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 if (lret != LOAD_SUCCESS) {
764 error = load_return_to_errno(lret);
765 goto bad;
766 }
767
768 /* If posix_spawn binprefs exist, respect those prefs. */
769 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
770 if (psa != NULL && psa->psa_binprefs[0] != 0) {
771 uint32_t pr = 0;
772
773 /* Check each preference listed against all arches in header */
774 for (pr = 0; pr < NBINPREFS; pr++) {
775 cpu_type_t pref = psa->psa_binprefs[pr];
776 cpu_type_t subpref = psa->psa_subcpuprefs[pr];
777
778 if (pref == 0) {
779 /* No suitable arch in the pref list */
780 error = EBADARCH;
781 goto bad;
782 }
783
784 if (pref == CPU_TYPE_ANY) {
785 /* Fall through to regular grading */
786 goto regular_grading;
787 }
788
789 lret = fatfile_getbestarch_for_cputype(pref,
790 subpref,
791 (vm_offset_t)fat_header,
792 PAGE_SIZE,
793 imgp,
794 &fat_arch);
795 if (lret == LOAD_SUCCESS) {
796 goto use_arch;
797 }
798 }
799
800 /* Requested binary preference was not honored */
801 error = EBADEXEC;
802 goto bad;
803 }
804
805 regular_grading:
806 /* Look up our preferred architecture in the fat file. */
807 lret = fatfile_getbestarch((vm_offset_t)fat_header,
808 PAGE_SIZE,
809 imgp,
810 &fat_arch,
811 (p->p_flag & P_AFFINITY) != 0);
812 if (lret != LOAD_SUCCESS) {
813 error = load_return_to_errno(lret);
814 goto bad;
815 }
816
817 use_arch:
818 /* Read the Mach-O header out of fat_arch */
819 error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
820 PAGE_SIZE, fat_arch.offset,
821 UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
822 cred, &resid, p);
823 if (error) {
824 goto bad;
825 }
826
827 if (resid) {
828 memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
829 }
830
831 /* Success. Indicate we have identified an encapsulated binary */
832 error = -2;
833 imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
834 imgp->ip_arch_size = (user_size_t)fat_arch.size;
835 imgp->ip_origcputype = fat_arch.cputype;
836 imgp->ip_origcpusubtype = fat_arch.cpusubtype;
837
838 bad:
839 kauth_cred_unref(&cred);
840 return error;
841 }
842
843 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)844 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
845 {
846 int ret;
847
848 task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0);
849 task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
850 if (result->is_64bit_addr) {
851 OSBitOrAtomic(P_LP64, &p->p_flag);
852 get_bsdthread_info(thread)->uu_flag |= UT_LP64;
853 } else {
854 OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
855 get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
856 }
857 task_set_mach_header_address(task, result->mach_header);
858
859 ret = thread_state_initialize(thread);
860 if (ret != KERN_SUCCESS) {
861 return ret;
862 }
863
864 if (result->threadstate) {
865 uint32_t *ts = result->threadstate;
866 uint32_t total_size = (uint32_t)result->threadstate_sz;
867
868 while (total_size > 0) {
869 uint32_t flavor = *ts++;
870 uint32_t size = *ts++;
871
872 ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
873 if (ret) {
874 return ret;
875 }
876 ts += size;
877 total_size -= (size + 2) * sizeof(uint32_t);
878 }
879 }
880
881 thread_setentrypoint(thread, result->entry_point);
882
883 return KERN_SUCCESS;
884 }
885
886
887 void
set_proc_name(struct image_params * imgp,proc_t p)888 set_proc_name(struct image_params *imgp, proc_t p)
889 {
890 int p_name_len = sizeof(p->p_name) - 1;
891
892 if (imgp->ip_ndp->ni_cnd.cn_namelen > p_name_len) {
893 imgp->ip_ndp->ni_cnd.cn_namelen = p_name_len;
894 }
895
896 bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name,
897 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
898 p->p_name[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
899
900 if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN) {
901 imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
902 }
903
904 bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
905 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
906 p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
907 }
908
909 #if __has_feature(ptrauth_calls)
910 /**
911 * Returns a team ID string that may be used to assign a shared region.
912 *
913 * Platform binaries do not have team IDs and will return NULL. Non-platform
914 * binaries without a team ID will be assigned an artificial team ID of ""
915 * (empty string) so that they will not be assigned to the default shared
916 * region.
917 *
918 * @param imgp image parameter block
919 * @return NULL if this is a platform binary, or an appropriate team ID string
920 * otherwise
921 */
922 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)923 get_teamid_for_shared_region(struct image_params *imgp)
924 {
925 assert(imgp->ip_vp != NULL);
926
927 const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
928 if (ret) {
929 return ret;
930 }
931
932 struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
933 if (csblob_get_platform_binary(blob)) {
934 return NULL;
935 } else {
936 static const char *NO_TEAM_ID = "";
937 return NO_TEAM_ID;
938 }
939 }
940
941 /**
942 * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
943 *
944 * @param cpusubtype Mach-O style CPU subtype
945 * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
946 */
947 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)948 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
949 {
950 return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
951 CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
952 }
953
954 #endif /* __has_feature(ptrauth_calls) */
955
956 /**
957 * Returns whether a type/subtype slice matches the requested
958 * type/subtype.
959 *
960 * @param mask Bits to mask from the requested/tested cpu type
961 * @param req_cpu Requested cpu type
962 * @param req_subcpu Requested cpu subtype
963 * @param test_cpu Tested slice cpu type
964 * @param test_subcpu Tested slice cpu subtype
965 */
966 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)967 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
968 cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
969 cpu_subtype_t test_subcpu)
970 {
971 if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
972 return FALSE;
973 }
974
975 test_subcpu &= ~CPU_SUBTYPE_MASK;
976 req_subcpu &= ~CPU_SUBTYPE_MASK;
977
978 if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
979 return FALSE;
980 }
981
982 return TRUE;
983 }
984
985
986 /*
987 * exec_mach_imgact
988 *
989 * Image activator for mach-o 1.0 binaries.
990 *
991 * Parameters; struct image_params * image parameter block
992 *
993 * Returns: -1 not a fat binary (keep looking)
994 * -2 Success: encapsulated binary: reread
995 * >0 Failure: error number
996 * EBADARCH Mach-o binary, but with an unrecognized
997 * architecture
998 * ENOMEM No memory for child process after -
999 * can only happen after vfork()
1000 *
1001 * Important: This image activator is NOT byte order neutral.
1002 *
1003 * Note: A return value other than -1 indicates subsequent image
1004 * activators should not be given the opportunity to attempt
1005 * to activate the image.
1006 */
1007 static int
exec_mach_imgact(struct image_params * imgp)1008 exec_mach_imgact(struct image_params *imgp)
1009 {
1010 struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1011 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
1012 int error = 0;
1013 task_t task;
1014 task_t new_task = NULL; /* protected by vfexec */
1015 thread_t thread;
1016 struct uthread *uthread;
1017 vm_map_t old_map = VM_MAP_NULL;
1018 vm_map_t map = VM_MAP_NULL;
1019 load_return_t lret;
1020 load_result_t load_result = {};
1021 struct _posix_spawnattr *psa = NULL;
1022 int spawn = (imgp->ip_flags & IMGPF_SPAWN);
1023 const int vfexec = 0;
1024 int exec = (imgp->ip_flags & IMGPF_EXEC);
1025 os_reason_t exec_failure_reason = OS_REASON_NULL;
1026 boolean_t reslide = FALSE;
1027
1028 /*
1029 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1030 * is a reserved field on the end, so for the most part, we can
1031 * treat them as if they were identical. Reverse-endian Mach-O
1032 * binaries are recognized but not compatible.
1033 */
1034 if ((mach_header->magic == MH_CIGAM) ||
1035 (mach_header->magic == MH_CIGAM_64)) {
1036 error = EBADARCH;
1037 goto bad;
1038 }
1039
1040 if ((mach_header->magic != MH_MAGIC) &&
1041 (mach_header->magic != MH_MAGIC_64)) {
1042 error = -1;
1043 goto bad;
1044 }
1045
1046 if (mach_header->filetype != MH_EXECUTE) {
1047 error = -1;
1048 goto bad;
1049 }
1050
1051 if (imgp->ip_origcputype != 0) {
1052 /* Fat header previously had an idea about this thin file */
1053 if (imgp->ip_origcputype != mach_header->cputype ||
1054 imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1055 error = EBADARCH;
1056 goto bad;
1057 }
1058 } else {
1059 imgp->ip_origcputype = mach_header->cputype;
1060 imgp->ip_origcpusubtype = mach_header->cpusubtype;
1061 }
1062
1063 task = current_task();
1064 thread = current_thread();
1065 uthread = get_bsdthread_info(thread);
1066
1067 if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1068 imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1069 }
1070
1071
1072 /* If posix_spawn binprefs exist, respect those prefs. */
1073 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1074 if (psa != NULL && psa->psa_binprefs[0] != 0) {
1075 int pr = 0;
1076 for (pr = 0; pr < NBINPREFS; pr++) {
1077 cpu_type_t pref = psa->psa_binprefs[pr];
1078 cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1079
1080 if (pref == 0) {
1081 /* No suitable arch in the pref list */
1082 error = EBADARCH;
1083 goto bad;
1084 }
1085
1086 if (pref == CPU_TYPE_ANY) {
1087 /* Jump to regular grading */
1088 goto grade;
1089 }
1090
1091 if (binary_match(CPU_ARCH_MASK, pref, subpref,
1092 imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1093 goto grade;
1094 }
1095 }
1096 error = EBADARCH;
1097 goto bad;
1098 }
1099 grade:
1100 if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1101 imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1102 error = EBADARCH;
1103 goto bad;
1104 }
1105
1106 if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1107 imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1108 #if __x86_64__
1109 const char *excpath;
1110 error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1111 os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1112 #endif
1113 error = EBADARCH;
1114 goto bad;
1115 }
1116
1117 #if defined(HAS_APPLE_PAC)
1118 assert(mach_header->cputype == CPU_TYPE_ARM64
1119 );
1120
1121 if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1122 arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1123 ) {
1124 imgp->ip_flags &= ~IMGPF_NOJOP;
1125 } else {
1126 imgp->ip_flags |= IMGPF_NOJOP;
1127 }
1128 #endif
1129
1130 /* Copy in arguments/environment from the old process */
1131 error = exec_extract_strings(imgp);
1132 if (error) {
1133 goto bad;
1134 }
1135
1136 AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1137 imgp->ip_endargv - imgp->ip_startargv);
1138 AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1139 imgp->ip_endenvv - imgp->ip_endargv);
1140
1141
1142
1143 /* reset local idea of thread, uthread, task */
1144 thread = imgp->ip_new_thread;
1145 uthread = get_bsdthread_info(thread);
1146 task = new_task = get_threadtask(thread);
1147
1148 /*
1149 * Load the Mach-O file.
1150 *
1151 * NOTE: An error after this point indicates we have potentially
1152 * destroyed or overwritten some process state while attempting an
1153 * execve() following a vfork(), which is an unrecoverable condition.
1154 * We send the new process an immediate SIGKILL to avoid it executing
1155 * any instructions in the mutated address space. For true spawns,
1156 * this is not the case, and "too late" is still not too late to
1157 * return an error code to the parent process.
1158 */
1159
1160 /*
1161 * Actually load the image file we previously decided to load.
1162 */
1163 lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1164 if (lret != LOAD_SUCCESS) {
1165 error = load_return_to_errno(lret);
1166
1167 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1168 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1169 if (lret == LOAD_BADMACHO_UPX) {
1170 set_proc_name(imgp, p);
1171 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1172 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1173 } else {
1174 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1175
1176 if (bootarg_execfailurereports) {
1177 set_proc_name(imgp, p);
1178 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1179 }
1180 }
1181
1182 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1183
1184 goto badtoolate;
1185 }
1186
1187 #ifndef KASAN
1188 /*
1189 * Security: zone sanity checks on fresh boot or initproc re-exec.
1190 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1191 * which means here is the earliest point we can assert on empty service port label zone,
1192 * after load_machfile() above terminates old launchd's IPC space.
1193 *
1194 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1195 * under quarantine.
1196 */
1197 if (task_pid(task) == 1) {
1198 assert(get_bsdtask_info(task) == initproc);
1199 zone_userspace_reboot_checks();
1200 }
1201 #endif
1202
1203 proc_lock(p);
1204 {
1205 p->p_cputype = imgp->ip_origcputype;
1206 p->p_cpusubtype = imgp->ip_origcpusubtype;
1207 }
1208 proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1209 vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1210 vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1211 vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1212 #if XNU_TARGET_OS_OSX
1213 if (proc_platform(p) == PLATFORM_IOS) {
1214 assert(vm_map_is_alien(map));
1215 } else {
1216 assert(!vm_map_is_alien(map));
1217 }
1218 #endif /* XNU_TARGET_OS_OSX */
1219 proc_unlock(p);
1220
1221 /*
1222 * Set code-signing flags if this binary is signed, or if parent has
1223 * requested them on exec.
1224 */
1225 if (load_result.csflags & CS_VALID) {
1226 imgp->ip_csflags |= load_result.csflags &
1227 (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1228 CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1229 CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1230 CS_ENTITLEMENT_FLAGS |
1231 CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1232 } else {
1233 imgp->ip_csflags &= ~CS_VALID;
1234 }
1235
1236 if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1237 imgp->ip_csflags |= CS_HARD;
1238 }
1239 if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1240 imgp->ip_csflags |= CS_KILL;
1241 }
1242 if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1243 imgp->ip_csflags |= CS_ENFORCEMENT;
1244 }
1245 if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1246 if (proc_getcsflags(p) & CS_INSTALLER) {
1247 imgp->ip_csflags |= CS_INSTALLER;
1248 }
1249 if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1250 imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1251 }
1252 if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1253 imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1254 }
1255 }
1256
1257 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1258 /*
1259 * ptrauth version 0 is a preview ABI. Developers can opt into running
1260 * their own arm64e binaries for local testing, with the understanding
1261 * that future OSes may break ABI.
1262 */
1263 if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1264 CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1265 !load_result.platform_binary &&
1266 !bootarg_arm64e_preview_abi) {
1267 static bool logged_once = false;
1268 set_proc_name(imgp, p);
1269
1270 printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1271 if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1272 printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1273 }
1274
1275 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1276 if (bootarg_execfailurereports) {
1277 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1278 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1279 }
1280 goto badtoolate;
1281 }
1282
1283 if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1284 imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1285 load_result.platform_binary &&
1286 (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1287 set_proc_name(imgp, p);
1288 printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
1289 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1290 if (bootarg_execfailurereports) {
1291 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1292 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1293 }
1294 goto badtoolate;
1295 }
1296 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1297
1298
1299 /*
1300 * Set up the shared cache region in the new process.
1301 *
1302 * Normally there is a single shared region per architecture.
1303 * However on systems with Pointer Authentication, we can create
1304 * multiple shared caches with the amount of sharing determined
1305 * by team-id or entitlement. Inherited shared region IDs are used
1306 * for system processes that need to match and be able to inspect
1307 * a pre-existing task.
1308 */
1309 int cpu_subtype = 0; /* all cpu_subtypes use the same shared region */
1310 #if __has_feature(ptrauth_calls)
1311 char *shared_region_id = NULL;
1312 size_t len;
1313 char *base;
1314 const char *cbase;
1315 #define TEAM_ID_PREFIX "T-"
1316 #define ENTITLE_PREFIX "E-"
1317 #define SR_PREFIX_LEN 2
1318 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1319
1320 if (cpu_type() == CPU_TYPE_ARM64 &&
1321 arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1322 (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1323 assertf(p->p_cputype == CPU_TYPE_ARM64,
1324 "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1325 p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1326
1327 /*
1328 * arm64e uses pointer authentication, so request a separate
1329 * shared region for this CPU subtype.
1330 */
1331 cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1332
1333 /*
1334 * Determine which shared cache to select based on being told,
1335 * matching a team-id or matching an entitlement.
1336 */
1337 if (imgp->ip_inherited_shared_region_id) {
1338 len = strlen(imgp->ip_inherited_shared_region_id);
1339 shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1340 memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1341 } else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1342 len = strlen(cbase);
1343 if (vm_shared_region_per_team_id) {
1344 shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1345 Z_WAITOK | Z_NOFAIL);
1346 memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1347 memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1348 }
1349 } else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1350 (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1351 len = strlen(base);
1352 if (vm_shared_region_by_entitlement) {
1353 shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1354 Z_WAITOK | Z_NOFAIL);
1355 memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1356 memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1357 }
1358 /* Discard the copy of the entitlement */
1359 kfree_data(base, len + 1);
1360 }
1361 }
1362
1363 if (imgp->ip_flags & IMGPF_RESLIDE) {
1364 reslide = TRUE;
1365 }
1366
1367 /* use "" as the default shared_region_id */
1368 if (shared_region_id == NULL) {
1369 shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1370 }
1371
1372 /* ensure there's a unique pointer signing key for this shared_region_id */
1373 shared_region_key_alloc(shared_region_id,
1374 imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1375 task_set_shared_region_id(task, shared_region_id);
1376 shared_region_id = NULL;
1377 #endif /* __has_feature(ptrauth_calls) */
1378
1379 int cputype = cpu_type();
1380 vm_map_exec(map, task, load_result.is_64bit_addr,
1381 (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide, (imgp->ip_flags & IMGPF_DRIVER) != 0 && vm_enable_driverkit_shared_region);
1382
1383 /*
1384 * Close file descriptors which specify close-on-exec.
1385 */
1386 fdt_exec(p, psa != NULL ? psa->psa_flags : 0);
1387
1388 /*
1389 * deal with set[ug]id.
1390 */
1391 error = exec_handle_sugid(imgp);
1392 if (error) {
1393 vm_map_deallocate(map);
1394
1395 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1396 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1397
1398 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1399 if (bootarg_execfailurereports) {
1400 set_proc_name(imgp, p);
1401 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1402 }
1403
1404 goto badtoolate;
1405 }
1406
1407 /*
1408 * Commit to new map.
1409 *
1410 * Swap the new map for the old for target task, which consumes
1411 * our new map reference but each leaves us responsible for the
1412 * old_map reference. That lets us get off the pmap associated
1413 * with it, and then we can release it.
1414 *
1415 * The map needs to be set on the target task which is different
1416 * than current task, thus swap_task_map is used instead of
1417 * vm_map_switch.
1418 */
1419 old_map = swap_task_map(task, thread, map);
1420 vm_map_deallocate(old_map);
1421 old_map = NULL;
1422
1423 lret = activate_exec_state(task, p, thread, &load_result);
1424 if (lret != KERN_SUCCESS) {
1425 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1426 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1427
1428 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1429 if (bootarg_execfailurereports) {
1430 set_proc_name(imgp, p);
1431 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1432 }
1433
1434 goto badtoolate;
1435 }
1436
1437 /*
1438 * deal with voucher on exec-calling thread.
1439 */
1440 if (imgp->ip_new_thread == NULL) {
1441 thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1442 }
1443
1444 /* Make sure we won't interrupt ourself signalling a partial process */
1445 if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1446 psignal(p, SIGTRAP);
1447 }
1448
1449 if (load_result.unixproc &&
1450 create_unix_stack(get_task_map(task),
1451 &load_result,
1452 p) != KERN_SUCCESS) {
1453 error = load_return_to_errno(LOAD_NOSPACE);
1454
1455 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1456 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1457
1458 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1459 if (bootarg_execfailurereports) {
1460 set_proc_name(imgp, p);
1461 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1462 }
1463
1464 goto badtoolate;
1465 }
1466
1467 /*
1468 * The load result will have already been munged by AMFI to include the
1469 * platform binary flag if boot-args dictated it (AMFI will mark anything
1470 * that doesn't go through the upcall path as a platform binary if its
1471 * enforcement is disabled).
1472 */
1473 if (load_result.platform_binary) {
1474 if (cs_debug) {
1475 printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1476 }
1477
1478 /*
1479 * We must use 'task' here because the proc's task has not yet been
1480 * switched to the new one.
1481 */
1482 task_set_platform_binary(task, TRUE);
1483 } else {
1484 if (cs_debug) {
1485 printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1486 }
1487
1488 task_set_platform_binary(task, FALSE);
1489 }
1490
1491 /*
1492 * Set starting EXC_GUARD and control port behavior for task now that
1493 * platform is set. Use the name directly from imgp since we haven't
1494 * set_proc_name() yet. Also make control port for the task and main thread
1495 * immovable/pinned based on task's option.
1496 *
1497 * Must happen before main thread port copyout in exc_add_apple_strings.
1498 */
1499 task_set_exc_guard_ctrl_port_default(task, thread,
1500 imgp->ip_ndp->ni_cnd.cn_nameptr,
1501 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1502 proc_is_simulated(p),
1503 load_result.ip_platform,
1504 load_result.lr_sdk);
1505
1506 error = exec_add_apple_strings(imgp, &load_result); /* copies out main thread port */
1507
1508 if (error) {
1509 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1510 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
1511
1512 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
1513 if (bootarg_execfailurereports) {
1514 set_proc_name(imgp, p);
1515 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1516 }
1517 goto badtoolate;
1518 }
1519
1520 /* Switch to target task's map to copy out strings */
1521 old_map = vm_map_switch(get_task_map(task));
1522
1523 if (load_result.unixproc) {
1524 user_addr_t ap;
1525
1526 /*
1527 * Copy the strings area out into the new process address
1528 * space.
1529 */
1530 ap = p->user_stack;
1531 error = exec_copyout_strings(imgp, &ap);
1532 if (error) {
1533 vm_map_switch(old_map);
1534
1535 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1536 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
1537
1538 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
1539 if (bootarg_execfailurereports) {
1540 set_proc_name(imgp, p);
1541 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1542 }
1543 goto badtoolate;
1544 }
1545 /* Set the stack */
1546 thread_setuserstack(thread, ap);
1547 }
1548
1549 if (load_result.dynlinker || load_result.is_cambria) {
1550 user_addr_t ap;
1551 int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
1552
1553 /* Adjust the stack */
1554 ap = thread_adjuserstack(thread, -new_ptr_size);
1555 error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
1556
1557 if (error) {
1558 vm_map_switch(old_map);
1559
1560 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1561 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
1562
1563 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
1564 if (bootarg_execfailurereports) {
1565 set_proc_name(imgp, p);
1566 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1567 }
1568 goto badtoolate;
1569 }
1570 task_set_dyld_info(task, load_result.all_image_info_addr,
1571 load_result.all_image_info_size);
1572 }
1573
1574
1575 /* Avoid immediate VM faults back into kernel */
1576 exec_prefault_data(p, imgp, &load_result);
1577
1578 vm_map_switch(old_map);
1579
1580 /*
1581 * Reset signal state.
1582 */
1583 execsigs(p, thread);
1584
1585 /*
1586 * need to cancel async IO requests that can be cancelled and wait for those
1587 * already active. MAY BLOCK!
1588 */
1589 _aio_exec( p );
1590
1591 #if SYSV_SHM
1592 /* FIXME: Till vmspace inherit is fixed: */
1593 if (!vfexec && p->vm_shm) {
1594 shmexec(p);
1595 }
1596 #endif
1597 #if SYSV_SEM
1598 /* Clean up the semaphores */
1599 semexit(p);
1600 #endif
1601
1602 /*
1603 * Remember file name for accounting.
1604 */
1605 p->p_acflag &= ~AFORK;
1606
1607 set_proc_name(imgp, p);
1608
1609 #if CONFIG_SECLUDED_MEMORY
1610 if (secluded_for_apps &&
1611 load_result.platform_binary) {
1612 if (strncmp(p->p_name,
1613 "Camera",
1614 sizeof(p->p_name)) == 0) {
1615 task_set_could_use_secluded_mem(task, TRUE);
1616 } else {
1617 task_set_could_use_secluded_mem(task, FALSE);
1618 }
1619 if (strncmp(p->p_name,
1620 "mediaserverd",
1621 sizeof(p->p_name)) == 0) {
1622 task_set_could_also_use_secluded_mem(task, TRUE);
1623 }
1624 }
1625 #endif /* CONFIG_SECLUDED_MEMORY */
1626
1627 #if __arm64__
1628 if (load_result.legacy_footprint) {
1629 task_set_legacy_footprint(task);
1630 }
1631 #endif /* __arm64__ */
1632
1633 pal_dbg_set_task_name(task);
1634
1635 #if DEVELOPMENT || DEBUG
1636 /*
1637 * Update the pid an proc name for importance base if any
1638 */
1639 task_importance_update_owner_info(task);
1640 #endif
1641
1642 proc_setexecutableuuid(p, &load_result.uuid[0]);
1643
1644 #if CONFIG_DTRACE
1645 dtrace_proc_exec(p);
1646 #endif
1647
1648 if (kdebug_enable) {
1649 long args[4] = {};
1650
1651 uintptr_t fsid = 0, fileid = 0;
1652 if (imgp->ip_vattr) {
1653 uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
1654 fsid = (uintptr_t)fsid64;
1655 fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
1656 // check for (unexpected) overflow and trace zero in that case
1657 if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
1658 fsid = fileid = 0;
1659 }
1660 }
1661 KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
1662 (uintptr_t)thread_tid(thread));
1663
1664 /*
1665 * Collect the pathname for tracing
1666 */
1667 kdbg_trace_string(p, &args[0], &args[1], &args[2], &args[3]);
1668 KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
1669 args[2], args[3], (uintptr_t)thread_tid(thread));
1670 }
1671
1672
1673 /*
1674 * If posix_spawned with the START_SUSPENDED flag, stop the
1675 * process before it runs.
