1 /*
2 * Copyright (c) 2000-2020 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30 * Mach Operating System
31 * Copyright (c) 1987 Carnegie-Mellon University
32 * All rights reserved. The CMU software License Agreement specifies
33 * the terms and conditions for use and redistribution.
34 */
35
36 /*-
37 * Copyright (c) 1982, 1986, 1991, 1993
38 * The Regents of the University of California. All rights reserved.
39 * (c) UNIX System Laboratories, Inc.
40 * All or some portions of this file are derived from material licensed
41 * to the University of California by American Telephone and Telegraph
42 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
43 * the permission of UNIX System Laboratories, Inc.
44 *
45 * Redistribution and use in source and binary forms, with or without
46 * modification, are permitted provided that the following conditions
47 * are met:
48 * 1. Redistributions of source code must retain the above copyright
49 * notice, this list of conditions and the following disclaimer.
50 * 2. Redistributions in binary form must reproduce the above copyright
51 * notice, this list of conditions and the following disclaimer in the
52 * documentation and/or other materials provided with the distribution.
53 * 3. All advertising materials mentioning features or use of this software
54 * must display the following acknowledgement:
55 * This product includes software developed by the University of
56 * California, Berkeley and its contributors.
57 * 4. Neither the name of the University nor the names of its contributors
58 * may be used to endorse or promote products derived from this software
59 * without specific prior written permission.
60 *
61 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71 * SUCH DAMAGE.
72 *
73 * from: @(#)kern_exec.c 8.1 (Berkeley) 6/10/93
74 */
75 /*
76 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
77 * support for mandatory and extensible security protections. This notice
78 * is included in support of clause 2.2 (b) of the Apple Public License,
79 * Version 2.0.
80 */
81 #include <machine/reg.h>
82 #include <machine/cpu_capabilities.h>
83
84 #include <sys/cdefs.h>
85 #include <sys/param.h>
86 #include <sys/systm.h>
87 #include <sys/filedesc.h>
88 #include <sys/kernel.h>
89 #include <sys/proc_internal.h>
90 #include <sys/kauth.h>
91 #include <sys/user.h>
92 #include <sys/socketvar.h>
93 #include <sys/malloc.h>
94 #include <sys/namei.h>
95 #include <sys/mount_internal.h>
96 #include <sys/vnode_internal.h>
97 #include <sys/file_internal.h>
98 #include <sys/stat.h>
99 #include <sys/uio_internal.h>
100 #include <sys/acct.h>
101 #include <sys/exec.h>
102 #include <sys/kdebug.h>
103 #include <sys/signal.h>
104 #include <sys/aio_kern.h>
105 #include <sys/sysproto.h>
106 #include <sys/sysctl.h>
107 #include <sys/persona.h>
108 #include <sys/reason.h>
109 #if SYSV_SHM
110 #include <sys/shm_internal.h> /* shmexec() */
111 #endif
112 #include <sys/ubc_internal.h> /* ubc_map() */
113 #include <sys/spawn.h>
114 #include <sys/spawn_internal.h>
115 #include <sys/process_policy.h>
116 #include <sys/codesign.h>
117 #include <sys/random.h>
118 #include <crypto/sha1.h>
119
120 #include <libkern/libkern.h>
121 #include <libkern/crypto/sha2.h>
122 #include <security/audit/audit.h>
123
124 #include <ipc/ipc_types.h>
125
126 #include <mach/mach_param.h>
127 #include <mach/mach_types.h>
128 #include <mach/port.h>
129 #include <mach/task.h>
130 #include <mach/task_access.h>
131 #include <mach/thread_act.h>
132 #include <mach/vm_map.h>
133 #include <mach/mach_vm.h>
134 #include <mach/vm_param.h>
135 #include <mach_debug/mach_debug_types.h>
136
137 #include <kern/sched_prim.h> /* thread_wakeup() */
138 #include <kern/affinity.h>
139 #include <kern/assert.h>
140 #include <kern/task.h>
141 #include <kern/thread.h>
142 #include <kern/coalition.h>
143 #include <kern/policy_internal.h>
144 #include <kern/kalloc.h>
145 #include <kern/zalloc.h> /* zone_userspace_reboot_checks() */
146
147 #include <os/log.h>
148
149 #if CONFIG_MACF
150 #include <security/mac_framework.h>
151 #include <security/mac_mach_internal.h>
152 #endif
153
154 #if CONFIG_AUDIT
155 #include <bsm/audit_kevents.h>
156 #endif
157
158 #if CONFIG_ARCADE
159 #include <kern/arcade.h>
160 #endif
161
162 #include <vm/vm_map_xnu.h>
163 #include <vm/vm_kern_xnu.h>
164 #include <vm/vm_protos.h>
165 #include <vm/vm_fault.h>
166 #include <vm/vm_pageout_xnu.h>
167 #include <vm/pmap.h>
168 #include <vm/vm_reclaim_xnu.h>
169
170 #include <kdp/kdp_dyld.h>
171
172 #include <machine/machine_routines.h>
173 #include <machine/pal_routines.h>
174
175 #include <pexpert/pexpert.h>
176
177 #if CONFIG_MEMORYSTATUS
178 #include <sys/kern_memorystatus.h>
179 #endif
180
181 #include <IOKit/IOBSD.h>
182
183 #include "kern_exec_internal.h"
184
185 #include <CodeSignature/Entitlements.h>
186
187 #include <mach/exclaves.h>
188
189
190 extern boolean_t vm_darkwake_mode;
191
192 /* enable crash reports on various exec failures */
193 static TUNABLE(bool, bootarg_execfailurereports, "execfailurecrashes", false);
194
195 #if XNU_TARGET_OS_OSX
196 #if __has_feature(ptrauth_calls)
197 static TUNABLE(bool, bootarg_arm64e_preview_abi, "-arm64e_preview_abi", false);
198 #endif /* __has_feature(ptrauth_calls) */
199
200 #if DEBUG || DEVELOPMENT
201 static TUNABLE(bool, unentitled_ios_sim_launch, "unentitled_ios_sim_launch", false);
202 #endif /* DEBUG || DEVELOPMENT */
203 #endif /* XNU_TARGET_OS_OSX */
204
205 #if CONFIG_DTRACE
206 /* Do not include dtrace.h, it redefines kmem_[alloc/free] */
207 extern void dtrace_proc_exec(proc_t);
208 extern void (*dtrace_proc_waitfor_exec_ptr)(proc_t);
209
210 /*
211 * Since dtrace_proc_waitfor_exec_ptr can be added/removed in dtrace_subr.c,
212 * we will store its value before actually calling it.
213 */
214 static void (*dtrace_proc_waitfor_hook)(proc_t) = NULL;
215
216 #include <sys/dtrace_ptss.h>
217 #endif
218
219 #if __has_feature(ptrauth_calls)
220 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_per_team_id,
221 "vm_shared_region_per_team_id", 1);
222 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_by_entitlement,
223 "vm_shared_region_by_entitlement", 1);
224
225 /* Upon userland request, reslide the shared cache. */
226 static TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_aslr,
227 "vm_shared_region_reslide_aslr",
228 #if CONFIG_RESLIDE_SHARED_CACHE
229 1
230 #else
231 0
232 #endif /* CONFIG_RESLIDE_SHARED_CACHE */
233 );
234
235 /*
236 * Flag to control what processes should get shared cache randomize resliding
237 * after a fault in the shared cache region:
238 *
239 * 0 - all processes get a new randomized slide
240 * 1 - only platform processes get a new randomized slide
241 */
242 TUNABLE_DEV_WRITEABLE(int, vm_shared_region_reslide_restrict,
243 "vm_shared_region_reslide_restrict", 1);
244
245 #if DEVELOPMENT || DEBUG
246 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_per_team_id,
247 CTLFLAG_RW, &vm_shared_region_per_team_id, 0, "");
248 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_by_entitlement,
249 CTLFLAG_RW, &vm_shared_region_by_entitlement, 0, "");
250 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_restrict,
251 CTLFLAG_RW, &vm_shared_region_reslide_restrict, 0, "");
252 SYSCTL_INT(_vm, OID_AUTO, vm_shared_region_reslide_aslr,
253 CTLFLAG_RW, &vm_shared_region_reslide_aslr, 0, "");
254 #endif
255 #endif /* __has_feature(ptrauth_calls) */
256
257 #if DEVELOPMENT || DEBUG
258 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", true);
259 #else
260 static TUNABLE(bool, enable_dext_coredumps_on_panic, "dext_panic_coredump", false);
261 #endif
262 extern kern_return_t kern_register_userspace_coredump(task_t task, const char * name);
263 #define USERSPACE_COREDUMP_PANIC_ENTITLEMENT "com.apple.private.enable-coredump-on-panic"
264 #define USERSPACE_COREDUMP_PANIC_SEED_ENTITLEMENT \
265 "com.apple.private.enable-coredump-on-panic-seed-privacy-approved"
266
267 extern void proc_apply_task_networkbg_internal(proc_t, thread_t);
268 extern void task_set_did_exec_flag(task_t task);
269 extern void task_clear_exec_copy_flag(task_t task);
270 proc_t proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task,
271 task_t new_task, struct image_params *imgp, void **inherit);
272 boolean_t task_is_active(task_t);
273 boolean_t thread_is_active(thread_t thread);
274 void thread_copy_resource_info(thread_t dst_thread, thread_t src_thread);
275 void *ipc_importance_exec_switch_task(task_t old_task, task_t new_task);
276 extern void ipc_importance_release(void *elem);
277 extern boolean_t task_has_watchports(task_t task);
278 extern void task_set_no_smt(task_t task);
279 #if defined(HAS_APPLE_PAC)
280 char *task_get_vm_shared_region_id_and_jop_pid(task_t task, uint64_t *jop_pid);
281 #endif
282 task_t convert_port_to_task(ipc_port_t port);
283
284 #if CONFIG_EXCLAVES
285 int task_add_conclave(task_t task, void *vnode, int64_t off, const char *task_conclave_id);
286 kern_return_t task_inherit_conclave(task_t old_task, task_t new_task, void *vnode, int64_t off);
287 #endif /* CONFIG_EXCLAVES */
288
289
290 /*
291 * Mach things for which prototypes are unavailable from Mach headers
292 */
293 #define IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND 0x1
294 void ipc_task_enable(
295 task_t task);
296 void ipc_task_reset(
297 task_t task);
298 void ipc_thread_reset(
299 thread_t thread);
300 kern_return_t ipc_object_copyin(
301 ipc_space_t space,
302 mach_port_name_t name,
303 mach_msg_type_name_t msgt_name,
304 ipc_object_t *objectp,
305 mach_port_context_t context,
306 mach_msg_guard_flags_t *guard_flags,
307 uint32_t kmsg_flags);
308 void ipc_port_release_send(ipc_port_t);
309
310 #if DEVELOPMENT || DEBUG
311 void task_importance_update_owner_info(task_t);
312 #endif
313
314 extern struct savearea *get_user_regs(thread_t);
315
316 __attribute__((noinline)) int __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid);
317
318 #include <kern/thread.h>
319 #include <kern/task.h>
320 #include <kern/ast.h>
321 #include <kern/mach_loader.h>
322 #include <kern/mach_fat.h>
323 #include <mach-o/fat.h>
324 #include <mach-o/loader.h>
325 #include <machine/vmparam.h>
326 #include <sys/imgact.h>
327
328 #include <sys/sdt.h>
329
330
331 /*
332 * EAI_ITERLIMIT The maximum number of times to iterate an image
333 * activator in exec_activate_image() before treating
334 * it as malformed/corrupt.
335 */
336 #define EAI_ITERLIMIT 3
337
338 /*
339 * For #! interpreter parsing
340 */
341 #define IS_WHITESPACE(ch) ((ch == ' ') || (ch == '\t'))
342 #define IS_EOL(ch) ((ch == '#') || (ch == '\n'))
343
344 extern vm_map_t bsd_pageable_map;
345 extern const struct fileops vnops;
346 extern int nextpidversion;
347
348
349 #define USER_ADDR_ALIGN(addr, val) \
350 ( ( (user_addr_t)(addr) + (val) - 1) \
351 & ~((val) - 1) )
352
353 /*
354 * For subsystem root support
355 */
356 #define SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT "com.apple.private.spawn-subsystem-root"
357
358 /*
359 * Allow setting p_crash_behavior to trigger panic on crash
360 */
361 #define SPAWN_SET_PANIC_CRASH_BEHAVIOR "com.apple.private.spawn-panic-crash-behavior"
362
363 /* Platform Code Exec Logging */
364 static int platform_exec_logging = 0;
365
366 SYSCTL_DECL(_security_mac);
367
368 SYSCTL_INT(_security_mac, OID_AUTO, platform_exec_logging, CTLFLAG_RW, &platform_exec_logging, 0,
369 "log cdhashes for all platform binary executions");
370
371 static os_log_t peLog = OS_LOG_DEFAULT;
372
373 struct exception_port_action_t {
374 ipc_port_t port;
375 _ps_port_action_t *port_action;
376 };
377
378 struct exec_port_actions {
379 uint32_t exception_port_count;
380 uint32_t portwatch_count;
381 uint32_t registered_count;
382 struct exception_port_action_t *excport_array;
383 ipc_port_t *portwatch_array;
384 ipc_port_t registered_array[TASK_PORT_REGISTER_MAX];
385 };
386
387 struct image_params; /* Forward */
388 static int exec_activate_image(struct image_params *imgp);
389 static int exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp);
390 static int load_return_to_errno(load_return_t lrtn);
391 static int execargs_alloc(struct image_params *imgp);
392 static int execargs_free(struct image_params *imgp);
393 static int exec_check_permissions(struct image_params *imgp);
394 static int exec_extract_strings(struct image_params *imgp);
395 static int exec_add_apple_strings(struct image_params *imgp, const load_result_t *load_result);
396 static int exec_handle_sugid(struct image_params *imgp);
397 static int sugid_scripts = 0;
398 SYSCTL_INT(_kern, OID_AUTO, sugid_scripts, CTLFLAG_RW | CTLFLAG_LOCKED, &sugid_scripts, 0, "");
399 static kern_return_t create_unix_stack(vm_map_t map, load_result_t* load_result, proc_t p);
400 static int copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size);
401 static void exec_resettextvp(proc_t, struct image_params *);
402 static int process_signature(proc_t, struct image_params *);
403 static void exec_prefault_data(proc_t, struct image_params *, load_result_t *);
404 static errno_t exec_handle_port_actions(struct image_params *imgp,
405 struct exec_port_actions *port_actions);
406 static errno_t exec_handle_exception_port_actions(const struct image_params *imgp,
407 const struct exec_port_actions *port_actions);
408 static errno_t exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
409 task_role_t psa_darwin_role, struct exec_port_actions *port_actions);
410 static void exec_port_actions_destroy(struct exec_port_actions *port_actions);
411
412 /*
413 * exec_add_user_string
414 *
415 * Add the requested string to the string space area.
416 *
417 * Parameters; struct image_params * image parameter block
418 * user_addr_t string to add to strings area
419 * int segment from which string comes
420 * boolean_t TRUE if string contributes to NCARGS
421 *
422 * Returns: 0 Success
423 * !0 Failure errno from copyinstr()
424 *
425 * Implicit returns:
426 * (imgp->ip_strendp) updated location of next add, if any
427 * (imgp->ip_strspace) updated byte count of space remaining
428 * (imgp->ip_argspace) updated byte count of space in NCARGS
429 */
430 __attribute__((noinline))
431 static int
exec_add_user_string(struct image_params * imgp,user_addr_t str,int seg,boolean_t is_ncargs)432 exec_add_user_string(struct image_params *imgp, user_addr_t str, int seg, boolean_t is_ncargs)
433 {
434 int error = 0;
435
436 do {
437 size_t len = 0;
438 int space;
439
440 if (is_ncargs) {
441 space = imgp->ip_argspace; /* by definition smaller than ip_strspace */
442 } else {
443 space = imgp->ip_strspace;
444 }
445
446 if (space <= 0) {
447 error = E2BIG;
448 break;
449 }
450
451 if (!UIO_SEG_IS_USER_SPACE(seg)) {
452 char *kstr = CAST_DOWN(char *, str); /* SAFE */
453 error = copystr(kstr, imgp->ip_strendp, space, &len);
454 } else {
455 error = copyinstr(str, imgp->ip_strendp, space, &len);
456 }
457
458 imgp->ip_strendp += len;
459 imgp->ip_strspace -= len;
460 if (is_ncargs) {
461 imgp->ip_argspace -= len;
462 }
463 } while (error == ENAMETOOLONG);
464
465 return error;
466 }
467
468 /*
469 * dyld is now passed the executable path as a getenv-like variable
470 * in the same fashion as the stack_guard and malloc_entropy keys.
471 */
472 #define EXECUTABLE_KEY "executable_path="
473
474 /*
475 * exec_save_path
476 *
477 * To support new app package launching for Mac OS X, the dyld needs the
478 * first argument to execve() stored on the user stack.
479 *
480 * Save the executable path name at the bottom of the strings area and set
481 * the argument vector pointer to the location following that to indicate
482 * the start of the argument and environment tuples, setting the remaining
483 * string space count to the size of the string area minus the path length.
484 *
485 * Parameters; struct image_params * image parameter block
486 * char * path used to invoke program
487 * int segment from which path comes
488 *
489 * Returns: int 0 Success
490 * EFAULT Bad address
491 * copy[in]str:EFAULT Bad address
492 * copy[in]str:ENAMETOOLONG Filename too long
493 *
494 * Implicit returns:
495 * (imgp->ip_strings) saved path
496 * (imgp->ip_strspace) space remaining in ip_strings
497 * (imgp->ip_strendp) start of remaining copy area
498 * (imgp->ip_argspace) space remaining of NCARGS
499 * (imgp->ip_applec) Initial applev[0]
500 *
501 * Note: We have to do this before the initial namei() since in the
502 * path contains symbolic links, namei() will overwrite the
503 * original path buffer contents. If the last symbolic link
504 * resolved was a relative pathname, we would lose the original
505 * "path", which could be an absolute pathname. This might be
506 * unacceptable for dyld.
507 */
508 static int
exec_save_path(struct image_params * imgp,user_addr_t path,int seg,const char ** excpath)509 exec_save_path(struct image_params *imgp, user_addr_t path, int seg, const char **excpath)
510 {
511 int error;
512 size_t len;
513 char *kpath;
514
515 // imgp->ip_strings can come out of a cache, so we need to obliterate the
516 // old path.
517 memset(imgp->ip_strings, '\0', strlen(EXECUTABLE_KEY) + MAXPATHLEN);
518
519 len = MIN(MAXPATHLEN, imgp->ip_strspace);
520
521 switch (seg) {
522 case UIO_USERSPACE32:
523 case UIO_USERSPACE64: /* Same for copyin()... */
524 error = copyinstr(path, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
525 break;
526 case UIO_SYSSPACE:
527 kpath = CAST_DOWN(char *, path); /* SAFE */
528 error = copystr(kpath, imgp->ip_strings + strlen(EXECUTABLE_KEY), len, &len);
529 break;
530 default:
531 error = EFAULT;
532 break;
533 }
534
535 if (!error) {
536 bcopy(EXECUTABLE_KEY, imgp->ip_strings, strlen(EXECUTABLE_KEY));
537 len += strlen(EXECUTABLE_KEY);
538
539 imgp->ip_strendp += len;
540 imgp->ip_strspace -= len;
541
542 if (excpath) {
543 *excpath = imgp->ip_strings + strlen(EXECUTABLE_KEY);
544 }
545 }
546
547 return error;
548 }
549
550 /*
551 * exec_reset_save_path
552 *
553 * If we detect a shell script, we need to reset the string area
554 * state so that the interpreter can be saved onto the stack.
555 *
556 * Parameters; struct image_params * image parameter block
557 *
558 * Returns: int 0 Success
559 *
560 * Implicit returns:
561 * (imgp->ip_strings) saved path
562 * (imgp->ip_strspace) space remaining in ip_strings
563 * (imgp->ip_strendp) start of remaining copy area
564 * (imgp->ip_argspace) space remaining of NCARGS
565 *
566 */
567 static int
exec_reset_save_path(struct image_params * imgp)568 exec_reset_save_path(struct image_params *imgp)
569 {
570 imgp->ip_strendp = imgp->ip_strings;
571 imgp->ip_argspace = NCARGS;
572 imgp->ip_strspace = (NCARGS + PAGE_SIZE);
573
574 return 0;
575 }
576
577 /*
578 * exec_shell_imgact
579 *
580 * Image activator for interpreter scripts. If the image begins with
581 * the characters "#!", then it is an interpreter script. Verify the
582 * length of the script line indicating the interpreter is not in
583 * excess of the maximum allowed size. If this is the case, then
584 * break out the arguments, if any, which are separated by white
585 * space, and copy them into the argument save area as if they were
586 * provided on the command line before all other arguments. The line
587 * ends when we encounter a comment character ('#') or newline.
588 *
589 * Parameters; struct image_params * image parameter block
590 *
591 * Returns: -1 not an interpreter (keep looking)
592 * -3 Success: interpreter: relookup
593 * >0 Failure: interpreter: error number
594 *
595 * A return value other than -1 indicates subsequent image activators should
596 * not be given the opportunity to attempt to activate the image.
597 */
598 static int
exec_shell_imgact(struct image_params * imgp)599 exec_shell_imgact(struct image_params *imgp)
600 {
601 char *vdata = imgp->ip_vdata;
602 char *ihp;
603 char *line_startp, *line_endp;
604 char *interp;
605
606 /*
607 * Make sure it's a shell script. If we've already redirected
608 * from an interpreted file once, don't do it again.
609 */
610 if (vdata[0] != '#' ||
611 vdata[1] != '!' ||
612 (imgp->ip_flags & IMGPF_INTERPRET) != 0) {
613 return -1;
614 }
615
616 if (imgp->ip_origcputype != 0) {
617 /* Fat header previously matched, don't allow shell script inside */
618 return -1;
619 }
620
621 imgp->ip_flags |= IMGPF_INTERPRET;
622 imgp->ip_interp_sugid_fd = -1;
623 imgp->ip_interp_buffer[0] = '\0';
624
625 /* Check to see if SUGID scripts are permitted. If they aren't then
626 * clear the SUGID bits.
627 * imgp->ip_vattr is known to be valid.
628 */
629 if (sugid_scripts == 0) {
630 imgp->ip_origvattr->va_mode &= ~(VSUID | VSGID);
631 }
632
633 /* Try to find the first non-whitespace character */
634 for (ihp = &vdata[2]; ihp < &vdata[IMG_SHSIZE]; ihp++) {
635 if (IS_EOL(*ihp)) {
636 /* Did not find interpreter, "#!\n" */
637 return ENOEXEC;
638 } else if (IS_WHITESPACE(*ihp)) {
639 /* Whitespace, like "#! /bin/sh\n", keep going. */
640 } else {
641 /* Found start of interpreter */
642 break;
643 }
644 }
645
646 if (ihp == &vdata[IMG_SHSIZE]) {
647 /* All whitespace, like "#! " */
648 return ENOEXEC;
649 }
650
651 line_startp = ihp;
652
653 /* Try to find the end of the interpreter+args string */
654 for (; ihp < &vdata[IMG_SHSIZE]; ihp++) {
655 if (IS_EOL(*ihp)) {
656 /* Got it */
657 break;
658 } else {
659 /* Still part of interpreter or args */
660 }
661 }
662
663 if (ihp == &vdata[IMG_SHSIZE]) {
664 /* A long line, like "#! blah blah blah" without end */
665 return ENOEXEC;
666 }
667
668 /* Backtrack until we find the last non-whitespace */
669 while (IS_EOL(*ihp) || IS_WHITESPACE(*ihp)) {
670 ihp--;
671 }
672
673 /* The character after the last non-whitespace is our logical end of line */
674 line_endp = ihp + 1;
675
676 /*
677 * Now we have pointers to the usable part of:
678 *
679 * "#! /usr/bin/int first second third \n"
680 * ^ line_startp ^ line_endp
681 */
682
683 /* copy the interpreter name */
684 interp = imgp->ip_interp_buffer;
685 for (ihp = line_startp; (ihp < line_endp) && !IS_WHITESPACE(*ihp); ihp++) {
686 *interp++ = *ihp;
687 }
688 *interp = '\0';
689
690 exec_reset_save_path(imgp);
691 exec_save_path(imgp, CAST_USER_ADDR_T(imgp->ip_interp_buffer),
692 UIO_SYSSPACE, NULL);
693
694 /* Copy the entire interpreter + args for later processing into argv[] */
695 interp = imgp->ip_interp_buffer;
696 for (ihp = line_startp; (ihp < line_endp); ihp++) {
697 *interp++ = *ihp;
698 }
699 *interp = '\0';
700
701 #if CONFIG_SETUID
702 /*
703 * If we have an SUID or SGID script, create a file descriptor
704 * from the vnode and pass /dev/fd/%d instead of the actual
705 * path name so that the script does not get opened twice
706 */
707 if (imgp->ip_origvattr->va_mode & (VSUID | VSGID)) {
708 proc_t p;
709 struct fileproc *fp;
710 int fd;
711 int error;
712
713 p = vfs_context_proc(imgp->ip_vfs_context);
714 error = falloc_exec(p, imgp->ip_vfs_context, &fp, &fd);
715 if (error) {
716 return error;
717 }
718
719 fp->fp_glob->fg_flag = FREAD;
720 fp->fp_glob->fg_ops = &vnops;
721 fp_set_data(fp, imgp->ip_vp);
722
723 proc_fdlock(p);
724 procfdtbl_releasefd(p, fd, NULL);
725 fp_drop(p, fd, fp, 1);
726 proc_fdunlock(p);
727 vnode_ref(imgp->ip_vp);
728
729 imgp->ip_interp_sugid_fd = fd;
730 }
731 #endif /* CONFIG_SETUID */
732
733 return -3;
734 }
735
736
737
738 /*
739 * exec_fat_imgact
740 *
741 * Image activator for fat 1.0 binaries. If the binary is fat, then we
742 * need to select an image from it internally, and make that the image
743 * we are going to attempt to execute. At present, this consists of
744 * reloading the first page for the image with a first page from the
745 * offset location indicated by the fat header.
746 *
747 * Parameters; struct image_params * image parameter block
748 *
749 * Returns: -1 not a fat binary (keep looking)
750 * -2 Success: encapsulated binary: reread
751 * >0 Failure: error number
752 *
753 * Important: This image activator is byte order neutral.
754 *
755 * Note: A return value other than -1 indicates subsequent image
756 * activators should not be given the opportunity to attempt
757 * to activate the image.
758 *
759 * If we find an encapsulated binary, we make no assertions
760 * about its validity; instead, we leave that up to a rescan
761 * for an activator to claim it, and, if it is claimed by one,
762 * that activator is responsible for determining validity.
763 */
764 static int
exec_fat_imgact(struct image_params * imgp)765 exec_fat_imgact(struct image_params *imgp)
766 {
767 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
768 kauth_cred_t cred = kauth_cred_proc_ref(p);
769 struct fat_header *fat_header = (struct fat_header *)imgp->ip_vdata;
770 struct _posix_spawnattr *psa = NULL;
771 struct fat_arch fat_arch;
772 int resid, error;
773 load_return_t lret;
774
775 if (imgp->ip_origcputype != 0) {
776 /* Fat header previously matched, don't allow another fat file inside */
777 error = -1; /* not claimed */
778 goto bad;
779 }
780
781 /* Make sure it's a fat binary */
782 if (OSSwapBigToHostInt32(fat_header->magic) != FAT_MAGIC) {
783 error = -1; /* not claimed */
784 goto bad;
785 }
786
787 /* imgp->ip_vdata has PAGE_SIZE, zerofilled if the file is smaller */
788 lret = fatfile_validate_fatarches((vm_offset_t)fat_header, PAGE_SIZE,
789 (off_t)imgp->ip_vattr->va_data_size);
790 if (lret != LOAD_SUCCESS) {
791 error = load_return_to_errno(lret);
792 goto bad;
793 }
794
795 /* If posix_spawn binprefs exist, respect those prefs. */
796 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
797 if (psa != NULL && psa->psa_binprefs[0] != 0) {
798 uint32_t pr = 0;
799
800 /* Check each preference listed against all arches in header */
801 for (pr = 0; pr < NBINPREFS; pr++) {
802 cpu_type_t pref = psa->psa_binprefs[pr];
803 cpu_type_t subpref = psa->psa_subcpuprefs[pr];
804
805 if (pref == 0) {
806 /* No suitable arch in the pref list */
807 error = EBADARCH;
808 goto bad;
809 }
810
811 if (pref == CPU_TYPE_ANY) {
812 /* Fall through to regular grading */
813 goto regular_grading;
814 }
815
816 lret = fatfile_getbestarch_for_cputype(pref,
817 subpref,
818 (vm_offset_t)fat_header,
819 PAGE_SIZE,
820 imgp,
821 &fat_arch);
822 if (lret == LOAD_SUCCESS) {
823 goto use_arch;
824 }
825 }
826
827 /* Requested binary preference was not honored */
828 error = EBADEXEC;
829 goto bad;
830 }
831
832 regular_grading:
833 /* Look up our preferred architecture in the fat file. */
834 lret = fatfile_getbestarch((vm_offset_t)fat_header,
835 PAGE_SIZE,
836 imgp,
837 &fat_arch,
838 (p->p_flag & P_AFFINITY) != 0);
839 if (lret != LOAD_SUCCESS) {
840 error = load_return_to_errno(lret);
841 goto bad;
842 }
843
844 use_arch:
845 /* Read the Mach-O header out of fat_arch */
846 error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata,
847 PAGE_SIZE, fat_arch.offset,
848 UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
849 cred, &resid, p);
850 if (error) {
851 if (error == ERESTART) {
852 error = EINTR;
853 }
854 goto bad;
855 }
856
857 if (resid) {
858 memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
859 }
860
861 /* Success. Indicate we have identified an encapsulated binary */
862 error = -2;
863 imgp->ip_arch_offset = (user_size_t)fat_arch.offset;
864 imgp->ip_arch_size = (user_size_t)fat_arch.size;
865 imgp->ip_origcputype = fat_arch.cputype;
866 imgp->ip_origcpusubtype = fat_arch.cpusubtype;
867
868 bad:
869 kauth_cred_unref(&cred);
870 return error;
871 }
872
873 static int
activate_exec_state(task_t task,proc_t p,thread_t thread,load_result_t * result)874 activate_exec_state(task_t task, proc_t p, thread_t thread, load_result_t *result)
875 {
876 int ret;
877
878 (void)task_set_dyld_info(task, MACH_VM_MIN_ADDRESS, 0, false);
879 task_set_64bit(task, result->is_64bit_addr, result->is_64bit_data);
880 if (result->is_64bit_addr) {
881 OSBitOrAtomic(P_LP64, &p->p_flag);
882 get_bsdthread_info(thread)->uu_flag |= UT_LP64;
883 } else {
884 OSBitAndAtomic(~((uint32_t)P_LP64), &p->p_flag);
885 get_bsdthread_info(thread)->uu_flag &= ~UT_LP64;
886 }
887 task_set_mach_header_address(task, result->mach_header);
888
889 ret = thread_state_initialize(thread);
890 if (ret != KERN_SUCCESS) {
891 return ret;
892 }
893
894 if (result->threadstate) {
895 uint32_t *ts = result->threadstate;
896 uint32_t total_size = (uint32_t)result->threadstate_sz;
897
898 while (total_size > 0) {
899 uint32_t flavor = *ts++;
900 uint32_t size = *ts++;
901
902 ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
903 if (ret) {
904 return ret;
905 }
906 ts += size;
907 total_size -= (size + 2) * sizeof(uint32_t);
908 }
909 }
910
911 thread_setentrypoint(thread, result->entry_point);
912
913 return KERN_SUCCESS;
914 }
915
916 #if (DEVELOPMENT || DEBUG)
917 extern char panic_on_proc_crash[];
918 extern int use_panic_on_proc_crash;
919
920 extern char panic_on_proc_exit[];
921 extern int use_panic_on_proc_exit;
922
923 extern char panic_on_proc_spawn_fail[];
924 extern int use_panic_on_proc_spawn_fail;
925
926 static inline void
set_crash_behavior_from_bootarg(proc_t p)927 set_crash_behavior_from_bootarg(proc_t p)
928 {
929 if (use_panic_on_proc_crash && strcmp(p->p_comm, panic_on_proc_crash) == 0) {
930 printf("will panic on proc crash: %s\n", p->p_comm);
931 p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_CRASH;
932 }
933
934 if (use_panic_on_proc_exit && strcmp(p->p_comm, panic_on_proc_exit) == 0) {
935 printf("will panic on proc exit: %s\n", p->p_comm);
936 p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_EXIT;
937 }
938
939 if (use_panic_on_proc_spawn_fail && strcmp(p->p_comm, panic_on_proc_spawn_fail) == 0) {
940 printf("will panic on proc spawn fail: %s\n", p->p_comm);
941 p->p_crash_behavior |= POSIX_SPAWN_PANIC_ON_SPAWN_FAIL;
942 }
943 }
944 #endif
945
946 void
set_proc_name(struct image_params * imgp,proc_t p)947 set_proc_name(struct image_params *imgp, proc_t p)
948 {
949 int p_name_len = sizeof(p->p_name) - 1;
950
951 if (imgp->ip_ndp->ni_cnd.cn_namelen > p_name_len) {
952 imgp->ip_ndp->ni_cnd.cn_namelen = p_name_len;
953 }
954
955 bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_name,
956 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
957 p->p_name[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
958
959 if (imgp->ip_ndp->ni_cnd.cn_namelen > MAXCOMLEN) {
960 imgp->ip_ndp->ni_cnd.cn_namelen = MAXCOMLEN;
961 }
962
963 bcopy((caddr_t)imgp->ip_ndp->ni_cnd.cn_nameptr, (caddr_t)p->p_comm,
964 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen);
965 p->p_comm[imgp->ip_ndp->ni_cnd.cn_namelen] = '\0';
966
967 #if (DEVELOPMENT || DEBUG)
968 /*
969 * This happens during image activation, so the crash behavior flags from
970 * posix_spawn will have already been set. So we don't have to worry about
971 * this being overridden.
972 */
973 set_crash_behavior_from_bootarg(p);
974 #endif
975 }
976
977 #if __has_feature(ptrauth_calls)
978 /**
979 * Returns a team ID string that may be used to assign a shared region.
980 *
981 * Platform binaries do not have team IDs and will return NULL. Non-platform
982 * binaries without a team ID will be assigned an artificial team ID of ""
983 * (empty string) so that they will not be assigned to the default shared
984 * region.
985 *
986 * @param imgp image parameter block
987 * @return NULL if this is a platform binary, or an appropriate team ID string
988 * otherwise
989 */
990 static inline const char *
get_teamid_for_shared_region(struct image_params * imgp)991 get_teamid_for_shared_region(struct image_params *imgp)
992 {
993 assert(imgp->ip_vp != NULL);
994
995 const char *ret = csvnode_get_teamid(imgp->ip_vp, imgp->ip_arch_offset);
996 if (ret) {
997 return ret;
998 }
999
1000 struct cs_blob *blob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
1001 if (csblob_get_platform_binary(blob)) {
1002 return NULL;
1003 } else {
1004 static const char *NO_TEAM_ID = "";
1005 return NO_TEAM_ID;
1006 }
1007 }
1008
1009 /**
1010 * Determines whether ptrauth should be enabled for the provided arm64 CPU subtype.
1011 *
1012 * @param cpusubtype Mach-O style CPU subtype
1013 * @return whether the CPU subtype matches arm64e with the current ptrauth ABI
1014 */
1015 static inline bool
arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)1016 arm64_cpusubtype_uses_ptrauth(cpu_subtype_t cpusubtype)
1017 {
1018 return (cpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1019 CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(cpusubtype) == CPU_SUBTYPE_ARM64_PTR_AUTH_CURRENT_VERSION;
1020 }
1021
1022 #endif /* __has_feature(ptrauth_calls) */
1023
1024 /**
1025 * Returns whether a type/subtype slice matches the requested
1026 * type/subtype.
1027 *
1028 * @param mask Bits to mask from the requested/tested cpu type
1029 * @param req_cpu Requested cpu type
1030 * @param req_subcpu Requested cpu subtype
1031 * @param test_cpu Tested slice cpu type
1032 * @param test_subcpu Tested slice cpu subtype
1033 */
1034 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)1035 binary_match(cpu_type_t mask, cpu_type_t req_cpu,
1036 cpu_subtype_t req_subcpu, cpu_type_t test_cpu,
1037 cpu_subtype_t test_subcpu)
1038 {
1039 if ((test_cpu & ~mask) != (req_cpu & ~mask)) {
1040 return FALSE;
1041 }
1042
1043 test_subcpu &= ~CPU_SUBTYPE_MASK;
1044 req_subcpu &= ~CPU_SUBTYPE_MASK;
1045
1046 if (test_subcpu != req_subcpu && req_subcpu != (CPU_SUBTYPE_ANY & ~CPU_SUBTYPE_MASK)) {
1047 return FALSE;
1048 }
1049
1050 return TRUE;
1051 }
1052
1053
1054 #define MIN_IOS_TPRO_SDK_VERSION 0x00100000
1055 #define MIN_OSX_TPRO_SDK_VERSION 0x000D0000
1056 #define MIN_TVOS_TPRO_SDK_VERSION 0x000D0000
1057 #define MIN_WATCHOS_TPRO_SDK_VERSION 0x00090000
1058 #define MIN_DRIVERKIT_TPRO_SDK_VERSION 0x00600000
1059
1060 static void
exec_setup_tpro(struct image_params * imgp,load_result_t * load_result)1061 exec_setup_tpro(struct image_params *imgp, load_result_t *load_result)
1062 {
1063 extern boolean_t xprr_tpro_enabled;
1064 extern boolean_t enable_user_modifiable_perms;
1065 uint32_t min_sdk_version = 0;
1066
1067 /* x86-64 translated code cannot take advantage of TPRO */
1068 if (imgp->ip_flags & IMGPF_ROSETTA) {
1069 return;
1070 }
1071
1072 /* Do not enable on 32-bit VA targets */
1073 if (!(imgp->ip_flags & IMGPF_IS_64BIT_ADDR)) {
1074 return;
1075 }
1076
1077 switch (load_result->ip_platform) {
1078 case PLATFORM_IOS:
1079 case PLATFORM_IOSSIMULATOR:
1080 case PLATFORM_MACCATALYST:
1081 min_sdk_version = MIN_IOS_TPRO_SDK_VERSION;
1082 break;
1083 case PLATFORM_MACOS:
1084 min_sdk_version = MIN_OSX_TPRO_SDK_VERSION;
1085 break;
1086 case PLATFORM_TVOS:
1087 case PLATFORM_TVOSSIMULATOR:
1088 min_sdk_version = MIN_TVOS_TPRO_SDK_VERSION;
1089 break;
1090 case PLATFORM_WATCHOS:
1091 case PLATFORM_WATCHOSSIMULATOR:
1092 min_sdk_version = MIN_WATCHOS_TPRO_SDK_VERSION;
1093 break;
1094 case PLATFORM_DRIVERKIT:
1095 min_sdk_version = MIN_DRIVERKIT_TPRO_SDK_VERSION;
1096 break;
1097 default:
1098 /* TPRO is on by default for newer platforms */
1099 break;
1100 }
1101
1102 }
1103
1104 /*
1105 * If the passed in executable's vnode should use the RSR
1106 * shared region, then this should return TRUE, otherwise, return FALSE.
