow the
4339 * error and let the terminated process complete exec and die.
4340 */
4341 proc_t
proc_exec_switch_task(proc_t p,task_t old_task,task_t new_task,thread_t new_thread,void ** inherit)4342 proc_exec_switch_task(proc_t p, task_t old_task, task_t new_task, thread_t new_thread,
4343 void **inherit)
4344 {
4345 int error = 0;
4346 boolean_t task_active;
4347 boolean_t proc_active;
4348 boolean_t thread_active;
4349 thread_t old_thread = current_thread();
4350
4351 /*
4352 * Switch the task pointer of proc to new task.
4353 * Before switching the task, wait for proc_refdrain.
4354 * After the switch happens, the proc can disappear,
4355 * take a ref before it disappears. Waiting for
4356 * proc_refdrain in exec will block all other threads
4357 * trying to take a proc ref, boost the current thread
4358 * to avoid priority inversion.
4359 */
4360 thread_set_exec_promotion(old_thread);
4361 p = proc_refdrain_will_exec(p);
4362 /* extra proc ref returned to the caller */
4363
4364 assert(get_threadtask(new_thread) == new_task);
4365 task_active = task_is_active(new_task);
4366
4367 /* Take the proc_translock to change the task ptr */
4368 proc_lock(p);
4369 proc_active = !(p->p_lflag & P_LEXIT);
4370
4371 /* Check if the current thread is not aborted due to SIGKILL */
4372 thread_active = thread_is_active(old_thread);
4373
4374 /*
4375 * Do not switch the task if the new task or proc is already terminated
4376 * as a result of error in exec past point of no return
4377 */
4378 if (proc_active && task_active && thread_active) {
4379 error = proc_transstart(p, 1, 0);
4380 if (error == 0) {
4381 uthread_t new_uthread = get_bsdthread_info(new_thread);
4382 uthread_t old_uthread = current_uthread();
4383
4384 /*
4385 * bsd_info of old_task will get cleared in execve and posix_spawn
4386 * after firing exec-success/error dtrace probe.
4387 */
4388 proc_set_task(p, new_task);
4389 proc_switch_ro(p, task_get_ro(new_task));
4390
4391 /* Clear dispatchqueue and workloop ast offset */
4392 p->p_dispatchqueue_offset = 0;
4393 p->p_dispatchqueue_serialno_offset = 0;
4394 p->p_dispatchqueue_label_offset = 0;
4395 p->p_return_to_kernel_offset = 0;
4396 p->p_pthread_wq_quantum_offset = 0;
4397
4398 /* Copy the signal state, dtrace state and set bsd ast on new thread */
4399 act_set_astbsd(new_thread);
4400 new_uthread->uu_siglist = old_uthread->uu_siglist;
4401 new_uthread->uu_sigwait = old_uthread->uu_sigwait;
4402 new_uthread->uu_sigmask = old_uthread->uu_sigmask;
4403 new_uthread->uu_oldmask = old_uthread->uu_oldmask;
4404 new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
4405 #if CONFIG_DTRACE
4406 new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
4407 new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
4408 new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
4409 assert(new_uthread->t_dtrace_scratch == NULL);
4410 new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
4411
4412 old_uthread->t_dtrace_sig = 0;
4413 old_uthread->t_dtrace_stop = 0;
4414 old_uthread->t_dtrace_resumepid = 0;
4415 old_uthread->t_dtrace_scratch = NULL;
4416 #endif
4417 /* Copy the resource accounting info */
4418 thread_copy_resource_info(new_thread, current_thread());
4419
4420 /* Clear the exit reason and signal state on old thread */
4421 old_uthread->uu_exit_reason = NULL;
4422 old_uthread->uu_siglist = 0;
4423
4424 /* Add the new uthread to proc uthlist and remove the old one */
4425 TAILQ_REMOVE(&p->p_uthlist, old_uthread, uu_list);
4426 assert(TAILQ_EMPTY(&p->p_uthlist));
4427 TAILQ_INSERT_TAIL(&p->p_uthlist, new_uthread, uu_list);
4428
4429 task_set_did_exec_flag(old_task);
4430 task_clear_exec_copy_flag(new_task);
4431
4432 task_copy_fields_for_exec(new_task, old_task);
4433
4434 /* Transfer sandbox filter bits to new_task. */
4435 task_transfer_mach_filter_bits(new_task, old_task);
4436
4437 /*
4438 * Need to transfer pending watch port boosts to the new task
4439 * while still making sure that the old task remains in the
4440 * importance linkage. Create an importance linkage from old task
4441 * to new task, then switch the task importance base of old task
4442 * and new task. After the switch the port watch boost will be
4443 * boosting the new task and new task will be donating importance
4444 * to old task.
4445 */
4446 *inherit = ipc_importance_exec_switch_task(old_task, new_task);
4447
4448 proc_transend(p, 1);
4449 }
4450 }
4451
4452 proc_unlock(p);
4453 proc_refwake_did_exec(p);
4454 thread_clear_exec_promotion(old_thread);
4455
4456 if (error != 0 || !task_active || !proc_active || !thread_active) {
4457 task_terminate_internal(new_task);
4458 }
4459
4460 return p;
4461 }
4462
4463 /*
4464 * execve
4465 *
4466 * Parameters: uap->fname File name to exec
4467 * uap->argp Argument list
4468 * uap->envp Environment list
4469 *
4470 * Returns: 0 Success
4471 * __mac_execve:EINVAL Invalid argument
4472 * __mac_execve:ENOTSUP Invalid argument
4473 * __mac_execve:EACCES Permission denied
4474 * __mac_execve:EINTR Interrupted function
4475 * __mac_execve:ENOMEM Not enough space
4476 * __mac_execve:EFAULT Bad address
4477 * __mac_execve:ENAMETOOLONG Filename too long
4478 * __mac_execve:ENOEXEC Executable file format error
4479 * __mac_execve:ETXTBSY Text file busy [misuse of error code]
4480 * __mac_execve:???
4481 *
4482 * TODO: Dynamic linker header address on stack is copied via suword()
4483 */
4484 /* ARGSUSED */
4485 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)4486 execve(proc_t p, struct execve_args *uap, int32_t *retval)
4487 {
4488 struct __mac_execve_args muap;
4489 int err;
4490
4491 memoryshot(VM_EXECVE, DBG_FUNC_NONE);
4492
4493 muap.fname = uap->fname;
4494 muap.argp = uap->argp;
4495 muap.envp = uap->envp;
4496 muap.mac_p = USER_ADDR_NULL;
4497 err = __mac_execve(p, &muap, retval);
4498
4499 return err;
4500 }
4501
4502 /*
4503 * __mac_execve
4504 *
4505 * Parameters: uap->fname File name to exec
4506 * uap->argp Argument list
4507 * uap->envp Environment list
4508 * uap->mac_p MAC label supplied by caller
4509 *
4510 * Returns: 0 Success
4511 * EINVAL Invalid argument
4512 * ENOTSUP Not supported
4513 * ENOEXEC Executable file format error
4514 * exec_activate_image:EINVAL Invalid argument
4515 * exec_activate_image:EACCES Permission denied
4516 * exec_activate_image:EINTR Interrupted function
4517 * exec_activate_image:ENOMEM Not enough space
4518 * exec_activate_image:EFAULT Bad address
4519 * exec_activate_image:ENAMETOOLONG Filename too long
4520 * exec_activate_image:ENOEXEC Executable file format error
4521 * exec_activate_image:ETXTBSY Text file busy [misuse of error code]
4522 * exec_activate_image:EBADEXEC The executable is corrupt/unknown
4523 * exec_activate_image:???
4524 * mac_execve_enter:???
4525 *
4526 * TODO: Dynamic linker header address on stack is copied via suword()
4527 */
4528 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)4529 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
4530 {
4531 struct image_params *imgp = NULL;
4532 struct vnode_attr *vap = NULL;
4533 struct vnode_attr *origvap = NULL;
4534 int error;
4535 int is_64 = IS_64BIT_PROCESS(p);
4536 struct vfs_context context;
4537 struct uthread *uthread = NULL;
4538 task_t old_task = current_task();
4539 task_t new_task = NULL;
4540 boolean_t should_release_proc_ref = FALSE;
4541 boolean_t exec_done = FALSE;
4542 const bool in_vfexec = false;
4543 void *inherit = NULL;
4544 struct {
4545 struct image_params imgp;
4546 struct vnode_attr va;
4547 struct vnode_attr origva;
4548 } *__execve_data;
4549
4550 context.vc_thread = current_thread();
4551 context.vc_ucred = kauth_cred_proc_ref(p); /* XXX must NOT be kauth_cred_get() */
4552
4553 /* Allocate a big chunk for locals instead of using stack since these
4554 * structures a pretty big.
4555 */
4556 __execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
4557 if (__execve_data == NULL) {
4558 error = ENOMEM;
4559 goto exit_with_error;
4560 }
4561 imgp = &__execve_data->imgp;
4562 vap = &__execve_data->va;
4563 origvap = &__execve_data->origva;
4564
4565 /* Initialize the common data in the image_params structure */
4566 imgp->ip_user_fname = uap->fname;
4567 imgp->ip_user_argv = uap->argp;
4568 imgp->ip_user_envv = uap->envp;
4569 imgp->ip_vattr = vap;
4570 imgp->ip_origvattr = origvap;
4571 imgp->ip_vfs_context = &context;
4572 imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
4573 imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
4574 imgp->ip_mac_return = 0;
4575 imgp->ip_cs_error = OS_REASON_NULL;
4576 imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
4577 imgp->ip_subsystem_root_path = NULL;
4578
4579 #if CONFIG_MACF
4580 if (uap->mac_p != USER_ADDR_NULL) {
4581 error = mac_execve_enter(uap->mac_p, imgp);
4582 if (error) {
4583 kauth_cred_unref(&context.vc_ucred);
4584 goto exit_with_error;
4585 }
4586 }
4587 #endif
4588 uthread = current_uthread();
4589 {
4590 imgp->ip_flags |= IMGPF_EXEC;
4591
4592 /*
4593 * For execve case, create a new task and thread
4594 * which points to current_proc. The current_proc will point
4595 * to the new task after image activation and proc ref drain.
4596 *
4597 * proc (current_proc) <----- old_task (current_task)
4598 * ^ | ^
4599 * | | |
4600 * | ----------------------------------
4601 * |
4602 * --------- new_task (task marked as TF_EXEC_COPY)
4603 *
4604 * After image activation, the proc will point to the new task
4605 * and would look like following.
4606 *
4607 * proc (current_proc) <----- old_task (current_task, marked as TPF_DID_EXEC)
4608 * ^ |
4609 * | |
4610 * | ----------> new_task
4611 * | |
4612 * -----------------
4613 *
4614 * During exec any transition from new_task -> proc is fine, but don't allow
4615 * transition from proc->task, since it will modify old_task.
4616 */
4617 imgp->ip_new_thread = fork_create_child(old_task,
4618 NULL,
4619 p,
4620 FALSE,
4621 p->p_flag & P_LP64,
4622 task_get_64bit_data(old_task),
4623 TRUE);
4624 /* task and thread ref returned by fork_create_child */
4625 if (imgp->ip_new_thread == NULL) {
4626 error = ENOMEM;
4627 goto exit_with_error;
4628 }
4629
4630 new_task = get_threadtask(imgp->ip_new_thread);
4631 context.vc_thread = imgp->ip_new_thread;
4632 }
4633
4634 imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4635
4636 error = exec_activate_image(imgp);
4637 /* thread and task ref returned for vfexec case */
4638
4639 if (imgp->ip_new_thread != NULL) {
4640 /*
4641 * task reference might be returned by exec_activate_image
4642 * for vfexec.
