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 /*
29 * Copyright (C) 1988, 1989, NeXT, Inc.
30 *
31 * File: kern/mach_loader.c
32 * Author: Avadis Tevanian, Jr.
33 *
34 * Mach object file loader (kernel version, for now).
35 *
36 * 21-Jul-88 Avadis Tevanian, Jr. (avie) at NeXT
37 * Started.
38 */
39
40 #include <sys/param.h>
41 #include <sys/vnode_internal.h>
42 #include <sys/uio.h>
43 #include <sys/namei.h>
44 #include <sys/proc_internal.h>
45 #include <sys/kauth.h>
46 #include <sys/stat.h>
47 #include <sys/malloc.h>
48 #include <sys/mount_internal.h>
49 #include <sys/fcntl.h>
50 #include <sys/file_internal.h>
51 #include <sys/ubc_internal.h>
52 #include <sys/imgact.h>
53 #include <sys/codesign.h>
54 #include <sys/proc_uuid_policy.h>
55 #include <sys/reason.h>
56 #include <sys/kdebug.h>
57 #include <sys/spawn_internal.h>
58
59 #include <mach/mach_types.h>
60 #include <mach/vm_map.h> /* vm_allocate() */
61 #include <mach/mach_vm.h> /* mach_vm_allocate() */
62 #include <mach/vm_statistics.h>
63 #include <mach/task.h>
64 #include <mach/thread_act.h>
65
66 #include <machine/vmparam.h>
67 #include <machine/exec.h>
68 #include <machine/pal_routines.h>
69
70 #include <kern/ast.h>
71 #include <kern/kern_types.h>
72 #include <kern/cpu_number.h>
73 #include <kern/mach_loader.h>
74 #include <kern/mach_fat.h>
75 #include <kern/kalloc.h>
76 #include <kern/task.h>
77 #include <kern/thread.h>
78 #include <kern/page_decrypt.h>
79
80 #include <mach-o/fat.h>
81 #include <mach-o/loader.h>
82
83 #include <vm/pmap.h>
84 #include <vm/vm_map_xnu.h>
85 #include <vm/vm_kern_xnu.h>
86 #include <vm/vm_pager_xnu.h>
87 #include <vm/vnode_pager.h>
88 #include <vm/vm_protos.h>
89 #include <vm/vm_shared_region.h>
90 #include <IOKit/IOReturn.h> /* for kIOReturnNotPrivileged */
91 #include <IOKit/IOBSD.h> /* for IOVnodeHasEntitlement */
92
93 #include <os/log.h>
94 #include <os/overflow.h>
95
96 #include "kern_exec_internal.h"
97
98
99
100 /* An empty load_result_t */
101 static const load_result_t load_result_null = {
102 .mach_header = MACH_VM_MIN_ADDRESS,
103 .entry_point = MACH_VM_MIN_ADDRESS,
104 .user_stack = MACH_VM_MIN_ADDRESS,
105 .user_stack_size = 0,
106 .user_stack_alloc = MACH_VM_MIN_ADDRESS,
107 .user_stack_alloc_size = 0,
108 .all_image_info_addr = MACH_VM_MIN_ADDRESS,
109 .all_image_info_size = 0,
110 .thread_count = 0,
111 .unixproc = 0,
112 .dynlinker = 0,
113 .needs_dynlinker = 0,
114 .validentry = 0,
115 .using_lcmain = 0,
116 .is_64bit_addr = 0,
117 .is_64bit_data = 0,
118 .custom_stack = 0,
119 .csflags = 0,
120 .has_pagezero = 0,
121 .uuid = { 0 },
122 .min_vm_addr = MACH_VM_MAX_ADDRESS,
123 .max_vm_addr = MACH_VM_MIN_ADDRESS,
124 .ro_vm_start = MACH_VM_MIN_ADDRESS,
125 .ro_vm_end = MACH_VM_MIN_ADDRESS,
126 .cs_end_offset = 0,
127 .threadstate = NULL,
128 .threadstate_sz = 0,
129 .is_rosetta = 0,
130 .dynlinker_ro_vm_start = 0,
131 .dynlinker_ro_vm_end = 0,
132 .dynlinker_mach_header = MACH_VM_MIN_ADDRESS,
133 .dynlinker_fd = -1,
134 };
135
136 /*
137 * Prototypes of static functions.
138 */
139 static load_return_t
140 parse_machfile(
141 struct vnode *vp,
142 vm_map_t map,
143 thread_t thread,
144 struct mach_header *header,
145 off_t file_offset,
146 off_t macho_size,
147 int depth,
148 int64_t slide,
149 int64_t dyld_slide,
150 load_result_t *result,
151 load_result_t *binresult,
152 struct image_params *imgp
153 );
154
155 static load_return_t
156 load_segment(
157 struct load_command *lcp,
158 uint32_t filetype,
159 void *control,
160 off_t pager_offset,
161 off_t macho_size,
162 struct vnode *vp,
163 vm_map_t map,
164 int64_t slide,
165 load_result_t *result,
166 struct image_params *imgp
167 );
168
169 static load_return_t
170 load_uuid(
171 struct uuid_command *uulp,
172 char *command_end,
173 load_result_t *result
174 );
175
176 static load_return_t
177 load_version(
178 struct version_min_command *vmc,
179 boolean_t *found_version_cmd,
180 struct image_params *imgp,
181 load_result_t *result
182 );
183
184 static load_return_t
185 load_code_signature(
186 struct linkedit_data_command *lcp,
187 struct vnode *vp,
188 off_t macho_offset,
189 off_t macho_size,
190 cpu_type_t cputype,
191 cpu_subtype_t cpusubtype,
192 load_result_t *result,
193 struct image_params *imgp);
194
195 #if CONFIG_CODE_DECRYPTION
196 static load_return_t
197 set_code_unprotect(
198 struct encryption_info_command *lcp,
199 caddr_t addr,
200 vm_map_t map,
201 int64_t slide,
202 struct vnode *vp,
203 off_t macho_offset,
204 cpu_type_t cputype,
205 cpu_subtype_t cpusubtype);
206 #endif
207
208 static
209 load_return_t
210 load_main(
211 struct entry_point_command *epc,
212 thread_t thread,
213 int64_t slide,
214 load_result_t *result
215 );
216
217 static
218 load_return_t
219 setup_driver_main(
220 thread_t thread,
221 int64_t slide,
222 load_result_t *result
223 );
224
225 static load_return_t
226 load_unixthread(
227 struct thread_command *tcp,
228 thread_t thread,
229 int64_t slide,
230 boolean_t is_x86_64_compat_binary,
231 load_result_t *result
232 );
233
234 static load_return_t
235 load_threadstate(
236 thread_t thread,
237 uint32_t *ts,
238 uint32_t total_size,
239 load_result_t *
240 );
241
242 static load_return_t
243 load_threadstack(
244 thread_t thread,
245 uint32_t *ts,
246 uint32_t total_size,
247 mach_vm_offset_t *user_stack,
248 int *customstack,
249 boolean_t is_x86_64_compat_binary,
250 load_result_t *result
251 );
252
253 static load_return_t
254 load_threadentry(
255 thread_t thread,
256 uint32_t *ts,
257 uint32_t total_size,
258 mach_vm_offset_t *entry_point
259 );
260
261 static load_return_t
262 load_dylinker(
263 struct dylinker_command *lcp,
264 integer_t archbits,
265 vm_map_t map,
266 thread_t thread,
267 int depth,
268 int64_t slide,
269 load_result_t *result,
270 struct image_params *imgp
271 );
272
273
274 #if CONFIG_ROSETTA
275 static load_return_t
276 load_rosetta(
277 vm_map_t map,
278 thread_t thread,
279 load_result_t *result,
280 struct image_params *imgp
281 );
282 #endif
283
284 #if __x86_64__
285 extern int bootarg_no32exec;
286 static boolean_t
287 check_if_simulator_binary(
288 struct image_params *imgp,
289 off_t file_offset,
290 off_t macho_size);
291 #endif
292
293 struct macho_data;
294
295 static load_return_t
296 get_macho_vnode(
297 const char *path,
298 integer_t archbits,
299 struct mach_header *mach_header,
300 off_t *file_offset,
301 off_t *macho_size,
302 struct macho_data *macho_data,
303 struct vnode **vpp,
304 struct image_params *imgp
305 );
306
307 static inline void
widen_segment_command(const struct segment_command * scp32,struct segment_command_64 * scp)308 widen_segment_command(const struct segment_command *scp32,
309 struct segment_command_64 *scp)
310 {
311 scp->cmd = scp32->cmd;
312 scp->cmdsize = scp32->cmdsize;
313 bcopy(scp32->segname, scp->segname, sizeof(scp->segname));
314 scp->vmaddr = scp32->vmaddr;
315 scp->vmsize = scp32->vmsize;
316 scp->fileoff = scp32->fileoff;
317 scp->filesize = scp32->filesize;
318 scp->maxprot = scp32->maxprot;
319 scp->initprot = scp32->initprot;
320 scp->nsects = scp32->nsects;
321 scp->flags = scp32->flags;
322 }
323
324 static void
note_all_image_info_section(const struct segment_command_64 * scp,boolean_t is64,size_t section_size,const void * sections,int64_t slide,load_result_t * result)325 note_all_image_info_section(const struct segment_command_64 *scp,
326 boolean_t is64, size_t section_size, const void *sections,
327 int64_t slide, load_result_t *result)
328 {
329 const union {
330 struct section s32;
331 struct section_64 s64;
332 } *sectionp;
333 unsigned int i;
334
335
336 if (strncmp(scp->segname, "__DATA_DIRTY", sizeof(scp->segname)) != 0 &&
337 strncmp(scp->segname, "__DATA", sizeof(scp->segname)) != 0) {
338 return;
339 }
340 for (i = 0; i < scp->nsects; ++i) {
341 sectionp = (const void *)
342 ((const char *)sections + section_size * i);
343 if (0 == strncmp(sectionp->s64.sectname, "__all_image_info",
344 sizeof(sectionp->s64.sectname))) {
345 result->all_image_info_addr =
346 is64 ? sectionp->s64.addr : sectionp->s32.addr;
347 result->all_image_info_addr += slide;
348 result->all_image_info_size =
349 is64 ? sectionp->s64.size : sectionp->s32.size;
350 return;
351 }
352 }
353 }
354
355 #if __arm64__
356 /*
357 * Allow bypassing some security rules (hard pagezero, no write+execute)
358 * in exchange for better binary compatibility for legacy apps built
359 * before 16KB-alignment was enforced.
360 */
361 const int fourk_binary_compatibility_unsafe = TRUE;
362 #endif /* __arm64__ */
363
364 #if XNU_TARGET_OS_OSX
365
366 /* Determines whether this process may host/run third party plugins. */
367 static inline bool
process_is_plugin_host(struct image_params * imgp,load_result_t * result)368 process_is_plugin_host(struct image_params *imgp, load_result_t *result)
369 {
370 if (imgp->ip_flags & IMGPF_NOJOP) {
371 return false;
372 }
373
374 if (!result->platform_binary) {
375 return false;
376 }
377
378 struct cs_blob *csblob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
379 const char *identity = csblob_get_identity(csblob);
380 if (!identity) {
381 return false;
382 }
383
384 /* Check if override host plugin entitlement is present and posix spawn attribute to disable A keys is passed */
385 if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, OVERRIDE_PLUGIN_HOST_ENTITLEMENT)) {
386 bool ret = imgp->ip_flags & IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
387 if (ret) {
388 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
389 set_proc_name(imgp, p);
390 os_log(OS_LOG_DEFAULT, "%s: running binary \"%s\" in keys-off mode due to posix_spawnattr_disable_ptr_auth_a_keys_np", __func__, p->p_name);
391 }
392 return ret;
393 }
394
395 /* Disabling library validation is a good signal that this process plans to host plugins */
396 const char *const disable_lv_entitlements[] = {
397 "com.apple.security.cs.disable-library-validation",
398 "com.apple.private.cs.automator-plugins",
399 CLEAR_LV_ENTITLEMENT,
400 };
401 for (size_t i = 0; i < ARRAY_COUNT(disable_lv_entitlements); i++) {
402 const char *entitlement = disable_lv_entitlements[i];
403 if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
404 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
405 set_proc_name(imgp, p);
406 os_log(OS_LOG_DEFAULT, "%s: running binary \"%s\" in keys-off mode due to entitlement: %s", __func__, p->p_name, entitlement);
407 return true;
408 }
409 }
410
411 /* From /System/Library/Security/HardeningExceptions.plist */
412 const char *const hardening_exceptions[] = {
413 "com.apple.perl5", /* Scripting engines may load third party code and jit*/
414 "com.apple.perl", /* Scripting engines may load third party code and jit*/
415 "org.python.python", /* Scripting engines may load third party code and jit*/
416 "com.apple.expect", /* Scripting engines may load third party code and jit*/
417 "com.tcltk.wish", /* Scripting engines may load third party code and jit*/
418 "com.tcltk.tclsh", /* Scripting engines may load third party code and jit*/
419 "com.apple.ruby", /* Scripting engines may load third party code and jit*/
420 "com.apple.bash", /* Required for the 'enable' command */
421 "com.apple.zsh", /* Required for the 'zmodload' command */
422 "com.apple.ksh", /* Required for 'builtin' command */
423 };
424 for (size_t i = 0; i < ARRAY_COUNT(hardening_exceptions); i++) {
425 if (strncmp(hardening_exceptions[i], identity, strlen(hardening_exceptions[i])) == 0) {
426 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
427 set_proc_name(imgp, p);
428 os_log(OS_LOG_DEFAULT, "%s: running binary \"%s\" in keys-off mode due to identity: %s", __func__, p->p_name, identity);
429 return true;
430 }
431 }
432
433 return false;
434 }
435 #endif /* XNU_TARGET_OS_OSX */
436
437 load_return_t
load_machfile(struct image_params * imgp,struct mach_header * header,thread_t thread,vm_map_t * mapp,load_result_t * result)438 load_machfile(
439 struct image_params *imgp,
440 struct mach_header *header,
441 thread_t thread,
442 vm_map_t *mapp,
443 load_result_t *result
444 )
445 {
446 struct vnode *vp = imgp->ip_vp;
447 off_t file_offset = imgp->ip_arch_offset;
448 off_t macho_size = imgp->ip_arch_size;
449 off_t total_size = 0;
450 off_t file_size = imgp->ip_vattr->va_data_size;
451 pmap_t pmap = 0; /* protected by create_map */
452 vm_map_t map;
453 load_result_t myresult;
454 load_return_t lret;
455 boolean_t enforce_hard_pagezero = TRUE;
456 int in_exec = (imgp->ip_flags & IMGPF_EXEC);
457 task_t task = current_task();
458 int64_t aslr_page_offset = 0;
459 int64_t dyld_aslr_page_offset = 0;
460 int64_t aslr_section_size = 0;
461 int64_t aslr_section_offset = 0;
462 kern_return_t kret;
463 unsigned int pmap_flags = 0;
464
465 if (os_add_overflow(file_offset, macho_size, &total_size) ||
466 total_size > file_size) {
467 return LOAD_BADMACHO;
468 }
469
470 result->is_64bit_addr = ((imgp->ip_flags & IMGPF_IS_64BIT_ADDR) == IMGPF_IS_64BIT_ADDR);
471 result->is_64bit_data = ((imgp->ip_flags & IMGPF_IS_64BIT_DATA) == IMGPF_IS_64BIT_DATA);
472 #if defined(HAS_APPLE_PAC)
473 pmap_flags |= (imgp->ip_flags & IMGPF_NOJOP) ? PMAP_CREATE_DISABLE_JOP : 0;
474 #endif /* defined(HAS_APPLE_PAC) */
475 #if CONFIG_ROSETTA
476 pmap_flags |= (imgp->ip_flags & IMGPF_ROSETTA) ? PMAP_CREATE_ROSETTA : 0;
477 #endif
478 pmap_flags |= result->is_64bit_addr ? PMAP_CREATE_64BIT : 0;
479
480 task_t ledger_task;
481 if (imgp->ip_new_thread) {
482 ledger_task = get_threadtask(imgp->ip_new_thread);
483 } else {
484 ledger_task = task;
485 }
486
487 #if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
488 if (imgp->ip_px_sa != NULL) {
489 struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
490 if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
491 pmap_flags |= PMAP_CREATE_FORCE_4K_PAGES;
492 }
493 }
494 #endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGE */
495
496 pmap = pmap_create_options(get_task_ledger(ledger_task),
497 (vm_map_size_t) 0,
498 pmap_flags);
499 if (pmap == NULL) {
500 return LOAD_RESOURCE;
501 }
502 map = vm_map_create_options(pmap, 0,
503 vm_compute_max_offset(result->is_64bit_addr),
504 VM_MAP_CREATE_PAGEABLE);
505
506 #if defined(__arm64__)
507 if (result->is_64bit_addr) {
508 /* enforce 16KB alignment of VM map entries */
509 vm_map_set_page_shift(map, SIXTEENK_PAGE_SHIFT);
510 } else {
511 vm_map_set_page_shift(map, page_shift_user32);
512 }
513 #endif /* __arm64__ */
514
515 #if PMAP_CREATE_FORCE_4K_PAGES
516 if (pmap_flags & PMAP_CREATE_FORCE_4K_PAGES) {
517 DEBUG4K_LIFE("***** launching '%s' as 4k *****\n", vp->v_name);
518 vm_map_set_page_shift(map, FOURK_PAGE_SHIFT);
519 }
520 #endif /* PMAP_CREATE_FORCE_4K_PAGES */
521
522 #ifndef CONFIG_ENFORCE_SIGNED_CODE
523 /* This turns off faulting for executable pages, which allows
524 * to circumvent Code Signing Enforcement. The per process
525 * flag (CS_ENFORCEMENT) is not set yet, but we can use the
526 * global flag.