1107 */
1108 static uint32_t rsr_current_version = 0;
1109 boolean_t (*rsr_check_vnode)(void *vnode) = NULL;
1110
1111 boolean_t
vnode_is_rsr(vnode_t vp)1112 vnode_is_rsr(vnode_t vp)
1113 {
1114 if (!(vnode_isreg(vp) && vnode_tag(vp) == VT_APFS)) {
1115 return FALSE;
1116 }
1117
1118 if (rsr_check_vnode != NULL && rsr_check_vnode((void *)vp)) {
1119 return TRUE;
1120 }
1121 return FALSE;
1122 }
1123
1124
1125 static inline void
encode_HR_entitlement(const char * entitlement,HR_flags_t mask,const struct image_params * imgp,load_result_t * load_result)1126 encode_HR_entitlement(const char *entitlement, HR_flags_t mask,
1127 const struct image_params *imgp, load_result_t *load_result)
1128 {
1129 if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
1130 load_result->hardened_runtime_binary |= mask;
1131 }
1132 }
1133
1134 uint32_t
rsr_get_version(void)1135 rsr_get_version(void)
1136 {
1137 return os_atomic_load(&rsr_current_version, relaxed);
1138 }
1139
1140 void
rsr_bump_version(void)1141 rsr_bump_version(void)
1142 {
1143 os_atomic_inc(&rsr_current_version, relaxed);
1144 }
1145
1146 #if XNU_TARGET_OS_OSX
1147 static int
1148 rsr_version_sysctl SYSCTL_HANDLER_ARGS
1149 {
1150 #pragma unused(arg1, arg2, oidp)
1151 int value = rsr_get_version();
1152 int error = SYSCTL_OUT(req, &value, sizeof(int));
1153 if (error) {
1154 return error;
1155 }
1156
1157 if (!req->newptr) {
1158 return 0;
1159 }
1160
1161 error = SYSCTL_IN(req, &value, sizeof(int));
1162 if (error) {
1163 return error;
1164 }
1165 if (value != 0) {
1166 rsr_bump_version();
1167 }
1168 return 0;
1169 }
1170
1171
1172 SYSCTL_PROC(_vm, OID_AUTO, shared_region_control,
1173 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED | CTLFLAG_MASKED,
1174 0, 0, rsr_version_sysctl, "I", "");
1175 #endif /* XNU_TARGET_OS_OSX */
1176
1177 /*
1178 * exec_mach_imgact
1179 *
1180 * Image activator for mach-o 1.0 binaries.
1181 *
1182 * Parameters; struct image_params * image parameter block
1183 *
1184 * Returns: -1 not a fat binary (keep looking)
1185 * -2 Success: encapsulated binary: reread
1186 * >0 Failure: error number
1187 * EBADARCH Mach-o binary, but with an unrecognized
1188 * architecture
1189 * ENOMEM No memory for child process after -
1190 * can only happen after vfork()
1191 *
1192 * Important: This image activator is NOT byte order neutral.
1193 *
1194 * Note: A return value other than -1 indicates subsequent image
1195 * activators should not be given the opportunity to attempt
1196 * to activate the image.
1197 */
1198 static int
exec_mach_imgact(struct image_params * imgp)1199 exec_mach_imgact(struct image_params *imgp)
1200 {
1201 struct mach_header *mach_header = (struct mach_header *)imgp->ip_vdata;
1202 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
1203 int error = 0;
1204 task_t task;
1205 task_t new_task = NULL; /* protected by vfexec */
1206 thread_t thread;
1207 struct uthread *uthread;
1208 vm_map_t old_map = VM_MAP_NULL;
1209 vm_map_t map = VM_MAP_NULL;
1210 load_return_t lret;
1211 load_result_t load_result = {};
1212 struct _posix_spawnattr *psa = NULL;
1213 int spawn = (imgp->ip_flags & IMGPF_SPAWN);
1214 const int vfexec = 0;
1215 int exec = (imgp->ip_flags & IMGPF_EXEC);
1216 os_reason_t exec_failure_reason = OS_REASON_NULL;
1217 boolean_t reslide = FALSE;
1218 char * userspace_coredump_name = NULL;
1219
1220 /*
1221 * make sure it's a Mach-O 1.0 or Mach-O 2.0 binary; the difference
1222 * is a reserved field on the end, so for the most part, we can
1223 * treat them as if they were identical. Reverse-endian Mach-O
1224 * binaries are recognized but not compatible.
1225 */
1226 if ((mach_header->magic == MH_CIGAM) ||
1227 (mach_header->magic == MH_CIGAM_64)) {
1228 error = EBADARCH;
1229 goto bad;
1230 }
1231
1232 if ((mach_header->magic != MH_MAGIC) &&
1233 (mach_header->magic != MH_MAGIC_64)) {
1234 error = -1;
1235 goto bad;
1236 }
1237
1238 if (mach_header->filetype != MH_EXECUTE) {
1239 error = -1;
1240 goto bad;
1241 }
1242
1243 if (imgp->ip_origcputype != 0) {
1244 /* Fat header previously had an idea about this thin file */
1245 if (imgp->ip_origcputype != mach_header->cputype ||
1246 imgp->ip_origcpusubtype != mach_header->cpusubtype) {
1247 error = EBADARCH;
1248 goto bad;
1249 }
1250 } else {
1251 imgp->ip_origcputype = mach_header->cputype;
1252 imgp->ip_origcpusubtype = mach_header->cpusubtype;
1253 }
1254
1255 task = current_task();
1256 thread = current_thread();
1257 uthread = get_bsdthread_info(thread);
1258
1259 if ((mach_header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64) {
1260 imgp->ip_flags |= IMGPF_IS_64BIT_ADDR | IMGPF_IS_64BIT_DATA;
1261 }
1262
1263
1264 /* If posix_spawn binprefs exist, respect those prefs. */
1265 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
1266 if (psa != NULL && psa->psa_binprefs[0] != 0) {
1267 int pr = 0;
1268 for (pr = 0; pr < NBINPREFS; pr++) {
1269 cpu_type_t pref = psa->psa_binprefs[pr];
1270 cpu_subtype_t subpref = psa->psa_subcpuprefs[pr];
1271
1272 if (pref == 0) {
1273 /* No suitable arch in the pref list */
1274 error = EBADARCH;
1275 goto bad;
1276 }
1277
1278 if (pref == CPU_TYPE_ANY) {
1279 /* Jump to regular grading */
1280 goto grade;
1281 }
1282
1283 if (binary_match(CPU_ARCH_MASK, pref, subpref,
1284 imgp->ip_origcputype, imgp->ip_origcpusubtype)) {
1285 goto grade;
1286 }
1287 }
1288 error = EBADARCH;
1289 goto bad;
1290 }
1291 grade:
1292 if (!grade_binary(imgp->ip_origcputype, imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK,
1293 imgp->ip_origcpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
1294 error = EBADARCH;
1295 goto bad;
1296 }
1297
1298 if (validate_potential_simulator_binary(imgp->ip_origcputype, imgp,
1299 imgp->ip_arch_offset, imgp->ip_arch_size) != LOAD_SUCCESS) {
1300 #if __x86_64__
1301 const char *excpath;
1302 error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
1303 os_log_error(OS_LOG_DEFAULT, "Unsupported 32-bit executable: \"%s\"", (error) ? imgp->ip_vp->v_name : excpath);
1304 #endif
1305 error = EBADARCH;
1306 goto bad;
1307 }
1308
1309 #if defined(HAS_APPLE_PAC)
1310 assert(mach_header->cputype == CPU_TYPE_ARM64
1311 );
1312
1313 if ((mach_header->cputype == CPU_TYPE_ARM64 &&
1314 arm64_cpusubtype_uses_ptrauth(mach_header->cpusubtype))
1315 ) {
1316 imgp->ip_flags &= ~IMGPF_NOJOP;
1317 } else {
1318 imgp->ip_flags |= IMGPF_NOJOP;
1319 }
1320 #endif
1321
1322 /* Copy in arguments/environment from the old process */
1323 error = exec_extract_strings(imgp);
1324 if (error) {
1325 goto bad;
1326 }
1327
1328 AUDIT_ARG(argv, imgp->ip_startargv, imgp->ip_argc,
1329 imgp->ip_endargv - imgp->ip_startargv);
1330 AUDIT_ARG(envv, imgp->ip_endargv, imgp->ip_envc,
1331 imgp->ip_endenvv - imgp->ip_endargv);
1332
1333
1334
1335 /* reset local idea of thread, uthread, task */
1336 thread = imgp->ip_new_thread;
1337 uthread = get_bsdthread_info(thread);
1338 task = new_task = get_threadtask(thread);
1339
1340 /*
1341 * Load the Mach-O file.
1342 *
1343 * NOTE: An error after this point indicates we have potentially
1344 * destroyed or overwritten some process state while attempting an
1345 * execve() following a vfork(), which is an unrecoverable condition.
1346 * We send the new process an immediate SIGKILL to avoid it executing
1347 * any instructions in the mutated address space. For true spawns,
1348 * this is not the case, and "too late" is still not too late to
1349 * return an error code to the parent process.
1350 */
1351
1352 /*
1353 * Actually load the image file we previously decided to load.
1354 */
1355 lret = load_machfile(imgp, mach_header, thread, &map, &load_result);
1356 if (lret != LOAD_SUCCESS) {
1357 error = load_return_to_errno(lret);
1358
1359 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1360 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO, 0, 0);
1361 if (lret == LOAD_BADMACHO_UPX) {
1362 set_proc_name(imgp, p);
1363 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_UPX);
1364 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1365 } else {
1366 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1367
1368 if (bootarg_execfailurereports) {
1369 set_proc_name(imgp, p);
1370 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1371 }
1372 }
1373
1374 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1375
1376 goto badtoolate;
1377 }
1378
1379 assert(imgp->ip_free_map == NULL);
1380
1381 /*
1382 * ERROR RECOVERY
1383 *
1384 * load_machfile() returned the new VM map ("map") but we haven't
1385 * committed to it yet.
1386 * Any error path between here and the point where we commit to using
1387 * the new "map" (with swap_task_map()) should deallocate "map".
1388 */
1389
1390 #ifndef KASAN
1391 /*
1392 * Security: zone sanity checks on fresh boot or initproc re-exec.
1393 * launchd by design does not tear down its own service port on USR (rdar://72797967),
1394 * which means here is the earliest point we can assert on empty service port label zone,
1395 * after load_machfile() above terminates old launchd's IPC space.
1396 *
1397 * Disable on KASAN builds since zone_size_allocated() accounts for elements
1398 * under quarantine.
1399 */
1400 if (task_pid(task) == 1) {
1401 zone_userspace_reboot_checks();
1402 }
1403 #endif
1404
1405 proc_lock(p);
1406 p->p_cputype = imgp->ip_origcputype;
1407 p->p_cpusubtype = imgp->ip_origcpusubtype;
1408 proc_setplatformdata(p, load_result.ip_platform, load_result.lr_min_sdk, load_result.lr_sdk);
1409 exec_setup_tpro(imgp, &load_result);
1410
1411 vm_map_set_size_limit(map, proc_limitgetcur(p, RLIMIT_AS));
1412 vm_map_set_data_limit(map, proc_limitgetcur(p, RLIMIT_DATA));
1413 vm_map_set_user_wire_limit(map, (vm_size_t)proc_limitgetcur(p, RLIMIT_MEMLOCK));
1414 #if XNU_TARGET_OS_OSX
1415 if (proc_platform(p) == PLATFORM_IOS) {
1416 assert(vm_map_is_alien(map));
1417 } else {
1418 assert(!vm_map_is_alien(map));
1419 }
1420 #endif /* XNU_TARGET_OS_OSX */
1421 proc_unlock(p);
1422
1423 /*
1424 * Set TPRO flags if enabled
1425 */
1426
1427 /*
1428 * Set code-signing flags if this binary is signed, or if parent has
1429 * requested them on exec.
1430 */
1431 if (load_result.csflags & CS_VALID) {
1432 imgp->ip_csflags |= load_result.csflags &
1433 (CS_VALID | CS_SIGNED | CS_DEV_CODE | CS_LINKER_SIGNED |
1434 CS_HARD | CS_KILL | CS_RESTRICT | CS_ENFORCEMENT | CS_REQUIRE_LV |
1435 CS_FORCED_LV | CS_ENTITLEMENTS_VALIDATED | CS_NO_UNTRUSTED_HELPERS | CS_RUNTIME |
1436 CS_ENTITLEMENT_FLAGS |
1437 CS_EXEC_SET_HARD | CS_EXEC_SET_KILL | CS_EXEC_SET_ENFORCEMENT);
1438 } else {
1439 imgp->ip_csflags &= ~CS_VALID;
1440 }
1441
1442 if (proc_getcsflags(p) & CS_EXEC_SET_HARD) {
1443 imgp->ip_csflags |= CS_HARD;
1444 }
1445 if (proc_getcsflags(p) & CS_EXEC_SET_KILL) {
1446 imgp->ip_csflags |= CS_KILL;
1447 }
1448 if (proc_getcsflags(p) & CS_EXEC_SET_ENFORCEMENT) {
1449 imgp->ip_csflags |= CS_ENFORCEMENT;
1450 }
1451 if (proc_getcsflags(p) & CS_EXEC_INHERIT_SIP) {
1452 if (proc_getcsflags(p) & CS_INSTALLER) {
1453 imgp->ip_csflags |= CS_INSTALLER;
1454 }
1455 if (proc_getcsflags(p) & CS_DATAVAULT_CONTROLLER) {
1456 imgp->ip_csflags |= CS_DATAVAULT_CONTROLLER;
1457 }
1458 if (proc_getcsflags(p) & CS_NVRAM_UNRESTRICTED) {
1459 imgp->ip_csflags |= CS_NVRAM_UNRESTRICTED;
1460 }
1461 }
1462
1463 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
1464 /*
1465 * ptrauth version 0 is a preview ABI. Developers can opt into running
1466 * their own arm64e binaries for local testing, with the understanding
1467 * that future OSes may break ABI.
1468 */
1469 if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
1470 CPU_SUBTYPE_ARM64_PTR_AUTH_VERSION(imgp->ip_origcpusubtype) == 0 &&
1471 !load_result.platform_binary &&
1472 !bootarg_arm64e_preview_abi) {
1473 static bool logged_once = false;
1474 set_proc_name(imgp, p);
1475
1476 printf("%s: not running binary \"%s\" built against preview arm64e ABI\n", __func__, p->p_name);
1477 if (!os_atomic_xchg(&logged_once, true, relaxed)) {
1478 printf("%s: (to allow this, add \"-arm64e_preview_abi\" to boot-args)\n", __func__);
1479 }
1480
1481 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1482 if (bootarg_execfailurereports) {
1483 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1484 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1485 }
1486
1487 /* release new address space since we won't use it */
1488 imgp->ip_free_map = map;
1489 map = VM_MAP_NULL;
1490 goto badtoolate;
1491 }
1492
1493 if ((imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E &&
1494 imgp->ip_origcputype == CPU_TYPE_ARM64 &&
1495 load_result.platform_binary &&
1496 (imgp->ip_flags & IMGPF_DRIVER) != 0) {
1497 set_proc_name(imgp, p);
1498 printf("%s: disallowing arm64 platform driverkit binary \"%s\", should be arm64e\n", __func__, p->p_name);
1499 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_MACHO);
1500 if (bootarg_execfailurereports) {
1501 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1502 exec_failure_reason->osr_flags |= OS_REASON_FLAG_CONSISTENT_FAILURE;
1503 }
1504
1505 /* release new address space since we won't use it */
1506 imgp->ip_free_map = map;
1507 map = VM_MAP_NULL;
1508 goto badtoolate;
1509 }
1510 #endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
1511
1512
1513 load_result.hardened_runtime_binary = 0;
1514 // Propogate which hardened runtime entitlements are active to the apple array
1515 encode_HR_entitlement(kCSWebBrowserHostEntitlement, BrowserHostEntitlementMask, imgp, &load_result);
1516 encode_HR_entitlement(kCSWebBrowserGPUEntitlement, BrowserGPUEntitlementMask, imgp, &load_result);
1517 encode_HR_entitlement(kCSWebBrowserNetworkEntitlement, BrowserNetworkEntitlementMask, imgp, &load_result);
1518 encode_HR_entitlement(kCSWebBrowserWebContentEntitlement, BrowserWebContentEntitlementMask, imgp, &load_result);
1519
1520 /*
1521 * Set up the shared cache region in the new process.
1522 *
1523 * Normally there is a single shared region per architecture.
1524 * However on systems with Pointer Authentication, we can create
1525 * multiple shared caches with the amount of sharing determined
1526 * by team-id or entitlement. Inherited shared region IDs are used
1527 * for system processes that need to match and be able to inspect
1528 * a pre-existing task.
1529 */
1530 int cpu_subtype = 0; /* all cpu_subtypes use the same shared region */
1531 #if __has_feature(ptrauth_calls)
1532 char *shared_region_id = NULL;
1533 size_t len;
1534 char *base;
1535 const char *cbase;
1536 #define HARDENED_RUNTIME_CONTENT_ID "C-"
1537 #define TEAM_ID_PREFIX "T-"
1538 #define ENTITLE_PREFIX "E-"
1539 #define SR_PREFIX_LEN 2
1540 #define SR_ENTITLEMENT "com.apple.pac.shared_region_id"
1541
1542 if (cpu_type() == CPU_TYPE_ARM64 &&
1543 arm64_cpusubtype_uses_ptrauth(p->p_cpusubtype) &&
1544 (imgp->ip_flags & IMGPF_NOJOP) == 0) {
1545 assertf(p->p_cputype == CPU_TYPE_ARM64,
1546 "p %p cpu_type() 0x%x p->p_cputype 0x%x p->p_cpusubtype 0x%x",
1547 p, cpu_type(), p->p_cputype, p->p_cpusubtype);
1548
1549 /*
1550 * arm64e uses pointer authentication, so request a separate
1551 * shared region for this CPU subtype.
1552 */
1553 cpu_subtype = p->p_cpusubtype & ~CPU_SUBTYPE_MASK;
1554
1555 /*
1556 * Determine which shared cache to select based on being told,
1557 * matching a team-id or matching an entitlement.
1558 */
1559 if (load_result.hardened_runtime_binary & BrowserWebContentEntitlementMask) {
1560 len = sizeof(HARDENED_RUNTIME_CONTENT_ID);
1561 shared_region_id = kalloc_data(len, Z_WAITOK | Z_NOFAIL);
1562 strlcpy(shared_region_id, HARDENED_RUNTIME_CONTENT_ID, len);
1563 } else if (imgp->ip_inherited_shared_region_id) {
1564 len = strlen(imgp->ip_inherited_shared_region_id);
1565 shared_region_id = kalloc_data(len + 1, Z_WAITOK | Z_NOFAIL);
1566 memcpy(shared_region_id, imgp->ip_inherited_shared_region_id, len + 1);
1567 } else if ((cbase = get_teamid_for_shared_region(imgp)) != NULL) {
1568 len = strlen(cbase);
1569 if (vm_shared_region_per_team_id) {
1570 shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1571 Z_WAITOK | Z_NOFAIL);
1572 memcpy(shared_region_id, TEAM_ID_PREFIX, SR_PREFIX_LEN);
1573 memcpy(shared_region_id + SR_PREFIX_LEN, cbase, len + 1);
1574 }
1575 } else if ((base = IOVnodeGetEntitlement(imgp->ip_vp,
1576 (int64_t)imgp->ip_arch_offset, SR_ENTITLEMENT)) != NULL) {
1577 len = strlen(base);
1578 if (vm_shared_region_by_entitlement) {
1579 shared_region_id = kalloc_data(len + SR_PREFIX_LEN + 1,
1580 Z_WAITOK | Z_NOFAIL);
1581 memcpy(shared_region_id, ENTITLE_PREFIX, SR_PREFIX_LEN);
1582 memcpy(shared_region_id + SR_PREFIX_LEN, base, len + 1);
1583 }
1584 /* Discard the copy of the entitlement */
1585 kfree_data(base, len + 1);
1586 }
1587 }
1588
1589 if (imgp->ip_flags & IMGPF_RESLIDE) {
1590 reslide = TRUE;
1591 }
1592
1593 /* use "" as the default shared_region_id */
1594 if (shared_region_id == NULL) {
1595 shared_region_id = kalloc_data(1, Z_WAITOK | Z_ZERO | Z_NOFAIL);
1596 }
1597
1598 /* ensure there's a unique pointer signing key for this shared_region_id */
1599 shared_region_key_alloc(shared_region_id,
1600 imgp->ip_inherited_shared_region_id != NULL, imgp->ip_inherited_jop_pid);
1601 task_set_shared_region_id(task, shared_region_id);
1602 shared_region_id = NULL;
1603 #endif /* __has_feature(ptrauth_calls) */
1604
1605 #if CONFIG_ROSETTA
1606 if (imgp->ip_flags & IMGPF_ROSETTA) {
1607 OSBitOrAtomic(P_TRANSLATED, &p->p_flag);
1608 } else if (p->p_flag & P_TRANSLATED) {
1609 OSBitAndAtomic(~P_TRANSLATED, &p->p_flag);
1610 }
1611 #endif
1612
1613 int cputype = cpu_type();
1614
1615 uint32_t rsr_version = 0;
1616 #if XNU_TARGET_OS_OSX
1617 if (vnode_is_rsr(imgp->ip_vp)) {
1618 rsr_version = rsr_get_version();
1619 os_atomic_or(&p->p_ladvflag, P_RSR, relaxed);
1620 os_atomic_or(&p->p_vfs_iopolicy, P_VFS_IOPOLICY_ALTLINK, relaxed);
1621 }
1622 #endif /* XNU_TARGET_OS_OSX */
1623
1624 vm_map_exec(map, task, load_result.is_64bit_addr,
1625 (void *)p->p_fd.fd_rdir, cputype, cpu_subtype, reslide,
1626 (imgp->ip_flags & IMGPF_DRIVER) != 0,
1627 rsr_version);
1628
1629 /*
1630 * Close file descriptors which specify close-on-exec.
1631 */
1632 fdt_exec(p, vfs_context_ucred(imgp->ip_vfs_context),
1633 psa != NULL ? psa->psa_flags : 0, imgp->ip_new_thread, exec);
1634
1635 /*
1636 * deal with set[ug]id.
1637 */
1638 error = exec_handle_sugid(imgp);
1639 if (error) {
1640 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1641 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE, 0, 0);
1642
1643 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SUGID_FAILURE);
1644 if (bootarg_execfailurereports) {
1645 set_proc_name(imgp, p);
1646 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1647 }
1648
1649 /* release new address space since we won't use it */
1650 imgp->ip_free_map = map;
1651 map = VM_MAP_NULL;
1652 goto badtoolate;
1653 }
1654
1655 /*
1656 * Commit to new map.
1657 *
1658 * Swap the new map for the old for target task, which consumes
1659 * our new map reference but each leaves us responsible for the
1660 * old_map reference. That lets us get off the pmap associated
1661 * with it, and then we can release it.
1662 *
1663 * The map needs to be set on the target task which is different
1664 * than current task, thus swap_task_map is used instead of
1665 * vm_map_switch.
1666 */
1667 old_map = swap_task_map(task, thread, map);
1668 #if MACH_ASSERT
1669 /*
1670 * Reset the pmap's process info to prevent ledger checks
1671 * which might fail due to the ledgers being shared between
1672 * the old and new pmaps.
1673 */
1674 vm_map_pmap_set_process(old_map, -1, "<old_map>");
1675 #endif /* MACH_ASSERT */
1676 imgp->ip_free_map = old_map;
1677 old_map = NULL;
1678
1679 lret = activate_exec_state(task, p, thread, &load_result);
1680 if (lret != KERN_SUCCESS) {
1681 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1682 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE, 0, 0);
1683
1684 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_ACTV_THREADSTATE);
1685 if (bootarg_execfailurereports) {
1686 set_proc_name(imgp, p);
1687 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1688 }
1689
1690 goto badtoolate;
1691 }
1692
1693 /*
1694 * deal with voucher on exec-calling thread.
1695 */
1696 if (imgp->ip_new_thread == NULL) {
1697 thread_set_mach_voucher(current_thread(), IPC_VOUCHER_NULL);
1698 }
1699
1700 /* Make sure we won't interrupt ourself signalling a partial process */
1701 if (!vfexec && !spawn && (p->p_lflag & P_LTRACED)) {
1702 psignal(p, SIGTRAP);
1703 }
1704
1705 if (load_result.unixproc &&
1706 create_unix_stack(get_task_map(task),
1707 &load_result,
1708 p) != KERN_SUCCESS) {
1709 error = load_return_to_errno(LOAD_NOSPACE);
1710
1711 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1712 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC, 0, 0);
1713
1714 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_STACK_ALLOC);
1715 if (bootarg_execfailurereports) {
1716 set_proc_name(imgp, p);
1717 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1718 }
1719
1720 goto badtoolate;
1721 }
1722
1723 if (load_result.hardened_runtime_binary) {
1724 if (cs_debug) {
1725 printf("setting hardened runtime with entitlement mask= "
1726 "0x%x on task: pid = %d\n",
1727 load_result.hardened_runtime_binary,
1728 proc_getpid(p));
1729 }
1730 task_set_hardened_runtime(task, true);
1731 }
1732
1733 /*
1734 * The load result will have already been munged by AMFI to include the
1735 * platform binary flag if boot-args dictated it (AMFI will mark anything
1736 * that doesn't go through the upcall path as a platform binary if its
1737 * enforcement is disabled).
1738 */
1739 if (load_result.platform_binary) {
1740 if (cs_debug) {
1741 printf("setting platform binary on task: pid = %d\n", proc_getpid(p));
1742 }
1743
1744 /*
1745 * We must use 'task' here because the proc's task has not yet been
1746 * switched to the new one.
1747 */
1748 task_set_platform_binary(task, TRUE);
1749 } else {
1750 if (cs_debug) {
1751 printf("clearing platform binary on task: pid = %d\n", proc_getpid(p));
1752 }
1753
1754 task_set_platform_binary(task, FALSE);
1755 }
1756
1757 #if XNU_TARGET_OS_OSX
1758 /* Disable mach hardening for all 1P tasks which load 3P plugins */
1759 if (imgp->ip_flags & IMGPF_3P_PLUGINS) {
1760 if (cs_debug) {
1761 printf("Disabling some mach hardening on task due to 3P plugins: pid = %d\n", proc_getpid(p));
1762 }
1763 task_disable_mach_hardening(task);
1764 }
1765 #if DEVELOPMENT || DEBUG
1766 /* Disable mach hardening for all tasks if amfi_get_out_of_my_way is set.
1767 * Customers will have to turn SIP off to use this boot-arg, and so this is
1768 * only needed internally since we disable this feature when SIP is off. */
1769 if (AMFI_bootarg_disable_mach_hardening) {
1770 if (cs_debug) {
1771 printf("Disabling some mach hardening on task due to AMFI boot-args: pid = %d\n", proc_getpid(p));
1772 }
1773 task_disable_mach_hardening(task);
1774 }
1775 #endif /* DEVELOPMENT || DEBUG */
1776 #endif /* XNU_TARGET_OS_OSX */
1777
1778 /*
1779 * Set starting EXC_GUARD and control port behavior for task now that
1780 * platform and hardened runtime is set. Use the name directly from imgp since we haven't
1781 * set_proc_name() yet. Also make control port for the task and main thread
1782 * immovable/pinned based on task's option.
1783 *
1784 * Must happen before main thread port copyout in exc_add_apple_strings.
1785 */
1786 task_set_exc_guard_ctrl_port_default(task, thread,
1787 imgp->ip_ndp->ni_cnd.cn_nameptr,
1788 (unsigned)imgp->ip_ndp->ni_cnd.cn_namelen,
1789 proc_is_simulated(p),
1790 load_result.ip_platform,
1791 load_result.lr_sdk);
1792
1793 error = exec_add_apple_strings(imgp, &load_result); /* copies out main thread port */
1794
1795 if (error) {
1796 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1797 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT, 0, 0);
1798
1799 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_APPLE_STRING_INIT);
1800 if (bootarg_execfailurereports) {
1801 set_proc_name(imgp, p);
1802 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1803 }
1804 goto badtoolate;
1805 }
1806
1807 /* Switch to target task's map to copy out strings */
1808 old_map = vm_map_switch(get_task_map(task));
1809
1810 if (load_result.unixproc) {
1811 user_addr_t ap;
1812
1813 /*
1814 * Copy the strings area out into the new process address
1815 * space.
1816 */
1817 ap = p->user_stack;
1818 error = exec_copyout_strings(imgp, &ap);
1819 if (error) {
1820 vm_map_switch(old_map);
1821
1822 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1823 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS, 0, 0);
1824
1825 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_STRINGS);
1826 if (bootarg_execfailurereports) {
1827 set_proc_name(imgp, p);
1828 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1829 }
1830 goto badtoolate;
1831 }
1832 /* Set the stack */
1833 thread_setuserstack(thread, ap);
1834 }
1835
1836 if (load_result.dynlinker || load_result.is_rosetta) {
1837 user_addr_t ap;
1838 int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
1839
1840 /* Adjust the stack */
1841 ap = thread_adjuserstack(thread, -new_ptr_size);
1842 error = copyoutptr(load_result.mach_header, ap, new_ptr_size);
1843
1844 if (error) {
1845 vm_map_switch(old_map);
1846
1847 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1848 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER, 0, 0);
1849
1850 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_DYNLINKER);
1851 if (bootarg_execfailurereports) {
1852 set_proc_name(imgp, p);
1853 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1854 }
1855 goto badtoolate;
1856 }
1857 error = task_set_dyld_info(task, load_result.all_image_info_addr,
1858 load_result.all_image_info_size, false);
1859 if (error) {
1860 vm_map_switch(old_map);
1861
1862 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1863 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
1864
1865 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1866 if (bootarg_execfailurereports) {
1867 set_proc_name(imgp, p);
1868 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1869 }
1870 error = EINVAL;
1871 goto badtoolate;
1872 }
1873 } else {
1874 /*
1875 * No dyld or rosetta loaded, set the TF_DYLD_ALL_IMAGE_FINAL bit on task.
1876 */
1877 error = task_set_dyld_info(task, MACH_VM_MIN_ADDRESS,
1878 0, true);
1879 if (error) {
1880 vm_map_switch(old_map);
1881
1882 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1883 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO, 0, 0);
1884
1885 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SET_DYLD_INFO);
1886 if (bootarg_execfailurereports) {
1887 set_proc_name(imgp, p);
1888 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1889 }
1890 error = EINVAL;
1891 goto badtoolate;
1892 }
1893 }
1894
1895 #if CONFIG_ROSETTA
1896 if (load_result.is_rosetta) {
1897 // Add an fd for the executable file for Rosetta's use
1898 int main_binary_fd;
1899 struct fileproc *fp;
1900
1901 error = falloc_exec(p, imgp->ip_vfs_context, &fp, &main_binary_fd);
1902 if (error) {
1903 vm_map_switch(old_map);
1904
1905 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1906 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1907
1908 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1909 if (bootarg_execfailurereports) {
1910 set_proc_name(imgp, p);
1911 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1912 }
1913 goto badtoolate;
1914 }
1915
1916 error = VNOP_OPEN(imgp->ip_vp, FREAD, imgp->ip_vfs_context);
1917 if (error) {
1918 vm_map_switch(old_map);
1919
1920 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1921 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC, 0, 0);
1922
1923 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MAIN_FD_ALLOC);
1924 if (bootarg_execfailurereports) {
1925 set_proc_name(imgp, p);
1926 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1927 }
1928 goto cleanup_rosetta_fp;
1929 }
1930
1931 fp->fp_glob->fg_flag = FREAD;
1932 fp->fp_glob->fg_ops = &vnops;
1933 fp_set_data(fp, imgp->ip_vp);
1934
1935 proc_fdlock(p);
1936 procfdtbl_releasefd(p, main_binary_fd, NULL);
1937 fp_drop(p, main_binary_fd, fp, 1);
1938 proc_fdunlock(p);
1939
1940 vnode_ref(imgp->ip_vp);
1941
1942 // Pass the dyld load address, main binary fd, and dyld fd on the stack
1943 uint64_t ap = thread_adjuserstack(thread, -24);
1944
1945 error = copyoutptr((user_addr_t)load_result.dynlinker_fd, ap, 8);
1946 if (error) {
1947 vm_map_switch(old_map);
1948
1949 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1950 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1951
1952 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1953 if (bootarg_execfailurereports) {
1954 set_proc_name(imgp, p);
1955 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1956 }
1957 goto cleanup_rosetta_fp;
1958 }
1959
1960 error = copyoutptr(load_result.dynlinker_mach_header, ap + 8, 8);
1961 if (error) {
1962 vm_map_switch(old_map);
1963
1964 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1965 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1966
1967 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1968 if (bootarg_execfailurereports) {
1969 set_proc_name(imgp, p);
1970 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1971 }
1972 goto cleanup_rosetta_fp;
1973 }
1974
1975 error = copyoutptr((user_addr_t)main_binary_fd, ap + 16, 8);
1976 if (error) {
1977 vm_map_switch(old_map);
1978
1979 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1980 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA, 0, 0);
1981
1982 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_COPYOUT_ROSETTA);
1983 if (bootarg_execfailurereports) {
1984 set_proc_name(imgp, p);
1985 exec_failure_reason->osr_flags |= OS_REASON_FLAG_GENERATE_CRASH_REPORT;
1986 }
1987 goto cleanup_rosetta_fp;
1988 }
1989
1990 cleanup_rosetta_fp:
1991 if (error) {
1992 fp_free(p, load_result.dynlinker_fd, load_result.dynlinker_fp);
1993 fp_free(p, main_binary_fd, fp);
1994 goto badtoolate;
1995 }
1996 }
1997
1998 #endif
1999
2000 /* Avoid immediate VM faults back into kernel */
2001 exec_prefault_data(p, imgp, &load_result);
2002
2003 vm_map_switch(old_map);
2004
2005 /*
2006 * Reset signal state.
2007 */
2008 execsigs(p, thread);
2009
2010 /*
2011 * need to cancel async IO requests that can be cancelled and wait for those
2012 * already active. MAY BLOCK!
2013 */
2014 _aio_exec( p );
2015
2016 #if SYSV_SHM
2017 /* FIXME: Till vmspace inherit is fixed: */
2018 if (!vfexec && p->vm_shm) {
2019 shmexec(p);
2020 }
2021 #endif
2022 #if SYSV_SEM
2023 /* Clean up the semaphores */
2024 semexit(p);
2025 #endif
2026
2027 /*
2028 * Remember file name for accounting.
2029 */
2030 p->p_acflag &= ~AFORK;
2031
2032 set_proc_name(imgp, p);
2033
2034 #if CONFIG_SECLUDED_MEMORY
2035 if (secluded_for_apps &&
2036 load_result.platform_binary) {
2037 if (strncmp(p->p_name,
2038 "Camera",
2039 sizeof(p->p_name)) == 0) {
2040 task_set_could_use_secluded_mem(task, TRUE);
2041 } else {
2042 task_set_could_use_secluded_mem(task, FALSE);
2043 }
2044 if (strncmp(p->p_name,
2045 "mediaserverd",
2046 sizeof(p->p_name)) == 0) {
2047 task_set_could_also_use_secluded_mem(task, TRUE);
2048 }
2049 if (strncmp(p->p_name,
2050 "cameracaptured",
2051 sizeof(p->p_name)) == 0) {
2052 task_set_could_also_use_secluded_mem(task, TRUE);
2053 }
2054 }
2055 #endif /* CONFIG_SECLUDED_MEMORY */
2056
2057 #if __arm64__
2058 if (load_result.legacy_footprint) {
2059 task_set_legacy_footprint(task);
2060 }
2061 #endif /* __arm64__ */
2062
2063 pal_dbg_set_task_name(task);
2064
2065 #if DEVELOPMENT || DEBUG
2066 /*
2067 * Update the pid an proc name for importance base if any
2068 */
2069 task_importance_update_owner_info(task);
2070 #endif
2071
2072 proc_setexecutableuuid(p, &load_result.uuid[0]);
2073
2074 #if CONFIG_DTRACE
2075 dtrace_proc_exec(p);
2076 #endif
2077
2078
2079 if (kdebug_enable) {
2080 long args[4] = {};
2081
2082 uintptr_t fsid = 0, fileid = 0;
2083 if (imgp->ip_vattr) {
2084 uint64_t fsid64 = vnode_get_va_fsid(imgp->ip_vattr);
2085 fsid = (uintptr_t)fsid64;
2086 fileid = (uintptr_t)imgp->ip_vattr->va_fileid;
2087 // check for (unexpected) overflow and trace zero in that case
2088 if (fsid != fsid64 || fileid != imgp->ip_vattr->va_fileid) {
2089 fsid = fileid = 0;
2090 }
2091 }
2092 KERNEL_DEBUG_CONSTANT_IST1(TRACE_DATA_EXEC, proc_getpid(p), fsid, fileid, 0,
2093 (uintptr_t)thread_tid(thread));
2094
2095 extern void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
2096 kdebug_proc_name_args(p, args);
2097 KERNEL_DEBUG_CONSTANT_IST1(TRACE_STRING_EXEC, args[0], args[1],
2098 args[2], args[3], (uintptr_t)thread_tid(thread));
2099 }
2100
2101
2102 /*
2103 * If posix_spawned with the START_SUSPENDED flag, stop the
2104 * process before it runs.
2105 */
2106 if (imgp->ip_px_sa != NULL) {
2107 psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
2108 if (psa->psa_flags & POSIX_SPAWN_START_SUSPENDED) {
2109 proc_lock(p);
2110 p->p_stat = SSTOP;
2111 proc_unlock(p);
2112 (void) task_suspend_internal(task);
2113 }
2114 }
2115
2116 /*
2117 * mark as execed
2118 */
2119 OSBitOrAtomic(P_EXEC, &p->p_flag);
2120 proc_resetregister(p);
2121 if (p->p_pptr && (p->p_lflag & P_LPPWAIT)) {
2122 proc_lock(p);
2123 p->p_lflag &= ~P_LPPWAIT;
2124 proc_unlock(p);
2125 wakeup((caddr_t)p->p_pptr);
2126 }
2127
2128 /*
2129 * Set up dext coredumps on kernel panic.