4643 */
4644 new_task = get_threadtask(imgp->ip_new_thread);
4645 #if defined(HAS_APPLE_PAC)
4646 ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
4647 ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
4648 #endif
4649 }
4650
4651 if (!error && !in_vfexec) {
4652 p = proc_exec_switch_task(p, old_task, new_task, imgp->ip_new_thread, &inherit);
4653 /* proc ref returned */
4654 should_release_proc_ref = TRUE;
4655 }
4656
4657 kauth_cred_unref(&context.vc_ucred);
4658
4659 if (!error) {
4660 exec_done = TRUE;
4661 assert(imgp->ip_new_thread != NULL);
4662
4663 exec_resettextvp(p, imgp);
4664 error = check_for_signature(p, imgp);
4665 }
4666
4667 #if defined(HAS_APPLE_PAC)
4668 if (imgp->ip_new_thread && !error) {
4669 ml_task_set_jop_pid_from_shared_region(new_task);
4670 ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4671 }
4672 #endif /* defined(HAS_APPLE_PAC) */
4673
4674 /* flag exec has occurred, notify only if it has not failed due to FP Key error */
4675 if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4676 proc_knote(p, NOTE_EXEC);
4677 }
4678
4679 if (imgp->ip_vp != NULLVP) {
4680 vnode_put(imgp->ip_vp);
4681 }
4682 if (imgp->ip_scriptvp != NULLVP) {
4683 vnode_put(imgp->ip_scriptvp);
4684 }
4685 if (imgp->ip_strings) {
4686 execargs_free(imgp);
4687 }
4688 #if CONFIG_MACF
4689 if (imgp->ip_execlabelp) {
4690 mac_cred_label_free(imgp->ip_execlabelp);
4691 imgp->ip_execlabelp = NULL;
4692 }
4693 if (imgp->ip_scriptlabelp) {
4694 mac_vnode_label_free(imgp->ip_scriptlabelp);
4695 imgp->ip_scriptlabelp = NULL;
4696 }
4697 #endif
4698 if (imgp->ip_cs_error != OS_REASON_NULL) {
4699 os_reason_free(imgp->ip_cs_error);
4700 imgp->ip_cs_error = OS_REASON_NULL;
4701 }
4702
4703 if (!error) {
4704 /*
4705 * We need to initialize the bank context behind the protection of
4706 * the proc_trans lock to prevent a race with exit. We can't do this during
4707 * exec_activate_image because task_bank_init checks entitlements that
4708 * aren't loaded until subsequent calls (including exec_resettextvp).
4709 */
4710 error = proc_transstart(p, 0, 0);
4711 }
4712
4713 if (!error) {
4714 task_bank_init(new_task);
4715 proc_transend(p, 0);
4716
4717 #if __arm64__
4718 proc_footprint_entitlement_hacks(p, new_task);
4719 #endif /* __arm64__ */
4720
4721 #if XNU_TARGET_OS_OSX
4722 if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4723 vm_map_single_jit(get_task_map(new_task));
4724 }
4725 #endif /* XNU_TARGET_OS_OSX */
4726
4727 /* Sever any extant thread affinity */
4728 thread_affinity_exec(current_thread());
4729
4730 /* Inherit task role from old task to new task for exec */
4731 if (!in_vfexec) {
4732 proc_inherit_task_role(new_task, old_task);
4733 }
4734
4735 thread_t main_thread = imgp->ip_new_thread;
4736
4737 task_set_main_thread_qos(new_task, main_thread);
4738
4739 #if __has_feature(ptrauth_calls)
4740 task_set_pac_exception_fatal_flag(new_task);
4741 #endif /* __has_feature(ptrauth_calls) */
4742
4743 #if CONFIG_ARCADE
4744 /*
4745 * Check to see if we need to trigger an arcade upcall AST now
4746 * that the vnode has been reset on the task.
4747 */
4748 arcade_prepare(new_task, imgp->ip_new_thread);
4749 #endif /* CONFIG_ARCADE */
4750
4751 #if CONFIG_MACF
4752 proc_apply_jit_and_jumbo_va_policies(p, new_task);
4753 #endif /* CONFIG_MACF */
4754
4755 if (vm_darkwake_mode == TRUE) {
4756 /*
4757 * This process is being launched when the system
4758 * is in darkwake. So mark it specially. This will
4759 * cause all its pages to be entered in the background Q.
4760 */
4761 task_set_darkwake_mode(new_task, vm_darkwake_mode);
4762 }
4763
4764 #if CONFIG_DTRACE
4765 dtrace_thread_didexec(imgp->ip_new_thread);
4766
4767 if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4768 (*dtrace_proc_waitfor_hook)(p);
4769 }
4770 #endif
4771
4772 #if CONFIG_AUDIT
4773 if (!error && AUDIT_ENABLED() && p) {
4774 /* Add the CDHash of the new process to the audit record */
4775 uint8_t *cdhash = cs_get_cdhash(p);
4776 if (cdhash) {
4777 AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4778 }
4779 }
4780 #endif
4781 } else {
4782 DTRACE_PROC1(exec__failure, int, error);
4783 }
4784
4785 exit_with_error:
4786
4787 /*
4788 * clear bsd_info from old task if it did exec.
4789 */
4790 if (task_did_exec(old_task)) {
4791 set_bsdtask_info(old_task, NULL);
4792 clear_thread_ro_proc(get_machthread(uthread));
4793 }
4794
4795 /* clear bsd_info from new task and terminate it if exec failed */
4796 if (new_task != NULL && task_is_exec_copy(new_task)) {
4797 set_bsdtask_info(new_task, NULL);
4798 if (imgp && imgp->ip_new_thread) {
4799 clear_thread_ro_proc(imgp->ip_new_thread);
4800 }
4801 task_terminate_internal(new_task);
4802 }
4803
4804 if (imgp != NULL) {
4805 /* Clear the initial wait on the thread transferring watchports */
4806 if (imgp->ip_new_thread) {
4807 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4808 }
4809
4810 /* Transfer the watchport boost to new task */
4811 if (!error && !in_vfexec) {
4812 task_transfer_turnstile_watchports(old_task,
4813 new_task, imgp->ip_new_thread);
4814 }
4815 /*
4816 * Do not terminate the current task, if proc_exec_switch_task did not
4817 * switch the tasks, terminating the current task without the switch would
4818 * result in loosing the SIGKILL status.
4819 */
4820 if (task_did_exec(old_task)) {
4821 /* Terminate the current task, since exec will start in new task */
4822 task_terminate_internal(old_task);
4823 }
4824
4825 /* Release the thread ref returned by fork_create_child */
4826 if (imgp->ip_new_thread) {
4827 /* wake up the new exec thread */
4828 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4829 thread_deallocate(imgp->ip_new_thread);
4830 imgp->ip_new_thread = NULL;
4831 }
4832 }
4833
4834 /* Release the ref returned by fork_create_child */
4835 if (new_task) {
4836 task_deallocate(new_task);
4837 new_task = NULL;
4838 }
4839
4840 if (should_release_proc_ref) {
4841 proc_rele(p);
4842 }
4843
4844 kfree_type(typeof(*__execve_data), __execve_data);
4845
4846 if (inherit != NULL) {
4847 ipc_importance_release(inherit);
4848 }
4849
4850 return error;
4851 }
4852
4853
4854 /*
4855 * copyinptr
4856 *
4857 * Description: Copy a pointer in from user space to a user_addr_t in kernel
4858 * space, based on 32/64 bitness of the user space
4859 *
4860 * Parameters: froma User space address
4861 * toptr Address of kernel space user_addr_t
4862 * ptr_size 4/8, based on 'froma' address space
4863 *
4864 * Returns: 0 Success
4865 * EFAULT Bad 'froma'
4866 *
4867 * Implicit returns:
4868 * *ptr_size Modified
4869 */
4870 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)4871 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
4872 {
4873 int error;
4874
4875 if (ptr_size == 4) {
4876 /* 64 bit value containing 32 bit address */
4877 unsigned int i = 0;
4878
4879 error = copyin(froma, &i, 4);
4880 *toptr = CAST_USER_ADDR_T(i); /* SAFE */
4881 } else {
4882 error = copyin(froma, toptr, 8);
4883 }
4884 return error;
4885 }
4886
4887
4888 /*
4889 * copyoutptr
4890 *
4891 * Description: Copy a pointer out from a user_addr_t in kernel space to
4892 * user space, based on 32/64 bitness of the user space
4893 *
4894 * Parameters: ua User space address to copy to
4895 * ptr Address of kernel space user_addr_t
4896 * ptr_size 4/8, based on 'ua' address space
4897 *
4898 * Returns: 0 Success
4899 * EFAULT Bad 'ua'
4900 *
4901 */
4902 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)4903 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
4904 {
4905 int error;
4906
4907 if (ptr_size == 4) {
4908 /* 64 bit value containing 32 bit address */
4909 unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua); /* SAFE */
4910
4911 error = copyout(&i, ptr, 4);
4912 } else {
4913 error = copyout(&ua, ptr, 8);
4914 }
4915 return error;
4916 }
4917
4918
4919 /*
4920 * exec_copyout_strings
4921 *
4922 * Copy out the strings segment to user space. The strings segment is put
4923 * on a preinitialized stack frame.
4924 *
4925 * Parameters: struct image_params * the image parameter block
4926 * int * a pointer to the stack offset variable
4927 *
4928 * Returns: 0 Success
4929 * !0 Faiure: errno
4930 *
4931 * Implicit returns:
4932 * (*stackp) The stack offset, modified
4933 *
4934 * Note: The strings segment layout is backward, from the beginning
4935 * of the top of the stack to consume the minimal amount of
4936 * space possible; the returned stack pointer points to the
4937 * end of the area consumed (stacks grow downward).
4938 *
4939 * argc is an int; arg[i] are pointers; env[i] are pointers;
4940 * the 0's are (void *)NULL's
4941 *
4942 * The stack frame layout is:
4943 *
4944 * +-------------+ <- p->user_stack
4945 * | 16b |
4946 * +-------------+
4947 * | STRING AREA |
4948 * | : |
4949 * | : |
4950 * | : |
4951 * +- -- -- -- --+
4952 * | PATH AREA |
4953 * +-------------+
4954 * | 0 |
4955 * +-------------+
4956 * | applev[n] |
4957 * +-------------+
4958 * :
4959 * :
4960 * +-------------+
4961 * | applev[1] |
4962 * +-------------+
4963 * | exec_path / |
4964 * | applev[0] |
4965 * +-------------+
4966 * | 0 |
4967 * +-------------+
4968 * | env[n] |
4969 * +-------------+
4970 * :
4971 * :
4972 * +-------------+
4973 * | env[0] |
4974 * +-------------+
4975 * | 0 |
4976 * +-------------+
4977 * | arg[argc-1] |
4978 * +-------------+
4979 * :
4980 * :
4981 * +-------------+
4982 * | arg[0] |
4983 * +-------------+
4984 * | argc |
4985 * sp-> +-------------+
4986 *
4987 * Although technically a part of the STRING AREA, we treat the PATH AREA as
4988 * a separate entity. This allows us to align the beginning of the PATH AREA
4989 * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
4990 * which preceed it on the stack are properly aligned.