1676 */
1677 if (imgp->ip_px_sa != NULL) {
1678 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1679 if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
1680 proc_lock(p);
1681 p->p_stat = SSTOP;
1682 proc_unlock(p);
1683 (void) task_suspend_internal(task);
1684 }
1685 }
1686
1687 /*
1688 * mark as execed
1689 */
1690 OSBitOrAtomic(P_EXEC, &p->p_flag);
1691 proc_resetregister(p);
1692 if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
1693 proc_lock(p);
1694 p->p_lflag &= ~P_LPPWAIT;
1695 proc_unlock(p);
1696 wakeup((caddr_t)p->p_pptr);
1697 }
1698
1699
1700 goto done;
1701
1702 badtoolate:
1703 /* Don't allow child process to execute any instructions */
1704 if (!spawn) {
1705 {
1706 assert(exec_failure_reason != OS_REASON_NULL);
1707 psignal_with_reason(p, SIGKILL, exec_failure_reason);
1708 exec_failure_reason = OS_REASON_NULL;
1709
1710 if (exec) {
1711 /* Terminate the exec copy task */
1712 task_terminate_internal(task);
1713 }
1714 }
1715
1716 /* We can't stop this system call at this point, so just pretend we succeeded */
1717 error = 0;
1718 } else {
1719 os_reason_free(exec_failure_reason);
1720 exec_failure_reason = OS_REASON_NULL;
1721 }
1722
1723 done:
1724 if (load_result.threadstate) {
1725 kfree_data(load_result.threadstate, load_result.threadstate_sz);
1726 load_result.threadstate = NULL;
1727 }
1728
1729 bad:
1730 /* If we hit this, we likely would have leaked an exit reason */
1731 assert(exec_failure_reason == OS_REASON_NULL);
1732 return error;
1733 }
1734
1735
1736
1737
1738 /*
1739 * Our image activator table; this is the table of the image types we are
1740 * capable of loading. We list them in order of preference to ensure the
1741 * fastest image load speed.
1742 *
1743 * XXX hardcoded, for now; should use linker sets
1744 */
1745 struct execsw {
1746 int(*const ex_imgact)(struct image_params *);
1747 const char *ex_name;
1748 }const execsw[] = {
1749 { exec_mach_imgact, "Mach-o Binary" },
1750 { exec_fat_imgact, "Fat Binary" },
1751 { exec_shell_imgact, "Interpreter Script" },
1752 { NULL, NULL}
1753 };
1754
1755
1756 /*
1757 * exec_activate_image
1758 *
1759 * Description: Iterate through the available image activators, and activate
1760 * the image associated with the imgp structure. We start with
1761 * the activator for Mach-o binaries followed by that for Fat binaries
1762 * for Interpreter scripts.
1763 *
1764 * Parameters: struct image_params * Image parameter block
1765 *
1766 * Returns: 0 Success
1767 * ENOEXEC No activator for image.
1768 * EBADEXEC The executable is corrupt/unknown
1769 * execargs_alloc:EINVAL Invalid argument
1770 * execargs_alloc:EACCES Permission denied
1771 * execargs_alloc:EINTR Interrupted function
1772 * execargs_alloc:ENOMEM Not enough space
1773 * exec_save_path:EFAULT Bad address
1774 * exec_save_path:ENAMETOOLONG Filename too long
1775 * exec_check_permissions:EACCES Permission denied
1776 * exec_check_permissions:ENOEXEC Executable file format error
1777 * exec_check_permissions:ETXTBSY Text file busy [misuse of error code]
1778 * exec_check_permissions:???
1779 * namei:???
1780 * vn_rdwr:??? [anything vn_rdwr can return]
1781 * <ex_imgact>:??? [anything an imgact can return]
1782 * EDEADLK Process is being terminated
1783 */
1784 static int
exec_activate_image(struct image_params * imgp)1785 exec_activate_image(struct image_params *imgp)
1786 {
1787 struct nameidata *ndp = NULL;
1788 const char *excpath;
1789 int error;
1790 int resid;
1791 int once = 1; /* save SGUID-ness for interpreted files */
1792 int i;
1793 int itercount = 0;
1794 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
1795
1796 error = execargs_alloc(imgp);
1797 if (error) {
1798 goto bad_notrans;
1799 }
1800
1801 error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1802 if (error) {
1803 goto bad_notrans;
1804 }
1805
1806 /* Use excpath, which contains the copyin-ed exec path */
1807 DTRACE_PROC1(exec, uintptr_t, excpath);
1808
1809 ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1810
1811 NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
1812 UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
1813
1814 again:
1815 error = namei(ndp);
1816 if (error) {
1817 if (error == ERESTART) {
1818 error = EINTR;
1819 }
1820 goto bad_notrans;
1821 }
1822 imgp->ip_ndp = ndp; /* successful namei(); call nameidone() later */
1823 imgp->ip_vp = ndp->ni_vp; /* if set, need to vnode_put() at some point */
1824
1825 /*
1826 * Before we start the transition from binary A to binary B, make
1827 * sure another thread hasn't started exiting the process. We grab
1828 * the proc lock to check p_lflag initially, and the transition
1829 * mechanism ensures that the value doesn't change after we release
1830 * the lock.
1831 */
1832 proc_lock(p);
1833 if (p->p_lflag & P_LEXIT) {
1834 error = EDEADLK;
1835 proc_unlock(p);
1836 goto bad_notrans;
1837 }
1838 error = proc_transstart(p, 1, 0);
1839 proc_unlock(p);
1840 if (error) {
1841 goto bad_notrans;
1842 }
1843
1844 error = exec_check_permissions(imgp);
1845 if (error) {
1846 goto bad;
1847 }
1848
1849 /* Copy; avoid invocation of an interpreter overwriting the original */
1850 if (once) {
1851 once = 0;
1852 *imgp->ip_origvattr = *imgp->ip_vattr;
1853 }
1854
1855 error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
1856 UIO_SYSSPACE, IO_NODELOCKED,
1857 vfs_context_ucred(imgp->ip_vfs_context),
1858 &resid, vfs_context_proc(imgp->ip_vfs_context));
1859 if (error) {
1860 goto bad;
1861 }
1862
1863 if (resid) {
1864 memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
1865 }
1866
1867 encapsulated_binary:
1868 /* Limit the number of iterations we will attempt on each binary */
1869 if (++itercount > EAI_ITERLIMIT) {
1870 error = EBADEXEC;
1871 goto bad;
1872 }
1873 error = -1;
1874 for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
1875 error = (*execsw[i].ex_imgact)(imgp);
1876
1877 switch (error) {
1878 /* case -1: not claimed: continue */
1879 case -2: /* Encapsulated binary, imgp->ip_XXX set for next iteration */
1880 goto encapsulated_binary;
1881
1882 case -3: /* Interpreter */
1883 #if CONFIG_MACF
1884 /*
1885 * Copy the script label for later use. Note that
1886 * the label can be different when the script is
1887 * actually read by the interpreter.
1888 */
1889 if (imgp->ip_scriptlabelp) {
1890 mac_vnode_label_free(imgp->ip_scriptlabelp);
1891 imgp->ip_scriptlabelp = NULL;
1892 }
1893 imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
1894 if (imgp->ip_scriptlabelp == NULL) {
1895 error = ENOMEM;
1896 break;
1897 }
1898 mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
1899 imgp->ip_scriptlabelp);
1900
1901 /*
1902 * Take a ref of the script vnode for later use.
1903 */
1904 if (imgp->ip_scriptvp) {
1905 vnode_put(imgp->ip_scriptvp);
1906 imgp->ip_scriptvp = NULLVP;
1907 }
1908 if (vnode_getwithref(imgp->ip_vp) == 0) {
1909 imgp->ip_scriptvp = imgp->ip_vp;
1910 }
1911 #endif
1912
1913 nameidone(ndp);
1914
1915 vnode_put(imgp->ip_vp);
1916 imgp->ip_vp = NULL; /* already put */
1917 imgp->ip_ndp = NULL; /* already nameidone */
1918
1919 /* Use excpath, which exec_shell_imgact reset to the interpreter */
1920 NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
1921 UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
1922
1923 proc_transend(p, 0);
1924 goto again;
1925
1926 default:
1927 break;
1928 }
1929 }
1930
1931 if (error == -1) {
1932 error = ENOEXEC;
1933 } else if (error == 0) {
1934 if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
1935 AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
1936 }
1937
1938 /*
1939 * Call out to allow 3rd party notification of exec.
1940 * Ignore result of kauth_authorize_fileop call.
1941 */
1942 if (kauth_authorize_fileop_has_listeners()) {
1943 kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
1944 KAUTH_FILEOP_EXEC,
1945 (uintptr_t)ndp->ni_vp, 0);
1946 }
1947 }
1948 bad:
1949 proc_transend(p, 0);
1950
1951 bad_notrans:
1952 if (imgp->ip_strings) {
1953 execargs_free(imgp);
1954 }
1955 if (imgp->ip_ndp) {
1956 nameidone(imgp->ip_ndp);
1957 }
1958 kfree_type(struct nameidata, ndp);
1959
1960 return error;
1961 }
1962
1963 /*
1964 * exec_validate_spawnattr_policy
1965 *
1966 * Description: Validates the entitlements required to set the apptype.
1967 *
1968 * Parameters: int psa_apptype posix spawn attribute apptype
1969 *
1970 * Returns: 0 Success
1971 * EPERM Failure
1972 */
1973 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)1974 exec_validate_spawnattr_policy(int psa_apptype)
1975 {
1976 if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
1977 int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
1978 if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
1979 if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
1980 return EPERM;
1981 }
1982 }
1983 }
1984
1985 return 0;
1986 }
1987
1988 /*
1989 * exec_handle_spawnattr_policy
1990 *
1991 * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
1992 *
1993 * Parameters: proc_t p process to apply attributes to
1994 * int psa_apptype posix spawn attribute apptype
1995 *
1996 * Returns: 0 Success
1997 */
1998 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)1999 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2000 task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2001 {
2002 int apptype = TASK_APPTYPE_NONE;
2003 int qos_clamp = THREAD_QOS_UNSPECIFIED;
2004 task_role_t role = TASK_UNSPECIFIED;
2005
2006 if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2007 int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2008
2009 switch (proctype) {
2010 case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2011 apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2012 break;
2013 case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2014 apptype = TASK_APPTYPE_DAEMON_STANDARD;
2015 break;
2016 case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2017 apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2018 break;
2019 case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2020 apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2021 break;
2022 case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2023 apptype = TASK_APPTYPE_APP_DEFAULT;
2024 break;
2025 case POSIX_SPAWN_PROC_TYPE_DRIVER:
2026 apptype = TASK_APPTYPE_DRIVER;
2027 break;
2028 default:
2029 apptype = TASK_APPTYPE_NONE;
2030 /* TODO: Should an invalid value here fail the spawn? */
2031 break;
2032 }
2033 }
2034
2035 if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2036 switch (psa_qos_clamp) {
2037 case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2038 qos_clamp = THREAD_QOS_UTILITY;
2039 break;
2040 case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2041 qos_clamp = THREAD_QOS_BACKGROUND;
2042 break;
2043 case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2044 qos_clamp = THREAD_QOS_MAINTENANCE;
2045 break;
2046 default:
2047 qos_clamp = THREAD_QOS_UNSPECIFIED;
2048 /* TODO: Should an invalid value here fail the spawn? */
2049 break;
2050 }
2051 }
2052
2053 if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2054 proc_darwin_role_to_task_role(psa_darwin_role, &role);
2055 }
2056
2057 if (apptype != TASK_APPTYPE_NONE ||
2058 qos_clamp != THREAD_QOS_UNSPECIFIED ||
2059 role != TASK_UNSPECIFIED ||
2060 port_actions->portwatch_count) {
2061 proc_set_task_spawnpolicy(p->task, thread, apptype, qos_clamp, role,
2062 port_actions->portwatch_array, port_actions->portwatch_count);
2063 }
2064
2065 if (port_actions->registered_count) {
2066 if (mach_ports_register(p->task, port_actions->registered_array,
2067 port_actions->registered_count)) {
2068 return EINVAL;
2069 }
2070 /* mach_ports_register() consumed the array */
2071 port_actions->registered_array = NULL;
2072 port_actions->registered_count = 0;
2073 }
2074
2075 return 0;
2076 }
2077
2078 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2079 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2080 {
2081 if (port_actions->portwatch_array) {
2082 for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2083 ipc_port_t port = NULL;
2084 if ((port = port_actions->portwatch_array[i]) != NULL) {
2085 ipc_port_release_send(port);
2086 }
2087 }
2088 kfree_type(ipc_port_t, port_actions->portwatch_count,
2089 port_actions->portwatch_array);
2090 }
2091
2092 if (port_actions->registered_array) {
2093 for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2094 ipc_port_t port = NULL;
2095 if ((port = port_actions->registered_array[i]) != NULL) {
2096 ipc_port_release_send(port);
2097 }
2098 }
2099 kfree_type(ipc_port_t, port_actions->registered_count,
2100 port_actions->registered_array);
2101 }
2102 }
2103
2104 /*
2105 * exec_handle_port_actions
2106 *
2107 * Description: Go through the _posix_port_actions_t contents,
2108 * calling task_set_special_port, task_set_exception_ports
2109 * and/or audit_session_spawnjoin for the current task.
2110 *
2111 * Parameters: struct image_params * Image parameter block
2112 *
2113 * Returns: 0 Success
2114 * EINVAL Failure
2115 * ENOTSUP Illegal posix_spawn attr flag was set
2116 */
2117 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2118 exec_handle_port_actions(struct image_params *imgp,
2119 struct exec_port_actions *actions)
2120 {
2121 _posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2122 #if CONFIG_AUDIT
2123 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2124 #endif
2125 _ps_port_action_t *act = NULL;
2126 task_t task = get_threadtask(imgp->ip_new_thread);
2127 ipc_port_t port = NULL;
2128 errno_t ret = 0;
2129 int i, portwatch_i = 0, registered_i = 0;
2130 kern_return_t kr;
2131 boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2132 boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2133 int ptrauth_task_port_count = 0;
2134 boolean_t suid_cred_specified = FALSE;
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
2159 case PSPA_PTRAUTH_TASK_PORT:
2160 if (++ptrauth_task_port_count > 1) {
2161 ret = EINVAL;
2162 goto done;
2163 }
2164 break;
2165
2166 case PSPA_SUID_CRED:
2167 /* Only a single suid credential can be specified. */
2168 if (suid_cred_specified) {
2169 ret = EINVAL;
2170 goto done;
2171 }
2172 suid_cred_specified = TRUE;
2173 break;
2174
2175 default:
2176 ret = EINVAL;
2177 goto done;
2178 }
2179 }
2180
2181 if (actions->portwatch_count) {
2182 if (in_exec && task_has_watchport_boost) {
2183 ret = EINVAL;
2184 goto done;
2185 }
2186 actions->portwatch_array = kalloc_type(ipc_port_t,
2187 actions->portwatch_count, Z_WAITOK | Z_ZERO);
2188 if (actions->portwatch_array == NULL) {
2189 ret = ENOMEM;
2190 goto done;
2191 }
2192 }
2193
2194 if (actions->registered_count) {
2195 actions->registered_array = kalloc_type(ipc_port_t,
2196 actions->registered_count, Z_WAITOK | Z_ZERO);
2197 if (actions->registered_array == NULL) {
2198 ret = ENOMEM;
2199 goto done;
2200 }
2201 }
2202
2203 for (i = 0; i < pacts->pspa_count; i++) {
2204 act = &pacts->pspa_actions[i];
2205
2206 if (MACH_PORT_VALID(act->new_port)) {
2207 kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2208 act->new_port, MACH_MSG_TYPE_COPY_SEND,
2209 (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2210
2211 if (kr != KERN_SUCCESS) {
2212 ret = EINVAL;
2213 goto done;
2214 }
2215 } else {
2216 /* it's NULL or DEAD */
2217 port = CAST_MACH_NAME_TO_PORT(act->new_port);
2218 }
2219
2220 switch (act->port_type) {
2221 case PSPA_SPECIAL:
2222 kr = task_set_special_port(task, act->which, port);
2223
2224 if (kr != KERN_SUCCESS) {
2225 ret = EINVAL;
2226 }
2227 break;
2228
2229 case PSPA_EXCEPTION:
2230 kr = task_set_exception_ports(task, act->mask, port,
2231 act->behavior, act->flavor);
2232 if (kr != KERN_SUCCESS) {
2233 ret = EINVAL;
2234 }
2235 break;
2236 #if CONFIG_AUDIT
2237 case PSPA_AU_SESSION:
2238 ret = audit_session_spawnjoin(p, task, port);
2239 if (ret) {
2240 /* audit_session_spawnjoin() has already dropped the reference in case of error. */
2241 goto done;
2242 }
2243
2244 break;
2245 #endif
2246 case PSPA_IMP_WATCHPORTS:
2247 if (actions->portwatch_array) {
2248 /* hold on to this till end of spawn */
2249 actions->portwatch_array[portwatch_i++] = port;
2250 } else {
2251 ipc_port_release_send(port);
2252 }
2253 break;
2254 case PSPA_REGISTERED_PORTS:
2255 /* hold on to this till end of spawn */
2256 actions->registered_array[registered_i++] = port;
2257 break;
2258
2259 case PSPA_PTRAUTH_TASK_PORT:
2260 #if defined(HAS_APPLE_PAC)
2261 {
2262 task_t ptr_auth_task = convert_port_to_task(port);
2263
2264 if (ptr_auth_task == TASK_NULL) {
2265 ret = EINVAL;
2266 break;
2267 }
2268
2269 imgp->ip_inherited_shared_region_id =
2270 task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
2271 &imgp->ip_inherited_jop_pid);
2272
2273 /* Deallocate task ref returned by convert_port_to_task */
2274 task_deallocate(ptr_auth_task);
2275 }
2276 #endif /* HAS_APPLE_PAC */
2277
2278 /* consume the port right in case of success */
2279 ipc_port_release_send(port);
2280 break;
2281
2282 case PSPA_SUID_CRED:
2283 imgp->ip_sc_port = port;
2284 break;
2285
2286 default:
2287 ret = EINVAL;
2288 break;
2289 }
2290
2291 if (ret) {
2292 /* action failed, so release port resources */
2293 ipc_port_release_send(port);
2294 break;
2295 }
2296 }
2297
2298 done:
2299 if (0 != ret) {
2300 DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2301 }
2302 return ret;
2303 }
2304
2305 /*
2306 * exec_handle_file_actions
2307 *
2308 * Description: Go through the _posix_file_actions_t contents applying the
2309 * open, close, and dup2 operations to the open file table for
2310 * the current process.
2311 *
2312 * Parameters: struct image_params * Image parameter block
2313 *
2314 * Returns: 0 Success
2315 * ???
2316 *
2317 * Note: Actions are applied in the order specified, with the credential
2318 * of the parent process. This is done to permit the parent
2319 * process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
2320 * the child following operations the child may in fact not be
2321 * normally permitted to perform.
2322 */
2323 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)2324 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
2325 {
2326 int error = 0;
2327 int action;
2328 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2329 _posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
2330 int ival[2]; /* dummy retval for system calls) */
2331 #if CONFIG_AUDIT
2332 struct uthread *uthread = current_uthread();
2333 #endif
2334
2335 for (action = 0; action < px_sfap->psfa_act_count; action++) {
2336 _psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2337
2338 switch (psfa->psfaa_type) {
2339 case PSFA_OPEN: {
2340 /*
2341 * Open is different, in that it requires the use of
2342 * a path argument, which is normally copied in from
2343 * user space; because of this, we have to support an
2344 * open from kernel space that passes an address space
2345 * context of UIO_SYSSPACE, and casts the address
2346 * argument to a user_addr_t.
2347 */
2348 struct vnode_attr *vap;
2349 struct nameidata *ndp;
2350 int mode = psfa->psfaa_openargs.psfao_mode;
2351 int origfd;
2352 struct {
2353 struct vnode_attr va;
2354 struct nameidata nd;
2355 } *__open_data;
2356
2357 __open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
2358 if (__open_data == NULL) {
2359 error = ENOMEM;
2360 break;
2361 }
2362
2363 vap = &__open_data->va;
2364 ndp = &__open_data->nd;
2365
2366 VATTR_INIT(vap);
2367 /* Mask off all but regular access permissions */
2368 mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
2369 VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
2370
2371 AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
2372
2373 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2374 CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
2375 imgp->ip_vfs_context);
2376
2377 error = open1(imgp->ip_vfs_context, ndp,
2378 psfa->psfaa_openargs.psfao_oflag,
2379 vap, NULL, NULL, &origfd);
2380
2381 kfree_type(typeof(*__open_data), __open_data);
2382
2383 AUDIT_SUBCALL_EXIT(uthread, error);
2384
2385 /*
2386 * If there's an error, or we get the right fd by
2387 * accident, then drop out here. This is easier than
2388 * reworking all the open code to preallocate fd
2389 * slots, and internally taking one as an argument.
2390 */
2391 if (error || origfd == psfa->psfaa_filedes) {
2392 break;
2393 }
2394
2395 /*
2396 * If we didn't fall out from an error, we ended up
2397 * with the wrong fd; so now we've got to try to dup2
2398 * it to the right one.
2399 */
2400 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2401 error = dup2(p, origfd, psfa->psfaa_filedes, ival);
2402 AUDIT_SUBCALL_EXIT(uthread, error);
2403 if (error) {
2404 break;
2405 }
2406
2407 /*
2408 * Finally, close the original fd.
2409 */
2410 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2411 error = close_nocancel(p, origfd);
2412 AUDIT_SUBCALL_EXIT(uthread, error);
2413 }
2414 break;
2415
2416 case PSFA_DUP2: {
2417 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2418 error = dup2(p, psfa->psfaa_filedes,
2419 psfa->psfaa_dup2args.psfad_newfiledes, ival);
2420 AUDIT_SUBCALL_EXIT(uthread, error);
2421 }
2422 break;
2423
2424 case PSFA_FILEPORT_DUP2: {
2425 ipc_port_t port;
2426 kern_return_t kr;
2427 int origfd;
2428
2429 if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
2430 error = EINVAL;
2431 break;
2432 }
2433
2434 kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2435 psfa->psfaa_fileport, MACH_MSG_TYPE_COPY_SEND,
2436 (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2437
2438 if (kr != KERN_SUCCESS) {
2439 error = EINVAL;
2440 break;
2441 }
2442
2443 error = fileport_makefd(p, port, 0, &origfd);
2444
2445 if (IPC_PORT_NULL != port) {
2446 ipc_port_release_send(port);
2447 }
2448
2449 if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
2450 break;
2451 }
2452
2453 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2454 error = dup2(p, origfd,
2455 psfa->psfaa_dup2args.psfad_newfiledes, ival);
2456 AUDIT_SUBCALL_EXIT(uthread, error);
2457 if (error) {
2458 break;
2459 }
2460
2461 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2462 error = close_nocancel(p, origfd);
2463 AUDIT_SUBCALL_EXIT(uthread, error);
2464 }
2465 break;
2466
2467 case PSFA_CLOSE: {
2468 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2469 error = close_nocancel(p, psfa->psfaa_filedes);
2470 AUDIT_SUBCALL_EXIT(uthread, error);
2471 }
2472 break;
2473
2474 case PSFA_INHERIT: {
2475 struct fileproc *fp;
2476
2477 /*
2478 * Check to see if the descriptor exists, and
2479 * ensure it's -not- marked as close-on-exec.
2480 *
2481 * Attempting to "inherit" a guarded fd will
2482 * result in a error.
2483 */
2484
2485 proc_fdlock(p);
2486 if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
2487 error = EBADF;
2488 } else if (fp->fp_guard_attrs) {
2489 error = fp_guard_exception(p, psfa->psfaa_filedes,
2490 fp, kGUARD_EXC_NOCLOEXEC);
2491 } else {
2492 fp->fp_flags &= ~FP_CLOEXEC;
2493 error = 0;
2494 }
2495 proc_fdunlock(p);
2496 }
2497 break;
2498
2499 case PSFA_CHDIR: {
2500 /*
2501 * Chdir is different, in that it requires the use of
2502 * a path argument, which is normally copied in from
2503 * user space; because of this, we have to support a
2504 * chdir from kernel space that passes an address space
2505 * context of UIO_SYSSPACE, and casts the address
2506 * argument to a user_addr_t.
2507 */
2508 struct nameidata *nd;
2509 nd = kalloc_type(struct nameidata,
2510 Z_WAITOK | Z_ZERO | Z_NOFAIL);
2511
2512 AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
2513 NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2514 CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
2515 imgp->ip_vfs_context);
2516
2517 error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
2518 kfree_type(struct nameidata, nd);
2519 AUDIT_SUBCALL_EXIT(uthread, error);
2520 }
2521 break;
2522
2523 case PSFA_FCHDIR: {
2524 struct fchdir_args fchdira;
2525
2526 fchdira.fd = psfa->psfaa_filedes;
2527
2528 AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
2529 error = fchdir(p, &fchdira, ival);
2530 AUDIT_SUBCALL_EXIT(uthread, error);
2531 }
2532 break;
2533
2534 default:
2535 error = EINVAL;
2536 break;
2537 }
2538
2539 /* All file actions failures are considered fatal, per POSIX */
2540
2541 if (error) {
2542 if (PSFA_OPEN == psfa->psfaa_type) {
2543 DTRACE_PROC1(spawn__open__failure, uintptr_t,
2544 psfa->psfaa_openargs.psfao_path);
2545 } else {
2546 DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
2547 }
2548 break;
2549 }
2550 }
2551
2552 if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
2553 return error;
2554 }
2555
2556 /*
2557 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
2558 * this spawn only) as if "close on exec" is the default
2559 * disposition of all pre-existing file descriptors. In this case,
2560 * the list of file descriptors mentioned in the file actions
2561 * are the only ones that can be inherited, so mark them now.