2130 * This requires the following:
2131 * - dext_panic_coredump=1 boot-arg (enabled by default on DEVELOPMENT, DEBUG and certain Seed builds)
2132 * - process must be a driver
2133 * - process must have the com.apple.private.enable-coredump-on-panic entitlement, and the
2134 * entitlement has a string value.
2135 * - process must have the com.apple.private.enable-coredump-on-panic-seed-privacy-approved
2136 * entitlement (Seed builds only).
2137 *
2138 * The core dump file name is formatted with the entitlement string value, followed by a hyphen
2139 * and the process PID.
2140 */
2141 if (enable_dext_coredumps_on_panic &&
2142 (imgp->ip_flags & IMGPF_DRIVER) != 0 &&
2143 (userspace_coredump_name = IOVnodeGetEntitlement(imgp->ip_vp,
2144 (int64_t)imgp->ip_arch_offset, USERSPACE_COREDUMP_PANIC_ENTITLEMENT)) != NULL) {
2145 size_t userspace_coredump_name_len = strlen(userspace_coredump_name);
2146
2147 char core_name[MACH_CORE_FILEHEADER_NAMELEN];
2148 /* 16 - NULL char - strlen("-") - maximum of 5 digits for pid */
2149 snprintf(core_name, MACH_CORE_FILEHEADER_NAMELEN, "%.9s-%d", userspace_coredump_name, proc_getpid(p));
2150
2151 kern_register_userspace_coredump(task, core_name);
2152
2153 /* Discard the copy of the entitlement */
2154 kfree_data(userspace_coredump_name, userspace_coredump_name_len + 1);
2155 userspace_coredump_name = NULL;
2156 }
2157
2158 goto done;
2159
2160 badtoolate:
2161 /* Don't allow child process to execute any instructions */
2162 if (!spawn) {
2163 {
2164 assert(exec_failure_reason != OS_REASON_NULL);
2165 if (bootarg_execfailurereports) {
2166 set_proc_name(imgp, current_proc());
2167 }
2168 psignal_with_reason(current_proc(), SIGKILL, exec_failure_reason);
2169 exec_failure_reason = OS_REASON_NULL;
2170
2171 if (exec) {
2172 /* Terminate the exec copy task */
2173 task_terminate_internal(task);
2174 }
2175 }
2176
2177 /* We can't stop this system call at this point, so just pretend we succeeded */
2178 error = 0;
2179 } else {
2180 os_reason_free(exec_failure_reason);
2181 exec_failure_reason = OS_REASON_NULL;
2182 }
2183
2184 done:
2185 if (load_result.threadstate) {
2186 kfree_data(load_result.threadstate, load_result.threadstate_sz);
2187 load_result.threadstate = NULL;
2188 }
2189
2190 bad:
2191 /* If we hit this, we likely would have leaked an exit reason */
2192 assert(exec_failure_reason == OS_REASON_NULL);
2193 return error;
2194 }
2195
2196
2197
2198
2199 /*
2200 * Our image activator table; this is the table of the image types we are
2201 * capable of loading. We list them in order of preference to ensure the
2202 * fastest image load speed.
2203 *
2204 * XXX hardcoded, for now; should use linker sets
2205 */
2206 struct execsw {
2207 int(*const ex_imgact)(struct image_params *);
2208 const char *ex_name;
2209 }const execsw[] = {
2210 { exec_mach_imgact, "Mach-o Binary" },
2211 { exec_fat_imgact, "Fat Binary" },
2212 { exec_shell_imgact, "Interpreter Script" },
2213 { NULL, NULL}
2214 };
2215
2216
2217 /*
2218 * exec_activate_image
2219 *
2220 * Description: Iterate through the available image activators, and activate
2221 * the image associated with the imgp structure. We start with
2222 * the activator for Mach-o binaries followed by that for Fat binaries
2223 * for Interpreter scripts.
2224 *
2225 * Parameters: struct image_params * Image parameter block
2226 *
2227 * Returns: 0 Success
2228 * ENOEXEC No activator for image.
2229 * EBADEXEC The executable is corrupt/unknown
2230 * execargs_alloc:EINVAL Invalid argument
2231 * execargs_alloc:EACCES Permission denied
2232 * execargs_alloc:EINTR Interrupted function
2233 * execargs_alloc:ENOMEM Not enough space
2234 * exec_save_path:EFAULT Bad address
2235 * exec_save_path:ENAMETOOLONG Filename too long
2236 * exec_check_permissions:EACCES Permission denied
2237 * exec_check_permissions:ENOEXEC Executable file format error
2238 * exec_check_permissions:ETXTBSY Text file busy [misuse of error code]
2239 * exec_check_permissions:???
2240 * namei:???
2241 * vn_rdwr:??? [anything vn_rdwr can return]
2242 * <ex_imgact>:??? [anything an imgact can return]
2243 * EDEADLK Process is being terminated
2244 */
2245 static int
exec_activate_image(struct image_params * imgp)2246 exec_activate_image(struct image_params *imgp)
2247 {
2248 struct nameidata *ndp = NULL;
2249 const char *excpath;
2250 int error;
2251 int resid;
2252 int once = 1; /* save SGUID-ness for interpreted files */
2253 int i;
2254 int itercount = 0;
2255 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2256
2257 /*
2258 * For exec, the translock needs to be taken on old proc and not
2259 * on new shadow proc.
2260 */
2261 if (imgp->ip_flags & IMGPF_EXEC) {
2262 p = current_proc();
2263 }
2264
2265 error = execargs_alloc(imgp);
2266 if (error) {
2267 goto bad_notrans;
2268 }
2269
2270 error = exec_save_path(imgp, imgp->ip_user_fname, imgp->ip_seg, &excpath);
2271 if (error) {
2272 goto bad_notrans;
2273 }
2274
2275 /* Use excpath, which contains the copyin-ed exec path */
2276 DTRACE_PROC1(exec, uintptr_t, excpath);
2277
2278 ndp = kalloc_type(struct nameidata, Z_WAITOK | Z_ZERO | Z_NOFAIL);
2279
2280 NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF | AUDITVNPATH1,
2281 UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2282
2283 again:
2284 error = namei(ndp);
2285 if (error) {
2286 if (error == ERESTART) {
2287 error = EINTR;
2288 }
2289 goto bad_notrans;
2290 }
2291 imgp->ip_ndp = ndp; /* successful namei(); call nameidone() later */
2292 imgp->ip_vp = ndp->ni_vp; /* if set, need to vnode_put() at some point */
2293
2294 /*
2295 * Before we start the transition from binary A to binary B, make
2296 * sure another thread hasn't started exiting the process. We grab
2297 * the proc lock to check p_lflag initially, and the transition
2298 * mechanism ensures that the value doesn't change after we release
2299 * the lock.
2300 */
2301 proc_lock(p);
2302 if (p->p_lflag & P_LEXIT) {
2303 error = EDEADLK;
2304 proc_unlock(p);
2305 goto bad_notrans;
2306 }
2307 error = proc_transstart(p, 1, 0);
2308 proc_unlock(p);
2309 if (error) {
2310 goto bad_notrans;
2311 }
2312
2313 error = exec_check_permissions(imgp);
2314 if (error) {
2315 goto bad;
2316 }
2317
2318 /* Copy; avoid invocation of an interpreter overwriting the original */
2319 if (once) {
2320 once = 0;
2321 *imgp->ip_origvattr = *imgp->ip_vattr;
2322 }
2323
2324 error = vn_rdwr(UIO_READ, imgp->ip_vp, imgp->ip_vdata, PAGE_SIZE, 0,
2325 UIO_SYSSPACE, IO_NODELOCKED,
2326 vfs_context_ucred(imgp->ip_vfs_context),
2327 &resid, vfs_context_proc(imgp->ip_vfs_context));
2328 if (error) {
2329 goto bad;
2330 }
2331
2332 if (resid) {
2333 memset(imgp->ip_vdata + (PAGE_SIZE - resid), 0x0, resid);
2334 }
2335
2336 encapsulated_binary:
2337 /* Limit the number of iterations we will attempt on each binary */
2338 if (++itercount > EAI_ITERLIMIT) {
2339 error = EBADEXEC;
2340 goto bad;
2341 }
2342 error = -1;
2343 for (i = 0; error == -1 && execsw[i].ex_imgact != NULL; i++) {
2344 error = (*execsw[i].ex_imgact)(imgp);
2345
2346 switch (error) {
2347 /* case -1: not claimed: continue */
2348 case -2: /* Encapsulated binary, imgp->ip_XXX set for next iteration */
2349 goto encapsulated_binary;
2350
2351 case -3: /* Interpreter */
2352 #if CONFIG_MACF
2353 /*
2354 * Copy the script label for later use. Note that
2355 * the label can be different when the script is
2356 * actually read by the interpreter.
2357 */
2358 if (imgp->ip_scriptlabelp) {
2359 mac_vnode_label_free(imgp->ip_scriptlabelp);
2360 imgp->ip_scriptlabelp = NULL;
2361 }
2362 imgp->ip_scriptlabelp = mac_vnode_label_alloc(NULL);
2363 if (imgp->ip_scriptlabelp == NULL) {
2364 error = ENOMEM;
2365 break;
2366 }
2367 mac_vnode_label_copy(mac_vnode_label(imgp->ip_vp),
2368 imgp->ip_scriptlabelp);
2369
2370 /*
2371 * Take a ref of the script vnode for later use.
2372 */
2373 if (imgp->ip_scriptvp) {
2374 vnode_put(imgp->ip_scriptvp);
2375 imgp->ip_scriptvp = NULLVP;
2376 }
2377 if (vnode_getwithref(imgp->ip_vp) == 0) {
2378 imgp->ip_scriptvp = imgp->ip_vp;
2379 }
2380 #endif
2381
2382 nameidone(ndp);
2383
2384 vnode_put(imgp->ip_vp);
2385 imgp->ip_vp = NULL; /* already put */
2386 imgp->ip_ndp = NULL; /* already nameidone */
2387
2388 /* Use excpath, which exec_shell_imgact reset to the interpreter */
2389 NDINIT(ndp, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF,
2390 UIO_SYSSPACE, CAST_USER_ADDR_T(excpath), imgp->ip_vfs_context);
2391
2392 proc_transend(p, 0);
2393 goto again;
2394
2395 default:
2396 break;
2397 }
2398 }
2399
2400 if (error == -1) {
2401 error = ENOEXEC;
2402 } else if (error == 0) {
2403 if (imgp->ip_flags & IMGPF_INTERPRET && ndp->ni_vp) {
2404 AUDIT_ARG(vnpath, ndp->ni_vp, ARG_VNODE2);
2405 }
2406
2407 /*
2408 * Call out to allow 3rd party notification of exec.
2409 * Ignore result of kauth_authorize_fileop call.
2410 */
2411 if (kauth_authorize_fileop_has_listeners()) {
2412 kauth_authorize_fileop(vfs_context_ucred(imgp->ip_vfs_context),
2413 KAUTH_FILEOP_EXEC,
2414 (uintptr_t)ndp->ni_vp, 0);
2415 }
2416 }
2417 bad:
2418 proc_transend(p, 0);
2419
2420 bad_notrans:
2421 if (imgp->ip_strings) {
2422 execargs_free(imgp);
2423 }
2424 if (imgp->ip_ndp) {
2425 nameidone(imgp->ip_ndp);
2426 }
2427 kfree_type(struct nameidata, ndp);
2428
2429 return error;
2430 }
2431
2432 /*
2433 * exec_validate_spawnattr_policy
2434 *
2435 * Description: Validates the entitlements required to set the apptype.
2436 *
2437 * Parameters: int psa_apptype posix spawn attribute apptype
2438 *
2439 * Returns: 0 Success
2440 * EPERM Failure
2441 */
2442 static errno_t
exec_validate_spawnattr_policy(int psa_apptype)2443 exec_validate_spawnattr_policy(int psa_apptype)
2444 {
2445 if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2446 int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2447 if (proctype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
2448 if (!IOCurrentTaskHasEntitlement(POSIX_SPAWN_ENTITLEMENT_DRIVER)) {
2449 return EPERM;
2450 }
2451 }
2452 }
2453
2454 return 0;
2455 }
2456
2457 /*
2458 * exec_handle_spawnattr_policy
2459 *
2460 * Description: Decode and apply the posix_spawn apptype, qos clamp, and watchport ports to the task.
2461 *
2462 * Parameters: proc_t p process to apply attributes to
2463 * int psa_apptype posix spawn attribute apptype
2464 *
2465 * Returns: 0 Success
2466 */
2467 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)2468 exec_handle_spawnattr_policy(proc_t p, thread_t thread, int psa_apptype, uint64_t psa_qos_clamp,
2469 task_role_t psa_darwin_role, struct exec_port_actions *port_actions)
2470 {
2471 int apptype = TASK_APPTYPE_NONE;
2472 int qos_clamp = THREAD_QOS_UNSPECIFIED;
2473 task_role_t role = TASK_UNSPECIFIED;
2474
2475 if ((psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) != 0) {
2476 int proctype = psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK;
2477
2478 switch (proctype) {
2479 case POSIX_SPAWN_PROC_TYPE_DAEMON_INTERACTIVE:
2480 apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
2481 break;
2482 case POSIX_SPAWN_PROC_TYPE_DAEMON_STANDARD:
2483 apptype = TASK_APPTYPE_DAEMON_STANDARD;
2484 break;
2485 case POSIX_SPAWN_PROC_TYPE_DAEMON_ADAPTIVE:
2486 apptype = TASK_APPTYPE_DAEMON_ADAPTIVE;
2487 break;
2488 case POSIX_SPAWN_PROC_TYPE_DAEMON_BACKGROUND:
2489 apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
2490 break;
2491 case POSIX_SPAWN_PROC_TYPE_APP_DEFAULT:
2492 apptype = TASK_APPTYPE_APP_DEFAULT;
2493 break;
2494 case POSIX_SPAWN_PROC_TYPE_DRIVER:
2495 apptype = TASK_APPTYPE_DRIVER;
2496 break;
2497 default:
2498 apptype = TASK_APPTYPE_NONE;
2499 /* TODO: Should an invalid value here fail the spawn? */
2500 break;
2501 }
2502 }
2503
2504 if (psa_qos_clamp != POSIX_SPAWN_PROC_CLAMP_NONE) {
2505 switch (psa_qos_clamp) {
2506 case POSIX_SPAWN_PROC_CLAMP_UTILITY:
2507 qos_clamp = THREAD_QOS_UTILITY;
2508 break;
2509 case POSIX_SPAWN_PROC_CLAMP_BACKGROUND:
2510 qos_clamp = THREAD_QOS_BACKGROUND;
2511 break;
2512 case POSIX_SPAWN_PROC_CLAMP_MAINTENANCE:
2513 qos_clamp = THREAD_QOS_MAINTENANCE;
2514 break;
2515 default:
2516 qos_clamp = THREAD_QOS_UNSPECIFIED;
2517 /* TODO: Should an invalid value here fail the spawn? */
2518 break;
2519 }
2520 }
2521
2522 if (psa_darwin_role != PRIO_DARWIN_ROLE_DEFAULT) {
2523 proc_darwin_role_to_task_role(psa_darwin_role, &role);
2524 }
2525
2526 if (apptype != TASK_APPTYPE_NONE ||
2527 qos_clamp != THREAD_QOS_UNSPECIFIED ||
2528 role != TASK_UNSPECIFIED ||
2529 port_actions->portwatch_count) {
2530 proc_set_task_spawnpolicy(proc_task(p), thread, apptype, qos_clamp, role,
2531 port_actions->portwatch_array, port_actions->portwatch_count);
2532 }
2533
2534 if (port_actions->registered_count) {
2535 if (_kernelrpc_mach_ports_register3(proc_task(p),
2536 port_actions->registered_array[0],
2537 port_actions->registered_array[1],
2538 port_actions->registered_array[2])) {
2539 return EINVAL;
2540 }
2541 /* mach_ports_register() consumed the array */
2542 bzero(port_actions->registered_array,
2543 sizeof(port_actions->registered_array));
2544 port_actions->registered_count = 0;
2545 }
2546
2547 return 0;
2548 }
2549
2550 static void
exec_port_actions_destroy(struct exec_port_actions * port_actions)2551 exec_port_actions_destroy(struct exec_port_actions *port_actions)
2552 {
2553 if (port_actions->excport_array) {
2554 for (uint32_t i = 0; i < port_actions->exception_port_count; i++) {
2555 ipc_port_t port = NULL;
2556 if ((port = port_actions->excport_array[i].port) != NULL) {
2557 ipc_port_release_send(port);
2558 }
2559 }
2560 kfree_type(struct exception_port_action_t, port_actions->exception_port_count,
2561 port_actions->excport_array);
2562 }
2563
2564 if (port_actions->portwatch_array) {
2565 for (uint32_t i = 0; i < port_actions->portwatch_count; i++) {
2566 ipc_port_t port = NULL;
2567 if ((port = port_actions->portwatch_array[i]) != NULL) {
2568 ipc_port_release_send(port);
2569 }
2570 }
2571 kfree_type(ipc_port_t, port_actions->portwatch_count,
2572 port_actions->portwatch_array);
2573 }
2574
2575 for (uint32_t i = 0; i < port_actions->registered_count; i++) {
2576 ipc_port_t port = NULL;
2577 if ((port = port_actions->registered_array[i]) != NULL) {
2578 ipc_port_release_send(port);
2579 }
2580 }
2581 }
2582
2583 /*
2584 * exec_handle_port_actions
2585 *
2586 * Description: Go through the _posix_port_actions_t contents,
2587 * calling task_set_special_port, task_set_exception_ports
2588 * and/or audit_session_spawnjoin for the current task.
2589 *
2590 * Parameters: struct image_params * Image parameter block
2591 *
2592 * Returns: 0 Success
2593 * EINVAL Failure
2594 * ENOTSUP Illegal posix_spawn attr flag was set
2595 */
2596 static errno_t
exec_handle_port_actions(struct image_params * imgp,struct exec_port_actions * actions)2597 exec_handle_port_actions(struct image_params *imgp,
2598 struct exec_port_actions *actions)
2599 {
2600 _posix_spawn_port_actions_t pacts = imgp->ip_px_spa;
2601 #if CONFIG_AUDIT
2602 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2603 #endif
2604 _ps_port_action_t *act = NULL;
2605 task_t task = get_threadtask(imgp->ip_new_thread);
2606 ipc_port_t port = NULL;
2607 errno_t ret = 0;
2608 int i = 0, portwatch_i = 0, registered_i = 0, excport_i = 0;
2609 kern_return_t kr;
2610 boolean_t task_has_watchport_boost = task_has_watchports(current_task());
2611 boolean_t in_exec = (imgp->ip_flags & IMGPF_EXEC);
2612 int ptrauth_task_port_count = 0;
2613
2614 for (i = 0; i < pacts->pspa_count; i++) {
2615 act = &pacts->pspa_actions[i];
2616
2617 switch (act->port_type) {
2618 case PSPA_SPECIAL:
2619 #if CONFIG_AUDIT
2620 case PSPA_AU_SESSION:
2621 #endif
2622 break;
2623 case PSPA_EXCEPTION:
2624 if (++actions->exception_port_count > TASK_MAX_EXCEPTION_PORT_COUNT) {
2625 ret = EINVAL;
2626 goto done;
2627 }
2628 break;
2629 case PSPA_IMP_WATCHPORTS:
2630 if (++actions->portwatch_count > TASK_MAX_WATCHPORT_COUNT) {
2631 ret = EINVAL;
2632 goto done;
2633 }
2634 break;
2635 case PSPA_REGISTERED_PORTS:
2636 if (++actions->registered_count > TASK_PORT_REGISTER_MAX) {
2637 ret = EINVAL;
2638 goto done;
2639 }
2640 break;
2641 case PSPA_PTRAUTH_TASK_PORT:
2642 if (++ptrauth_task_port_count > 1) {
2643 ret = EINVAL;
2644 goto done;
2645 }
2646 break;
2647 default:
2648 ret = EINVAL;
2649 goto done;
2650 }
2651 }
2652
2653 if (actions->exception_port_count) {
2654 actions->excport_array = kalloc_type(struct exception_port_action_t,
2655 actions->exception_port_count, Z_WAITOK | Z_ZERO);
2656
2657 if (actions->excport_array == NULL) {
2658 ret = ENOMEM;
2659 goto done;
2660 }
2661 }
2662 if (actions->portwatch_count) {
2663 if (in_exec && task_has_watchport_boost) {
2664 ret = EINVAL;
2665 goto done;
2666 }
2667 actions->portwatch_array = kalloc_type(ipc_port_t,
2668 actions->portwatch_count, Z_WAITOK | Z_ZERO);
2669 if (actions->portwatch_array == NULL) {
2670 ret = ENOMEM;
2671 goto done;
2672 }
2673 }
2674
2675 for (i = 0; i < pacts->pspa_count; i++) {
2676 act = &pacts->pspa_actions[i];
2677
2678 if (MACH_PORT_VALID(act->new_port)) {
2679 kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2680 act->new_port, MACH_MSG_TYPE_COPY_SEND,
2681 (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2682
2683 if (kr != KERN_SUCCESS) {
2684 ret = EINVAL;
2685 goto done;
2686 }
2687 } else {
2688 /* it's NULL or DEAD */
2689 port = CAST_MACH_NAME_TO_PORT(act->new_port);
2690 }
2691
2692 switch (act->port_type) {
2693 case PSPA_SPECIAL:
2694 kr = task_set_special_port(task, act->which, port);
2695
2696 if (kr != KERN_SUCCESS) {
2697 ret = EINVAL;
2698 }
2699 break;
2700
2701 #if CONFIG_AUDIT
2702 case PSPA_AU_SESSION:
2703 ret = audit_session_spawnjoin(p, port);
2704 if (ret) {
2705 /* audit_session_spawnjoin() has already dropped the reference in case of error. */
2706 goto done;
2707 }
2708
2709 break;
2710 #endif
2711 case PSPA_EXCEPTION:
2712 assert(excport_i < actions->exception_port_count);
2713 /* hold on to this till end of spawn */
2714 actions->excport_array[excport_i].port_action = act;
2715 actions->excport_array[excport_i].port = port;
2716 excport_i++;
2717 break;
2718 case PSPA_IMP_WATCHPORTS:
2719 assert(portwatch_i < actions->portwatch_count);
2720 /* hold on to this till end of spawn */
2721 actions->portwatch_array[portwatch_i++] = port;
2722 break;
2723 case PSPA_REGISTERED_PORTS:
2724 assert(registered_i < actions->registered_count);
2725 /* hold on to this till end of spawn */
2726 actions->registered_array[registered_i++] = port;
2727 break;
2728
2729 case PSPA_PTRAUTH_TASK_PORT:
2730 #if (DEVELOPMENT || DEBUG)
2731 #if defined(HAS_APPLE_PAC)
2732 {
2733 task_t ptr_auth_task = convert_port_to_task(port);
2734
2735 if (ptr_auth_task == TASK_NULL) {
2736 ret = EINVAL;
2737 break;
2738 }
2739
2740 imgp->ip_inherited_shared_region_id =
2741 task_get_vm_shared_region_id_and_jop_pid(ptr_auth_task,
2742 &imgp->ip_inherited_jop_pid);
2743
2744 /* Deallocate task ref returned by convert_port_to_task */
2745 task_deallocate(ptr_auth_task);
2746 }
2747 #endif /* HAS_APPLE_PAC */
2748 #endif /* (DEVELOPMENT || DEBUG) */
2749
2750 /* consume the port right in case of success */
2751 ipc_port_release_send(port);
2752 break;
2753 default:
2754 ret = EINVAL;
2755 break;
2756 }
2757
2758 if (ret) {
2759 /* action failed, so release port resources */
2760 ipc_port_release_send(port);
2761 break;
2762 }
2763 }
2764
2765 done:
2766 if (0 != ret) {
2767 DTRACE_PROC1(spawn__port__failure, mach_port_name_t, act->new_port);
2768 }
2769 return ret;
2770 }
2771
2772
2773 /*
2774 * exec_handle_exception_port_actions
2775 *
2776 * Description: Go through the saved exception ports in exec_port_actions,
2777 * calling task_set_exception_ports for the current Task.
2778 * This must happen after image activation, and after exec_resettextvp()
2779 * because task_set_exception_ports checks the `TF_PLATFORM` bit and entitlements.
2780 *
2781 * Parameters: struct image_params * Image parameter block
2782 * struct exec_port_actions * Saved Port Actions
2783 *
2784 * Returns: 0 Success
2785 * EINVAL task_set_exception_ports failed
2786 */
2787 static errno_t
exec_handle_exception_port_actions(const struct image_params * imgp,const struct exec_port_actions * actions)2788 exec_handle_exception_port_actions(const struct image_params *imgp,
2789 const struct exec_port_actions *actions)
2790 {
2791 task_t task = get_threadtask(imgp->ip_new_thread);
2792
2793 for (int i = 0; i < actions->exception_port_count; i++) {
2794 ipc_port_t port = actions->excport_array[i].port;
2795 _ps_port_action_t *act = actions->excport_array[i].port_action;
2796 assert(act != NULL);
2797 kern_return_t kr = task_set_exception_ports(task, act->mask, port,
2798 act->behavior, act->flavor);
2799 if (kr != KERN_SUCCESS) {
2800 DTRACE_PROC1(spawn__exception__port__failure, mach_port_name_t, act->new_port);
2801 return EINVAL;
2802 }
2803 actions->excport_array[i].port = NULL;
2804 }
2805
2806 return 0;
2807 }
2808
2809
2810 /*
2811 * exec_handle_file_actions
2812 *
2813 * Description: Go through the _posix_file_actions_t contents applying the
2814 * open, close, and dup2 operations to the open file table for
2815 * the current process.
2816 *
2817 * Parameters: struct image_params * Image parameter block
2818 *
2819 * Returns: 0 Success
2820 * ???
2821 *
2822 * Note: Actions are applied in the order specified, with the credential
2823 * of the parent process. This is done to permit the parent
2824 * process to utilize POSIX_SPAWN_RESETIDS to drop privilege in
2825 * the child following operations the child may in fact not be
2826 * normally permitted to perform.
2827 */
2828 static int
exec_handle_file_actions(struct image_params * imgp,short psa_flags)2829 exec_handle_file_actions(struct image_params *imgp, short psa_flags)
2830 {
2831 int error = 0;
2832 int action;
2833 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
2834 kauth_cred_t p_cred = vfs_context_ucred(imgp->ip_vfs_context);
2835 _posix_spawn_file_actions_t px_sfap = imgp->ip_px_sfa;
2836 int ival[2]; /* dummy retval for system calls) */
2837 #if CONFIG_AUDIT
2838 struct uthread *uthread = current_uthread();
2839 #endif
2840
2841 for (action = 0; action < px_sfap->psfa_act_count; action++) {
2842 _psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
2843
2844 switch (psfa->psfaa_type) {
2845 case PSFA_OPEN: {
2846 /*
2847 * Open is different, in that it requires the use of
2848 * a path argument, which is normally copied in from
2849 * user space; because of this, we have to support an
2850 * open from kernel space that passes an address space
2851 * context of UIO_SYSSPACE, and casts the address
2852 * argument to a user_addr_t.
2853 */
2854 struct vnode_attr *vap;
2855 struct nameidata *ndp;
2856 int mode = psfa->psfaa_openargs.psfao_mode;
2857 int origfd;
2858 struct {
2859 struct vnode_attr va;
2860 struct nameidata nd;
2861 } *__open_data;
2862
2863 __open_data = kalloc_type(typeof(*__open_data), Z_WAITOK | Z_ZERO);
2864 if (__open_data == NULL) {
2865 error = ENOMEM;
2866 break;
2867 }
2868
2869 vap = &__open_data->va;
2870 ndp = &__open_data->nd;
2871
2872 VATTR_INIT(vap);
2873 /* Mask off all but regular access permissions */
2874 mode = ((mode & ~p->p_fd.fd_cmask) & ALLPERMS) & ~S_ISTXT;
2875 VATTR_SET(vap, va_mode, mode & ACCESSPERMS);
2876
2877 AUDIT_SUBCALL_ENTER(OPEN, p, uthread);
2878
2879 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
2880 CAST_USER_ADDR_T(psfa->psfaa_openargs.psfao_path),
2881 imgp->ip_vfs_context);
2882
2883 error = open1(imgp->ip_vfs_context, ndp,
2884 psfa->psfaa_openargs.psfao_oflag,
2885 vap, NULL, NULL, &origfd, AUTH_OPEN_NOAUTHFD);
2886
2887 kfree_type(typeof(*__open_data), __open_data);
2888
2889 AUDIT_SUBCALL_EXIT(uthread, error);
2890
2891 /*
2892 * If there's an error, or we get the right fd by
2893 * accident, then drop out here. This is easier than
2894 * reworking all the open code to preallocate fd
2895 * slots, and internally taking one as an argument.
2896 */
2897 if (error || origfd == psfa->psfaa_filedes) {
2898 break;
2899 }
2900
2901 /*
2902 * If we didn't fall out from an error, we ended up
2903 * with the wrong fd; so now we've got to try to dup2
2904 * it to the right one.
2905 */
2906 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2907 error = dup2(p, p_cred, origfd, psfa->psfaa_filedes, ival);
2908 AUDIT_SUBCALL_EXIT(uthread, error);
2909 if (error) {
2910 break;
2911 }
2912
2913 /*
2914 * Finally, close the original fd.
2915 */
2916 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2917 error = close_nocancel(p, p_cred, origfd);
2918 AUDIT_SUBCALL_EXIT(uthread, error);
2919 }
2920 break;
2921
2922 case PSFA_DUP2: {
2923 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2924 error = dup2(p, p_cred, psfa->psfaa_filedes,
2925 psfa->psfaa_dup2args.psfad_newfiledes, ival);
2926 AUDIT_SUBCALL_EXIT(uthread, error);
2927 }
2928 break;
2929
2930 case PSFA_FILEPORT_DUP2: {
2931 ipc_port_t port;
2932 kern_return_t kr;
2933 int origfd;
2934
2935 if (!MACH_PORT_VALID(psfa->psfaa_fileport)) {
2936 error = EINVAL;
2937 break;
2938 }
2939
2940 kr = ipc_object_copyin(get_task_ipcspace(current_task()),
2941 psfa->psfaa_fileport, MACH_MSG_TYPE_COPY_SEND,
2942 (ipc_object_t *) &port, 0, NULL, IPC_OBJECT_COPYIN_FLAGS_ALLOW_IMMOVABLE_SEND);
2943
2944 if (kr != KERN_SUCCESS) {
2945 error = EINVAL;
2946 break;
2947 }
2948
2949 error = fileport_makefd(p, port, 0, &origfd);
2950
2951 if (IPC_PORT_NULL != port) {
2952 ipc_port_release_send(port);
2953 }
2954
2955 if (error || origfd == psfa->psfaa_dup2args.psfad_newfiledes) {
2956 break;
2957 }
2958
2959 AUDIT_SUBCALL_ENTER(DUP2, p, uthread);
2960 error = dup2(p, p_cred, origfd,
2961 psfa->psfaa_dup2args.psfad_newfiledes, ival);
2962 AUDIT_SUBCALL_EXIT(uthread, error);
2963 if (error) {
2964 break;
2965 }
2966
2967 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2968 error = close_nocancel(p, p_cred, origfd);
2969 AUDIT_SUBCALL_EXIT(uthread, error);
2970 }
2971 break;
2972
2973 case PSFA_CLOSE: {
2974 AUDIT_SUBCALL_ENTER(CLOSE, p, uthread);
2975 error = close_nocancel(p, p_cred, psfa->psfaa_filedes);
2976 AUDIT_SUBCALL_EXIT(uthread, error);
2977 }
2978 break;
2979
2980 case PSFA_INHERIT: {
2981 struct fileproc *fp;
2982
2983 /*
2984 * Check to see if the descriptor exists, and
2985 * ensure it's -not- marked as close-on-exec.
2986 *
2987 * Attempting to "inherit" a guarded fd will
2988 * result in a error.
2989 */
2990
2991 proc_fdlock(p);
2992 if ((fp = fp_get_noref_locked(p, psfa->psfaa_filedes)) == NULL) {
2993 error = EBADF;
2994 } else if (fp->fp_guard_attrs) {
2995 error = fp_guard_exception(p, psfa->psfaa_filedes,
2996 fp, kGUARD_EXC_NOCLOEXEC);
2997 } else {
2998 fp->fp_flags &= ~FP_CLOEXEC;
2999 error = 0;
3000 }
3001 proc_fdunlock(p);
3002 }
3003 break;
3004
3005 case PSFA_CHDIR: {
3006 /*
3007 * Chdir is different, in that it requires the use of
3008 * a path argument, which is normally copied in from
3009 * user space; because of this, we have to support a
3010 * chdir from kernel space that passes an address space
3011 * context of UIO_SYSSPACE, and casts the address
3012 * argument to a user_addr_t.
3013 */
3014 struct nameidata *nd;
3015 nd = kalloc_type(struct nameidata,
3016 Z_WAITOK | Z_ZERO | Z_NOFAIL);
3017
3018 AUDIT_SUBCALL_ENTER(CHDIR, p, uthread);
3019 NDINIT(nd, LOOKUP, OP_CHDIR, FOLLOW | AUDITVNPATH1, UIO_SYSSPACE,
3020 CAST_USER_ADDR_T(psfa->psfaa_chdirargs.psfac_path),
3021 imgp->ip_vfs_context);
3022
3023 error = chdir_internal(p, imgp->ip_vfs_context, nd, 0);
3024 kfree_type(struct nameidata, nd);
3025 AUDIT_SUBCALL_EXIT(uthread, error);
3026 }
3027 break;
3028
3029 case PSFA_FCHDIR: {
3030 AUDIT_SUBCALL_ENTER(FCHDIR, p, uthread);
3031 error = fchdir(p, imgp->ip_vfs_context,
3032 psfa->psfaa_filedes, false);
3033 AUDIT_SUBCALL_EXIT(uthread, error);
3034 }
3035 break;
3036
3037 default:
3038 error = EINVAL;
3039 break;
3040 }
3041
3042 /* All file actions failures are considered fatal, per POSIX */
3043
3044 if (error) {
3045 if (PSFA_OPEN == psfa->psfaa_type) {
3046 DTRACE_PROC1(spawn__open__failure, uintptr_t,
3047 psfa->psfaa_openargs.psfao_path);
3048 } else {
3049 DTRACE_PROC1(spawn__fd__failure, int, psfa->psfaa_filedes);
3050 }
3051 break;
3052 }
3053 }
3054
3055 if (error != 0 || (psa_flags & POSIX_SPAWN_CLOEXEC_DEFAULT) == 0) {
3056 return error;
3057 }
3058
3059 /*
3060 * If POSIX_SPAWN_CLOEXEC_DEFAULT is set, behave (during
3061 * this spawn only) as if "close on exec" is the default
3062 * disposition of all pre-existing file descriptors. In this case,
3063 * the list of file descriptors mentioned in the file actions
3064 * are the only ones that can be inherited, so mark them now.
3065 *
3066 * The actual closing part comes later, in fdt_exec().
3067 */
3068 proc_fdlock(p);
3069 for (action = 0; action < px_sfap->psfa_act_count; action++) {
3070 _psfa_action_t *psfa = &px_sfap->psfa_act_acts[action];
3071 int fd = psfa->psfaa_filedes;
3072
3073 switch (psfa->psfaa_type) {
3074 case PSFA_DUP2:
3075 case PSFA_FILEPORT_DUP2:
3076 fd = psfa->psfaa_dup2args.psfad_newfiledes;
3077 OS_FALLTHROUGH;
3078 case PSFA_OPEN:
3079 case PSFA_INHERIT:
3080 *fdflags(p, fd) |= UF_INHERIT;
3081 break;
3082
3083 case PSFA_CLOSE:
3084 case PSFA_CHDIR:
3085 case PSFA_FCHDIR:
3086 /*
3087 * Although PSFA_FCHDIR does have a file descriptor, it is not
3088 * *creating* one, thus we do not automatically mark it for
3089 * inheritance under POSIX_SPAWN_CLOEXEC_DEFAULT. A client that
3090 * wishes it to be inherited should use the PSFA_INHERIT action
3091 * explicitly.