4991 */
4992 __attribute__((noinline))
4993 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)4994 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
4995 {
4996 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
4997 int ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
4998 int ptr_area_size;
4999 void *ptr_buffer_start, *ptr_buffer;
5000 size_t string_size;
5001
5002 user_addr_t string_area; /* *argv[], *env[] */
5003 user_addr_t ptr_area; /* argv[], env[], applev[] */
5004 user_addr_t argc_area; /* argc */
5005 user_addr_t stack;
5006 int error;
5007
5008 unsigned i;
5009 struct copyout_desc {
5010 char *start_string;
5011 int count;
5012 #if CONFIG_DTRACE
5013 user_addr_t *dtrace_cookie;
5014 #endif
5015 boolean_t null_term;
5016 } descriptors[] = {
5017 {
5018 .start_string = imgp->ip_startargv,
5019 .count = imgp->ip_argc,
5020 #if CONFIG_DTRACE
5021 .dtrace_cookie = &p->p_dtrace_argv,
5022 #endif
5023 .null_term = TRUE
5024 },
5025 {
5026 .start_string = imgp->ip_endargv,
5027 .count = imgp->ip_envc,
5028 #if CONFIG_DTRACE
5029 .dtrace_cookie = &p->p_dtrace_envp,
5030 #endif
5031 .null_term = TRUE
5032 },
5033 {
5034 .start_string = imgp->ip_strings,
5035 .count = 1,
5036 #if CONFIG_DTRACE
5037 .dtrace_cookie = NULL,
5038 #endif
5039 .null_term = FALSE
5040 },
5041 {
5042 .start_string = imgp->ip_endenvv,
5043 .count = imgp->ip_applec - 1, /* exec_path handled above */
5044 #if CONFIG_DTRACE
5045 .dtrace_cookie = NULL,
5046 #endif
5047 .null_term = TRUE
5048 }
5049 };
5050
5051 stack = *stackp;
5052
5053 /*
5054 * All previous contributors to the string area
5055 * should have aligned their sub-area
5056 */
5057 if (imgp->ip_strspace % ptr_size != 0) {
5058 error = EINVAL;
5059 goto bad;
5060 }
5061
5062 /* Grow the stack down for the strings we've been building up */
5063 string_size = imgp->ip_strendp - imgp->ip_strings;
5064 stack -= string_size;
5065 string_area = stack;
5066
5067 /*
5068 * Need room for one pointer for each string, plus
5069 * one for the NULLs terminating the argv, envv, and apple areas.
5070 */
5071 ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5072 stack -= ptr_area_size;
5073 ptr_area = stack;
5074
5075 /* We'll construct all the pointer arrays in our string buffer,
5076 * which we already know is aligned properly, and ip_argspace
5077 * was used to verify we have enough space.
5078 */
5079 ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5080
5081 /*
5082 * Need room for pointer-aligned argc slot.
5083 */
5084 stack -= ptr_size;
5085 argc_area = stack;
5086
5087 /*
5088 * Record the size of the arguments area so that sysctl_procargs()
5089 * can return the argument area without having to parse the arguments.
5090 */
5091 proc_lock(p);
5092 p->p_argc = imgp->ip_argc;
5093 p->p_argslen = (int)(*stackp - string_area);
5094 proc_unlock(p);
5095
5096 /* Return the initial stack address: the location of argc */
5097 *stackp = stack;
5098
5099 /*
5100 * Copy out the entire strings area.
5101 */
5102 error = copyout(imgp->ip_strings, string_area,
5103 string_size);
5104 if (error) {
5105 goto bad;
5106 }
5107
5108 for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
5109 char *cur_string = descriptors[i].start_string;
5110 int j;
5111
5112 #if CONFIG_DTRACE
5113 if (descriptors[i].dtrace_cookie) {
5114 proc_lock(p);
5115 *descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
5116 proc_unlock(p);
5117 }
5118 #endif /* CONFIG_DTRACE */
5119
5120 /*
5121 * For each segment (argv, envv, applev), copy as many pointers as requested
5122 * to our pointer buffer.
5123 */
5124 for (j = 0; j < descriptors[i].count; j++) {
5125 user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
5126
5127 /* Copy out the pointer to the current string. Alignment has been verified */
5128 if (ptr_size == 8) {
5129 *(uint64_t *)ptr_buffer = (uint64_t)cur_address;
5130 } else {
5131 *(uint32_t *)ptr_buffer = (uint32_t)cur_address;
5132 }
5133
5134 ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5135 cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
5136 }
5137
5138 if (descriptors[i].null_term) {
5139 if (ptr_size == 8) {
5140 *(uint64_t *)ptr_buffer = 0ULL;
5141 } else {
5142 *(uint32_t *)ptr_buffer = 0;
5143 }
5144
5145 ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5146 }
5147 }
5148
5149 /*
5150 * Copy out all our pointer arrays in bulk.
5151 */
5152 error = copyout(ptr_buffer_start, ptr_area,
5153 ptr_area_size);
5154 if (error) {
5155 goto bad;
5156 }
5157
5158 /* argc (int32, stored in a ptr_size area) */
5159 error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
5160 if (error) {
5161 goto bad;
5162 }
5163
5164 bad:
5165 return error;
5166 }
5167
5168
5169 /*
5170 * exec_extract_strings
5171 *
5172 * Copy arguments and environment from user space into work area; we may
5173 * have already copied some early arguments into the work area, and if
5174 * so, any arguments opied in are appended to those already there.
5175 * This function is the primary manipulator of ip_argspace, since
5176 * these are the arguments the client of execve(2) knows about. After
5177 * each argv[]/envv[] string is copied, we charge the string length
5178 * and argv[]/envv[] pointer slot to ip_argspace, so that we can
5179 * full preflight the arg list size.
5180 *
5181 * Parameters: struct image_params * the image parameter block
5182 *
5183 * Returns: 0 Success
5184 * !0 Failure: errno
5185 *
5186 * Implicit returns;
5187 * (imgp->ip_argc) Count of arguments, updated
5188 * (imgp->ip_envc) Count of environment strings, updated
5189 * (imgp->ip_argspace) Count of remaining of NCARGS
5190 * (imgp->ip_interp_buffer) Interpreter and args (mutated in place)
5191 *
5192 *
5193 * Note: The argument and environment vectors are user space pointers
5194 * to arrays of user space pointers.
5195 */
5196 __attribute__((noinline))
5197 static int
exec_extract_strings(struct image_params * imgp)5198 exec_extract_strings(struct image_params *imgp)
5199 {
5200 int error = 0;
5201 int ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
5202 int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5203 user_addr_t argv = imgp->ip_user_argv;
5204 user_addr_t envv = imgp->ip_user_envv;
5205
5206 /*
5207 * Adjust space reserved for the path name by however much padding it
5208 * needs. Doing this here since we didn't know if this would be a 32-
5209 * or 64-bit process back in exec_save_path.
5210 */
5211 while (imgp->ip_strspace % new_ptr_size != 0) {
5212 *imgp->ip_strendp++ = '\0';
5213 imgp->ip_strspace--;
5214 /* imgp->ip_argspace--; not counted towards exec args total */
5215 }
5216
5217 /*
5218 * From now on, we start attributing string space to ip_argspace
5219 */
5220 imgp->ip_startargv = imgp->ip_strendp;
5221 imgp->ip_argc = 0;
5222
5223 if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
5224 user_addr_t arg;
5225 char *argstart, *ch;
5226
5227 /* First, the arguments in the "#!" string are tokenized and extracted. */
5228 argstart = imgp->ip_interp_buffer;
5229 while (argstart) {
5230 ch = argstart;
5231 while (*ch && !IS_WHITESPACE(*ch)) {
5232 ch++;
5233 }
5234
5235 if (*ch == '\0') {
5236 /* last argument, no need to NUL-terminate */
5237 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5238 argstart = NULL;
5239 } else {
5240 /* NUL-terminate */
5241 *ch = '\0';
5242 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5243
5244 /*
5245 * Find the next string. We know spaces at the end of the string have already
5246 * been stripped.
5247 */
5248 argstart = ch + 1;
5249 while (IS_WHITESPACE(*argstart)) {
5250 argstart++;
5251 }
5252 }
5253
5254 /* Error-check, regardless of whether this is the last interpreter arg or not */
5255 if (error) {
5256 goto bad;
5257 }
5258 if (imgp->ip_argspace < new_ptr_size) {
5259 error = E2BIG;
5260 goto bad;
5261 }
5262 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5263 imgp->ip_argc++;
5264 }
5265
5266 if (argv != 0LL) {
5267 /*
5268 * If we are running an interpreter, replace the av[0] that was
5269 * passed to execve() with the path name that was
5270 * passed to execve() for interpreters which do not use the PATH
5271 * to locate their script arguments.
5272 */
5273 error = copyinptr(argv, &arg, ptr_size);
5274 if (error) {
5275 goto bad;
5276 }
5277 if (arg != 0LL) {
5278 argv += ptr_size; /* consume without using */
5279 }
5280 }
5281
5282 if (imgp->ip_interp_sugid_fd != -1) {
5283 char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
5284 snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
5285 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
5286 } else {
5287 error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
5288 }
5289
5290 if (error) {
5291 goto bad;
5292 }
5293 if (imgp->ip_argspace < new_ptr_size) {
5294 error = E2BIG;
5295 goto bad;
5296 }
5297 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5298 imgp->ip_argc++;
5299 }
5300
5301 while (argv != 0LL) {
5302 user_addr_t arg;
5303
5304 error = copyinptr(argv, &arg, ptr_size);
5305 if (error) {
5306 goto bad;
5307 }
5308
5309 if (arg == 0LL) {
5310 break;
5311 }
5312
5313 argv += ptr_size;
5314
5315 /*
5316 * av[n...] = arg[n]
5317 */
5318 error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
5319 if (error) {
5320 goto bad;
5321 }
5322 if (imgp->ip_argspace < new_ptr_size) {
5323 error = E2BIG;
5324 goto bad;
5325 }
5326 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5327 imgp->ip_argc++;
5328 }
5329
5330 /* Save space for argv[] NULL terminator */
5331 if (imgp->ip_argspace < new_ptr_size) {
5332 error = E2BIG;
5333 goto bad;
5334 }
5335 imgp->ip_argspace -= new_ptr_size;
5336
5337 /* Note where the args ends and env begins. */
5338 imgp->ip_endargv = imgp->ip_strendp;
5339 imgp->ip_envc = 0;
5340
5341 /* Now, get the environment */
5342 while (envv != 0LL) {
5343 user_addr_t env;
5344
5345 error = copyinptr(envv, &env, ptr_size);
5346 if (error) {
5347 goto bad;
5348 }
5349
5350 envv += ptr_size;
5351 if (env == 0LL) {
5352 break;
5353 }
5354 /*
5355 * av[n...] = env[n]
5356 */
5357 error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
5358 if (error) {
5359 goto bad;
5360 }
5361 if (imgp->ip_argspace < new_ptr_size) {
5362 error = E2BIG;
5363 goto bad;
5364 }
5365 imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
5366 imgp->ip_envc++;
5367 }
5368
5369 /* Save space for envv[] NULL terminator */
5370 if (imgp->ip_argspace < new_ptr_size) {
5371 error = E2BIG;
5372 goto bad;
5373 }
5374 imgp->ip_argspace -= new_ptr_size;
5375
5376 /* Align the tail of the combined argv+envv area */
5377 while (imgp->ip_strspace % new_ptr_size != 0) {
5378 if (imgp->ip_argspace < 1) {
5379 error = E2BIG;
5380 goto bad;
5381 }
5382 *imgp->ip_strendp++ = '\0';
5383 imgp->ip_strspace--;
5384 imgp->ip_argspace--;
5385 }
5386
5387 /* Note where the envv ends and applev begins. */
5388 imgp->ip_endenvv = imgp->ip_strendp;
5389
5390 /*
5391 * From now on, we are no longer charging argument
5392 * space to ip_argspace.
5393 */
5394
5395 bad:
5396 return error;
5397 }
5398
5399 /*
5400 * Libc has an 8-element array set up for stack guard values. It only fills
5401 * in one of those entries, and both gcc and llvm seem to use only a single
5402 * 8-byte guard. Until somebody needs more than an 8-byte guard value, don't
5403 * do the work to construct them.
5404 */
5405 #define GUARD_VALUES 1
5406 #define GUARD_KEY "stack_guard="
5407
5408 /*
5409 * System malloc needs some entropy when it is initialized.
5410 */
5411 #define ENTROPY_VALUES 2
5412 #define ENTROPY_KEY "malloc_entropy="
5413
5414 /*
5415 * libplatform needs a random pointer-obfuscation value when it is initialized.