527 */
528 if (!cs_process_global_enforcement() && (header->flags & MH_ALLOW_STACK_EXECUTION)) {
529 vm_map_disable_NX(map);
530 // TODO: Message Trace or log that this is happening
531 }
532 #endif
533
534 /* Forcibly disallow execution from data pages on even if the arch
535 * normally permits it. */
536 if ((header->flags & MH_NO_HEAP_EXECUTION) && !(imgp->ip_flags & IMGPF_ALLOW_DATA_EXEC)) {
537 vm_map_disallow_data_exec(map);
538 }
539
540 /*
541 * Compute a random offset for ASLR, and an independent random offset for dyld.
542 */
543 if (!(imgp->ip_flags & IMGPF_DISABLE_ASLR)) {
544 vm_map_get_max_aslr_slide_section(map, &aslr_section_offset, &aslr_section_size);
545 aslr_section_offset = (random() % aslr_section_offset) * aslr_section_size;
546
547 aslr_page_offset = random();
548 aslr_page_offset = (aslr_page_offset % (vm_map_get_max_aslr_slide_pages(map) - 1)) + 1;
549 aslr_page_offset <<= vm_map_page_shift(map);
550
551 dyld_aslr_page_offset = random();
552 dyld_aslr_page_offset = (dyld_aslr_page_offset %
553 (vm_map_get_max_loader_aslr_slide_pages(map) - 1)) + 1;
554 dyld_aslr_page_offset <<= vm_map_page_shift(map);
555
556 aslr_page_offset += aslr_section_offset;
557 }
558 if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
559 DEBUG4K_LOAD("slide=0x%llx dyld_slide=0x%llx\n", aslr_page_offset, dyld_aslr_page_offset);
560 }
561
562 if (!result) {
563 result = &myresult;
564 }
565
566 *result = load_result_null;
567
568 /*
569 * re-set the bitness on the load result since we cleared the load result above.
570 */
571 result->is_64bit_addr = ((imgp->ip_flags & IMGPF_IS_64BIT_ADDR) == IMGPF_IS_64BIT_ADDR);
572 result->is_64bit_data = ((imgp->ip_flags & IMGPF_IS_64BIT_DATA) == IMGPF_IS_64BIT_DATA);
573
574 lret = parse_machfile(vp, map, thread, header, file_offset, macho_size,
575 0, aslr_page_offset, dyld_aslr_page_offset, result,
576 NULL, imgp);
577
578 if (lret != LOAD_SUCCESS) {
579 imgp->ip_free_map = map;
580 return lret;
581 }
582
583 /*
584 * From now on it's safe to query entitlements via the vnode interface. Let's get figuring
585 * out whether we're a security relevant binary out of the way immediately.
586 */
587 result->is_hardened_process = IOVnodeHasEntitlement(imgp->ip_vp,
588 (int64_t)imgp->ip_arch_offset, "com.apple.developer.hardened-process");
589
590 #if __x86_64__
591 /*
592 * On x86, for compatibility, don't enforce the hard page-zero restriction for 32-bit binaries.
593 */
594 if (!result->is_64bit_addr) {
595 enforce_hard_pagezero = FALSE;
596 }
597
598 /*
599 * For processes with IMGPF_HIGH_BITS_ASLR, add a few random high bits
600 * to the start address for "anywhere" memory allocations.
601 */
602 #define VM_MAP_HIGH_START_BITS_COUNT 8
603 #define VM_MAP_HIGH_START_BITS_SHIFT 27
604 if (result->is_64bit_addr &&
605 (imgp->ip_flags & IMGPF_HIGH_BITS_ASLR)) {
606 int random_bits;
607 vm_map_offset_t high_start;
608
609 random_bits = random();
610 random_bits &= (1 << VM_MAP_HIGH_START_BITS_COUNT) - 1;
611 high_start = (((vm_map_offset_t)random_bits)
612 << VM_MAP_HIGH_START_BITS_SHIFT);
613 vm_map_set_high_start(map, high_start);
614 }
615 #endif /* __x86_64__ */
616
617 /*
618 * Check to see if the page zero is enforced by the map->min_offset.
619 */
620 if (enforce_hard_pagezero &&
621 (vm_map_has_hard_pagezero(map, 0x1000) == FALSE)) {
622 #if __arm64__
623 if (
624 !result->is_64bit_addr && /* not 64-bit address space */
625 !(header->flags & MH_PIE) && /* not PIE */
626 (vm_map_page_shift(map) != FOURK_PAGE_SHIFT ||
627 PAGE_SHIFT != FOURK_PAGE_SHIFT) && /* page size != 4KB */
628 result->has_pagezero && /* has a "soft" page zero */
629 fourk_binary_compatibility_unsafe) {
630 /*
631 * For backwards compatibility of "4K" apps on
632 * a 16K system, do not enforce a hard page zero...
633 */
634 } else
635 #endif /* __arm64__ */
636 {
637 imgp->ip_free_map = map;
638 return LOAD_BADMACHO;
639 }
640 }
641
642 #if __arm64__
643 if (enforce_hard_pagezero && result->is_64bit_addr && (header->cputype == CPU_TYPE_ARM64)) {
644 /* 64 bit ARM binary must have "hard page zero" of 4GB to cover the lower 32 bit address space */
645 if (vm_map_has_hard_pagezero(map, 0x100000000) == FALSE) {
646 imgp->ip_free_map = map;
647 return LOAD_BADMACHO;
648 }
649 }
650 #endif
651
652 vm_commit_pagezero_status(map);
653
654 /*
655 * If this is an exec, then we are going to destroy the old
656 * task, and it's correct to halt it; if it's spawn, the
657 * task is not yet running, and it makes no sense.
658 */
659 if (in_exec) {
660 proc_t p = current_proc();
661 /*
662 * Mark the task as halting and start the other
663 * threads towards terminating themselves. Then
664 * make sure any threads waiting for a process
665 * transition get informed that we are committed to
666 * this transition, and then finally complete the
667 * task halting (wait for threads and then cleanup
668 * task resources).
669 *
670 * NOTE: task_start_halt() makes sure that no new
671 * threads are created in the task during the transition.
672 * We need to mark the workqueue as exiting before we
673 * wait for threads to terminate (at the end of which
674 * we no longer have a prohibition on thread creation).
675 *
676 * Finally, clean up any lingering workqueue data structures
677 * that may have been left behind by the workqueue threads
678 * as they exited (and then clean up the work queue itself).
679 */
680 kret = task_start_halt(task);
681 if (kret != KERN_SUCCESS) {
682 imgp->ip_free_map = map;
683 return LOAD_FAILURE;
684 }
685 proc_transcommit(p, 0);
686 workq_mark_exiting(p);
687 task_complete_halt(task);
688 workq_exit(p);
689
690 /*
691 * Roll up accounting info to new task. The roll up is done after
692 * task_complete_halt to make sure the thread accounting info is
693 * rolled up to current_task.
694 */
695 task_rollup_accounting_info(get_threadtask(thread), task);
696 }
697 *mapp = map;
698
699 #if XNU_TARGET_OS_OSX
700 if (process_is_plugin_host(imgp, result)) {
701 /*
702 * We need to disable security policies for processes
703 * that run third party plugins.
704 */
705 imgp->ip_flags |= IMGPF_3P_PLUGINS;
706 }
707
708 #if __has_feature(ptrauth_calls)
709 /*
710 * arm64e plugin hosts currently run with JOP keys disabled, since they
711 * may need to run arm64 plugins.
712 */
713 if (imgp->ip_flags & IMGPF_3P_PLUGINS) {
714 imgp->ip_flags |= IMGPF_NOJOP;
715 pmap_disable_user_jop(pmap);
716 }
717
718 #if CONFIG_ROSETTA
719 /* Disable JOP keys if the Rosetta runtime being used isn't arm64e */
720 if (result->is_rosetta && (imgp->ip_flags & IMGPF_NOJOP)) {
721 pmap_disable_user_jop(pmap);
722 }
723 #endif /* CONFIG_ROSETTA */
724 #endif /* __has_feature(ptrauth_calls)*/
725 #endif /* XNU_TARGET_OS_OSX */
726
727
728 return LOAD_SUCCESS;
729 }
730
731 int macho_printf = 0;
732 #define MACHO_PRINTF(args) \
733 do { \
734 if (macho_printf) { \
735 printf args; \
736 } \
737 } while (0)
738
739
740 static boolean_t
pie_required(cpu_type_t exectype,cpu_subtype_t execsubtype)741 pie_required(
742 cpu_type_t exectype,
743 cpu_subtype_t execsubtype)
744 {
745 switch (exectype) {
746 case CPU_TYPE_X86_64:
747 return FALSE;
748 case CPU_TYPE_ARM64:
749 return TRUE;
750 case CPU_TYPE_ARM:
751 switch (execsubtype) {
752 case CPU_SUBTYPE_ARM_V7K:
753 return TRUE;
754 }
755 break;
756 }
757 return FALSE;
758 }
759
760 /*
761 * The file size of a mach-o file is limited to 32 bits; this is because
762 * this is the limit on the kalloc() of enough bytes for a mach_header and
763 * the contents of its sizeofcmds, which is currently constrained to 32
764 * bits in the file format itself. We read into the kernel buffer the
765 * commands section, and then parse it in order to parse the mach-o file
766 * format load_command segment(s). We are only interested in a subset of
767 * the total set of possible commands. If "map"==VM_MAP_NULL or
768 * "thread"==THREAD_NULL, do not make permament VM modifications,
769 * just preflight the parse.
770 */
771 static
772 load_return_t
parse_machfile(struct vnode * vp,vm_map_t map,thread_t thread,struct mach_header * header,off_t file_offset,off_t macho_size,int depth,int64_t aslr_offset,int64_t dyld_aslr_offset,load_result_t * result,load_result_t * binresult,struct image_params * imgp)773 parse_machfile(
774 struct vnode *vp,
775 vm_map_t map,
776 thread_t thread,
777 struct mach_header *header,
778 off_t file_offset,
779 off_t macho_size,
780 int depth,
781 int64_t aslr_offset,
782 int64_t dyld_aslr_offset,
783 load_result_t *result,
784 load_result_t *binresult,
785 struct image_params *imgp
786 )
787 {
788 uint32_t ncmds;
789 struct load_command *lcp;
790 struct dylinker_command *dlp = 0;
791 void * control;
792 load_return_t ret = LOAD_SUCCESS;
793 void * addr;
794 vm_size_t alloc_size, cmds_size;
795 size_t offset;
796 size_t oldoffset; /* for overflow check */
797 int pass;
798 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
799 int error;
800 int resid = 0;
801 int spawn = (imgp->ip_flags & IMGPF_SPAWN);
802 size_t mach_header_sz = sizeof(struct mach_header);
803 boolean_t abi64;
804 boolean_t got_code_signatures = FALSE;
805 boolean_t found_header_segment = FALSE;
806 boolean_t found_xhdr = FALSE;
807 boolean_t found_version_cmd = FALSE;
808 int64_t slide = 0;
809 boolean_t dyld_no_load_addr = FALSE;
810 boolean_t is_dyld = FALSE;
811 vm_map_offset_t effective_page_mask = PAGE_MASK;
812 #if __arm64__
813 uint64_t pagezero_end = 0;
814 uint64_t executable_end = 0;
815 uint64_t writable_start = 0;
816 vm_map_size_t effective_page_size;
817
818 effective_page_mask = vm_map_page_mask(map);
819 effective_page_size = vm_map_page_size(map);
820 #endif /* __arm64__ */
821
822 if (header->magic == MH_MAGIC_64 ||
823 header->magic == MH_CIGAM_64) {
824 mach_header_sz = sizeof(struct mach_header_64);
825 }
826
827 /*
828 * Break infinite recursion
829 */
830 if (depth > 2) {
831 return LOAD_FAILURE;
832 }
833
834 depth++;
835
836 /*
837 * Set CS_NO_UNTRUSTED_HELPERS by default; load_dylinker and load_rosetta
838 * will unset it if necessary.
839 */
840 if (depth == 1) {
841 result->csflags |= CS_NO_UNTRUSTED_HELPERS;
842 }
843
844 /*
845 * Check to see if right machine type.
846 */
847 if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != (cpu_type() & ~CPU_ARCH_MASK))
848 ) {
849 return LOAD_BADARCH;
850 }
851
852 if (!grade_binary(header->cputype,
853 header->cpusubtype & ~CPU_SUBTYPE_MASK,
854 header->cpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
855 return LOAD_BADARCH;
856 }
857
858 abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64);
859
860 switch (header->filetype) {
861 case MH_EXECUTE:
862 if (depth != 1 && depth != 3) {
863 return LOAD_FAILURE;
864 }
865 if (header->flags & MH_DYLDLINK) {
866 /* Check properties of dynamic executables */
867 if (!(header->flags & MH_PIE) && pie_required(header->cputype, header->cpusubtype & ~CPU_SUBTYPE_MASK)) {
868 return LOAD_FAILURE;
869 }
870 result->needs_dynlinker = TRUE;
871 } else if (header->cputype == CPU_TYPE_X86_64) {
872 /* x86_64 static binaries allowed */
873 #if CONFIG_ROSETTA
874 } else if (imgp->ip_flags & IMGPF_ROSETTA) {
875 /* Rosetta runtime allowed */
876 #endif /* CONFIG_X86_64_COMPAT */
877 } else {
878 /* Check properties of static executables (disallowed except for development) */
879 #if !(DEVELOPMENT || DEBUG)
880 return LOAD_FAILURE;
881 #endif
882 }
883 break;
884 case MH_DYLINKER:
885 if (depth != 2) {
886 return LOAD_FAILURE;
887 }
888 is_dyld = TRUE;
889 break;
890
891 default:
892 return LOAD_FAILURE;
893 }
894
895 /*
896 * For PIE and dyld, slide everything by the ASLR offset.