3092 */
3093 break;
3094 }
3095 }
3096 proc_fdunlock(p);
3097
3098 return 0;
3099 }
3100
3101 #if CONFIG_MACF
3102 /*
3103 * Check that the extension's data is within the bounds of the
3104 * allocation storing all extensions' data
3105 */
3106 static inline errno_t
exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s * px_s,const _ps_mac_policy_extension_t * ext)3107 exec_spawnattr_validate_policyext_data(const struct ip_px_smpx_s *px_s,
3108 const _ps_mac_policy_extension_t *ext)
3109 {
3110 uint64_t dataend;
3111
3112 if (__improbable(os_add_overflow(ext->dataoff, ext->datalen, &dataend))) {
3113 return EOVERFLOW;
3114 }
3115 if (__improbable(dataend > px_s->datalen)) {
3116 return EINVAL;
3117 }
3118
3119 return 0;
3120 }
3121
3122 /*
3123 * exec_spawnattr_getmacpolicyinfo
3124 */
3125 void *
exec_spawnattr_getmacpolicyinfo(const void * macextensions,const char * policyname,size_t * lenp)3126 exec_spawnattr_getmacpolicyinfo(const void *macextensions, const char *policyname, size_t *lenp)
3127 {
3128 const struct ip_px_smpx_s *px_s = macextensions;
3129 const struct _posix_spawn_mac_policy_extensions *psmx = NULL;
3130 int i;
3131
3132 if (px_s == NULL) {
3133 return NULL;
3134 }
3135
3136 psmx = px_s->array;
3137 if (psmx == NULL) {
3138 return NULL;
3139 }
3140
3141 for (i = 0; i < psmx->psmx_count; i++) {
3142 const _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3143 if (strncmp(extension->policyname, policyname, sizeof(extension->policyname)) == 0) {
3144 if (__improbable(exec_spawnattr_validate_policyext_data(px_s, extension))) {
3145 panic("invalid mac policy extension data");
3146 }
3147 if (lenp != NULL) {
3148 *lenp = (size_t)extension->datalen;
3149 }
3150 return (void *)((uintptr_t)px_s->data + extension->dataoff);
3151 }
3152 }
3153
3154 if (lenp != NULL) {
3155 *lenp = 0;
3156 }
3157 return NULL;
3158 }
3159
3160 static int
spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc * px_args,struct ip_px_smpx_s * pxsp)3161 spawn_copyin_macpolicyinfo(const struct user__posix_spawn_args_desc *px_args,
3162 struct ip_px_smpx_s *pxsp)
3163 {
3164 _posix_spawn_mac_policy_extensions_t psmx = NULL;
3165 uint8_t *data = NULL;
3166 uint64_t datalen = 0;
3167 uint64_t dataoff = 0;
3168 int error = 0;
3169
3170 bzero(pxsp, sizeof(*pxsp));
3171
3172 if (px_args->mac_extensions_size < PS_MAC_EXTENSIONS_SIZE(1) ||
3173 px_args->mac_extensions_size > PAGE_SIZE) {
3174 error = EINVAL;
3175 goto bad;
3176 }
3177
3178 psmx = kalloc_data(px_args->mac_extensions_size, Z_WAITOK);
3179 if (psmx == NULL) {
3180 error = ENOMEM;
3181 goto bad;
3182 }
3183
3184 error = copyin(px_args->mac_extensions, psmx, px_args->mac_extensions_size);
3185 if (error) {
3186 goto bad;
3187 }
3188
3189 size_t extsize = PS_MAC_EXTENSIONS_SIZE(psmx->psmx_count);
3190 if (extsize == 0 || extsize > px_args->mac_extensions_size) {
3191 error = EINVAL;
3192 goto bad;
3193 }
3194
3195 for (int i = 0; i < psmx->psmx_count; i++) {
3196 _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3197 if (extension->datalen == 0 || extension->datalen > PAGE_SIZE) {
3198 error = EINVAL;
3199 goto bad;
3200 }
3201 if (__improbable(os_add_overflow(datalen, extension->datalen, &datalen))) {
3202 error = ENOMEM;
3203 goto bad;
3204 }
3205 }
3206
3207 data = kalloc_data((vm_size_t)datalen, Z_WAITOK);
3208 if (data == NULL) {
3209 error = ENOMEM;
3210 goto bad;
3211 }
3212
3213 for (int i = 0; i < psmx->psmx_count; i++) {
3214 _ps_mac_policy_extension_t *extension = &psmx->psmx_extensions[i];
3215
3216 #if !__LP64__
3217 if (extension->data > UINT32_MAX) {
3218 goto bad;
3219 }
3220 #endif
3221 error = copyin((user_addr_t)extension->data, &data[dataoff], (size_t)extension->datalen);
3222 if (error) {
3223 error = ENOMEM;
3224 goto bad;
3225 }
3226 extension->dataoff = dataoff;
3227 dataoff += extension->datalen;
3228 }
3229
3230 pxsp->array = psmx;
3231 pxsp->data = data;
3232 pxsp->datalen = datalen;
3233 return 0;
3234
3235 bad:
3236 kfree_data(psmx, px_args->mac_extensions_size);
3237 kfree_data(data, (vm_size_t)datalen);
3238 return error;
3239 }
3240 #endif /* CONFIG_MACF */
3241
3242 #if CONFIG_COALITIONS
3243 static inline void
spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])3244 spawn_coalitions_release_all(coalition_t coal[COALITION_NUM_TYPES])
3245 {
3246 for (int c = 0; c < COALITION_NUM_TYPES; c++) {
3247 if (coal[c]) {
3248 coalition_remove_active(coal[c]);
3249 coalition_release(coal[c]);
3250 }
3251 }
3252 }
3253 #endif
3254
3255 #if CONFIG_PERSONAS
3256 static int
spawn_validate_persona(struct _posix_spawn_persona_info * px_persona)3257 spawn_validate_persona(struct _posix_spawn_persona_info *px_persona)
3258 {
3259 int error = 0;
3260 struct persona *persona = NULL;
3261 kauth_cred_t mycred = kauth_cred_get();
3262
3263 if (!IOCurrentTaskHasEntitlement( PERSONA_MGMT_ENTITLEMENT)) {
3264 return EPERM;
3265 }
3266
3267 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3268 if (px_persona->pspi_ngroups > NGROUPS_MAX) {
3269 return EINVAL;
3270 }
3271 }
3272
3273 persona = persona_lookup(px_persona->pspi_id);
3274 if (!persona) {
3275 return ESRCH;
3276 }
3277
3278 // non-root process should not be allowed to set persona with uid/gid 0
3279 if (!kauth_cred_issuser(mycred) &&
3280 (px_persona->pspi_uid == 0 || px_persona->pspi_gid == 0)) {
3281 return EPERM;
3282 }
3283
3284 persona_put(persona);
3285 return error;
3286 }
3287
3288 static bool
kauth_cred_model_setpersona(kauth_cred_t model,struct _posix_spawn_persona_info * px_persona)3289 kauth_cred_model_setpersona(
3290 kauth_cred_t model,
3291 struct _posix_spawn_persona_info *px_persona)
3292 {
3293 bool updated = false;
3294
3295 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_UID) {
3296 updated |= kauth_cred_model_setresuid(model,
3297 px_persona->pspi_uid,
3298 px_persona->pspi_uid,
3299 px_persona->pspi_uid,
3300 KAUTH_UID_NONE);
3301 }
3302
3303 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GID) {
3304 updated |= kauth_cred_model_setresgid(model,
3305 px_persona->pspi_gid,
3306 px_persona->pspi_gid,
3307 px_persona->pspi_gid);
3308 }
3309
3310 if (px_persona->pspi_flags & POSIX_SPAWN_PERSONA_GROUPS) {
3311 updated |= kauth_cred_model_setgroups(model,
3312 px_persona->pspi_groups,
3313 px_persona->pspi_ngroups,
3314 px_persona->pspi_gmuid);
3315 }
3316
3317 return updated;
3318 }
3319
3320 static int
spawn_persona_adopt(proc_t p,struct _posix_spawn_persona_info * px_persona)3321 spawn_persona_adopt(proc_t p, struct _posix_spawn_persona_info *px_persona)
3322 {
3323 struct persona *persona = NULL;
3324
3325 /*
3326 * we want to spawn into the given persona, but we want to override
3327 * the kauth with a different UID/GID combo
3328 */
3329 persona = persona_lookup(px_persona->pspi_id);
3330 if (!persona) {
3331 return ESRCH;
3332 }
3333
3334 return persona_proc_adopt(p, persona,
3335 ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
3336 return kauth_cred_model_setpersona(model, px_persona);
3337 });
3338 }
3339 #endif
3340
3341 #if __arm64__
3342 #if DEVELOPMENT || DEBUG
3343 TUNABLE(int, legacy_footprint_entitlement_mode, "legacy_footprint_entitlement_mode",
3344 LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE);
3345
3346 __startup_func
3347 static void
legacy_footprint_entitlement_mode_init(void)3348 legacy_footprint_entitlement_mode_init(void)
3349 {
3350 /*
3351 * legacy_footprint_entitlement_mode specifies the behavior we want associated
3352 * with the entitlement. The supported modes are:
3353 *
3354 * LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3355 * Indicates that we want every process to have the memory accounting
3356 * that is available in iOS 12.0 and beyond.
3357 *
3358 * LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3359 * Indicates that for every process that has the 'legacy footprint entitlement',
3360 * we want to give it the old iOS 11.0 accounting behavior which accounted some
3361 * of the process's memory to the kernel.
3362 *
3363 * LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3364 * Indicates that for every process that has the 'legacy footprint entitlement',
3365 * we want it to have a higher memory limit which will help them acclimate to the
3366 * iOS 12.0 (& beyond) accounting behavior that does the right accounting.
3367 * The bonus added to the system-wide task limit to calculate this higher memory limit
3368 * is available in legacy_footprint_bonus_mb.
3369 */
3370
3371 if (legacy_footprint_entitlement_mode < LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE ||
3372 legacy_footprint_entitlement_mode > LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE) {
3373 legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE;
3374 }
3375 }
3376 STARTUP(TUNABLES, STARTUP_RANK_MIDDLE, legacy_footprint_entitlement_mode_init);
3377 #else
3378 const int legacy_footprint_entitlement_mode = LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE;
3379 #endif
3380
3381 static inline void
proc_legacy_footprint_entitled(proc_t p,task_t task)3382 proc_legacy_footprint_entitled(proc_t p, task_t task)
3383 {
3384 #pragma unused(p)
3385 boolean_t legacy_footprint_entitled;
3386
3387 switch (legacy_footprint_entitlement_mode) {
3388 case LEGACY_FOOTPRINT_ENTITLEMENT_IGNORE:
3389 /* the entitlement is ignored */
3390 break;
3391 case LEGACY_FOOTPRINT_ENTITLEMENT_IOS11_ACCT:
3392 /* the entitlement grants iOS11 legacy accounting */
3393 legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3394 if (legacy_footprint_entitled) {
3395 task_set_legacy_footprint(task);
3396 }
3397 break;
3398 case LEGACY_FOOTPRINT_ENTITLEMENT_LIMIT_INCREASE:
3399 /* the entitlement grants a footprint limit increase */
3400 legacy_footprint_entitled = memorystatus_task_has_legacy_footprint_entitlement(proc_task(p));
3401 if (legacy_footprint_entitled) {
3402 task_set_extra_footprint_limit(task);
3403 }
3404 break;
3405 default:
3406 break;
3407 }
3408 }
3409
3410 static inline void
proc_ios13extended_footprint_entitled(proc_t p,task_t task)3411 proc_ios13extended_footprint_entitled(proc_t p, task_t task)
3412 {
3413 #pragma unused(p)
3414 boolean_t ios13extended_footprint_entitled;
3415
3416 /* the entitlement grants a footprint limit increase */
3417 ios13extended_footprint_entitled = memorystatus_task_has_ios13extended_footprint_limit(proc_task(p));
3418 if (ios13extended_footprint_entitled) {
3419 task_set_ios13extended_footprint_limit(task);
3420 }
3421 }
3422
3423 static inline void
proc_increased_memory_limit_entitled(proc_t p,task_t task)3424 proc_increased_memory_limit_entitled(proc_t p, task_t task)
3425 {
3426 if (memorystatus_task_has_increased_debugging_memory_limit_entitlement(task)) {
3427 memorystatus_act_on_entitled_developer_task_limit(p);
3428 } else if (memorystatus_task_has_increased_memory_limit_entitlement(task)) {
3429 memorystatus_act_on_entitled_task_limit(p);
3430 }
3431 }
3432
3433 /*
3434 * Check for any of the various entitlements that permit a higher
3435 * task footprint limit or alternate accounting and apply them.
3436 */
3437 static inline void
proc_footprint_entitlement_hacks(proc_t p,task_t task)3438 proc_footprint_entitlement_hacks(proc_t p, task_t task)
3439 {
3440 proc_legacy_footprint_entitled(p, task);
3441 proc_ios13extended_footprint_entitled(p, task);
3442 proc_increased_memory_limit_entitled(p, task);
3443 }
3444 #endif /* __arm64__ */
3445
3446 /*
3447 * Processes with certain entitlements are granted a jumbo-size VM map.
3448 */
3449 static inline void
proc_apply_jit_and_vm_policies(struct image_params * imgp,proc_t p,task_t task)3450 proc_apply_jit_and_vm_policies(struct image_params *imgp, proc_t p, task_t task)
3451 {
3452 #if CONFIG_MACF
3453 bool jit_entitled = false;
3454 #endif /* CONFIG_MACF */
3455 bool needs_jumbo_va = false;
3456 bool needs_extra_jumbo_va = false;
3457 struct _posix_spawnattr *psa = imgp->ip_px_sa;
3458
3459 #if CONFIG_MACF
3460 jit_entitled = (mac_proc_check_map_anon(p, proc_ucred_unsafe(p),
3461 0, 0, 0, MAP_JIT, NULL) == 0);
3462 needs_jumbo_va = jit_entitled || IOTaskHasEntitlement(task,
3463 "com.apple.developer.kernel.extended-virtual-addressing") ||
3464 memorystatus_task_has_increased_memory_limit_entitlement(task) ||
3465 memorystatus_task_has_increased_debugging_memory_limit_entitlement(task);
3466 #else
3467 #pragma unused(p)
3468 #endif /* CONFIG_MACF */
3469
3470
3471 if (needs_jumbo_va) {
3472 vm_map_set_jumbo(get_task_map(task));
3473 }
3474
3475 if (psa && psa->psa_max_addr) {
3476 vm_map_set_max_addr(get_task_map(task), psa->psa_max_addr, false);
3477 }
3478
3479 #if CONFIG_MAP_RANGES
3480 if (task_is_hardened_binary(task) && !proc_is_simulated(p)) {
3481 /*
3482 * This must be done last as it needs to observe
3483 * any kind of VA space growth that was requested.
3484 * This is used by the secure allocator, so
3485 * must be applied to all hardened binaries
3486 */
3487 #if XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT
3488 needs_extra_jumbo_va = IOTaskHasEntitlement(task,
3489 "com.apple.kernel.large-file-virtual-addressing");
3490 #endif /* XNU_TARGET_OS_IOS && EXTENDED_USER_VA_SUPPORT */
3491 vm_map_range_configure(get_task_map(task), needs_extra_jumbo_va);
3492 }
3493 #else
3494 #pragma unused(needs_extra_jumbo_va)
3495 #endif /* CONFIG_MAP_RANGES */
3496
3497 #if CONFIG_MACF
3498 if (jit_entitled) {
3499 vm_map_set_jit_entitled(get_task_map(task));
3500
3501 }
3502 #endif /* CONFIG_MACF */
3503
3504 #if XNU_TARGET_OS_OSX
3505 /* TPRO cannot be enforced on binaries that load 3P plugins on macos - rdar://107420220 */
3506 const bool task_loads_3P_plugins = imgp->ip_flags & IMGPF_3P_PLUGINS;
3507 #endif /* XNU_TARGET_OS_OSX */
3508
3509 if (task_is_hardened_binary(task)
3510 #if XNU_TARGET_OS_OSX
3511 && !task_loads_3P_plugins
3512 #endif /* XNU_TARGET_OS_OSX */
3513 ) {
3514 /*
3515 * Pre-emptively disable TPRO remapping for
3516 * hardened binaries (which do not load 3P plugins)
3517 */
3518 vm_map_set_tpro_enforcement(get_task_map(task));
3519 }
3520 }
3521
3522 static int
spawn_posix_cred_adopt(proc_t p,struct _posix_spawn_posix_cred_info * px_pcred_info)3523 spawn_posix_cred_adopt(proc_t p,
3524 struct _posix_spawn_posix_cred_info *px_pcred_info)
3525 {
3526 int error = 0;
3527
3528 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GID) {
3529 struct setgid_args args = {
3530 .gid = px_pcred_info->pspci_gid,
3531 };
3532 error = setgid(p, &args, NULL);
3533 if (error) {
3534 return error;
3535 }
3536 }
3537
3538 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3539 error = setgroups_internal(p,
3540 px_pcred_info->pspci_ngroups,
3541 px_pcred_info->pspci_groups,
3542 px_pcred_info->pspci_gmuid);
3543 if (error) {
3544 return error;
3545 }
3546 }
3547
3548 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_UID) {
3549 struct setuid_args args = {
3550 .uid = px_pcred_info->pspci_uid,
3551 };
3552 error = setuid(p, &args, NULL);
3553 if (error) {
3554 return error;
3555 }
3556 }
3557 return 0;
3558 }
3559
3560 /*
3561 * posix_spawn
3562 *
3563 * Parameters: uap->pid Pointer to pid return area
3564 * uap->fname File name to exec
3565 * uap->argp Argument list
3566 * uap->envp Environment list
3567 *
3568 * Returns: 0 Success
3569 * EINVAL Invalid argument
3570 * ENOTSUP Not supported
3571 * ENOEXEC Executable file format error
3572 * exec_activate_image:EINVAL Invalid argument
3573 * exec_activate_image:EACCES Permission denied
3574 * exec_activate_image:EINTR Interrupted function
3575 * exec_activate_image:ENOMEM Not enough space
3576 * exec_activate_image:EFAULT Bad address
3577 * exec_activate_image:ENAMETOOLONG Filename too long
3578 * exec_activate_image:ENOEXEC Executable file format error
3579 * exec_activate_image:ETXTBSY Text file busy [misuse of error code]
3580 * exec_activate_image:EAUTH Image decryption failed
3581 * exec_activate_image:EBADEXEC The executable is corrupt/unknown
3582 * exec_activate_image:???
3583 * mac_execve_enter:???
3584 *
3585 * TODO: Expect to need __mac_posix_spawn() at some point...
3586 * Handle posix_spawnattr_t
3587 * Handle posix_spawn_file_actions_t
3588 */
3589 int
posix_spawn(proc_t ap,struct posix_spawn_args * uap,int32_t * retval)3590 posix_spawn(proc_t ap, struct posix_spawn_args *uap, int32_t *retval)
3591 {
3592 proc_t p = ap;
3593 user_addr_t pid = uap->pid;
3594 int ival[2]; /* dummy retval for setpgid() */
3595 char *subsystem_root_path = NULL;
3596 struct image_params *imgp = NULL;
3597 struct vnode_attr *vap = NULL;
3598 struct vnode_attr *origvap = NULL;
3599 struct uthread *uthread = 0; /* compiler complains if not set to 0*/
3600 int error, sig;
3601 int is_64 = IS_64BIT_PROCESS(p);
3602 struct vfs_context context;
3603 struct user__posix_spawn_args_desc px_args = {};
3604 struct _posix_spawnattr px_sa = {};
3605 _posix_spawn_file_actions_t px_sfap = NULL;
3606 _posix_spawn_port_actions_t px_spap = NULL;
3607 struct __kern_sigaction vec;
3608 boolean_t spawn_no_exec = FALSE;
3609 boolean_t proc_transit_set = TRUE;
3610 boolean_t proc_signal_set = TRUE;
3611 boolean_t exec_done = FALSE;
3612 os_reason_t exec_failure_reason = NULL;
3613
3614 struct exec_port_actions port_actions = { };
3615 vm_size_t px_sa_offset = offsetof(struct _posix_spawnattr, psa_ports);
3616 task_t old_task = current_task();
3617 task_t new_task = NULL;
3618 boolean_t should_release_proc_ref = FALSE;
3619 void *inherit = NULL;
3620 uint8_t crash_behavior = 0;
3621 uint64_t crash_behavior_deadline = 0;
3622 #if CONFIG_EXCLAVES
3623 char *task_conclave_id = NULL;
3624 #endif
3625 #if CONFIG_PERSONAS
3626 struct _posix_spawn_persona_info *px_persona = NULL;
3627 #endif
3628 struct _posix_spawn_posix_cred_info *px_pcred_info = NULL;
3629 struct {
3630 struct image_params imgp;
3631 struct vnode_attr va;
3632 struct vnode_attr origva;
3633 } *__spawn_data;
3634
3635 /*
3636 * Allocate a big chunk for locals instead of using stack since these
3637 * structures are pretty big.
3638 */
3639 __spawn_data = kalloc_type(typeof(*__spawn_data), Z_WAITOK | Z_ZERO);
3640 if (__spawn_data == NULL) {
3641 error = ENOMEM;
3642 goto bad;
3643 }
3644 imgp = &__spawn_data->imgp;
3645 vap = &__spawn_data->va;
3646 origvap = &__spawn_data->origva;
3647
3648 /* Initialize the common data in the image_params structure */
3649 imgp->ip_user_fname = uap->path;
3650 imgp->ip_user_argv = uap->argv;
3651 imgp->ip_user_envv = uap->envp;
3652 imgp->ip_vattr = vap;
3653 imgp->ip_origvattr = origvap;
3654 imgp->ip_vfs_context = &context;
3655 imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE);
3656 imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
3657 imgp->ip_mac_return = 0;
3658 imgp->ip_px_persona = NULL;
3659 imgp->ip_px_pcred_info = NULL;
3660 imgp->ip_cs_error = OS_REASON_NULL;
3661 imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
3662 imgp->ip_subsystem_root_path = NULL;
3663 imgp->ip_inherited_shared_region_id = NULL;
3664 imgp->ip_inherited_jop_pid = 0;
3665 uthread_set_exec_data(current_uthread(), imgp);
3666
3667 if (uap->adesc != USER_ADDR_NULL) {
3668 if (is_64) {
3669 error = copyin(uap->adesc, &px_args, sizeof(px_args));
3670 } else {
3671 struct user32__posix_spawn_args_desc px_args32;
3672
3673 error = copyin(uap->adesc, &px_args32, sizeof(px_args32));
3674
3675 /*
3676 * Convert arguments descriptor from external 32 bit
3677 * representation to internal 64 bit representation
3678 */
3679 px_args.attr_size = px_args32.attr_size;
3680 px_args.attrp = CAST_USER_ADDR_T(px_args32.attrp);
3681 px_args.file_actions_size = px_args32.file_actions_size;
3682 px_args.file_actions = CAST_USER_ADDR_T(px_args32.file_actions);
3683 px_args.port_actions_size = px_args32.port_actions_size;
3684 px_args.port_actions = CAST_USER_ADDR_T(px_args32.port_actions);
3685 px_args.mac_extensions_size = px_args32.mac_extensions_size;
3686 px_args.mac_extensions = CAST_USER_ADDR_T(px_args32.mac_extensions);
3687 px_args.coal_info_size = px_args32.coal_info_size;
3688 px_args.coal_info = CAST_USER_ADDR_T(px_args32.coal_info);
3689 px_args.persona_info_size = px_args32.persona_info_size;
3690 px_args.persona_info = CAST_USER_ADDR_T(px_args32.persona_info);
3691 px_args.posix_cred_info_size = px_args32.posix_cred_info_size;
3692 px_args.posix_cred_info = CAST_USER_ADDR_T(px_args32.posix_cred_info);
3693 px_args.subsystem_root_path_size = px_args32.subsystem_root_path_size;
3694 px_args.subsystem_root_path = CAST_USER_ADDR_T(px_args32.subsystem_root_path);
3695 px_args.conclave_id_size = px_args32.conclave_id_size;
3696 px_args.conclave_id = CAST_USER_ADDR_T(px_args32.conclave_id);
3697 }
3698 if (error) {
3699 goto bad;
3700 }
3701
3702 if (px_args.attr_size != 0) {
3703 /*
3704 * We are not copying the port_actions pointer,
3705 * because we already have it from px_args.
3706 * This is a bit fragile: <rdar://problem/16427422>
3707 */
3708
3709 if ((error = copyin(px_args.attrp, &px_sa, px_sa_offset)) != 0) {
3710 goto bad;
3711 }
3712
3713 imgp->ip_px_sa = &px_sa;
3714 }
3715 if (px_args.file_actions_size != 0) {
3716 /* Limit file_actions to allowed number of open files */
3717 size_t maxfa_size = PSF_ACTIONS_SIZE(proc_limitgetcur_nofile(p));
3718
3719 if (px_args.file_actions_size < PSF_ACTIONS_SIZE(1) ||
3720 maxfa_size == 0 || px_args.file_actions_size > maxfa_size) {
3721 error = EINVAL;
3722 goto bad;
3723 }
3724
3725 px_sfap = kalloc_data(px_args.file_actions_size, Z_WAITOK);
3726 if (px_sfap == NULL) {
3727 error = ENOMEM;
3728 goto bad;
3729 }
3730 imgp->ip_px_sfa = px_sfap;
3731
3732 if ((error = copyin(px_args.file_actions, px_sfap,
3733 px_args.file_actions_size)) != 0) {
3734 goto bad;
3735 }
3736
3737 /* Verify that the action count matches the struct size */
3738 size_t psfsize = PSF_ACTIONS_SIZE(px_sfap->psfa_act_count);
3739 if (psfsize == 0 || psfsize != px_args.file_actions_size) {
3740 error = EINVAL;
3741 goto bad;
3742 }
3743 }
3744 if (px_args.port_actions_size != 0) {
3745 /* Limit port_actions to one page of data */
3746 if (px_args.port_actions_size < PS_PORT_ACTIONS_SIZE(1) ||
3747 px_args.port_actions_size > PAGE_SIZE) {
3748 error = EINVAL;
3749 goto bad;
3750 }
3751
3752 px_spap = kalloc_data(px_args.port_actions_size, Z_WAITOK);
3753 if (px_spap == NULL) {
3754 error = ENOMEM;
3755 goto bad;
3756 }
3757 imgp->ip_px_spa = px_spap;
3758
3759 if ((error = copyin(px_args.port_actions, px_spap,
3760 px_args.port_actions_size)) != 0) {
3761 goto bad;
3762 }
3763
3764 /* Verify that the action count matches the struct size */
3765 size_t pasize = PS_PORT_ACTIONS_SIZE(px_spap->pspa_count);
3766 if (pasize == 0 || pasize != px_args.port_actions_size) {
3767 error = EINVAL;
3768 goto bad;
3769 }
3770 }
3771 #if CONFIG_PERSONAS
3772 /* copy in the persona info */
3773 if (px_args.persona_info_size != 0 && px_args.persona_info != 0) {
3774 /* for now, we need the exact same struct in user space */
3775 if (px_args.persona_info_size != sizeof(*px_persona)) {
3776 error = ERANGE;
3777 goto bad;
3778 }
3779
3780 px_persona = kalloc_data(px_args.persona_info_size, Z_WAITOK);
3781 if (px_persona == NULL) {
3782 error = ENOMEM;
3783 goto bad;
3784 }
3785 imgp->ip_px_persona = px_persona;
3786
3787 if ((error = copyin(px_args.persona_info, px_persona,
3788 px_args.persona_info_size)) != 0) {
3789 goto bad;
3790 }
3791 if ((error = spawn_validate_persona(px_persona)) != 0) {
3792 goto bad;
3793 }
3794 }
3795 #endif
3796 /* copy in the posix cred info */
3797 if (px_args.posix_cred_info_size != 0 && px_args.posix_cred_info != 0) {
3798 /* for now, we need the exact same struct in user space */
3799 if (px_args.posix_cred_info_size != sizeof(*px_pcred_info)) {
3800 error = ERANGE;
3801 goto bad;
3802 }
3803
3804 if (!kauth_cred_issuser(kauth_cred_get())) {
3805 error = EPERM;
3806 goto bad;
3807 }
3808
3809 px_pcred_info = kalloc_data(px_args.posix_cred_info_size, Z_WAITOK);
3810 if (px_pcred_info == NULL) {
3811 error = ENOMEM;
3812 goto bad;
3813 }
3814 imgp->ip_px_pcred_info = px_pcred_info;
3815
3816 if ((error = copyin(px_args.posix_cred_info, px_pcred_info,
3817 px_args.posix_cred_info_size)) != 0) {
3818 goto bad;
3819 }
3820
3821 if (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_GROUPS) {
3822 if (px_pcred_info->pspci_ngroups > NGROUPS_MAX) {
3823 error = EINVAL;
3824 goto bad;
3825 }
3826 }
3827 }
3828 #if CONFIG_MACF
3829 if (px_args.mac_extensions_size != 0) {
3830 if ((error = spawn_copyin_macpolicyinfo(&px_args, (struct ip_px_smpx_s *)&imgp->ip_px_smpx)) != 0) {
3831 goto bad;
3832 }
3833 }
3834 #endif /* CONFIG_MACF */
3835 if ((px_args.subsystem_root_path_size > 0) && (px_args.subsystem_root_path_size <= MAXPATHLEN)) {
3836 /*
3837 * If a valid-looking subsystem root has been
3838 * specified...
3839 */
3840 if (IOTaskHasEntitlement(old_task, SPAWN_SUBSYSTEM_ROOT_ENTITLEMENT)) {
3841 /*
3842 * ...AND the parent has the entitlement, copy
3843 * the subsystem root path in.
3844 */
3845 subsystem_root_path = zalloc_flags(ZV_NAMEI,
3846 Z_WAITOK | Z_ZERO | Z_NOFAIL);
3847
3848 if ((error = copyin(px_args.subsystem_root_path, subsystem_root_path, px_args.subsystem_root_path_size))) {
3849 goto bad;
3850 }
3851
3852 /* Paranoia */
3853 subsystem_root_path[px_args.subsystem_root_path_size - 1] = 0;
3854 }
3855 }
3856 #if CONFIG_EXCLAVES
3857 if ((px_args.conclave_id_size > 0) && (px_args.conclave_id_size <= MAXCONCLAVENAME) &&
3858 (exclaves_boot_wait(EXCLAVES_BOOT_STAGE_EXCLAVEKIT) == KERN_SUCCESS)) {
3859 if (px_args.conclave_id) {
3860 if (imgp->ip_px_sa != NULL && (px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3861 /* Conclave id could be set only for true spawn */
3862 error = EINVAL;
3863 goto bad;
3864 }
3865 task_conclave_id = kalloc_data(MAXCONCLAVENAME,
3866 Z_WAITOK | Z_ZERO | Z_NOFAIL);
3867 if ((error = copyin(px_args.conclave_id, task_conclave_id, MAXCONCLAVENAME))) {
3868 goto bad;
3869 }
3870 task_conclave_id[MAXCONCLAVENAME - 1] = 0;
3871 }
3872 }
3873 #endif
3874 }
3875
3876 if (IOTaskHasEntitlement(old_task, SPAWN_SET_PANIC_CRASH_BEHAVIOR)) {
3877 /* Truncate to uint8_t since we only support 2 flags for now */
3878 crash_behavior = (uint8_t)px_sa.psa_crash_behavior;
3879 crash_behavior_deadline = px_sa.psa_crash_behavior_deadline;
3880 }
3881
3882 /* set uthread to parent */
3883 uthread = current_uthread();
3884
3885 /*
3886 * <rdar://6640530>; this does not result in a behaviour change
3887 * relative to Leopard, so there should not be any existing code
3888 * which depends on it.
3889 */
3890
3891 if (imgp->ip_px_sa != NULL) {
3892 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
3893 if ((psa->psa_options & PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) == PSA_OPTION_PLUGIN_HOST_DISABLE_A_KEYS) {
3894 imgp->ip_flags |= IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
3895 }
3896 #if (DEVELOPMENT || DEBUG)
3897 if ((psa->psa_options & PSA_OPTION_ALT_ROSETTA) == PSA_OPTION_ALT_ROSETTA) {
3898 imgp->ip_flags |= (IMGPF_ROSETTA | IMGPF_ALT_ROSETTA);
3899 }
3900 #endif
3901
3902 if ((error = exec_validate_spawnattr_policy(psa->psa_apptype)) != 0) {
3903 goto bad;
3904 }
3905 }
3906
3907 /*
3908 * If we don't have the extension flag that turns "posix_spawn()"
3909 * into "execve() with options", then we will be creating a new
3910 * process which does not inherit memory from the parent process,
3911 * which is one of the most expensive things about using fork()
3912 * and execve().
3913 */
3914 if (imgp->ip_px_sa == NULL || !(px_sa.psa_flags & POSIX_SPAWN_SETEXEC)) {
3915 /* Set the new task's coalition, if it is requested. */
3916 coalition_t coal[COALITION_NUM_TYPES] = { COALITION_NULL };
3917 #if CONFIG_COALITIONS
3918 int i, ncoals;
3919 kern_return_t kr = KERN_SUCCESS;
3920 struct _posix_spawn_coalition_info coal_info;
3921 int coal_role[COALITION_NUM_TYPES];
3922
3923 if (imgp->ip_px_sa == NULL || !px_args.coal_info) {
3924 goto do_fork1;
3925 }
3926
3927 memset(&coal_info, 0, sizeof(coal_info));
3928
3929 if (px_args.coal_info_size > sizeof(coal_info)) {
3930 px_args.coal_info_size = sizeof(coal_info);
3931 }
3932 error = copyin(px_args.coal_info,
3933 &coal_info, px_args.coal_info_size);
3934 if (error != 0) {
3935 goto bad;
3936 }
3937
3938 ncoals = 0;
3939 for (i = 0; i < COALITION_NUM_TYPES; i++) {
3940 uint64_t cid = coal_info.psci_info[i].psci_id;
3941 if (cid != 0) {
3942 /*
3943 * don't allow tasks which are not in a
3944 * privileged coalition to spawn processes
3945 * into coalitions other than their own
3946 */
3947 if (!task_is_in_privileged_coalition(proc_task(p), i) &&
3948 !IOTaskHasEntitlement(proc_task(p), COALITION_SPAWN_ENTITLEMENT)) {
3949 coal_dbg("ERROR: %d not in privilegd "
3950 "coalition of type %d",
3951 proc_getpid(p), i);
3952 spawn_coalitions_release_all(coal);
3953 error = EPERM;
3954 goto bad;
3955 }
3956
3957 coal_dbg("searching for coalition id:%llu", cid);
3958 /*
3959 * take a reference and activation on the
3960 * coalition to guard against free-while-spawn
3961 * races
3962 */
3963 coal[i] = coalition_find_and_activate_by_id(cid);
3964 if (coal[i] == COALITION_NULL) {
3965 coal_dbg("could not find coalition id:%llu "
3966 "(perhaps it has been terminated or reaped)", cid);
3967 /*
3968 * release any other coalition's we
3969 * may have a reference to
3970 */
3971 spawn_coalitions_release_all(coal);
3972 error = ESRCH;
3973 goto bad;
3974 }
3975 if (coalition_type(coal[i]) != i) {
3976 coal_dbg("coalition with id:%lld is not of type:%d"
3977 " (it's type:%d)", cid, i, coalition_type(coal[i]));
3978 spawn_coalitions_release_all(coal);
3979 error = ESRCH;
3980 goto bad;
3981 }
3982 coal_role[i] = coal_info.psci_info[i].psci_role;
3983 ncoals++;
3984 }
3985 }
3986 if (ncoals < COALITION_NUM_TYPES) {
3987 /*
3988 * If the user is attempting to spawn into a subset of
3989 * the known coalition types, then make sure they have
3990 * _at_least_ specified a resource coalition. If not,
3991 * the following fork1() call will implicitly force an
3992 * inheritance from 'p' and won't actually spawn the
3993 * new task into the coalitions the user specified.
3994 * (also the call to coalitions_set_roles will panic)
3995 */
3996 if (coal[COALITION_TYPE_RESOURCE] == COALITION_NULL) {
3997 spawn_coalitions_release_all(coal);
3998 error = EINVAL;
3999 goto bad;
4000 }
4001 }
4002 do_fork1:
4003 #endif /* CONFIG_COALITIONS */
4004
4005 /*
4006 * note that this will implicitly inherit the
4007 * caller's persona (if it exists)
4008 */
4009 error = fork1(p, &imgp->ip_new_thread, PROC_CREATE_SPAWN, coal);
4010 /* returns a thread and task reference */
4011
4012 if (error == 0) {
4013 new_task = get_threadtask(imgp->ip_new_thread);
4014 }
4015 #if CONFIG_COALITIONS
4016 /* set the roles of this task within each given coalition */
4017 if (error == 0) {
4018 kr = coalitions_set_roles(coal, new_task, coal_role);
4019 if (kr != KERN_SUCCESS) {
4020 error = EINVAL;
4021 }
4022 if (kdebug_debugid_enabled(MACHDBG_CODE(DBG_MACH_COALITION,
4023 MACH_COALITION_ADOPT))) {
4024 for (i = 0; i < COALITION_NUM_TYPES; i++) {
4025 if (coal[i] != COALITION_NULL) {
4026 /*
4027 * On 32-bit targets, uniqueid
4028 * will get truncated to 32 bits
4029 */
4030 KDBG_RELEASE(MACHDBG_CODE(
4031 DBG_MACH_COALITION,
4032 MACH_COALITION_ADOPT),
4033 coalition_id(coal[i]),
4034 get_task_uniqueid(new_task));
4035 }
4036 }
4037 }
4038 }
4039
4040 /* drop our references and activations - fork1() now holds them */
4041 spawn_coalitions_release_all(coal);
4042 #endif /* CONFIG_COALITIONS */
4043 if (error != 0) {
4044 goto bad;
4045 }
4046 imgp->ip_flags |= IMGPF_SPAWN; /* spawn w/o exec */
4047 spawn_no_exec = TRUE; /* used in later tests */
4048 } else {
4049 /* Adjust the user proc count */
4050 (void)chgproccnt(kauth_getruid(), 1);
4051 /*
4052 * For execve case, create a new proc, task and thread
4053 * but don't make the proc visible to userland. After
4054 * image activation, the new proc would take place of
4055 * the old proc in pid hash and other lists that make
4056 * the proc visible to the system.
4057 */
4058 imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
4059
4060 /* task and thread ref returned by cloneproc */
4061 if (imgp->ip_new_thread == NULL) {
4062 (void)chgproccnt(kauth_getruid(), -1);
4063 error = ENOMEM;
4064 goto bad;
4065 }
4066
4067 new_task = get_threadtask(imgp->ip_new_thread);
4068 imgp->ip_flags |= IMGPF_EXEC;
4069 }
4070
4071 p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
4072
4073 if (spawn_no_exec) {
4074 /*
4075 * We had to wait until this point before firing the
4076 * proc:::create probe, otherwise p would not point to the
4077 * child process.
4078 */
4079 DTRACE_PROC1(create, proc_t, p);
4080 }
4081 assert(p != NULL);
4082
4083 if (subsystem_root_path) {
4084 /* If a subsystem root was specified, swap it in */
4085 char * old_subsystem_root_path = p->p_subsystem_root_path;
4086 p->p_subsystem_root_path = subsystem_root_path;
4087 subsystem_root_path = old_subsystem_root_path;
4088 }
4089
4090 p->p_crash_behavior = crash_behavior;
4091 p->p_crash_behavior_deadline = crash_behavior_deadline;
4092
4093 p->p_crash_count = px_sa.psa_crash_count;
4094 p->p_throttle_timeout = px_sa.psa_throttle_timeout;
4095
4096 /* We'll need the subsystem root for setting up Apple strings */
4097 imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
4098
4099 context.vc_thread = imgp->ip_new_thread;
4100 context.vc_ucred = proc_ucred_unsafe(p); /* in init */
4101
4102 /*
4103 * Post fdt_fork(), pre exec_handle_sugid() - this is where we want
4104 * to handle the file_actions.
4105 */
4106
4107 /* Has spawn file actions? */
4108 if (imgp->ip_px_sfa != NULL) {
4109 /*
4110 * The POSIX_SPAWN_CLOEXEC_DEFAULT flag
4111 * is handled in exec_handle_file_actions().
4112 */
4113 #if CONFIG_AUDIT
4114 /*
4115 * The file actions auditing can overwrite the upath of
4116 * AUE_POSIX_SPAWN audit record. Save the audit record.
4117 */
4118 struct kaudit_record *save_uu_ar = uthread->uu_ar;
4119 uthread->uu_ar = NULL;
4120 #endif
4121 error = exec_handle_file_actions(imgp,
4122 imgp->ip_px_sa != NULL ? px_sa.psa_flags : 0);
4123 #if CONFIG_AUDIT
4124 /* Restore the AUE_POSIX_SPAWN audit record. */
4125 uthread->uu_ar = save_uu_ar;
4126 #endif
4127 if (error != 0) {
4128 goto bad;
4129 }
4130 }
4131
4132 /* Has spawn port actions? */
4133 if (imgp->ip_px_spa != NULL) {
4134 #if CONFIG_AUDIT
4135 /*
4136 * Do the same for the port actions as we did for the file
4137 * actions. Save the AUE_POSIX_SPAWN audit record.
4138 */
4139 struct kaudit_record *save_uu_ar = uthread->uu_ar;
4140 uthread->uu_ar = NULL;
4141 #endif
4142 error = exec_handle_port_actions(imgp, &port_actions);
4143 #if CONFIG_AUDIT
4144 /* Restore the AUE_POSIX_SPAWN audit record. */
4145 uthread->uu_ar = save_uu_ar;
4146 #endif
4147 if (error != 0) {
4148 goto bad;
4149 }
4150 }
4151
4152 /* Has spawn attr? */
4153 if (imgp->ip_px_sa != NULL) {
4154 /*
4155 * Reset UID/GID to parent's RUID/RGID; This works only
4156 * because the operation occurs before the call
4157 * to exec_handle_sugid() by the image activator called
4158 * from exec_activate_image().