2562 *
2563 * The actual closing part comes later, in fdt_exec().
2564 */
2565 proc_fdlock(p);
2566 for (action = 0; action < px_sfap->psfa_act_count; action++) {
2567 _psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2568 int fd = psfa->psfaa_filedes;
2569
2570 switch (psfa->psfaa_type) {
2571 case PSFA_DUP2:
2572 case PSFA_FILEPORT_DUP2:
2573 fd = psfa->psfaa_dup2args.psfad_newfiledes;
2574 OS_FALLTHROUGH;
2575 case PSFA_OPEN:
2576 case PSFA_INHERIT:
2577 *fdflags(p, fd) |= UF_INHERIT;
2578 break;
2579
2580 case PSFA_CLOSE:
2581 case PSFA_CHDIR:
2582 case PSFA_FCHDIR:
2583 /*
2584 * Although PSFA_FCHDIR does have a file descriptor, it is not
2585 * *creating* one, thus we do not automatically mark it for
2586 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
2587 * wishes it to be inherited should use the PSFA_INHERIT action
2588 * explicitly.
2589 */
2590 break;
2591 }
2592 }
2593 proc_fdunlock(p);
2594
2595 return 0;
2596 }
2597
2598 #if CONFIG_MACF
2599 /*
2600 * Check that the extension's data is within the bounds of the
2601 * allocation storing all extensions' data
2602 */
2603 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)2604 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
2605 const _ps_mac_policy_extension_t *ext)
2606 {
2607 uint64_t dataend;
2608
2609 if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
2610 return EOVERFLOW;
2611 }
2612 if (__improbable(dataend > px_s->datalen)) {
2613 return EINVAL;
2614 }
2615
2616 return 0;
2617 }
2618
2619 /*
2620 * exec_spawnattr_getmacpolicyinfo
2621 */
2622 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)2623 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
2624 {
2625 const struct ip_px_smpx_s *px_s = macextensions;
2626 const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
2627 int i;
2628
2629 if (px_s == NULL) {
2630 return NULL;
2631 }
2632
2633 psmx = px_s->array;
2634 if (psmx == NULL) {
2635 return NULL;
2636 }
2637
2638 for (i = 0; i < psmx->psmx_count; i++) {
2639 const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
2640 if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
2641 if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
2642 panic("invalid mac policy extension data");
2643 }
2644 if (lenp != NULL) {
2645 *lenp = (size_t)extension->datalen;
2646 }
2647 return (void *)((uintptr_t)px_s->data + extension->dataoff);
2648 }
2649 }
2650
2651 if (lenp != NULL) {
2652 *lenp = 0;
2653 }
2654 return NULL;
2655 }
2656
2657 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)2658 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
2659 struct ip_px_smpx_s *pxsp)
2660 {
2661 _posix_spawn_mac_policy_extensions_t psmx = NULL;
2662 uint8_t *data = NULL;
2663 uint64_t datalen = 0;
2664 uint64_t dataoff = 0;
2665 int error = 0;
2666
2667 bzero(pxsp, sizeof(*pxsp));
2668
2669 if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
2670 px_args->mac_extensions_size > PAGE_SIZE) {
2671 error = EINVAL;
2672 goto bad;
2673 }
2674
2675 psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
2676 if (psmx == NULL) {
2677 error = ENOMEM;
2678 goto bad;
2679 }
2680
2681 error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
2682 if (error) {
2683 goto bad;
2684 }
2685
2686 size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
2687 if (extsize == 0 || extsize > px_args->mac_extensions_size) {
2688 error = EINVAL;
2689 goto bad;
2690 }
2691
2692 for (int i = 0; i < psmx->psmx_count; i++) {
2693 _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
2694 if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
2695 error = EINVAL;
2696 goto bad;
2697 }
2698 if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
2699 error = ENOMEM;
2700 goto bad;
2701 }
2702 }
2703
2704 data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
2705 if (data == NULL) {
2706 error = ENOMEM;
2707 goto bad;
2708 }
2709
2710 for (int i = 0; i < psmx->psmx_count; i++) {
2711 _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
2712
2713 #if !__LP64__
2714 if (extension->data > UINT32_MAX) {
2715 goto bad;
2716 }
2717 #endif
2718 error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
2719 if (error) {
2720 error = ENOMEM;
2721 goto bad;
2722 }
2723 extension->dataoff = dataoff;
2724 dataoff += extension->datalen;
2725 }
2726
2727 pxsp->array = psmx;
2728 pxsp->data = data;
2729 pxsp->datalen = datalen;
2730 return 0;
2731
2732 bad:
2733 kfree_data(psmx, px_args->mac_extensions_size);
2734 kfree_data(data, (vm_size_t)datalen);
2735 return error;
2736 }
2737 #endif /* CONFIG_MACF */
2738
2739 #if CONFIG_COALITIONS
2740 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])2741 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
2742 {
2743 for (int c = 0; c < COALITION_NUM_TYPES; c++) {
2744 if (coal[c]) {
2745 coalition_remove_active(coal[c]);
2746 coalition_release(coal[c]);
2747 }
2748 }
2749 }
2750 #endif
2751
2752 #if CONFIG_PERSONAS
2753 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)2754 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
2755 {
2756 int error = 0;
2757 struct persona *persona = NULL;
2758 int verify = px_persona->pspi_flags & POSIX_SPAWN_PERSONA_FLAGS_VERIFY;
2759
2760 if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
2761 return EPERM;
2762 }
2763
2764 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
2765 if (px_persona->pspi_ngroups > NGROUPS_MAX) {
2766 return EINVAL;
2767 }
2768 }
2769
2770 persona = persona_lookup(px_persona->pspi_id);
2771 if (!persona) {
2772 error = ESRCH;
2773 goto out;
2774 }
2775
2776 if (verify) {
2777 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
2778 if (px_persona->pspi_uid != persona_get_uid(persona)) {
2779 error = EINVAL;
2780 goto out;
2781 }
2782 }
2783 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
2784 if (px_persona->pspi_gid != persona_get_gid(persona)) {
2785 error = EINVAL;
2786 goto out;
2787 }
2788 }
2789 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
2790 size_t ngroups = 0;
2791 gid_t groups[NGROUPS_MAX];
2792
2793 if (persona_get_groups(persona, &ngroups, groups,
2794 px_persona->pspi_ngroups) != 0) {
2795 error = EINVAL;
2796 goto out;
2797 }
2798 if (ngroups != px_persona->pspi_ngroups) {
2799 error = EINVAL;
2800 goto out;
2801 }
2802 while (ngroups--) {
2803 if (px_persona->pspi_groups[ngroups] != groups[ngroups]) {
2804 error = EINVAL;
2805 goto out;
2806 }
2807 }
2808 if (px_persona->pspi_gmuid != persona_get_gmuid(persona)) {
2809 error = EINVAL;
2810 goto out;
2811 }
2812 }
2813 }
2814
2815 out:
2816 if (persona) {
2817 persona_put(persona);
2818 }
2819
2820 return error;
2821 }
2822
2823 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)2824 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
2825 {
2826 int ret;
2827 kauth_cred_t cred;
2828 struct persona *persona = NULL;
2829 int override = !!(px_persona->pspi_flags & POSIX_SPAWN_PERSONA_FLAGS_OVERRIDE);
2830
2831 if (!override) {
2832 return persona_proc_adopt_id(p, px_persona->pspi_id, NULL);
2833 }
2834
2835 /*
2836 * we want to spawn into the given persona, but we want to override
2837 * the kauth with a different UID/GID combo
2838 */
2839 persona = persona_lookup(px_persona->pspi_id);
2840 if (!persona) {
2841 return ESRCH;
2842 }
2843
2844 cred = persona_get_cred(persona);
2845 if (!cred) {
2846 ret = EINVAL;
2847 goto out;
2848 }
2849
2850 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
2851 cred = kauth_cred_setresuid(cred,
2852 px_persona->pspi_uid,
2853 px_persona->pspi_uid,
2854 px_persona->pspi_uid,
2855 KAUTH_UID_NONE);
2856 }
2857
2858 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
2859 cred = kauth_cred_setresgid(cred,
2860 px_persona->pspi_gid,
2861 px_persona->pspi_gid,
2862 px_persona->pspi_gid);
2863 }
2864
2865 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
2866 cred = kauth_cred_setgroups(cred,
2867 px_persona->pspi_groups,
2868 px_persona->pspi_ngroups,
2869 px_persona->pspi_gmuid);
2870 }
2871
2872 ret = persona_proc_adopt(p, persona, cred);
2873
2874 out:
2875 persona_put(persona);
2876 return ret;
2877 }
2878 #endif
2879
2880 #if __arm64__
2881 #if DEVELOPMENT || DEBUG
2882 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
2883 LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
2884
2885 __startup_func
2886 static void
legacy_footprint_entitlement_mode_init(void)2887 legacy_footprint_entitlement_mode_init(void)
2888 {
2889 /*
2890 * legacy_footprint_entitlement_mode specifies the behavior we want associated
2891 * with the entitlement. The supported modes are:
2892 *
2893 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
2894 * Indicates that we want every process to have the memory accounting
2895 * that is available in iOS 12.0 and beyond.
2896 *
2897 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
2898 * Indicates that for every process that has the 'legacy footprint entitlement',
2899 * we want to give it the old iOS 11.0 accounting behavior which accounted some
2900 * of the process's memory to the kernel.
2901 *
2902 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
2903 * Indicates that for every process that has the 'legacy footprint entitlement',
2904 * we want it to have a higher memory limit which will help them acclimate to the
2905 * iOS 12.0 (& beyond) accounting behavior that does the right accounting.
2906 * The bonus added to the system-wide task limit to calculate this higher memory limit
2907 * is available in legacy_footprint_bonus_mb.
2908 */
2909
2910 if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
2911 legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
2912 legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
2913 }
2914 }
2915 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
2916 #else
2917 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
2918 #endif
2919
2920 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)2921 proc_legacy_footprint_entitled(proc_t p, task_t task)
2922 {
2923 #pragma unused(p)
2924 boolean_t legacy_footprint_entitled;
2925
2926 switch (legacy_footprint_entitlement_mode) {
2927 case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
2928 /* the entitlement is ignored */
2929 break;
2930 case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
2931 /* the entitlement grants iOS11 legacy accounting */
2932 legacy_footprint_entitled = IOTaskHasEntitlement(task,
2933 "com.apple.private.memory.legacy_footprint");
2934 if (legacy_footprint_entitled) {
2935 task_set_legacy_footprint(task);
2936 }
2937 break;
2938 case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
2939 /* the entitlement grants a footprint limit increase */
2940 legacy_footprint_entitled = IOTaskHasEntitlement(task,
2941 "com.apple.private.memory.legacy_footprint");
2942 if (legacy_footprint_entitled) {
2943 task_set_extra_footprint_limit(task);
2944 }
2945 break;
2946 default:
2947 break;
2948 }
2949 }
2950
2951 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)2952 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
2953 {
2954 #pragma unused(p)
2955 boolean_t ios13extended_footprint_entitled;
2956
2957 /* the entitlement grants a footprint limit increase */
2958 ios13extended_footprint_entitled = IOTaskHasEntitlement(task,
2959 "com.apple.developer.memory.ios13extended_footprint");
2960 if (ios13extended_footprint_entitled) {
2961 task_set_ios13extended_footprint_limit(task);
2962 }
2963 }
2964 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)2965 proc_increased_memory_limit_entitled(proc_t p, task_t task)
2966 {
2967 static const char kIncreasedMemoryLimitEntitlement[] = "com.apple.developer.kernel.increased-memory-limit";
2968 bool entitled = false;
2969
2970 entitled = IOTaskHasEntitlement(task, kIncreasedMemoryLimitEntitlement);
2971 if (entitled) {
2972 memorystatus_act_on_entitled_task_limit(p);
2973 }
2974 }
2975
2976 /*
2977 * Check for any of the various entitlements that permit a higher
2978 * task footprint limit or alternate accounting and apply them.
2979 */
2980 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)2981 proc_footprint_entitlement_hacks(proc_t p, task_t task)
2982 {
2983 proc_legacy_footprint_entitled(p, task);
2984 proc_ios13extended_footprint_entitled(p, task);
2985 proc_increased_memory_limit_entitled(p, task);
2986 }
2987 #endif /* __arm64__ */
2988
2989 #if CONFIG_MACF
2990 /*
2991 * Processes with certain entitlements are granted a jumbo-size VM map.
2992 */
2993 static inline void
proc_apply_jit_and_jumbo_va_policies(proc_t p,task_t task)2994 proc_apply_jit_and_jumbo_va_policies(proc_t p, task_t task)
2995 {
2996 bool jit_entitled;
2997 jit_entitled = (mac_proc_check_map_anon(p, 0, 0, 0, MAP_JIT, NULL) == 0);
2998 if (jit_entitled || (IOTaskHasEntitlement(task,
2999 "com.apple.developer.kernel.extended-virtual-addressing"))) {
3000 vm_map_set_jumbo(get_task_map(task));
3001 if (jit_entitled) {
3002 vm_map_set_jit_entitled(get_task_map(task));
3003
3004 }
3005 }
3006 }
3007 #endif /* CONFIG_MACF */
3008
3009 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)3010 spawn_posix_cred_adopt(proc_t p,
3011 struct _posix_spawn_posix_cred_info *px_pcred_info)
3012 {
3013 int error = 0;
3014
3015 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3016 struct setgid_args args = {
3017 .gid = px_pcred_info->pspci_gid,
3018 };
3019 error = setgid(p, &args, NULL);
3020 if (error) {
3021 return error;
3022 }
3023 }
3024
3025 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3026 error = setgroups_internal(p,
3027 px_pcred_info->pspci_ngroups,
3028 px_pcred_info->pspci_groups,
3029 px_pcred_info->pspci_gmuid);
3030 if (error) {
3031 return error;
3032 }
3033 }
3034
3035 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3036 struct setuid_args args = {
3037 .uid = px_pcred_info->pspci_uid,
3038 };
3039 error = setuid(p, &args, NULL);
3040 if (error) {
3041 return error;
3042 }
3043 }
3044 return 0;
3045 }
3046
3047 /*
3048 * posix_spawn
3049 *
3050 * Parameters: uap->pid Pointer to pid return area
3051 * uap->fname File name to exec
3052 * uap->argp Argument list
3053 * uap->envp Environment list
3054 *
3055 * Returns: 0 Success
3056 * EINVAL Invalid argument
3057 * ENOTSUP Not supported
3058 * ENOEXEC Executable file format error
3059 * exec_activate_image:EINVAL Invalid argument
3060 * exec_activate_image:EACCES Permission denied
3061 * exec_activate_image:EINTR Interrupted function
3062 * exec_activate_image:ENOMEM Not enough space
3063 * exec_activate_image:EFAULT Bad address
3064 * exec_activate_image:ENAMETOOLONG Filename too long
3065 * exec_activate_image:ENOEXEC Executable file format error
3066 * exec_activate_image:ETXTBSY Text file busy [misuse of error code]
3067 * exec_activate_image:EAUTH Image decryption failed
3068 * exec_activate_image:EBADEXEC The executable is corrupt/unknown
3069 * exec_activate_image:???
3070 * mac_execve_enter:???
3071 *
3072 * TODO: Expect to need __mac_posix_spawn() at some point...
3073 * Handle posix_spawnattr_t
3074 * Handle posix_spawn_file_actions_t
3075 */
3076 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3077 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3078 {
3079 proc_t p = ap;
3080 user_addr_t pid = uap->pid;
3081 int ival[2]; /* dummy retval for setpgid() */
3082 char *subsystem_root_path = NULL;
3083 struct image_params *imgp = NULL;
3084 struct vnode_attr *vap = NULL;
3085 struct vnode_attr *origvap = NULL;
3086 struct uthread *uthread = 0; /* compiler complains if not set to 0*/
3087 int error, sig;
3088 int is_64 = IS_64BIT_PROCESS(p);
3089 struct vfs_context context;
3090 struct user__posix_spawn_args_desc px_args;
3091 struct _posix_spawnattr px_sa;
3092 _posix_spawn_file_actions_t px_sfap = NULL;
3093 _posix_spawn_port_actions_t px_spap = NULL;
3094 struct __kern_sigaction vec;
3095 boolean_t spawn_no_exec = FALSE;
3096 boolean_t proc_transit_set = TRUE;
3097 boolean_t exec_done = FALSE;
3098 struct exec_port_actions port_actions = { };
3099 vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3100 task_t old_task = current_task();
3101 task_t new_task = NULL;
3102 boolean_t should_release_proc_ref = FALSE;
3103 void *inherit = NULL;
3104 #if CONFIG_PERSONAS
3105 struct _posix_spawn_persona_info *px_persona = NULL;
3106 #endif
3107 struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3108 struct {
3109 struct image_params imgp;
3110 struct vnode_attr va;
3111 struct vnode_attr origva;
3112 } *__spawn_data;
3113
3114 /*
3115 * Allocate a big chunk for locals instead of using stack since these
3116 * structures are pretty big.
3117 */
3118 __spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3119 if (__spawn_data == NULL) {
3120 error = ENOMEM;
3121 goto bad;
3122 }
3123 imgp = &__spawn_data->imgp;
3124 vap = &__spawn_data->va;
3125 origvap = &__spawn_data->origva;
3126
3127 /* Initialize the common data in the image_params structure */
3128 imgp->ip_user_fname = uap->path;
3129 imgp->ip_user_argv = uap->argv;
3130 imgp->ip_user_envv = uap->envp;
3131 imgp->ip_vattr = vap;
3132 imgp->ip_origvattr = origvap;
3133 imgp->ip_vfs_context = &context;
3134 imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3135 imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3136 imgp->ip_mac_return = 0;
3137 imgp->ip_px_persona = NULL;
3138 imgp->ip_px_pcred_info = NULL;
3139 imgp->ip_cs_error = OS_REASON_NULL;
3140 imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3141 imgp->ip_subsystem_root_path = NULL;
3142 imgp->ip_inherited_shared_region_id = NULL;
3143 imgp->ip_inherited_jop_pid = 0;
3144
3145 if (uap->adesc != USER_ADDR_NULL) {
3146 if (is_64) {
3147 error = copyin(uap->adesc, &px_args, sizeof(px_args));
3148 } else {
3149 struct user32__posix_spawn_args_desc px_args32;
3150
3151 error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3152
3153 /*
3154 * Convert arguments descriptor from external 32 bit
3155 * representation to internal 64 bit representation
3156 */
3157 px_args.attr_size = px_args32.attr_size;
3158 px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3159 px_args.file_actions_size = px_args32.file_actions_size;
3160 px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3161 px_args.port_actions_size = px_args32.port_actions_size;
3162 px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3163 px_args.mac_extensions_size = px_args32.mac_extensions_size;
3164 px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3165 px_args.coal_info_size = px_args32.coal_info_size;
3166 px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3167 px_args.persona_info_size = px_args32.persona_info_size;
3168 px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3169 px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3170 px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3171 px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3172 px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3173 }
3174 if (error) {
3175 goto bad;
3176 }
3177
3178 if (px_args.attr_size != 0) {
3179 /*
3180 * We are not copying the port_actions pointer,
3181 * because we already have it from px_args.
3182 * This is a bit fragile: <rdar://problem/16427422>
3183 */
3184
3185 if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3186 goto bad;
3187 }
3188
3189 bzero((void *)((unsigned long) &px_sa + px_sa_offset), sizeof(px_sa) - px_sa_offset );
3190
3191 imgp->ip_px_sa = &px_sa;
3192 }
3193 if (px_args.file_actions_size != 0) {
3194 /* Limit file_actions to allowed number of open files */
3195 size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3196
3197 if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3198 maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3199 error = EINVAL;
3200 goto bad;
3201 }
3202
3203 px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3204 if (px_sfap == NULL) {
3205 error = ENOMEM;
3206 goto bad;
3207 }
3208 imgp->ip_px_sfa = px_sfap;
3209
3210 if ((error = copyin(px_args.file_actions, px_sfap,
3211 px_args.file_actions_size)) != 0) {
3212 goto bad;
3213 }
3214
3215 /* Verify that the action count matches the struct size */
3216 size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3217 if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3218 error = EINVAL;
3219 goto bad;
3220 }
3221 }
3222 if (px_args.port_actions_size != 0) {
3223 /* Limit port_actions to one page of data */
3224 if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3225 px_args.port_actions_size > PAGE_SIZE) {
3226 error = EINVAL;
3227 goto bad;
3228 }
3229
3230 px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3231 if (px_spap == NULL) {
3232 error = ENOMEM;
3233 goto bad;
3234 }
3235 imgp->ip_px_spa = px_spap;
3236
3237 if ((error = copyin(px_args.port_actions, px_spap,
3238 px_args.port_actions_size)) != 0) {
3239 goto bad;
3240 }
3241
3242 /* Verify that the action count matches the struct size */
3243 size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3244 if (pasize == 0 || pasize != px_args.port_actions_size) {
3245 error = EINVAL;
3246 goto bad;
3247 }
3248 }
3249 #if CONFIG_PERSONAS
3250 /* copy in the persona info */
3251 if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3252 /* for now, we need the exact same struct in user space */
3253 if (px_args.persona_info_size != sizeof(*px_persona)) {
3254 error = ERANGE;
3255 goto bad;
3256 }
3257
3258 px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3259 if (px_persona == NULL) {
3260 error = ENOMEM;
3261 goto bad;
3262 }
3263 imgp->ip_px_persona = px_persona;
3264
3265 if ((error = copyin(px_args.persona_info, px_persona,
3266 px_args.persona_info_size)) != 0) {
3267 goto bad;
3268 }
3269 if ((error = spawn_validate_persona(px_persona)) != 0) {
3270 goto bad;
3271 }
3272 }
3273 #endif
3274 /* copy in the posix cred info */
3275 if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
3276 /* for now, we need the exact same struct in user space */
3277 if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
3278 error = ERANGE;
3279 goto bad;
3280 }
3281
3282 if (!kauth_cred_issuser(kauth_cred_get())) {
3283 error = EPERM;
3284 goto bad;
3285 }
3286
3287 px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
3288 if (px_pcred_info == NULL) {
3289 error = ENOMEM;
3290 goto bad;
3291 }
3292 imgp->ip_px_pcred_info = px_pcred_info;
3293
3294 if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
3295 px_args.posix_cred_info_size)) != 0) {
3296 goto bad;
3297 }
3298
3299 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3300 if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
3301 error = EINVAL;
3302 goto bad;
3303 }
3304 }
3305 }
3306 #if CONFIG_MACF
3307 if (px_args.mac_extensions_size != 0) {
3308 if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
3309 goto bad;
3310 }
3311 }
3312 #endif /* CONFIG_MACF */
3313 if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
3314 /*
3315 * If a valid-looking subsystem root has been
3316 * specified...
3317 */
3318 if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
3319 /*
3320 * ...AND the parent has the entitlement, copy
3321 * the subsystem root path in.
3322 */
3323 subsystem_root_path = zalloc_flags(ZV_NAMEI,
3324 Z_WAITOK | Z_ZERO | Z_NOFAIL);
3325
3326 if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
3327 goto bad;
3328 }
3329
3330 /* Paranoia */
3331 subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
3332 }
3333 }
3334 }
3335
3336 /* set uthread to parent */
3337 uthread = current_uthread();
3338
3339 /*
3340 * <rdar://6640530>; this does not result in a behaviour change
3341 * relative to Leopard, so there should not be any existing code
3342 * which depends on it.
3343 */
3344
3345 if (imgp->ip_px_sa != NULL) {
3346 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
3347 if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
3348 imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
3349 }
3350 #if (DEVELOPMENT || DEBUG)
3351 if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
3352 imgp->ip_flags |= IMGPF_ALT_ROSETTA;
3353 }
3354 #endif
3355
3356 if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
3357 goto bad;
3358 }
3359 }
3360
3361 /*
3362 * If we don't have the extension flag that turns "posix_spawn()"
3363 * into "execve() with options", then we will be creating a new
3364 * process which does not inherit memory from the parent process,
3365 * which is one of the most expensive things about using fork()
3366 * and execve().