5416 */
5417 #define PTR_MUNGE_VALUES 1
5418 #define PTR_MUNGE_KEY "ptr_munge="
5419
5420 /*
5421 * System malloc engages nanozone for UIAPP.
5422 */
5423 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
5424 /*
5425 * Used to pass experiment flags up to libmalloc.
5426 */
5427 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
5428
5429 #define PFZ_KEY "pfz="
5430 extern user32_addr_t commpage_text32_location;
5431 extern user64_addr_t commpage_text64_location;
5432
5433 extern uuid_string_t bootsessionuuid_string;
5434
5435 #define MAIN_STACK_VALUES 4
5436 #define MAIN_STACK_KEY "main_stack="
5437
5438 #define FSID_KEY "executable_file="
5439 #define DYLD_FSID_KEY "dyld_file="
5440 #define CDHASH_KEY "executable_cdhash="
5441 #define DYLD_FLAGS_KEY "dyld_flags="
5442 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
5443 #define APP_BOOT_SESSION_KEY "executable_boothash="
5444 #if __has_feature(ptrauth_calls)
5445 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
5446 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
5447 #endif /* __has_feature(ptrauth_calls) */
5448 #define MAIN_TH_PORT_KEY "th_port="
5449
5450 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
5451
5452 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
5453 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
5454
5455 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
5456 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
5457 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
5458
5459 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)5460 exec_add_entropy_key(struct image_params *imgp,
5461 const char *key,
5462 int values,
5463 boolean_t embedNUL)
5464 {
5465 const int limit = 8;
5466 uint64_t entropy[limit];
5467 char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
5468 if (values > limit) {
5469 values = limit;
5470 }
5471
5472 read_random(entropy, sizeof(entropy[0]) * values);
5473
5474 if (embedNUL) {
5475 entropy[0] &= ~(0xffull << 8);
5476 }
5477
5478 int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
5479 size_t remaining = sizeof(str) - len;
5480 for (int i = 1; i < values && remaining > 0; ++i) {
5481 size_t start = sizeof(str) - remaining;
5482 len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
5483 remaining -= len;
5484 }
5485
5486 return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
5487 }
5488
5489 /*
5490 * Build up the contents of the apple[] string vector
5491 */
5492 #if (DEVELOPMENT || DEBUG)
5493 extern uint64_t dyld_flags;
5494 #endif
5495
5496 #if __has_feature(ptrauth_calls)
5497 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)5498 is_arm64e_running_as_arm64(const struct image_params *imgp)
5499 {
5500 return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
5501 (imgp->ip_flags & IMGPF_NOJOP);
5502 }
5503 #endif /* __has_feature(ptrauth_calls) */
5504
5505 _Atomic uint64_t libmalloc_experiment_factors = 0;
5506
5507 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result)5508 exec_add_apple_strings(struct image_params *imgp,
5509 const load_result_t *load_result)
5510 {
5511 int error;
5512 int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5513 thread_t new_thread;
5514 ipc_port_t sright;
5515 uint64_t local_experiment_factors = 0;
5516
5517 /* exec_save_path stored the first string */
5518 imgp->ip_applec = 1;
5519
5520 /* adding the pfz string */
5521 {
5522 char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
5523
5524 if (img_ptr_size == 8) {
5525 __assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
5526 assert(ret < sizeof(pfz_string));
5527 } else {
5528 snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
5529 }
5530 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
5531 if (error) {
5532 printf("Failed to add the pfz string with error %d\n", error);
5533 goto bad;
5534 }
5535 imgp->ip_applec++;
5536 }
5537
5538 /* adding the NANO_ENGAGE_KEY key */
5539 if (imgp->ip_px_sa) {
5540 int proc_flags = (((struct _posix_spawnattr *) imgp->ip_px_sa)->psa_flags);
5541
5542 if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
5543 const char *nano_string = NANO_ENGAGE_KEY;
5544 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
5545 if (error) {
5546 goto bad;
5547 }
5548 imgp->ip_applec++;
5549 }
5550 }
5551
5552 /*
5553 * Supply libc with a collection of random values to use when
5554 * implementing -fstack-protector.
5555 *
5556 * (The first random string always contains an embedded NUL so that
5557 * __stack_chk_guard also protects against C string vulnerabilities)
5558 */
5559 error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
5560 if (error) {
5561 goto bad;
5562 }
5563 imgp->ip_applec++;
5564
5565 /*
5566 * Supply libc with entropy for system malloc.
5567 */
5568 error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
5569 if (error) {
5570 goto bad;
5571 }
5572 imgp->ip_applec++;
5573
5574 /*
5575 * Supply libpthread & libplatform with a random value to use for pointer
5576 * obfuscation.
5577 */
5578 error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
5579 if (error) {
5580 goto bad;
5581 }
5582 imgp->ip_applec++;
5583
5584 /*
5585 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
5586 * stack if it was allocated by the kernel.
5587 *
5588 * The guard page is not included in this stack size as libpthread
5589 * expects to add it back in after receiving this value.
5590 */
5591 if (load_result->unixproc) {
5592 char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
5593 snprintf(stack_string, sizeof(stack_string),
5594 MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
5595 (uint64_t)load_result->user_stack,
5596 (uint64_t)load_result->user_stack_size,
5597 (uint64_t)load_result->user_stack_alloc,
5598 (uint64_t)load_result->user_stack_alloc_size);
5599 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
5600 if (error) {
5601 goto bad;
5602 }
5603 imgp->ip_applec++;
5604 }
5605
5606 if (imgp->ip_vattr) {
5607 uint64_t fsid = vnode_get_va_fsid(imgp->ip_vattr);
5608 uint64_t fsobjid = imgp->ip_vattr->va_fileid;
5609
5610 char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
5611 snprintf(fsid_string, sizeof(fsid_string),
5612 FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
5613 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
5614 if (error) {
5615 goto bad;
5616 }
5617 imgp->ip_applec++;
5618 }
5619
5620 if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
5621 char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
5622 snprintf(fsid_string, sizeof(fsid_string),
5623 DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
5624 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
5625 if (error) {
5626 goto bad;
5627 }
5628 imgp->ip_applec++;
5629 }
5630
5631 uint8_t cdhash[SHA1_RESULTLEN];
5632 int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash);
5633 if (cdhash_errror == 0) {
5634 char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
5635 strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
5636 char *p = hash_string + sizeof(CDHASH_KEY) - 1;
5637 for (int i = 0; i < SHA1_RESULTLEN; i++) {
5638 snprintf(p, 3, "%02x", (int) cdhash[i]);
5639 p += 2;
5640 }
5641 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
5642 if (error) {
5643 goto bad;
5644 }
5645 imgp->ip_applec++;
5646
5647 /* hash together cd-hash and boot-session-uuid */
5648 uint8_t sha_digest[SHA256_DIGEST_LENGTH];
5649 SHA256_CTX sha_ctx;
5650 SHA256_Init(&sha_ctx);
5651 SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
5652 SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
5653 SHA256_Final(sha_digest, &sha_ctx);
5654 char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
5655 strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
5656 char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
5657 for (int i = 0; i < SHA1_RESULTLEN; i++) {
5658 snprintf(s, 3, "%02x", (int) sha_digest[i]);
5659 s += 2;
5660 }
5661 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
5662 if (error) {
5663 goto bad;
5664 }
5665 imgp->ip_applec++;
5666 }
5667 #if (DEVELOPMENT || DEBUG)
5668 if (dyld_flags) {
5669 char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
5670 snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
5671 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
5672 if (error) {
5673 goto bad;
5674 }
5675 imgp->ip_applec++;
5676 }
5677 #endif
5678 if (imgp->ip_subsystem_root_path) {
5679 size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
5680 char subsystem_root_path_string[buffer_len];
5681 int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
5682
5683 if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
5684 error = ENAMETOOLONG;
5685 goto bad;
5686 }
5687
5688 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
5689 if (error) {
5690 goto bad;
5691 }
5692
5693 imgp->ip_applec++;
5694 }
5695 #if __has_feature(ptrauth_calls)
5696 if (is_arm64e_running_as_arm64(imgp)) {
5697 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
5698 if (error) {
5699 goto bad;
5700 }
5701
5702 imgp->ip_applec++;
5703 }
5704 #endif /* __has_feature(ptrauth_calls) */
5705
5706
5707 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
5708 {
5709 char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
5710 strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
5711 bool allowAll = bootarg_arm64e_preview_abi;
5712 strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
5713 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
5714 if (error) {
5715 goto bad;
5716 }
5717
5718 imgp->ip_applec++;
5719 }
5720 #endif
5721 /*
5722 * Add main thread mach port name
5723 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
5724 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
5725 * against libpthread.
5726 */
5727 if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
5728 thread_reference(new_thread);
5729 sright = convert_thread_to_port_pinned(new_thread);
5730 task_t new_task = get_threadtask(new_thread);
5731 mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
5732 char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
5733 snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
5734
5735 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
5736 if (error) {
5737 goto bad;
5738 }
5739 imgp->ip_applec++;
5740 }
5741
5742 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
5743 if (imgp->ip_px_sa != NULL) {
5744 struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
5745 if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
5746 const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
5747 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
5748 if (error) {
5749 goto bad;
5750 }
5751 imgp->ip_applec++;
5752 }
5753 }
5754 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
5755
5756 /* adding the libmalloc experiment string */
5757 local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
5758 if (__improbable(local_experiment_factors != 0)) {
5759 char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
5760
5761 snprintf(
5762 libmalloc_experiment_factors_string,
5763 sizeof(libmalloc_experiment_factors_string),
5764 LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
5765 local_experiment_factors);
5766 error = exec_add_user_string(
5767 imgp,
5768 CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
5769 UIO_SYSSPACE,
5770 FALSE);
5771 if (error) {
5772 printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
5773 goto bad;
5774 }
5775 imgp->ip_applec++;
5776 }
5777
5778 /* Align the tail of the combined applev area */
5779 while (imgp->ip_strspace % img_ptr_size != 0) {
5780 *imgp->ip_strendp++ = '\0';
5781 imgp->ip_strspace--;
5782 }
5783
5784 bad:
5785 return error;
5786 }
5787
5788 /*
5789 * exec_check_permissions
5790 *
5791 * Description: Verify that the file that is being attempted to be executed
5792 * is in fact allowed to be executed based on it POSIX file
5793 * permissions and other access control criteria
5794 *
5795 * Parameters: struct image_params * the image parameter block
5796 *
5797 * Returns: 0 Success
5798 * EACCES Permission denied
5799 * ENOEXEC Executable file format error
5800 * ETXTBSY Text file busy [misuse of error code]
5801 * vnode_getattr:???
5802 * vnode_authorize:???
5803 */
5804 static int
exec_check_permissions(struct image_params * imgp)5805 exec_check_permissions(struct image_params *imgp)
5806 {
5807 struct vnode *vp = imgp->ip_vp;
5808 struct vnode_attr *vap = imgp->ip_vattr;
5809 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5810 int error;
5811 kauth_action_t action;
5812
5813 /* Only allow execution of regular files */
5814 if (!vnode_isreg(vp)) {
5815 return EACCES;
5816 }
5817
5818 /* Get the file attributes that we will be using here and elsewhere */
5819 VATTR_INIT(vap);
5820 VATTR_WANTED(vap, va_uid);
5821 VATTR_WANTED(vap, va_gid);
5822 VATTR_WANTED(vap, va_mode);
5823 VATTR_WANTED(vap, va_fsid);
5824 VATTR_WANTED(vap, va_fsid64);
5825 VATTR_WANTED(vap, va_fileid);
5826 VATTR_WANTED(vap, va_data_size);
5827 if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
5828 return error;
5829 }
5830
5831 /*
5832 * Ensure that at least one execute bit is on - otherwise root
5833 * will always succeed, and we don't want to happen unless the
5834 * file really is executable.