4159 *
4160 * POSIX requires that any setuid/setgid bits on the process
4161 * image will take precedence over the spawn attributes
4162 * (re)setting them.
4163 *
4164 * Modifications to p_ucred must be guarded using the
4165 * proc's ucred lock. This prevents others from accessing
4166 * a garbage credential.
4167 */
4168 if (px_sa.psa_flags & POSIX_SPAWN_RESETIDS) {
4169 kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
4170 ^bool (kauth_cred_t parent __unused, kauth_cred_t model){
4171 return kauth_cred_model_setuidgid(model,
4172 kauth_cred_getruid(parent),
4173 kauth_cred_getrgid(parent));
4174 });
4175 }
4176
4177 if (imgp->ip_px_pcred_info) {
4178 if (!spawn_no_exec) {
4179 error = ENOTSUP;
4180 goto bad;
4181 }
4182
4183 error = spawn_posix_cred_adopt(p, imgp->ip_px_pcred_info);
4184 if (error != 0) {
4185 goto bad;
4186 }
4187 }
4188
4189 #if CONFIG_PERSONAS
4190 if (imgp->ip_px_persona != NULL) {
4191 if (!spawn_no_exec) {
4192 error = ENOTSUP;
4193 goto bad;
4194 }
4195
4196 /*
4197 * If we were asked to spawn a process into a new persona,
4198 * do the credential switch now (which may override the UID/GID
4199 * inherit done just above). It's important to do this switch
4200 * before image activation both for reasons stated above, and
4201 * to ensure that the new persona has access to the image/file
4202 * being executed.
4203 */
4204 error = spawn_persona_adopt(p, imgp->ip_px_persona);
4205 if (error != 0) {
4206 goto bad;
4207 }
4208 }
4209 #endif /* CONFIG_PERSONAS */
4210 #if !SECURE_KERNEL
4211 /*
4212 * Disable ASLR for the spawned process.
4213 *
4214 * But only do so if we are not embedded + RELEASE.
4215 * While embedded allows for a boot-arg (-disable_aslr)
4216 * to deal with this (which itself is only honored on
4217 * DEVELOPMENT or DEBUG builds of xnu), it is often
4218 * useful or necessary to disable ASLR on a per-process
4219 * basis for unit testing and debugging.
4220 */
4221 if (px_sa.psa_flags & _POSIX_SPAWN_DISABLE_ASLR) {
4222 OSBitOrAtomic(P_DISABLE_ASLR, &p->p_flag);
4223 }
4224 #endif /* !SECURE_KERNEL */
4225
4226 /* Randomize high bits of ASLR slide */
4227 if (px_sa.psa_flags & _POSIX_SPAWN_HIGH_BITS_ASLR) {
4228 imgp->ip_flags |= IMGPF_HIGH_BITS_ASLR;
4229 }
4230
4231 #if !SECURE_KERNEL
4232 /*
4233 * Forcibly disallow execution from data pages for the spawned process
4234 * even if it would otherwise be permitted by the architecture default.
4235 */
4236 if (px_sa.psa_flags & _POSIX_SPAWN_ALLOW_DATA_EXEC) {
4237 imgp->ip_flags |= IMGPF_ALLOW_DATA_EXEC;
4238 }
4239 #endif /* !SECURE_KERNEL */
4240
4241 #if __has_feature(ptrauth_calls)
4242 if (vm_shared_region_reslide_aslr && is_64 && (px_sa.psa_flags & _POSIX_SPAWN_RESLIDE)) {
4243 imgp->ip_flags |= IMGPF_RESLIDE;
4244 }
4245 #endif /* __has_feature(ptrauth_calls) */
4246
4247 if ((px_sa.psa_apptype & POSIX_SPAWN_PROC_TYPE_MASK) ==
4248 POSIX_SPAWN_PROC_TYPE_DRIVER) {
4249 imgp->ip_flags |= IMGPF_DRIVER;
4250 }
4251 }
4252
4253 /*
4254 * Disable ASLR during image activation. This occurs either if the
4255 * _POSIX_SPAWN_DISABLE_ASLR attribute was found above or if
4256 * P_DISABLE_ASLR was inherited from the parent process.
4257 */
4258 if (p->p_flag & P_DISABLE_ASLR) {
4259 imgp->ip_flags |= IMGPF_DISABLE_ASLR;
4260 }
4261
4262 /*
4263 * Clear transition flag so we won't hang if exec_activate_image() causes
4264 * an automount (and launchd does a proc sysctl to service it).
4265 *
4266 * <rdar://problem/6848672>, <rdar://problem/5959568>.
4267 */
4268 proc_transend(p, 0);
4269 proc_transit_set = 0;
4270
4271 if (!spawn_no_exec) {
4272 /*
4273 * Clear the signal lock in case of exec, since
4274 * image activation uses psignal on child process.
4275 */
4276 proc_signalend(p, 0);
4277 proc_signal_set = 0;
4278 }
4279
4280 #if MAC_SPAWN /* XXX */
4281 if (uap->mac_p != USER_ADDR_NULL) {
4282 error = mac_execve_enter(uap->mac_p, imgp);
4283 if (error) {
4284 goto bad;
4285 }
4286 }
4287 #endif
4288
4289
4290 /*
4291 * Activate the image.
4292 * Warning: If activation failed after point of no return, it returns error
4293 * as 0 and pretends the call succeeded.
4294 */
4295 error = exec_activate_image(imgp);
4296 #if defined(HAS_APPLE_PAC)
4297 const uint8_t disable_user_jop = imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE;
4298 ml_task_set_jop_pid_from_shared_region(new_task, disable_user_jop);
4299 ml_task_set_disable_user_jop(new_task, disable_user_jop);
4300 ml_thread_set_disable_user_jop(imgp->ip_new_thread, disable_user_jop);
4301 ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
4302 #endif
4303
4304
4305 /*
4306 * If you've come here to add support for some new HW feature or some per-process or per-vmmap
4307 * or per-pmap flag that needs to be set before the process runs, or are in general lost, here
4308 * is some help. This summary was accurate as of Jul 2022. Use git log as needed. This comment
4309 * is here to prevent a recurrence of rdar://96307913
4310 *
4311 * In posix_spawn, following is what happens:
4312 * 1. Lots of prep and checking work
4313 * 2. Image activation via exec_activate_image(). The new task will get a new pmap here
4314 * 3. More prep work. (YOU ARE HERE)
4315 * 4. exec_resettextvp() is called
4316 * 5. At this point it is safe to check entitlements and code signatures
4317 * 6. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4318 * The new thread is allowed to run in kernel. It cannot yet get to userland
4319 * 7. More things done here. This is your chance to affect the task before it runs in
4320 * userspace
4321 * 8. task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_FINAL_WAIT);
4322 * The new thread is allowed to run in userland
4323 */
4324
4325 if (error == 0 && !spawn_no_exec) {
4326 p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
4327 /* proc ref returned */
4328 should_release_proc_ref = TRUE;
4329 }
4330
4331 if (error == 0) {
4332 /* process completed the exec, but may have failed after point of no return */
4333 exec_done = TRUE;
4334 }
4335
4336 #if CONFIG_EXCLAVES
4337 if (!error && task_conclave_id != NULL) {
4338 kern_return_t kr;
4339 kr = task_add_conclave(new_task, imgp->ip_vp, (int64_t)imgp->ip_arch_offset,
4340 task_conclave_id);
4341 if (kr != KERN_SUCCESS) {
4342 error = EINVAL;
4343 goto bad;
4344 }
4345 }
4346 #endif
4347
4348 if (!error && imgp->ip_px_sa != NULL) {
4349 thread_t child_thread = imgp->ip_new_thread;
4350 uthread_t child_uthread = get_bsdthread_info(child_thread);
4351
4352 /*
4353 * Because of POSIX_SPAWN_SETEXEC, we need to handle this after image
4354 * activation, else when image activation fails (before the point of no
4355 * return) would leave the parent process in a modified state.
4356 */
4357 if (px_sa.psa_flags & POSIX_SPAWN_SETPGROUP) {
4358 struct setpgid_args spga;
4359 spga.pid = proc_getpid(p);
4360 spga.pgid = px_sa.psa_pgroup;
4361 /*
4362 * Effectively, call setpgid() system call; works
4363 * because there are no pointer arguments.
4364 */
4365 if ((error = setpgid(p, &spga, ival)) != 0) {
4366 goto bad_px_sa;
4367 }
4368 }
4369
4370 if (px_sa.psa_flags & POSIX_SPAWN_SETSID) {
4371 error = setsid_internal(p);
4372 if (error != 0) {
4373 goto bad_px_sa;
4374 }
4375 }
4376
4377 /*
4378 * If we have a spawn attr, and it contains signal related flags,
4379 * the we need to process them in the "context" of the new child
4380 * process, so we have to process it following image activation,
4381 * prior to making the thread runnable in user space. This is
4382 * necessitated by some signal information being per-thread rather
4383 * than per-process, and we don't have the new allocation in hand
4384 * until after the image is activated.
4385 */
4386
4387 /*
4388 * Mask a list of signals, instead of them being unmasked, if
4389 * they were unmasked in the parent; note that some signals
4390 * are not maskable.
4391 */
4392 if (px_sa.psa_flags & POSIX_SPAWN_SETSIGMASK) {
4393 child_uthread->uu_sigmask = (px_sa.psa_sigmask & ~sigcantmask);
4394 }
4395 /*
4396 * Default a list of signals instead of ignoring them, if
4397 * they were ignored in the parent. Note that we pass
4398 * spawn_no_exec to setsigvec() to indicate that we called
4399 * fork1() and therefore do not need to call proc_signalstart()
4400 * internally.
4401 */
4402 if (px_sa.psa_flags & POSIX_SPAWN_SETSIGDEF) {
4403 vec.sa_handler = SIG_DFL;
4404 vec.sa_tramp = 0;
4405 vec.sa_mask = 0;
4406 vec.sa_flags = 0;
4407 for (sig = 1; sig < NSIG; sig++) {
4408 if (px_sa.psa_sigdefault & (1 << (sig - 1))) {
4409 error = setsigvec(p, child_thread, sig, &vec, spawn_no_exec);
4410 }
4411 }
4412 }
4413
4414 /*
4415 * Activate the CPU usage monitor, if requested. This is done via a task-wide, per-thread CPU
4416 * usage limit, which will generate a resource exceeded exception if any one thread exceeds the
4417 * limit.
4418 *
4419 * Userland gives us interval in seconds, and the kernel SPI expects nanoseconds.
4420 */
4421 if ((px_sa.psa_cpumonitor_percent != 0) && (px_sa.psa_cpumonitor_percent < UINT8_MAX)) {
4422 /*
4423 * Always treat a CPU monitor activation coming from spawn as entitled. Requiring
4424 * an entitlement to configure the monitor a certain way seems silly, since
4425 * whomever is turning it on could just as easily choose not to do so.
4426 */
4427 error = proc_set_task_ruse_cpu(proc_task(p),
4428 TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC,
4429 (uint8_t)px_sa.psa_cpumonitor_percent,
4430 px_sa.psa_cpumonitor_interval * NSEC_PER_SEC,
4431 0, TRUE);
4432 }
4433
4434
4435 if (px_pcred_info &&
4436 (px_pcred_info->pspci_flags & POSIX_SPAWN_POSIX_CRED_LOGIN)) {
4437 /*
4438 * setlogin() must happen after setsid()
4439 */
4440 setlogin_internal(p, px_pcred_info->pspci_login);
4441 }
4442
4443 bad_px_sa:
4444 if (error != 0) {
4445 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
4446 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR, 0, 0);
4447 exec_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_BAD_PSATTR);
4448 }
4449 }
4450
4451 bad:
4452
4453 if (error == 0) {
4454 /* reset delay idle sleep status if set */
4455 #if CONFIG_DELAY_IDLE_SLEEP
4456 if ((p->p_flag & P_DELAYIDLESLEEP) == P_DELAYIDLESLEEP) {
4457 OSBitAndAtomic(~((uint32_t)P_DELAYIDLESLEEP), &p->p_flag);
4458 }
4459 #endif /* CONFIG_DELAY_IDLE_SLEEP */
4460 /* upon successful spawn, re/set the proc control state */
4461 if (imgp->ip_px_sa != NULL) {
4462 switch (px_sa.psa_pcontrol) {
4463 case POSIX_SPAWN_PCONTROL_THROTTLE:
4464 p->p_pcaction = P_PCTHROTTLE;
4465 break;
4466 case POSIX_SPAWN_PCONTROL_SUSPEND:
4467 p->p_pcaction = P_PCSUSP;
4468 break;
4469 case POSIX_SPAWN_PCONTROL_KILL:
4470 p->p_pcaction = P_PCKILL;
4471 break;
4472 case POSIX_SPAWN_PCONTROL_NONE:
4473 default:
4474 p->p_pcaction = 0;
4475 break;
4476 }
4477 ;
4478 }
4479 exec_resettextvp(p, imgp);
4480
4481 /*
4482 * Enable new task IPC access if exec_activate_image() returned an
4483 * active task. (Checks active bit in ipc_task_enable() under lock).
4484 * Must enable after resettextvp so that task port policies are not evaluated
4485 * until the csblob in the textvp is accurately reflected.
4486 */
4487 ipc_task_enable(new_task);
4488
4489 /* Set task exception ports now that we can check entitlements */
4490 if (imgp->ip_px_spa != NULL) {
4491 error = exec_handle_exception_port_actions(imgp, &port_actions);
4492 }
4493
4494 #if CONFIG_MEMORYSTATUS
4495 /* Set jetsam priority for DriverKit processes */
4496 if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4497 px_sa.psa_priority = JETSAM_PRIORITY_DRIVER_APPLE;
4498 }
4499
4500 /* Has jetsam attributes? */
4501 if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_SET)) {
4502 int32_t memlimit_active = px_sa.psa_memlimit_active;
4503 int32_t memlimit_inactive = px_sa.psa_memlimit_inactive;
4504
4505 memstat_priority_options_t priority_options = MEMSTAT_PRIORITY_OPTIONS_NONE;
4506 if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_USE_EFFECTIVE_PRIORITY)) {
4507 priority_options |= MEMSTAT_PRIORITY_IS_EFFECTIVE;
4508 }
4509 memorystatus_set_priority(p, px_sa.psa_priority, 0,
4510 priority_options);
4511
4512 memlimit_options_t memlimit_options = MEMLIMIT_OPTIONS_NONE;
4513 if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_ACTIVE_FATAL)) {
4514 memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
4515 }
4516 if ((px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_MEMLIMIT_INACTIVE_FATAL)) {
4517 memlimit_options |= MEMLIMIT_INACTIVE_FATAL;
4518 }
4519 if (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND) {
4520 /*
4521 * With 2-level high-water-mark support,
4522 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is no longer relevant,
4523 * as background limits are described via the inactive limit
4524 * slots. However, if the
4525 * POSIX_SPAWN_JETSAM_HIWATER_BACKGROUND is passed in, we
4526 * attempt to mimic previous behavior by forcing the BG limit
4527 * data into the inactive/non-fatal mode and force the active
4528 * slots to hold system_wide/fatal mode.
4529 */
4530 memlimit_options |= MEMLIMIT_ACTIVE_FATAL;
4531 memlimit_options &= ~MEMLIMIT_INACTIVE_FATAL;
4532 memlimit_active = -1;
4533 }
4534 memorystatus_set_memlimits(p, memlimit_active, memlimit_inactive,
4535 memlimit_options);
4536 }
4537
4538 /* Has jetsam relaunch behavior? */
4539 if (imgp->ip_px_sa != NULL && (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK)) {
4540 /*
4541 * Launchd has passed in data indicating the behavior of this process in response to jetsam.
4542 * This data would be used by the jetsam subsystem to determine the position and protection
4543 * offered to this process on dirty -> clean transitions.
4544 */
4545 int relaunch_flags = P_MEMSTAT_RELAUNCH_UNKNOWN;
4546 switch (px_sa.psa_jetsam_flags & POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MASK) {
4547 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_LOW:
4548 relaunch_flags = P_MEMSTAT_RELAUNCH_LOW;
4549 break;
4550 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_MED:
4551 relaunch_flags = P_MEMSTAT_RELAUNCH_MED;
4552 break;
4553 case POSIX_SPAWN_JETSAM_RELAUNCH_BEHAVIOR_HIGH:
4554 relaunch_flags = P_MEMSTAT_RELAUNCH_HIGH;
4555 break;
4556 default:
4557 break;
4558 }
4559 memorystatus_relaunch_flags_update(p, relaunch_flags);
4560 }
4561
4562 #endif /* CONFIG_MEMORYSTATUS */
4563 if (imgp->ip_px_sa != NULL && px_sa.psa_thread_limit > 0) {
4564 task_set_thread_limit(new_task, (uint16_t)px_sa.psa_thread_limit);
4565 }
4566
4567 #if CONFIG_PROC_RESOURCE_LIMITS
4568 if (imgp->ip_px_sa != NULL && (px_sa.psa_port_soft_limit > 0 || px_sa.psa_port_hard_limit > 0)) {
4569 task_set_port_space_limits(new_task, (uint32_t)px_sa.psa_port_soft_limit,
4570 (uint32_t)px_sa.psa_port_hard_limit);
4571 }
4572
4573 if (imgp->ip_px_sa != NULL && (px_sa.psa_filedesc_soft_limit > 0 || px_sa.psa_filedesc_hard_limit > 0)) {
4574 proc_set_filedesc_limits(p, (int)px_sa.psa_filedesc_soft_limit,
4575 (int)px_sa.psa_filedesc_hard_limit);
4576 }
4577 if (imgp->ip_px_sa != NULL && (px_sa.psa_kqworkloop_soft_limit > 0 || px_sa.psa_kqworkloop_hard_limit > 0)) {
4578 proc_set_kqworkloop_limits(p, (int)px_sa.psa_kqworkloop_soft_limit,
4579 (int)px_sa.psa_kqworkloop_hard_limit);
4580 }
4581 #endif /* CONFIG_PROC_RESOURCE_LIMITS */
4582
4583 /* Disable wakeup monitoring for DriverKit processes */
4584 if (px_sa.psa_apptype == POSIX_SPAWN_PROC_TYPE_DRIVER) {
4585 uint32_t flags = WAKEMON_DISABLE;
4586 task_wakeups_monitor_ctl(new_task, &flags, NULL);
4587 }
4588 }
4589
4590
4591 /*
4592 * If we successfully called fork1() or cloneproc, we always need
4593 * to do this. This is because we come back from that call with
4594 * signals blocked in the child, and we have to unblock them, for exec
4595 * case they are unblocked before activation, but for true spawn case
4596 * we want to wait until after we've performed any spawn actions.
4597 * This has to happen before process_signature(), which uses psignal.
4598 */
4599 if (proc_transit_set) {
4600 proc_transend(p, 0);
4601 }
4602
4603 /*
4604 * Drop the signal lock on the child which was taken on our
4605 * behalf by forkproc()/cloneproc() to prevent signals being
4606 * received by the child in a partially constructed state.
4607 */
4608 if (proc_signal_set) {
4609 proc_signalend(p, 0);
4610 }
4611
4612 if (error == 0) {
4613 /*
4614 * We need to initialize the bank context behind the protection of
4615 * the proc_trans lock to prevent a race with exit. We can't do this during
4616 * exec_activate_image because task_bank_init checks entitlements that
4617 * aren't loaded until subsequent calls (including exec_resettextvp).
4618 */
4619 error = proc_transstart(p, 0, 0);
4620
4621 if (error == 0) {
4622 task_bank_init(new_task);
4623 proc_transend(p, 0);
4624 }
4625
4626 #if __arm64__
4627 proc_footprint_entitlement_hacks(p, new_task);
4628 #endif /* __arm64__ */
4629
4630 #if XNU_TARGET_OS_OSX
4631 #define SINGLE_JIT_ENTITLEMENT "com.apple.security.cs.single-jit"
4632 if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
4633 vm_map_single_jit(get_task_map(new_task));
4634 }
4635 #endif /* XNU_TARGET_OS_OSX */
4636
4637 #if __has_feature(ptrauth_calls)
4638 task_set_pac_exception_fatal_flag(new_task);
4639 #endif /* __has_feature(ptrauth_calls) */
4640 task_set_jit_exception_fatal_flag(new_task);
4641 }
4642
4643 /* Inherit task role from old task to new task for exec */
4644 if (error == 0 && !spawn_no_exec) {
4645 proc_inherit_task_role(new_task, old_task);
4646 }
4647
4648 #if CONFIG_ARCADE
4649 if (error == 0) {
4650 /*
4651 * Check to see if we need to trigger an arcade upcall AST now
4652 * that the vnode has been reset on the task.
4653 */
4654 arcade_prepare(new_task, imgp->ip_new_thread);
4655 }
4656 #endif /* CONFIG_ARCADE */
4657
4658 if (error == 0) {
4659 proc_apply_jit_and_vm_policies(imgp, p, new_task);
4660 }
4661
4662 /* Clear the initial wait on the thread before handling spawn policy */
4663 if (imgp && imgp->ip_new_thread) {
4664 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
4665 }
4666
4667 /*
4668 * Apply the spawnattr policy, apptype (which primes the task for importance donation),
4669 * and bind any portwatch ports to the new task.
4670 * This must be done after the exec so that the child's thread is ready,
4671 * and after the in transit state has been released, because priority is
4672 * dropped here so we need to be prepared for a potentially long preemption interval
4673 *
4674 * TODO: Consider splitting this up into separate phases
4675 */
4676 if (error == 0 && imgp->ip_px_sa != NULL) {
4677 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4678
4679 error = exec_handle_spawnattr_policy(p, imgp->ip_new_thread, psa->psa_apptype, psa->psa_qos_clamp,
4680 psa->psa_darwin_role, &port_actions);
4681 }
4682
4683 /* Transfer the turnstile watchport boost to new task if in exec */
4684 if (error == 0 && !spawn_no_exec) {
4685 task_transfer_turnstile_watchports(old_task, new_task, imgp->ip_new_thread);
4686 }
4687
4688 if (error == 0 && imgp->ip_px_sa != NULL) {
4689 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4690
4691 if (psa->psa_no_smt) {
4692 task_set_no_smt(new_task);
4693 }
4694 if (psa->psa_tecs) {
4695 task_set_tecs(new_task);
4696 }
4697 }
4698
4699 if (error == 0 && imgp->ip_px_sa != NULL) {
4700 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
4701
4702 if (psa->psa_options & PSA_OPTION_DATALESS_IOPOLICY) {
4703 struct _iopol_param_t iop_param = {
4704 .iop_scope = IOPOL_SCOPE_PROCESS,
4705 .iop_iotype = IOPOL_TYPE_VFS_MATERIALIZE_DATALESS_FILES,
4706 .iop_policy = psa->psa_dataless_iopolicy,
4707 };
4708 error = iopolicysys_vfs_materialize_dataless_files(p, IOPOL_CMD_SET, iop_param.iop_scope,
4709 iop_param.iop_policy, &iop_param);
4710 }
4711 }
4712
4713 if (error == 0) {
4714 /* Apply the main thread qos */
4715 thread_t main_thread = imgp->ip_new_thread;
4716 task_set_main_thread_qos(new_task, main_thread);
4717 }
4718
4719 /*
4720 * Release any ports we kept around for binding to the new task
4721 * We need to release the rights even if the posix_spawn has failed.
4722 */
4723 if (imgp->ip_px_spa != NULL) {
4724 exec_port_actions_destroy(&port_actions);
4725 }
4726
4727 /*
4728 * We have to delay operations which might throw a signal until after
4729 * the signals have been unblocked; however, we want that to happen
4730 * after exec_resettextvp() so that the textvp is correct when they
4731 * fire.
4732 */
4733 if (error == 0) {
4734 error = process_signature(p, imgp);
4735
4736 /*
4737 * Pay for our earlier safety; deliver the delayed signals from
4738 * the incomplete spawn process now that it's complete.
4739 */
4740 if (imgp != NULL && spawn_no_exec && (p->p_lflag & P_LTRACED)) {
4741 psignal_vfork(p, proc_task(p), imgp->ip_new_thread, SIGTRAP);
4742 }
4743
4744 if (error == 0 && !spawn_no_exec) {
4745 KDBG(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXEC),
4746 proc_getpid(p));
4747 }
4748 }
4749
4750 if (spawn_no_exec) {
4751 /* flag the 'fork' has occurred */
4752 proc_knote(p->p_pptr, NOTE_FORK | proc_getpid(p));
4753 }
4754
4755 /* flag exec has occurred, notify only if it has not failed due to FP Key error */
4756 if (!error && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
4757 proc_knote(p, NOTE_EXEC);
4758 }
4759
4760 if (imgp != NULL) {
4761 uthread_set_exec_data(current_uthread(), NULL);
4762 if (imgp->ip_vp) {
4763 vnode_put(imgp->ip_vp);
4764 }
4765 if (imgp->ip_scriptvp) {
4766 vnode_put(imgp->ip_scriptvp);
4767 }
4768 if (imgp->ip_strings) {
4769 execargs_free(imgp);
4770 }
4771 if (imgp->ip_free_map) {
4772 /* Free the map after dropping iocount on vnode to avoid deadlock */
4773 vm_map_deallocate(imgp->ip_free_map);
4774 }
4775 kfree_data(imgp->ip_px_sfa,
4776 px_args.file_actions_size);
4777 kfree_data(imgp->ip_px_spa,
4778 px_args.port_actions_size);
4779 #if CONFIG_PERSONAS
4780 kfree_data(imgp->ip_px_persona,
4781 px_args.persona_info_size);
4782 #endif
4783 kfree_data(imgp->ip_px_pcred_info,
4784 px_args.posix_cred_info_size);
4785
4786 if (subsystem_root_path != NULL) {
4787 zfree(ZV_NAMEI, subsystem_root_path);
4788 }
4789 #if CONFIG_MACF
4790 struct ip_px_smpx_s *px_s = &imgp->ip_px_smpx;
4791 kfree_data(px_s->array, px_args.mac_extensions_size);
4792 kfree_data(px_s->data, (vm_size_t)px_s->datalen);
4793
4794 if (imgp->ip_execlabelp) {
4795 mac_cred_label_free(imgp->ip_execlabelp);
4796 imgp->ip_execlabelp = NULL;
4797 }
4798 if (imgp->ip_scriptlabelp) {
4799 mac_vnode_label_free(imgp->ip_scriptlabelp);
4800 imgp->ip_scriptlabelp = NULL;
4801 }
4802 if (imgp->ip_cs_error != OS_REASON_NULL) {
4803 os_reason_free(imgp->ip_cs_error);
4804 imgp->ip_cs_error = OS_REASON_NULL;
4805 }
4806 if (imgp->ip_inherited_shared_region_id != NULL) {
4807 kfree_data(imgp->ip_inherited_shared_region_id,
4808 strlen(imgp->ip_inherited_shared_region_id) + 1);
4809 imgp->ip_inherited_shared_region_id = NULL;
4810 }
4811 #endif
4812 }
4813
4814 #if CONFIG_DTRACE
4815 if (spawn_no_exec) {
4816 /*
4817 * In the original DTrace reference implementation,
4818 * posix_spawn() was a libc routine that just
4819 * did vfork(2) then exec(2). Thus the proc::: probes
4820 * are very fork/exec oriented. The details of this
4821 * in-kernel implementation of posix_spawn() is different
4822 * (while producing the same process-observable effects)
4823 * particularly w.r.t. errors, and which thread/process
4824 * is constructing what on behalf of whom.
4825 */
4826 if (error) {
4827 DTRACE_PROC1(spawn__failure, int, error);
4828 } else {
4829 DTRACE_PROC(spawn__success);
4830 /*
4831 * Some DTrace scripts, e.g. newproc.d in
4832 * /usr/bin, rely on the the 'exec-success'
4833 * probe being fired in the child after the
4834 * new process image has been constructed
4835 * in order to determine the associated pid.
4836 *
4837 * So, even though the parent built the image
4838 * here, for compatibility, mark the new thread
4839 * so 'exec-success' fires on it as it leaves
4840 * the kernel.
4841 */
4842 dtrace_thread_didexec(imgp->ip_new_thread);
4843 }
4844 } else {
4845 if (error) {
4846 DTRACE_PROC1(exec__failure, int, error);
4847 } else {
4848 dtrace_thread_didexec(imgp->ip_new_thread);
4849 }
4850 }
4851
4852 if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
4853 (*dtrace_proc_waitfor_hook)(p);
4854 }
4855 #endif
4856
4857 #if CONFIG_AUDIT
4858 if (!error && AUDIT_ENABLED() && p) {
4859 /* Add the CDHash of the new process to the audit record */
4860 uint8_t *cdhash = cs_get_cdhash(p);
4861 if (cdhash) {
4862 AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
4863 }
4864 }
4865 #endif
4866
4867 /* terminate the new task if exec failed */
4868 if (new_task != NULL && task_is_exec_copy(new_task)) {
4869 task_terminate_internal(new_task);
4870 }
4871
4872 if (exec_failure_reason && !spawn_no_exec) {
4873 psignal_with_reason(p, SIGKILL, exec_failure_reason);
4874 exec_failure_reason = NULL;
4875 }
4876
4877 /* Return to both the parent and the child? */
4878 if (imgp != NULL && spawn_no_exec) {
4879 /*
4880 * If the parent wants the pid, copy it out
4881 */
4882 if (error == 0 && pid != USER_ADDR_NULL) {
4883 _Static_assert(sizeof(pid_t) == 4, "posix_spawn() assumes a 32-bit pid_t");
4884 bool aligned = (pid & 3) == 0;
4885 if (aligned) {
4886 (void)copyout_atomic32(proc_getpid(p), pid);
4887 } else {
4888 (void)suword(pid, proc_getpid(p));
4889 }
4890 }
4891 retval[0] = error;
4892
4893 /*
4894 * If we had an error, perform an internal reap ; this is
4895 * entirely safe, as we have a real process backing us.
4896 */
4897 if (error) {
4898 proc_list_lock();
4899 p->p_listflag |= P_LIST_DEADPARENT;
4900 proc_list_unlock();
4901 proc_lock(p);
4902 /* make sure no one else has killed it off... */
4903 if (p->p_stat != SZOMB && p->exit_thread == NULL) {
4904 p->exit_thread = current_thread();
4905 p->p_posix_spawn_failed = true;
4906 proc_unlock(p);
4907 exit1(p, 1, (int *)NULL);
4908 } else {
4909 /* someone is doing it for us; just skip it */
4910 proc_unlock(p);
4911 }
4912 }
4913 }
4914
4915 /*
4916 * Do not terminate the current task, if proc_exec_switch_task did not
4917 * switch the tasks, terminating the current task without the switch would
4918 * result in loosing the SIGKILL status.
4919 */
4920 if (task_did_exec(old_task)) {
4921 /* Terminate the current task, since exec will start in new task */
4922 task_terminate_internal(old_task);
4923 }
4924
4925 /* Release the thread ref returned by cloneproc/fork1 */
4926 if (imgp != NULL && imgp->ip_new_thread) {
4927 /* clear the exec complete flag if there is an error before point of no-return */
4928 uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
4929 if (!spawn_no_exec && !exec_done && error != 0) {
4930 clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
4931 }
4932 /* wake up the new thread */
4933 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
4934 thread_deallocate(imgp->ip_new_thread);
4935 imgp->ip_new_thread = NULL;
4936 }
4937
4938 /* Release the ref returned by cloneproc/fork1 */
4939 if (new_task) {
4940 task_deallocate(new_task);
4941 new_task = NULL;
4942 }
4943
4944 if (should_release_proc_ref) {
4945 proc_rele(p);
4946 }
4947
4948 kfree_type(typeof(*__spawn_data), __spawn_data);
4949
4950 if (inherit != NULL) {
4951 ipc_importance_release(inherit);
4952 }
4953
4954 #if CONFIG_EXCLAVES
4955 if (task_conclave_id != NULL) {
4956 kfree_data(task_conclave_id, MAXCONCLAVENAME);
4957 }
4958 #endif
4959
4960 assert(spawn_no_exec || exec_failure_reason == NULL);
4961 return error;
4962 }
4963
4964 /*
4965 * proc_exec_switch_task
4966 *
4967 * Parameters: old_proc proc before exec
4968 * new_proc proc after exec
4969 * old_task task before exec
4970 * new_task task after exec
4971 * imgp image params
4972 * inherit resulting importance linkage
4973 *
4974 * Returns: proc.
4975 *
4976 * Note: The function will switch proc in pid hash from old proc to new proc.
4977 * The switch needs to happen after draining all proc refs and inside
4978 * a proc list lock. In the case of failure to switch the proc, which
4979 * might happen if the process received a SIGKILL or jetsam killed it,
4980 * it will make sure that the new tasks terminates. User proc ref returned
4981 * to caller.
4982 *
4983 * This function is called after point of no return, in the case
4984 * failure to switch, it will terminate the new task and swallow the
4985 * error and let the terminated process complete exec and die.
4986 */
4987 proc_t
proc_exec_switch_task(proc_t old_proc,proc_t new_proc,task_t old_task,task_t new_task,struct image_params * imgp,void ** inherit)4988 proc_exec_switch_task(proc_t old_proc, proc_t new_proc, task_t old_task, task_t new_task, struct image_params *imgp, void **inherit)
4989 {
4990 boolean_t task_active;
4991 boolean_t proc_active;
4992 boolean_t thread_active;
4993 boolean_t reparent_traced_child = FALSE;
4994 thread_t old_thread = current_thread();
4995 thread_t new_thread = imgp->ip_new_thread;
4996
4997 thread_set_exec_promotion(old_thread);
4998 old_proc = proc_refdrain_will_exec(old_proc);
4999
5000 new_proc = proc_refdrain_will_exec(new_proc);
5001 /* extra proc ref returned to the caller */
5002
5003 assert(get_threadtask(new_thread) == new_task);
5004 task_active = task_is_active(new_task);
5005 proc_active = !(old_proc->p_lflag & P_LEXIT);
5006
5007 /* Check if the current thread is not aborted due to SIGKILL */
5008 thread_active = thread_is_active(old_thread);
5009
5010 /*
5011 * Do not switch the proc if the new task or proc is already terminated
5012 * as a result of error in exec past point of no return
5013 */
5014 if (proc_active && task_active && thread_active) {
5015 uthread_t new_uthread = get_bsdthread_info(new_thread);
5016 uthread_t old_uthread = current_uthread();
5017
5018 /* Clear dispatchqueue and workloop ast offset */
5019 new_proc->p_dispatchqueue_offset = 0;
5020 new_proc->p_dispatchqueue_serialno_offset = 0;
5021 new_proc->p_dispatchqueue_label_offset = 0;
5022 new_proc->p_return_to_kernel_offset = 0;
5023 new_proc->p_pthread_wq_quantum_offset = 0;
5024
5025 /* If old_proc is session leader, change the leader to new proc */
5026 session_replace_leader(old_proc, new_proc);
5027
5028 proc_lock(old_proc);
5029
5030 /* Copy the signal state, dtrace state and set bsd ast on new thread */
5031 act_set_astbsd(new_thread);
5032 new_uthread->uu_siglist |= old_uthread->uu_siglist;
5033 new_uthread->uu_siglist |= old_proc->p_siglist;
5034 new_uthread->uu_sigwait = old_uthread->uu_sigwait;
5035 new_uthread->uu_sigmask = old_uthread->uu_sigmask;
5036 new_uthread->uu_oldmask = old_uthread->uu_oldmask;
5037 new_uthread->uu_exit_reason = old_uthread->uu_exit_reason;
5038 #if CONFIG_DTRACE
5039 new_uthread->t_dtrace_sig = old_uthread->t_dtrace_sig;
5040 new_uthread->t_dtrace_stop = old_uthread->t_dtrace_stop;
5041 new_uthread->t_dtrace_resumepid = old_uthread->t_dtrace_resumepid;
5042 assert(new_uthread->t_dtrace_scratch == NULL);
5043 new_uthread->t_dtrace_scratch = old_uthread->t_dtrace_scratch;
5044
5045 old_uthread->t_dtrace_sig = 0;
5046 old_uthread->t_dtrace_stop = 0;
5047 old_uthread->t_dtrace_resumepid = 0;
5048 old_uthread->t_dtrace_scratch = NULL;
5049 #endif
5050
5051 #if CONFIG_PROC_UDATA_STORAGE
5052 new_proc->p_user_data = old_proc->p_user_data;
5053 #endif /* CONFIG_PROC_UDATA_STORAGE */
5054
5055 /* Copy the resource accounting info */
5056 thread_copy_resource_info(new_thread, current_thread());
5057
5058 /* Clear the exit reason and signal state on old thread */
5059 old_uthread->uu_exit_reason = NULL;
5060 old_uthread->uu_siglist = 0;
5061
5062 task_set_did_exec_flag(old_task);
5063 task_clear_exec_copy_flag(new_task);
5064
5065 task_copy_fields_for_exec(new_task, old_task);
5066
5067 /*
5068 * Need to transfer pending watch port boosts to the new task
5069 * while still making sure that the old task remains in the
5070 * importance linkage. Create an importance linkage from old task
5071 * to new task, then switch the task importance base of old task
5072 * and new task. After the switch the port watch boost will be
5073 * boosting the new task and new task will be donating importance
5074 * to old task.