897 */
898 if ((header->flags & MH_PIE) || is_dyld) {
899 slide = aslr_offset;
900 }
901
902 /*
903 * Get the pager for the file.
904 */
905 control = ubc_getobject(vp, UBC_FLAGS_NONE);
906
907 /* ensure header + sizeofcmds falls within the file */
908 if (os_add_overflow(mach_header_sz, header->sizeofcmds, &cmds_size) ||
909 (off_t)cmds_size > macho_size ||
910 round_page_overflow(cmds_size, &alloc_size) ||
911 alloc_size > INT_MAX) {
912 return LOAD_BADMACHO;
913 }
914
915 /*
916 * Map the load commands into kernel memory.
917 */
918 addr = kalloc_data(alloc_size, Z_WAITOK);
919 if (addr == NULL) {
920 return LOAD_NOSPACE;
921 }
922
923 error = vn_rdwr(UIO_READ, vp, addr, (int)alloc_size, file_offset,
924 UIO_SYSSPACE, 0, vfs_context_ucred(imgp->ip_vfs_context), &resid, p);
925 if (error) {
926 kfree_data(addr, alloc_size);
927 return LOAD_IOERROR;
928 }
929
930 if (resid) {
931 {
932 /* We must be able to read in as much as the mach_header indicated */
933 kfree_data(addr, alloc_size);
934 return LOAD_BADMACHO;
935 }
936 }
937
938 /*
939 * Scan through the commands, processing each one as necessary.
940 * We parse in three passes through the headers:
941 * 0: determine if TEXT and DATA boundary can be page-aligned, load platform version
942 * 1: thread state, uuid, code signature
943 * 2: segments
944 * 3: dyld, encryption, check entry point
945 */
946
947 boolean_t slide_realign = FALSE;
948 #if __arm64__
949 if (!abi64) {
950 slide_realign = TRUE;
951 }
952 #endif
953
954 for (pass = 0; pass <= 3; pass++) {
955 if (pass == 1) {
956 #if __arm64__
957 boolean_t is_pie;
958 int64_t adjust;
959
960 is_pie = ((header->flags & MH_PIE) != 0);
961 if (pagezero_end != 0 &&
962 pagezero_end < effective_page_size) {
963 /* need at least 1 page for PAGEZERO */
964 adjust = effective_page_size;
965 MACHO_PRINTF(("pagezero boundary at "
966 "0x%llx; adjust slide from "
967 "0x%llx to 0x%llx%s\n",
968 (uint64_t) pagezero_end,
969 slide,
970 slide + adjust,
971 (is_pie
972 ? ""
973 : " BUT NO PIE ****** :-(")));
974 if (is_pie) {
975 slide += adjust;
976 pagezero_end += adjust;
977 executable_end += adjust;
978 writable_start += adjust;
979 }
980 }
981 if (pagezero_end != 0) {
982 result->has_pagezero = TRUE;
983 }
984 if (executable_end == writable_start &&
985 (executable_end & effective_page_mask) != 0 &&
986 (executable_end & FOURK_PAGE_MASK) == 0) {
987 /*
988 * The TEXT/DATA boundary is 4K-aligned but
989 * not page-aligned. Adjust the slide to make
990 * it page-aligned and avoid having a page
991 * with both write and execute permissions.
992 */
993 adjust =
994 (effective_page_size -
995 (executable_end & effective_page_mask));
996 MACHO_PRINTF(("page-unaligned X-W boundary at "
997 "0x%llx; adjust slide from "
998 "0x%llx to 0x%llx%s\n",
999 (uint64_t) executable_end,
1000 slide,
1001 slide + adjust,
1002 (is_pie
1003 ? ""
1004 : " BUT NO PIE ****** :-(")));
1005 if (is_pie) {
1006 slide += adjust;
1007 }
1008 }
1009 #endif /* __arm64__ */
1010
1011 if (dyld_no_load_addr && binresult) {
1012 /*
1013 * The dyld Mach-O does not specify a load address. Try to locate
1014 * it right after the main binary. If binresult == NULL, load
1015 * directly to the given slide.
1016 */
1017 mach_vm_address_t max_vm_addr = binresult->max_vm_addr;
1018 slide = vm_map_round_page(slide + max_vm_addr, effective_page_mask);
1019 }
1020 }
1021
1022 /*
1023 * Check that the entry point is contained in an executable segment
1024 */
1025 if ((pass == 3) && (thread != THREAD_NULL)) {
1026 if (depth == 1 && imgp && (imgp->ip_flags & IMGPF_DRIVER)) {
1027 /* Driver binaries must have driverkit platform */
1028 if (result->ip_platform == PLATFORM_DRIVERKIT) {
1029 /* Driver binaries have no entry point */
1030 ret = setup_driver_main(thread, slide, result);
1031 } else {
1032 ret = LOAD_FAILURE;
1033 }
1034 } else if (!result->using_lcmain && result->validentry == 0) {
1035 ret = LOAD_FAILURE;
1036 }
1037 if (ret != KERN_SUCCESS) {
1038 thread_state_initialize(thread);
1039 break;
1040 }
1041 }
1042
1043 /*
1044 * Check that some segment maps the start of the mach-o file, which is
1045 * needed by the dynamic loader to read the mach headers, etc.
1046 */
1047 if ((pass == 3) && (found_header_segment == FALSE)) {
1048 ret = LOAD_BADMACHO;
1049 break;
1050 }
1051
1052 /*
1053 * Loop through each of the load_commands indicated by the
1054 * Mach-O header; if an absurd value is provided, we just
1055 * run off the end of the reserved section by incrementing
1056 * the offset too far, so we are implicitly fail-safe.
1057 */
1058 offset = mach_header_sz;
1059 ncmds = header->ncmds;
1060
1061 while (ncmds--) {
1062 /* ensure enough space for a minimal load command */
1063 if (offset + sizeof(struct load_command) > cmds_size) {
1064 ret = LOAD_BADMACHO;
1065 break;
1066 }
1067
1068 /*
1069 * Get a pointer to the command.
1070 */
1071 lcp = (struct load_command *)((uintptr_t)addr + offset);
1072 oldoffset = offset;
1073
1074 /*
1075 * Perform prevalidation of the struct load_command
1076 * before we attempt to use its contents. Invalid
1077 * values are ones which result in an overflow, or
1078 * which can not possibly be valid commands, or which
1079 * straddle or exist past the reserved section at the
1080 * start of the image.
1081 */
1082 if (os_add_overflow(offset, lcp->cmdsize, &offset) ||
1083 lcp->cmdsize < sizeof(struct load_command) ||
1084 offset > cmds_size) {
1085 ret = LOAD_BADMACHO;
1086 break;
1087 }
1088
1089 /*
1090 * Act on struct load_command's for which kernel
1091 * intervention is required.
1092 * Note that each load command implementation is expected to validate
1093 * that lcp->cmdsize is large enough to fit its specific struct type
1094 * before dereferencing fields not covered by struct load_command.
1095 */
1096 switch (lcp->cmd) {
1097 case LC_SEGMENT: {
1098 struct segment_command *scp = (struct segment_command *) lcp;
1099 if (scp->cmdsize < sizeof(*scp)) {
1100 ret = LOAD_BADMACHO;
1101 break;
1102 }
1103 if (pass == 0) {
1104 if (is_dyld && scp->vmaddr == 0 && scp->fileoff == 0) {
1105 dyld_no_load_addr = TRUE;
1106 if (!slide_realign) {
1107 /* got what we need, bail early on pass 0 */
1108 continue;
1109 }
1110 }
1111
1112 #if __arm64__
1113 assert(!abi64);
1114
1115 if (scp->initprot == 0 && scp->maxprot == 0 && scp->vmaddr == 0) {
1116 /* PAGEZERO */
1117 if (os_add3_overflow(scp->vmaddr, scp->vmsize, slide, &pagezero_end) || pagezero_end > UINT32_MAX) {
1118 ret = LOAD_BADMACHO;
1119 break;
1120 }
1121 }
1122 if (scp->initprot & VM_PROT_EXECUTE) {
1123 /* TEXT */
1124 if (os_add3_overflow(scp->vmaddr, scp->vmsize, slide, &executable_end) || executable_end > UINT32_MAX) {
1125 ret = LOAD_BADMACHO;
1126 break;
1127 }
1128 }
1129 if (scp->initprot & VM_PROT_WRITE) {
1130 /* DATA */
1131 if (os_add_overflow(scp->vmaddr, slide, &writable_start) || writable_start > UINT32_MAX) {
1132 ret = LOAD_BADMACHO;
1133 break;
1134 }
1135 }
1136 #endif /* __arm64__ */
1137 break;
1138 }
1139
1140 if (pass == 1 && !strncmp(scp->segname, "__XHDR", sizeof(scp->segname))) {
1141 found_xhdr = TRUE;
1142 }
1143
1144 if (pass != 2) {
1145 break;
1146 }
1147
1148 if (abi64) {
1149 /*
1150 * Having an LC_SEGMENT command for the
1151 * wrong ABI is invalid <rdar://problem/11021230>
1152 */
1153 ret = LOAD_BADMACHO;
1154 break;
1155 }
1156
1157 ret = load_segment(lcp,
1158 header->filetype,
1159 control,
1160 file_offset,
1161 macho_size,
1162 vp,
1163 map,
1164 slide,
1165 result,
1166 imgp);
1167 if (ret == LOAD_SUCCESS && scp->fileoff == 0 && scp->filesize > 0) {
1168 /* Enforce a single segment mapping offset zero, with R+X
1169 * protection. */
1170 if (found_header_segment ||
1171 ((scp->initprot & (VM_PROT_READ | VM_PROT_EXECUTE)) != (VM_PROT_READ | VM_PROT_EXECUTE))) {
1172 ret = LOAD_BADMACHO;
1173 break;
1174 }
1175 found_header_segment = TRUE;
1176 }
1177
1178 break;
1179 }
1180 case LC_SEGMENT_64: {
1181 struct segment_command_64 *scp64 = (struct segment_command_64 *) lcp;
1182 if (scp64->cmdsize < sizeof(*scp64)) {
1183 ret = LOAD_BADMACHO;
1184 break;
1185 }
1186 if (pass == 0) {
1187 if (is_dyld && scp64->vmaddr == 0 && scp64->fileoff == 0) {
1188 dyld_no_load_addr = TRUE;
1189 }
1190 /* got what we need, bail early on pass 0 */
1191 continue;
1192 }
1193
1194 if (pass == 1 && !strncmp(scp64->segname, "__XHDR", sizeof(scp64->segname))) {
1195 found_xhdr = TRUE;
1196 }
1197
1198 if (pass != 2) {
1199 break;
1200 }
1201
1202 if (!abi64) {
1203 /*
1204 * Having an LC_SEGMENT_64 command for the
1205 * wrong ABI is invalid <rdar://problem/11021230>
1206 */
1207 ret = LOAD_BADMACHO;
1208 break;
1209 }
1210
1211 ret = load_segment(lcp,
1212 header->filetype,
1213 control,
1214 file_offset,
1215 macho_size,
1216 vp,
1217 map,
1218 slide,
1219 result,
1220 imgp);
1221
1222 if (ret == LOAD_SUCCESS && scp64->fileoff == 0 && scp64->filesize > 0) {
1223 /* Enforce a single segment mapping offset zero, with R+X
1224 * protection. */
1225 if (found_header_segment ||
1226 ((scp64->initprot & (VM_PROT_READ | VM_PROT_EXECUTE)) != (VM_PROT_READ | VM_PROT_EXECUTE))) {
1227 ret = LOAD_BADMACHO;
1228 break;
1229 }
1230 found_header_segment = TRUE;
1231 }
1232
1233 break;
1234 }
1235 case LC_UNIXTHREAD: {
1236 boolean_t is_x86_64_compat_binary = FALSE;
1237 if (pass != 1) {
1238 break;
1239 }
1240 #if CONFIG_ROSETTA
1241 if (depth == 2 && (imgp->ip_flags & IMGPF_ROSETTA)) {
1242 // Ignore dyld, Rosetta will parse it's load commands to get the
1243 // entry point.
1244 result->validentry = 1;
1245 break;
1246 }
1247 #endif
1248 ret = load_unixthread(
1249 (struct thread_command *) lcp,
1250 thread,
1251 slide,
1252 is_x86_64_compat_binary,
1253 result);
1254 break;
1255 }
1256 case LC_MAIN:
1257 if (pass != 1) {
1258 break;
1259 }
1260 if (depth != 1) {
1261 break;
1262 }
1263 ret = load_main(
1264 (struct entry_point_command *) lcp,
1265 thread,
1266 slide,
1267 result);
1268 break;
1269 case LC_LOAD_DYLINKER:
1270 if (pass != 3) {
1271 break;
1272 }
1273 if ((depth == 1) && (dlp == 0)) {
1274 dlp = (struct dylinker_command *)lcp;
1275 } else {
1276 ret = LOAD_FAILURE;
1277 }
1278 break;
1279 case LC_UUID:
1280 if (pass == 1 && depth == 1) {
1281 ret = load_uuid((struct uuid_command *) lcp,
1282 (char *)addr + cmds_size,
1283 result);
1284 }
1285 break;
1286 case LC_CODE_SIGNATURE:
1287 /* CODE SIGNING */
1288 if (pass != 1) {
1289 break;
1290 }
1291
1292 /* pager -> uip ->
1293 * load signatures & store in uip
1294 * set VM object "signed_pages"
1295 */
1296 ret = load_code_signature(
1297 (struct linkedit_data_command *) lcp,
1298 vp,
1299 file_offset,
1300 macho_size,
1301 header->cputype,
1302 header->cpusubtype,
1303 result,
1304 imgp);
1305 if (ret != LOAD_SUCCESS) {
1306 printf("proc %d: load code signature error %d "
1307 "for file \"%s\"\n",
1308 proc_getpid(p), ret, vp->v_name);
1309 /*
1310 * Allow injections to be ignored on devices w/o enforcement enabled
1311 */
1312 if (!cs_process_global_enforcement()) {
1313 ret = LOAD_SUCCESS; /* ignore error */
1314 }
1315 } else {
1316 got_code_signatures = TRUE;
1317 }
1318
1319 if (got_code_signatures) {
1320 unsigned tainted = CS_VALIDATE_TAINTED;
1321 boolean_t valid = FALSE;
1322 vm_size_t off = 0;
1323
1324
1325 if (cs_debug > 10) {
1326 printf("validating initial pages of %s\n", vp->v_name);
1327 }
1328
1329 while (off < alloc_size && ret == LOAD_SUCCESS) {
1330 tainted = CS_VALIDATE_TAINTED;
1331
1332 valid = cs_validate_range(vp,
1333 NULL,
1334 file_offset + off,
1335 (const void *)((uintptr_t)addr + off),
1336 MIN(PAGE_SIZE, cmds_size),
1337 &tainted);
1338 if (!valid || (tainted & CS_VALIDATE_TAINTED)) {
1339 if (cs_debug) {
1340 printf("CODE SIGNING: %s[%d]: invalid initial page at offset %lld validated:%d tainted:%d csflags:0x%x\n",
1341 vp->v_name, proc_getpid(p), (long long)(file_offset + off), valid, tainted, result->csflags);
1342 }
1343 if (cs_process_global_enforcement() ||
1344 (result->csflags & (CS_HARD | CS_KILL | CS_ENFORCEMENT))) {
1345 ret = LOAD_FAILURE;
1346 }
1347 result->csflags &= ~CS_VALID;
1348 }
1349 off += PAGE_SIZE;
1350 }
1351 }
1352
1353 break;
1354 #if CONFIG_CODE_DECRYPTION
1355 case LC_ENCRYPTION_INFO:
1356 case LC_ENCRYPTION_INFO_64:
1357 if (pass != 3) {
1358 break;
1359 }
1360 ret = set_code_unprotect(
1361 (struct encryption_info_command *) lcp,
1362 addr, map, slide, vp, file_offset,
1363 header->cputype, header->cpusubtype);
1364 if (ret != LOAD_SUCCESS) {
1365 os_reason_t load_failure_reason = OS_REASON_NULL;
1366 printf("proc %d: set_code_unprotect() error %d "
1367 "for file \"%s\"\n",
1368 proc_getpid(p), ret, vp->v_name);
1369 /*
1370 * Don't let the app run if it's
1371 * encrypted but we failed to set up the
1372 * decrypter. If the keys are missing it will
1373 * return LOAD_DECRYPTFAIL.