5835 */
5836 if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
5837 return EACCES;
5838 }
5839
5840 /* Disallow zero length files */
5841 if (vap->va_data_size == 0) {
5842 return ENOEXEC;
5843 }
5844
5845 imgp->ip_arch_offset = (user_size_t)0;
5846 #if __LP64__
5847 imgp->ip_arch_size = vap->va_data_size;
5848 #else
5849 if (vap->va_data_size > UINT32_MAX) {
5850 return ENOEXEC;
5851 }
5852 imgp->ip_arch_size = (user_size_t)vap->va_data_size;
5853 #endif
5854
5855 /* Disable setuid-ness for traced programs or if MNT_NOSUID */
5856 if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
5857 vap->va_mode &= ~(VSUID | VSGID);
5858 }
5859
5860 /*
5861 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
5862 * flags for setuid/setgid binaries.
5863 */
5864 if (vap->va_mode & (VSUID | VSGID)) {
5865 imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
5866 }
5867
5868 #if CONFIG_MACF
5869 error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
5870 if (error) {
5871 return error;
5872 }
5873 #endif
5874
5875 /* Check for execute permission */
5876 action = KAUTH_VNODE_EXECUTE;
5877 /* Traced images must also be readable */
5878 if (p->p_lflag & P_LTRACED) {
5879 action |= KAUTH_VNODE_READ_DATA;
5880 }
5881 if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
5882 return error;
5883 }
5884
5885 #if 0
5886 /* Don't let it run if anyone had it open for writing */
5887 vnode_lock(vp);
5888 if (vp->v_writecount) {
5889 panic("going to return ETXTBSY %x", vp);
5890 vnode_unlock(vp);
5891 return ETXTBSY;
5892 }
5893 vnode_unlock(vp);
5894 #endif
5895
5896 /* XXX May want to indicate to underlying FS that vnode is open */
5897
5898 return error;
5899 }
5900
5901
5902 /*
5903 * exec_handle_sugid
5904 *
5905 * Initially clear the P_SUGID in the process flags; if an SUGID process is
5906 * exec'ing a non-SUGID image, then this is the point of no return.
5907 *
5908 * If the image being activated is SUGID, then replace the credential with a
5909 * copy, disable tracing (unless the tracing process is root), reset the
5910 * mach task port to revoke it, set the P_SUGID bit,
5911 *
5912 * If the saved user and group ID will be changing, then make sure it happens
5913 * to a new credential, rather than a shared one.
5914 *
5915 * Set the security token (this is probably obsolete, given that the token
5916 * should not technically be separate from the credential itself).
5917 *
5918 * Parameters: struct image_params * the image parameter block
5919 *
5920 * Returns: void No failure indication
5921 *
5922 * Implicit returns:
5923 * <process credential> Potentially modified/replaced
5924 * <task port> Potentially revoked
5925 * <process flags> P_SUGID bit potentially modified
5926 * <security token> Potentially modified
5927 */
5928 __attribute__((noinline))
5929 static int
exec_handle_sugid(struct image_params * imgp)5930 exec_handle_sugid(struct image_params *imgp)
5931 {
5932 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5933 kauth_cred_t cred = vfs_context_ucred(imgp->ip_vfs_context);
5934 int i;
5935 int leave_sugid_clear = 0;
5936 int mac_reset_ipc = 0;
5937 int error = 0;
5938 task_t task = NULL;
5939 #if CONFIG_MACF
5940 int mac_transition, disjoint_cred = 0;
5941 int label_update_return = 0;
5942
5943 /*
5944 * Determine whether a call to update the MAC label will result in the
5945 * credential changing.
5946 *
5947 * Note: MAC policies which do not actually end up modifying
5948 * the label subsequently are strongly encouraged to
5949 * return 0 for this check, since a non-zero answer will
5950 * slow down the exec fast path for normal binaries.
5951 */
5952 mac_transition = mac_cred_check_label_update_execve(
5953 imgp->ip_vfs_context,
5954 imgp->ip_vp,
5955 imgp->ip_arch_offset,
5956 imgp->ip_scriptvp,
5957 imgp->ip_scriptlabelp,
5958 imgp->ip_execlabelp,
5959 p,
5960 &imgp->ip_px_smpx);
5961 #endif
5962
5963 OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
5964
5965 /*
5966 * Order of the following is important; group checks must go last,
5967 * as we use the success of the 'ismember' check combined with the
5968 * failure of the explicit match to indicate that we will be setting
5969 * the egid of the process even though the new process did not
5970 * require VSUID/VSGID bits in order for it to set the new group as
5971 * its egid.
5972 *
5973 * Note: Technically, by this we are implying a call to
5974 * setegid() in the new process, rather than implying
5975 * it used its VSGID bit to set the effective group,
5976 * even though there is no code in that process to make
5977 * such a call.
5978 */
5979 if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
5980 kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
5981 ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
5982 ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
5983 (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
5984 #if CONFIG_MACF
5985 /* label for MAC transition and neither VSUID nor VSGID */
5986 handle_mac_transition:
5987 #endif
5988
5989 #if CONFIG_SETUID
5990 /*
5991 * Replace the credential with a copy of itself if euid or
5992 * egid change.
5993 *
5994 * Note: setuid binaries will automatically opt out of
5995 * group resolver participation as a side effect
5996 * of this operation. This is an intentional
5997 * part of the security model, which requires a
5998 * participating credential be established by
5999 * escalating privilege, setting up all other
6000 * aspects of the credential including whether
6001 * or not to participate in external group
6002 * membership resolution, then dropping their
6003 * effective privilege to that of the desired
6004 * final credential state.
6005 *
6006 * Modifications to p_ucred must be guarded using the
6007 * proc's ucred lock. This prevents others from accessing
6008 * a garbage credential.
6009 */
6010
6011 if (imgp->ip_origvattr->va_mode & VSUID) {
6012 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred) {
6013 return kauth_cred_setresuid(my_cred,
6014 KAUTH_UID_NONE,
6015 imgp->ip_origvattr->va_uid,
6016 imgp->ip_origvattr->va_uid,
6017 KAUTH_UID_NONE);
6018 });
6019 }
6020
6021 if (imgp->ip_origvattr->va_mode & VSGID) {
6022 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred) {
6023 return kauth_cred_setresgid(my_cred,
6024 KAUTH_GID_NONE,
6025 imgp->ip_origvattr->va_gid,
6026 imgp->ip_origvattr->va_gid);
6027 });
6028 }
6029 #endif /* CONFIG_SETUID */
6030
6031 #if CONFIG_MACF
6032 /*
6033 * If a policy has indicated that it will transition the label,
6034 * before making the call into the MAC policies, get a new
6035 * duplicate credential, so they can modify it without
6036 * modifying any others sharing it.
6037 */
6038 if (mac_transition) {
6039 /*
6040 * This hook may generate upcalls that require
6041 * importance donation from the kernel.
6042 * (23925818)
6043 */
6044 thread_t thread = current_thread();
6045 thread_enable_send_importance(thread, TRUE);
6046 kauth_proc_label_update_execve(p,
6047 imgp->ip_vfs_context,
6048 imgp->ip_vp,
6049 imgp->ip_arch_offset,
6050 imgp->ip_scriptvp,
6051 imgp->ip_scriptlabelp,
6052 imgp->ip_execlabelp,
6053 &imgp->ip_csflags,
6054 &imgp->ip_px_smpx,
6055 &disjoint_cred, /* will be non zero if disjoint */
6056 &label_update_return);
6057 thread_enable_send_importance(thread, FALSE);
6058
6059 if (disjoint_cred) {
6060 /*
6061 * If updating the MAC label resulted in a
6062 * disjoint credential, flag that we need to
6063 * set the P_SUGID bit. This protects
6064 * against debuggers being attached by an
6065 * insufficiently privileged process onto the
6066 * result of a transition to a more privileged
6067 * credential.
6068 */
6069 leave_sugid_clear = 0;
6070 }
6071
6072 imgp->ip_mac_return = label_update_return;
6073 }
6074
6075 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);
6076
6077 #endif /* CONFIG_MACF */
6078
6079 /*
6080 * If 'leave_sugid_clear' is non-zero, then we passed the
6081 * VSUID and MACF checks, and successfully determined that
6082 * the previous cred was a member of the VSGID group, but
6083 * that it was not the default at the time of the execve,
6084 * and that the post-labelling credential was not disjoint.
6085 * So we don't set the P_SUGID or reset mach ports and fds
6086 * on the basis of simply running this code.
6087 */
6088 if (mac_reset_ipc || !leave_sugid_clear) {
6089 /*
6090 * Have mach reset the task and thread ports.
6091 * We don't want anyone who had the ports before
6092 * a setuid exec to be able to access/control the
6093 * task/thread after.
6094 */
6095 ipc_task_reset((imgp->ip_new_thread != NULL) ?
6096 get_threadtask(imgp->ip_new_thread) : p->task);
6097 ipc_thread_reset((imgp->ip_new_thread != NULL) ?
6098 imgp->ip_new_thread : current_thread());
6099 }
6100
6101 if (!leave_sugid_clear) {
6102 /*
6103 * Flag the process as setuid.
6104 */
6105 OSBitOrAtomic(P_SUGID, &p->p_flag);
6106
6107 /*
6108 * Radar 2261856; setuid security hole fix
6109 * XXX For setuid processes, attempt to ensure that
6110 * stdin, stdout, and stderr are already allocated.
6111 * We do not want userland to accidentally allocate
6112 * descriptors in this range which has implied meaning
6113 * to libc.
6114 */
6115 for (i = 0; i < 3; i++) {
6116 if (fp_get_noref_locked(p, i) != NULL) {
6117 continue;
6118 }
6119
6120 /*
6121 * Do the kernel equivalent of
6122 *
6123 * if i == 0
6124 * (void) open("/dev/null", O_RDONLY);
6125 * else
6126 * (void) open("/dev/null", O_WRONLY);
6127 */
6128
6129 struct fileproc *fp;
6130 int indx;
6131 int flag;
6132 struct nameidata *ndp = NULL;
6133
6134 if (i == 0) {
6135 flag = FREAD;
6136 } else {
6137 flag = FWRITE;
6138 }
6139
6140 if ((error = falloc(p,
6141 &fp, &indx, imgp->ip_vfs_context)) != 0) {
6142 continue;
6143 }
6144
6145 ndp = kalloc_type(struct nameidata,
6146 Z_WAITOK | Z_ZERO | Z_NOFAIL);
6147
6148 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
6149 CAST_USER_ADDR_T("/dev/null"),
6150 imgp->ip_vfs_context);
6151
6152 if ((error = vn_open(ndp, flag, 0)) != 0) {
6153 fp_free(p, indx, fp);
6154 kfree_type(struct nameidata, ndp);
6155 break;
6156 }
6157
6158 struct fileglob *fg = fp->fp_glob;
6159
6160 fg->fg_flag = flag;
6161 fg->fg_ops = &vnops;
6162 fp_set_data(fp, ndp->ni_vp);
6163
6164 vnode_put(ndp->ni_vp);
6165
6166 proc_fdlock(p);
6167 procfdtbl_releasefd(p, indx, NULL);
6168 fp_drop(p, indx, fp, 1);
6169 proc_fdunlock(p);
6170
6171 kfree_type(struct nameidata, ndp);
6172 }
6173 }
6174 }
6175 #if CONFIG_MACF
6176 else {
6177 /*
6178 * We are here because we were told that the MAC label will
6179 * be transitioned, and the binary is not VSUID or VSGID; to
6180 * deal with this case, we could either duplicate a lot of
6181 * code, or we can indicate we want to default the P_SUGID
6182 * bit clear and jump back up.
6183 */
6184 if (mac_transition) {
6185 leave_sugid_clear = 1;
6186 goto handle_mac_transition;
6187 }
6188 }
6189
6190 #endif /* CONFIG_MACF */
6191
6192 /*
6193 * Implement the semantic where the effective user and group become
6194 * the saved user and group in exec'ed programs.