5075 */
5076 *inherit = ipc_importance_exec_switch_task(old_task, new_task);
5077
5078 /* Transfer parent's ptrace state to child */
5079 new_proc->p_lflag &= ~(P_LTRACED | P_LSIGEXC | P_LNOATTACH);
5080 new_proc->p_lflag |= (old_proc->p_lflag & (P_LTRACED | P_LSIGEXC | P_LNOATTACH));
5081 new_proc->p_oppid = old_proc->p_oppid;
5082
5083 if (old_proc->p_pptr != new_proc->p_pptr) {
5084 reparent_traced_child = TRUE;
5085 new_proc->p_lflag |= P_LTRACE_WAIT;
5086 }
5087
5088 proc_unlock(old_proc);
5089
5090 /* Update the list of proc knotes */
5091 proc_transfer_knotes(old_proc, new_proc);
5092
5093 /* Update the proc interval timers */
5094 proc_inherit_itimers(old_proc, new_proc);
5095
5096 proc_list_lock();
5097
5098 /* Insert the new proc in child list of parent proc */
5099 p_reparentallchildren(old_proc, new_proc);
5100
5101 /* Switch proc in pid hash */
5102 phash_replace_locked(old_proc, new_proc);
5103
5104 /* Transfer the shadow flag to old proc */
5105 os_atomic_andnot(&new_proc->p_refcount, P_REF_SHADOW, relaxed);
5106 os_atomic_or(&old_proc->p_refcount, P_REF_SHADOW, relaxed);
5107
5108 /* Change init proc if launchd exec */
5109 if (old_proc == initproc) {
5110 /* Take the ref on new proc after proc_refwake_did_exec */
5111 initproc = new_proc;
5112 /* Drop the proc ref on old proc */
5113 proc_rele(old_proc);
5114 }
5115
5116 proc_list_unlock();
5117 #if CONFIG_EXCLAVES
5118 if (task_inherit_conclave(old_task, new_task, imgp->ip_vp,
5119 (int64_t)imgp->ip_arch_offset) != KERN_SUCCESS) {
5120 task_terminate_internal(new_task);
5121 }
5122 #endif
5123 } else {
5124 task_terminate_internal(new_task);
5125 }
5126
5127 proc_refwake_did_exec(new_proc);
5128 proc_refwake_did_exec(old_proc);
5129
5130 /* Take a ref on initproc if it changed */
5131 if (new_proc == initproc) {
5132 initproc = proc_ref(new_proc, false);
5133 assert(initproc != PROC_NULL);
5134 }
5135
5136 thread_clear_exec_promotion(old_thread);
5137 proc_rele(old_proc);
5138
5139 if (reparent_traced_child) {
5140 proc_t pp = proc_parent(old_proc);
5141 assert(pp != PROC_NULL);
5142
5143 proc_reparentlocked(new_proc, pp, 1, 0);
5144 proc_rele(pp);
5145
5146 proc_lock(new_proc);
5147 new_proc->p_lflag &= ~P_LTRACE_WAIT;
5148 proc_unlock(new_proc);
5149 }
5150
5151 return new_proc;
5152 }
5153
5154 /*
5155 * execve
5156 *
5157 * Parameters: uap->fname File name to exec
5158 * uap->argp Argument list
5159 * uap->envp Environment list
5160 *
5161 * Returns: 0 Success
5162 * __mac_execve:EINVAL Invalid argument
5163 * __mac_execve:ENOTSUP Invalid argument
5164 * __mac_execve:EACCES Permission denied
5165 * __mac_execve:EINTR Interrupted function
5166 * __mac_execve:ENOMEM Not enough space
5167 * __mac_execve:EFAULT Bad address
5168 * __mac_execve:ENAMETOOLONG Filename too long
5169 * __mac_execve:ENOEXEC Executable file format error
5170 * __mac_execve:ETXTBSY Text file busy [misuse of error code]
5171 * __mac_execve:???
5172 *
5173 * TODO: Dynamic linker header address on stack is copied via suword()
5174 */
5175 /* ARGSUSED */
5176 int
execve(proc_t p,struct execve_args * uap,int32_t * retval)5177 execve(proc_t p, struct execve_args *uap, int32_t *retval)
5178 {
5179 struct __mac_execve_args muap;
5180 int err;
5181
5182 memoryshot(DBG_VM_EXECVE, DBG_FUNC_NONE);
5183
5184 muap.fname = uap->fname;
5185 muap.argp = uap->argp;
5186 muap.envp = uap->envp;
5187 muap.mac_p = USER_ADDR_NULL;
5188 err = __mac_execve(p, &muap, retval);
5189
5190 return err;
5191 }
5192
5193 /*
5194 * __mac_execve
5195 *
5196 * Parameters: uap->fname File name to exec
5197 * uap->argp Argument list
5198 * uap->envp Environment list
5199 * uap->mac_p MAC label supplied by caller
5200 *
5201 * Returns: 0 Success
5202 * EINVAL Invalid argument
5203 * ENOTSUP Not supported
5204 * ENOEXEC Executable file format error
5205 * exec_activate_image:EINVAL Invalid argument
5206 * exec_activate_image:EACCES Permission denied
5207 * exec_activate_image:EINTR Interrupted function
5208 * exec_activate_image:ENOMEM Not enough space
5209 * exec_activate_image:EFAULT Bad address
5210 * exec_activate_image:ENAMETOOLONG Filename too long
5211 * exec_activate_image:ENOEXEC Executable file format error
5212 * exec_activate_image:ETXTBSY Text file busy [misuse of error code]
5213 * exec_activate_image:EBADEXEC The executable is corrupt/unknown
5214 * exec_activate_image:???
5215 * mac_execve_enter:???
5216 *
5217 * TODO: Dynamic linker header address on stack is copied via suword()
5218 */
5219 int
__mac_execve(proc_t p,struct __mac_execve_args * uap,int32_t * retval __unused)5220 __mac_execve(proc_t p, struct __mac_execve_args *uap, int32_t *retval __unused)
5221 {
5222 struct image_params *imgp = NULL;
5223 struct vnode_attr *vap = NULL;
5224 struct vnode_attr *origvap = NULL;
5225 int error;
5226 int is_64 = IS_64BIT_PROCESS(p);
5227 struct vfs_context context;
5228 struct uthread *uthread = NULL;
5229 task_t old_task = current_task();
5230 task_t new_task = NULL;
5231 boolean_t should_release_proc_ref = FALSE;
5232 boolean_t exec_done = FALSE;
5233 void *inherit = NULL;
5234 struct {
5235 struct image_params imgp;
5236 struct vnode_attr va;
5237 struct vnode_attr origva;
5238 } *__execve_data;
5239
5240 /* Allocate a big chunk for locals instead of using stack since these
5241 * structures a pretty big.
5242 */
5243 __execve_data = kalloc_type(typeof(*__execve_data), Z_WAITOK | Z_ZERO);
5244 if (__execve_data == NULL) {
5245 error = ENOMEM;
5246 goto exit_with_error;
5247 }
5248 imgp = &__execve_data->imgp;
5249 vap = &__execve_data->va;
5250 origvap = &__execve_data->origva;
5251
5252 /* Initialize the common data in the image_params structure */
5253 imgp->ip_user_fname = uap->fname;
5254 imgp->ip_user_argv = uap->argp;
5255 imgp->ip_user_envv = uap->envp;
5256 imgp->ip_vattr = vap;
5257 imgp->ip_origvattr = origvap;
5258 imgp->ip_vfs_context = &context;
5259 imgp->ip_flags = (is_64 ? IMGPF_WAS_64BIT_ADDR : IMGPF_NONE) | ((p->p_flag & P_DISABLE_ASLR) ? IMGPF_DISABLE_ASLR : IMGPF_NONE);
5260 imgp->ip_seg = (is_64 ? UIO_USERSPACE64 : UIO_USERSPACE32);
5261 imgp->ip_mac_return = 0;
5262 imgp->ip_cs_error = OS_REASON_NULL;
5263 imgp->ip_simulator_binary = IMGPF_SB_DEFAULT;
5264 imgp->ip_subsystem_root_path = NULL;
5265 uthread_set_exec_data(current_uthread(), imgp);
5266
5267 #if CONFIG_MACF
5268 if (uap->mac_p != USER_ADDR_NULL) {
5269 error = mac_execve_enter(uap->mac_p, imgp);
5270 if (error) {
5271 goto exit_with_error;
5272 }
5273 }
5274 #endif
5275 uthread = current_uthread();
5276 {
5277 imgp->ip_flags |= IMGPF_EXEC;
5278
5279 /* Adjust the user proc count */
5280 (void)chgproccnt(kauth_getruid(), 1);
5281 /*
5282 * For execve case, create a new proc, task and thread
5283 * but don't make the proc visible to userland. After
5284 * image activation, the new proc would take place of
5285 * the old proc in pid hash and other lists that make
5286 * the proc visible to the system.
5287 */
5288 imgp->ip_new_thread = cloneproc(old_task, NULL, p, CLONEPROC_EXEC);
5289 /* task and thread ref returned by cloneproc */
5290 if (imgp->ip_new_thread == NULL) {
5291 (void)chgproccnt(kauth_getruid(), -1);
5292 error = ENOMEM;
5293 goto exit_with_error;
5294 }
5295
5296 new_task = get_threadtask(imgp->ip_new_thread);
5297 }
5298
5299 p = (proc_t)get_bsdthreadtask_info(imgp->ip_new_thread);
5300
5301 context.vc_thread = imgp->ip_new_thread;
5302 context.vc_ucred = kauth_cred_proc_ref(p); /* XXX must NOT be kauth_cred_get() */
5303
5304 imgp->ip_subsystem_root_path = p->p_subsystem_root_path;
5305
5306 proc_transend(p, 0);
5307 proc_signalend(p, 0);
5308
5309
5310 /*
5311 * Activate the image.
5312 * Warning: If activation failed after point of no return, it returns error
5313 * as 0 and pretends the call succeeded.
5314 */
5315 error = exec_activate_image(imgp);
5316 /* thread and task ref returned for vfexec case */
5317
5318 if (imgp->ip_new_thread != NULL) {
5319 /*
5320 * task reference might be returned by exec_activate_image
5321 * for vfexec.
5322 */
5323 new_task = get_threadtask(imgp->ip_new_thread);
5324 #if defined(HAS_APPLE_PAC)
5325 ml_task_set_disable_user_jop(new_task, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5326 ml_thread_set_disable_user_jop(imgp->ip_new_thread, imgp->ip_flags & IMGPF_NOJOP ? TRUE : FALSE);
5327 #endif
5328 }
5329
5330 if (!error) {
5331 p = proc_exec_switch_task(current_proc(), p, old_task, new_task, imgp, &inherit);
5332 /* proc ref returned */
5333 should_release_proc_ref = TRUE;
5334 }
5335
5336 kauth_cred_unref(&context.vc_ucred);
5337
5338 if (!error) {
5339 exec_done = TRUE;
5340 assert(imgp->ip_new_thread != NULL);
5341
5342 exec_resettextvp(p, imgp);
5343 /*
5344 * Enable new task IPC access if exec_activate_image() returned an
5345 * active task. (Checks active bit in ipc_task_enable() under lock).
5346 * Must enable after resettextvp so that task port policies are not evaluated
5347 * until the csblob in the textvp is accurately reflected.
5348 */
5349 ipc_task_enable(new_task);
5350 error = process_signature(p, imgp);
5351 }
5352
5353 #if defined(HAS_APPLE_PAC)
5354 if (imgp->ip_new_thread && !error) {
5355 ml_task_set_jop_pid_from_shared_region(new_task, imgp->ip_flags & IMGPF_NOJOP);
5356 ml_thread_set_jop_pid(imgp->ip_new_thread, new_task);
5357 }
5358 #endif /* defined(HAS_APPLE_PAC) */
5359
5360 /* flag exec has occurred, notify only if it has not failed due to FP Key error */
5361 if (exec_done && ((p->p_lflag & P_LTERM_DECRYPTFAIL) == 0)) {
5362 proc_knote(p, NOTE_EXEC);
5363 }
5364
5365 if (imgp->ip_vp != NULLVP) {
5366 vnode_put(imgp->ip_vp);
5367 }
5368 if (imgp->ip_scriptvp != NULLVP) {
5369 vnode_put(imgp->ip_scriptvp);
5370 }
5371 if (imgp->ip_free_map) {
5372 /* Free the map after dropping iocount on vnode to avoid deadlock */
5373 vm_map_deallocate(imgp->ip_free_map);
5374 }
5375 if (imgp->ip_strings) {
5376 execargs_free(imgp);
5377 }
5378 #if CONFIG_MACF
5379 if (imgp->ip_execlabelp) {
5380 mac_cred_label_free(imgp->ip_execlabelp);
5381 imgp->ip_execlabelp = NULL;
5382 }
5383 if (imgp->ip_scriptlabelp) {
5384 mac_vnode_label_free(imgp->ip_scriptlabelp);
5385 imgp->ip_scriptlabelp = NULL;
5386 }
5387 #endif
5388 if (imgp->ip_cs_error != OS_REASON_NULL) {
5389 os_reason_free(imgp->ip_cs_error);
5390 imgp->ip_cs_error = OS_REASON_NULL;
5391 }
5392
5393 if (!error) {
5394 /*
5395 * We need to initialize the bank context behind the protection of
5396 * the proc_trans lock to prevent a race with exit. We can't do this during
5397 * exec_activate_image because task_bank_init checks entitlements that
5398 * aren't loaded until subsequent calls (including exec_resettextvp).
5399 */
5400 error = proc_transstart(p, 0, 0);
5401 }
5402
5403 if (!error) {
5404 task_bank_init(new_task);
5405 proc_transend(p, 0);
5406
5407 // Don't inherit crash behavior across exec, but preserve crash behavior from bootargs
5408 p->p_crash_behavior = 0;
5409 p->p_crash_behavior_deadline = 0;
5410 #if (DEVELOPMENT || DEBUG)
5411 set_crash_behavior_from_bootarg(p);
5412 #endif
5413
5414 #if __arm64__
5415 proc_footprint_entitlement_hacks(p, new_task);
5416 #endif /* __arm64__ */
5417
5418 #if XNU_TARGET_OS_OSX
5419 if (IOTaskHasEntitlement(new_task, SINGLE_JIT_ENTITLEMENT)) {
5420 vm_map_single_jit(get_task_map(new_task));
5421 }
5422 #endif /* XNU_TARGET_OS_OSX */
5423
5424 /* Sever any extant thread affinity */
5425 thread_affinity_exec(current_thread());
5426
5427 /* Inherit task role from old task to new task for exec */
5428 proc_inherit_task_role(new_task, old_task);
5429
5430 thread_t main_thread = imgp->ip_new_thread;
5431
5432 task_set_main_thread_qos(new_task, main_thread);
5433
5434 #if __has_feature(ptrauth_calls)
5435 task_set_pac_exception_fatal_flag(new_task);
5436 #endif /* __has_feature(ptrauth_calls) */
5437 task_set_jit_exception_fatal_flag(new_task);
5438
5439 #if CONFIG_ARCADE
5440 /*
5441 * Check to see if we need to trigger an arcade upcall AST now
5442 * that the vnode has been reset on the task.
5443 */
5444 arcade_prepare(new_task, imgp->ip_new_thread);
5445 #endif /* CONFIG_ARCADE */
5446
5447 proc_apply_jit_and_vm_policies(imgp, p, new_task);
5448
5449 if (vm_darkwake_mode == TRUE) {
5450 /*
5451 * This process is being launched when the system
5452 * is in darkwake. So mark it specially. This will
5453 * cause all its pages to be entered in the background Q.
5454 */
5455 task_set_darkwake_mode(new_task, vm_darkwake_mode);
5456 }
5457
5458 #if CONFIG_DTRACE
5459 dtrace_thread_didexec(imgp->ip_new_thread);
5460
5461 if ((dtrace_proc_waitfor_hook = dtrace_proc_waitfor_exec_ptr) != NULL) {
5462 (*dtrace_proc_waitfor_hook)(p);
5463 }
5464 #endif
5465
5466 #if CONFIG_AUDIT
5467 if (!error && AUDIT_ENABLED() && p) {
5468 /* Add the CDHash of the new process to the audit record */
5469 uint8_t *cdhash = cs_get_cdhash(p);
5470 if (cdhash) {
5471 AUDIT_ARG(data, cdhash, sizeof(uint8_t), CS_CDHASH_LEN);
5472 }
5473 }
5474 #endif
5475 } else {
5476 DTRACE_PROC1(exec__failure, int, error);
5477 }
5478
5479 exit_with_error:
5480
5481 /* terminate the new task it if exec failed */
5482 if (new_task != NULL && task_is_exec_copy(new_task)) {
5483 task_terminate_internal(new_task);
5484 }
5485
5486 if (imgp != NULL) {
5487 /* Clear the initial wait on the thread transferring watchports */
5488 if (imgp->ip_new_thread) {
5489 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), TCRW_CLEAR_INITIAL_WAIT);
5490 }
5491
5492 /* Transfer the watchport boost to new task */
5493 if (!error) {
5494 task_transfer_turnstile_watchports(old_task,
5495 new_task, imgp->ip_new_thread);
5496 }
5497 /*
5498 * Do not terminate the current task, if proc_exec_switch_task did not
5499 * switch the tasks, terminating the current task without the switch would
5500 * result in loosing the SIGKILL status.
5501 */
5502 if (task_did_exec(old_task)) {
5503 /* Terminate the current task, since exec will start in new task */
5504 task_terminate_internal(old_task);
5505 }
5506
5507 /* Release the thread ref returned by cloneproc */
5508 if (imgp->ip_new_thread) {
5509 /* clear the exec complete flag if there is an error before point of no-return */
5510 uint32_t clearwait_flags = TCRW_CLEAR_FINAL_WAIT;
5511 if (!exec_done && error != 0) {
5512 clearwait_flags |= TCRW_CLEAR_EXEC_COMPLETE;
5513 }
5514 /* wake up the new exec thread */
5515 task_clear_return_wait(get_threadtask(imgp->ip_new_thread), clearwait_flags);
5516 thread_deallocate(imgp->ip_new_thread);
5517 imgp->ip_new_thread = NULL;
5518 }
5519 }
5520
5521 /* Release the ref returned by fork_create_child */
5522 if (new_task) {
5523 task_deallocate(new_task);
5524 new_task = NULL;
5525 }
5526
5527 if (should_release_proc_ref) {
5528 proc_rele(p);
5529 }
5530
5531 uthread_set_exec_data(current_uthread(), NULL);
5532 kfree_type(typeof(*__execve_data), __execve_data);
5533
5534 if (inherit != NULL) {
5535 ipc_importance_release(inherit);
5536 }
5537
5538 return error;
5539 }
5540
5541
5542 /*
5543 * copyinptr
5544 *
5545 * Description: Copy a pointer in from user space to a user_addr_t in kernel
5546 * space, based on 32/64 bitness of the user space
5547 *
5548 * Parameters: froma User space address
5549 * toptr Address of kernel space user_addr_t
5550 * ptr_size 4/8, based on 'froma' address space
5551 *
5552 * Returns: 0 Success
5553 * EFAULT Bad 'froma'
5554 *
5555 * Implicit returns:
5556 * *ptr_size Modified
5557 */
5558 static int
copyinptr(user_addr_t froma,user_addr_t * toptr,int ptr_size)5559 copyinptr(user_addr_t froma, user_addr_t *toptr, int ptr_size)
5560 {
5561 int error;
5562
5563 if (ptr_size == 4) {
5564 /* 64 bit value containing 32 bit address */
5565 unsigned int i = 0;
5566
5567 error = copyin(froma, &i, 4);
5568 *toptr = CAST_USER_ADDR_T(i); /* SAFE */
5569 } else {
5570 error = copyin(froma, toptr, 8);
5571 }
5572 return error;
5573 }
5574
5575
5576 /*
5577 * copyoutptr
5578 *
5579 * Description: Copy a pointer out from a user_addr_t in kernel space to
5580 * user space, based on 32/64 bitness of the user space
5581 *
5582 * Parameters: ua User space address to copy to
5583 * ptr Address of kernel space user_addr_t
5584 * ptr_size 4/8, based on 'ua' address space
5585 *
5586 * Returns: 0 Success
5587 * EFAULT Bad 'ua'
5588 *
5589 */
5590 static int
copyoutptr(user_addr_t ua,user_addr_t ptr,int ptr_size)5591 copyoutptr(user_addr_t ua, user_addr_t ptr, int ptr_size)
5592 {
5593 int error;
5594
5595 if (ptr_size == 4) {
5596 /* 64 bit value containing 32 bit address */
5597 unsigned int i = CAST_DOWN_EXPLICIT(unsigned int, ua); /* SAFE */
5598
5599 error = copyout(&i, ptr, 4);
5600 } else {
5601 error = copyout(&ua, ptr, 8);
5602 }
5603 return error;
5604 }
5605
5606
5607 /*
5608 * exec_copyout_strings
5609 *
5610 * Copy out the strings segment to user space. The strings segment is put
5611 * on a preinitialized stack frame.
5612 *
5613 * Parameters: struct image_params * the image parameter block
5614 * int * a pointer to the stack offset variable
5615 *
5616 * Returns: 0 Success
5617 * !0 Faiure: errno
5618 *
5619 * Implicit returns:
5620 * (*stackp) The stack offset, modified
5621 *
5622 * Note: The strings segment layout is backward, from the beginning
5623 * of the top of the stack to consume the minimal amount of
5624 * space possible; the returned stack pointer points to the
5625 * end of the area consumed (stacks grow downward).
5626 *
5627 * argc is an int; arg[i] are pointers; env[i] are pointers;
5628 * the 0's are (void *)NULL's
5629 *
5630 * The stack frame layout is:
5631 *
5632 * +-------------+ <- p->user_stack
5633 * | 16b |
5634 * +-------------+
5635 * | STRING AREA |
5636 * | : |
5637 * | : |
5638 * | : |
5639 * +- -- -- -- --+
5640 * | PATH AREA |
5641 * +-------------+
5642 * | 0 |
5643 * +-------------+
5644 * | applev[n] |
5645 * +-------------+
5646 * :
5647 * :
5648 * +-------------+
5649 * | applev[1] |
5650 * +-------------+
5651 * | exec_path / |
5652 * | applev[0] |
5653 * +-------------+
5654 * | 0 |
5655 * +-------------+
5656 * | env[n] |
5657 * +-------------+
5658 * :
5659 * :
5660 * +-------------+
5661 * | env[0] |
5662 * +-------------+
5663 * | 0 |
5664 * +-------------+
5665 * | arg[argc-1] |
5666 * +-------------+
5667 * :
5668 * :
5669 * +-------------+
5670 * | arg[0] |
5671 * +-------------+
5672 * | argc |
5673 * sp-> +-------------+
5674 *
5675 * Although technically a part of the STRING AREA, we treat the PATH AREA as
5676 * a separate entity. This allows us to align the beginning of the PATH AREA
5677 * to a pointer boundary so that the exec_path, env[i], and argv[i] pointers
5678 * which preceed it on the stack are properly aligned.
5679 */
5680 __attribute__((noinline))
5681 static int
exec_copyout_strings(struct image_params * imgp,user_addr_t * stackp)5682 exec_copyout_strings(struct image_params *imgp, user_addr_t *stackp)
5683 {
5684 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
5685 int ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5686 int ptr_area_size;
5687 void *ptr_buffer_start, *ptr_buffer;
5688 size_t string_size;
5689
5690 user_addr_t string_area; /* *argv[], *env[] */
5691 user_addr_t ptr_area; /* argv[], env[], applev[] */
5692 user_addr_t argc_area; /* argc */
5693 user_addr_t stack;
5694 int error;
5695
5696 unsigned i;
5697 struct copyout_desc {
5698 char *start_string;
5699 int count;
5700 #if CONFIG_DTRACE
5701 user_addr_t *dtrace_cookie;
5702 #endif
5703 boolean_t null_term;
5704 } descriptors[] = {
5705 {
5706 .start_string = imgp->ip_startargv,
5707 .count = imgp->ip_argc,
5708 #if CONFIG_DTRACE
5709 .dtrace_cookie = &p->p_dtrace_argv,
5710 #endif
5711 .null_term = TRUE
5712 },
5713 {
5714 .start_string = imgp->ip_endargv,
5715 .count = imgp->ip_envc,
5716 #if CONFIG_DTRACE
5717 .dtrace_cookie = &p->p_dtrace_envp,
5718 #endif
5719 .null_term = TRUE
5720 },
5721 {
5722 .start_string = imgp->ip_strings,
5723 .count = 1,
5724 #if CONFIG_DTRACE
5725 .dtrace_cookie = NULL,
5726 #endif
5727 .null_term = FALSE
5728 },
5729 {
5730 .start_string = imgp->ip_endenvv,
5731 .count = imgp->ip_applec - 1, /* exec_path handled above */
5732 #if CONFIG_DTRACE
5733 .dtrace_cookie = NULL,
5734 #endif
5735 .null_term = TRUE
5736 }
5737 };
5738
5739 stack = *stackp;
5740
5741 /*
5742 * All previous contributors to the string area
5743 * should have aligned their sub-area
5744 */
5745 if (imgp->ip_strspace % ptr_size != 0) {
5746 error = EINVAL;
5747 goto bad;
5748 }
5749
5750 /* Grow the stack down for the strings we've been building up */
5751 string_size = imgp->ip_strendp - imgp->ip_strings;
5752 stack -= string_size;
5753 string_area = stack;
5754
5755 /*
5756 * Need room for one pointer for each string, plus
5757 * one for the NULLs terminating the argv, envv, and apple areas.
5758 */
5759 ptr_area_size = (imgp->ip_argc + imgp->ip_envc + imgp->ip_applec + 3) * ptr_size;
5760 stack -= ptr_area_size;
5761 ptr_area = stack;
5762
5763 /* We'll construct all the pointer arrays in our string buffer,
5764 * which we already know is aligned properly, and ip_argspace
5765 * was used to verify we have enough space.
5766 */
5767 ptr_buffer_start = ptr_buffer = (void *)imgp->ip_strendp;
5768
5769 /*
5770 * Need room for pointer-aligned argc slot.
5771 */
5772 stack -= ptr_size;
5773 argc_area = stack;
5774
5775 /*
5776 * Record the size of the arguments area so that sysctl_procargs()
5777 * can return the argument area without having to parse the arguments.
5778 */
5779 proc_lock(p);
5780 p->p_argc = imgp->ip_argc;
5781 p->p_argslen = (int)(*stackp - string_area);
5782 proc_unlock(p);
5783
5784 /* Return the initial stack address: the location of argc */
5785 *stackp = stack;
5786
5787 /*
5788 * Copy out the entire strings area.
5789 */
5790 error = copyout(imgp->ip_strings, string_area,
5791 string_size);
5792 if (error) {
5793 goto bad;
5794 }
5795
5796 for (i = 0; i < sizeof(descriptors) / sizeof(descriptors[0]); i++) {
5797 char *cur_string = descriptors[i].start_string;
5798 int j;
5799
5800 #if CONFIG_DTRACE
5801 if (descriptors[i].dtrace_cookie) {
5802 proc_lock(p);
5803 *descriptors[i].dtrace_cookie = ptr_area + ((uintptr_t)ptr_buffer - (uintptr_t)ptr_buffer_start); /* dtrace convenience */
5804 proc_unlock(p);
5805 }
5806 #endif /* CONFIG_DTRACE */
5807
5808 /*
5809 * For each segment (argv, envv, applev), copy as many pointers as requested
5810 * to our pointer buffer.
5811 */
5812 for (j = 0; j < descriptors[i].count; j++) {
5813 user_addr_t cur_address = string_area + (cur_string - imgp->ip_strings);
5814
5815 /* Copy out the pointer to the current string. Alignment has been verified */
5816 if (ptr_size == 8) {
5817 *(uint64_t *)ptr_buffer = (uint64_t)cur_address;
5818 } else {
5819 *(uint32_t *)ptr_buffer = (uint32_t)cur_address;
5820 }
5821
5822 ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5823 cur_string += strlen(cur_string) + 1; /* Only a NUL between strings in the same area */
5824 }
5825
5826 if (descriptors[i].null_term) {
5827 if (ptr_size == 8) {
5828 *(uint64_t *)ptr_buffer = 0ULL;
5829 } else {
5830 *(uint32_t *)ptr_buffer = 0;
5831 }
5832
5833 ptr_buffer = (void *)((uintptr_t)ptr_buffer + ptr_size);
5834 }
5835 }
5836
5837 /*
5838 * Copy out all our pointer arrays in bulk.
5839 */
5840 error = copyout(ptr_buffer_start, ptr_area,
5841 ptr_area_size);
5842 if (error) {
5843 goto bad;
5844 }
5845
5846 /* argc (int32, stored in a ptr_size area) */
5847 error = copyoutptr((user_addr_t)imgp->ip_argc, argc_area, ptr_size);
5848 if (error) {
5849 goto bad;
5850 }
5851
5852 bad:
5853 return error;
5854 }
5855
5856
5857 /*
5858 * exec_extract_strings
5859 *
5860 * Copy arguments and environment from user space into work area; we may
5861 * have already copied some early arguments into the work area, and if
5862 * so, any arguments opied in are appended to those already there.
5863 * This function is the primary manipulator of ip_argspace, since
5864 * these are the arguments the client of execve(2) knows about. After
5865 * each argv[]/envv[] string is copied, we charge the string length
5866 * and argv[]/envv[] pointer slot to ip_argspace, so that we can
5867 * full preflight the arg list size.
5868 *
5869 * Parameters: struct image_params * the image parameter block
5870 *
5871 * Returns: 0 Success
5872 * !0 Failure: errno
5873 *
5874 * Implicit returns;
5875 * (imgp->ip_argc) Count of arguments, updated
5876 * (imgp->ip_envc) Count of environment strings, updated
5877 * (imgp->ip_argspace) Count of remaining of NCARGS
5878 * (imgp->ip_interp_buffer) Interpreter and args (mutated in place)
5879 *
5880 *
5881 * Note: The argument and environment vectors are user space pointers
5882 * to arrays of user space pointers.
5883 */
5884 __attribute__((noinline))
5885 static int
exec_extract_strings(struct image_params * imgp)5886 exec_extract_strings(struct image_params *imgp)
5887 {
5888 int error = 0;
5889 int ptr_size = (imgp->ip_flags & IMGPF_WAS_64BIT_ADDR) ? 8 : 4;
5890 int new_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
5891 user_addr_t argv = imgp->ip_user_argv;
5892 user_addr_t envv = imgp->ip_user_envv;
5893
5894 /*
5895 * Adjust space reserved for the path name by however much padding it
5896 * needs. Doing this here since we didn't know if this would be a 32-
5897 * or 64-bit process back in exec_save_path.
5898 */
5899 while (imgp->ip_strspace % new_ptr_size != 0) {
5900 *imgp->ip_strendp++ = '\0';
5901 imgp->ip_strspace--;
5902 /* imgp->ip_argspace--; not counted towards exec args total */
5903 }
5904
5905 /*
5906 * From now on, we start attributing string space to ip_argspace
5907 */
5908 imgp->ip_startargv = imgp->ip_strendp;
5909 imgp->ip_argc = 0;
5910
5911 if ((imgp->ip_flags & IMGPF_INTERPRET) != 0) {
5912 user_addr_t arg;
5913 char *argstart, *ch;
5914
5915 /* First, the arguments in the "#!" string are tokenized and extracted. */
5916 argstart = imgp->ip_interp_buffer;
5917 while (argstart) {
5918 ch = argstart;
5919 while (*ch && !IS_WHITESPACE(*ch)) {
5920 ch++;
5921 }
5922
5923 if (*ch == '\0') {
5924 /* last argument, no need to NUL-terminate */
5925 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5926 argstart = NULL;
5927 } else {
5928 /* NUL-terminate */
5929 *ch = '\0';
5930 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(argstart), UIO_SYSSPACE, TRUE);
5931
5932 /*
5933 * Find the next string. We know spaces at the end of the string have already
5934 * been stripped.
5935 */
5936 argstart = ch + 1;
5937 while (IS_WHITESPACE(*argstart)) {
5938 argstart++;
5939 }
5940 }
5941
5942 /* Error-check, regardless of whether this is the last interpreter arg or not */
5943 if (error) {
5944 goto bad;
5945 }
5946 if (imgp->ip_argspace < new_ptr_size) {
5947 error = E2BIG;
5948 goto bad;
5949 }
5950 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5951 imgp->ip_argc++;
5952 }
5953
5954 if (argv != 0LL) {
5955 /*
5956 * If we are running an interpreter, replace the av[0] that was
5957 * passed to execve() with the path name that was
5958 * passed to execve() for interpreters which do not use the PATH
5959 * to locate their script arguments.
5960 */
5961 error = copyinptr(argv, &arg, ptr_size);
5962 if (error) {
5963 goto bad;
5964 }
5965 if (arg != 0LL) {
5966 argv += ptr_size; /* consume without using */
5967 }
5968 }
5969
5970 if (imgp->ip_interp_sugid_fd != -1) {
5971 char temp[19]; /* "/dev/fd/" + 10 digits + NUL */
5972 snprintf(temp, sizeof(temp), "/dev/fd/%d", imgp->ip_interp_sugid_fd);
5973 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(temp), UIO_SYSSPACE, TRUE);
5974 } else {
5975 error = exec_add_user_string(imgp, imgp->ip_user_fname, imgp->ip_seg, TRUE);
5976 }
5977
5978 if (error) {
5979 goto bad;
5980 }
5981 if (imgp->ip_argspace < new_ptr_size) {
5982 error = E2BIG;
5983 goto bad;
5984 }
5985 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
5986 imgp->ip_argc++;
5987 }
5988
5989 while (argv != 0LL) {
5990 user_addr_t arg;
5991
5992 error = copyinptr(argv, &arg, ptr_size);
5993 if (error) {
5994 goto bad;
5995 }
5996
5997 if (arg == 0LL) {
5998 break;
5999 }
6000
6001 argv += ptr_size;
6002
6003 /*
6004 * av[n...] = arg[n]
6005 */
6006 error = exec_add_user_string(imgp, arg, imgp->ip_seg, TRUE);
6007 if (error) {
6008 goto bad;
6009 }
6010 if (imgp->ip_argspace < new_ptr_size) {
6011 error = E2BIG;
6012 goto bad;
6013 }
6014 imgp->ip_argspace -= new_ptr_size; /* to hold argv[] entry */
6015 imgp->ip_argc++;
6016 }
6017
6018 /* Save space for argv[] NULL terminator */
6019 if (imgp->ip_argspace < new_ptr_size) {
6020 error = E2BIG;
6021 goto bad;
6022 }
6023 imgp->ip_argspace -= new_ptr_size;
6024
6025 /* Note where the args ends and env begins. */
6026 imgp->ip_endargv = imgp->ip_strendp;
6027 imgp->ip_envc = 0;
6028
6029 /* Now, get the environment */
6030 while (envv != 0LL) {
6031 user_addr_t env;
6032
6033 error = copyinptr(envv, &env, ptr_size);
6034 if (error) {
6035 goto bad;
6036 }
6037
6038 envv += ptr_size;
6039 if (env == 0LL) {
6040 break;
6041 }
6042 /*
6043 * av[n...] = env[n]
6044 */
6045 error = exec_add_user_string(imgp, env, imgp->ip_seg, TRUE);
6046 if (error) {
6047 goto bad;
6048 }
6049 if (imgp->ip_argspace < new_ptr_size) {
6050 error = E2BIG;
6051 goto bad;
6052 }
6053 imgp->ip_argspace -= new_ptr_size; /* to hold envv[] entry */
6054 imgp->ip_envc++;
6055 }
6056
6057 /* Save space for envv[] NULL terminator */
6058 if (imgp->ip_argspace < new_ptr_size) {
6059 error = E2BIG;
6060 goto bad;
6061 }
6062 imgp->ip_argspace -= new_ptr_size;
6063
6064 /* Align the tail of the combined argv+envv area */
6065 while (imgp->ip_strspace % new_ptr_size != 0) {
6066 if (imgp->ip_argspace < 1) {
6067 error = E2BIG;
6068 goto bad;
6069 }
6070 *imgp->ip_strendp++ = '\0';
6071 imgp->ip_strspace--;
6072 imgp->ip_argspace--;
6073 }
6074
6075 /* Note where the envv ends and applev begins. */
6076 imgp->ip_endenvv = imgp->ip_strendp;
6077
6078 /*
6079 * From now on, we are no longer charging argument
6080 * space to ip_argspace.
6081 */
6082
6083 bad:
6084 return error;
6085 }
6086
6087 /*
6088 * Libc has an 8-element array set up for stack guard values. It only fills
6089 * in one of those entries, and both gcc and llvm seem to use only a single
6090 * 8-byte guard. Until somebody needs more than an 8-byte guard value, don't
6091 * do the work to construct them.
6092 */
6093 #define GUARD_VALUES 1
6094 #define GUARD_KEY "stack_guard="
6095
6096 /*
6097 * System malloc needs some entropy when it is initialized.
6098 */
6099 #define ENTROPY_VALUES 2
6100 #define ENTROPY_KEY "malloc_entropy="
6101
6102 /*
6103 * libplatform needs a random pointer-obfuscation value when it is initialized.
6104 */
6105 #define PTR_MUNGE_VALUES 1
6106 #define PTR_MUNGE_KEY "ptr_munge="
6107
6108 /*
6109 * System malloc engages nanozone for UIAPP.
6110 */
6111 #define NANO_ENGAGE_KEY "MallocNanoZone=1"
6112
6113 /*
6114 * Used to pass experiment flags up to libmalloc.