1374 */
1375 if (ret == LOAD_DECRYPTFAIL) {
1376 /* failed to load due to missing FP keys */
1377 proc_lock(p);
1378 p->p_lflag |= P_LTERM_DECRYPTFAIL;
1379 proc_unlock(p);
1380
1381 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1382 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_FAIRPLAY_DECRYPT, 0, 0);
1383 load_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_FAIRPLAY_DECRYPT);
1384 } else {
1385 KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE,
1386 proc_getpid(p), OS_REASON_EXEC, EXEC_EXIT_REASON_DECRYPT, 0, 0);
1387 load_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_DECRYPT);
1388 }
1389
1390 /*
1391 * Don't signal the process if it was forked and in a partially constructed
1392 * state as part of a spawn -- it will just be torn down when the exec fails.
1393 */
1394 if (!spawn) {
1395 assert(load_failure_reason != OS_REASON_NULL);
1396 {
1397 psignal_with_reason(current_proc(), SIGKILL, load_failure_reason);
1398 load_failure_reason = OS_REASON_NULL;
1399 }
1400 } else {
1401 os_reason_free(load_failure_reason);
1402 load_failure_reason = OS_REASON_NULL;
1403 }
1404 }
1405 break;
1406 #endif
1407 case LC_VERSION_MIN_IPHONEOS:
1408 case LC_VERSION_MIN_MACOSX:
1409 case LC_VERSION_MIN_WATCHOS:
1410 case LC_VERSION_MIN_TVOS: {
1411 struct version_min_command *vmc;
1412
1413 if (depth != 1 || pass != 0) {
1414 break;
1415 }
1416 vmc = (struct version_min_command *) lcp;
1417 ret = load_version(vmc, &found_version_cmd, imgp, result);
1418 #if XNU_TARGET_OS_OSX
1419 if (ret == LOAD_SUCCESS) {
1420 if (result->ip_platform == PLATFORM_IOS) {
1421 vm_map_mark_alien(map);
1422 } else {
1423 assert(!vm_map_is_alien(map));
1424 }
1425 }
1426 #endif /* XNU_TARGET_OS_OSX */
1427 break;
1428 }
1429 case LC_BUILD_VERSION: {
1430 if (depth != 1 || pass != 0) {
1431 break;
1432 }
1433 struct build_version_command* bvc = (struct build_version_command*)lcp;
1434 if (bvc->cmdsize < sizeof(*bvc)) {
1435 ret = LOAD_BADMACHO;
1436 break;
1437 }
1438 if (found_version_cmd == TRUE) {
1439 ret = LOAD_BADMACHO;
1440 break;
1441 }
1442 result->ip_platform = bvc->platform;
1443 result->lr_sdk = bvc->sdk;
1444 result->lr_min_sdk = bvc->minos;
1445 found_version_cmd = TRUE;
1446 #if XNU_TARGET_OS_OSX
1447 if (result->ip_platform == PLATFORM_IOS) {
1448 vm_map_mark_alien(map);
1449 } else {
1450 assert(!vm_map_is_alien(map));
1451 }
1452 #endif /* XNU_TARGET_OS_OSX */
1453 break;
1454 }
1455 default:
1456 /* Other commands are ignored by the kernel */
1457 ret = LOAD_SUCCESS;
1458 break;
1459 }
1460 if (ret != LOAD_SUCCESS) {
1461 break;
1462 }
1463 }
1464 if (ret != LOAD_SUCCESS) {
1465 break;
1466 }
1467 }
1468
1469 if (ret == LOAD_SUCCESS) {
1470 if (!got_code_signatures && cs_process_global_enforcement()) {
1471 ret = LOAD_FAILURE;
1472 }
1473
1474 /* Make sure if we need dyld, we got it */
1475 if (result->needs_dynlinker && !dlp) {
1476 ret = LOAD_FAILURE;
1477 }
1478
1479 if ((ret == LOAD_SUCCESS) && (dlp != 0)) {
1480 /*
1481 * load the dylinker, and slide it by the independent DYLD ASLR
1482 * offset regardless of the PIE-ness of the main binary.
1483 */
1484 ret = load_dylinker(dlp, header->cputype, map, thread, depth,
1485 dyld_aslr_offset, result, imgp);
1486 }
1487
1488 #if CONFIG_ROSETTA
1489 if ((ret == LOAD_SUCCESS) && (depth == 1) && (imgp->ip_flags & IMGPF_ROSETTA)) {
1490 ret = load_rosetta(map, thread, result, imgp);
1491 if (ret == LOAD_SUCCESS) {
1492 if (result->user_stack_alloc_size != 0) {
1493 // If a stack allocation is required then add a 4gb gap after the main
1494 // binary/dyld for the worst case static translation size.
1495 mach_vm_size_t reserved_aot_size = 0x100000000;
1496 vm_map_offset_t mask = vm_map_page_mask(map);
1497
1498 mach_vm_address_t vm_end;
1499 if (dlp != 0) {
1500 vm_end = vm_map_round_page(result->dynlinker_max_vm_addr, mask);
1501 } else {
1502 vm_end = vm_map_round_page(result->max_vm_addr, mask);
1503 }
1504
1505 mach_vm_size_t user_stack_size = vm_map_round_page(result->user_stack_alloc_size, mask);
1506 result->user_stack = vm_map_round_page(vm_end + user_stack_size + reserved_aot_size + slide, mask);
1507 }
1508 }
1509 }
1510 #endif
1511
1512 if ((ret == LOAD_SUCCESS) && (depth == 1)) {
1513 if (result->thread_count == 0) {
1514 ret = LOAD_FAILURE;
1515 }
1516 #if CONFIG_ENFORCE_SIGNED_CODE
1517 if (!(result->csflags & CS_NO_UNTRUSTED_HELPERS)) {
1518 ret = LOAD_FAILURE;
1519 }
1520 #endif
1521 }
1522 }
1523
1524 if (ret == LOAD_BADMACHO && found_xhdr) {
1525 ret = LOAD_BADMACHO_UPX;
1526 }
1527
1528 kfree_data(addr, alloc_size);
1529
1530 return ret;
1531 }
1532
1533 load_return_t
validate_potential_simulator_binary(cpu_type_t exectype __unused,struct image_params * imgp __unused,off_t file_offset __unused,off_t macho_size __unused)1534 validate_potential_simulator_binary(
1535 cpu_type_t exectype __unused,
1536 struct image_params *imgp __unused,
1537 off_t file_offset __unused,
1538 off_t macho_size __unused)
1539 {
1540 #if __x86_64__
1541 /* Allow 32 bit exec only for simulator binaries */
1542 if (bootarg_no32exec && imgp != NULL && exectype == CPU_TYPE_X86) {
1543 if (imgp->ip_simulator_binary == IMGPF_SB_DEFAULT) {
1544 boolean_t simulator_binary = check_if_simulator_binary(imgp, file_offset, macho_size);
1545 imgp->ip_simulator_binary = simulator_binary ? IMGPF_SB_TRUE : IMGPF_SB_FALSE;
1546 }
1547
1548 if (imgp->ip_simulator_binary != IMGPF_SB_TRUE) {
1549 return LOAD_BADARCH;
1550 }
1551 }
1552 #endif
1553 return LOAD_SUCCESS;
1554 }
1555
1556 #if __x86_64__
1557 static boolean_t
check_if_simulator_binary(struct image_params * imgp,off_t file_offset,off_t macho_size)1558 check_if_simulator_binary(
1559 struct image_params *imgp,
1560 off_t file_offset,
1561 off_t macho_size)
1562 {
1563 struct mach_header *header;
1564 char *ip_vdata = NULL;
1565 kauth_cred_t cred = NULL;
1566 uint32_t ncmds;
1567 struct load_command *lcp;
1568 boolean_t simulator_binary = FALSE;
1569 void * addr = NULL;
1570 vm_size_t alloc_size, cmds_size;
1571 size_t offset;
1572 proc_t p = current_proc(); /* XXXX */
1573 int error;
1574 int resid = 0;
1575 size_t mach_header_sz = sizeof(struct mach_header);
1576
1577
1578 cred = kauth_cred_proc_ref(p);
1579
1580 /* Allocate page to copyin mach header */
1581 ip_vdata = kalloc_data(PAGE_SIZE, Z_WAITOK | Z_ZERO);
1582 if (ip_vdata == NULL) {
1583 goto bad;
1584 }
1585
1586 /* Read the Mach-O header */
1587 error = vn_rdwr(UIO_READ, imgp->ip_vp, ip_vdata,
1588 PAGE_SIZE, file_offset,
1589 UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED),
1590 cred, &resid, p);
1591 if (error) {
1592 goto bad;
1593 }
1594
1595 header = (struct mach_header *)ip_vdata;
1596
1597 if (header->magic == MH_MAGIC_64 ||
1598 header->magic == MH_CIGAM_64) {
1599 mach_header_sz = sizeof(struct mach_header_64);
1600 }
1601
1602 /* ensure header + sizeofcmds falls within the file */
1603 if (os_add_overflow(mach_header_sz, header->sizeofcmds, &cmds_size) ||
1604 (off_t)cmds_size > macho_size ||
1605 round_page_overflow(cmds_size, &alloc_size) ||
1606 alloc_size > INT_MAX) {
1607 goto bad;
1608 }
1609
1610 /*
1611 * Map the load commands into kernel memory.
1612 */
1613 addr = kalloc_data(alloc_size, Z_WAITOK);
1614 if (addr == NULL) {
1615 goto bad;
1616 }
1617
1618 error = vn_rdwr(UIO_READ, imgp->ip_vp, addr, (int)alloc_size, file_offset,
1619 UIO_SYSSPACE, IO_NODELOCKED, cred, &resid, p);
1620 if (error) {
1621 goto bad;
1622 }
1623
1624 if (resid) {
1625 /* We must be able to read in as much as the mach_header indicated */
1626 goto bad;
1627 }
1628
1629 /*
1630 * Loop through each of the load_commands indicated by the
1631 * Mach-O header; if an absurd value is provided, we just
1632 * run off the end of the reserved section by incrementing
1633 * the offset too far, so we are implicitly fail-safe.
1634 */
1635 offset = mach_header_sz;
1636 ncmds = header->ncmds;
1637
1638 while (ncmds--) {
1639 /* ensure enough space for a minimal load command */
1640 if (offset + sizeof(struct load_command) > cmds_size) {
1641 break;
1642 }
1643
1644 /*
1645 * Get a pointer to the command.
1646 */
1647 lcp = (struct load_command *)((uintptr_t)addr + offset);
1648
1649 /*
1650 * Perform prevalidation of the struct load_command
1651 * before we attempt to use its contents. Invalid
1652 * values are ones which result in an overflow, or
1653 * which can not possibly be valid commands, or which
1654 * straddle or exist past the reserved section at the
1655 * start of the image.
1656 */
1657 if (os_add_overflow(offset, lcp->cmdsize, &offset) ||
1658 lcp->cmdsize < sizeof(struct load_command) ||
1659 offset > cmds_size) {
1660 break;
1661 }
1662
1663 /* Check if its a simulator binary. */
1664 switch (lcp->cmd) {
1665 case LC_VERSION_MIN_WATCHOS:
1666 simulator_binary = TRUE;
1667 break;
1668
1669 case LC_BUILD_VERSION: {
1670 struct build_version_command *bvc;
1671
1672 bvc = (struct build_version_command *) lcp;
1673 if (bvc->cmdsize < sizeof(*bvc)) {
1674 /* unsafe to use this command struct if cmdsize
1675 * validated above is too small for it to fit */
1676 break;
1677 }
1678 if (bvc->platform == PLATFORM_IOSSIMULATOR ||
1679 bvc->platform == PLATFORM_WATCHOSSIMULATOR) {
1680 simulator_binary = TRUE;
1681 }
1682
1683 break;
1684 }
1685
1686 case LC_VERSION_MIN_IPHONEOS: {
1687 simulator_binary = TRUE;
1688 break;
1689 }
1690
1691 default:
1692 /* ignore other load commands */
1693 break;
1694 }
1695
1696 if (simulator_binary == TRUE) {
1697 break;
1698 }
1699 }
1700
1701 bad:
1702 if (ip_vdata) {
1703 kfree_data(ip_vdata, PAGE_SIZE);
1704 }
1705
1706 if (cred) {
1707 kauth_cred_unref(&cred);
1708 }
1709
1710 if (addr) {
1711 kfree_data(addr, alloc_size);
1712 }
1713
1714 return simulator_binary;
1715 }
1716 #endif /* __x86_64__ */
1717
1718 #if CONFIG_CODE_DECRYPTION
1719
1720 #define APPLE_UNPROTECTED_HEADER_SIZE (3 * 4096)
1721
1722 static load_return_t
unprotect_dsmos_segment(uint64_t file_off,uint64_t file_size,struct vnode * vp,off_t macho_offset,vm_map_t map,vm_map_offset_t map_addr,vm_map_size_t map_size)1723 unprotect_dsmos_segment(
1724 uint64_t file_off,
1725 uint64_t file_size,
1726 struct vnode *vp,
1727 off_t macho_offset,
1728 vm_map_t map,
1729 vm_map_offset_t map_addr,
1730 vm_map_size_t map_size)
1731 {
1732 kern_return_t kr;
1733 uint64_t slice_off;
1734
1735 /*
1736 * The first APPLE_UNPROTECTED_HEADER_SIZE bytes (from offset 0 of
1737 * this part of a Universal binary) are not protected...
1738 * The rest needs to be "transformed".
1739 */
1740 slice_off = file_off - macho_offset;
1741 if (slice_off <= APPLE_UNPROTECTED_HEADER_SIZE &&
1742 slice_off + file_size <= APPLE_UNPROTECTED_HEADER_SIZE) {
1743 /* it's all unprotected, nothing to do... */
1744 kr = KERN_SUCCESS;
1745 } else {
1746 if (slice_off <= APPLE_UNPROTECTED_HEADER_SIZE) {
1747 /*
1748 * We start mapping in the unprotected area.
1749 * Skip the unprotected part...