6195 *
6196 * Modifications to p_ucred must be guarded using the
6197 * proc's ucred lock. This prevents others from accessing
6198 * a garbage credential.
6199 */
6200 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred) {
6201 return kauth_cred_setsvuidgid(my_cred,
6202 kauth_cred_getuid(my_cred),
6203 kauth_cred_getgid(my_cred));
6204 });
6205
6206 if (imgp->ip_new_thread != NULL) {
6207 task = get_threadtask(imgp->ip_new_thread);
6208 } else {
6209 task = p->task;
6210 }
6211
6212 /* Update the process' identity version and set the security token */
6213 proc_setpidversion(p, OSIncrementAtomic(&nextpidversion));
6214 task_set_uniqueid(task);
6215 set_security_token_task_internal(p, task);
6216
6217 return error;
6218 }
6219
6220
6221 /*
6222 * create_unix_stack
6223 *
6224 * Description: Set the user stack address for the process to the provided
6225 * address. If a custom stack was not set as a result of the
6226 * load process (i.e. as specified by the image file for the
6227 * executable), then allocate the stack in the provided map and
6228 * set up appropriate guard pages for enforcing administrative
6229 * limits on stack growth, if they end up being needed.
6230 *
6231 * Parameters: p Process to set stack on
6232 * load_result Information from mach-o load commands
6233 * map Address map in which to allocate the new stack
6234 *
6235 * Returns: KERN_SUCCESS Stack successfully created
6236 * !KERN_SUCCESS Mach failure code
6237 */
6238 __attribute__((noinline))
6239 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)6240 create_unix_stack(vm_map_t map, load_result_t* load_result,
6241 proc_t p)
6242 {
6243 mach_vm_size_t size, prot_size;
6244 mach_vm_offset_t addr, prot_addr;
6245 kern_return_t kr;
6246
6247 mach_vm_address_t user_stack = load_result->user_stack;
6248
6249 proc_lock(p);
6250 p->user_stack = (uintptr_t)user_stack;
6251 if (load_result->custom_stack) {
6252 p->p_lflag |= P_LCUSTOM_STACK;
6253 }
6254 proc_unlock(p);
6255 if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
6256 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);
6257 }
6258
6259 if (load_result->user_stack_alloc_size > 0) {
6260 /*
6261 * Allocate enough space for the maximum stack size we
6262 * will ever authorize and an extra page to act as
6263 * a guard page for stack overflows. For default stacks,
6264 * vm_initial_limit_stack takes care of the extra guard page.
6265 * Otherwise we must allocate it ourselves.
6266 */
6267 if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
6268 return KERN_INVALID_ARGUMENT;
6269 }
6270 addr = vm_map_trunc_page(load_result->user_stack - size,
6271 vm_map_page_mask(map));
6272 kr = mach_vm_allocate_kernel(map, &addr, size,
6273 VM_FLAGS_FIXED, VM_MEMORY_STACK);
6274 if (kr != KERN_SUCCESS) {
6275 // Can't allocate at default location, try anywhere
6276 addr = 0;
6277 kr = mach_vm_allocate_kernel(map, &addr, size,
6278 VM_FLAGS_ANYWHERE, VM_MEMORY_STACK);
6279 if (kr != KERN_SUCCESS) {
6280 return kr;
6281 }
6282
6283 user_stack = addr + size;
6284 load_result->user_stack = (user_addr_t)user_stack;
6285
6286 proc_lock(p);
6287 p->user_stack = (uintptr_t)user_stack;
6288 proc_unlock(p);
6289 }
6290
6291 load_result->user_stack_alloc = (user_addr_t)addr;
6292
6293 /*
6294 * And prevent access to what's above the current stack
6295 * size limit for this process.
6296 */
6297 if (load_result->user_stack_size == 0) {
6298 load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
6299 prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
6300 } else {
6301 prot_size = PAGE_SIZE;
6302 }
6303
6304 prot_addr = addr;
6305 kr = mach_vm_protect(map,
6306 prot_addr,
6307 prot_size,
6308 FALSE,
6309 VM_PROT_NONE);
6310 if (kr != KERN_SUCCESS) {
6311 (void)mach_vm_deallocate(map, addr, size);
6312 return kr;
6313 }
6314 }
6315
6316 return KERN_SUCCESS;
6317 }
6318
6319 #include <sys/reboot.h>
6320
6321 /*
6322 * load_init_program_at_path
6323 *
6324 * Description: Load the "init" program; in most cases, this will be "launchd"
6325 *
6326 * Parameters: p Process to call execve() to create
6327 * the "init" program
6328 * scratch_addr Page in p, scratch space
6329 * path NULL terminated path
6330 *
6331 * Returns: KERN_SUCCESS Success
6332 * !KERN_SUCCESS See execve/mac_execve for error codes
6333 *
6334 * Notes: The process that is passed in is the first manufactured
6335 * process on the system, and gets here via bsd_ast() firing
6336 * for the first time. This is done to ensure that bsd_init()
6337 * has run to completion.
6338 *
6339 * The address map of the first manufactured process matches the
6340 * word width of the kernel. Once the self-exec completes, the
6341 * initproc might be different.
6342 */
6343 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)6344 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
6345 {
6346 int retval[2];
6347 int error;
6348 struct execve_args init_exec_args;
6349 user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
6350
6351 /*
6352 * Validate inputs and pre-conditions
6353 */
6354 assert(p);
6355 assert(scratch_addr);
6356 assert(path);
6357
6358 /*
6359 * Copy out program name.
6360 */
6361 size_t path_length = strlen(path) + 1;
6362 argv0 = scratch_addr;
6363 error = copyout(path, argv0, path_length);
6364 if (error) {
6365 return error;
6366 }
6367
6368 scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
6369
6370 /*
6371 * Put out first (and only) argument, similarly.
6372 * Assumes everything fits in a page as allocated above.
6373 */
6374 if (boothowto & RB_SINGLE) {
6375 const char *init_args = "-s";
6376 size_t init_args_length = strlen(init_args) + 1;
6377
6378 argv1 = scratch_addr;
6379 error = copyout(init_args, argv1, init_args_length);
6380 if (error) {
6381 return error;
6382 }
6383
6384 scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
6385 }
6386
6387 if (proc_is64bit(p)) {
6388 user64_addr_t argv64bit[3] = {};
6389
6390 argv64bit[0] = argv0;
6391 argv64bit[1] = argv1;
6392 argv64bit[2] = USER_ADDR_NULL;
6393
6394 error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
6395 if (error) {
6396 return error;
6397 }
6398 } else {
6399 user32_addr_t argv32bit[3] = {};
6400
6401 argv32bit[0] = (user32_addr_t)argv0;
6402 argv32bit[1] = (user32_addr_t)argv1;
6403 argv32bit[2] = USER_ADDR_NULL;
6404
6405 error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
6406 if (error) {
6407 return error;
6408 }
6409 }
6410
6411 /*
6412 * Set up argument block for fake call to execve.
6413 */
6414 init_exec_args.fname = argv0;
6415 init_exec_args.argp = scratch_addr;
6416 init_exec_args.envp = USER_ADDR_NULL;
6417
6418 /*
6419 * So that init task is set with uid,gid 0 token
6420 */
6421 set_security_token(p);
6422
6423 return execve(p, &init_exec_args, retval);
6424 }
6425
6426 static const char * init_programs[] = {
6427 #if DEBUG
6428 "/usr/appleinternal/sbin/launchd.debug",
6429 #endif
6430 #if DEVELOPMENT || DEBUG
6431 "/usr/appleinternal/sbin/launchd.development",
6432 #endif
6433 "/sbin/launchd",
6434 };
6435
6436 /*
6437 * load_init_program
6438 *
6439 * Description: Load the "init" program; in most cases, this will be "launchd"
6440 *
6441 * Parameters: p Process to call execve() to create
6442 * the "init" program
6443 *
6444 * Returns: (void)
6445 *
6446 * Notes: The process that is passed in is the first manufactured
6447 * process on the system, and gets here via bsd_ast() firing
6448 * for the first time. This is done to ensure that bsd_init()
6449 * has run to completion.
6450 *
6451 * In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
6452 * may be used to select a specific launchd executable. As with
6453 * the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
6454 * will force /sbin/launchd to be selected.
6455 *
6456 * Search order by build:
6457 *
6458 * DEBUG DEVELOPMENT RELEASE PATH
6459 * ----------------------------------------------------------------------------------
6460 * 1 1 NA /usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
6461 * 2 NA NA /usr/appleinternal/sbin/launchd.debug
6462 * 3 2 NA /usr/appleinternal/sbin/launchd.development
6463 * 4 3 1 /sbin/launchd
6464 */
6465 void
load_init_program(proc_t p)6466 load_init_program(proc_t p)
6467 {
6468 uint32_t i;
6469 int error;
6470 vm_map_t map = current_map();
6471 mach_vm_offset_t scratch_addr = 0;
6472 mach_vm_size_t map_page_size = vm_map_page_size(map);
6473
6474 (void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size, VM_FLAGS_ANYWHERE, VM_KERN_MEMORY_NONE);
6475 #if CONFIG_MEMORYSTATUS
6476 (void) memorystatus_init_at_boot_snapshot();
6477 #endif /* CONFIG_MEMORYSTATUS */
6478
6479 #if DEBUG || DEVELOPMENT
6480 /* Check for boot-arg suffix first */
6481 char launchd_suffix[64];
6482 if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
6483 char launchd_path[128];
6484 boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
6485 (strcmp(launchd_suffix, "release") == 0));
6486
6487 if (is_release_suffix) {
6488 printf("load_init_program: attempting to load /sbin/launchd\n");
6489 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
6490 if (!error) {
6491 return;
6492 }
6493
6494 panic("Process 1 exec of launchd.release failed, errno %d", error);
6495 } else {
6496 strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
6497 strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
6498
6499 printf("load_init_program: attempting to load %s\n", launchd_path);
6500 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
6501 if (!error) {
6502 return;
6503 } else if (error != ENOENT) {
6504 printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
6505 }
6506 }
6507 }
6508 #endif
6509
6510 error = ENOENT;
6511 for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
6512 printf("load_init_program: attempting to load %s\n", init_programs[i]);
6513 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
6514 if (!error) {
6515 return;
6516 } else if (error != ENOENT) {
6517 printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
6518 }
6519 }
6520
6521 panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
6522 }
6523
6524 /*
6525 * load_return_to_errno
6526 *
6527 * Description: Convert a load_return_t (Mach error) to an errno (BSD error)
6528 *
6529 * Parameters: lrtn Mach error number
6530 *
6531 * Returns: (int) BSD error number
6532 * 0 Success
6533 * EBADARCH Bad architecture
6534 * EBADMACHO Bad Mach object file
6535 * ESHLIBVERS Bad shared library version
6536 * ENOMEM Out of memory/resource shortage
6537 * EACCES Access denied
6538 * ENOENT Entry not found (usually "file does
6539 * does not exist")
6540 * EIO An I/O error occurred
6541 * EBADEXEC The executable is corrupt/unknown
6542 */
6543 static int
load_return_to_errno(load_return_t lrtn)6544 load_return_to_errno(load_return_t lrtn)
6545 {
6546 switch (lrtn) {
6547 case LOAD_SUCCESS:
6548 return 0;
6549 case LOAD_BADARCH:
6550 return EBADARCH;
6551 case LOAD_BADMACHO:
6552 case LOAD_BADMACHO_UPX:
6553 return EBADMACHO;
6554 case LOAD_SHLIB:
6555 return ESHLIBVERS;
6556 case LOAD_NOSPACE:
6557 case LOAD_RESOURCE:
6558 return ENOMEM;
6559 case LOAD_PROTECT:
6560 return EACCES;
6561 case LOAD_ENOENT:
6562 return ENOENT;
6563 case LOAD_IOERROR:
6564 return EIO;
6565 case LOAD_DECRYPTFAIL:
6566 return EAUTH;
6567 case LOAD_FAILURE:
6568 default:
6569 return EBADEXEC;
6570 }
6571 }
6572
6573 #include <mach/mach_types.h>
6574 #include <mach/vm_prot.h>
6575 #include <mach/semaphore.h>
6576 #include <mach/sync_policy.h>
6577 #include <kern/clock.h>
6578 #include <mach/kern_return.h>
6579
6580 /*
6581 * execargs_alloc
6582 *
6583 * Description: Allocate the block of memory used by the execve arguments.