6115 */
6116 #define LIBMALLOC_EXPERIMENT_FACTORS_KEY "MallocExperiment="
6117
6118 /*
6119 * Passes information about hardened runtime entitlements to libsystem/libmalloc
6120 */
6121 #define HARDENED_RUNTIME_KEY "HardenedRuntime="
6122
6123 #define PFZ_KEY "pfz="
6124 extern user32_addr_t commpage_text32_location;
6125 extern user64_addr_t commpage_text64_location;
6126
6127 extern uuid_string_t bootsessionuuid_string;
6128 static TUNABLE(uint32_t, exe_boothash_salt, "exe_boothash_salt", 0);
6129
6130 __startup_func
6131 static void
exe_boothash_salt_generate(void)6132 exe_boothash_salt_generate(void)
6133 {
6134 if (!PE_parse_boot_argn("exe_boothash_salt", NULL, 0)) {
6135 read_random(&exe_boothash_salt, sizeof(exe_boothash_salt));
6136 }
6137 }
6138 STARTUP(EARLY_BOOT, STARTUP_RANK_MIDDLE, exe_boothash_salt_generate);
6139
6140
6141 #define MAIN_STACK_VALUES 4
6142 #define MAIN_STACK_KEY "main_stack="
6143
6144 #define FSID_KEY "executable_file="
6145 #define DYLD_FSID_KEY "dyld_file="
6146 #define CDHASH_KEY "executable_cdhash="
6147 #define DYLD_FLAGS_KEY "dyld_flags="
6148 #define SUBSYSTEM_ROOT_PATH_KEY "subsystem_root_path="
6149 #define APP_BOOT_SESSION_KEY "executable_boothash="
6150 #if __has_feature(ptrauth_calls)
6151 #define PTRAUTH_DISABLED_FLAG "ptrauth_disabled=1"
6152 #define DYLD_ARM64E_ABI_KEY "arm64e_abi="
6153 #endif /* __has_feature(ptrauth_calls) */
6154 #define MAIN_TH_PORT_KEY "th_port="
6155
6156 #define FSID_MAX_STRING "0x1234567890abcdef,0x1234567890abcdef"
6157
6158 #define HEX_STR_LEN 18 // 64-bit hex value "0x0123456701234567"
6159 #define HEX_STR_LEN32 10 // 32-bit hex value "0x01234567"
6160
6161 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6162 #define VM_FORCE_4K_PAGES_KEY "vm_force_4k_pages=1"
6163 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6164
6165 static int
exec_add_entropy_key(struct image_params * imgp,const char * key,int values,boolean_t embedNUL)6166 exec_add_entropy_key(struct image_params *imgp,
6167 const char *key,
6168 int values,
6169 boolean_t embedNUL)
6170 {
6171 const int limit = 8;
6172 uint64_t entropy[limit];
6173 char str[strlen(key) + (HEX_STR_LEN + 1) * limit + 1];
6174 if (values > limit) {
6175 values = limit;
6176 }
6177
6178 read_random(entropy, sizeof(entropy[0]) * values);
6179
6180 if (embedNUL) {
6181 entropy[0] &= ~(0xffull << 8);
6182 }
6183
6184 int len = scnprintf(str, sizeof(str), "%s0x%llx", key, entropy[0]);
6185 size_t remaining = sizeof(str) - len;
6186 for (int i = 1; i < values && remaining > 0; ++i) {
6187 size_t start = sizeof(str) - remaining;
6188 len = scnprintf(&str[start], remaining, ",0x%llx", entropy[i]);
6189 remaining -= len;
6190 }
6191
6192 return exec_add_user_string(imgp, CAST_USER_ADDR_T(str), UIO_SYSSPACE, FALSE);
6193 }
6194
6195 /*
6196 * Build up the contents of the apple[] string vector
6197 */
6198 #if (DEVELOPMENT || DEBUG)
6199 extern uint64_t dyld_flags;
6200 #endif
6201
6202 #if __has_feature(ptrauth_calls)
6203 static inline bool
is_arm64e_running_as_arm64(const struct image_params * imgp)6204 is_arm64e_running_as_arm64(const struct image_params *imgp)
6205 {
6206 return (imgp->ip_origcpusubtype & ~CPU_SUBTYPE_MASK) == CPU_SUBTYPE_ARM64E &&
6207 (imgp->ip_flags & IMGPF_NOJOP);
6208 }
6209 #endif /* __has_feature(ptrauth_calls) */
6210
6211 _Atomic uint64_t libmalloc_experiment_factors = 0;
6212
6213 static int
exec_add_apple_strings(struct image_params * imgp,const load_result_t * load_result)6214 exec_add_apple_strings(struct image_params *imgp,
6215 const load_result_t *load_result)
6216 {
6217 int error;
6218 int img_ptr_size = (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) ? 8 : 4;
6219 thread_t new_thread;
6220 ipc_port_t sright;
6221 uint64_t local_experiment_factors = 0;
6222
6223 /* exec_save_path stored the first string */
6224 imgp->ip_applec = 1;
6225
6226 /* adding the pfz string */
6227 {
6228 char pfz_string[strlen(PFZ_KEY) + HEX_STR_LEN + 1];
6229
6230 if (img_ptr_size == 8) {
6231 __assert_only size_t ret = snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%llx", commpage_text64_location);
6232 assert(ret < sizeof(pfz_string));
6233 } else {
6234 snprintf(pfz_string, sizeof(pfz_string), PFZ_KEY "0x%x", commpage_text32_location);
6235 }
6236 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(pfz_string), UIO_SYSSPACE, FALSE);
6237 if (error) {
6238 printf("Failed to add the pfz string with error %d\n", error);
6239 goto bad;
6240 }
6241 imgp->ip_applec++;
6242 }
6243
6244 /* adding the NANO_ENGAGE_KEY key */
6245 if (imgp->ip_px_sa) {
6246 struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6247 int proc_flags = psa->psa_flags;
6248
6249 if ((proc_flags & _POSIX_SPAWN_NANO_ALLOCATOR) == _POSIX_SPAWN_NANO_ALLOCATOR) {
6250 const char *nano_string = NANO_ENGAGE_KEY;
6251 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(nano_string), UIO_SYSSPACE, FALSE);
6252 if (error) {
6253 goto bad;
6254 }
6255 imgp->ip_applec++;
6256 }
6257 }
6258
6259 /*
6260 * Supply libc with a collection of random values to use when
6261 * implementing -fstack-protector.
6262 *
6263 * (The first random string always contains an embedded NUL so that
6264 * __stack_chk_guard also protects against C string vulnerabilities)
6265 */
6266 error = exec_add_entropy_key(imgp, GUARD_KEY, GUARD_VALUES, TRUE);
6267 if (error) {
6268 goto bad;
6269 }
6270 imgp->ip_applec++;
6271
6272 /*
6273 * Supply libc with entropy for system malloc.
6274 */
6275 error = exec_add_entropy_key(imgp, ENTROPY_KEY, ENTROPY_VALUES, FALSE);
6276 if (error) {
6277 goto bad;
6278 }
6279 imgp->ip_applec++;
6280
6281 /*
6282 * Supply libpthread & libplatform with a random value to use for pointer
6283 * obfuscation.
6284 */
6285 error = exec_add_entropy_key(imgp, PTR_MUNGE_KEY, PTR_MUNGE_VALUES, FALSE);
6286 if (error) {
6287 goto bad;
6288 }
6289 imgp->ip_applec++;
6290
6291 /*
6292 * Add MAIN_STACK_KEY: Supplies the address and size of the main thread's
6293 * stack if it was allocated by the kernel.
6294 *
6295 * The guard page is not included in this stack size as libpthread
6296 * expects to add it back in after receiving this value.
6297 */
6298 if (load_result->unixproc) {
6299 char stack_string[strlen(MAIN_STACK_KEY) + (HEX_STR_LEN + 1) * MAIN_STACK_VALUES + 1];
6300 snprintf(stack_string, sizeof(stack_string),
6301 MAIN_STACK_KEY "0x%llx,0x%llx,0x%llx,0x%llx",
6302 (uint64_t)load_result->user_stack,
6303 (uint64_t)load_result->user_stack_size,
6304 (uint64_t)load_result->user_stack_alloc,
6305 (uint64_t)load_result->user_stack_alloc_size);
6306 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(stack_string), UIO_SYSSPACE, FALSE);
6307 if (error) {
6308 goto bad;
6309 }
6310 imgp->ip_applec++;
6311 }
6312
6313 if (imgp->ip_vattr) {
6314 uint64_t fsid = vnode_get_va_fsid(imgp->ip_vattr);
6315 uint64_t fsobjid = imgp->ip_vattr->va_fileid;
6316
6317 char fsid_string[strlen(FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6318 snprintf(fsid_string, sizeof(fsid_string),
6319 FSID_KEY "0x%llx,0x%llx", fsid, fsobjid);
6320 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6321 if (error) {
6322 goto bad;
6323 }
6324 imgp->ip_applec++;
6325 }
6326
6327 if (imgp->ip_dyld_fsid || imgp->ip_dyld_fsobjid) {
6328 char fsid_string[strlen(DYLD_FSID_KEY) + strlen(FSID_MAX_STRING) + 1];
6329 snprintf(fsid_string, sizeof(fsid_string),
6330 DYLD_FSID_KEY "0x%llx,0x%llx", imgp->ip_dyld_fsid, imgp->ip_dyld_fsobjid);
6331 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(fsid_string), UIO_SYSSPACE, FALSE);
6332 if (error) {
6333 goto bad;
6334 }
6335 imgp->ip_applec++;
6336 }
6337
6338 uint8_t cdhash[SHA1_RESULTLEN];
6339 int cdhash_errror = ubc_cs_getcdhash(imgp->ip_vp, imgp->ip_arch_offset, cdhash);
6340 if (cdhash_errror == 0) {
6341 char hash_string[strlen(CDHASH_KEY) + 2 * SHA1_RESULTLEN + 1];
6342 strncpy(hash_string, CDHASH_KEY, sizeof(hash_string));
6343 char *p = hash_string + sizeof(CDHASH_KEY) - 1;
6344 for (int i = 0; i < SHA1_RESULTLEN; i++) {
6345 snprintf(p, 3, "%02x", (int) cdhash[i]);
6346 p += 2;
6347 }
6348 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hash_string), UIO_SYSSPACE, FALSE);
6349 if (error) {
6350 goto bad;
6351 }
6352 imgp->ip_applec++;
6353
6354 /* hash together cd-hash and boot-session-uuid */
6355 uint8_t sha_digest[SHA256_DIGEST_LENGTH];
6356 SHA256_CTX sha_ctx;
6357 SHA256_Init(&sha_ctx);
6358 SHA256_Update(&sha_ctx, &exe_boothash_salt, sizeof(exe_boothash_salt));
6359 SHA256_Update(&sha_ctx, bootsessionuuid_string, sizeof(bootsessionuuid_string));
6360 SHA256_Update(&sha_ctx, cdhash, sizeof(cdhash));
6361 SHA256_Final(sha_digest, &sha_ctx);
6362 char app_boot_string[strlen(APP_BOOT_SESSION_KEY) + 2 * SHA1_RESULTLEN + 1];
6363 strncpy(app_boot_string, APP_BOOT_SESSION_KEY, sizeof(app_boot_string));
6364 char *s = app_boot_string + sizeof(APP_BOOT_SESSION_KEY) - 1;
6365 for (int i = 0; i < SHA1_RESULTLEN; i++) {
6366 snprintf(s, 3, "%02x", (int) sha_digest[i]);
6367 s += 2;
6368 }
6369 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(app_boot_string), UIO_SYSSPACE, FALSE);
6370 if (error) {
6371 goto bad;
6372 }
6373 imgp->ip_applec++;
6374 }
6375 #if (DEVELOPMENT || DEBUG)
6376 if (dyld_flags) {
6377 char dyld_flags_string[strlen(DYLD_FLAGS_KEY) + HEX_STR_LEN + 1];
6378 snprintf(dyld_flags_string, sizeof(dyld_flags_string), DYLD_FLAGS_KEY "0x%llx", dyld_flags);
6379 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_flags_string), UIO_SYSSPACE, FALSE);
6380 if (error) {
6381 goto bad;
6382 }
6383 imgp->ip_applec++;
6384 }
6385 #endif
6386 if (imgp->ip_subsystem_root_path) {
6387 size_t buffer_len = MAXPATHLEN + strlen(SUBSYSTEM_ROOT_PATH_KEY);
6388 char subsystem_root_path_string[buffer_len];
6389 int required_len = snprintf(subsystem_root_path_string, buffer_len, SUBSYSTEM_ROOT_PATH_KEY "%s", imgp->ip_subsystem_root_path);
6390
6391 if (((size_t)required_len >= buffer_len) || (required_len < 0)) {
6392 error = ENAMETOOLONG;
6393 goto bad;
6394 }
6395
6396 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(subsystem_root_path_string), UIO_SYSSPACE, FALSE);
6397 if (error) {
6398 goto bad;
6399 }
6400
6401 imgp->ip_applec++;
6402 }
6403 #if __has_feature(ptrauth_calls)
6404 if (is_arm64e_running_as_arm64(imgp)) {
6405 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(PTRAUTH_DISABLED_FLAG), UIO_SYSSPACE, FALSE);
6406 if (error) {
6407 goto bad;
6408 }
6409
6410 imgp->ip_applec++;
6411 }
6412 #endif /* __has_feature(ptrauth_calls) */
6413
6414
6415 #if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
6416 {
6417 char dyld_abi_string[strlen(DYLD_ARM64E_ABI_KEY) + 8];
6418 strlcpy(dyld_abi_string, DYLD_ARM64E_ABI_KEY, sizeof(dyld_abi_string));
6419 bool allowAll = bootarg_arm64e_preview_abi;
6420 strlcat(dyld_abi_string, (allowAll ? "all" : "os"), sizeof(dyld_abi_string));
6421 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_abi_string), UIO_SYSSPACE, FALSE);
6422 if (error) {
6423 goto bad;
6424 }
6425
6426 imgp->ip_applec++;
6427 }
6428 #endif
6429 /*
6430 * Add main thread mach port name
6431 * +1 uref on main thread port, this ref will be extracted by libpthread in __pthread_init
6432 * and consumed in _bsdthread_terminate. Leaking the main thread port name if not linked
6433 * against libpthread.
6434 */
6435 if ((new_thread = imgp->ip_new_thread) != THREAD_NULL) {
6436 thread_reference(new_thread);
6437 sright = convert_thread_to_port_pinned(new_thread);
6438 task_t new_task = get_threadtask(new_thread);
6439 mach_port_name_t name = ipc_port_copyout_send(sright, get_task_ipcspace(new_task));
6440 char port_name_hex_str[strlen(MAIN_TH_PORT_KEY) + HEX_STR_LEN32 + 1];
6441 snprintf(port_name_hex_str, sizeof(port_name_hex_str), MAIN_TH_PORT_KEY "0x%x", name);
6442
6443 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(port_name_hex_str), UIO_SYSSPACE, FALSE);
6444 if (error) {
6445 goto bad;
6446 }
6447 imgp->ip_applec++;
6448 }
6449
6450 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
6451 if (imgp->ip_px_sa != NULL) {
6452 struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
6453 if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
6454 const char *vm_force_4k_string = VM_FORCE_4K_PAGES_KEY;
6455 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(vm_force_4k_string), UIO_SYSSPACE, FALSE);
6456 if (error) {
6457 goto bad;
6458 }
6459 imgp->ip_applec++;
6460 }
6461 }
6462 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES */
6463
6464 /* adding the libmalloc experiment string */
6465 local_experiment_factors = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
6466 if (__improbable(local_experiment_factors != 0)) {
6467 char libmalloc_experiment_factors_string[strlen(LIBMALLOC_EXPERIMENT_FACTORS_KEY) + HEX_STR_LEN + 1];
6468
6469 snprintf(
6470 libmalloc_experiment_factors_string,
6471 sizeof(libmalloc_experiment_factors_string),
6472 LIBMALLOC_EXPERIMENT_FACTORS_KEY "0x%llx",
6473 local_experiment_factors);
6474 error = exec_add_user_string(
6475 imgp,
6476 CAST_USER_ADDR_T(libmalloc_experiment_factors_string),
6477 UIO_SYSSPACE,
6478 FALSE);
6479 if (error) {
6480 printf("Failed to add the libmalloc experiment factors string with error %d\n", error);
6481 goto bad;
6482 }
6483 imgp->ip_applec++;
6484 }
6485
6486
6487 /* tell dyld that it can leverage hardware for its read-only/read-write trusted path */
6488 if (imgp->ip_flags & IMGPF_HW_TPRO) {
6489 const char *dyld_hw_tpro = "dyld_hw_tpro=1";
6490 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(dyld_hw_tpro), UIO_SYSSPACE, FALSE);
6491 if (error) {
6492 printf("Failed to add dyld hw tpro setting with error %d\n", error);
6493 goto bad;
6494 }
6495
6496 imgp->ip_applec++;
6497
6498 }
6499
6500 if (load_result->hardened_runtime_binary) {
6501 const size_t HR_STRING_SIZE = sizeof(HARDENED_RUNTIME_KEY) + HR_FLAGS_NUM_NIBBLES + 2 + 1;
6502 char hardened_runtime[HR_STRING_SIZE];
6503 snprintf(hardened_runtime, HR_STRING_SIZE, HARDENED_RUNTIME_KEY"0x%x", load_result->hardened_runtime_binary);
6504 error = exec_add_user_string(imgp, CAST_USER_ADDR_T(hardened_runtime), UIO_SYSSPACE, FALSE);
6505 if (error) {
6506 printf("Failed to add hardened runtime flag with error %d\n", error);
6507 goto bad;
6508 }
6509 imgp->ip_applec++;
6510 }
6511 /* Align the tail of the combined applev area */
6512 while (imgp->ip_strspace % img_ptr_size != 0) {
6513 *imgp->ip_strendp++ = '\0';
6514 imgp->ip_strspace--;
6515 }
6516
6517 bad:
6518 return error;
6519 }
6520
6521 /*
6522 * exec_check_permissions
6523 *
6524 * Description: Verify that the file that is being attempted to be executed
6525 * is in fact allowed to be executed based on it POSIX file
6526 * permissions and other access control criteria
6527 *
6528 * Parameters: struct image_params * the image parameter block
6529 *
6530 * Returns: 0 Success
6531 * EACCES Permission denied
6532 * ENOEXEC Executable file format error
6533 * ETXTBSY Text file busy [misuse of error code]
6534 * vnode_getattr:???
6535 * vnode_authorize:???
6536 */
6537 static int
exec_check_permissions(struct image_params * imgp)6538 exec_check_permissions(struct image_params *imgp)
6539 {
6540 struct vnode *vp = imgp->ip_vp;
6541 struct vnode_attr *vap = imgp->ip_vattr;
6542 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6543 int error;
6544 kauth_action_t action;
6545
6546 /* Only allow execution of regular files */
6547 if (!vnode_isreg(vp)) {
6548 return EACCES;
6549 }
6550
6551 /* Get the file attributes that we will be using here and elsewhere */
6552 VATTR_INIT(vap);
6553 VATTR_WANTED(vap, va_uid);
6554 VATTR_WANTED(vap, va_gid);
6555 VATTR_WANTED(vap, va_mode);
6556 VATTR_WANTED(vap, va_fsid);
6557 VATTR_WANTED(vap, va_fsid64);
6558 VATTR_WANTED(vap, va_fileid);
6559 VATTR_WANTED(vap, va_data_size);
6560 if ((error = vnode_getattr(vp, vap, imgp->ip_vfs_context)) != 0) {
6561 return error;
6562 }
6563
6564 /*
6565 * Ensure that at least one execute bit is on - otherwise root
6566 * will always succeed, and we don't want to happen unless the
6567 * file really is executable.
6568 */
6569 if (!vfs_authopaque(vnode_mount(vp)) && ((vap->va_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
6570 return EACCES;
6571 }
6572
6573 /* Disallow zero length files */
6574 if (vap->va_data_size == 0) {
6575 return ENOEXEC;
6576 }
6577
6578 imgp->ip_arch_offset = (user_size_t)0;
6579 #if __LP64__
6580 imgp->ip_arch_size = vap->va_data_size;
6581 #else
6582 if (vap->va_data_size > UINT32_MAX) {
6583 return ENOEXEC;
6584 }
6585 imgp->ip_arch_size = (user_size_t)vap->va_data_size;
6586 #endif
6587
6588 /* Disable setuid-ness for traced programs or if MNT_NOSUID */
6589 if ((vp->v_mount->mnt_flag & MNT_NOSUID) || (p->p_lflag & P_LTRACED)) {
6590 vap->va_mode &= ~(VSUID | VSGID);
6591 }
6592
6593 /*
6594 * Disable _POSIX_SPAWN_ALLOW_DATA_EXEC and _POSIX_SPAWN_DISABLE_ASLR
6595 * flags for setuid/setgid binaries.
6596 */
6597 if (vap->va_mode & (VSUID | VSGID)) {
6598 imgp->ip_flags &= ~(IMGPF_ALLOW_DATA_EXEC | IMGPF_DISABLE_ASLR);
6599 }
6600
6601 #if CONFIG_MACF
6602 error = mac_vnode_check_exec(imgp->ip_vfs_context, vp, imgp);
6603 if (error) {
6604 return error;
6605 }
6606 #endif
6607
6608 /* Check for execute permission */
6609 action = KAUTH_VNODE_EXECUTE;
6610 /* Traced images must also be readable */
6611 if (p->p_lflag & P_LTRACED) {
6612 action |= KAUTH_VNODE_READ_DATA;
6613 }
6614 if ((error = vnode_authorize(vp, NULL, action, imgp->ip_vfs_context)) != 0) {
6615 return error;
6616 }
6617
6618 #if 0
6619 /* Don't let it run if anyone had it open for writing */
6620 vnode_lock(vp);
6621 if (vp->v_writecount) {
6622 panic("going to return ETXTBSY %x", vp);
6623 vnode_unlock(vp);
6624 return ETXTBSY;
6625 }
6626 vnode_unlock(vp);
6627 #endif
6628
6629 /* XXX May want to indicate to underlying FS that vnode is open */
6630
6631 return error;
6632 }
6633
6634
6635 /*
6636 * exec_handle_sugid
6637 *
6638 * Initially clear the P_SUGID in the process flags; if an SUGID process is
6639 * exec'ing a non-SUGID image, then this is the point of no return.
6640 *
6641 * If the image being activated is SUGID, then replace the credential with a
6642 * copy, disable tracing (unless the tracing process is root), reset the
6643 * mach task port to revoke it, set the P_SUGID bit,
6644 *
6645 * If the saved user and group ID will be changing, then make sure it happens
6646 * to a new credential, rather than a shared one.
6647 *
6648 * Set the security token (this is probably obsolete, given that the token
6649 * should not technically be separate from the credential itself).
6650 *
6651 * Parameters: struct image_params * the image parameter block
6652 *
6653 * Returns: void No failure indication
6654 *
6655 * Implicit returns:
6656 * <process credential> Potentially modified/replaced
6657 * <task port> Potentially revoked
6658 * <process flags> P_SUGID bit potentially modified
6659 * <security token> Potentially modified
6660 */
6661 __attribute__((noinline))
6662 static int
exec_handle_sugid(struct image_params * imgp)6663 exec_handle_sugid(struct image_params *imgp)
6664 {
6665 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
6666 kauth_cred_t cred = vfs_context_ucred(imgp->ip_vfs_context);
6667 int i;
6668 int leave_sugid_clear = 0;
6669 int mac_reset_ipc = 0;
6670 int error = 0;
6671 #if CONFIG_MACF
6672 int mac_transition, disjoint_cred = 0;
6673 int label_update_return = 0;
6674
6675 /*
6676 * Determine whether a call to update the MAC label will result in the
6677 * credential changing.
6678 *
6679 * Note: MAC policies which do not actually end up modifying
6680 * the label subsequently are strongly encouraged to
6681 * return 0 for this check, since a non-zero answer will
6682 * slow down the exec fast path for normal binaries.
6683 */
6684 mac_transition = mac_cred_check_label_update_execve(
6685 imgp->ip_vfs_context,
6686 imgp->ip_vp,
6687 imgp->ip_arch_offset,
6688 imgp->ip_scriptvp,
6689 imgp->ip_scriptlabelp,
6690 imgp->ip_execlabelp,
6691 p,
6692 &imgp->ip_px_smpx);
6693 #endif
6694
6695 OSBitAndAtomic(~((uint32_t)P_SUGID), &p->p_flag);
6696
6697 /*
6698 * Order of the following is important; group checks must go last,
6699 * as we use the success of the 'ismember' check combined with the
6700 * failure of the explicit match to indicate that we will be setting
6701 * the egid of the process even though the new process did not
6702 * require VSUID/VSGID bits in order for it to set the new group as
6703 * its egid.
6704 *
6705 * Note: Technically, by this we are implying a call to
6706 * setegid() in the new process, rather than implying
6707 * it used its VSGID bit to set the effective group,
6708 * even though there is no code in that process to make
6709 * such a call.
6710 */
6711 if (((imgp->ip_origvattr->va_mode & VSUID) != 0 &&
6712 kauth_cred_getuid(cred) != imgp->ip_origvattr->va_uid) ||
6713 ((imgp->ip_origvattr->va_mode & VSGID) != 0 &&
6714 ((kauth_cred_ismember_gid(cred, imgp->ip_origvattr->va_gid, &leave_sugid_clear) || !leave_sugid_clear) ||
6715 (kauth_cred_getgid(cred) != imgp->ip_origvattr->va_gid)))) {
6716 #if CONFIG_MACF
6717 /* label for MAC transition and neither VSUID nor VSGID */
6718 handle_mac_transition:
6719 #endif
6720
6721 #if CONFIG_SETUID
6722 /*
6723 * Replace the credential with a copy of itself if euid or
6724 * egid change.
6725 *
6726 * Note: setuid binaries will automatically opt out of
6727 * group resolver participation as a side effect
6728 * of this operation. This is an intentional
6729 * part of the security model, which requires a
6730 * participating credential be established by
6731 * escalating privilege, setting up all other
6732 * aspects of the credential including whether
6733 * or not to participate in external group
6734 * membership resolution, then dropping their
6735 * effective privilege to that of the desired
6736 * final credential state.
6737 *
6738 * Modifications to p_ucred must be guarded using the
6739 * proc's ucred lock. This prevents others from accessing
6740 * a garbage credential.
6741 */
6742
6743 if (imgp->ip_origvattr->va_mode & VSUID) {
6744 kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6745 ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6746 return kauth_cred_model_setresuid(model,
6747 KAUTH_UID_NONE,
6748 imgp->ip_origvattr->va_uid,
6749 imgp->ip_origvattr->va_uid,
6750 KAUTH_UID_NONE);
6751 });
6752 }
6753
6754 if (imgp->ip_origvattr->va_mode & VSGID) {
6755 kauth_cred_proc_update(p, PROC_SETTOKEN_NONE,
6756 ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6757 return kauth_cred_model_setresgid(model,
6758 KAUTH_GID_NONE,
6759 imgp->ip_origvattr->va_gid,
6760 imgp->ip_origvattr->va_gid);
6761 });
6762 }
6763 #endif /* CONFIG_SETUID */
6764
6765 #if CONFIG_MACF
6766 /*
6767 * If a policy has indicated that it will transition the label,
6768 * before making the call into the MAC policies, get a new
6769 * duplicate credential, so they can modify it without
6770 * modifying any others sharing it.
6771 */
6772 if (mac_transition) {
6773 /*
6774 * This hook may generate upcalls that require
6775 * importance donation from the kernel.
6776 * (23925818)
6777 */
6778 thread_t thread = current_thread();
6779 thread_enable_send_importance(thread, TRUE);
6780 kauth_proc_label_update_execve(p,
6781 imgp->ip_vfs_context,
6782 imgp->ip_vp,
6783 imgp->ip_arch_offset,
6784 imgp->ip_scriptvp,
6785 imgp->ip_scriptlabelp,
6786 imgp->ip_execlabelp,
6787 &imgp->ip_csflags,
6788 &imgp->ip_px_smpx,
6789 &disjoint_cred, /* will be non zero if disjoint */
6790 &label_update_return);
6791 thread_enable_send_importance(thread, FALSE);
6792
6793 if (disjoint_cred) {
6794 /*
6795 * If updating the MAC label resulted in a
6796 * disjoint credential, flag that we need to
6797 * set the P_SUGID bit. This protects
6798 * against debuggers being attached by an
6799 * insufficiently privileged process onto the
6800 * result of a transition to a more privileged
6801 * credential.
6802 */
6803 leave_sugid_clear = 0;
6804 }
6805
6806 imgp->ip_mac_return = label_update_return;
6807 }
6808
6809 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);
6810
6811 #endif /* CONFIG_MACF */
6812
6813 /*
6814 * If 'leave_sugid_clear' is non-zero, then we passed the
6815 * VSUID and MACF checks, and successfully determined that
6816 * the previous cred was a member of the VSGID group, but
6817 * that it was not the default at the time of the execve,
6818 * and that the post-labelling credential was not disjoint.
6819 * So we don't set the P_SUGID or reset mach ports and fds
6820 * on the basis of simply running this code.
6821 */
6822 if (mac_reset_ipc || !leave_sugid_clear) {
6823 /*
6824 * Have mach reset the task and thread ports.
6825 * We don't want anyone who had the ports before
6826 * a setuid exec to be able to access/control the
6827 * task/thread after.
6828 */
6829 ipc_task_reset((imgp->ip_new_thread != NULL) ?
6830 get_threadtask(imgp->ip_new_thread) : proc_task(p));
6831 ipc_thread_reset((imgp->ip_new_thread != NULL) ?
6832 imgp->ip_new_thread : current_thread());
6833 }
6834
6835 if (!leave_sugid_clear) {
6836 /*
6837 * Flag the process as setuid.
6838 */
6839 OSBitOrAtomic(P_SUGID, &p->p_flag);
6840
6841 /*
6842 * Radar 2261856; setuid security hole fix
6843 * XXX For setuid processes, attempt to ensure that
6844 * stdin, stdout, and stderr are already allocated.
6845 * We do not want userland to accidentally allocate
6846 * descriptors in this range which has implied meaning
6847 * to libc.
6848 */
6849 for (i = 0; i < 3; i++) {
6850 if (fp_get_noref_locked(p, i) != NULL) {
6851 continue;
6852 }
6853
6854 /*
6855 * Do the kernel equivalent of
6856 *
6857 * if i == 0
6858 * (void) open("/dev/null", O_RDONLY);
6859 * else
6860 * (void) open("/dev/null", O_WRONLY);
6861 */
6862
6863 struct fileproc *fp;
6864 int indx;
6865 int flag;
6866 struct nameidata *ndp = NULL;
6867
6868 if (i == 0) {
6869 flag = FREAD;
6870 } else {
6871 flag = FWRITE;
6872 }
6873
6874 if ((error = falloc_exec(p, imgp->ip_vfs_context,
6875 &fp, &indx)) != 0) {
6876 continue;
6877 }
6878
6879 ndp = kalloc_type(struct nameidata,
6880 Z_WAITOK | Z_ZERO | Z_NOFAIL);
6881
6882 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW, UIO_SYSSPACE,
6883 CAST_USER_ADDR_T("/dev/null"),
6884 imgp->ip_vfs_context);
6885
6886 if ((error = vn_open(ndp, flag, 0)) != 0) {
6887 fp_free(p, indx, fp);
6888 kfree_type(struct nameidata, ndp);
6889 break;
6890 }
6891
6892 struct fileglob *fg = fp->fp_glob;
6893
6894 fg->fg_flag = flag;
6895 fg->fg_ops = &vnops;
6896 fp_set_data(fp, ndp->ni_vp);
6897
6898 vnode_put(ndp->ni_vp);
6899
6900 proc_fdlock(p);
6901 procfdtbl_releasefd(p, indx, NULL);
6902 fp_drop(p, indx, fp, 1);
6903 proc_fdunlock(p);
6904
6905 kfree_type(struct nameidata, ndp);
6906 }
6907 }
6908 }
6909 #if CONFIG_MACF
6910 else {
6911 /*
6912 * We are here because we were told that the MAC label will
6913 * be transitioned, and the binary is not VSUID or VSGID; to
6914 * deal with this case, we could either duplicate a lot of
6915 * code, or we can indicate we want to default the P_SUGID
6916 * bit clear and jump back up.
6917 */
6918 if (mac_transition) {
6919 leave_sugid_clear = 1;
6920 goto handle_mac_transition;
6921 }
6922 }
6923
6924 #endif /* CONFIG_MACF */
6925
6926 /* Update the process' identity version and set the security token */
6927 proc_setpidversion(p, OSIncrementAtomic(&nextpidversion));
6928 task_set_uniqueid(proc_task(p));
6929
6930 /*
6931 * Implement the semantic where the effective user and group become
6932 * the saved user and group in exec'ed programs.
6933 */
6934 kauth_cred_proc_update(p, PROC_SETTOKEN_ALWAYS,
6935 ^bool (kauth_cred_t parent __unused, kauth_cred_t model) {
6936 posix_cred_t pcred = posix_cred_get(model);
6937
6938 if (pcred->cr_svuid == pcred->cr_uid &&
6939 pcred->cr_svgid == pcred->cr_gid) {
6940 return false;
6941 }
6942
6943 pcred->cr_svuid = pcred->cr_uid;
6944 pcred->cr_svgid = pcred->cr_gid;
6945 return true;
6946 });
6947
6948 return error;
6949 }
6950
6951
6952 /*
6953 * create_unix_stack
6954 *
6955 * Description: Set the user stack address for the process to the provided
6956 * address. If a custom stack was not set as a result of the
6957 * load process (i.e. as specified by the image file for the
6958 * executable), then allocate the stack in the provided map and
6959 * set up appropriate guard pages for enforcing administrative
6960 * limits on stack growth, if they end up being needed.
6961 *
6962 * Parameters: p Process to set stack on
6963 * load_result Information from mach-o load commands
6964 * map Address map in which to allocate the new stack
6965 *
6966 * Returns: KERN_SUCCESS Stack successfully created
6967 * !KERN_SUCCESS Mach failure code
6968 */
6969 __attribute__((noinline))
6970 static kern_return_t
create_unix_stack(vm_map_t map,load_result_t * load_result,proc_t p)6971 create_unix_stack(vm_map_t map, load_result_t* load_result,
6972 proc_t p)
6973 {
6974 mach_vm_size_t size, prot_size;
6975 mach_vm_offset_t addr, prot_addr;
6976 kern_return_t kr;
6977
6978 mach_vm_address_t user_stack = load_result->user_stack;
6979
6980 proc_lock(p);
6981 p->user_stack = (uintptr_t)user_stack;
6982 if (load_result->custom_stack) {
6983 p->p_lflag |= P_LCUSTOM_STACK;
6984 }
6985 proc_unlock(p);
6986 if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
6987 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);
6988 }
6989
6990 if (load_result->user_stack_alloc_size > 0) {
6991 /*
6992 * Allocate enough space for the maximum stack size we
6993 * will ever authorize and an extra page to act as
6994 * a guard page for stack overflows. For default stacks,
6995 * vm_initial_limit_stack takes care of the extra guard page.
6996 * Otherwise we must allocate it ourselves.
6997 */
6998 if (mach_vm_round_page_overflow(load_result->user_stack_alloc_size, &size)) {
6999 return KERN_INVALID_ARGUMENT;
7000 }
7001 addr = vm_map_trunc_page(load_result->user_stack - size,
7002 vm_map_page_mask(map));
7003 kr = mach_vm_allocate_kernel(map, &addr, size,
7004 VM_MAP_KERNEL_FLAGS_FIXED(.vm_tag = VM_MEMORY_STACK));
7005 if (kr != KERN_SUCCESS) {
7006 // Can't allocate at default location, try anywhere
7007 addr = 0;
7008 kr = mach_vm_allocate_kernel(map, &addr, size,
7009 VM_MAP_KERNEL_FLAGS_ANYWHERE(.vm_tag = VM_MEMORY_STACK));
7010 if (kr != KERN_SUCCESS) {
7011 return kr;
7012 }
7013
7014 user_stack = addr + size;
7015 load_result->user_stack = (user_addr_t)user_stack;
7016
7017 proc_lock(p);
7018 p->user_stack = (uintptr_t)user_stack;
7019 proc_unlock(p);
7020 }
7021
7022 load_result->user_stack_alloc = (user_addr_t)addr;
7023
7024 /*
7025 * And prevent access to what's above the current stack
7026 * size limit for this process.
7027 */
7028 if (load_result->user_stack_size == 0) {
7029 load_result->user_stack_size = proc_limitgetcur(p, RLIMIT_STACK);
7030 prot_size = vm_map_trunc_page(size - load_result->user_stack_size, vm_map_page_mask(map));
7031 } else {
7032 prot_size = PAGE_SIZE;
7033 }
7034
7035 prot_addr = addr;
7036 kr = mach_vm_protect(map,
7037 prot_addr,
7038 prot_size,
7039 FALSE,
7040 VM_PROT_NONE);
7041 if (kr != KERN_SUCCESS) {
7042 (void)mach_vm_deallocate(map, addr, size);
7043 return kr;
7044 }
7045 }
7046
7047 return KERN_SUCCESS;
7048 }
7049
7050 #include <sys/reboot.h>
7051
7052 /*
7053 * load_init_program_at_path
7054 *
7055 * Description: Load the "init" program; in most cases, this will be "launchd"
7056 *
7057 * Parameters: p Process to call execve() to create
7058 * the "init" program
7059 * scratch_addr Page in p, scratch space
7060 * path NULL terminated path
7061 *
7062 * Returns: KERN_SUCCESS Success
7063 * !KERN_SUCCESS See execve/mac_execve for error codes
7064 *
7065 * Notes: The process that is passed in is the first manufactured
7066 * process on the system, and gets here via bsd_ast() firing
7067 * for the first time. This is done to ensure that bsd_init()
7068 * has run to completion.
7069 *
7070 * The address map of the first manufactured process matches the
7071 * word width of the kernel. Once the self-exec completes, the
7072 * initproc might be different.
7073 */
7074 static int
load_init_program_at_path(proc_t p,user_addr_t scratch_addr,const char * path)7075 load_init_program_at_path(proc_t p, user_addr_t scratch_addr, const char* path)
7076 {
7077 int retval[2];
7078 int error;
7079 struct execve_args init_exec_args;
7080 user_addr_t argv0 = USER_ADDR_NULL, argv1 = USER_ADDR_NULL;
7081
7082 /*
7083 * Validate inputs and pre-conditions
7084 */
7085 assert(p);
7086 assert(scratch_addr);
7087 assert(path);
7088
7089 /*
7090 * Copy out program name.
7091 */
7092 size_t path_length = strlen(path) + 1;
7093 argv0 = scratch_addr;
7094 error = copyout(path, argv0, path_length);
7095 if (error) {
7096 return error;
7097 }
7098
7099 scratch_addr = USER_ADDR_ALIGN(scratch_addr + path_length, sizeof(user_addr_t));
7100
7101 /*
7102 * Put out first (and only) argument, similarly.
7103 * Assumes everything fits in a page as allocated above.
7104 */
7105 if (boothowto & RB_SINGLE) {
7106 const char *init_args = "-s";
7107 size_t init_args_length = strlen(init_args) + 1;
7108
7109 argv1 = scratch_addr;
7110 error = copyout(init_args, argv1, init_args_length);
7111 if (error) {
7112 return error;
7113 }
7114
7115 scratch_addr = USER_ADDR_ALIGN(scratch_addr + init_args_length, sizeof(user_addr_t));
7116 }
7117
7118 if (proc_is64bit(p)) {
7119 user64_addr_t argv64bit[3] = {};
7120
7121 argv64bit[0] = argv0;
7122 argv64bit[1] = argv1;
7123 argv64bit[2] = USER_ADDR_NULL;
7124
7125 error = copyout(argv64bit, scratch_addr, sizeof(argv64bit));
7126 if (error) {
7127 return error;
7128 }
7129 } else {
7130 user32_addr_t argv32bit[3] = {};
7131
7132 argv32bit[0] = (user32_addr_t)argv0;
7133 argv32bit[1] = (user32_addr_t)argv1;
7134 argv32bit[2] = USER_ADDR_NULL;
7135
7136 error = copyout(argv32bit, scratch_addr, sizeof(argv32bit));
7137 if (error) {
7138 return error;
7139 }
7140 }
7141
7142 /*
7143 * Set up argument block for fake call to execve.
7144 */
7145 init_exec_args.fname = argv0;
7146 init_exec_args.argp = scratch_addr;
7147 init_exec_args.envp = USER_ADDR_NULL;
7148
7149 /*
7150 * So that init task is set with uid,gid 0 token
7151 *
7152 * The access to the cred is safe:
7153 * the proc isn't running yet, it's stable.
7154 */
7155 set_security_token(p, proc_ucred_unsafe(p));
7156
7157 return execve(p, &init_exec_args, retval);
7158 }
7159
7160 static const char * init_programs[] = {
7161 #if DEBUG
7162 "/usr/appleinternal/sbin/launchd.debug",
7163 #endif
7164 #if DEVELOPMENT || DEBUG
7165 "/usr/appleinternal/sbin/launchd.development",
7166 #endif
7167 "/sbin/launchd",
7168 };
7169
7170 /*
7171 * load_init_program
7172 *
7173 * Description: Load the "init" program; in most cases, this will be "launchd"
7174 *
7175 * Parameters: p Process to call execve() to create
7176 * the "init" program
7177 *
7178 * Returns: (void)
7179 *
7180 * Notes: The process that is passed in is the first manufactured
7181 * process on the system, and gets here via bsd_ast() firing
7182 * for the first time. This is done to ensure that bsd_init()
7183 * has run to completion.