1750 */
1751 uint64_t delta_file;
1752 vm_map_offset_t delta_map;
1753
1754 delta_file = (uint64_t)APPLE_UNPROTECTED_HEADER_SIZE;
1755 delta_file -= slice_off;
1756 if (os_convert_overflow(delta_file, &delta_map)) {
1757 return LOAD_BADMACHO;
1758 }
1759 if (os_add_overflow(map_addr, delta_map, &map_addr)) {
1760 return LOAD_BADMACHO;
1761 }
1762 if (os_sub_overflow(map_size, delta_map, &map_size)) {
1763 return LOAD_BADMACHO;
1764 }
1765 }
1766 /* ... transform the rest of the mapping. */
1767 struct pager_crypt_info crypt_info;
1768 crypt_info.page_decrypt = dsmos_page_transform;
1769 crypt_info.crypt_ops = NULL;
1770 crypt_info.crypt_end = NULL;
1771 #pragma unused(vp, macho_offset)
1772 crypt_info.crypt_ops = (void *)0x2e69cf40;
1773 vm_map_offset_t crypto_backing_offset;
1774 crypto_backing_offset = -1; /* i.e. use map entry's offset */
1775 #if VM_MAP_DEBUG_APPLE_PROTECT
1776 if (vm_map_debug_apple_protect) {
1777 struct proc *p;
1778 p = current_proc();
1779 printf("APPLE_PROTECT: %d[%s] map %p "
1780 "[0x%llx:0x%llx] %s(%s)\n",
1781 proc_getpid(p), p->p_comm, map,
1782 (uint64_t) map_addr,
1783 (uint64_t) (map_addr + map_size),
1784 __FUNCTION__, vp->v_name);
1785 }
1786 #endif /* VM_MAP_DEBUG_APPLE_PROTECT */
1787
1788 /* The DSMOS pager can only be used by apple signed code */
1789 struct cs_blob * blob = csvnode_get_blob(vp, file_off);
1790 if (blob == NULL || !blob->csb_platform_binary || blob->csb_platform_path) {
1791 return LOAD_FAILURE;
1792 }
1793
1794 kr = vm_map_apple_protected(map,
1795 map_addr,
1796 map_addr + map_size,
1797 crypto_backing_offset,
1798 &crypt_info,
1799 CRYPTID_APP_ENCRYPTION);
1800 }
1801
1802 if (kr != KERN_SUCCESS) {
1803 return LOAD_FAILURE;
1804 }
1805 return LOAD_SUCCESS;
1806 }
1807 #else /* CONFIG_CODE_DECRYPTION */
1808 static load_return_t
unprotect_dsmos_segment(__unused uint64_t file_off,__unused uint64_t file_size,__unused struct vnode * vp,__unused off_t macho_offset,__unused vm_map_t map,__unused vm_map_offset_t map_addr,__unused vm_map_size_t map_size)1809 unprotect_dsmos_segment(
1810 __unused uint64_t file_off,
1811 __unused uint64_t file_size,
1812 __unused struct vnode *vp,
1813 __unused off_t macho_offset,
1814 __unused vm_map_t map,
1815 __unused vm_map_offset_t map_addr,
1816 __unused vm_map_size_t map_size)
1817 {
1818 return LOAD_SUCCESS;
1819 }
1820 #endif /* CONFIG_CODE_DECRYPTION */
1821
1822
1823 /*
1824 * map_segment:
1825 * Maps a Mach-O segment.
1826 */
1827 static kern_return_t
map_segment(vm_map_t map,vm_map_offset_t vm_start,vm_map_offset_t vm_end,vm_map_kernel_flags_t vmk_flags,memory_object_control_t control,vm_map_offset_t file_start,vm_map_offset_t file_end,vm_prot_t initprot,vm_prot_t maxprot,load_result_t * result)1828 map_segment(
1829 vm_map_t map,
1830 vm_map_offset_t vm_start,
1831 vm_map_offset_t vm_end,
1832 vm_map_kernel_flags_t vmk_flags,
1833 memory_object_control_t control,
1834 vm_map_offset_t file_start,
1835 vm_map_offset_t file_end,
1836 vm_prot_t initprot,
1837 vm_prot_t maxprot,
1838 load_result_t *result)
1839 {
1840 kern_return_t ret;
1841 vm_map_offset_t effective_page_mask;
1842
1843 if (vm_end < vm_start ||
1844 file_end < file_start) {
1845 return LOAD_BADMACHO;
1846 }
1847 if (vm_end == vm_start ||
1848 file_end == file_start) {
1849 /* nothing to map... */
1850 return LOAD_SUCCESS;
1851 }
1852
1853 effective_page_mask = vm_map_page_mask(map);
1854
1855 if (vm_map_page_aligned(vm_start, effective_page_mask) &&
1856 vm_map_page_aligned(vm_end, effective_page_mask) &&
1857 vm_map_page_aligned(file_start, effective_page_mask) &&
1858 vm_map_page_aligned(file_end, effective_page_mask)) {
1859 /* all page-aligned and map-aligned: proceed */
1860 } else {
1861 /*
1862 * There's no more fourk_pager to handle mis-alignments;
1863 * all binaries should be page-aligned and map-aligned
1864 */
1865 return LOAD_BADMACHO;
1866 }
1867
1868 #if !defined(XNU_TARGET_OS_OSX)
1869 (void) result;
1870 #else /* !defined(XNU_TARGET_OS_OSX) */
1871 /*
1872 * This process doesn't have its new csflags (from
1873 * the image being loaded) yet, so tell VM to override the
1874 * current process's CS_ENFORCEMENT for this mapping.
1875 */
1876 if (result->csflags & CS_ENFORCEMENT) {
1877 vmk_flags.vmkf_cs_enforcement = TRUE;
1878 } else {
1879 vmk_flags.vmkf_cs_enforcement = FALSE;
1880 }
1881 vmk_flags.vmkf_cs_enforcement_override = TRUE;
1882 #endif /* !defined(XNU_TARGET_OS_OSX) */
1883
1884 if (result->is_rosetta && (initprot & VM_PROT_EXECUTE) == VM_PROT_EXECUTE) {
1885 vmk_flags.vmkf_translated_allow_execute = TRUE;
1886 }
1887
1888 if (control != MEMORY_OBJECT_CONTROL_NULL) {
1889 /* no copy-on-read for mapped binaries */
1890 vmk_flags.vmkf_no_copy_on_read = 1;
1891 ret = vm_map_enter_mem_object_control(
1892 map,
1893 &vm_start,
1894 file_end - file_start,
1895 (mach_vm_offset_t)0,
1896 vmk_flags,
1897 control,
1898 file_start,
1899 TRUE, /* copy */
1900 initprot, maxprot,
1901 VM_INHERIT_DEFAULT);
1902 } else {
1903 ret = mach_vm_map_kernel(
1904 map,
1905 &vm_start,
1906 file_end - file_start,
1907 (mach_vm_offset_t)0,
1908 vmk_flags,
1909 IPC_PORT_NULL,
1910 0, /* offset */
1911 TRUE, /* copy */
1912 initprot, maxprot,
1913 VM_INHERIT_DEFAULT);
1914 }
1915 if (ret != KERN_SUCCESS) {
1916 return LOAD_NOSPACE;
1917 }
1918 return LOAD_SUCCESS;
1919 }
1920
1921 static
1922 load_return_t
load_segment(struct load_command * lcp,uint32_t filetype,void * control,off_t pager_offset,off_t macho_size,struct vnode * vp,vm_map_t map,int64_t slide,load_result_t * result,struct image_params * imgp)1923 load_segment(
1924 struct load_command *lcp,
1925 uint32_t filetype,
1926 void * control,
1927 off_t pager_offset,
1928 off_t macho_size,
1929 struct vnode *vp,
1930 vm_map_t map,
1931 int64_t slide,
1932 load_result_t *result,
1933 struct image_params *imgp)
1934 {
1935 struct segment_command_64 segment_command, *scp;
1936 kern_return_t ret;
1937 vm_map_size_t delta_size;
1938 vm_prot_t initprot;
1939 vm_prot_t maxprot;
1940 size_t segment_command_size, total_section_size,
1941 single_section_size;
1942 uint64_t file_offset, file_size;
1943 vm_map_offset_t vm_offset;
1944 size_t vm_size;
1945 vm_map_offset_t vm_start, vm_end, vm_end_aligned;
1946 vm_map_offset_t file_start, file_end;
1947 vm_map_kernel_flags_t vmk_flags;
1948 kern_return_t kr;
1949 boolean_t verbose;
1950 vm_map_size_t effective_page_size;
1951 vm_map_offset_t effective_page_mask;
1952 #if __arm64__
1953 boolean_t fourk_align;
1954 #endif /* __arm64__ */
1955
1956 (void)imgp;
1957
1958 effective_page_size = vm_map_page_size(map);
1959 effective_page_mask = vm_map_page_mask(map);
1960 vmk_flags = VM_MAP_KERNEL_FLAGS_FIXED();
1961
1962 verbose = FALSE;
1963 if (LC_SEGMENT_64 == lcp->cmd) {
1964 segment_command_size = sizeof(struct segment_command_64);
1965 single_section_size = sizeof(struct section_64);
1966 #if __arm64__
1967 /* 64-bit binary: should already be 16K-aligned */
1968 fourk_align = FALSE;
1969
1970 if (vm_map_page_shift(map) == FOURK_PAGE_SHIFT &&
1971 PAGE_SHIFT != FOURK_PAGE_SHIFT) {
1972 fourk_align = TRUE;
1973 verbose = TRUE;
1974 }
1975 #endif /* __arm64__ */
1976 } else {
1977 segment_command_size = sizeof(struct segment_command);
1978 single_section_size = sizeof(struct section);
1979 #if __arm64__
1980 /* 32-bit binary or arm64_32 binary: should already be page-aligned */
1981 fourk_align = FALSE;
1982 #endif /* __arm64__ */
1983 }
1984 if (lcp->cmdsize < segment_command_size) {
1985 DEBUG4K_ERROR("LOAD_BADMACHO cmdsize %d < %zu\n", lcp->cmdsize, segment_command_size);
1986 return LOAD_BADMACHO;
1987 }
1988 total_section_size = lcp->cmdsize - segment_command_size;
1989
1990 if (LC_SEGMENT_64 == lcp->cmd) {
1991 scp = (struct segment_command_64 *)lcp;
1992 } else {
1993 scp = &segment_command;
1994 widen_segment_command((struct segment_command *)lcp, scp);
1995 }
1996
1997 if (verbose) {
1998 MACHO_PRINTF(("+++ load_segment %s "
1999 "vm[0x%llx:0x%llx] file[0x%llx:0x%llx] "
2000 "prot %d/%d flags 0x%x\n",
2001 scp->segname,
2002 (uint64_t)(slide + scp->vmaddr),
2003 (uint64_t)(slide + scp->vmaddr + scp->vmsize),
2004 pager_offset + scp->fileoff,
2005 pager_offset + scp->fileoff + scp->filesize,
2006 scp->initprot,
2007 scp->maxprot,
2008 scp->flags));
2009 }
2010
2011 /*
2012 * Make sure what we get from the file is really ours (as specified
2013 * by macho_size).
2014 */
2015 if (scp->fileoff + scp->filesize < scp->fileoff ||
2016 scp->fileoff + scp->filesize > (uint64_t)macho_size) {
2017 DEBUG4K_ERROR("LOAD_BADMACHO fileoff 0x%llx filesize 0x%llx macho_size 0x%llx\n", scp->fileoff, scp->filesize, (uint64_t)macho_size);
2018 return LOAD_BADMACHO;
2019 }
2020 /*
2021 * Ensure that the number of sections specified would fit
2022 * within the load command size.
2023 */
2024 if (total_section_size / single_section_size < scp->nsects) {
2025 DEBUG4K_ERROR("LOAD_BADMACHO 0x%zx 0x%zx %d\n", total_section_size, single_section_size, scp->nsects);
2026 return LOAD_BADMACHO;
2027 }
2028 /*
2029 * Make sure the segment is page-aligned in the file.
2030 */
2031 if (os_add_overflow(pager_offset, scp->fileoff, &file_offset)) {
2032 DEBUG4K_ERROR("LOAD_BADMACHO file_offset: 0x%llx + 0x%llx\n", pager_offset, scp->fileoff);
2033 return LOAD_BADMACHO;
2034 }
2035 file_size = scp->filesize;
2036 #if __arm64__
2037 if (fourk_align) {
2038 if ((file_offset & FOURK_PAGE_MASK) != 0) {
2039 /*
2040 * we can't mmap() it if it's not at least 4KB-aligned
2041 * in the file
2042 */
2043 DEBUG4K_ERROR("LOAD_BADMACHO file_offset 0x%llx\n", file_offset);
2044 return LOAD_BADMACHO;
2045 }
2046 } else
2047 #endif /* __arm64__ */
2048 if ((file_offset & PAGE_MASK_64) != 0 ||
2049 /* we can't mmap() it if it's not page-aligned in the file */
2050 (file_offset & vm_map_page_mask(map)) != 0) {
2051 /*
2052 * The 1st test would have failed if the system's page size
2053 * was what this process believe is the page size, so let's
2054 * fail here too for the sake of consistency.
2055 */
2056 DEBUG4K_ERROR("LOAD_BADMACHO file_offset 0x%llx\n", file_offset);
2057 return LOAD_BADMACHO;
2058 }
2059
2060 /*
2061 * If we have a code signature attached for this slice
2062 * require that the segments are within the signed part
2063 * of the file.
2064 */
2065 if (result->cs_end_offset &&
2066 result->cs_end_offset < (off_t)scp->fileoff &&
2067 result->cs_end_offset - scp->fileoff < scp->filesize) {
2068 if (cs_debug) {
2069 printf("section outside code signature\n");
2070 }
2071 DEBUG4K_ERROR("LOAD_BADMACHO end_offset 0x%llx fileoff 0x%llx filesize 0x%llx\n", result->cs_end_offset, scp->fileoff, scp->filesize);
2072 return LOAD_BADMACHO;
2073 }
2074
2075 if (os_add_overflow(scp->vmaddr, slide, &vm_offset)) {
2076 if (cs_debug) {
2077 printf("vmaddr too large\n");
2078 }
2079 DEBUG4K_ERROR("LOAD_BADMACHO vmaddr 0x%llx slide 0x%llx vm_offset 0x%llx\n", scp->vmaddr, slide, (uint64_t)vm_offset);
2080 return LOAD_BADMACHO;
2081 }
2082
2083 if (scp->vmsize > SIZE_MAX) {
2084 DEBUG4K_ERROR("LOAD_BADMACHO vmsize 0x%llx\n", scp->vmsize);
2085 return LOAD_BADMACHO;
2086 }
2087
2088 vm_size = (size_t)scp->vmsize;
2089
2090 if (vm_size == 0) {
2091 return LOAD_SUCCESS;
2092 }
2093 if (scp->vmaddr == 0 &&
2094 file_size == 0 &&
2095 vm_size != 0 &&
2096 (scp->initprot & VM_PROT_ALL) == VM_PROT_NONE &&
2097 (scp->maxprot & VM_PROT_ALL) == VM_PROT_NONE) {
2098 if (map == VM_MAP_NULL) {
2099 return LOAD_SUCCESS;
2100 }
2101
2102 /*
2103 * For PIE, extend page zero rather than moving it. Extending
2104 * page zero keeps early allocations from falling predictably
2105 * between the end of page zero and the beginning of the first
2106 * slid segment.
2107 */
2108 /*
2109 * This is a "page zero" segment: it starts at address 0,
2110 * is not mapped from the binary file and is not accessible.