3367 */
3368 if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3369 /* Set the new task's coalition, if it is requested. */
3370 coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
3371 #if CONFIG_COALITIONS
3372 int i, ncoals;
3373 kern_return_t kr = KERN_SUCCESS;
3374 struct _posix_spawn_coalition_info coal_info;
3375 int coal_role[COALITION_NUM_TYPES];
3376
3377 if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
3378 goto do_fork1;
3379 }
3380
3381 memset(&coal_info, 0, sizeof(coal_info));
3382
3383 if (px_args.coal_info_size > sizeof(coal_info)) {
3384 px_args.coal_info_size = sizeof(coal_info);
3385 }
3386 error = copyin(px_args.coal_info,
3387 &coal_info, px_args.coal_info_size);
3388 if (error != 0) {
3389 goto bad;
3390 }
3391
3392 ncoals = 0;
3393 for (i = 0; i < COALITION_NUM_TYPES; i++) {
3394 uint64_t cid = coal_info.psci_info[i].psci_id;
3395 if (cid != 0) {
3396 /*
3397 * don't allow tasks which are not in a
3398 * privileged coalition to spawn processes
3399 * into coalitions other than their own
3400 */
3401 if (!task_is_in_privileged_coalition(p->task, i) &&
3402 !IOTaskHasEntitlement(p->task, COALITION_SPAWN_ENTITLEMENT)) {
3403 coal_dbg("ERROR: %d not in privilegd "
3404 "coalition of type %d",
3405 proc_getpid(p), i);
3406 spawn_coalitions_release_all(coal);
3407 error = EPERM;
3408 goto bad;
3409 }
3410
3411 coal_dbg("searching for coalition id:%llu", cid);
3412 /*
3413 * take a reference and activation on the
3414 * coalition to guard against free-while-spawn
3415 * races
3416 */
3417 coal[i] = coalition_find_and_activate_by_id(cid);
3418 if (coal[i] == COALITION_NULL) {
3419 coal_dbg("could not find coalition id:%llu "
3420 "(perhaps it has been terminated or reaped)", cid);
3421 /*
3422 * release any other coalition's we
3423 * may have a reference to
3424 */
3425 spawn_coalitions_release_all(coal);
3426 error = ESRCH;
3427 goto bad;
3428 }
3429 if (coalition_type(coal[i]) != i) {
3430 coal_dbg("coalition with id:%lld is not of type:%d"
3431 " (it's type:%d)", cid, i, coalition_type(coal[i]));
3432 error = ESRCH;
3433 goto bad;
3434 }
3435 coal_role[i] = coal_info.psci_info[i].psci_role;
3436 ncoals++;
3437 }
3438 }
3439 if (ncoals < COALITION_NUM_TYPES) {
3440 /*
3441 * If the user is attempting to spawn into a subset of
3442 * the known coalition types, then make sure they have
3443 * _at_least_ specified a resource coalition. If not,
3444 * the following fork1() call will implicitly force an
3445 * inheritance from 'p' and won't actually spawn the
3446 * new task into the coalitions the user specified.
3447 * (also the call to coalitions_set_roles will panic)
3448 */
3449 if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
3450 spawn_coalitions_release_all(coal);
3451 error = EINVAL;
3452 goto bad;
3453 }
3454 }
3455 do_fork1:
3456 #endif /* CONFIG_COALITIONS */
3457
3458 /*
3459 * note that this will implicitly inherit the
3460 * caller's persona (if it exists)
3461 */
3462 error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
3463 /* returns a thread and task reference */
3464
3465 if (error == 0) {
3466 new_task = get_threadtask(imgp->ip_new_thread);
3467 }
3468 #if CONFIG_COALITIONS
3469 /* set the roles of this task within each given coalition */
3470 if (error == 0) {
3471 kr = coalitions_set_roles(coal, new_task, coal_role);
3472 if (kr != KERN_SUCCESS) {
3473 error = EINVAL;
3474 }
3475 if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
3476 MACH_COALITION_ADOPT))) {
3477 for (i = 0; i < COALITION_NUM_TYPES; i++) {
3478 if (coal[i] != COALITION_NULL) {
3479 /*
3480 * On 32-bit targets, uniqueid
3481 * will get truncated to 32 bits
3482 */
3483 KDBG_RELEASE(MACHDBG_CODE(
3484 DBG_MACH_COALITION,
3485 MACH_COALITION_ADOPT),
3486 coalition_id(coal[i]),
3487 get_task_uniqueid(new_task));
3488 }
3489 }
3490 }
3491 }
3492
3493 /* drop our references and activations - fork1() now holds them */
3494 spawn_coalitions_release_all(coal);
3495 #endif /* CONFIG_COALITIONS */
3496 if (error != 0) {
3497 goto bad;
3498 }
3499 imgp->ip_flags |= IMGPF_SPAWN; /* spawn w/o exec */
3500 spawn_no_exec = TRUE; /* used in later tests */
3501 } else {
3502 /*
3503 * For execve case, create a new task and thread
3504 * which points to current_proc. The current_proc will point
3505 * to the new task after image activation and proc ref drain.
3506 *
3507 * proc (current_proc) <----- old_task (current_task)
3508 * ^ | ^
3509 * | | |
3510 * | ----------------------------------
3511 * |
3512 * --------- new_task (task marked as TF_EXEC_COPY)
3513 *
3514 * After image activation, the proc will point to the new task
3515 * and would look like following.
3516 *
3517 * proc (current_proc) <----- old_task (current_task, marked as TPF_DID_EXEC)
3518 * ^ |
3519 * | |
3520 * | ----------> new_task
3521 * | |
3522 * -----------------
3523 *
3524 * During exec any transition from new_task -> proc is fine, but don't allow
3525 * transition from proc->task, since it will modify old_task.
3526 */
3527 imgp->ip_new_thread = fork_create_child(old_task,
3528 NULL,
3529 p,
3530 FALSE,
3531 p->p_flag & P_LP64,
3532 task_get_64bit_data(old_task),
3533 TRUE);
3534 /* task and thread ref returned by fork_create_child */
3535 if (imgp->ip_new_thread == NULL) {
3536 error = ENOMEM;
3537 goto bad;
3538 }
3539
3540 new_task = get_threadtask(imgp->ip_new_thread);
3541 imgp->ip_flags |= IMGPF_EXEC;
3542 }
3543
3544 if (spawn_no_exec) {
3545 p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
3546
3547 /*
3548 * We had to wait until this point before firing the
3549 * proc:::create probe, otherwise p would not point to the
3550 * child process.
3551 */
3552 DTRACE_PROC1(create, proc_t, p);
3553 }
3554 assert(p != NULL);
3555
3556 if (subsystem_root_path) {
3557 /* If a subsystem root was specified, swap it in */
3558 char * old_subsystem_root_path = p->p_subsystem_root_path;
3559 p->p_subsystem_root_path = subsystem_root_path;
3560 subsystem_root_path = old_subsystem_root_path;
3561 }
3562
3563 /* We'll need the subsystem root for setting up Apple strings */
3564 imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
3565
3566 context.vc_thread = imgp->ip_new_thread;
3567 context.vc_ucred = proc_ucred(p); /* XXX must NOT be kauth_cred_get() */
3568
3569 /*
3570 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
3571 * to handle the file_actions.
3572 */
3573
3574 /* Has spawn file actions? */
3575 if (imgp->ip_px_sfa != NULL) {
3576 /*
3577 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
3578 * is handled in exec_handle_file_actions().
3579 */
3580 #if CONFIG_AUDIT
3581 /*
3582 * The file actions auditing can overwrite the upath of
3583 * AUE_POSIX_SPAWN audit record. Save the audit record.
3584 */
3585 struct kaudit_record *save_uu_ar = uthread->uu_ar;
3586 uthread->uu_ar = NULL;
3587 #endif
3588 error = exec_handle_file_actions(imgp,
3589 imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
3590 #if CONFIG_AUDIT
3591 /* Restore the AUE_POSIX_SPAWN audit record. */
3592 uthread->uu_ar = save_uu_ar;
3593 #endif
3594 if (error != 0) {
3595 goto bad;
3596 }
3597 }
3598
3599 /* Has spawn port actions? */
3600 if (imgp->ip_px_spa != NULL) {
3601 #if CONFIG_AUDIT
3602 /*
3603 * Do the same for the port actions as we did for the file
3604 * actions. Save the AUE_POSIX_SPAWN audit record.
3605 */
3606 struct kaudit_record *save_uu_ar = uthread->uu_ar;
3607 uthread->uu_ar = NULL;
3608 #endif
3609 error = exec_handle_port_actions(imgp, &port_actions);
3610 #if CONFIG_AUDIT
3611 /* Restore the AUE_POSIX_SPAWN audit record. */
3612 uthread->uu_ar = save_uu_ar;
3613 #endif
3614 if (error != 0) {
3615 goto bad;
3616 }
3617 }
3618
3619 /* Has spawn attr? */
3620 if (imgp->ip_px_sa != NULL) {
3621 /*
3622 * Reset UID/GID to parent's RUID/RGID; This works only
3623 * because the operation occurs before the call
3624 * to exec_handle_sugid() by the image activator called
3625 * from exec_activate_image().
3626 *
3627 * POSIX requires that any setuid/setgid bits on the process
3628 * image will take precedence over the spawn attributes
3629 * (re)setting them.
3630 *
3631 * Modifications to p_ucred must be guarded using the
3632 * proc's ucred lock. This prevents others from accessing
3633 * a garbage credential.
3634 */
3635 if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
3636 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred){
3637 return kauth_cred_setuidgid(my_cred,
3638 kauth_cred_getruid(my_cred),
3639 kauth_cred_getrgid(my_cred));
3640 });
3641 }
3642
3643 if (imgp->ip_px_pcred_info) {
3644 if (!spawn_no_exec) {
3645 error = ENOTSUP;
3646 goto bad;
3647 }
3648
3649 error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
3650 if (error != 0) {
3651 goto bad;
3652 }
3653 }
3654
3655 #if CONFIG_PERSONAS
3656 if (imgp->ip_px_persona != NULL) {
3657 if (!spawn_no_exec) {
3658 error = ENOTSUP;
3659 goto bad;
3660 }
3661
3662 /*
3663 * If we were asked to spawn a process into a new persona,
3664 * do the credential switch now (which may override the UID/GID
3665 * inherit done just above). It's important to do this switch
3666 * before image activation both for reasons stated above, and
3667 * to ensure that the new persona has access to the image/file
3668 * being executed.
3669 */
3670 error = spawn_persona_adopt(p, imgp->ip_px_persona);
3671 if (error != 0) {
3672 goto bad;
3673 }
3674 }
3675 #endif /* CONFIG_PERSONAS */
3676 #if !SECURE_KERNEL
3677 /*
3678 * Disable ASLR for the spawned process.
3679 *
3680 * But only do so if we are not embedded + RELEASE.
3681 * While embedded allows for a boot-arg (-disable_aslr)
3682 * to deal with this (which itself is only honored on
3683 * DEVELOPMENT or DEBUG builds of xnu), it is often
3684 * useful or necessary to disable ASLR on a per-process
3685 * basis for unit testing and debugging.
3686 */
3687 if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
3688 OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
3689 }
3690 #endif /* !SECURE_KERNEL */
3691
3692 /* Randomize high bits of ASLR slide */
3693 if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
3694 imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
3695 }
3696
3697 #if !SECURE_KERNEL
3698 /*
3699 * Forcibly disallow execution from data pages for the spawned process
3700 * even if it would otherwise be permitted by the architecture default.
3701 */
3702 if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
3703 imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
3704 }
3705 #endif /* !SECURE_KERNEL */
3706
3707 #if __has_feature(ptrauth_calls)
3708 if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
3709 imgp->ip_flags |= IMGPF_RESLIDE;
3710 }
3711 #endif /* __has_feature(ptrauth_calls) */
3712
3713 if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
3714 POSIX_SPAWN_PROC_TYPE_DRIVER) {
3715 imgp->ip_flags |= IMGPF_DRIVER;
3716 }
3717 }
3718
3719 /*
3720 * Disable ASLR during image activation. This occurs either if the
3721 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
3722 * P_DISABLE_ASLR was inherited from the parent process.
3723 */
3724 if (p->p_flag & P_DISABLE_ASLR) {
3725 imgp->ip_flags |= IMGPF_DISABLE_ASLR;
3726 }
3727
3728 /*
3729 * Clear transition flag so we won't hang if exec_activate_image() causes
3730 * an automount (and launchd does a proc sysctl to service it).
3731 *
3732 * <rdar://problem/6848672>, <rdar://problem/5959568>.
3733 */
3734 if (spawn_no_exec) {
3735 proc_transend(p, 0);
3736 proc_transit_set = 0;
3737 }
3738
3739 #if MAC_SPAWN /* XXX */
3740 if (uap->mac_p != USER_ADDR_NULL) {
3741 error = mac_execve_enter(uap->mac_p, imgp);
3742 if (error) {
3743 goto bad;
3744 }
3745 }
3746 #endif
3747
3748 /*
3749 * Activate the image
3750 */
3751 error = exec_activate_image(imgp);
3752 #if defined(HAS_APPLE_PAC)
3753 ml_task_set_jop_pid_from_shared_region(new_task);
3754 ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
3755 ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
3756 ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
3757 #endif
3758
3759 if (error == 0 && !spawn_no_exec) {
3760 p = proc_exec_switch_task(p, old_task, new_task, imgp->ip_new_thread, &inherit);
3761 /* proc ref returned */
3762 should_release_proc_ref = TRUE;
3763 }
3764
3765 if (error == 0) {
3766 /* process completed the exec */
3767 exec_done = TRUE;
3768 }
3769
3770 if (!error && imgp->ip_px_sa != NULL) {
3771 thread_t child_thread = imgp->ip_new_thread;
3772 uthread_t child_uthread = get_bsdthread_info(child_thread);
3773
3774 /*
3775 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
3776 * activation, else when image activation fails (before the point of no
3777 * return) would leave the parent process in a modified state.
3778 */
3779 if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
3780 struct setpgid_args spga;
3781 spga.pid = proc_getpid(p);
3782 spga.pgid = px_sa.psa_pgroup;
3783 /*
3784 * Effectively, call setpgid() system call; works
3785 * because there are no pointer arguments.
3786 */
3787 if ((error = setpgid(p, &spga, ival)) != 0) {
3788 goto bad;
3789 }
3790 }
3791
3792 if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
3793 error = setsid_internal(p);
3794 if (error != 0) {
3795 goto bad;
3796 }
3797 }
3798
3799 /*
3800 * If we have a spawn attr, and it contains signal related flags,
3801 * the we need to process them in the "context" of the new child
3802 * process, so we have to process it following image activation,
3803 * prior to making the thread runnable in user space. This is
3804 * necessitated by some signal information being per-thread rather
3805 * than per-process, and we don't have the new allocation in hand
3806 * until after the image is activated.
3807 */
3808
3809 /*
3810 * Mask a list of signals, instead of them being unmasked, if
3811 * they were unmasked in the parent; note that some signals
3812 * are not maskable.
3813 */
3814 if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
3815 child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
3816 }
3817 /*
3818 * Default a list of signals instead of ignoring them, if
3819 * they were ignored in the parent. Note that we pass
3820 * spawn_no_exec to setsigvec() to indicate that we called
3821 * fork1() and therefore do not need to call proc_signalstart()
3822 * internally.
3823 */
3824 if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
3825 vec.sa_handler = SIG_DFL;
3826 vec.sa_tramp = 0;
3827 vec.sa_mask = 0;
3828 vec.sa_flags = 0;
3829 for (sig = 1; sig < NSIG; sig++) {
3830 if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
3831 error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
3832 }
3833 }
3834 }
3835
3836 /*
3837 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
3838 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
3839 * limit.
3840 *
3841 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
3842 */
3843 if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
3844 /*
3845 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
3846 * an entitlement to configure the monitor a certain way seems silly, since
3847 * whomever is turning it on could just as easily choose not to do so.
3848 */
3849 error = proc_set_task_ruse_cpu(p->task,
3850 TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
3851 (uint8_t)px_sa.psa_cpumonitor_percent,
3852 px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
3853 0, TRUE);
3854 }
3855
3856
3857 if (px_pcred_info &&
3858 (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
3859 /*
3860 * setlogin() must happen after setsid()
3861 */
3862 setlogin_internal(p, px_pcred_info->pspci_login);
3863 }
3864 }
3865
3866 bad:
3867
3868 if (error == 0) {
3869 /* reset delay idle sleep status if set */
3870 #if CONFIG_DELAY_IDLE_SLEEP
3871 if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
3872 OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
3873 }
3874 #endif /* CONFIG_DELAY_IDLE_SLEEP */
3875 /* upon successful spawn, re/set the proc control state */
3876 if (imgp->ip_px_sa != NULL) {
3877 switch (px_sa.psa_pcontrol) {
3878 case POSIX_SPAWN_PCONTROL_THROTTLE:
3879 p->p_pcaction = P_PCTHROTTLE;
3880 break;
3881 case POSIX_SPAWN_PCONTROL_SUSPEND:
3882 p->p_pcaction = P_PCSUSP;
3883 break;
3884 case POSIX_SPAWN_PCONTROL_KILL:
3885 p->p_pcaction = P_PCKILL;
3886 break;
3887 case POSIX_SPAWN_PCONTROL_NONE:
3888 default:
3889 p->p_pcaction = 0;
3890 break;
3891 }
3892 ;
3893 }
3894 exec_resettextvp(p, imgp);
3895
3896 #if CONFIG_MEMORYSTATUS
3897 /* Set jetsam priority for DriverKit processes */
3898 if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
3899 px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
3900 }
3901
3902 /* Has jetsam attributes? */
3903 if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
3904 /*
3905 * With 2-level high-water-mark support, POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no
3906 * longer relevant, as background limits are described via the inactive limit slots.
3907 *
3908 * That said, however, if the POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in,
3909 * we attempt to mimic previous behavior by forcing the BG limit data into the
3910 * inactive/non-fatal mode and force the active slots to hold system_wide/fatal mode.
3911 */
3912
3913 if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
3914 memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
3915 (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
3916 TRUE,
3917 -1, TRUE,
3918 px_sa.psa_memlimit_inactive, FALSE);
3919 } else {
3920 memorystatus_update(p, px_sa.psa_priority, 0, FALSE, /* assertion priority */
3921 (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY),
3922 TRUE,
3923 px_sa.psa_memlimit_active,
3924 (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL),
3925 px_sa.psa_memlimit_inactive,
3926 (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL));
3927 }
3928 }
3929
3930 /* Has jetsam relaunch behavior? */
3931 if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
3932 /*
3933 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
3934 * This data would be used by the jetsam subsystem to determine the position and protection
3935 * offered to this process on dirty -> clean transitions.
3936 */
3937 int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
3938 switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
3939 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
3940 relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
3941 break;
3942 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
3943 relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
3944 break;
3945 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
3946 relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
3947 break;
3948 default:
3949 break;
3950 }
3951 memorystatus_relaunch_flags_update(p, relaunch_flags);
3952 }
3953
3954 #endif /* CONFIG_MEMORYSTATUS */
3955 if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
3956 task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
3957 }
3958
3959 #if CONFIG_PROC_RESOURCE_LIMITS
3960 if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
3961 task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
3962 (uint32_t)px_sa.psa_port_hard_limit);
3963 }
3964
3965 if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
3966 proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
3967 (int)px_sa.psa_filedesc_hard_limit);
3968 }
3969 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
3970
3971 /* Disable wakeup monitoring for DriverKit processes */
3972 if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
3973 uint32_t flags = WAKEMON_DISABLE;
3974 task_wakeups_monitor_ctl(new_task, &flags, NULL);
3975 }
3976 }
3977
3978 /*
3979 * If we successfully called fork1(), we always need to do this;
3980 * we identify this case by noting the IMGPF_SPAWN flag. This is
3981 * because we come back from that call with signals blocked in the
3982 * child, and we have to unblock them, but we want to wait until
3983 * after we've performed any spawn actions. This has to happen
3984 * before check_for_signature(), which uses psignal.
3985 */
3986 if (spawn_no_exec) {
3987 if (proc_transit_set) {
3988 proc_transend(p, 0);
3989 }
3990
3991 /*
3992 * Drop the signal lock on the child which was taken on our
3993 * behalf by forkproc()/cloneproc() to prevent signals being
3994 * received by the child in a partially constructed state.
3995 */
3996 proc_signalend(p, 0);
3997 }
3998
3999 if (error == 0) {
4000 /*
4001 * We need to initialize the bank context behind the protection of
4002 * the proc_trans lock to prevent a race with exit. We can't do this during
4003 * exec_activate_image because task_bank_init checks entitlements that
4004 * aren't loaded until subsequent calls (including exec_resettextvp).
4005 */
4006 error = proc_transstart(p, 0, 0);
4007
4008 if (error == 0) {
4009 task_bank_init(new_task);
4010 proc_transend(p, 0);
4011 }
4012
4013 #if __arm64__
4014 proc_footprint_entitlement_hacks(p, new_task);
4015 #endif /* __arm64__ */
4016
4017 #if XNU_TARGET_OS_OSX
4018 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4019 if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4020 vm_map_single_jit(get_task_map(new_task));
4021 }
4022 #endif /* XNU_TARGET_OS_OSX */
4023
4024 #if __has_feature(ptrauth_calls)
4025 task_set_pac_exception_fatal_flag(new_task);
4026 #endif /* __has_feature(ptrauth_calls) */
4027 }
4028
4029 /* Inherit task role from old task to new task for exec */
4030 if (error == 0 && !spawn_no_exec) {
4031 proc_inherit_task_role(new_task, old_task);
4032 }
4033
4034 #if CONFIG_ARCADE
4035 if (error == 0) {
4036 /*
4037 * Check to see if we need to trigger an arcade upcall AST now
4038 * that the vnode has been reset on the task.
4039 */
4040 arcade_prepare(new_task, imgp->ip_new_thread);
4041 }
4042 #endif /* CONFIG_ARCADE */
4043
4044 /* Clear the initial wait on the thread before handling spawn policy */
4045 if (imgp && imgp->ip_new_thread) {
4046 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4047 }
4048
4049 /*
4050 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4051 * and bind any portwatch ports to the new task.
4052 * This must be done after the exec so that the child's thread is ready,
4053 * and after the in transit state has been released, because priority is
4054 * dropped here so we need to be prepared for a potentially long preemption interval
4055 *
4056 * TODO: Consider splitting this up into separate phases
4057 */
4058 if (error == 0 && imgp->ip_px_sa != NULL) {
4059 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4060
4061 error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4062 psa->psa_darwin_role, &port_actions);
4063 }
4064
4065 /* Transfer the turnstile watchport boost to new task if in exec */
4066 if (error == 0 && !spawn_no_exec) {
4067 task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4068 }
4069
4070 /*
4071 * Apply the requested maximum address.
4072 */
4073 if (error == 0 && imgp->ip_px_sa != NULL) {
4074 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4075
4076 if (psa->psa_max_addr) {
4077 vm_map_set_max_addr(get_task_map(new_task), (vm_map_offset_t)psa->psa_max_addr);
4078 }
4079 }
4080
4081 if (error == 0 && imgp->ip_px_sa != NULL) {
4082 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4083
4084 if (psa->psa_no_smt) {
4085 task_set_no_smt(new_task);
4086 }
4087 if (psa->psa_tecs) {
4088 task_set_tecs(new_task);
4089 }
4090 }
4091
4092 if (error == 0) {
4093 /* Apply the main thread qos */
4094 thread_t main_thread = imgp->ip_new_thread;
4095 task_set_main_thread_qos(new_task, main_thread);
4096
4097 #if CONFIG_MACF
4098 proc_apply_jit_and_jumbo_va_policies(p, new_task);
4099 #endif /* CONFIG_MACF */
4100 }
4101
4102 /*
4103 * Release any ports we kept around for binding to the new task
4104 * We need to release the rights even if the posix_spawn has failed.
4105 */
4106 if (imgp->ip_px_spa != NULL) {
4107 exec_port_actions_destroy(&port_actions);
4108 }
4109
4110 /*
4111 * We have to delay operations which might throw a signal until after
4112 * the signals have been unblocked; however, we want that to happen
4113 * after exec_resettextvp() so that the textvp is correct when they
4114 * fire.
4115 */
4116 if (error == 0) {
4117 error = check_for_signature(p, imgp);
4118
4119 /*
4120 * Pay for our earlier safety; deliver the delayed signals from
4121 * the incomplete spawn process now that it's complete.