6584 * At the same time, we allocate a page so that we can read in
6585 * the first page of the image.
6586 *
6587 * Parameters: struct image_params * the image parameter block
6588 *
6589 * Returns: 0 Success
6590 * EINVAL Invalid argument
6591 * EACCES Permission denied
6592 * EINTR Interrupted function
6593 * ENOMEM Not enough space
6594 *
6595 * Notes: This is a temporary allocation into the kernel address space
6596 * to enable us to copy arguments in from user space. This is
6597 * necessitated by not mapping the process calling execve() into
6598 * the kernel address space during the execve() system call.
6599 *
6600 * We assemble the argument and environment, etc., into this
6601 * region before copying it as a single block into the child
6602 * process address space (at the top or bottom of the stack,
6603 * depending on which way the stack grows; see the function
6604 * exec_copyout_strings() for details).
6605 *
6606 * This ends up with a second (possibly unnecessary) copy compared
6607 * with assembing the data directly into the child address space,
6608 * instead, but since we cannot be guaranteed that the parent has
6609 * not modified its environment, we can't really know that it's
6610 * really a block there as well.
6611 */
6612
6613
6614 static int execargs_waiters = 0;
6615 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
6616
6617 static void
execargs_lock_lock(void)6618 execargs_lock_lock(void)
6619 {
6620 lck_mtx_lock_spin(&execargs_cache_lock);
6621 }
6622
6623 static void
execargs_lock_unlock(void)6624 execargs_lock_unlock(void)
6625 {
6626 lck_mtx_unlock(&execargs_cache_lock);
6627 }
6628
6629 static wait_result_t
execargs_lock_sleep(void)6630 execargs_lock_sleep(void)
6631 {
6632 return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
6633 }
6634
6635 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)6636 execargs_purgeable_allocate(char **execarg_address)
6637 {
6638 mach_vm_offset_t addr = 0;
6639 kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
6640 BSD_PAGEABLE_SIZE_PER_EXEC, VM_FLAGS_ANYWHERE | VM_FLAGS_PURGABLE,
6641 VM_KERN_MEMORY_NONE);
6642 *execarg_address = (char *)addr;
6643 assert(kr == KERN_SUCCESS);
6644 return kr;
6645 }
6646
6647 static kern_return_t
execargs_purgeable_reference(void * execarg_address)6648 execargs_purgeable_reference(void *execarg_address)
6649 {
6650 int state = VM_PURGABLE_NONVOLATILE;
6651 kern_return_t kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
6652
6653 assert(kr == KERN_SUCCESS);
6654 return kr;
6655 }
6656
6657 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)6658 execargs_purgeable_volatilize(void *execarg_address)
6659 {
6660 int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
6661 kern_return_t kr;
6662 kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
6663
6664 assert(kr == KERN_SUCCESS);
6665
6666 return kr;
6667 }
6668
6669 static void
execargs_wakeup_waiters(void)6670 execargs_wakeup_waiters(void)
6671 {
6672 thread_wakeup(&execargs_free_count);
6673 }
6674
6675 static int
execargs_alloc(struct image_params * imgp)6676 execargs_alloc(struct image_params *imgp)
6677 {
6678 kern_return_t kret;
6679 wait_result_t res;
6680 int i, cache_index = -1;
6681
6682 execargs_lock_lock();
6683
6684 while (execargs_free_count == 0) {
6685 execargs_waiters++;
6686 res = execargs_lock_sleep();
6687 execargs_waiters--;
6688 if (res != THREAD_AWAKENED) {
6689 execargs_lock_unlock();
6690 return EINTR;
6691 }
6692 }
6693
6694 execargs_free_count--;
6695
6696 for (i = 0; i < execargs_cache_size; i++) {
6697 vm_offset_t element = execargs_cache[i];
6698 if (element) {
6699 cache_index = i;
6700 imgp->ip_strings = (char *)(execargs_cache[i]);
6701 execargs_cache[i] = 0;
6702 break;
6703 }
6704 }
6705
6706 assert(execargs_free_count >= 0);
6707
6708 execargs_lock_unlock();
6709
6710 if (cache_index == -1) {
6711 kret = execargs_purgeable_allocate(&imgp->ip_strings);
6712 } else {
6713 kret = execargs_purgeable_reference(imgp->ip_strings);
6714 }
6715
6716 assert(kret == KERN_SUCCESS);
6717 if (kret != KERN_SUCCESS) {
6718 return ENOMEM;
6719 }
6720
6721 /* last page used to read in file headers */
6722 imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
6723 imgp->ip_strendp = imgp->ip_strings;
6724 imgp->ip_argspace = NCARGS;
6725 imgp->ip_strspace = (NCARGS + PAGE_SIZE);
6726
6727 return 0;
6728 }
6729
6730 /*
6731 * execargs_free
6732 *
6733 * Description: Free the block of memory used by the execve arguments and the
6734 * first page of the executable by a previous call to the function
6735 * execargs_alloc().
6736 *
6737 * Parameters: struct image_params * the image parameter block
6738 *
6739 * Returns: 0 Success
6740 * EINVAL Invalid argument
6741 * EINTR Oeration interrupted
6742 */
6743 static int
execargs_free(struct image_params * imgp)6744 execargs_free(struct image_params *imgp)
6745 {
6746 kern_return_t kret;
6747 int i;
6748 boolean_t needs_wakeup = FALSE;
6749
6750 kret = execargs_purgeable_volatilize(imgp->ip_strings);
6751
6752 execargs_lock_lock();
6753 execargs_free_count++;
6754
6755 for (i = 0; i < execargs_cache_size; i++) {
6756 vm_offset_t element = execargs_cache[i];
6757 if (element == 0) {
6758 execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
6759 imgp->ip_strings = NULL;
6760 break;
6761 }
6762 }
6763
6764 assert(imgp->ip_strings == NULL);
6765
6766 if (execargs_waiters > 0) {
6767 needs_wakeup = TRUE;
6768 }
6769
6770 execargs_lock_unlock();
6771
6772 if (needs_wakeup == TRUE) {
6773 execargs_wakeup_waiters();
6774 }
6775
6776 return kret == KERN_SUCCESS ? 0 : EINVAL;
6777 }
6778
6779 static void
exec_resettextvp(proc_t p,struct image_params * imgp)6780 exec_resettextvp(proc_t p, struct image_params *imgp)
6781 {
6782 vnode_t vp;
6783 off_t offset;
6784 vnode_t tvp = p->p_textvp;
6785 int ret;
6786
6787 vp = imgp->ip_vp;
6788 offset = imgp->ip_arch_offset;
6789
6790 if (vp == NULLVP) {
6791 panic("exec_resettextvp: expected valid vp");
6792 }
6793
6794 ret = vnode_ref(vp);
6795 proc_lock(p);
6796 if (ret == 0) {
6797 p->p_textvp = vp;
6798 p->p_textoff = offset;
6799 } else {
6800 p->p_textvp = NULLVP; /* this is paranoia */
6801 p->p_textoff = 0;
6802 }
6803 proc_unlock(p);
6804
6805 if (tvp != NULLVP) {
6806 if (vnode_getwithref(tvp) == 0) {
6807 vnode_rele(tvp);
6808 vnode_put(tvp);
6809 }
6810 }
6811 }
6812
6813 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
6814 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
6815
6816 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)6817 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
6818 {
6819 static char const nibble[] = "0123456789abcdef";
6820
6821 /* Apparently still the safest way to get a hex representation
6822 * of binary data.
6823 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
6824 * <rdar://problem/33328859> confusion around %*D/%nD in printf
6825 */
6826 for (int i = 0; i < CS_CDHASH_LEN; ++i) {
6827 str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
6828 str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
6829 }
6830 str[CS_CDHASH_STRING_SIZE - 1] = 0;
6831 }
6832
6833 /*
6834 * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
6835 *
6836 * Description: Waits for the userspace daemon to respond to the request
6837 * we made. Function declared non inline to be visible in
6838 * stackshots and spindumps as well as debugging.
6839 */
6840 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)6841 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
6842 {
6843 return find_code_signature(task_access_port, new_pid);
6844 }
6845
6846 static int
check_for_signature(proc_t p,struct image_params * imgp)6847 check_for_signature(proc_t p, struct image_params *imgp)
6848 {
6849 mach_port_t port = IPC_PORT_NULL;
6850 kern_return_t kr = KERN_FAILURE;
6851 int error = EACCES;
6852 boolean_t unexpected_failure = FALSE;
6853 struct cs_blob *csb;
6854 boolean_t require_success = FALSE;
6855 int spawn = (imgp->ip_flags & IMGPF_SPAWN);
6856 const int vfexec = 0;
6857 os_reason_t signature_failure_reason = OS_REASON_NULL;
6858
6859 /*
6860 * Override inherited code signing flags with the
6861 * ones for the process that is being successfully
6862 * loaded
6863 */
6864 proc_lock(p);
6865 proc_csflags_update(p, imgp->ip_csflags);
6866 proc_unlock(p);
6867
6868 /* Set the switch_protect flag on the map */
6869 if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
6870 vm_map_switch_protect(get_task_map(p->task), TRUE);
6871 }
6872 /* set the cs_enforced flags in the map */
6873 if (proc_getcsflags(p) & CS_ENFORCEMENT) {
6874 vm_map_cs_enforcement_set(get_task_map(p->task), TRUE);
6875 } else {
6876 vm_map_cs_enforcement_set(get_task_map(p->task), FALSE);
6877 }
6878
6879 /*
6880 * image activation may be failed due to policy
6881 * which is unexpected but security framework does not
6882 * approve of exec, kill and return immediately.
6883 */
6884 if (imgp->ip_mac_return != 0) {
6885 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
6886 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
6887 signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
6888 error = imgp->ip_mac_return;
6889 unexpected_failure = TRUE;
6890 goto done;
6891 }
6892
6893 if (imgp->ip_cs_error != OS_REASON_NULL) {
6894 signature_failure_reason = imgp->ip_cs_error;
6895 imgp->ip_cs_error = OS_REASON_NULL;
6896 error = EACCES;
6897 goto done;
6898 }
6899
6900 #if XNU_TARGET_OS_OSX
6901 /* Check for platform passed in spawn attr if iOS binary is being spawned */
6902 if (proc_platform(p) == PLATFORM_IOS) {
6903 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6904 if (psa == NULL || psa->psa_platform == 0) {
6905 boolean_t no_sandbox_entitled = FALSE;
6906 #if DEBUG || DEVELOPMENT
6907 /*
6908 * Allow iOS binaries to spawn on internal systems
6909 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
6910 * boot-arg set to true
6911 */
6912 if (unentitled_ios_sim_launch) {
6913 no_sandbox_entitled = TRUE;
6914 } else {
6915 no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
6916 (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
6917 }
6918 #endif /* DEBUG || DEVELOPMENT */
6919 if (!no_sandbox_entitled) {
6920 signature_failure_reason = os_reason_create(OS_REASON_EXEC,
6921 EXEC_EXIT_REASON_WRONG_PLATFORM);
6922 error = EACCES;
6923 goto done;
6924 }
6925 printf("Allowing spawn of iOS binary %s since it has "
6926 "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
6927 "boot-arg set to true\n", p->p_name);
6928 } else if (psa->psa_platform != PLATFORM_IOS) {
6929 /* Simulator binary spawned with wrong platform */
6930 signature_failure_reason = os_reason_create(OS_REASON_EXEC,
6931 EXEC_EXIT_REASON_WRONG_PLATFORM);
6932 error = EACCES;
6933 goto done;
6934 } else {
6935 printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
6936 p->p_name);
6937 }
6938 }
6939 #endif /* XNU_TARGET_OS_OSX */
6940
6941 /* If the code signature came through the image activation path, we skip the
6942 * taskgated / externally attached path. */
6943 if (imgp->ip_csflags & CS_SIGNED) {
6944 error = 0;
6945 goto done;
6946 }
6947
6948 /* The rest of the code is for signatures that either already have been externally
6949 * attached (likely, but not necessarily by a previous run through the taskgated
6950 * path), or that will now be attached by taskgated. */
6951
6952 kr = task_get_task_access_port(p->task, &port);
6953 if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
6954 error = 0;
6955 if (require_success) {
6956 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
6957 proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
6958 signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
6959 error = EACCES;
6960 }
6961 goto done;
6962 }
6963
6964 /*
6965 * taskgated returns KERN_SUCCESS if it has completed its work
6966 * and the exec should continue, KERN_FAILURE if the exec should
6967 * fail, or it may error out with different error code in an
6968 * event of mig failure (e.g. process was signalled during the
6969 * rpc call, taskgated died, mig server died etc.).