7184 *
7185 * In DEBUG & DEVELOPMENT builds, the launchdsuffix boot-arg
7186 * may be used to select a specific launchd executable. As with
7187 * the kcsuffix boot-arg, setting launchdsuffix to "" or "release"
7188 * will force /sbin/launchd to be selected.
7189 *
7190 * Search order by build:
7191 *
7192 * DEBUG DEVELOPMENT RELEASE PATH
7193 * ----------------------------------------------------------------------------------
7194 * 1 1 NA /usr/appleinternal/sbin/launchd.$LAUNCHDSUFFIX
7195 * 2 NA NA /usr/appleinternal/sbin/launchd.debug
7196 * 3 2 NA /usr/appleinternal/sbin/launchd.development
7197 * 4 3 1 /sbin/launchd
7198 */
7199 void
load_init_program(proc_t p)7200 load_init_program(proc_t p)
7201 {
7202 uint32_t i;
7203 int error;
7204 vm_map_t map = current_map();
7205 mach_vm_offset_t scratch_addr = 0;
7206 mach_vm_size_t map_page_size = vm_map_page_size(map);
7207
7208 (void) mach_vm_allocate_kernel(map, &scratch_addr, map_page_size,
7209 VM_MAP_KERNEL_FLAGS_ANYWHERE());
7210 #if CONFIG_MEMORYSTATUS
7211 (void) memorystatus_init_at_boot_snapshot();
7212 #endif /* CONFIG_MEMORYSTATUS */
7213
7214 #if DEBUG || DEVELOPMENT
7215 /* Check for boot-arg suffix first */
7216 char launchd_suffix[64];
7217 if (PE_parse_boot_argn("launchdsuffix", launchd_suffix, sizeof(launchd_suffix))) {
7218 char launchd_path[128];
7219 boolean_t is_release_suffix = ((launchd_suffix[0] == 0) ||
7220 (strcmp(launchd_suffix, "release") == 0));
7221
7222 if (is_release_suffix) {
7223 printf("load_init_program: attempting to load /sbin/launchd\n");
7224 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, "/sbin/launchd");
7225 if (!error) {
7226 return;
7227 }
7228
7229 panic("Process 1 exec of launchd.release failed, errno %d", error);
7230 } else {
7231 strlcpy(launchd_path, "/usr/appleinternal/sbin/launchd.", sizeof(launchd_path));
7232 strlcat(launchd_path, launchd_suffix, sizeof(launchd_path));
7233
7234 printf("load_init_program: attempting to load %s\n", launchd_path);
7235 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, launchd_path);
7236 if (!error) {
7237 return;
7238 } else if (error != ENOENT) {
7239 printf("load_init_program: failed loading %s: errno %d\n", launchd_path, error);
7240 }
7241 }
7242 }
7243 #endif
7244
7245 error = ENOENT;
7246 for (i = 0; i < sizeof(init_programs) / sizeof(init_programs[0]); i++) {
7247 printf("load_init_program: attempting to load %s\n", init_programs[i]);
7248 error = load_init_program_at_path(p, (user_addr_t)scratch_addr, init_programs[i]);
7249 if (!error) {
7250 return;
7251 } else if (error != ENOENT) {
7252 printf("load_init_program: failed loading %s: errno %d\n", init_programs[i], error);
7253 }
7254 }
7255
7256 panic("Process 1 exec of %s failed, errno %d", ((i == 0) ? "<null>" : init_programs[i - 1]), error);
7257 }
7258
7259 /*
7260 * load_return_to_errno
7261 *
7262 * Description: Convert a load_return_t (Mach error) to an errno (BSD error)
7263 *
7264 * Parameters: lrtn Mach error number
7265 *
7266 * Returns: (int) BSD error number
7267 * 0 Success
7268 * EBADARCH Bad architecture
7269 * EBADMACHO Bad Mach object file
7270 * ESHLIBVERS Bad shared library version
7271 * ENOMEM Out of memory/resource shortage
7272 * EACCES Access denied
7273 * ENOENT Entry not found (usually "file does
7274 * does not exist")
7275 * EIO An I/O error occurred
7276 * EBADEXEC The executable is corrupt/unknown
7277 */
7278 static int
load_return_to_errno(load_return_t lrtn)7279 load_return_to_errno(load_return_t lrtn)
7280 {
7281 switch (lrtn) {
7282 case LOAD_SUCCESS:
7283 return 0;
7284 case LOAD_BADARCH:
7285 return EBADARCH;
7286 case LOAD_BADMACHO:
7287 case LOAD_BADMACHO_UPX:
7288 return EBADMACHO;
7289 case LOAD_SHLIB:
7290 return ESHLIBVERS;
7291 case LOAD_NOSPACE:
7292 case LOAD_RESOURCE:
7293 return ENOMEM;
7294 case LOAD_PROTECT:
7295 return EACCES;
7296 case LOAD_ENOENT:
7297 return ENOENT;
7298 case LOAD_IOERROR:
7299 return EIO;
7300 case LOAD_DECRYPTFAIL:
7301 return EAUTH;
7302 case LOAD_FAILURE:
7303 default:
7304 return EBADEXEC;
7305 }
7306 }
7307
7308 #include <mach/mach_types.h>
7309 #include <mach/vm_prot.h>
7310 #include <mach/semaphore.h>
7311 #include <mach/sync_policy.h>
7312 #include <kern/clock.h>
7313 #include <mach/kern_return.h>
7314
7315 /*
7316 * execargs_alloc
7317 *
7318 * Description: Allocate the block of memory used by the execve arguments.
7319 * At the same time, we allocate a page so that we can read in
7320 * the first page of the image.
7321 *
7322 * Parameters: struct image_params * the image parameter block
7323 *
7324 * Returns: 0 Success
7325 * EINVAL Invalid argument
7326 * EACCES Permission denied
7327 * EINTR Interrupted function
7328 * ENOMEM Not enough space
7329 *
7330 * Notes: This is a temporary allocation into the kernel address space
7331 * to enable us to copy arguments in from user space. This is
7332 * necessitated by not mapping the process calling execve() into
7333 * the kernel address space during the execve() system call.
7334 *
7335 * We assemble the argument and environment, etc., into this
7336 * region before copying it as a single block into the child
7337 * process address space (at the top or bottom of the stack,
7338 * depending on which way the stack grows; see the function
7339 * exec_copyout_strings() for details).
7340 *
7341 * This ends up with a second (possibly unnecessary) copy compared
7342 * with assembing the data directly into the child address space,
7343 * instead, but since we cannot be guaranteed that the parent has
7344 * not modified its environment, we can't really know that it's
7345 * really a block there as well.
7346 */
7347
7348
7349 static int execargs_waiters = 0;
7350 static LCK_MTX_DECLARE_ATTR(execargs_cache_lock, &proc_lck_grp, &proc_lck_attr);
7351
7352 static void
execargs_lock_lock(void)7353 execargs_lock_lock(void)
7354 {
7355 lck_mtx_lock_spin(&execargs_cache_lock);
7356 }
7357
7358 static void
execargs_lock_unlock(void)7359 execargs_lock_unlock(void)
7360 {
7361 lck_mtx_unlock(&execargs_cache_lock);
7362 }
7363
7364 static wait_result_t
execargs_lock_sleep(void)7365 execargs_lock_sleep(void)
7366 {
7367 return lck_mtx_sleep(&execargs_cache_lock, LCK_SLEEP_DEFAULT, &execargs_free_count, THREAD_INTERRUPTIBLE);
7368 }
7369
7370 static kern_return_t
execargs_purgeable_allocate(char ** execarg_address)7371 execargs_purgeable_allocate(char **execarg_address)
7372 {
7373 mach_vm_offset_t addr = 0;
7374 kern_return_t kr = mach_vm_allocate_kernel(bsd_pageable_map, &addr,
7375 BSD_PAGEABLE_SIZE_PER_EXEC,
7376 VM_MAP_KERNEL_FLAGS_ANYWHERE(.vmf_purgeable = true));
7377 *execarg_address = (char *)addr;
7378 assert(kr == KERN_SUCCESS);
7379 return kr;
7380 }
7381
7382 static kern_return_t
execargs_purgeable_reference(void * execarg_address)7383 execargs_purgeable_reference(void *execarg_address)
7384 {
7385 int state = VM_PURGABLE_NONVOLATILE;
7386 kern_return_t kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7387
7388 assert(kr == KERN_SUCCESS);
7389 return kr;
7390 }
7391
7392 static kern_return_t
execargs_purgeable_volatilize(void * execarg_address)7393 execargs_purgeable_volatilize(void *execarg_address)
7394 {
7395 int state = VM_PURGABLE_VOLATILE | VM_PURGABLE_ORDERING_OBSOLETE;
7396 kern_return_t kr;
7397 kr = vm_purgable_control(bsd_pageable_map, (vm_offset_t) execarg_address, VM_PURGABLE_SET_STATE, &state);
7398
7399 assert(kr == KERN_SUCCESS);
7400
7401 return kr;
7402 }
7403
7404 static void
execargs_wakeup_waiters(void)7405 execargs_wakeup_waiters(void)
7406 {
7407 thread_wakeup(&execargs_free_count);
7408 }
7409
7410 static int
execargs_alloc(struct image_params * imgp)7411 execargs_alloc(struct image_params *imgp)
7412 {
7413 kern_return_t kret;
7414 wait_result_t res;
7415 int i, cache_index = -1;
7416
7417 execargs_lock_lock();
7418
7419 while (execargs_free_count == 0) {
7420 execargs_waiters++;
7421 res = execargs_lock_sleep();
7422 execargs_waiters--;
7423 if (res != THREAD_AWAKENED) {
7424 execargs_lock_unlock();
7425 return EINTR;
7426 }
7427 }
7428
7429 execargs_free_count--;
7430
7431 for (i = 0; i < execargs_cache_size; i++) {
7432 vm_offset_t element = execargs_cache[i];
7433 if (element) {
7434 cache_index = i;
7435 imgp->ip_strings = (char *)(execargs_cache[i]);
7436 execargs_cache[i] = 0;
7437 break;
7438 }
7439 }
7440
7441 assert(execargs_free_count >= 0);
7442
7443 execargs_lock_unlock();
7444
7445 if (cache_index == -1) {
7446 kret = execargs_purgeable_allocate(&imgp->ip_strings);
7447 } else {
7448 kret = execargs_purgeable_reference(imgp->ip_strings);
7449 }
7450
7451 assert(kret == KERN_SUCCESS);
7452 if (kret != KERN_SUCCESS) {
7453 return ENOMEM;
7454 }
7455
7456 /* last page used to read in file headers */
7457 imgp->ip_vdata = imgp->ip_strings + (NCARGS + PAGE_SIZE);
7458 imgp->ip_strendp = imgp->ip_strings;
7459 imgp->ip_argspace = NCARGS;
7460 imgp->ip_strspace = (NCARGS + PAGE_SIZE);
7461
7462 return 0;
7463 }
7464
7465 /*
7466 * execargs_free
7467 *
7468 * Description: Free the block of memory used by the execve arguments and the
7469 * first page of the executable by a previous call to the function
7470 * execargs_alloc().
7471 *
7472 * Parameters: struct image_params * the image parameter block
7473 *
7474 * Returns: 0 Success
7475 * EINVAL Invalid argument
7476 * EINTR Oeration interrupted
7477 */
7478 static int
execargs_free(struct image_params * imgp)7479 execargs_free(struct image_params *imgp)
7480 {
7481 kern_return_t kret;
7482 int i;
7483 boolean_t needs_wakeup = FALSE;
7484
7485 kret = execargs_purgeable_volatilize(imgp->ip_strings);
7486
7487 execargs_lock_lock();
7488 execargs_free_count++;
7489
7490 for (i = 0; i < execargs_cache_size; i++) {
7491 vm_offset_t element = execargs_cache[i];
7492 if (element == 0) {
7493 execargs_cache[i] = (vm_offset_t) imgp->ip_strings;
7494 imgp->ip_strings = NULL;
7495 break;
7496 }
7497 }
7498
7499 assert(imgp->ip_strings == NULL);
7500
7501 if (execargs_waiters > 0) {
7502 needs_wakeup = TRUE;
7503 }
7504
7505 execargs_lock_unlock();
7506
7507 if (needs_wakeup == TRUE) {
7508 execargs_wakeup_waiters();
7509 }
7510
7511 return kret == KERN_SUCCESS ? 0 : EINVAL;
7512 }
7513
7514 void
uthread_set_exec_data(struct uthread * uth,struct image_params * imgp)7515 uthread_set_exec_data(struct uthread *uth, struct image_params *imgp)
7516 {
7517 uth->uu_save.uus_exec_data.imgp = imgp;
7518 }
7519
7520 size_t
thread_get_current_exec_path(char * path,size_t size)7521 thread_get_current_exec_path(char *path, size_t size)
7522 {
7523 struct uthread *uth = current_uthread();
7524 struct image_params *imgp = uth->uu_save.uus_exec_data.imgp;
7525 size_t string_size = 0;
7526 char *exec_path;
7527
7528 if (path == NULL || imgp == NULL || imgp->ip_strings == NULL) {
7529 return 0;
7530 }
7531
7532 exec_path = imgp->ip_strings + strlen(EXECUTABLE_KEY);
7533 string_size = imgp->ip_strendp - exec_path;
7534 string_size = MIN(MAXPATHLEN, string_size);
7535 string_size = MIN(size, string_size);
7536
7537 string_size = strlcpy(path, exec_path, string_size);
7538 return string_size;
7539 }
7540 static void
exec_resettextvp(proc_t p,struct image_params * imgp)7541 exec_resettextvp(proc_t p, struct image_params *imgp)
7542 {
7543 vnode_t vp;
7544 off_t offset;
7545 vnode_t tvp = p->p_textvp;
7546 int ret;
7547
7548 vp = imgp->ip_vp;
7549 offset = imgp->ip_arch_offset;
7550
7551 if (vp == NULLVP) {
7552 panic("exec_resettextvp: expected valid vp");
7553 }
7554
7555 ret = vnode_ref(vp);
7556 proc_lock(p);
7557 if (ret == 0) {
7558 p->p_textvp = vp;
7559 p->p_textoff = offset;
7560 } else {
7561 p->p_textvp = NULLVP; /* this is paranoia */
7562 p->p_textoff = 0;
7563 }
7564 proc_unlock(p);
7565
7566 if (tvp != NULLVP) {
7567 if (vnode_getwithref(tvp) == 0) {
7568 vnode_rele(tvp);
7569 vnode_put(tvp);
7570 }
7571 }
7572 }
7573
7574 // Includes the 0-byte (therefore "SIZE" instead of "LEN").
7575 static const size_t CS_CDHASH_STRING_SIZE = CS_CDHASH_LEN * 2 + 1;
7576
7577 static void
cdhash_to_string(char str[CS_CDHASH_STRING_SIZE],uint8_t const * const cdhash)7578 cdhash_to_string(char str[CS_CDHASH_STRING_SIZE], uint8_t const * const cdhash)
7579 {
7580 static char const nibble[] = "0123456789abcdef";
7581
7582 /* Apparently still the safest way to get a hex representation
7583 * of binary data.
7584 * xnu's printf routines have %*D/%20D in theory, but "not really", see:
7585 * <rdar://problem/33328859> confusion around %*D/%nD in printf
7586 */
7587 for (int i = 0; i < CS_CDHASH_LEN; ++i) {
7588 str[i * 2] = nibble[(cdhash[i] & 0xf0) >> 4];
7589 str[i * 2 + 1] = nibble[cdhash[i] & 0x0f];
7590 }
7591 str[CS_CDHASH_STRING_SIZE - 1] = 0;
7592 }
7593
7594 /*
7595 * __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__
7596 *
7597 * Description: Waits for the userspace daemon to respond to the request
7598 * we made. Function declared non inline to be visible in
7599 * stackshots and spindumps as well as debugging.
7600 */
7601 __attribute__((noinline)) int
__EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port,int32_t new_pid)7602 __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(mach_port_t task_access_port, int32_t new_pid)
7603 {
7604 return find_code_signature(task_access_port, new_pid);
7605 }
7606
7607 /*
7608 * Update signature dependent process state, called by
7609 * process_signature.
7610 */
7611 static int
proc_process_signature(proc_t p,os_reason_t * signature_failure_reason)7612 proc_process_signature(proc_t p, os_reason_t *signature_failure_reason)
7613 {
7614 int error = 0;
7615 char const *error_msg = NULL;
7616
7617 kern_return_t kr = machine_task_process_signature(proc_get_task_raw(p), proc_platform(p), proc_sdk(p), &error_msg);
7618
7619 if (kr != KERN_SUCCESS) {
7620 error = EINVAL;
7621
7622 if (error_msg != NULL) {
7623 uint32_t error_msg_len = (uint32_t)strlen(error_msg) + 1;
7624 mach_vm_address_t data_addr = 0;
7625 int reason_error = 0;
7626 int kcdata_error = 0;
7627
7628 os_reason_t reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7629 reason->osr_flags = OS_REASON_FLAG_GENERATE_CRASH_REPORT | OS_REASON_FLAG_CONSISTENT_FAILURE;
7630
7631 if ((reason_error = os_reason_alloc_buffer_noblock(reason,
7632 kcdata_estimate_required_buffer_size(1, error_msg_len))) == 0 &&
7633 (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
7634 EXIT_REASON_USER_DESC, error_msg_len,
7635 &data_addr)) == KERN_SUCCESS) {
7636 kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
7637 error_msg, error_msg_len);
7638
7639 if (mc_error != KERN_SUCCESS) {
7640 printf("process_signature: failed to copy reason string (kcdata_memcpy error: %d)\n",
7641 mc_error);
7642 }
7643 } else {
7644 printf("failed to allocate space for reason string (os_reason_alloc_buffer error: %d, kcdata error: %d, length: %u)\n",
7645 reason_error, kcdata_error, error_msg_len);
7646 }
7647
7648 assert(*signature_failure_reason == NULL); // shouldn't have gotten so far
7649 *signature_failure_reason = reason;
7650 }
7651 }
7652 return error;
7653 }
7654
7655 static int
process_signature(proc_t p,struct image_params * imgp)7656 process_signature(proc_t p, struct image_params *imgp)
7657 {
7658 mach_port_t port = IPC_PORT_NULL;
7659 kern_return_t kr = KERN_FAILURE;
7660 int error = EACCES;
7661 boolean_t unexpected_failure = FALSE;
7662 struct cs_blob *csb;
7663 boolean_t require_success = FALSE;
7664 int spawn = (imgp->ip_flags & IMGPF_SPAWN);
7665 const int vfexec = 0;
7666 os_reason_t signature_failure_reason = OS_REASON_NULL;
7667
7668 /*
7669 * Override inherited code signing flags with the
7670 * ones for the process that is being successfully
7671 * loaded
7672 */
7673 proc_lock(p);
7674 proc_csflags_update(p, imgp->ip_csflags);
7675 proc_unlock(p);
7676
7677 /* Set the switch_protect flag on the map */
7678 if (proc_getcsflags(p) & (CS_HARD | CS_KILL)) {
7679 vm_map_switch_protect(get_task_map(proc_task(p)), TRUE);
7680 }
7681 /* set the cs_enforced flags in the map */
7682 if (proc_getcsflags(p) & CS_ENFORCEMENT) {
7683 vm_map_cs_enforcement_set(get_task_map(proc_task(p)), TRUE);
7684 } else {
7685 vm_map_cs_enforcement_set(get_task_map(proc_task(p)), FALSE);
7686 }
7687
7688 /*
7689 * image activation may be failed due to policy
7690 * which is unexpected but security framework does not
7691 * approve of exec, kill and return immediately.
7692 */
7693 if (imgp->ip_mac_return != 0) {
7694 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7695 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY, 0, 0);
7696 signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_SECURITY_POLICY);
7697 error = imgp->ip_mac_return;
7698 unexpected_failure = TRUE;
7699 goto done;
7700 }
7701
7702 if (imgp->ip_cs_error != OS_REASON_NULL) {
7703 signature_failure_reason = imgp->ip_cs_error;
7704 imgp->ip_cs_error = OS_REASON_NULL;
7705 error = EACCES;
7706 goto done;
7707 }
7708
7709 /* call the launch constraints hook */
7710 os_reason_t launch_constraint_reason;
7711 if ((error = mac_proc_check_launch_constraints(p, imgp, &launch_constraint_reason)) != 0) {
7712 signature_failure_reason = launch_constraint_reason;
7713 goto done;
7714 }
7715
7716 #if XNU_TARGET_OS_OSX
7717 /* Check for platform passed in spawn attr if iOS binary is being spawned */
7718 if (proc_platform(p) == PLATFORM_IOS) {
7719 struct _posix_spawnattr *psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
7720 if (psa == NULL || psa->psa_platform == 0) {
7721 boolean_t no_sandbox_entitled = FALSE;
7722 #if DEBUG || DEVELOPMENT
7723 /*
7724 * Allow iOS binaries to spawn on internal systems
7725 * if no-sandbox entitlement is present of unentitled_ios_sim_launch
7726 * boot-arg set to true
7727 */
7728 if (unentitled_ios_sim_launch) {
7729 no_sandbox_entitled = TRUE;
7730 } else {
7731 no_sandbox_entitled = IOVnodeHasEntitlement(imgp->ip_vp,
7732 (int64_t)imgp->ip_arch_offset, "com.apple.private.security.no-sandbox");
7733 }
7734 #endif /* DEBUG || DEVELOPMENT */
7735 if (!no_sandbox_entitled) {
7736 signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7737 EXEC_EXIT_REASON_WRONG_PLATFORM);
7738 error = EACCES;
7739 goto done;
7740 }
7741 printf("Allowing spawn of iOS binary %s since it has "
7742 "com.apple.private.security.no-sandbox entitlement or unentitled_ios_sim_launch "
7743 "boot-arg set to true\n", p->p_name);
7744 } else if (psa->psa_platform != PLATFORM_IOS) {
7745 /* Simulator binary spawned with wrong platform */
7746 signature_failure_reason = os_reason_create(OS_REASON_EXEC,
7747 EXEC_EXIT_REASON_WRONG_PLATFORM);
7748 error = EACCES;
7749 goto done;
7750 } else {
7751 printf("Allowing spawn of iOS binary %s since correct platform was passed in spawn\n",
7752 p->p_name);
7753 }
7754 }
7755 #endif /* XNU_TARGET_OS_OSX */
7756
7757 /* If the code signature came through the image activation path, we skip the
7758 * taskgated / externally attached path. */
7759 if (imgp->ip_csflags & CS_SIGNED) {
7760 error = 0;
7761 goto done;
7762 }
7763
7764 /* The rest of the code is for signatures that either already have been externally
7765 * attached (likely, but not necessarily by a previous run through the taskgated
7766 * path), or that will now be attached by taskgated. */
7767
7768 kr = task_get_task_access_port(proc_task(p), &port);
7769 if (KERN_SUCCESS != kr || !IPC_PORT_VALID(port)) {
7770 error = 0;
7771 if (require_success) {
7772 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7773 proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT, 0, 0);
7774 signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASK_ACCESS_PORT);
7775 error = EACCES;
7776 }
7777 goto done;
7778 }
7779
7780 /*
7781 * taskgated returns KERN_SUCCESS if it has completed its work
7782 * and the exec should continue, KERN_FAILURE if the exec should
7783 * fail, or it may error out with different error code in an
7784 * event of mig failure (e.g. process was signalled during the
7785 * rpc call, taskgated died, mig server died etc.).
7786 */
7787
7788 kr = __EXEC_WAITING_ON_TASKGATED_CODE_SIGNATURE_UPCALL__(port, proc_getpid(p));
7789 switch (kr) {
7790 case KERN_SUCCESS:
7791 error = 0;
7792 break;
7793 case KERN_FAILURE:
7794 error = EACCES;
7795
7796 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7797 proc_getpid(p), OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG, 0, 0);
7798 signature_failure_reason = os_reason_create(OS_REASON_CODESIGNING, CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
7799 goto done;
7800 default:
7801 error = EACCES;
7802
7803 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
7804 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER, 0, 0);
7805 signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_TASKGATED_OTHER);
7806 unexpected_failure = TRUE;
7807 goto done;
7808 }
7809
7810 /* Only do this if exec_resettextvp() did not fail */
7811 if (p->p_textvp != NULLVP) {
7812 csb = ubc_cs_blob_get(p->p_textvp, -1, -1, p->p_textoff);
7813
7814 if (csb != NULL) {
7815 /* As the enforcement we can do here is very limited, we only allow things that
7816 * are the only reason why this code path still exists:
7817 * Adhoc signed non-platform binaries without special cs_flags and without any
7818 * entitlements (unrestricted ones still pass AMFI). */
7819 if (
7820 /* Revalidate the blob if necessary through bumped generation count. */
7821 (ubc_cs_generation_check(p->p_textvp) == 0 ||
7822 ubc_cs_blob_revalidate(p->p_textvp, csb, imgp, 0, proc_platform(p)) == 0) &&
7823 /* Only CS_ADHOC, no CS_KILL, CS_HARD etc. */
7824 (csb->csb_flags & CS_ALLOWED_MACHO) == CS_ADHOC &&
7825 /* If it has a CMS blob, it's not adhoc. The CS_ADHOC flag can lie. */
7826 csblob_find_blob_bytes((const uint8_t *)csb->csb_mem_kaddr, csb->csb_mem_size,
7827 CSSLOT_SIGNATURESLOT,
7828 CSMAGIC_BLOBWRAPPER) == NULL &&
7829 /* It could still be in a trust cache (unlikely with CS_ADHOC), or a magic path. */
7830 csb->csb_platform_binary == 0 &&
7831 /* No entitlements, not even unrestricted ones. */
7832 csb->csb_entitlements_blob == NULL &&
7833 csb->csb_der_entitlements_blob == NULL) {
7834 proc_lock(p);
7835 proc_csflags_set(p, CS_SIGNED | CS_VALID);
7836 proc_unlock(p);
7837 } else {
7838 uint8_t cdhash[CS_CDHASH_LEN];
7839 char cdhash_string[CS_CDHASH_STRING_SIZE];
7840 proc_getcdhash(p, cdhash);
7841 cdhash_to_string(cdhash_string, cdhash);
7842 printf("ignoring detached code signature on '%s' with cdhash '%s' "
7843 "because it is invalid, or not a simple adhoc signature.\n",
7844 p->p_name, cdhash_string);
7845 }
7846 }
7847 }
7848
7849 done:
7850 if (0 == error) {
7851 /*
7852 * Update the new process's signature-dependent process state.
7853 * state.
7854 */
7855
7856 error = proc_process_signature(p, &signature_failure_reason);
7857 }
7858
7859 if (0 == error) {
7860 /*
7861 * Update the new main thread's signature-dependent thread
7862 * state. This was also called when the thread was created,
7863 * but for the main thread the signature was not yet attached
7864 * at that time.
7865 */
7866 kr = thread_process_signature(imgp->ip_new_thread, proc_get_task_raw(p));
7867
7868 if (kr != KERN_SUCCESS) {
7869 error = EINVAL;
7870 signature_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_MACHINE_THREAD);
7871 }
7872 }
7873
7874 if (0 == error) {
7875 /* The process's code signature related properties are
7876 * fully set up, so this is an opportune moment to log
7877 * platform binary execution, if desired. */
7878 if (platform_exec_logging != 0 && csproc_get_platform_binary(p)) {
7879 uint8_t cdhash[CS_CDHASH_LEN];
7880 char cdhash_string[CS_CDHASH_STRING_SIZE];
7881 proc_getcdhash(p, cdhash);
7882 cdhash_to_string(cdhash_string, cdhash);
7883
7884 os_log(peLog, "CS Platform Exec Logging: Executing platform signed binary "
7885 "'%s' with cdhash %s\n", p->p_name, cdhash_string);
7886 }
7887 } else {
7888 if (!unexpected_failure) {
7889 proc_csflags_set(p, CS_KILLED);
7890 }
7891 /* make very sure execution fails */
7892 if (vfexec || spawn) {
7893 assert(signature_failure_reason != OS_REASON_NULL);
7894 psignal_vfork_with_reason(p, proc_task(p), imgp->ip_new_thread,
7895 SIGKILL, signature_failure_reason);
7896 signature_failure_reason = OS_REASON_NULL;
7897 error = 0;
7898 } else {
7899 assert(signature_failure_reason != OS_REASON_NULL);
7900 psignal_with_reason(p, SIGKILL, signature_failure_reason);
7901 signature_failure_reason = OS_REASON_NULL;
7902 }
7903 }
7904
7905 if (port != IPC_PORT_NULL) {
7906 ipc_port_release_send(port);
7907 }
7908
7909 /* If we hit this, we likely would have leaked an exit reason */
7910 assert(signature_failure_reason == OS_REASON_NULL);
7911 return error;
7912 }
7913
7914 /*
7915 * Typically as soon as we start executing this process, the
7916 * first instruction will trigger a VM fault to bring the text
7917 * pages (as executable) into the address space, followed soon
7918 * thereafter by dyld data structures (for dynamic executable).
7919 * To optimize this, as well as improve support for hardware
7920 * debuggers that can only access resident pages present
7921 * in the process' page tables, we prefault some pages if
7922 * possible. Errors are non-fatal.
7923 */
7924 #ifndef PREVENT_CALLER_STACK_USE
7925 #define PREVENT_CALLER_STACK_USE __attribute__((noinline))
7926 #endif
7927
7928 /*
7929 * Prefaulting dyld data does not work (rdar://76621401)
7930 */
7931 #define FIXED_76621401 0
7932 static void PREVENT_CALLER_STACK_USE
exec_prefault_data(__unused proc_t p,__unused struct image_params * imgp,__unused load_result_t * load_result)7933 exec_prefault_data(
7934 __unused proc_t p,
7935 __unused struct image_params *imgp,
7936 __unused load_result_t *load_result)
7937 {
7938 #if FIXED_76621401
7939 int ret;
7940 size_t expected_all_image_infos_size;
7941 #endif /* FIXED_76621401 */
7942 kern_return_t kr;
7943
7944 /*
7945 * Prefault executable or dyld entry point.
7946 */
7947 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7948 DEBUG4K_LOAD("entry_point 0x%llx\n", (uint64_t)load_result->entry_point);
7949 }
7950 kr = vm_fault(current_map(),
7951 vm_map_trunc_page(load_result->entry_point,
7952 vm_map_page_mask(current_map())),
7953 VM_PROT_READ | VM_PROT_EXECUTE,
7954 FALSE, VM_KERN_MEMORY_NONE,
7955 THREAD_UNINT, NULL, 0);
7956 if (kr != KERN_SUCCESS) {
7957 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);
7958 }
7959
7960 #if FIXED_76621401
7961 if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
7962 expected_all_image_infos_size = sizeof(struct user64_dyld_all_image_infos);
7963 } else {
7964 expected_all_image_infos_size = sizeof(struct user32_dyld_all_image_infos);
7965 }
7966
7967 /* Decode dyld anchor structure from <mach-o/dyld_images.h> */
7968 if (load_result->dynlinker &&
7969 load_result->all_image_info_addr &&
7970 load_result->all_image_info_size >= expected_all_image_infos_size) {
7971 union {
7972 struct user64_dyld_all_image_infos infos64;
7973 struct user32_dyld_all_image_infos infos32;
7974 } all_image_infos;
7975
7976 /*
7977 * Pre-fault to avoid copyin() going through the trap handler
7978 * and recovery path.
7979 */
7980 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
7981 DEBUG4K_LOAD("all_image_info_addr 0x%llx\n", load_result->all_image_info_addr);
7982 }
7983 kr = vm_fault(current_map(),
7984 vm_map_trunc_page(load_result->all_image_info_addr,
7985 vm_map_page_mask(current_map())),
7986 VM_PROT_READ | VM_PROT_WRITE,
7987 FALSE, VM_KERN_MEMORY_NONE,
7988 THREAD_UNINT, NULL, 0);
7989 if (kr != KERN_SUCCESS) {
7990 // 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);
7991 }
7992 if ((load_result->all_image_info_addr & PAGE_MASK) + expected_all_image_infos_size > PAGE_SIZE) {
7993 /* all_image_infos straddles a page */
7994 kr = vm_fault(current_map(),
7995 vm_map_trunc_page(load_result->all_image_info_addr + expected_all_image_infos_size - 1,
7996 vm_map_page_mask(current_map())),
7997 VM_PROT_READ | VM_PROT_WRITE,
7998 FALSE, VM_KERN_MEMORY_NONE,
7999 THREAD_UNINT, NULL, 0);
8000 if (kr != KERN_SUCCESS) {
8001 // 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);
8002 }
8003 }
8004
8005 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8006 DEBUG4K_LOAD("copyin(0x%llx, 0x%lx)\n", load_result->all_image_info_addr, expected_all_image_infos_size);
8007 }
8008 ret = copyin((user_addr_t)load_result->all_image_info_addr,
8009 &all_image_infos,
8010 expected_all_image_infos_size);
8011 if (ret == 0 && all_image_infos.infos32.version >= DYLD_ALL_IMAGE_INFOS_ADDRESS_MINIMUM_VERSION) {
8012 user_addr_t notification_address;
8013 user_addr_t dyld_image_address;
8014 user_addr_t dyld_version_address;
8015 user_addr_t dyld_all_image_infos_address;
8016 user_addr_t dyld_slide_amount;
8017
8018 if (imgp->ip_flags & IMGPF_IS_64BIT_ADDR) {
8019 notification_address = (user_addr_t)all_image_infos.infos64.notification;
8020 dyld_image_address = (user_addr_t)all_image_infos.infos64.dyldImageLoadAddress;
8021 dyld_version_address = (user_addr_t)all_image_infos.infos64.dyldVersion;
8022 dyld_all_image_infos_address = (user_addr_t)all_image_infos.infos64.dyldAllImageInfosAddress;
8023 } else {
8024 notification_address = all_image_infos.infos32.notification;
8025 dyld_image_address = all_image_infos.infos32.dyldImageLoadAddress;
8026 dyld_version_address = all_image_infos.infos32.dyldVersion;
8027 dyld_all_image_infos_address = all_image_infos.infos32.dyldAllImageInfosAddress;
8028 }
8029
8030 /*
8031 * dyld statically sets up the all_image_infos in its Mach-O
8032 * binary at static link time, with pointers relative to its default
8033 * load address. Since ASLR might slide dyld before its first
8034 * instruction is executed, "dyld_slide_amount" tells us how far
8035 * dyld was loaded compared to its default expected load address.
8036 * All other pointers into dyld's image should be adjusted by this
8037 * amount. At some point later, dyld will fix up pointers to take
8038 * into account the slide, at which point the all_image_infos_address
8039 * field in the structure will match the runtime load address, and
8040 * "dyld_slide_amount" will be 0, if we were to consult it again.
8041 */
8042
8043 dyld_slide_amount = (user_addr_t)load_result->all_image_info_addr - dyld_all_image_infos_address;
8044
8045 #if 0
8046 kprintf("exec_prefault: 0x%016llx 0x%08x 0x%016llx 0x%016llx 0x%016llx 0x%016llx\n",
8047 (uint64_t)load_result->all_image_info_addr,
8048 all_image_infos.infos32.version,
8049 (uint64_t)notification_address,
8050 (uint64_t)dyld_image_address,
8051 (uint64_t)dyld_version_address,
8052 (uint64_t)dyld_all_image_infos_address);
8053 #endif
8054
8055 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8056 DEBUG4K_LOAD("notification_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)notification_address, (uint64_t)dyld_slide_amount);
8057 }
8058 kr = vm_fault(current_map(),
8059 vm_map_trunc_page(notification_address + dyld_slide_amount,
8060 vm_map_page_mask(current_map())),
8061 VM_PROT_READ | VM_PROT_EXECUTE,
8062 FALSE, VM_KERN_MEMORY_NONE,
8063 THREAD_UNINT, NULL, 0);
8064 if (kr != KERN_SUCCESS) {
8065 // 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);
8066 }
8067 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8068 DEBUG4K_LOAD("dyld_image_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_image_address, (uint64_t)dyld_slide_amount);
8069 }
8070 kr = vm_fault(current_map(),
8071 vm_map_trunc_page(dyld_image_address + dyld_slide_amount,
8072 vm_map_page_mask(current_map())),
8073 VM_PROT_READ | VM_PROT_EXECUTE,
8074 FALSE, VM_KERN_MEMORY_NONE,
8075 THREAD_UNINT, NULL, 0);
8076 if (kr != KERN_SUCCESS) {
8077 // 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);
8078 }
8079 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8080 DEBUG4K_LOAD("dyld_version_address 0x%llx dyld_slide_amount 0x%llx\n", (uint64_t)dyld_version_address, (uint64_t)dyld_slide_amount);
8081 }
8082 kr = vm_fault(current_map(),
8083 vm_map_trunc_page(dyld_version_address + dyld_slide_amount,
8084 vm_map_page_mask(current_map())),
8085 VM_PROT_READ,
8086 FALSE, VM_KERN_MEMORY_NONE,
8087 THREAD_UNINT, NULL, 0);
8088 if (kr != KERN_SUCCESS) {
8089 // 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);
8090 }
8091 if (vm_map_page_shift(current_map()) < (int)PAGE_SHIFT) {
8092 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);
8093 }
8094 kr = vm_fault(current_map(),
8095 vm_map_trunc_page(dyld_all_image_infos_address + dyld_slide_amount,
8096 vm_map_page_mask(current_map())),
8097 VM_PROT_READ | VM_PROT_WRITE,
8098 FALSE, VM_KERN_MEMORY_NONE,
8099 THREAD_UNINT, NULL, 0);
8100 if (kr != KERN_SUCCESS) {
8101 // 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);
8102 }
8103 }
8104 }
8105 #endif /* FIXED_76621401 */
8106 }
8107
8108 static int
8109 sysctl_libmalloc_experiments SYSCTL_HANDLER_ARGS
8110 {
8111 #pragma unused(oidp, arg2, req)
8112 int changed;
8113 errno_t error;
8114 uint64_t value = os_atomic_load_wide(&libmalloc_experiment_factors, relaxed);
8115
8116 error = sysctl_io_number(req, value, sizeof(value), &value, &changed);
8117 if (error) {
8118 return error;
8119 }
8120
8121 if (changed) {
8122 os_atomic_store_wide(&libmalloc_experiment_factors, value, relaxed);
8123 }
8124
8125 return 0;
8126 }
8127
8128 EXPERIMENT_FACTOR_PROC(_kern, libmalloc_experiments, CTLTYPE_QUAD | CTLFLAG_RW, 0, 0, &sysctl_libmalloc_experiments, "A", "");
8129
8130 SYSCTL_NODE(_kern, OID_AUTO, sec_transition,
8131 CTLFLAG_RD | CTLFLAG_LOCKED, 0, "sec_transition");
8132
8133
8134 SYSCTL_INT(_kern_sec_transition, OID_AUTO, available,
8135 CTLFLAG_RD | CTLFLAG_LOCKED, (int *)NULL, 0, "");
8136
8137