2111 * User-space should never be able to access that memory, so
2112 * make it completely off limits by raising the VM map's
2113 * minimum offset.
2114 */
2115 vm_end = (vm_map_offset_t)(vm_offset + vm_size);
2116 if (vm_end < vm_offset) {
2117 DEBUG4K_ERROR("LOAD_BADMACHO vm_end 0x%llx vm_offset 0x%llx vm_size 0x%llx\n", (uint64_t)vm_end, (uint64_t)vm_offset, (uint64_t)vm_size);
2118 return LOAD_BADMACHO;
2119 }
2120
2121 if (verbose) {
2122 MACHO_PRINTF(("++++++ load_segment: "
2123 "page_zero up to 0x%llx\n",
2124 (uint64_t) vm_end));
2125 }
2126 #if __arm64__
2127 if (fourk_align) {
2128 /* raise min_offset as much as page-alignment allows */
2129 vm_end_aligned = vm_map_trunc_page(vm_end,
2130 effective_page_mask);
2131 } else
2132 #endif /* __arm64__ */
2133 {
2134 vm_end = vm_map_round_page(vm_end,
2135 PAGE_MASK_64);
2136 vm_end_aligned = vm_end;
2137 }
2138 ret = vm_map_raise_min_offset(map,
2139 vm_end_aligned);
2140 if (ret != KERN_SUCCESS) {
2141 DEBUG4K_ERROR("LOAD_FAILURE ret 0x%x\n", ret);
2142 return LOAD_FAILURE;
2143 }
2144 return LOAD_SUCCESS;
2145 } else {
2146 #if !defined(XNU_TARGET_OS_OSX)
2147 /* not PAGEZERO: should not be mapped at address 0 */
2148 if (filetype != MH_DYLINKER && (imgp->ip_flags & IMGPF_ROSETTA) == 0 && scp->vmaddr == 0) {
2149 DEBUG4K_ERROR("LOAD_BADMACHO filetype %d vmaddr 0x%llx\n", filetype, scp->vmaddr);
2150 return LOAD_BADMACHO;
2151 }
2152 #endif /* !defined(XNU_TARGET_OS_OSX) */
2153 }
2154
2155 #if __arm64__
2156 if (fourk_align) {
2157 /* 4K-align */
2158 file_start = vm_map_trunc_page(file_offset,
2159 FOURK_PAGE_MASK);
2160 file_end = vm_map_round_page(file_offset + file_size,
2161 FOURK_PAGE_MASK);
2162 vm_start = vm_map_trunc_page(vm_offset,
2163 FOURK_PAGE_MASK);
2164 vm_end = vm_map_round_page(vm_offset + vm_size,
2165 FOURK_PAGE_MASK);
2166
2167 if (file_offset - file_start > FOURK_PAGE_MASK ||
2168 file_end - file_offset - file_size > FOURK_PAGE_MASK) {
2169 DEBUG4K_ERROR("LOAD_BADMACHO file_start / file_size wrap "
2170 "[0x%llx:0x%llx] -> [0x%llx:0x%llx]\n",
2171 file_offset,
2172 file_offset + file_size,
2173 (uint64_t) file_start,
2174 (uint64_t) file_end);
2175 return LOAD_BADMACHO;
2176 }
2177
2178 if (!strncmp(scp->segname, "__LINKEDIT", 11) &&
2179 page_aligned(file_start) &&
2180 vm_map_page_aligned(file_start, vm_map_page_mask(map)) &&
2181 page_aligned(vm_start) &&
2182 vm_map_page_aligned(vm_start, vm_map_page_mask(map))) {
2183 /* XXX last segment: ignore mis-aligned tail */
2184 file_end = vm_map_round_page(file_end,
2185 effective_page_mask);
2186 vm_end = vm_map_round_page(vm_end,
2187 effective_page_mask);
2188 }
2189 } else
2190 #endif /* __arm64__ */
2191 {
2192 file_start = vm_map_trunc_page(file_offset,
2193 effective_page_mask);
2194 file_end = vm_map_round_page(file_offset + file_size,
2195 effective_page_mask);
2196 vm_start = vm_map_trunc_page(vm_offset,
2197 effective_page_mask);
2198 vm_end = vm_map_round_page(vm_offset + vm_size,
2199 effective_page_mask);
2200
2201 if (file_offset - file_start > effective_page_mask ||
2202 file_end - file_offset - file_size > effective_page_mask) {
2203 DEBUG4K_ERROR("LOAD_BADMACHO file_start / file_size wrap "
2204 "[0x%llx:0x%llx] -> [0x%llx:0x%llx]\n",
2205 file_offset,
2206 file_offset + file_size,
2207 (uint64_t) file_start,
2208 (uint64_t) file_end);
2209 return LOAD_BADMACHO;
2210 }
2211 }
2212
2213 if (vm_start < result->min_vm_addr) {
2214 result->min_vm_addr = vm_start;
2215 }
2216 if (vm_end > result->max_vm_addr) {
2217 result->max_vm_addr = vm_end;
2218 }
2219
2220 if (map == VM_MAP_NULL) {
2221 return LOAD_SUCCESS;
2222 }
2223
2224 if (scp->flags & SG_READ_ONLY) {
2225 /*
2226 * Record the VM start/end of a segment which should
2227 * be RO after fixups. Only __DATA_CONST should
2228 * have this flag.
2229 */
2230 if (result->ro_vm_start != MACH_VM_MIN_ADDRESS ||
2231 result->ro_vm_end != MACH_VM_MIN_ADDRESS) {
2232 DEBUG4K_ERROR("LOAD_BADMACHO segment flags [%x] "
2233 "multiple segments with SG_READ_ONLY flag\n",
2234 scp->flags);
2235 return LOAD_BADMACHO;
2236 }
2237
2238 result->ro_vm_start = vm_start;
2239 result->ro_vm_end = vm_end;
2240 }
2241
2242 if (vm_size > 0) {
2243 #if !__x86_64__
2244 if (!strncmp(scp->segname, "__LINKEDIT", 11)) {
2245 vmk_flags.vmf_permanent = true;
2246 }
2247 #endif /* !__x86_64__ */
2248 initprot = (scp->initprot) & VM_PROT_ALL;
2249 maxprot = (scp->maxprot) & VM_PROT_ALL;
2250 /*
2251 * Map a copy of the file into the address space.
2252 */
2253 if (verbose) {
2254 MACHO_PRINTF(("++++++ load_segment: "
2255 "mapping at vm [0x%llx:0x%llx] of "
2256 "file [0x%llx:0x%llx]\n",
2257 (uint64_t) vm_start,
2258 (uint64_t) vm_end,
2259 (uint64_t) file_start,
2260 (uint64_t) file_end));
2261 }
2262 ret = map_segment(map,
2263 vm_start,
2264 vm_end,
2265 vmk_flags,
2266 control,
2267 file_start,
2268 file_end,
2269 initprot,
2270 maxprot,
2271 result);
2272 if (ret) {
2273 DEBUG4K_ERROR("LOAD_NOSPACE start 0x%llx end 0x%llx ret 0x%x\n", (uint64_t)vm_start, (uint64_t)vm_end, ret);
2274 return LOAD_NOSPACE;
2275 }
2276
2277 #if FIXME
2278 /*
2279 * If the file didn't end on a page boundary,
2280 * we need to zero the leftover.
2281 */
2282 delta_size = map_size - scp->filesize;
2283 if (delta_size > 0) {
2284 void *tmp = kalloc_data(delta_size, Z_WAITOK | Z_ZERO);
2285 int rc;
2286
2287 if (tmp == NULL) {
2288 DEBUG4K_ERROR("LOAD_RESOURCE delta_size 0x%llx ret 0x%x\n", delta_size, ret);
2289 return LOAD_RESOURCE;
2290 }
2291
2292 rc = copyout(tmp, map_addr + scp->filesize, delta_size);
2293 kfree_data(tmp, delta_size);
2294
2295 if (rc) {
2296 DEBUG4K_ERROR("LOAD_FAILURE copyout 0x%llx 0x%llx\n", map_addr + scp->filesize, delta_size);
2297 return LOAD_FAILURE;
2298 }
2299 }
2300 #endif /* FIXME */
2301 }
2302
2303 /*
2304 * If the virtual size of the segment is greater
2305 * than the size from the file, we need to allocate
2306 * zero fill memory for the rest.
2307 */
2308 if ((vm_end - vm_start) > (file_end - file_start)) {
2309 delta_size = (vm_end - vm_start) - (file_end - file_start);
2310 } else {
2311 delta_size = 0;
2312 }
2313 if (delta_size > 0) {
2314 vm_map_offset_t tmp_start;
2315 vm_map_offset_t tmp_end;
2316
2317 if (os_add_overflow(vm_start, file_end - file_start, &tmp_start)) {
2318 DEBUG4K_ERROR("LOAD_NOSPACE tmp_start: 0x%llx + 0x%llx\n", (uint64_t)vm_start, (uint64_t)(file_end - file_start));
2319 return LOAD_NOSPACE;
2320 }
2321
2322 if (os_add_overflow(tmp_start, delta_size, &tmp_end)) {
2323 DEBUG4K_ERROR("LOAD_NOSPACE tmp_end: 0x%llx + 0x%llx\n", (uint64_t)tmp_start, (uint64_t)delta_size);
2324 return LOAD_NOSPACE;
2325 }
2326
2327 if (verbose) {
2328 MACHO_PRINTF(("++++++ load_segment: "
2329 "delta mapping vm [0x%llx:0x%llx]\n",
2330 (uint64_t) tmp_start,
2331 (uint64_t) tmp_end));
2332 }
2333 kr = map_segment(map,
2334 tmp_start,
2335 tmp_end,
2336 vmk_flags,
2337 MEMORY_OBJECT_CONTROL_NULL,
2338 0,
2339 delta_size,
2340 scp->initprot,
2341 scp->maxprot,
2342 result);
2343 if (kr != KERN_SUCCESS) {
2344 DEBUG4K_ERROR("LOAD_NOSPACE 0x%llx 0x%llx kr 0x%x\n", (unsigned long long)tmp_start, (uint64_t)delta_size, kr);
2345 return LOAD_NOSPACE;
2346 }
2347 }
2348
2349 if ((scp->fileoff == 0) && (scp->filesize != 0)) {
2350 result->mach_header = vm_offset;
2351 }
2352
2353 if (scp->flags & SG_PROTECTED_VERSION_1) {
2354 ret = unprotect_dsmos_segment(file_start,
2355 file_end - file_start,
2356 vp,
2357 pager_offset,
2358 map,
2359 vm_start,
2360 vm_end - vm_start);
2361 if (ret != LOAD_SUCCESS) {
2362 DEBUG4K_ERROR("unprotect 0x%llx 0x%llx ret %d \n", (uint64_t)vm_start, (uint64_t)vm_end, ret);
2363 return ret;
2364 }
2365 } else {
2366 ret = LOAD_SUCCESS;
2367 }
2368
2369 if (LOAD_SUCCESS == ret &&
2370 filetype == MH_DYLINKER &&
2371 result->all_image_info_addr == MACH_VM_MIN_ADDRESS) {
2372 note_all_image_info_section(scp,
2373 LC_SEGMENT_64 == lcp->cmd,
2374 single_section_size,
2375 ((const char *)lcp +
2376 segment_command_size),
2377 slide,
2378 result);
2379 }
2380
2381 if (result->entry_point != MACH_VM_MIN_ADDRESS) {
2382 if ((result->entry_point >= vm_offset) && (result->entry_point < (vm_offset + vm_size))) {
2383 if ((scp->initprot & (VM_PROT_READ | VM_PROT_EXECUTE)) == (VM_PROT_READ | VM_PROT_EXECUTE)) {
2384 result->validentry = 1;
2385 } else {
2386 /* right range but wrong protections, unset if previously validated */
2387 result->validentry = 0;
2388 }
2389 }
2390 }
2391
2392 if (ret != LOAD_SUCCESS && verbose) {
2393 DEBUG4K_ERROR("ret %d\n", ret);
2394 }
2395 return ret;
2396 }
2397
2398 static
2399 load_return_t
load_uuid(struct uuid_command * uulp,char * command_end,load_result_t * result)2400 load_uuid(
2401 struct uuid_command *uulp,
2402 char *command_end,
2403 load_result_t *result
2404 )
2405 {
2406 /*
2407 * We need to check the following for this command:
2408 * - The command size should be atleast the size of struct uuid_command
2409 * - The UUID part of the command should be completely within the mach-o header
2410 */
2411
2412 if ((uulp->cmdsize < sizeof(struct uuid_command)) ||
2413 (((char *)uulp + sizeof(struct uuid_command)) > command_end)) {
2414 return LOAD_BADMACHO;
2415 }
2416
2417 memcpy(&result->uuid[0], &uulp->uuid[0], sizeof(result->uuid));
2418 return LOAD_SUCCESS;
2419 }
2420
2421 static
2422 load_return_t
load_version(struct version_min_command * vmc,boolean_t * found_version_cmd,struct image_params * imgp __unused,load_result_t * result)2423 load_version(
2424 struct version_min_command *vmc,
2425 boolean_t *found_version_cmd,
2426 struct image_params *imgp __unused,
2427 load_result_t *result
2428 )
2429 {
2430 uint32_t platform = 0;
2431 uint32_t sdk;
2432 uint32_t min_sdk;
2433
2434 if (vmc->cmdsize < sizeof(*vmc)) {
2435 return LOAD_BADMACHO;
2436 }
2437 if (*found_version_cmd == TRUE) {
2438 return LOAD_BADMACHO;
2439 }
2440 *found_version_cmd = TRUE;
2441 sdk = vmc->sdk;
2442 min_sdk = vmc->version;
2443 switch (vmc->cmd) {
2444 case LC_VERSION_MIN_MACOSX:
2445 platform = PLATFORM_MACOS;
2446 break;
2447 #if __x86_64__ /* __x86_64__ */
2448 case LC_VERSION_MIN_IPHONEOS:
2449 platform = PLATFORM_IOSSIMULATOR;
2450 break;
2451 case LC_VERSION_MIN_WATCHOS:
2452 platform = PLATFORM_WATCHOSSIMULATOR;
2453 break;
2454 case LC_VERSION_MIN_TVOS:
2455 platform = PLATFORM_TVOSSIMULATOR;
2456 break;
2457 #else
2458 case LC_VERSION_MIN_IPHONEOS: {
2459 #if __arm64__
2460 if (vmc->sdk < (12 << 16)) {
2461 /* app built with a pre-iOS12 SDK: apply legacy footprint mitigation */
2462 result->legacy_footprint = TRUE;
2463 }
2464 #endif /* __arm64__ */
2465 platform = PLATFORM_IOS;
2466 break;
2467 }
2468 case LC_VERSION_MIN_WATCHOS:
2469 platform = PLATFORM_WATCHOS;
2470 break;
2471 case LC_VERSION_MIN_TVOS:
2472 platform = PLATFORM_TVOS;
2473 break;
2474 #endif /* __x86_64__ */
2475 /* All LC_VERSION_MIN_* load commands are legacy and we will not be adding any more */
2476 default:
2477 sdk = (uint32_t)-1;
2478 min_sdk = (uint32_t)-1;
2479 __builtin_unreachable();
2480 }
2481 result->ip_platform = platform;
2482 result->lr_min_sdk = min_sdk;
2483 result->lr_sdk = sdk;
2484 return LOAD_SUCCESS;
2485 }
2486
2487 static
2488 load_return_t
load_main(struct entry_point_command * epc,thread_t thread,int64_t slide,load_result_t * result)2489 load_main(
2490 struct entry_point_command *epc,
2491 thread_t thread,
2492 int64_t slide,
2493 load_result_t *result
2494 )
2495 {
2496 mach_vm_offset_t addr;
2497 kern_return_t ret;
2498
2499 if (epc->cmdsize < sizeof(*epc)) {
2500 return LOAD_BADMACHO;
2501 }
2502 if (result->thread_count != 0) {
2503 return LOAD_FAILURE;
2504 }
2505
2506 if (thread == THREAD_NULL) {
2507 return LOAD_SUCCESS;
2508 }
2509
2510 /*
2511 * LC_MAIN specifies stack size but not location.