4122 */
4123 if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4124 psignal_vfork(p, p->task, imgp->ip_new_thread, SIGTRAP);
4125 }
4126
4127 if (error == 0 && !spawn_no_exec) {
4128 KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4129 proc_getpid(p));
4130 }
4131 }
4132
4133 if (spawn_no_exec) {
4134 /* flag the 'fork' has occurred */
4135 proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4136 }
4137
4138 /* flag exec has occurred, notify only if it has not failed due to FP Key error */
4139 if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4140 proc_knote(p, NOTE_EXEC);
4141 }
4142
4143 if (imgp != NULL) {
4144 if (imgp->ip_vp) {
4145 vnode_put(imgp->ip_vp);
4146 }
4147 if (imgp->ip_scriptvp) {
4148 vnode_put(imgp->ip_scriptvp);
4149 }
4150 if (imgp->ip_strings) {
4151 execargs_free(imgp);
4152 }
4153 kfree_data(imgp->ip_px_sfa,
4154 px_args.file_actions_size);
4155 kfree_data(imgp->ip_px_spa,
4156 px_args.port_actions_size);
4157 #if CONFIG_PERSONAS
4158 kfree_data(imgp->ip_px_persona,
4159 px_args.persona_info_size);
4160 #endif
4161 kfree_data(imgp->ip_px_pcred_info,
4162 px_args.posix_cred_info_size);
4163
4164 if (subsystem_root_path != NULL) {
4165 zfree(ZV_NAMEI, subsystem_root_path);
4166 }
4167 #if CONFIG_MACF
4168 struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
4169 kfree_data(px_s->array, px_args.mac_extensions_size);
4170 kfree_data(px_s->data, (vm_size_t)px_s->datalen);
4171
4172 if (imgp->ip_execlabelp) {
4173 mac_cred_label_free(imgp->ip_execlabelp);
4174 imgp->ip_execlabelp = NULL;
4175 }
4176 if (imgp->ip_scriptlabelp) {
4177 mac_vnode_label_free(imgp->ip_scriptlabelp);
4178 imgp->ip_scriptlabelp = NULL;
4179 }
4180 if (imgp->ip_cs_error != OS_REASON_NULL) {
4181 os_reason_free(imgp->ip_cs_error);
4182 imgp->ip_cs_error = OS_REASON_NULL;
4183 }
4184 if (imgp->ip_inherited_shared_region_id != NULL) {
4185 kfree_data(imgp->ip_inherited_shared_region_id,
4186 strlen(imgp->ip_inherited_shared_region_id) + 1);
4187 imgp->ip_inherited_shared_region_id = NULL;
4188 }
4189 #endif
4190 if (imgp->ip_sc_port != NULL) {
4191 ipc_port_release_send(imgp->ip_sc_port);
4192 imgp->ip_sc_port = NULL;
4193 }
4194 }
4195
4196 #if CONFIG_DTRACE
4197 if (spawn_no_exec) {
4198 /*
4199 * In the original DTrace reference implementation,
4200 * posix_spawn() was a libc routine that just
4201 * did vfork(2) then exec(2). Thus the proc::: probes
4202 * are very fork/exec oriented. The details of this
4203 * in-kernel implementation of posix_spawn() is different
4204 * (while producing the same process-observable effects)
4205 * particularly w.r.t. errors, and which thread/process
4206 * is constructing what on behalf of whom.
4207 */
4208 if (error) {
4209 DTRACE_PROC1(spawn__failure, int, error);
4210 } else {
4211 DTRACE_PROC(spawn__success);
4212 /*
4213 * Some DTrace scripts, e.g. newproc.d in
4214 * /usr/bin, rely on the the 'exec-success'
4215 * probe being fired in the child after the
4216 * new process image has been constructed
4217 * in order to determine the associated pid.
4218 *
4219 * So, even though the parent built the image
4220 * here, for compatibility, mark the new thread
4221 * so 'exec-success' fires on it as it leaves
4222 * the kernel.
4223 */
4224 dtrace_thread_didexec(imgp->ip_new_thread);
4225 }
4226 } else {
4227 if (error) {
4228 DTRACE_PROC1(exec__failure, int, error);
4229 } else {
4230 dtrace_thread_didexec(imgp->ip_new_thread);
4231 }
4232 }
4233
4234 if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4235 (*dtrace_proc_waitfor_hook)(p);
4236 }
4237 #endif
4238
4239 #if CONFIG_AUDIT
4240 if (!error && AUDIT_ENABLED() && p) {
4241 /* Add the CDHash of the new process to the audit record */
4242 uint8_t *cdhash = cs_get_cdhash(p);
4243 if (cdhash) {
4244 AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4245 }
4246 }
4247 #endif
4248
4249 /*
4250 * clear bsd_info from old task if it did exec.
4251 */
4252 if (task_did_exec(old_task)) {
4253 set_bsdtask_info(old_task, NULL);
4254 clear_thread_ro_proc(get_machthread(uthread));
4255 }
4256
4257 /* clear bsd_info from new task and terminate it if exec failed */
4258 if (new_task != NULL && task_is_exec_copy(new_task)) {
4259 set_bsdtask_info(new_task, NULL);
4260 task_terminate_internal(new_task);
4261 if (imgp && imgp->ip_new_thread) {
4262 clear_thread_ro_proc(imgp->ip_new_thread);
4263 }
4264 }
4265
4266 /* Return to both the parent and the child? */
4267 if (imgp != NULL && spawn_no_exec) {
4268 /*
4269 * If the parent wants the pid, copy it out
4270 */
4271 if (pid != USER_ADDR_NULL) {
4272 _Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
4273 bool aligned = (pid & 3) == 0;
4274 if (aligned) {
4275 (void)copyout_atomic32(proc_getpid(p), pid);
4276 } else {
4277 (void)suword(pid, proc_getpid(p));
4278 }
4279 }
4280 retval[0] = error;
4281
4282 /*
4283 * If we had an error, perform an internal reap ; this is
4284 * entirely safe, as we have a real process backing us.
4285 */
4286 if (error) {
4287 proc_list_lock();
4288 p->p_listflag |= P_LIST_DEADPARENT;
4289 proc_list_unlock();
4290 proc_lock(p);
4291 /* make sure no one else has killed it off... */
4292 if (p->p_stat != SZOMB && p->exit_thread == NULL) {
4293 p->exit_thread = current_thread();
4294 proc_unlock(p);
4295 exit1(p, 1, (int *)NULL);
4296 } else {
4297 /* someone is doing it for us; just skip it */
4298 proc_unlock(p);
4299 }
4300 }
4301 }
4302
4303 /*
4304 * Do not terminate the current task, if proc_exec_switch_task did not
4305 * switch the tasks, terminating the current task without the switch would
4306 * result in loosing the SIGKILL status.
4307 */
4308 if (task_did_exec(old_task)) {
4309 /* Terminate the current task, since exec will start in new task */
4310 task_terminate_internal(old_task);
4311 }
4312
4313 /* Release the thread ref returned by fork_create_child/fork1 */
4314 if (imgp != NULL && imgp->ip_new_thread) {
4315 /* wake up the new thread */
4316 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4317 thread_deallocate(imgp->ip_new_thread);
4318 imgp->ip_new_thread = NULL;
4319 }
4320
4321 /* Release the ref returned by fork_create_child/fork1 */
4322 if (new_task) {
4323 task_deallocate(new_task);
4324 new_task = NULL;
4325 }
4326
4327 if (should_release_proc_ref) {
4328 proc_rele(p);
4329 }
4330
4331 kfree_type(typeof(*__spawn_data), __spawn_data);
4332
4333 if (inherit != NULL) {
4334 ipc_importance_release(inherit);
4335 }
4336
4337 return error;
4338 }
4339
4340 /*
4341 * proc_exec_switch_task
4342 *
4343 * Parameters: p proc
4344 * old_task task before exec
4345 * new_task task after exec
4346 * new_thread thread in new task
4347 * inherit resulting importance linkage
4348 *
4349 * Returns: proc.
4350 *
4351 * Note: The function will switch the task pointer of proc
4352 * from old task to new task. The switch needs to happen
4353 * after draining all proc refs and inside a proc translock.
4354 * In the case of failure to switch the task, which might happen
4355 * if the process received a SIGKILL or jetsam killed it, it will make
4356 * sure that the new tasks terminates. User proc ref returned
4357 * to caller.
4358 *
4359 * This function is called after point of no return, in the case
4360 * failure to switch, it will terminate the new task and swallow the
4361 * error and let the terminated process complete exec and die.
4362 */
4363 proc_t
proc_exec_switch_task(proc_t p,task_t old_task,task_t new_task,thread_t new_thread,void ** inherit)4364 proc_exec_switch_task(proc_t p, task_t old_task, task_t new_task, thread_t new_thread,
4365 void **inherit)
4366 {
4367 int error = 0;
4368 boolean_t task_active;
4369 boolean_t proc_active;
4370 boolean_t thread_active;
4371 thread_t old_thread = current_thread();
4372
4373 /*
4374 * Switch the task pointer of proc to new task.
4375 * Before switching the task, wait for proc_refdrain.
4376 * After the switch happens, the proc can disappear,
4377 * take a ref before it disappears. Waiting for
4378 * proc_refdrain in exec will block all other threads
4379 * trying to take a proc ref, boost the current thread
4380 * to avoid priority inversion.
4381 */
4382 thread_set_exec_promotion(old_thread);
4383 p = proc_refdrain_will_exec(p);
4384 /* extra proc ref returned to the caller */
4385
4386 assert(get_threadtask(new_thread) == new_task);
4387 task_active = task_is_active(new_task);
4388
4389 /* Take the proc_translock to change the task ptr */
4390 proc_lock(p);
4391 proc_active = !(p->p_lflag & P_LEXIT);
4392
4393 /* Check if the current thread is not aborted due to SIGKILL */
4394 thread_active = thread_is_active(old_thread);
4395
4396 /*
4397 * Do not switch the task if the new task or proc is already terminated
4398 * as a result of error in exec past point of no return
4399 */
4400 if (proc_active && task_active && thread_active) {
4401 error = proc_transstart(p, 1, 0);
4402 if (error == 0) {
4403 uthread_t new_uthread = get_bsdthread_info(new_thread);
4404 uthread_t old_uthread = current_uthread();
4405
4406 /*
4407 * bsd_info of old_task will get cleared in execve and posix_spawn
4408 * after firing exec-success/error dtrace probe.
4409 */
4410 proc_set_task(p, new_task);
4411 proc_switch_ro(p, task_get_ro(new_task));
4412
4413 /* Clear dispatchqueue and workloop ast offset */
4414 p->p_dispatchqueue_offset = 0;
4415 p->p_dispatchqueue_serialno_offset = 0;
4416 p->p_dispatchqueue_label_offset = 0;
4417 p->p_return_to_kernel_offset = 0;
4418 p->p_pthread_wq_quantum_offset = 0;
4419
4420 /* Copy the signal state, dtrace state and set bsd ast on new thread */
4421 act_set_astbsd(new_thread);
4422 new_uthread->uu_siglist = old_uthread->uu_siglist;
4423 new_uthread->uu_sigwait = old_uthread->uu_sigwait;
4424 new_uthread->uu_sigmask = old_uthread->uu_sigmask;
4425 new_uthread->uu_oldmask = old_uthread->uu_oldmask;
4426 new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
4427 #if CONFIG_DTRACE
4428 new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
4429 new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
4430 new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
4431 assert(new_uthread->t_dtrace_scratch == NULL);
4432 new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
4433
4434 old_uthread->t_dtrace_sig = 0;
4435 old_uthread->t_dtrace_stop = 0;
4436 old_uthread->t_dtrace_resumepid = 0;
4437 old_uthread->t_dtrace_scratch = NULL;
4438 #endif
4439 /* Copy the resource accounting info */
4440 thread_copy_resource_info(new_thread, current_thread());
4441
4442 /* Clear the exit reason and signal state on old thread */
4443 old_uthread->uu_exit_reason = NULL;
4444 old_uthread->uu_siglist = 0;
4445
4446 /* Add the new uthread to proc uthlist and remove the old one */
4447 TAILQ_REMOVE(&p->p_uthlist, old_uthread, uu_list);
4448 assert(TAILQ_EMPTY(&p->p_uthlist));
4449 TAILQ_INSERT_TAIL(&p->p_uthlist, new_uthread, uu_list);
4450
4451 task_set_did_exec_flag(old_task);
4452 task_clear_exec_copy_flag(new_task);
4453
4454 task_copy_fields_for_exec(new_task, old_task);
4455
4456 /* Transfer sandbox filter bits to new_task. */
4457 task_transfer_mach_filter_bits(new_task, old_task);
4458
4459 /*
4460 * Need to transfer pending watch port boosts to the new task
4461 * while still making sure that the old task remains in the
4462 * importance linkage. Create an importance linkage from old task
4463 * to new task, then switch the task importance base of old task
4464 * and new task. After the switch the port watch boost will be
4465 * boosting the new task and new task will be donating importance
4466 * to old task.
4467 */
4468 *inherit = ipc_importance_exec_switch_task(old_task, new_task);
4469
4470 proc_transend(p, 1);
4471 }
4472 }
4473
4474 proc_unlock(p);
4475 proc_refwake_did_exec(p);
4476 thread_clear_exec_promotion(old_thread);
4477
4478 if (error != 0 || !task_active || !proc_active || !thread_active) {
4479 task_terminate_internal(new_task);
4480 }
4481
4482 return p;
4483 }
4484
4485 /*
4486 * execve
4487 *
4488 * Parameters: uap->fname File name to exec
4489 * uap->argp Argument list
4490 * uap->envp Environment list
4491 *
4492 * Returns: 0 Success
4493 * __mac_execve:EINVAL Invalid argument
4494 * __mac_execve:ENOTSUP Invalid argument
4495 * __mac_execve:EACCES Permission denied
4496 * __mac_execve:EINTR Interrupted function
4497 * __mac_execve:ENOMEM Not enough space
4498 * __mac_execve:EFAULT Bad address
4499 * __mac_execve:ENAMETOOLONG Filename too long
4500 * __mac_execve:ENOEXEC Executable file format error
4501 * __mac_execve:ETXTBSY Text file busy [misuse of error code]
4502 * __mac_execve:???
4503 *
4504 * TODO: Dynamic linker header address on stack is copied via suword()
4505 */
4506 /* ARGSUSED */
4507 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)4508 execve(proc_t p, struct execve_args *uap, int32_t *retval)
4509 {
4510 struct __mac_execve_args muap;
4511 int err;
4512
4513 memoryshot(VM_EXECVE, DBG_FUNC_NONE);
4514
4515 muap.fname = uap->fname;
4516 muap.argp = uap->argp;
4517 muap.envp = uap->envp;
4518 muap.mac_p = USER_ADDR_NULL;
4519 err = __mac_execve(p, &muap, retval);
4520
4521 return err;
4522 }
4523
4524 /*
4525 * __mac_execve
4526 *
4527 * Parameters: uap->fname File name to exec
4528 * uap->argp Argument list
4529 * uap->envp Environment list
4530 * uap->mac_p MAC label supplied by caller
4531 *
4532 * Returns: 0 Success
4533 * EINVAL Invalid argument
4534 * ENOTSUP Not supported
4535 * ENOEXEC Executable file format error
4536 * exec_activate_image:EINVAL Invalid argument
4537 * exec_activate_image:EACCES Permission denied
4538 * exec_activate_image:EINTR Interrupted function
4539 * exec_activate_image:ENOMEM Not enough space
4540 * exec_activate_image:EFAULT Bad address
4541 * exec_activate_image:ENAMETOOLONG Filename too long
4542 * exec_activate_image:ENOEXEC Executable file format error
4543 * exec_activate_image:ETXTBSY Text file busy [misuse of error code]
4544 * exec_activate_image:EBADEXEC The executable is corrupt/unknown
4545 * exec_activate_image:???
4546 * mac_execve_enter:???
4547 *
4548 * TODO: Dynamic linker header address on stack is copied via suword()
4549 */
4550 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)4551 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
4552 {
4553 struct image_params *imgp = NULL;
4554 struct vnode_attr *vap = NULL;
4555 struct vnode_attr *origvap = NULL;
4556 int error;
4557 int is_64 = IS_64BIT_PROCESS(p);
4558 struct vfs_context context;
4559 struct uthread *uthread = NULL;
4560 task_t old_task = current_task();
4561 task_t new_task = NULL;
4562 boolean_t should_release_proc_ref = FALSE;
4563 boolean_t exec_done = FALSE;
4564 const bool in_vfexec = false;
4565 void *inherit = NULL;
4566 struct {
4567 struct image_params imgp;
4568 struct vnode_attr va;
4569 struct vnode_attr origva;
4570 } *__execve_data;
4571
4572 context.vc_thread = current_thread();
4573 context.vc_ucred = kauth_cred_proc_ref(p); /* XXX must NOT be kauth_cred_get() */
4574
4575 /* Allocate a big chunk for locals instead of using stack since these
4576 * structures a pretty big.
4577 */
4578 __execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
4579 if (__execve_data == NULL) {
4580 error = ENOMEM;
4581 goto exit_with_error;
4582 }
4583 imgp = &__execve_data->imgp;
4584 vap = &__execve_data->va;
4585 origvap = &__execve_data->origva;
4586
4587 /* Initialize the common data in the image_params structure */
4588 imgp->ip_user_fname = uap->fname;
4589 imgp->ip_user_argv = uap->argp;
4590 imgp->ip_user_envv = uap->envp;
4591 imgp->ip_vattr = vap;
4592 imgp->ip_origvattr = origvap;
4593 imgp->ip_vfs_context = &context;
4594 imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
4595 imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
4596 imgp->ip_mac_return = 0;
4597 imgp->ip_cs_error = OS_REASON_NULL;
4598 imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
4599 imgp->ip_subsystem_root_path = NULL;
4600
4601 #if CONFIG_MACF
4602 if (uap->mac_p != USER_ADDR_NULL) {
4603 error = mac_execve_enter(uap->mac_p, imgp);
4604 if (error) {
4605 kauth_cred_unref(&context.vc_ucred);
4606 goto exit_with_error;
4607 }
4608 }
4609 #endif
4610 uthread = current_uthread();
4611 {
4612 imgp->ip_flags |= IMGPF_EXEC;
4613
4614 /*
4615 * For execve case, create a new task and thread
4616 * which points to current_proc. The current_proc will point
4617 * to the new task after image activation and proc ref drain.
4618 *
4619 * proc (current_proc) <----- old_task (current_task)
4620 * ^ | ^
4621 * | | |
4622 * | ----------------------------------
4623 * |
4624 * --------- new_task (task marked as TF_EXEC_COPY)
4625 *
4626 * After image activation, the proc will point to the new task
4627 * and would look like following.
4628 *
4629 * proc (current_proc) <----- old_task (current_task, marked as TPF_DID_EXEC)
4630 * ^ |
4631 * | |
4632 * | ----------> new_task
4633 * | |
4634 * -----------------
4635 *
4636 * During exec any transition from new_task -> proc is fine, but don't allow
4637 * transition from proc->task, since it will modify old_task.
4638 */
4639 imgp->ip_new_thread = fork_create_child(old_task,
4640 NULL,
4641 p,
4642 FALSE,
4643 p->p_flag & P_LP64,
4644 task_get_64bit_data(old_task),
4645 TRUE);
4646 /* task and thread ref returned by fork_create_child */
4647 if (imgp->ip_new_thread == NULL) {
4648 error = ENOMEM;
4649 goto exit_with_error;
4650 }
4651
4652 new_task = get_threadtask(imgp->ip_new_thread);
4653 context.vc_thread = imgp->ip_new_thread;
4654 }
4655
4656 imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4657
4658 error = exec_activate_image(imgp);
4659 /* thread and task ref returned for vfexec case */
4660
4661 if (imgp->ip_new_thread != NULL) {
4662 /*
4663 * task reference might be returned by exec_activate_image
4664 * for vfexec.
4665 */
4666 new_task = get_threadtask(imgp->ip_new_thread);
4667 #if defined(HAS_APPLE_PAC)
4668 ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
4669 ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
4670 #endif
4671 }
4672
4673 if (!error && !in_vfexec) {
4674 p = proc_exec_switch_task(p, old_task, new_task, imgp->ip_new_thread, &inherit);
4675 /* proc ref returned */
4676 should_release_proc_ref = TRUE;
4677 }
4678
4679 kauth_cred_unref(&context.vc_ucred);
4680
4681 if (!error) {
4682 exec_done = TRUE;
4683 assert(imgp->ip_new_thread != NULL);
4684
4685 exec_resettextvp(p, imgp);
4686 error = check_for_signature(p, imgp);
4687 }
4688
4689 #if defined(HAS_APPLE_PAC)
4690 if (imgp->ip_new_thread && !error) {
4691 ml_task_set_jop_pid_from_shared_region(new_task);
4692 ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4693 }
4694 #endif /* defined(HAS_APPLE_PAC) */
4695
4696 /* flag exec has occurred, notify only if it has not failed due to FP Key error */
4697 if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4698 proc_knote(p, NOTE_EXEC);
4699 }
4700
4701 if (imgp->ip_vp != NULLVP) {
4702 vnode_put(imgp->ip_vp);
4703 }
4704 if (imgp->ip_scriptvp != NULLVP) {
4705 vnode_put(imgp->ip_scriptvp);
4706 }
4707 if (imgp->ip_strings) {
4708 execargs_free(imgp);
4709 }
4710 #if CONFIG_MACF
4711 if (imgp->ip_execlabelp) {
4712 mac_cred_label_free(imgp->ip_execlabelp);
4713 imgp->ip_execlabelp = NULL;
4714 }
4715 if (imgp->ip_scriptlabelp) {
4716 mac_vnode_label_free(imgp->ip_scriptlabelp);
4717 imgp->ip_scriptlabelp = NULL;
4718 }
4719 #endif
4720 if (imgp->ip_cs_error != OS_REASON_NULL) {
4721 os_reason_free(imgp->ip_cs_error);
4722 imgp->ip_cs_error = OS_REASON_NULL;
4723 }
4724
4725 if (!error) {
4726 /*
4727 * We need to initialize the bank context behind the protection of
4728 * the proc_trans lock to prevent a race with exit. We can't do this during
4729 * exec_activate_image because task_bank_init checks entitlements that
4730 * aren't loaded until subsequent calls (including exec_resettextvp).
4731 */
4732 error = proc_transstart(p, 0, 0);
4733 }
4734
4735 if (!error) {
4736 task_bank_init(new_task);
4737 proc_transend(p, 0);
4738
4739 #if __arm64__
4740 proc_footprint_entitlement_hacks(p, new_task);
4741 #endif /* __arm64__ */
4742
4743 #if XNU_TARGET_OS_OSX
4744 if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4745 vm_map_single_jit(get_task_map(new_task));
4746 }
4747 #endif /* XNU_TARGET_OS_OSX */
4748
4749 /* Sever any extant thread affinity */
4750 thread_affinity_exec(current_thread());
4751
4752 /* Inherit task role from old task to new task for exec */
4753 if (!in_vfexec) {
4754 proc_inherit_task_role(new_task, old_task);
4755 }
4756
4757 thread_t main_thread = imgp->ip_new_thread;
4758
4759 task_set_main_thread_qos(new_task, main_thread);
4760
4761 #if __has_feature(ptrauth_calls)
4762 task_set_pac_exception_fatal_flag(new_task);
4763 #endif /* __has_feature(ptrauth_calls) */
4764
4765 #if CONFIG_ARCADE
4766 /*
4767 * Check to see if we need to trigger an arcade upcall AST now
4768 * that the vnode has been reset on the task.
4769 */
4770 arcade_prepare(new_task, imgp->ip_new_thread);
4771 #endif /* CONFIG_ARCADE */
4772
4773 #if CONFIG_MACF
4774 proc_apply_jit_and_jumbo_va_policies(p, new_task);
4775 #endif /* CONFIG_MACF */
4776
4777 if (vm_darkwake_mode == TRUE) {
4778 /*
4779 * This process is being launched when the system
4780 * is in darkwake. So mark it specially. This will
4781 * cause all its pages to be entered in the background Q.
4782 */
4783 task_set_darkwake_mode(new_task, vm_darkwake_mode);
4784 }
4785
4786 #if CONFIG_DTRACE
4787 dtrace_thread_didexec(imgp->ip_new_thread);
4788
4789 if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4790 (*dtrace_proc_waitfor_hook)(p);
4791 }
4792 #endif
4793
4794 #if CONFIG_AUDIT
4795 if (!error && AUDIT_ENABLED() && p) {
4796 /* Add the CDHash of the new process to the audit record */
4797 uint8_t *cdhash = cs_get_cdhash(p);
4798 if (cdhash) {
4799 AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4800 }
4801 }
4802 #endif
4803 } else {
4804 DTRACE_PROC1(exec__failure, int, error);
4805 }
4806
4807 exit_with_error:
4808
4809 /*
4810 * clear bsd_info from old task if it did exec.
4811 */
4812 if (task_did_exec(old_task)) {
4813 set_bsdtask_info(old_task, NULL);
4814 clear_thread_ro_proc(get_machthread(uthread));
4815 }
4816
4817 /* clear bsd_info from new task and terminate it if exec failed */
4818 if (new_task != NULL && task_is_exec_copy(new_task)) {
4819 set_bsdtask_info(new_task, NULL);
4820 if (imgp && imgp->ip_new_thread) {
4821 clear_thread_ro_proc(imgp->ip_new_thread);
4822 }
4823 task_terminate_internal(new_task);
4824 }
4825
4826 if (imgp != NULL) {
4827 /* Clear the initial wait on the thread transferring watchports */
4828 if (imgp->ip_new_thread) {
4829 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4830 }
4831
4832 /* Transfer the watchport boost to new task */
4833 if (!error && !in_vfexec) {
4834 task_transfer_turnstile_watchports(old_task,
4835 new_task, imgp->ip_new_thread);
4836 }
4837 /*
4838 * Do not terminate the current task, if proc_exec_switch_task did not
4839 * switch the tasks, terminating the current task without the switch would
4840 * result in loosing the SIGKILL status.