6970 */
6971
6972 kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
6973 switch (kr) {
6974 case KERN_SUCCESS:
6975 error = 0;
6976 break;
6977 case KERN_FAILURE:
6978 error = EACCES;
6979
6980 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
6981 proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
6982 signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
6983 goto done;
6984 default:
6985 error = EACCES;
6986
6987 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
6988 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
6989 signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
6990 unexpected_failure = TRUE;
6991 goto done;
6992 }
6993
6994 /* Only do this if exec_resettextvp() did not fail */
6995 if (p->p_textvp != NULLVP) {
6996 csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
6997
6998 if (csb != NULL) {
6999 /* As the enforcement we can do here is very limited, we only allow things that
7000 * are the only reason why this code path still exists:
7001 * Adhoc signed non-platform binaries without special cs_flags and without any
7002 * entitlements (unrestricted ones still pass AMFI). */
7003 if (
7004 /* Revalidate the blob if necessary through bumped generation count. */
7005 (ubc_cs_generation_check(p->p_textvp) == 0 ||
7006 ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
7007 /* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
7008 (csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
7009 /* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
7010 csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
7011 CSSLOT_SIGNATURESLOT,
7012 CSMAGIC_BLOBWRAPPER) == NULL &&
7013 /* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
7014 csb->csb_platform_binary == 0 &&
7015 /* No entitlements, not even unrestricted ones. */
7016 csb->csb_entitlements_blob == NULL &&
7017 csb->csb_der_entitlements_blob == NULL) {
7018 proc_lock(p);
7019 proc_csflags_set(p, CS_SIGNED | CS_VALID);
7020 proc_unlock(p);
7021 } else {
7022 uint8_t cdhash[CS_CDHASH_LEN];
7023 char cdhash_string[CS_CDHASH_STRING_SIZE];
7024 proc_getcdhash(p, cdhash);
7025 cdhash_to_string(cdhash_string, cdhash);
7026 printf("ignoring detached code signature on '%s' with cdhash '%s' "
7027 "because it is invalid, or not a simple adhoc signature.\n",
7028 p->p_name, cdhash_string);
7029 }
7030 }
7031 }
7032
7033 done:
7034 if (0 == error) {
7035 /* The process's code signature related properties are
7036 * fully set up, so this is an opportune moment to log
7037 * platform binary execution, if desired. */
7038 if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
7039 uint8_t cdhash[CS_CDHASH_LEN];
7040 char cdhash_string[CS_CDHASH_STRING_SIZE];
7041 proc_getcdhash(p, cdhash);
7042 cdhash_to_string(cdhash_string, cdhash);
7043
7044 os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
7045 "'%s' with cdhash %s\n", p->p_name, cdhash_string);
7046 }
7047 } else {
7048 if (!unexpected_failure) {
7049 proc_csflags_set(p, CS_KILLED);
7050 }
7051 /* make very sure execution fails */
7052 if (vfexec || spawn) {
7053 assert(signature_failure_reason != OS_REASON_NULL);
7054 psignal_vfork_with_reason(p, p->task, imgp->ip_new_thread,
7055 SIGKILL, signature_failure_reason);
7056 signature_failure_reason = OS_REASON_NULL;
7057 error = 0;
7058 } else {
7059 assert(signature_failure_reason != OS_REASON_NULL);
7060 psignal_with_reason(p, SIGKILL, signature_failure_reason);
7061 signature_failure_reason = OS_REASON_NULL;
7062 }
7063 }
7064
7065 if (port != IPC_PORT_NULL) {
7066 ipc_port_release_send(port);
7067 }
7068
7069 /* If we hit this, we likely would have leaked an exit reason */
7070 assert(signature_failure_reason == OS_REASON_NULL);
7071 return error;
7072 }
7073
7074 /*
7075 * Typically as soon as we start executing this process, the
7076 * first instruction will trigger a VM fault to bring the text
7077 * pages (as executable) into the address space, followed soon
7078 * thereafter by dyld data structures (for dynamic executable).
7079 * To optimize this, as well as improve support for hardware
7080 * debuggers that can only access resident pages present
7081 * in the process' page tables, we prefault some pages if
7082 * possible. Errors are non-fatal.
7083 */
7084 #ifndef PREVENT_CALLER_STACK_USE
7085 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
7086 #endif
7087 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(proc_t p __unused,struct image_params * imgp,load_result_t * load_result)7088 exec_prefault_data(proc_t p __unused, struct image_params *imgp, load_result_t *load_result)
7089 {
7090 int ret;
7091 size_t expected_all_image_infos_size;
7092 kern_return_t kr;
7093
7094 /*
7095 * Prefault executable or dyld entry point.
7096 */
7097 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7098 DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
7099 }
7100 kr = vm_fault(current_map(),
7101 vm_map_trunc_page(load_result->entry_point,
7102 vm_map_page_mask(current_map())),
7103 VM_PROT_READ | VM_PROT_EXECUTE,
7104 FALSE, VM_KERN_MEMORY_NONE,
7105 THREAD_UNINT, NULL, 0);
7106 if (kr != KERN_SUCCESS) {
7107 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);
7108 }
7109
7110 if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7111 expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
7112 } else {
7113 expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
7114 }
7115
7116 /* Decode dyld anchor structure from <mach-o/dyld_images.h> */
7117 if (load_result->dynlinker &&
7118 load_result->all_image_info_addr &&
7119 load_result->all_image_info_size >= expected_all_image_infos_size) {
7120 union {
7121 struct user64_dyld_all_image_infos infos64;
7122 struct user32_dyld_all_image_infos infos32;
7123 } all_image_infos;
7124
7125 /*
7126 * Pre-fault to avoid copyin() going through the trap handler
7127 * and recovery path.
7128 */
7129 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7130 DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
7131 }
7132 kr = vm_fault(current_map(),
7133 vm_map_trunc_page(load_result->all_image_info_addr,
7134 vm_map_page_mask(current_map())),
7135 VM_PROT_READ | VM_PROT_WRITE,
7136 FALSE, VM_KERN_MEMORY_NONE,
7137 THREAD_UNINT, NULL, 0);
7138 if (kr != KERN_SUCCESS) {
7139 // 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);
7140 }
7141 if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
7142 /* all_image_infos straddles a page */
7143 kr = vm_fault(current_map(),
7144 vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
7145 vm_map_page_mask(current_map())),
7146 VM_PROT_READ | VM_PROT_WRITE,
7147 FALSE, VM_KERN_MEMORY_NONE,
7148 THREAD_UNINT, NULL, 0);
7149 if (kr != KERN_SUCCESS) {
7150 // 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);
7151 }
7152 }
7153
7154 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7155 DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
7156 }
7157 ret = copyin((user_addr_t)load_result->all_image_info_addr,
7158 &all_image_infos,
7159 expected_all_image_infos_size);
7160 if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
7161 user_addr_t notification_address;
7162 user_addr_t dyld_image_address;
7163 user_addr_t dyld_version_address;
7164 user_addr_t dyld_all_image_infos_address;
7165 user_addr_t dyld_slide_amount;
7166
7167 if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7168 notification_address = (user_addr_t)all_image_infos.infos64.notification;
7169 dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
7170 dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
7171 dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
7172 } else {
7173 notification_address = all_image_infos.infos32.notification;
7174 dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
7175 dyld_version_address = all_image_infos.infos32.dyldVersion;
7176 dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
7177 }
7178
7179 /*
7180 * dyld statically sets up the all_image_infos in its Mach-O
7181 * binary at static link time, with pointers relative to its default
7182 * load address. Since ASLR might slide dyld before its first
7183 * instruction is executed, "dyld_slide_amount" tells us how far
7184 * dyld was loaded compared to its default expected load address.
7185 * All other pointers into dyld's image should be adjusted by this
7186 * amount. At some point later, dyld will fix up pointers to take
7187 * into account the slide, at which point the all_image_infos_address
7188 * field in the structure will match the runtime load address, and
7189 * "dyld_slide_amount" will be 0, if we were to consult it again.
7190 */
7191
7192 dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
7193
7194 #if 0
7195 kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
7196 (uint64_t)load_result->all_image_info_addr,
7197 all_image_infos.infos32.version,
7198 (uint64_t)notification_address,
7199 (uint64_t)dyld_image_address,
7200 (uint64_t)dyld_version_address,
7201 (uint64_t)dyld_all_image_infos_address);
7202 #endif
7203
7204 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7205 DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
7206 }
7207 kr = vm_fault(current_map(),
7208 vm_map_trunc_page(notification_address + dyld_slide_amount,
7209 vm_map_page_mask(current_map())),
7210 VM_PROT_READ | VM_PROT_EXECUTE,
7211 FALSE, VM_KERN_MEMORY_NONE,
7212 THREAD_UNINT, NULL, 0);
7213 if (kr != KERN_SUCCESS) {
7214 // 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);
7215 }
7216 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7217 DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
7218 }
7219 kr = vm_fault(current_map(),
7220 vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
7221 vm_map_page_mask(current_map())),
7222 VM_PROT_READ | VM_PROT_EXECUTE,
7223 FALSE, VM_KERN_MEMORY_NONE,
7224 THREAD_UNINT, NULL, 0);
7225 if (kr != KERN_SUCCESS) {
7226 // 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);
7227 }
7228 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7229 DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
7230 }
7231 kr = vm_fault(current_map(),
7232 vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
7233 vm_map_page_mask(current_map())),
7234 VM_PROT_READ,
7235 FALSE, VM_KERN_MEMORY_NONE,
7236 THREAD_UNINT, NULL, 0);
7237 if (kr != KERN_SUCCESS) {
7238 // 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);
7239 }
7240 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7241 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);
7242 }
7243 kr = vm_fault(current_map(),
7244 vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
7245 vm_map_page_mask(current_map())),
7246 VM_PROT_READ | VM_PROT_WRITE,
7247 FALSE, VM_KERN_MEMORY_NONE,
7248 THREAD_UNINT, NULL, 0);
7249 if (kr != KERN_SUCCESS) {
7250 // 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);
7251 }
7252 }
7253 }
7254 }
7255
7256 static int
7257 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
7258 {
7259 #pragma unused(oidp, arg2, req)
7260 int changed;
7261 errno_t error;
7262 uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
7263
7264 error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
7265 if (error) {
7266 return error;
7267 }
7268
7269 if (changed) {
7270 os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
7271 }
7272
7273 return 0;
7274 }
7275
7276 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
7277
7278