2512 * Add guard page to allocation size (MAXSSIZ includes guard page).
2513 */
2514 if (epc->stacksize) {
2515 if (os_add_overflow(epc->stacksize, 4 * PAGE_SIZE, &result->user_stack_size)) {
2516 /*
2517 * We are going to immediately throw away this result, but we want
2518 * to make sure we aren't loading a dangerously close to
2519 * overflowing value, since this will have a guard page added to it
2520 * and be rounded to page boundaries
2521 */
2522 return LOAD_BADMACHO;
2523 }
2524 result->user_stack_size = epc->stacksize;
2525 if (os_add_overflow(epc->stacksize, PAGE_SIZE, &result->user_stack_alloc_size)) {
2526 return LOAD_BADMACHO;
2527 }
2528 result->custom_stack = TRUE;
2529 } else {
2530 result->user_stack_alloc_size = MAXSSIZ;
2531 }
2532
2533 /* use default location for stack */
2534 ret = thread_userstackdefault(&addr, result->is_64bit_addr);
2535 if (ret != KERN_SUCCESS) {
2536 return LOAD_FAILURE;
2537 }
2538
2539 /* The stack slides down from the default location */
2540 result->user_stack = (user_addr_t)mach_vm_trunc_page((user_addr_t)addr - slide);
2541
2542 if (result->using_lcmain || result->entry_point != MACH_VM_MIN_ADDRESS) {
2543 /* Already processed LC_MAIN or LC_UNIXTHREAD */
2544 return LOAD_FAILURE;
2545 }
2546
2547 /* kernel does *not* use entryoff from LC_MAIN. Dyld uses it. */
2548 result->needs_dynlinker = TRUE;
2549 result->using_lcmain = TRUE;
2550
2551 ret = thread_state_initialize( thread );
2552 if (ret != KERN_SUCCESS) {
2553 return LOAD_FAILURE;
2554 }
2555
2556 result->unixproc = TRUE;
2557 result->thread_count++;
2558
2559 return LOAD_SUCCESS;
2560 }
2561
2562 static
2563 load_return_t
setup_driver_main(thread_t thread,int64_t slide,load_result_t * result)2564 setup_driver_main(
2565 thread_t thread,
2566 int64_t slide,
2567 load_result_t *result
2568 )
2569 {
2570 mach_vm_offset_t addr;
2571 kern_return_t ret;
2572
2573 /* Driver binaries have no LC_MAIN, use defaults */
2574
2575 if (thread == THREAD_NULL) {
2576 return LOAD_SUCCESS;
2577 }
2578
2579 result->user_stack_alloc_size = MAXSSIZ;
2580
2581 /* use default location for stack */
2582 ret = thread_userstackdefault(&addr, result->is_64bit_addr);
2583 if (ret != KERN_SUCCESS) {
2584 return LOAD_FAILURE;
2585 }
2586
2587 /* The stack slides down from the default location */
2588 result->user_stack = (user_addr_t)addr;
2589 result->user_stack -= slide;
2590
2591 if (result->using_lcmain || result->entry_point != MACH_VM_MIN_ADDRESS) {
2592 /* Already processed LC_MAIN or LC_UNIXTHREAD */
2593 return LOAD_FAILURE;
2594 }
2595
2596 result->needs_dynlinker = TRUE;
2597
2598 ret = thread_state_initialize( thread );
2599 if (ret != KERN_SUCCESS) {
2600 return LOAD_FAILURE;
2601 }
2602
2603 result->unixproc = TRUE;
2604 result->thread_count++;
2605
2606 return LOAD_SUCCESS;
2607 }
2608
2609 static
2610 load_return_t
load_unixthread(struct thread_command * tcp,thread_t thread,int64_t slide,boolean_t is_x86_64_compat_binary,load_result_t * result)2611 load_unixthread(
2612 struct thread_command *tcp,
2613 thread_t thread,
2614 int64_t slide,
2615 boolean_t is_x86_64_compat_binary,
2616 load_result_t *result
2617 )
2618 {
2619 load_return_t ret;
2620 int customstack = 0;
2621 mach_vm_offset_t addr;
2622 if (tcp->cmdsize < sizeof(*tcp)) {
2623 return LOAD_BADMACHO;
2624 }
2625 if (result->thread_count != 0) {
2626 return LOAD_FAILURE;
2627 }
2628
2629 if (thread == THREAD_NULL) {
2630 return LOAD_SUCCESS;
2631 }
2632
2633 ret = load_threadstack(thread,
2634 (uint32_t *)(((vm_offset_t)tcp) +
2635 sizeof(struct thread_command)),
2636 tcp->cmdsize - sizeof(struct thread_command),
2637 &addr, &customstack, is_x86_64_compat_binary, result);
2638 if (ret != LOAD_SUCCESS) {
2639 return ret;
2640 }
2641
2642 /* LC_UNIXTHREAD optionally specifies stack size and location */
2643
2644 if (customstack) {
2645 result->custom_stack = TRUE;
2646 } else {
2647 result->user_stack_alloc_size = MAXSSIZ;
2648 }
2649
2650 /* The stack slides down from the default location */
2651 result->user_stack = (user_addr_t)mach_vm_trunc_page((user_addr_t)addr - slide);
2652
2653 {
2654 ret = load_threadentry(thread,
2655 (uint32_t *)(((vm_offset_t)tcp) +
2656 sizeof(struct thread_command)),
2657 tcp->cmdsize - sizeof(struct thread_command),
2658 &addr);
2659 if (ret != LOAD_SUCCESS) {
2660 return ret;
2661 }
2662
2663 if (result->using_lcmain || result->entry_point != MACH_VM_MIN_ADDRESS) {
2664 /* Already processed LC_MAIN or LC_UNIXTHREAD */
2665 return LOAD_FAILURE;
2666 }
2667
2668 result->entry_point = (user_addr_t)addr;
2669 result->entry_point += slide;
2670
2671 ret = load_threadstate(thread,
2672 (uint32_t *)(((vm_offset_t)tcp) + sizeof(struct thread_command)),
2673 tcp->cmdsize - sizeof(struct thread_command),
2674 result);
2675 if (ret != LOAD_SUCCESS) {
2676 return ret;
2677 }
2678 }
2679
2680 result->unixproc = TRUE;
2681 result->thread_count++;
2682
2683 return LOAD_SUCCESS;
2684 }
2685
2686 static
2687 load_return_t
load_threadstate(thread_t thread,uint32_t * ts,uint32_t total_size,load_result_t * result)2688 load_threadstate(
2689 thread_t thread,
2690 uint32_t *ts,
2691 uint32_t total_size,
2692 load_result_t *result
2693 )
2694 {
2695 uint32_t size;
2696 int flavor;
2697 uint32_t thread_size;
2698 uint32_t *local_ts = NULL;
2699 uint32_t local_ts_size = 0;
2700 int ret;
2701
2702 (void)thread;
2703
2704 if (total_size > 0) {
2705 local_ts_size = total_size;
2706 local_ts = (uint32_t *)kalloc_data(local_ts_size, Z_WAITOK);
2707 if (local_ts == NULL) {
2708 return LOAD_FAILURE;
2709 }
2710 memcpy(local_ts, ts, local_ts_size);
2711 ts = local_ts;
2712 }
2713
2714 /*
2715 * Validate the new thread state; iterate through the state flavors in
2716 * the Mach-O file.
2717 * XXX: we should validate the machine state here, to avoid failing at
2718 * activation time where we can't bail out cleanly.
2719 */
2720 while (total_size > 0) {
2721 if (total_size < 2 * sizeof(uint32_t)) {
2722 return LOAD_BADMACHO;
2723 }
2724
2725 flavor = *ts++;
2726 size = *ts++;
2727
2728 if (os_add_and_mul_overflow(size, 2, sizeof(uint32_t), &thread_size) ||
2729 os_sub_overflow(total_size, thread_size, &total_size)) {
2730 ret = LOAD_BADMACHO;
2731 goto bad;
2732 }
2733
2734 ts += size; /* ts is a (uint32_t *) */
2735 }
2736
2737 result->threadstate = local_ts;
2738 result->threadstate_sz = local_ts_size;
2739 return LOAD_SUCCESS;
2740
2741 bad:
2742 if (local_ts) {
2743 kfree_data(local_ts, local_ts_size);
2744 }
2745 return ret;
2746 }
2747
2748
2749 static
2750 load_return_t
load_threadstack(thread_t thread,uint32_t * ts,uint32_t total_size,mach_vm_offset_t * user_stack,int * customstack,__unused boolean_t is_x86_64_compat_binary,load_result_t * result)2751 load_threadstack(
2752 thread_t thread,
2753 uint32_t *ts,
2754 uint32_t total_size,
2755 mach_vm_offset_t *user_stack,
2756 int *customstack,
2757 __unused boolean_t is_x86_64_compat_binary,
2758 load_result_t *result
2759 )
2760 {
2761 kern_return_t ret;
2762 uint32_t size;
2763 int flavor;
2764 uint32_t stack_size;
2765
2766 if (total_size == 0) {
2767 return LOAD_BADMACHO;
2768 }
2769
2770 while (total_size > 0) {
2771 if (total_size < 2 * sizeof(uint32_t)) {
2772 return LOAD_BADMACHO;
2773 }
2774
2775 flavor = *ts++;
2776 size = *ts++;
2777 if (UINT32_MAX - 2 < size ||
2778 UINT32_MAX / sizeof(uint32_t) < size + 2) {
2779 return LOAD_BADMACHO;
2780 }
2781 stack_size = (size + 2) * sizeof(uint32_t);
2782 if (stack_size > total_size) {
2783 return LOAD_BADMACHO;
2784 }
2785 total_size -= stack_size;
2786
2787 /*
2788 * Third argument is a kernel space pointer; it gets cast
2789 * to the appropriate type in thread_userstack() based on
2790 * the value of flavor.
2791 */
2792 {
2793 ret = thread_userstack(thread, flavor, (thread_state_t)ts, size, user_stack, customstack, result->is_64bit_data);
2794 if (ret != KERN_SUCCESS) {
2795 return LOAD_FAILURE;
2796 }
2797 }
2798
2799 ts += size; /* ts is a (uint32_t *) */
2800 }
2801 return LOAD_SUCCESS;
2802 }
2803
2804 static
2805 load_return_t
load_threadentry(thread_t thread,uint32_t * ts,uint32_t total_size,mach_vm_offset_t * entry_point)2806 load_threadentry(
2807 thread_t thread,
2808 uint32_t *ts,
2809 uint32_t total_size,
2810 mach_vm_offset_t *entry_point
2811 )
2812 {
2813 kern_return_t ret;
2814 uint32_t size;
2815 int flavor;
2816 uint32_t entry_size;
2817
2818 /*
2819 * Set the thread state.
2820 */
2821 *entry_point = MACH_VM_MIN_ADDRESS;
2822 while (total_size > 0) {
2823 if (total_size < 2 * sizeof(uint32_t)) {
2824 return LOAD_BADMACHO;
2825 }
2826
2827 flavor = *ts++;
2828 size = *ts++;
2829 if (UINT32_MAX - 2 < size ||
2830 UINT32_MAX / sizeof(uint32_t) < size + 2) {
2831 return LOAD_BADMACHO;
2832 }
2833 entry_size = (size + 2) * sizeof(uint32_t);
2834 if (entry_size > total_size) {
2835 return LOAD_BADMACHO;
2836 }
2837 total_size -= entry_size;
2838 /*
2839 * Third argument is a kernel space pointer; it gets cast
2840 * to the appropriate type in thread_entrypoint() based on
2841 * the value of flavor.
2842 */
2843 ret = thread_entrypoint(thread, flavor, (thread_state_t)ts, size, entry_point);
2844 if (ret != KERN_SUCCESS) {
2845 return LOAD_FAILURE;
2846 }
2847 ts += size; /* ts is a (uint32_t *) */
2848 }
2849 return LOAD_SUCCESS;
2850 }
2851
2852 struct macho_data {
2853 struct nameidata __nid;
2854 union macho_vnode_header {
2855 struct mach_header mach_header;
2856 struct fat_header fat_header;
2857 char __pad[512];
2858 } __header;
2859 };
2860
2861 #define DEFAULT_DYLD_PATH "/usr/lib/dyld"
2862
2863 #if (DEVELOPMENT || DEBUG)
2864 extern char dyld_alt_path[];
2865 extern int use_alt_dyld;
2866
2867 extern char dyld_suffix[];
2868 extern int use_dyld_suffix;
2869
2870 typedef struct _dyld_suffix_map_entry {
2871 const char *suffix;
2872 const char *path;
2873 } dyld_suffix_map_entry_t;
2874
2875 static const dyld_suffix_map_entry_t _dyld_suffix_map[] = {
2876 [0] = {
2877 .suffix = "",
2878 .path = DEFAULT_DYLD_PATH,
2879 }, {
2880 .suffix = "release",
2881 .path = DEFAULT_DYLD_PATH,
2882 }, {
2883 .suffix = "bringup",
2884 .path = "/usr/appleinternal/lib/dyld.bringup",
2885 },
2886 };
2887 #endif
2888
2889 static load_return_t
load_dylinker(struct dylinker_command * lcp,cpu_type_t cputype,vm_map_t map,thread_t thread,int depth,int64_t slide,load_result_t * result,struct image_params * imgp)2890 load_dylinker(
2891 struct dylinker_command *lcp,
2892 cpu_type_t cputype,
2893 vm_map_t map,
2894 thread_t thread,
2895 int depth,
2896 int64_t slide,
2897 load_result_t *result,
2898 struct image_params *imgp
2899 )
2900 {
2901 const char *name;
2902 struct vnode *vp = NULLVP; /* set by get_macho_vnode() */
2903 struct mach_header *header;
2904 off_t file_offset = 0; /* set by get_macho_vnode() */
2905 off_t macho_size = 0; /* set by get_macho_vnode() */
2906 load_result_t *myresult;
2907 kern_return_t ret;
2908 struct macho_data *macho_data;
2909 struct {
2910 struct mach_header __header;
2911 load_result_t __myresult;
2912 struct macho_data __macho_data;
2913 } *dyld_data;
2914
2915 if (lcp->cmdsize < sizeof(*lcp) || lcp->name.offset >= lcp->cmdsize) {
2916 return LOAD_BADMACHO;
2917 }
2918
2919 name = (const char *)lcp + lcp->name.offset;
2920
2921 /* Check for a proper null terminated string. */
2922 size_t maxsz = lcp->cmdsize - lcp->name.offset;
2923 size_t namelen = strnlen(name, maxsz);
2924 if (namelen >= maxsz) {
2925 return LOAD_BADMACHO;
2926 }
2927
2928 #if (DEVELOPMENT || DEBUG)
2929
2930 /*
2931 * rdar://23680808
2932 * If an alternate dyld has been specified via boot args, check
2933 * to see if PROC_UUID_ALT_DYLD_POLICY has been set on this
2934 * executable and redirect the kernel to load that linker.