4841 */
4842 if (task_did_exec(old_task)) {
4843 /* Terminate the current task, since exec will start in new task */
4844 task_terminate_internal(old_task);
4845 }
4846
4847 /* Release the thread ref returned by fork_create_child */
4848 if (imgp->ip_new_thread) {
4849 /* wake up the new exec thread */
4850 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4851 thread_deallocate(imgp->ip_new_thread);
4852 imgp->ip_new_thread = NULL;
4853 }
4854 }
4855
4856 /* Release the ref returned by fork_create_child */
4857 if (new_task) {
4858 task_deallocate(new_task);
4859 new_task = NULL;
4860 }
4861
4862 if (should_release_proc_ref) {
4863 proc_rele(p);
4864 }
4865
4866 kfree_type(typeof(*__execve_data), __execve_data);
4867
4868 if (inherit != NULL) {
4869 ipc_importance_release(inherit);
4870 }
4871
4872 return error;
4873 }
4874
4875
4876 /*
4877 * copyinptr
4878 *
4879 * Description: Copy a pointer in from user space to a user_addr_t in kernel
4880 * space, based on 32/64 bitness of the user space
4881 *
4882 * Parameters: froma User space address
4883 * toptr Address of kernel space user_addr_t
4884 * ptr_size 4/8, based on 'froma' address space
4885 *
4886 * Returns: 0 Success
4887 * EFAULT Bad 'froma'
4888 *
4889 * Implicit returns:
4890 * *ptr_size Modified
4891 */
4892 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)4893 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
4894 {
4895 int error;
4896
4897 if (ptr_size == 4) {
4898 /* 64 bit value containing 32 bit address */
4899 unsigned int i = 0;
4900
4901 error = copyin(froma, &i, 4);
4902 *toptr = CAST_USER_ADDR_T(i); /* SAFE */
4903 } else {
4904 error = copyin(froma, toptr, 8);
4905 }
4906 return error;
4907 }
4908
4909
4910 /*
4911 * copyoutptr
4912 *
4913 * Description: Copy a pointer out from a user_addr_t in kernel space to
4914 * user space, based on 32/64 bitness of the user space
4915 *
4916 * Parameters: ua User space address to copy to
4917 * ptr Address of kernel space user_addr_t
4918 * ptr_size 4/8, based on 'ua' address space
4919 *
4920 * Returns: 0 Success
4921 * EFAULT Bad 'ua'
4922 *
4923 */
4924 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)4925 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
4926 {
4927 int error;
4928
4929 if (ptr_size == 4) {
4930 /* 64 bit value containing 32 bit address */
4931 unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua); /* SAFE */
4932
4933 error = copyout(&i, ptr, 4);
4934 } else {
4935 error = copyout(&ua, ptr, 8);
4936 }
4937 return error;
4938 }
4939
4940
4941 /*
4942 * exec_copyout_strings
4943 *
4944 * Copy out the strings segment to user space. The strings segment is put
4945 * on a preinitialized stack frame.
4946 *
4947 * Parameters: struct image_params * the image parameter block
4948 * int * a pointer to the stack offset variable
4949 *
4950 * Returns: 0 Success
4951 * !0 Faiure: errno
4952 *
4953 * Implicit returns:
4954 * (*stackp) The stack offset, modified
4955 *
4956 * Note: The strings segment layout is backward, from the beginning
4957 * of the top of the stack to consume the minimal amount of
4958 * space possible; the returned stack pointer points to the
4959 * end of the area consumed (stacks grow downward).
4960 *
4961 * argc is an int; arg[i] are pointers; env[i] are pointers;
4962 * the 0's are (void *)NULL's
4963 *
4964 * The stack frame layout is:
4965 *
4966 * +-------------+ <- p->user_stack
4967 * | 16b |
4968 * +-------------+
4969 * | STRING AREA |
4970 * | : |
4971 * | : |
4972 * | : |
4973 * +- -- -- -- --+
4974 * | PATH AREA |
4975 * +-------------+
4976 * | 0 |
4977 * +-------------+
4978 * | applev[n] |
4979 * +-------------+
4980 * :
4981 * :
4982 * +-------------+
4983 * | applev[1] |
4984 * +-------------+
4985 * | exec_path / |
4986 * | applev[0] |
4987 * +-------------+
4988 * | 0 |
4989 * +-------------+
4990 * | env[n] |
4991 * +-------------+
4992 * :
4993 * :
4994 * +-------------+
4995 * | env[0] |
4996 * +-------------+
4997 * | 0 |
4998 * +-------------+
4999 * | arg[argc-1] |
5000 * +-------------+
5001 * :
5002 * :
5003 * +-------------+
5004 * | arg[0] |
5005 * +-------------+
5006 * | argc |
5007 * sp-> +-------------+
5008 *
5009 * Although technically a part of the STRING AREA, we treat the PATH AREA as
5010 * a separate entity. This allows us to align the beginning of the PATH AREA
5011 * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
5012 * which preceed it on the stack are properly aligned.
5013 */
5014 __attribute__((noinline))
5015 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)5016 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
5017 {
5018 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5019 int ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5020 int ptr_area_size;
5021 void *ptr_buffer_start, *ptr_buffer;
5022 size_t string_size;
5023
5024 user_addr_t string_area; /* *argv[], *env[] */
5025 user_addr_t ptr_area; /* argv[], env[], applev[] */
5026 user_addr_t argc_area; /* argc */
5027 user_addr_t stack;
5028 int error;
5029
5030 unsigned i;
5031 struct copyout_desc {
5032 char *start_string;
5033 int count;
5034 #if CONFIG_DTRACE
5035 user_addr_t *dtrace_cookie;
5036 #endif
5037 boolean_t null_term;
5038 } descriptors[] = {
5039 {
5040 .start_string = imgp->ip_startargv,
5041 .count = imgp->ip_argc,
5042 #if CONFIG_DTRACE
5043 .dtrace_cookie = &p->p_dtrace_argv,
5044 #endif
5045 .null_term = TRUE
5046 },
5047 {
5048 .start_string = imgp->ip_endargv,
5049 .count = imgp->ip_envc,
5050 #if CONFIG_DTRACE
5051 .dtrace_cookie = &p->p_dtrace_envp,
5052 #endif
5053 .null_term = TRUE
5054 },
5055 {
5056 .start_string = imgp->ip_strings,
5057 .count = 1,
5058 #if CONFIG_DTRACE
5059 .dtrace_cookie = NULL,
5060 #endif
5061 .null_term = FALSE
5062 },
5063 {
5064 .start_string = imgp->ip_endenvv,
5065 .count = imgp->ip_applec - 1, /* exec_path handled above */
5066 #if CONFIG_DTRACE
5067 .dtrace_cookie = NULL,
5068 #endif
5069 .null_term = TRUE
5070 }
5071 };
5072
5073 stack = *stackp;
5074
5075 /*
5076 * All previous contributors to the string area
5077 * should have aligned their sub-area
5078 */
5079 if (imgp->ip_strspace % ptr_size != 0) {
5080 error = EINVAL;
5081 goto bad;
5082 }
5083
5084 /* Grow the stack down for the strings we've been building up */
5085 string_size = imgp->ip_strendp - imgp->ip_strings;
5086 stack -= string_size;
5087 string_area = stack;
5088
5089 /*
5090 * Need room for one pointer for each string, plus
5091 * one for the NULLs terminating the argv, envv, and apple areas.
5092 */
5093 ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5094 stack -= ptr_area_size;
5095 ptr_area = stack;
5096
5097 /* We'll construct all the pointer arrays in our string buffer,
5098 * which we already know is aligned properly, and ip_argspace
5099 * was used to verify we have enough space.
5100 */
5101 ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5102
5103 /*
5104 * Need room for pointer-aligned argc slot.
5105 */
5106 stack -= ptr_size;
5107 argc_area = stack;
5108
5109 /*
5110 * Record the size of the arguments area so that sysctl_procargs()
5111 * can return the argument area without having to parse the arguments.
5112 */
5113 proc_lock(p);
5114 p->p_argc = imgp->ip_argc;
5115 p->p_argslen = (int)(*stackp - string_area);
5116 proc_unlock(p);
5117
5118 /* Return the initial stack address: the location of argc */
5119 *stackp = stack;
5120
5121 /*
5122 * Copy out the entire strings area.
5123 */
5124 error = copyout(imgp->ip_strings, string_area,
5125 string_size);
5126 if (error) {
5127 goto bad;
5128 }
5129
5130 for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
5131 char *cur_string = descriptors[i].start_string;
5132 int j;
5133
5134 #if CONFIG_DTRACE
5135 if (descriptors[i].dtrace_cookie) {
5136 proc_lock(p);
5137 *descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
5138 proc_unlock(p);
5139 }
5140 #endif /* CONFIG_DTRACE */
5141
5142 /*
5143 * For each segment (argv, envv, applev), copy as many pointers as requested
5144 * to our pointer buffer.
5145 */
5146 for (j = 0; j < descriptors[i].count; j++) {
5147 user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
5148
5149 /* Copy out the pointer to the current string. Alignment has been verified */
5150 if (ptr_size == 8) {
5151 *(uint64_t *)ptr_buffer = (uint64_t)cur_address;
5152 } else {
5153 *(uint32_t *)ptr_buffer = (uint32_t)cur_address;
5154 }
5155
5156 ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5157 cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
5158 }
5159
5160 if (descriptors[i].null_term) {
5161 if (ptr_size == 8) {
5162 *(uint64_t *)ptr_buffer = 0ULL;
5163 } else {
5164 *(uint32_t *)ptr_buffer = 0;
5165 }
5166
5167 ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5168 }
5169 }
5170
5171 /*
5172 * Copy out all our pointer arrays in bulk.
5173 */
5174 error = copyout(ptr_buffer_start, ptr_area,
5175 ptr_area_size);
5176 if (error) {
5177 goto bad;
5178 }
5179
5180 /* argc (int32, stored in a ptr_size area) */
5181 error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
5182 if (error) {
5183 goto bad;
5184 }
5185
5186 bad:
5187 return error;
5188 }
5189
5190
5191 /*
5192 * exec_extract_strings
5193 *
5194 * Copy arguments and environment from user space into work area; we may
5195 * have already copied some early arguments into the work area, and if
5196 * so, any arguments opied in are appended to those already there.
5197 * This function is the primary manipulator of ip_argspace, since
5198 * these are the arguments the client of execve(2) knows about. After
5199 * each argv[]/envv[] string is copied, we charge the string length
5200 * and argv[]/envv[] pointer slot to ip_argspace, so that we can
5201 * full preflight the arg list size.
5202 *
5203 * Parameters: struct image_params * the image parameter block
5204 *
5205 * Returns: 0 Success
5206 * !0 Failure: errno
5207 *
5208 * Implicit returns;
5209 * (imgp->ip_argc) Count of arguments, updated
5210 * (imgp->ip_envc) Count of environment strings, updated
5211 * (imgp->ip_argspace) Count of remaining of NCARGS
5212 * (imgp->ip_interp_buffer) Interpreter and args (mutated in place)
5213 *
5214 *
5215 * Note: The argument and environment vectors are user space pointers
5216 * to arrays of user space pointers.
5217 */
5218 __attribute__((noinline))
5219 static int
exec_extract_strings(struct image_params * imgp)5220 exec_extract_strings(struct image_params *imgp)
5221 {
5222 int error = 0;
5223 int ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
5224 int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5225 user_addr_t argv = imgp->ip_user_argv;
5226 user_addr_t envv = imgp->ip_user_envv;
5227
5228 /*
5229 * Adjust space reserved for the path name by however much padding it
5230 * needs. Doing this here since we didn't know if this would be a 32-
5231 * or 64-bit process back in exec_save_path.
5232 */
5233 while (imgp->ip_strspace % new_ptr_size != 0) {
5234 *imgp->ip_strendp++ = '\0';
5235 imgp->ip_strspace--;
5236 /* imgp->ip_argspace--; not counted towards exec args total */
5237 }
5238
5239 /*
5240 * From now on, we start attributing string space to ip_argspace
5241 */
5242 imgp->ip_startargv = imgp->ip_strendp;
5243 imgp->ip_argc = 0;
5244
5245 if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
5246 user_addr_t arg;
5247 char *argstart, *ch;
5248
5249 /* First, the arguments in the "#!" string are tokenized and extracted. */
5250 argstart = imgp->ip_interp_buffer;
5251 while (argstart) {
5252 ch = argstart;
5253 while (*ch && !IS_WHITESPACE(*ch)) {
5254 ch++;
5255 }
5256
5257 if (*ch == '\0') {
5258 /* last argument, no need to NUL-terminate */
5259 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5260 argstart = NULL;
5261 } else {
5262 /* NUL-terminate */
5263 *ch = '\0';
5264 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5265
5266 /*
5267 * Find the next string. We know spaces at the end of the string have already
5268 * been stripped.
5269 */
5270 argstart = ch + 1;
5271 while (IS_WHITESPACE(*argstart)) {
5272 argstart++;
5273 }
5274 }
5275
5276 /* Error-check, regardless of whether this is the last interpreter arg or not */
5277 if (error) {
5278 goto bad;
5279 }
5280 if (imgp->ip_argspace < new_ptr_size) {
5281 error = E2BIG;
5282 goto bad;
5283 }
5284 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5285 imgp->ip_argc++;
5286 }
5287
5288 if (argv != 0LL) {
5289 /*
5290 * If we are running an interpreter, replace the av[0] that was
5291 * passed to execve() with the path name that was
5292 * passed to execve() for interpreters which do not use the PATH
5293 * to locate their script arguments.
5294 */
5295 error = copyinptr(argv, &arg, ptr_size);
5296 if (error) {
5297 goto bad;
5298 }
5299 if (arg != 0LL) {
5300 argv += ptr_size; /* consume without using */
5301 }
5302 }
5303
5304 if (imgp->ip_interp_sugid_fd != -1) {
5305 char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
5306 snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
5307 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
5308 } else {
5309 error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
5310 }
5311
5312 if (error) {
5313 goto bad;
5314 }
5315 if (imgp->ip_argspace < new_ptr_size) {
5316 error = E2BIG;
5317 goto bad;
5318 }
5319 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5320 imgp->ip_argc++;
5321 }
5322
5323 while (argv != 0LL) {
5324 user_addr_t arg;
5325
5326 error = copyinptr(argv, &arg, ptr_size);
5327 if (error) {
5328 goto bad;
5329 }
5330
5331 if (arg == 0LL) {
5332 break;
5333 }
5334
5335 argv += ptr_size;
5336
5337 /*
5338 * av[n...] = arg[n]
5339 */
5340 error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
5341 if (error) {
5342 goto bad;
5343 }
5344 if (imgp->ip_argspace < new_ptr_size) {
5345 error = E2BIG;
5346 goto bad;
5347 }
5348 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5349 imgp->ip_argc++;
5350 }
5351
5352 /* Save space for argv[] NULL terminator */
5353 if (imgp->ip_argspace < new_ptr_size) {
5354 error = E2BIG;
5355 goto bad;
5356 }
5357 imgp->ip_argspace -= new_ptr_size;
5358
5359 /* Note where the args ends and env begins. */
5360 imgp->ip_endargv = imgp->ip_strendp;
5361 imgp->ip_envc = 0;
5362
5363 /* Now, get the environment */
5364 while (envv != 0LL) {
5365 user_addr_t env;
5366
5367 error = copyinptr(envv, &env, ptr_size);
5368 if (error) {
5369 goto bad;
5370 }
5371
5372 envv += ptr_size;
5373 if (env == 0LL) {
5374 break;
5375 }
5376 /*
5377 * av[n...] = env[n]
5378 */
5379 error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
5380 if (error) {
5381 goto bad;
5382 }
5383 if (imgp->ip_argspace < new_ptr_size) {
5384 error = E2BIG;
5385 goto bad;
5386 }
5387 imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
5388 imgp->ip_envc++;
5389 }
5390
5391 /* Save space for envv[] NULL terminator */
5392 if (imgp->ip_argspace < new_ptr_size) {
5393 error = E2BIG;
5394 goto bad;
5395 }
5396 imgp->ip_argspace -= new_ptr_size;
5397
5398 /* Align the tail of the combined argv+envv area */
5399 while (imgp->ip_strspace % new_ptr_size != 0) {
5400 if (imgp->ip_argspace < 1) {
5401 error = E2BIG;
5402 goto bad;
5403 }
5404 *imgp->ip_strendp++ = '\0';
5405 imgp->ip_strspace--;
5406 imgp->ip_argspace--;
5407 }
5408
5409 /* Note where the envv ends and applev begins. */
5410 imgp->ip_endenvv = imgp->ip_strendp;
5411
5412 /*
5413 * From now on, we are no longer charging argument
5414 * space to ip_argspace.
5415 */
5416
5417 bad:
5418 return error;
5419 }
5420
5421 /*
5422 * Libc has an 8-element array set up for stack guard values. It only fills
5423 * in one of those entries, and both gcc and llvm seem to use only a single
5424 * 8-byte guard. Until somebody needs more than an 8-byte guard value, don't
5425 * do the work to construct them.
5426 */
5427 #define GUARD_VALUES 1
5428 #define GUARD_KEY "stack_guard="
5429
5430 /*
5431 * System malloc needs some entropy when it is initialized.
5432 */
5433 #define ENTROPY_VALUES 2
5434 #define ENTROPY_KEY "malloc_entropy="
5435
5436 /*
5437 * libplatform needs a random pointer-obfuscation value when it is initialized.
5438 */
5439 #define PTR_MUNGE_VALUES 1
5440 #define PTR_MUNGE_KEY "ptr_munge="
5441
5442 /*
5443 * System malloc engages nanozone for UIAPP.
5444 */
5445 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
5446 /*
5447 * Used to pass experiment flags up to libmalloc.
5448 */
5449 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
5450
5451 #define PFZ_KEY "pfz="
5452 extern user32_addr_t commpage_text32_location;
5453 extern user64_addr_t commpage_text64_location;
5454
5455 extern uuid_string_t bootsessionuuid_string;
5456
5457 #define MAIN_STACK_VALUES 4
5458 #define MAIN_STACK_KEY "main_stack="
5459
5460 #define FSID_KEY "executable_file="
5461 #define DYLD_FSID_KEY "dyld_file="
5462 #define CDHASH_KEY "executable_cdhash="
5463 #define DYLD_FLAGS_KEY "dyld_flags="
5464 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
5465 #define APP_BOOT_SESSION_KEY "executable_boothash="
5466 #if __has_feature(ptrauth_calls)
5467 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
5468 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
5469 #endif /* __has_feature(ptrauth_calls) */
5470 #define MAIN_TH_PORT_KEY "th_port="
5471
5472 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
5473
5474 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
5475 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
5476
5477 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
5478 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
5479 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
5480
5481 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)5482 exec_add_entropy_key(struct image_params *imgp,
5483 const char *key,
5484 int values,
5485 boolean_t embedNUL)
5486 {
5487 const int limit = 8;
5488 uint64_t entropy[limit];
5489 char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
5490 if (values > limit) {
5491 values = limit;
5492 }
5493
5494 read_random(entropy, sizeof(entropy[0]) * values);
5495
5496 if (embedNUL) {
5497 entropy[0] &= ~(0xffull << 8);
5498 }
5499
5500 int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
5501 size_t remaining = sizeof(str) - len;
5502 for (int i = 1; i < values && remaining > 0; ++i) {
5503 size_t start = sizeof(str) - remaining;
5504 len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
5505 remaining -= len;
5506 }
5507
5508 return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
5509 }
5510
5511 /*
5512 * Build up the contents of the apple[] string vector
5513 */
5514 #if (DEVELOPMENT || DEBUG)
5515 extern uint64_t dyld_flags;
5516 #endif
5517
5518 #if __has_feature(ptrauth_calls)
5519 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)5520 is_arm64e_running_as_arm64(const struct image_params *imgp)
5521 {
5522 return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
5523 (imgp->ip_flags & IMGPF_NOJOP);
5524 }
5525 #endif /* __has_feature(ptrauth_calls) */
5526
5527 _Atomic uint64_t libmalloc_experiment_factors = 0;
5528
5529 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result)5530 exec_add_apple_strings(struct image_params *imgp,
5531 const load_result_t *load_result)
5532 {
5533 int error;
5534 int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5535 thread_t new_thread;
5536 ipc_port_t sright;
5537 uint64_t local_experiment_factors = 0;
5538
5539 /* exec_save_path stored the first string */
5540 imgp->ip_applec = 1;
5541
5542 /* adding the pfz string */
5543 {
5544 char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
5545
5546 if (img_ptr_size == 8) {
5547 __assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
5548 assert(ret < sizeof(pfz_string));
5549 } else {
5550 snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
5551 }
5552 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
5553 if (error) {
5554 printf("Failed to add the pfz string with error %d\n", error);
5555 goto bad;
5556 }
5557 imgp->ip_applec++;
5558 }
5559
5560 /* adding the NANO_ENGAGE_KEY key */
5561 if (imgp->ip_px_sa) {
5562 int proc_flags = (((struct _posix_spawnattr *) imgp->ip_px_sa)->psa_flags);
5563
5564 if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
5565 const char *nano_string = NANO_ENGAGE_KEY;
5566 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
5567 if (error) {
5568 goto bad;
5569 }
5570 imgp->ip_applec++;
5571 }
5572 }
5573
5574 /*
5575 * Supply libc with a collection of random values to use when
5576 * implementing -fstack-protector.
5577 *
5578 * (The first random string always contains an embedded NUL so that
5579 * __stack_chk_guard also protects against C string vulnerabilities)
5580 */
5581 error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
5582 if (error) {
5583 goto bad;
5584 }
5585 imgp->ip_applec++;
5586
5587 /*
5588 * Supply libc with entropy for system malloc.
5589 */
5590 error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
5591 if (error) {
5592 goto bad;
5593 }
5594 imgp->ip_applec++;
5595
5596 /*
5597 * Supply libpthread & libplatform with a random value to use for pointer
5598 * obfuscation.
5599 */
5600 error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
5601 if (error) {
5602 goto bad;
5603 }
5604 imgp->ip_applec++;
5605
5606 /*
5607 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
5608 * stack if it was allocated by the kernel.
5609 *
5610 * The guard page is not included in this stack size as libpthread
5611 * expects to add it back in after receiving this value.
5612 */
5613 if (load_result->unixproc) {
5614 char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
5615 snprintf(stack_string, sizeof(stack_string),
5616 MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
5617 (uint64_t)load_result->user_stack,
5618 (uint64_t)load_result->user_stack_size,
5619 (uint64_t)load_result->user_stack_alloc,
5620 (uint64_t)load_result->user_stack_alloc_size);
5621 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
5622 if (error) {
5623 goto bad;
5624 }
5625 imgp->ip_applec++;
5626 }
5627
5628 if (imgp->ip_vattr) {
5629 uint64_t fsid = vnode_get_va_fsid(imgp->ip_vattr);
5630 uint64_t fsobjid = imgp->ip_vattr->va_fileid;
5631
5632 char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
5633 snprintf(fsid_string, sizeof(fsid_string),
5634 FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
5635 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
5636 if (error) {
5637 goto bad;
5638 }
5639 imgp->ip_applec++;
5640 }
5641
5642 if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
5643 char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
5644 snprintf(fsid_string, sizeof(fsid_string),
5645 DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
5646 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
5647 if (error) {
5648 goto bad;
5649 }
5650 imgp->ip_applec++;
5651 }
5652
5653 uint8_t cdhash[SHA1_RESULTLEN];
5654 int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash);
5655 if (cdhash_errror == 0) {
5656 char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
5657 strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
5658 char *p = hash_string + sizeof(CDHASH_KEY) - 1;
5659 for (int i = 0; i < SHA1_RESULTLEN; i++) {
5660 snprintf(p, 3, "%02x", (int) cdhash[i]);
5661 p += 2;
5662 }
5663 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
5664 if (error) {
5665 goto bad;
5666 }
5667 imgp->ip_applec++;
5668
5669 /* hash together cd-hash and boot-session-uuid */
5670 uint8_t sha_digest[SHA256_DIGEST_LENGTH];
5671 SHA256_CTX sha_ctx;
5672 SHA256_Init(&sha_ctx);
5673 SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
5674 SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
5675 SHA256_Final(sha_digest, &sha_ctx);
5676 char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
5677 strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
5678 char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
5679 for (int i = 0; i < SHA1_RESULTLEN; i++) {
5680 snprintf(s, 3, "%02x", (int) sha_digest[i]);
5681 s += 2;
5682 }
5683 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
5684 if (error) {
5685 goto bad;
5686 }
5687 imgp->ip_applec++;
5688 }
5689 #if (DEVELOPMENT || DEBUG)
5690 if (dyld_flags) {
5691 char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
5692 snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
5693 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
5694 if (error) {
5695 goto bad;
5696 }
5697 imgp->ip_applec++;
5698 }
5699 #endif
5700 if (imgp->ip_subsystem_root_path) {
5701 size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
5702 char subsystem_root_path_string[buffer_len];
5703 int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
5704
5705 if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
5706 error = ENAMETOOLONG;
5707 goto bad;
5708 }
5709
5710 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
5711 if (error) {
5712 goto bad;
5713 }
5714
5715 imgp->ip_applec++;
5716 }
5717 #if __has_feature(ptrauth_calls)
5718 if (is_arm64e_running_as_arm64(imgp)) {
5719 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
5720 if (error) {
5721 goto bad;
5722 }
5723
5724 imgp->ip_applec++;
5725 }
5726 #endif /* __has_feature(ptrauth_calls) */
5727
5728
5729 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
5730 {
5731 char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
5732 strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
5733 bool allowAll = bootarg_arm64e_preview_abi;
5734 strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
5735 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
5736 if (error) {
5737 goto bad;
5738 }
5739
5740 imgp->ip_applec++;
5741 }
5742 #endif
5743 /*
5744 * Add main thread mach port name
5745 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
5746 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
5747 * against libpthread.
5748 */
5749 if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
5750 thread_reference(new_thread);
5751 sright = convert_thread_to_port_pinned(new_thread);
5752 task_t new_task = get_threadtask(new_thread);
5753 mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
5754 char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
5755 snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
5756
5757 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
5758 if (error) {
5759 goto bad;
5760 }
5761 imgp->ip_applec++;
5762 }
5763
5764 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
5765 if (imgp->ip_px_sa != NULL) {
5766 struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
5767 if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
5768 const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
5769 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
5770 if (error) {
5771 goto bad;
5772 }
5773 imgp->ip_applec++;
5774 }
5775 }
5776 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
5777
5778 /* adding the libmalloc experiment string */
5779 local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
5780 if (__improbable(local_experiment_factors != 0)) {
5781 char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
5782
5783 snprintf(
5784 libmalloc_experiment_factors_string,
5785 sizeof(libmalloc_experiment_factors_string),
5786 LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
5787 local_experiment_factors);
5788 error = exec_add_user_string(
5789 imgp,
5790 CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
5791 UIO_SYSSPACE,
5792 FALSE);
5793 if (error) {
5794 printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
5795 goto bad;
5796 }
5797 imgp->ip_applec++;
5798 }
5799
5800 /* Align the tail of the combined applev area */
5801 while (imgp->ip_strspace % img_ptr_size != 0) {
5802 *imgp->ip_strendp++ = '\0';
5803 imgp->ip_strspace--;
5804 }
5805
5806 bad:
5807 return error;
5808 }
5809
5810 /*
5811 * exec_check_permissions
5812 *
5813 * Description: Verify that the file that is being attempted to be executed
5814 * is in fact allowed to be executed based on it POSIX file
5815 * permissions and other access control criteria
5816 *
5817 * Parameters: struct image_params * the image parameter block
5818 *
5819 * Returns: 0 Success
5820 * EACCES Permission denied
5821 * ENOEXEC Executable file format error
5822 * ETXTBSY Text file busy [misuse of error code]
5823 * vnode_getattr:???
5824 * vnode_authorize:???
5825 */
5826 static int
exec_check_permissions(struct image_params * imgp)5827 exec_check_permissions(struct image_params *imgp)
5828 {
5829 struct vnode *vp = imgp->ip_vp;
5830 struct vnode_attr *vap = imgp->ip_vattr;
5831 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5832 int error;
5833 kauth_action_t action;
5834
5835 /* Only allow execution of regular files */
5836 if (!vnode_isreg(vp)) {
5837 return EACCES;
5838 }
5839
5840 /* Get the file attributes that we will be using here and elsewhere */
5841 VATTR_INIT(vap);
5842 VATTR_WANTED(vap, va_uid);
5843 VATTR_WANTED(vap, va_gid);
5844 VATTR_WANTED(vap, va_mode);
5845 VATTR_WANTED(vap, va_fsid);
5846 VATTR_WANTED(vap, va_fsid64);
5847 VATTR_WANTED(vap, va_fileid);
5848 VATTR_WANTED(vap, va_data_size);
5849 if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
5850 return error;
5851 }
5852
5853 /*
5854 * Ensure that at least one execute bit is on - otherwise root
5855 * will always succeed, and we don't want to happen unless the
5856 * file really is executable.
5857 */
5858 if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
5859 return EACCES;
5860 }
5861
5862 /* Disallow zero length files */
5863 if (vap->va_data_size == 0) {
5864 return ENOEXEC;
5865 }
5866
5867 imgp->ip_arch_offset = (user_size_t)0;
5868 #if __LP64__
5869 imgp->ip_arch_size = vap->va_data_size;
5870 #else
5871 if (vap->va_data_size > UINT32_MAX) {
5872 return ENOEXEC;
5873 }
5874 imgp->ip_arch_size = (user_size_t)vap->va_data_size;
5875 #endif
5876
5877 /* Disable setuid-ness for traced programs or if MNT_NOSUID */
5878 if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
5879 vap->va_mode &= ~(VSUID | VSGID);
5880 }
5881
5882 /*
5883 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
5884 * flags for setuid/setgid binaries.
5885 */
5886 if (vap->va_mode & (VSUID | VSGID)) {
5887 imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
5888 }
5889
5890 #if CONFIG_MACF
5891 error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
5892 if (error) {
5893 return error;
5894 }
5895 #endif
5896
5897 /* Check for execute permission */
5898 action = KAUTH_VNODE_EXECUTE;
5899 /* Traced images must also be readable */
5900 if (p->p_lflag & P_LTRACED) {
5901 action |= KAUTH_VNODE_READ_DATA;
5902 }
5903 if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
5904 return error;
5905 }
5906
5907 #if 0
5908 /* Don't let it run if anyone had it open for writing */
5909 vnode_lock(vp);
5910 if (vp->v_writecount) {
5911 panic("going to return ETXTBSY %x", vp);
5912 vnode_unlock(vp);
5913 return ETXTBSY;
5914 }
5915 vnode_unlock(vp);
5916 #endif
5917
5918 /* XXX May want to indicate to underlying FS that vnode is open */
5919
5920 return error;
5921 }
5922
5923
5924 /*
5925 * exec_handle_sugid
5926 *
5927 * Initially clear the P_SUGID in the process flags; if an SUGID process is
5928 * exec'ing a non-SUGID image, then this is the point of no return.
5929 *
5930 * If the image being activated is SUGID, then replace the credential with a
5931 * copy, disable tracing (unless the tracing process is root), reset the
5932 * mach task port to revoke it, set the P_SUGID bit,
5933 *
5934 * If the saved user and group ID will be changing, then make sure it happens
5935 * to a new credential, rather than a shared one.
5936 *
5937 * Set the security token (this is probably obsolete, given that the token
5938 * should not technically be separate from the credential itself).
5939 *
5940 * Parameters: struct image_params * the image parameter block
5941 *
5942 * Returns: void No failure indication
5943 *
5944 * Implicit returns:
5945 * <process credential> Potentially modified/replaced
5946 * <task port> Potentially revoked
5947 * <process flags> P_SUGID bit potentially modified
5948 * <security token> Potentially modified
5949 */
5950 __attribute__((noinline))
5951 static int
exec_handle_sugid(struct image_params * imgp)5952 exec_handle_sugid(struct image_params *imgp)
5953 {
5954 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5955 kauth_cred_t cred = vfs_context_ucred(imgp->ip_vfs_context);
5956 int i;
5957 int leave_sugid_clear = 0;
5958 int mac_reset_ipc = 0;
5959 int error = 0;
5960 task_t task = NULL;
5961 #if CONFIG_MACF
5962 int mac_transition, disjoint_cred = 0;
5963 int label_update_return = 0;
5964
5965 /*
5966 * Determine whether a call to update the MAC label will result in the
5967 * credential changing.
5968 *
5969 * Note: MAC policies which do not actually end up modifying
5970 * the label subsequently are strongly encouraged to
5971 * return 0 for this check, since a non-zero answer will
5972 * slow down the exec fast path for normal binaries.
5973 */
5974 mac_transition = mac_cred_check_label_update_execve(
5975 imgp->ip_vfs_context,
5976 imgp->ip_vp,
5977 imgp->ip_arch_offset,
5978 imgp->ip_scriptvp,
5979 imgp->ip_scriptlabelp,
5980 imgp->ip_execlabelp,
5981 p,
5982 &imgp->ip_px_smpx);
5983 #endif
5984
5985 OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
5986
5987 /*
5988 * Order of the following is important; group checks must go last,
5989 * as we use the success of the 'ismember' check combined with the
5990 * failure of the explicit match to indicate that we will be setting
5991 * the egid of the process even though the new process did not
5992 * require VSUID/VSGID bits in order for it to set the new group as
5993 * its egid.
5994 *
5995 * Note: Technically, by this we are implying a call to
5996 * setegid() in the new process, rather than implying
5997 * it used its VSGID bit to set the effective group,
5998 * even though there is no code in that process to make
5999 * such a call.
6000 */
6001 if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
6002 kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
6003 ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
6004 ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
6005 (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid))) ||
6006 (imgp->ip_sc_port != NULL)) {
6007 #if CONFIG_MACF
6008 /* label for MAC transition and neither VSUID nor VSGID */
6009 handle_mac_transition:
6010 #endif
6011
6012 #if CONFIG_SETUID
6013 /*
6014 * Replace the credential with a copy of itself if euid or
6015 * egid change.
6016 *
6017 * Note: setuid binaries will automatically opt out of
6018 * group resolver participation as a side effect
6019 * of this operation. This is an intentional
6020 * part of the security model, which requires a
6021 * participating credential be established by
6022 * escalating privilege, setting up all other
6023 * aspects of the credential including whether
6024 * or not to participate in external group
6025 * membership resolution, then dropping their
6026 * effective privilege to that of the desired
6027 * final credential state.
6028 *
6029 * Modifications to p_ucred must be guarded using the
6030 * proc's ucred lock. This prevents others from accessing
6031 * a garbage credential.
6032 */
6033
6034 if (imgp->ip_sc_port != NULL) {
6035 extern int suid_cred_verify(ipc_port_t, vnode_t, uint32_t *);
6036 int ret = -1;
6037 uid_t uid = UINT32_MAX;
6038
6039 /*
6040 * Check that the vnodes match. If a script is being
6041 * executed check the script's vnode rather than the
6042 * interpreter's.
6043 */
6044 struct vnode *vp = imgp->ip_scriptvp != NULL ? imgp->ip_scriptvp : imgp->ip_vp;
6045
6046 ret = suid_cred_verify(imgp->ip_sc_port, vp, &uid);
6047 if (ret == 0) {
6048 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred) {
6049 return kauth_cred_setresuid(my_cred,
6050 KAUTH_UID_NONE,
6051 uid,
6052 uid,
6053 KAUTH_UID_NONE);
6054 });
6055 } else {
6056 error = EPERM;
6057 }
6058 }
6059
6060 if (imgp->ip_origvattr->va_mode & VSUID) {
6061 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred) {
6062 return kauth_cred_setresuid(my_cred,
6063 KAUTH_UID_NONE,
6064 imgp->ip_origvattr->va_uid,
6065 imgp->ip_origvattr->va_uid,
6066 KAUTH_UID_NONE);
6067 });
6068 }
6069
6070 if (imgp->ip_origvattr->va_mode & VSGID) {
6071 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred) {
6072 return kauth_cred_setresgid(my_cred,
6073 KAUTH_GID_NONE,
6074 imgp->ip_origvattr->va_gid,
6075 imgp->ip_origvattr->va_gid);
6076 });
6077 }
6078 #endif /* CONFIG_SETUID */
6079
6080 #if CONFIG_MACF
6081 /*
6082 * If a policy has indicated that it will transition the label,
6083 * before making the call into the MAC policies, get a new
6084 * duplicate credential, so they can modify it without
6085 * modifying any others sharing it.
6086 */
6087 if (mac_transition) {
6088 /*
6089 * This hook may generate upcalls that require
6090 * importance donation from the kernel.
6091 * (23925818)
6092 */
6093 thread_t thread = current_thread();
6094 thread_enable_send_importance(thread, TRUE);
6095 kauth_proc_label_update_execve(p,
6096 imgp->ip_vfs_context,
6097 imgp->ip_vp,
6098 imgp->ip_arch_offset,
6099 imgp->ip_scriptvp,
6100 imgp->ip_scriptlabelp,
6101 imgp->ip_execlabelp,
6102 &imgp->ip_csflags,
6103 &imgp->ip_px_smpx,
6104 &disjoint_cred, /* will be non zero if disjoint */
6105 &label_update_return);
6106 thread_enable_send_importance(thread, FALSE);
6107
6108 if (disjoint_cred) {
6109 /*
6110 * If updating the MAC label resulted in a
6111 * disjoint credential, flag that we need to
6112 * set the P_SUGID bit. This protects
6113 * against debuggers being attached by an
6114 * insufficiently privileged process onto the
6115 * result of a transition to a more privileged
6116 * credential.
6117 */
6118 leave_sugid_clear = 0;
6119 }
6120
6121 imgp->ip_mac_return = label_update_return;
6122 }
6123
6124 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);
6125
6126 #endif /* CONFIG_MACF */
6127
6128 /*
6129 * If 'leave_sugid_clear' is non-zero, then we passed the
6130 * VSUID and MACF checks, and successfully determined that
6131 * the previous cred was a member of the VSGID group, but
6132 * that it was not the default at the time of the execve,
6133 * and that the post-labelling credential was not disjoint.
6134 * So we don't set the P_SUGID or reset mach ports and fds
6135 * on the basis of simply running this code.
6136 */
6137 if (mac_reset_ipc || !leave_sugid_clear) {
6138 /*
6139 * Have mach reset the task and thread ports.
6140 * We don't want anyone who had the ports before
6141 * a setuid exec to be able to access/control the
6142 * task/thread after.
6143 */
6144 ipc_task_reset((imgp->ip_new_thread != NULL) ?
6145 get_threadtask(imgp->ip_new_thread) : p->task);
6146 ipc_thread_reset((imgp->ip_new_thread != NULL) ?
6147 imgp->ip_new_thread : current_thread());
6148 }
6149
6150 if (!leave_sugid_clear) {
6151 /*
6152 * Flag the process as setuid.
6153 */
6154 OSBitOrAtomic(P_SUGID, &p->p_flag);
6155
6156 /*
6157 * Radar 2261856; setuid security hole fix
6158 * XXX For setuid processes, attempt to ensure that
6159 * stdin, stdout, and stderr are already allocated.
6160 * We do not want userland to accidentally allocate
6161 * descriptors in this range which has implied meaning
6162 * to libc.
6163 */
6164 for (i = 0; i < 3; i++) {
6165 if (fp_get_noref_locked(p, i) != NULL) {
6166 continue;
6167 }
6168
6169 /*
6170 * Do the kernel equivalent of
6171 *
6172 * if i == 0
6173 * (void) open("/dev/null", O_RDONLY);
6174 * else
6175 * (void) open("/dev/null", O_WRONLY);
6176 */
6177
6178 struct fileproc *fp;
6179 int indx;
6180 int flag;
6181 struct nameidata *ndp = NULL;
6182
6183 if (i == 0) {
6184 flag = FREAD;
6185 } else {
6186 flag = FWRITE;
6187 }
6188
6189 if ((error = falloc(p,
6190 &fp, &indx, imgp->ip_vfs_context)) != 0) {
6191 continue;
6192 }
6193
6194 ndp = kalloc_type(struct nameidata,
6195 Z_WAITOK | Z_ZERO | Z_NOFAIL);
6196
6197 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
6198 CAST_USER_ADDR_T("/dev/null"),
6199 imgp->ip_vfs_context);
6200
6201 if ((error = vn_open(ndp, flag, 0)) != 0) {
6202 fp_free(p, indx, fp);
6203 kfree_type(struct nameidata, ndp);
6204 break;
6205 }
6206
6207 struct fileglob *fg = fp->fp_glob;
6208
6209 fg->fg_flag = flag;
6210 fg->fg_ops = &vnops;
6211 fp_set_data(fp, ndp->ni_vp);
6212
6213 vnode_put(ndp->ni_vp);
6214
6215 proc_fdlock(p);
6216 procfdtbl_releasefd(p, indx, NULL);
6217 fp_drop(p, indx, fp, 1);
6218 proc_fdunlock(p);
6219
6220 kfree_type(struct nameidata, ndp);
6221 }
6222 }
6223 }
6224 #if CONFIG_MACF
6225 else {
6226 /*
6227 * We are here because we were told that the MAC label will
6228 * be transitioned, and the binary is not VSUID or VSGID; to
6229 * deal with this case, we could either duplicate a lot of
6230 * code, or we can indicate we want to default the P_SUGID
6231 * bit clear and jump back up.
6232 */
6233 if (mac_transition) {
6234 leave_sugid_clear = 1;
6235 goto handle_mac_transition;
6236 }
6237 }
6238
6239 #endif /* CONFIG_MACF */
6240
6241 /*
6242 * Implement the semantic where the effective user and group become
6243 * the saved user and group in exec'ed programs.
6244 *
6245 * Modifications to p_ucred must be guarded using the
6246 * proc's ucred lock. This prevents others from accessing
6247 * a garbage credential.
6248 */
6249 proc_update_label(p, false, ^kauth_cred_t (kauth_cred_t my_cred) {
6250 return kauth_cred_setsvuidgid(my_cred,
6251 kauth_cred_getuid(my_cred),
6252 kauth_cred_getgid(my_cred));
6253 });
6254
6255 if (imgp->ip_new_thread != NULL) {
6256 task = get_threadtask(imgp->ip_new_thread);
6257 } else {
6258 task = p->task;
6259 }
6260
6261 /* Update the process' identity version and set the security token */
6262 proc_setpidversion(p, OSIncrementAtomic(&nextpidversion));
6263 task_set_uniqueid(task);
6264 set_security_token_task_internal(p, task);
6265
6266 return error;
6267 }
6268
6269
6270 /*
6271 * create_unix_stack
6272 *
6273 * Description: Set the user stack address for the process to the provided
6274 * address. If a custom stack was not set as a result of the
6275 * load process (i.e. as specified by the image file for the
6276 * executable), then allocate the stack in the provided map and
6277 * set up appropriate guard pages for enforcing administrative
6278 * limits on stack growth, if they end up being needed.
6279 *
6280 * Parameters: p Process to set stack on
6281 * load_result Information from mach-o load commands
6282 * map Address map in which to allocate the new stack
6283 *
6284 * Returns: KERN_SUCCESS Stack successfully created
6285 * !KERN_SUCCESS Mach failure code
6286 */
6287 __attribute__((noinline))
6288 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)6289 create_unix_stack(vm_map_t map, load_result_t* load_result,
6290 proc_t p)
6291 {
6292 mach_vm_size_t size, prot_size;
6293 mach_vm_offset_t addr, prot_addr;
6294 kern_return_t kr;
6295
6296 mach_vm_address_t user_stack = load_result->user_stack;
6297
6298 proc_lock(p);
6299 p->user_stack = (uintptr_t)user_stack;
6300 if (load_result->custom_stack) {
6301 p->p_lflag |= P_LCUSTOM_STACK;
6302 }
6303 proc_unlock(p);
6304 if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
6305 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);
6306 }
6307
6308 if (load_result->user_stack_alloc_size > 0) {
6309 /*
6310 * Allocate enough space for the maximum stack size we
6311 * will ever authorize and an extra page to act as
6312 * a guard page for stack overflows. For default stacks,
6313 * vm_initial_limit_stack takes care of the extra guard page.
6314 * Otherwise we must allocate it ourselves.
6315 */
6316 if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
6317 return KERN_INVALID_ARGUMENT;
6318 }
6319 addr = vm_map_trunc_page(load_result->user_stack - size,
6320 vm_map_page_mask(map));
6321 kr = mach_vm_allocate_kernel(map, &addr, size,
6322 VM_FLAGS_FIXED, VM_MEMORY_STACK);
6323 if (kr != KERN_SUCCESS) {
6324 // Can't allocate at default location, try anywhere
6325 addr = 0;
6326 kr = mach_vm_allocate_kernel(map, &addr, size,
6327 VM_FLAGS_ANYWHERE, VM_MEMORY_STACK);
6328 if (kr != KERN_SUCCESS) {
6329 return kr;
6330 }
6331
6332 user_stack = addr + size;
6333 load_result->user_stack = (user_addr_t)user_stack;
6334
6335 proc_lock(p);
6336 p->user_stack = (uintptr_t)user_stack;
6337 proc_unlock(p);
6338 }
6339
6340 load_result->user_stack_alloc = (user_addr_t)addr;
6341
6342 /*
6343 * And prevent access to what's above the current stack
6344 * size limit for this process.
6345 */
6346 if (load_result->user_stack_size == 0) {
6347 load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
6348 prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
6349 } else {
6350 prot_size = PAGE_SIZE;
6351 }
6352
6353 prot_addr = addr;
6354 kr = mach_vm_protect(map,
6355 prot_addr,
6356 prot_size,
6357 FALSE,
6358 VM_PROT_NONE);
6359 if (kr != KERN_SUCCESS) {
6360 (void)mach_vm_deallocate(map, addr, size);
6361 return kr;
6362 }
6363 }
6364
6365 return KERN_SUCCESS;
6366 }
6367
6368 #include <sys/reboot.h>
6369
6370 /*
6371 * load_init_program_at_path
6372 *
6373 * Description: Load the "init" program; in most cases, this will be "launchd"
6374 *
6375 * Parameters: p Process to call execve() to create
6376 * the "init" program
6377 * scratch_addr Page in p, scratch space
6378 * path NULL terminated path
6379 *
6380 * Returns: KERN_SUCCESS Success
6381 * !KERN_SUCCESS See execve/mac_execve for error codes
6382 *
6383 * Notes: The process that is passed in is the first manufactured
6384 * process on the system, and gets here via bsd_ast() firing
6385 * for the first time. This is done to ensure that bsd_init()
6386 * has run to completion.
6387 *
6388 * The address map of the first manufactured process matches the
6389 * word width of the kernel. Once the self-exec completes, the
6390 * initproc might be different.
6391 */
6392 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)6393 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
6394 {
6395 int retval[2];
6396 int error;
6397 struct execve_args init_exec_args;
6398 user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
6399
6400 /*
6401 * Validate inputs and pre-conditions
6402 */
6403 assert(p);
6404 assert(scratch_addr);
6405 assert(path);
6406
6407 /*
6408 * Copy out program name.
6409 */
6410 size_t path_length = strlen(path) + 1;
6411 argv0 = scratch_addr;
6412 error = copyout(path, argv0, path_length);
6413 if (error) {
6414 return error;
6415 }
6416
6417 scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
6418
6419 /*
6420 * Put out first (and only) argument, similarly.
6421 * Assumes everything fits in a page as allocated above.
6422 */
6423 if (boothowto & RB_SINGLE) {
6424 const char *init_args = "-s";
6425 size_t init_args_length = strlen(init_args) + 1;
6426
6427 argv1 = scratch_addr;
6428 error = copyout(init_args, argv1, init_args_length);
6429 if (error) {
6430 return error;
6431 }
6432
6433 scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
6434 }
6435
6436 if (proc_is64bit(p)) {
6437 user64_addr_t argv64bit[3] = {};
6438
6439 argv64bit[0] = argv0;
6440 argv64bit[1] = argv1;
6441 argv64bit[2] = USER_ADDR_NULL;
6442
6443 error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
6444 if (error) {
6445 return error;
6446 }
6447 } else {
6448 user32_addr_t argv32bit[3] = {};
6449
6450 argv32bit[0] = (user32_addr_t)argv0;
6451 argv32bit[1] = (user32_addr_t)argv1;
6452 argv32bit[2] = USER_ADDR_NULL;
6453
6454 error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
6455 if (error) {
6456 return error;
6457 }
6458 }
6459
6460 /*
6461 * Set up argument block for fake call to execve.
6462 */
6463 init_exec_args.fname = argv0;
6464 init_exec_args.argp = scratch_addr;
6465 init_exec_args.envp = USER_ADDR_NULL;
6466
6467 /*
6468 * So that init task is set with uid,gid 0 token
6469 */
6470 set_security_token(p);
6471
6472 return execve(p, &init_exec_args, retval);
6473 }
6474
6475 static const char * init_programs[] = {
6476 #if DEBUG
6477 "/usr/appleinternal/sbin/launchd.debug",
6478 #endif
6479 #if DEVELOPMENT || DEBUG
6480 "/usr/appleinternal/sbin/launchd.development",
6481 #endif
6482 "/sbin/launchd",
6483 };
6484
6485 /*
6486 * load_init_program
6487 *
6488 * Description: Load the "init" program; in most cases, this will be "launchd"
6489 *
6490 * Parameters: p Process to call execve() to create
6491 * the "init" program
6492 *
6493 * Returns: (void)
6494 *
6495 * Notes: The process that is passed in is the first manufactured
6496 * process on the system, and gets here via bsd_ast() firing
6497 * for the first time. This is done to ensure that bsd_init()
6498 * has run to completion.
6499 *
6500 * In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
6501 * may be used to select a specific launchd executable. As with
6502 * the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
6503 * will force /sbin/launchd to be selected.
6504 *
6505 * Search order by build:
6506 *
6507 * DEBUG DEVELOPMENT RELEASE PATH
6508 * ----------------------------------------------------------------------------------
6509 * 1 1 NA /usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
6510 * 2 NA NA /usr/appleinternal/sbin/launchd.debug
6511 * 3 2 NA /usr/appleinternal/sbin/launchd.development
6512 * 4 3 1 /sbin/launchd
6513 */
6514 void
load_init_program(proc_t p)6515 load_init_program(proc_t p)
6516 {
6517 uint32_t i;
6518 int error;
6519 vm_map_t map = current_map();
6520 mach_vm_offset_t scratch_addr = 0;
6521 mach_vm_size_t map_page_size = vm_map_page_size(map);
6522
6523 (void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size, VM_FLAGS_ANYWHERE, VM_KERN_MEMORY_NONE);
6524 #if CONFIG_MEMORYSTATUS
6525 (void) memorystatus_init_at_boot_snapshot();
6526 #endif /* CONFIG_MEMORYSTATUS */
6527
6528 #if DEBUG || DEVELOPMENT
6529 /* Check for boot-arg suffix first */
6530 char launchd_suffix[64];
6531 if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
6532 char launchd_path[128];
6533 boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
6534 (strcmp(launchd_suffix, "release") == 0));
6535
6536 if (is_release_suffix) {
6537 printf("load_init_program: attempting to load /sbin/launchd\n");
6538 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
6539 if (!error) {
6540 return;
6541 }
6542
6543 panic("Process 1 exec of launchd.release failed, errno %d", error);
6544 } else {
6545 strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
6546 strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
6547
6548 printf("load_init_program: attempting to load %s\n", launchd_path);
6549 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
6550 if (!error) {
6551 return;
6552 } else if (error != ENOENT) {
6553 printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
6554 }
6555 }
6556 }
6557 #endif
6558
6559 error = ENOENT;
6560 for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
6561 printf("load_init_program: attempting to load %s\n", init_programs[i]);
6562 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
6563 if (!error) {
6564 return;
6565 } else if (error != ENOENT) {
6566 printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
6567 }
6568 }
6569
6570 panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
6571 }
6572
6573 /*
6574 * load_return_to_errno
6575 *
6576 * Description: Convert a load_return_t (Mach error) to an errno (BSD error)
6577 *
6578 * Parameters: lrtn Mach error number
6579 *
6580 * Returns: (int) BSD error number
6581 * 0 Success
6582 * EBADARCH Bad architecture
6583 * EBADMACHO Bad Mach object file
6584 * ESHLIBVERS Bad shared library version
6585 * ENOMEM Out of memory/resource shortage
6586 * EACCES Access denied
6587 * ENOENT Entry not found (usually "file does
6588 * does not exist")
6589 * EIO An I/O error occurred
6590 * EBADEXEC The executable is corrupt/unknown
6591 */
6592 static int
load_return_to_errno(load_return_t lrtn)6593 load_return_to_errno(load_return_t lrtn)
6594 {
6595 switch (lrtn) {
6596 case LOAD_SUCCESS:
6597 return 0;
6598 case LOAD_BADARCH:
6599 return EBADARCH;
6600 case LOAD_BADMACHO:
6601 case LOAD_BADMACHO_UPX:
6602 return EBADMACHO;
6603 case LOAD_SHLIB:
6604 return ESHLIBVERS;
6605 case LOAD_NOSPACE:
6606 case LOAD_RESOURCE:
6607 return ENOMEM;
6608 case LOAD_PROTECT:
6609 return EACCES;
6610 case LOAD_ENOENT:
6611 return ENOENT;
6612 case LOAD_IOERROR:
6613 return EIO;
6614 case LOAD_DECRYPTFAIL:
6615 return EAUTH;
6616 case LOAD_FAILURE:
6617 default:
6618 return EBADEXEC;
6619 }
6620 }
6621
6622 #include <mach/mach_types.h>
6623 #include <mach/vm_prot.h>
6624 #include <mach/semaphore.h>
6625 #include <mach/sync_policy.h>
6626 #include <kern/clock.h>
6627 #include <mach/kern_return.h>
6628
6629 /*
6630 * execargs_alloc
6631 *
6632 * Description: Allocate the block of memory used by the execve arguments.
6633 * At the same time, we allocate a page so that we can read in
6634 * the first page of the image.
6635 *
6636 * Parameters: struct image_params * the image parameter block
6637 *
6638 * Returns: 0 Success
6639 * EINVAL Invalid argument
6640 * EACCES Permission denied
6641 * EINTR Interrupted function
6642 * ENOMEM Not enough space
6643 *
6644 * Notes: This is a temporary allocation into the kernel address space
6645 * to enable us to copy arguments in from user space. This is
6646 * necessitated by not mapping the process calling execve() into
6647 * the kernel address space during the execve() system call.
6648 *
6649 * We assemble the argument and environment, etc., into this
6650 * region before copying it as a single block into the child
6651 * process address space (at the top or bottom of the stack,
6652 * depending on which way the stack grows; see the function
6653 * exec_copyout_strings() for details).
6654 *
6655 * This ends up with a second (possibly unnecessary) copy compared
6656 * with assembing the data directly into the child address space,
6657 * instead, but since we cannot be guaranteed that the parent has
6658 * not modified its environment, we can't really know that it's
6659 * really a block there as well.
6660 */
6661
6662
6663 static int execargs_waiters = 0;
6664 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
6665
6666 static void
execargs_lock_lock(void)6667 execargs_lock_lock(void)
6668 {
6669 lck_mtx_lock_spin(&execargs_cache_lock);
6670 }
6671
6672 static void
execargs_lock_unlock(void)6673 execargs_lock_unlock(void)
6674 {
6675 lck_mtx_unlock(&execargs_cache_lock);
6676 }
6677
6678 static wait_result_t
execargs_lock_sleep(void)6679 execargs_lock_sleep(void)
6680 {
6681 return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
6682 }
6683
6684 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)6685 execargs_purgeable_allocate(char **execarg_address)
6686 {
6687 kern_return_t kr = vm_allocate_kernel(bsd_pageable_map, (vm_offset_t *)execarg_address, BSD_PAGEABLE_SIZE_PER_EXEC, VM_FLAGS_ANYWHERE | VM_FLAGS_PURGABLE, VM_KERN_MEMORY_NONE);
6688 assert(kr == KERN_SUCCESS);
6689 return kr;
6690 }
6691
6692 static kern_return_t
execargs_purgeable_reference(void * execarg_address)6693 execargs_purgeable_reference(void *execarg_address)
6694 {
6695 int state = VM_PURGABLE_NONVOLATILE;
6696 kern_return_t kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
6697
6698 assert(kr == KERN_SUCCESS);
6699 return kr;
6700 }
6701
6702 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)6703 execargs_purgeable_volatilize(void *execarg_address)
6704 {
6705 int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
6706 kern_return_t kr;
6707 kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
6708
6709 assert(kr == KERN_SUCCESS);
6710
6711 return kr;
6712 }
6713
6714 static void
execargs_wakeup_waiters(void)6715 execargs_wakeup_waiters(void)
6716 {
6717 thread_wakeup(&execargs_free_count);
6718 }
6719
6720 static int
execargs_alloc(struct image_params * imgp)6721 execargs_alloc(struct image_params *imgp)
6722 {
6723 kern_return_t kret;
6724 wait_result_t res;
6725 int i, cache_index = -1;
6726
6727 execargs_lock_lock();
6728
6729 while (execargs_free_count == 0) {
6730 execargs_waiters++;
6731 res = execargs_lock_sleep();
6732 execargs_waiters--;
6733 if (res != THREAD_AWAKENED) {
6734 execargs_lock_unlock();
6735 return EINTR;
6736 }
6737 }
6738
6739 execargs_free_count--;
6740
6741 for (i = 0; i < execargs_cache_size; i++) {
6742 vm_offset_t element = execargs_cache[i];
6743 if (element) {
6744 cache_index = i;
6745 imgp->ip_strings = (char *)(execargs_cache[i]);
6746 execargs_cache[i] = 0;
6747 break;
6748 }
6749 }
6750
6751 assert(execargs_free_count >= 0);
6752
6753 execargs_lock_unlock();
6754
6755 if (cache_index == -1) {
6756 kret = execargs_purgeable_allocate(&imgp->ip_strings);
6757 } else {
6758 kret = execargs_purgeable_reference(imgp->ip_strings);
6759 }
6760
6761 assert(kret == KERN_SUCCESS);
6762 if (kret != KERN_SUCCESS) {
6763 return ENOMEM;
6764 }
6765
6766 /* last page used to read in file headers */
6767 imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
6768 imgp->ip_strendp = imgp->ip_strings;
6769 imgp->ip_argspace = NCARGS;
6770 imgp->ip_strspace = (NCARGS + PAGE_SIZE);
6771
6772 return 0;
6773 }
6774
6775 /*
6776 * execargs_free
6777 *
6778 * Description: Free the block of memory used by the execve arguments and the
6779 * first page of the executable by a previous call to the function
6780 * execargs_alloc().
6781 *
6782 * Parameters: struct image_params * the image parameter block
6783 *
6784 * Returns: 0 Success
6785 * EINVAL Invalid argument
6786 * EINTR Oeration interrupted
6787 */
6788 static int
execargs_free(struct image_params * imgp)6789 execargs_free(struct image_params *imgp)
6790 {
6791 kern_return_t kret;
6792 int i;
6793 boolean_t needs_wakeup = FALSE;
6794
6795 kret = execargs_purgeable_volatilize(imgp->ip_strings);
6796
6797 execargs_lock_lock();
6798 execargs_free_count++;
6799
6800 for (i = 0; i < execargs_cache_size; i++) {
6801 vm_offset_t element = execargs_cache[i];
6802 if (element == 0) {
6803 execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
6804 imgp->ip_strings = NULL;
6805 break;
6806 }
6807 }
6808
6809 assert(imgp->ip_strings == NULL);
6810
6811 if (execargs_waiters > 0) {
6812 needs_wakeup = TRUE;
6813 }
6814
6815 execargs_lock_unlock();
6816
6817 if (needs_wakeup == TRUE) {
6818 execargs_wakeup_waiters();
6819 }
6820
6821 return kret == KERN_SUCCESS ? 0 : EINVAL;
6822 }
6823
6824 static void
exec_resettextvp(proc_t p,struct image_params * imgp)6825 exec_resettextvp(proc_t p, struct image_params *imgp)
6826 {
6827 vnode_t vp;
6828 off_t offset;
6829 vnode_t tvp = p->p_textvp;
6830 int ret;
6831
6832 vp = imgp->ip_vp;
6833 offset = imgp->ip_arch_offset;
6834
6835 if (vp == NULLVP) {
6836 panic("exec_resettextvp: expected valid vp");
6837 }
6838
6839 ret = vnode_ref(vp);
6840 proc_lock(p);
6841 if (ret == 0) {
6842 p->p_textvp = vp;
6843 p->p_textoff = offset;
6844 } else {
6845 p->p_textvp = NULLVP; /* this is paranoia */
6846 p->p_textoff = 0;
6847 }
6848 proc_unlock(p);
6849
6850 if (tvp != NULLVP) {
6851 if (vnode_getwithref(tvp) == 0) {
6852 vnode_rele(tvp);
6853 vnode_put(tvp);
6854 }
6855 }
6856 }
6857
6858 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
6859 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
6860
6861 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)6862 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
6863 {
6864 static char const nibble[] = "0123456789abcdef";
6865
6866 /* Apparently still the safest way to get a hex representation
6867 * of binary data.
6868 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
6869 * <rdar://problem/33328859> confusion around %*D/%nD in printf
6870 */
6871 for (int i = 0; i < CS_CDHASH_LEN; ++i) {
6872 str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
6873 str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
6874 }
6875 str[CS_CDHASH_STRING_SIZE - 1] = 0;
6876 }
6877
6878 /*
6879 * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
6880 *
6881 * Description: Waits for the userspace daemon to respond to the request
6882 * we made. Function declared non inline to be visible in
6883 * stackshots and spindumps as well as debugging.
6884 */
6885 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)6886 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
6887 {
6888 return find_code_signature(task_access_port, new_pid);
6889 }
6890
6891 static int
check_for_signature(proc_t p,struct image_params * imgp)6892 check_for_signature(proc_t p, struct image_params *imgp)
6893 {
6894 mach_port_t port = IPC_PORT_NULL;
6895 kern_return_t kr = KERN_FAILURE;
6896 int error = EACCES;
6897 boolean_t unexpected_failure = FALSE;
6898 struct cs_blob *csb;
6899 boolean_t require_success = FALSE;
6900 int spawn = (imgp->ip_flags & IMGPF_SPAWN);
6901 const int vfexec = 0;
6902 os_reason_t signature_failure_reason = OS_REASON_NULL;
6903
6904 /*
6905 * Override inherited code signing flags with the
6906 * ones for the process that is being successfully
6907 * loaded
6908 */
6909 proc_lock(p);
6910 proc_csflags_update(p, imgp->ip_csflags);
6911 proc_unlock(p);
6912
6913 /* Set the switch_protect flag on the map */
6914 if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
6915 vm_map_switch_protect(get_task_map(p->task), TRUE);
6916 }
6917 /* set the cs_enforced flags in the map */
6918 if (proc_getcsflags(p) & CS_ENFORCEMENT) {
6919 vm_map_cs_enforcement_set(get_task_map(p->task), TRUE);
6920 } else {
6921 vm_map_cs_enforcement_set(get_task_map(p->task), FALSE);
6922 }
6923
6924 /*
6925 * image activation may be failed due to policy
6926 * which is unexpected but security framework does not
6927 * approve of exec, kill and return immediately.
6928 */
6929 if (imgp->ip_mac_return != 0) {
6930 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
6931 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
6932 signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
6933 error = imgp->ip_mac_return;
6934 unexpected_failure = TRUE;
6935 goto done;
6936 }
6937
6938 if (imgp->ip_cs_error != OS_REASON_NULL) {
6939 signature_failure_reason = imgp->ip_cs_error;
6940 imgp->ip_cs_error = OS_REASON_NULL;
6941 error = EACCES;
6942 goto done;
6943 }
6944
6945 #if XNU_TARGET_OS_OSX
6946 /* Check for platform passed in spawn attr if iOS binary is being spawned */
6947 if (proc_platform(p) == PLATFORM_IOS) {
6948 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6949 if (psa == NULL || psa->psa_platform == 0) {
6950 boolean_t no_sandbox_entitled = FALSE;
6951 #if DEBUG || DEVELOPMENT
6952 /*
6953 * Allow iOS binaries to spawn on internal systems
6954 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
6955 * boot-arg set to true
6956 */
6957 if (unentitled_ios_sim_launch) {
6958 no_sandbox_entitled = TRUE;
6959 } else {
6960 no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
6961 (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
6962 }
6963 #endif /* DEBUG || DEVELOPMENT */
6964 if (!no_sandbox_entitled) {
6965 signature_failure_reason = os_reason_create(OS_REASON_EXEC,
6966 EXEC_EXIT_REASON_WRONG_PLATFORM);
6967 error = EACCES;
6968 goto done;
6969 }
6970 printf("Allowing spawn of iOS binary %s since it has "
6971 "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
6972 "boot-arg set to true\n", p->p_name);
6973 } else if (psa->psa_platform != PLATFORM_IOS) {
6974 /* Simulator binary spawned with wrong platform */
6975 signature_failure_reason = os_reason_create(OS_REASON_EXEC,
6976 EXEC_EXIT_REASON_WRONG_PLATFORM);
6977 error = EACCES;
6978 goto done;
6979 } else {
6980 printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
6981 p->p_name);
6982 }
6983 }
6984 #endif /* XNU_TARGET_OS_OSX */
6985
6986 /* If the code signature came through the image activation path, we skip the
6987 * taskgated / externally attached path. */
6988 if (imgp->ip_csflags & CS_SIGNED) {
6989 error = 0;
6990 goto done;
6991 }
6992
6993 /* The rest of the code is for signatures that either already have been externally
6994 * attached (likely, but not necessarily by a previous run through the taskgated
6995 * path), or that will now be attached by taskgated. */
6996
6997 kr = task_get_task_access_port(p->task, &port);
6998 if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
6999 error = 0;
7000 if (require_success) {
7001 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7002 proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
7003 signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
7004 error = EACCES;
7005 }
7006 goto done;
7007 }
7008
7009 /*
7010 * taskgated returns KERN_SUCCESS if it has completed its work
7011 * and the exec should continue, KERN_FAILURE if the exec should
7012 * fail, or it may error out with different error code in an
7013 * event of mig failure (e.g. process was signalled during the
7014 * rpc call, taskgated died, mig server died etc.).
7015 */
7016
7017 kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
7018 switch (kr) {
7019 case KERN_SUCCESS:
7020 error = 0;
7021 break;
7022 case KERN_FAILURE:
7023 error = EACCES;
7024
7025 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7026 proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
7027 signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
7028 goto done;
7029 default:
7030 error = EACCES;
7031
7032 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7033 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
7034 signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
7035 unexpected_failure = TRUE;
7036 goto done;
7037 }
7038
7039 /* Only do this if exec_resettextvp() did not fail */
7040 if (p->p_textvp != NULLVP) {
7041 csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
7042
7043 if (csb != NULL) {
7044 /* As the enforcement we can do here is very limited, we only allow things that
7045 * are the only reason why this code path still exists:
7046 * Adhoc signed non-platform binaries without special cs_flags and without any
7047 * entitlements (unrestricted ones still pass AMFI). */
7048 if (
7049 /* Revalidate the blob if necessary through bumped generation count. */
7050 (ubc_cs_generation_check(p->p_textvp) == 0 ||
7051 ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
7052 /* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
7053 (csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
7054 /* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
7055 csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
7056 CSSLOT_SIGNATURESLOT,
7057 CSMAGIC_BLOBWRAPPER) == NULL &&
7058 /* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
7059 csb->csb_platform_binary == 0 &&
7060 /* No entitlements, not even unrestricted ones. */
7061 csb->csb_entitlements_blob == NULL &&
7062 csb->csb_der_entitlements_blob == NULL) {
7063 proc_lock(p);
7064 proc_csflags_set(p, CS_SIGNED | CS_VALID);
7065 proc_unlock(p);
7066 } else {
7067 uint8_t cdhash[CS_CDHASH_LEN];
7068 char cdhash_string[CS_CDHASH_STRING_SIZE];
7069 proc_getcdhash(p, cdhash);
7070 cdhash_to_string(cdhash_string, cdhash);
7071 printf("ignoring detached code signature on '%s' with cdhash '%s' "
7072 "because it is invalid, or not a simple adhoc signature.\n",
7073 p->p_name, cdhash_string);
7074 }
7075 }
7076 }
7077
7078 done:
7079 if (0 == error) {
7080 /* The process's code signature related properties are
7081 * fully set up, so this is an opportune moment to log
7082 * platform binary execution, if desired. */
7083 if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
7084 uint8_t cdhash[CS_CDHASH_LEN];
7085 char cdhash_string[CS_CDHASH_STRING_SIZE];
7086 proc_getcdhash(p, cdhash);
7087 cdhash_to_string(cdhash_string, cdhash);
7088
7089 os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
7090 "'%s' with cdhash %s\n", p->p_name, cdhash_string);
7091 }
7092 } else {
7093 if (!unexpected_failure) {
7094 proc_csflags_set(p, CS_KILLED);
7095 }
7096 /* make very sure execution fails */
7097 if (vfexec || spawn) {
7098 assert(signature_failure_reason != OS_REASON_NULL);
7099 psignal_vfork_with_reason(p, p->task, imgp->ip_new_thread,
7100 SIGKILL, signature_failure_reason);
7101 signature_failure_reason = OS_REASON_NULL;
7102 error = 0;
7103 } else {
7104 assert(signature_failure_reason != OS_REASON_NULL);
7105 psignal_with_reason(p, SIGKILL, signature_failure_reason);
7106 signature_failure_reason = OS_REASON_NULL;
7107 }
7108 }
7109
7110 if (port != IPC_PORT_NULL) {
7111 ipc_port_release_send(port);
7112 }
7113
7114 /* If we hit this, we likely would have leaked an exit reason */
7115 assert(signature_failure_reason == OS_REASON_NULL);
7116 return error;
7117 }
7118
7119 /*
7120 * Typically as soon as we start executing this process, the
7121 * first instruction will trigger a VM fault to bring the text
7122 * pages (as executable) into the address space, followed soon
7123 * thereafter by dyld data structures (for dynamic executable).
7124 * To optimize this, as well as improve support for hardware
7125 * debuggers that can only access resident pages present
7126 * in the process' page tables, we prefault some pages if
7127 * possible. Errors are non-fatal.
7128 */
7129 #ifndef PREVENT_CALLER_STACK_USE
7130 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
7131 #endif
7132 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(proc_t p __unused,struct image_params * imgp,load_result_t * load_result)7133 exec_prefault_data(proc_t p __unused, struct image_params *imgp, load_result_t *load_result)
7134 {
7135 int ret;
7136 size_t expected_all_image_infos_size;
7137 kern_return_t kr;
7138
7139 /*
7140 * Prefault executable or dyld entry point.
7141 */
7142 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7143 DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
7144 }
7145 kr = vm_fault(current_map(),
7146 vm_map_trunc_page(load_result->entry_point,
7147 vm_map_page_mask(current_map())),
7148 VM_PROT_READ | VM_PROT_EXECUTE,
7149 FALSE, VM_KERN_MEMORY_NONE,
7150 THREAD_UNINT, NULL, 0);
7151 if (kr != KERN_SUCCESS) {
7152 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);
7153 }
7154
7155 if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7156 expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
7157 } else {
7158 expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
7159 }
7160
7161 /* Decode dyld anchor structure from <mach-o/dyld_images.h> */
7162 if (load_result->dynlinker &&
7163 load_result->all_image_info_addr &&
7164 load_result->all_image_info_size >= expected_all_image_infos_size) {
7165 union {
7166 struct user64_dyld_all_image_infos infos64;
7167 struct user32_dyld_all_image_infos infos32;
7168 } all_image_infos;
7169
7170 /*
7171 * Pre-fault to avoid copyin() going through the trap handler
7172 * and recovery path.
7173 */
7174 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7175 DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
7176 }
7177 kr = vm_fault(current_map(),
7178 vm_map_trunc_page(load_result->all_image_info_addr,
7179 vm_map_page_mask(current_map())),
7180 VM_PROT_READ | VM_PROT_WRITE,
7181 FALSE, VM_KERN_MEMORY_NONE,
7182 THREAD_UNINT, NULL, 0);
7183 if (kr != KERN_SUCCESS) {
7184 // 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);
7185 }
7186 if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
7187 /* all_image_infos straddles a page */
7188 kr = vm_fault(current_map(),
7189 vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
7190 vm_map_page_mask(current_map())),
7191 VM_PROT_READ | VM_PROT_WRITE,
7192 FALSE, VM_KERN_MEMORY_NONE,
7193 THREAD_UNINT, NULL, 0);
7194 if (kr != KERN_SUCCESS) {
7195 // 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);
7196 }
7197 }
7198
7199 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7200 DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
7201 }
7202 ret = copyin((user_addr_t)load_result->all_image_info_addr,
7203 &all_image_infos,
7204 expected_all_image_infos_size);
7205 if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
7206 user_addr_t notification_address;
7207 user_addr_t dyld_image_address;
7208 user_addr_t dyld_version_address;
7209 user_addr_t dyld_all_image_infos_address;
7210 user_addr_t dyld_slide_amount;
7211
7212 if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7213 notification_address = (user_addr_t)all_image_infos.infos64.notification;
7214 dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
7215 dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
7216 dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
7217 } else {
7218 notification_address = all_image_infos.infos32.notification;
7219 dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
7220 dyld_version_address = all_image_infos.infos32.dyldVersion;
7221 dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
7222 }
7223
7224 /*
7225 * dyld statically sets up the all_image_infos in its Mach-O
7226 * binary at static link time, with pointers relative to its default
7227 * load address. Since ASLR might slide dyld before its first
7228 * instruction is executed, "dyld_slide_amount" tells us how far
7229 * dyld was loaded compared to its default expected load address.
7230 * All other pointers into dyld's image should be adjusted by this
7231 * amount. At some point later, dyld will fix up pointers to take
7232 * into account the slide, at which point the all_image_infos_address
7233 * field in the structure will match the runtime load address, and
7234 * "dyld_slide_amount" will be 0, if we were to consult it again.
7235 */
7236
7237 dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
7238
7239 #if 0
7240 kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
7241 (uint64_t)load_result->all_image_info_addr,
7242 all_image_infos.infos32.version,
7243 (uint64_t)notification_address,
7244 (uint64_t)dyld_image_address,
7245 (uint64_t)dyld_version_address,
7246 (uint64_t)dyld_all_image_infos_address);
7247 #endif
7248
7249 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7250 DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
7251 }
7252 kr = vm_fault(current_map(),
7253 vm_map_trunc_page(notification_address + dyld_slide_amount,
7254 vm_map_page_mask(current_map())),
7255 VM_PROT_READ | VM_PROT_EXECUTE,
7256 FALSE, VM_KERN_MEMORY_NONE,
7257 THREAD_UNINT, NULL, 0);
7258 if (kr != KERN_SUCCESS) {
7259 // 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);
7260 }
7261 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7262 DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
7263 }
7264 kr = vm_fault(current_map(),
7265 vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
7266 vm_map_page_mask(current_map())),
7267 VM_PROT_READ | VM_PROT_EXECUTE,
7268 FALSE, VM_KERN_MEMORY_NONE,
7269 THREAD_UNINT, NULL, 0);
7270 if (kr != KERN_SUCCESS) {
7271 // 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);
7272 }
7273 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7274 DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
7275 }
7276 kr = vm_fault(current_map(),
7277 vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
7278 vm_map_page_mask(current_map())),
7279 VM_PROT_READ,
7280 FALSE, VM_KERN_MEMORY_NONE,
7281 THREAD_UNINT, NULL, 0);
7282 if (kr != KERN_SUCCESS) {
7283 // 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);
7284 }
7285 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7286 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);
7287 }
7288 kr = vm_fault(current_map(),
7289 vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
7290 vm_map_page_mask(current_map())),
7291 VM_PROT_READ | VM_PROT_WRITE,
7292 FALSE, VM_KERN_MEMORY_NONE,
7293 THREAD_UNINT, NULL, 0);
7294 if (kr != KERN_SUCCESS) {
7295 // 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);
7296 }
7297 }
7298 }
7299 }
7300
7301 static int
7302 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
7303 {
7304 #pragma unused(oidp, arg2, req)
7305 int changed;
7306 errno_t error;
7307 uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
7308
7309 error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
7310 if (error) {
7311 return error;
7312 }
7313
7314 if (changed) {
7315 os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
7316 }
7317
7318 return 0;
7319 }
7320
7321 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
7322
7323