2935 */
2936
2937 if (use_alt_dyld) {
2938 int policy_error;
2939 uint32_t policy_flags = 0;
2940 int32_t policy_gencount = 0;
2941
2942 policy_error = proc_uuid_policy_lookup(result->uuid, &policy_flags, &policy_gencount);
2943 if (policy_error == 0) {
2944 if (policy_flags & PROC_UUID_ALT_DYLD_POLICY) {
2945 name = dyld_alt_path;
2946 }
2947 }
2948 } else if (use_dyld_suffix) {
2949 size_t i = 0;
2950
2951 #define countof(x) (sizeof(x) / sizeof(x[0]))
2952 for (i = 0; i < countof(_dyld_suffix_map); i++) {
2953 const dyld_suffix_map_entry_t *entry = &_dyld_suffix_map[i];
2954
2955 if (strcmp(entry->suffix, dyld_suffix) == 0) {
2956 name = entry->path;
2957 break;
2958 }
2959 }
2960 }
2961 #endif
2962
2963 #if !(DEVELOPMENT || DEBUG)
2964 if (0 != strcmp(name, DEFAULT_DYLD_PATH)) {
2965 return LOAD_BADMACHO;
2966 }
2967 #endif
2968
2969 /* Allocate wad-of-data from heap to reduce excessively deep stacks */
2970
2971 dyld_data = kalloc_type(typeof(*dyld_data), Z_WAITOK);
2972 header = &dyld_data->__header;
2973 myresult = &dyld_data->__myresult;
2974 macho_data = &dyld_data->__macho_data;
2975
2976 {
2977 cputype = (cputype & CPU_ARCH_MASK) | (cpu_type() & ~CPU_ARCH_MASK);
2978 }
2979
2980 ret = get_macho_vnode(name, cputype, header,
2981 &file_offset, &macho_size, macho_data, &vp, imgp);
2982 if (ret) {
2983 goto novp_out;
2984 }
2985
2986 *myresult = load_result_null;
2987 myresult->is_64bit_addr = result->is_64bit_addr;
2988 myresult->is_64bit_data = result->is_64bit_data;
2989
2990 ret = parse_machfile(vp, map, thread, header, file_offset,
2991 macho_size, depth, slide, 0, myresult, result, imgp);
2992
2993 if (ret == LOAD_SUCCESS) {
2994 if (result->threadstate) {
2995 /* don't use the app's threadstate if we have a dyld */
2996 kfree_data(result->threadstate, result->threadstate_sz);
2997 }
2998 result->threadstate = myresult->threadstate;
2999 result->threadstate_sz = myresult->threadstate_sz;
3000
3001 result->dynlinker = TRUE;
3002 result->entry_point = myresult->entry_point;
3003 result->validentry = myresult->validentry;
3004 result->all_image_info_addr = myresult->all_image_info_addr;
3005 result->all_image_info_size = myresult->all_image_info_size;
3006 if (!myresult->platform_binary) {
3007 result->csflags &= ~CS_NO_UNTRUSTED_HELPERS;
3008 }
3009
3010 #if CONFIG_ROSETTA
3011 if (imgp->ip_flags & IMGPF_ROSETTA) {
3012 extern const struct fileops vnops;
3013 // Save the file descriptor and mach header address for dyld. These will
3014 // be passed on the stack for the Rosetta runtime's use.
3015 struct fileproc *fp;
3016 int dyld_fd;
3017 proc_t p = vfs_context_proc(imgp->ip_vfs_context);
3018 int error = falloc_exec(p, imgp->ip_vfs_context, &fp, &dyld_fd);
3019 if (error == 0) {
3020 error = VNOP_OPEN(vp, FREAD, imgp->ip_vfs_context);
3021 if (error == 0) {
3022 fp->fp_glob->fg_flag = FREAD;
3023 fp->fp_glob->fg_ops = &vnops;
3024 fp_set_data(fp, vp);
3025
3026 proc_fdlock(p);
3027 procfdtbl_releasefd(p, dyld_fd, NULL);
3028 fp_drop(p, dyld_fd, fp, 1);
3029 proc_fdunlock(p);
3030
3031 vnode_ref(vp);
3032
3033 result->dynlinker_fd = dyld_fd;
3034 result->dynlinker_fp = fp;
3035 result->dynlinker_mach_header = myresult->mach_header;
3036 result->dynlinker_max_vm_addr = myresult->max_vm_addr;
3037 result->dynlinker_ro_vm_start = myresult->ro_vm_start;
3038 result->dynlinker_ro_vm_end = myresult->ro_vm_end;
3039 } else {
3040 fp_free(p, dyld_fd, fp);
3041 ret = LOAD_IOERROR;
3042 }
3043 } else {
3044 ret = LOAD_IOERROR;
3045 }
3046 }
3047 #endif
3048 }
3049
3050 struct vnode_attr *va;
3051 va = kalloc_type(struct vnode_attr, Z_WAITOK | Z_ZERO);
3052 VATTR_INIT(va);
3053 VATTR_WANTED(va, va_fsid64);
3054 VATTR_WANTED(va, va_fsid);
3055 VATTR_WANTED(va, va_fileid);
3056 int error = vnode_getattr(vp, va, imgp->ip_vfs_context);
3057 if (error == 0) {
3058 imgp->ip_dyld_fsid = vnode_get_va_fsid(va);
3059 imgp->ip_dyld_fsobjid = va->va_fileid;
3060 }
3061
3062 vnode_put(vp);
3063 kfree_type(struct vnode_attr, va);
3064 novp_out:
3065 kfree_type(typeof(*dyld_data), dyld_data);
3066 return ret;
3067 }
3068
3069 #if CONFIG_ROSETTA
3070 static const char* rosetta_runtime_path = "/usr/libexec/rosetta/runtime";
3071
3072 #if (DEVELOPMENT || DEBUG)
3073 static const char* rosetta_runtime_path_alt_x86 = "/usr/local/libexec/rosetta/runtime_internal";
3074 static const char* rosetta_runtime_path_alt_arm = "/usr/local/libexec/rosetta/runtime_arm_internal";
3075 #endif
3076
3077 static load_return_t
load_rosetta(vm_map_t map,thread_t thread,load_result_t * result,struct image_params * imgp)3078 load_rosetta(
3079 vm_map_t map,
3080 thread_t thread,
3081 load_result_t *result,
3082 struct image_params *imgp)
3083 {
3084 struct vnode *vp = NULLVP; /* set by get_macho_vnode() */
3085 struct mach_header *header;
3086 off_t file_offset = 0; /* set by get_macho_vnode() */
3087 off_t macho_size = 0; /* set by get_macho_vnode() */
3088 load_result_t *myresult;
3089 kern_return_t ret;
3090 struct macho_data *macho_data;
3091 const char *rosetta_file_path;
3092 struct {
3093 struct mach_header __header;
3094 load_result_t __myresult;
3095 struct macho_data __macho_data;
3096 } *rosetta_data;
3097 mach_vm_address_t rosetta_load_addr;
3098 mach_vm_size_t rosetta_size;
3099 mach_vm_address_t shared_cache_base = SHARED_REGION_BASE_ARM64;
3100 int64_t slide = 0;
3101
3102 /* Allocate wad-of-data from heap to reduce excessively deep stacks */
3103 rosetta_data = kalloc_type(typeof(*rosetta_data), Z_WAITOK | Z_NOFAIL);
3104 header = &rosetta_data->__header;
3105 myresult = &rosetta_data->__myresult;
3106 macho_data = &rosetta_data->__macho_data;
3107
3108 rosetta_file_path = rosetta_runtime_path;
3109
3110 #if (DEVELOPMENT || DEBUG)
3111 bool use_alt_rosetta = false;
3112 if (imgp->ip_flags & IMGPF_ALT_ROSETTA) {
3113 use_alt_rosetta = true;
3114 } else {
3115 int policy_error;
3116 uint32_t policy_flags = 0;
3117 int32_t policy_gencount = 0;
3118 policy_error = proc_uuid_policy_lookup(result->uuid, &policy_flags, &policy_gencount);
3119 if (policy_error == 0 && (policy_flags & PROC_UUID_ALT_ROSETTA_POLICY) != 0) {
3120 use_alt_rosetta = true;
3121 }
3122 }
3123
3124 if (use_alt_rosetta) {
3125 if (imgp->ip_origcputype == CPU_TYPE_X86_64) {
3126 rosetta_file_path = rosetta_runtime_path_alt_x86;
3127 } else if (imgp->ip_origcputype == CPU_TYPE_ARM64) {
3128 rosetta_file_path = rosetta_runtime_path_alt_arm;
3129 } else {
3130 ret = LOAD_BADARCH;
3131 goto novp_out;
3132 }
3133 }
3134 #endif
3135
3136 ret = get_macho_vnode(rosetta_file_path, CPU_TYPE_ARM64, header,
3137 &file_offset, &macho_size, macho_data, &vp, imgp);
3138 if (ret) {
3139 goto novp_out;
3140 }
3141
3142 *myresult = load_result_null;
3143 myresult->is_64bit_addr = TRUE;
3144 myresult->is_64bit_data = TRUE;
3145
3146 ret = parse_machfile(vp, NULL, NULL, header, file_offset, macho_size,
3147 2, 0, 0, myresult, NULL, imgp);
3148 if (ret != LOAD_SUCCESS) {
3149 goto out;
3150 }
3151
3152 if (!(imgp->ip_flags & IMGPF_DISABLE_ASLR)) {
3153 slide = random();
3154 slide = (slide % (vm_map_get_max_loader_aslr_slide_pages(map) - 1)) + 1;
3155 slide <<= vm_map_page_shift(map);
3156 }
3157
3158 if (imgp->ip_origcputype == CPU_TYPE_X86_64) {
3159 shared_cache_base = SHARED_REGION_BASE_X86_64;
3160 }
3161
3162 rosetta_size = round_page(myresult->max_vm_addr - myresult->min_vm_addr);
3163 rosetta_load_addr = shared_cache_base - rosetta_size - slide;
3164
3165 *myresult = load_result_null;
3166 myresult->is_64bit_addr = TRUE;
3167 myresult->is_64bit_data = TRUE;
3168 myresult->is_rosetta = TRUE;
3169
3170 ret = parse_machfile(vp, map, thread, header, file_offset, macho_size,
3171 2, rosetta_load_addr, 0, myresult, result, imgp);
3172 if (ret == LOAD_SUCCESS) {
3173 if (result) {
3174 if (result->threadstate) {
3175 /* don't use the app's/dyld's threadstate */
3176 kfree_data(result->threadstate, result->threadstate_sz);
3177 }
3178 assert(myresult->threadstate != NULL);
3179
3180 result->is_rosetta = TRUE;
3181
3182 result->threadstate = myresult->threadstate;
3183 result->threadstate_sz = myresult->threadstate_sz;
3184
3185 result->entry_point = myresult->entry_point;
3186 result->validentry = myresult->validentry;
3187 if (!myresult->platform_binary) {
3188 result->csflags &= ~CS_NO_UNTRUSTED_HELPERS;
3189 }
3190
3191 if ((header->cpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E) {
3192 imgp->ip_flags |= IMGPF_NOJOP;
3193 }
3194 }
3195 }
3196
3197 out:
3198 vnode_put(vp);
3199 novp_out:
3200 kfree_type(typeof(*rosetta_data), rosetta_data);
3201 return ret;
3202 }
3203 #endif
3204
3205 static void
set_signature_error(struct vnode * vp,struct image_params * imgp,const char * fatal_failure_desc,const size_t fatal_failure_desc_len)3206 set_signature_error(
3207 struct vnode* vp,
3208 struct image_params * imgp,
3209 const char* fatal_failure_desc,
3210 const size_t fatal_failure_desc_len)
3211 {
3212 char *vn_path = NULL;
3213 vm_size_t vn_pathlen = MAXPATHLEN;
3214 char const *path = NULL;
3215
3216 vn_path = zalloc(ZV_NAMEI);
3217 if (vn_getpath(vp, vn_path, (int*)&vn_pathlen) == 0) {
3218 path = vn_path;
3219 } else {
3220 path = "(get vnode path failed)";
3221 }
3222 os_reason_t reason = os_reason_create(OS_REASON_CODESIGNING,
3223 CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
3224
3225 if (reason == OS_REASON_NULL) {
3226 printf("load_code_signature: %s: failure to allocate exit reason for validation failure: %s\n",
3227 path, fatal_failure_desc);
3228 goto out;
3229 }
3230
3231 imgp->ip_cs_error = reason;
3232 reason->osr_flags = (OS_REASON_FLAG_GENERATE_CRASH_REPORT |
3233 OS_REASON_FLAG_CONSISTENT_FAILURE);
3234
3235 mach_vm_address_t data_addr = 0;
3236
3237 int reason_error = 0;
3238 int kcdata_error = 0;
3239
3240 if ((reason_error = os_reason_alloc_buffer_noblock(reason, kcdata_estimate_required_buffer_size
3241 (1, (uint32_t)fatal_failure_desc_len))) == 0 &&
3242 (kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
3243 EXIT_REASON_USER_DESC, (uint32_t)fatal_failure_desc_len,
3244 &data_addr)) == KERN_SUCCESS) {
3245 kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
3246 fatal_failure_desc, (uint32_t)fatal_failure_desc_len);
3247
3248 if (mc_error != KERN_SUCCESS) {
3249 printf("load_code_signature: %s: failed to copy reason string "
3250 "(kcdata_memcpy error: %d, length: %lu)\n",
3251 path, mc_error, fatal_failure_desc_len);
3252 }
3253 } else {
3254 printf("load_code_signature: %s: failed to allocate space for reason string "
3255 "(os_reason_alloc_buffer error: %d, kcdata error: %d, length: %lu)\n",
3256 path, reason_error, kcdata_error, fatal_failure_desc_len);
3257 }
3258 out:
3259 if (vn_path) {
3260 zfree(ZV_NAMEI, vn_path);
3261 }
3262 }
3263
3264 static load_return_t
load_code_signature(struct linkedit_data_command * lcp,struct vnode * vp,off_t macho_offset,off_t macho_size,cpu_type_t cputype,cpu_subtype_t cpusubtype,load_result_t * result,struct image_params * imgp)3265 load_code_signature(
3266 struct linkedit_data_command *lcp,
3267 struct vnode *vp,
3268 off_t macho_offset,
3269 off_t macho_size,
3270 cpu_type_t cputype,
3271 cpu_subtype_t cpusubtype,
3272 load_result_t *result,
3273 struct image_params *imgp)
3274 {
3275 int ret;
3276 kern_return_t kr;
3277 vm_offset_t addr;
3278 int resid;
3279 struct cs_blob *blob;
3280 int error;
3281 vm_size_t blob_size;
3282 uint32_t sum;
3283 boolean_t anyCPU;
3284
3285 addr = 0;
3286 blob = NULL;
3287
3288 cpusubtype &= ~CPU_SUBTYPE_MASK;
3289
3290 blob = ubc_cs_blob_get(vp, cputype, cpusubtype, macho_offset);
3291
3292 if (blob != NULL) {
3293 /* we already have a blob for this vnode and cpu(sub)type */
3294 anyCPU = blob->csb_cpu_type == -1;
3295 if ((blob->csb_cpu_type != cputype &&
3296 blob->csb_cpu_subtype != cpusubtype && !anyCPU) ||
3297 (blob->csb_base_offset != macho_offset) ||
3298 ((blob->csb_flags & CS_VALID) == 0)) {
3299 /* the blob has changed for this vnode: fail ! */
3300 ret = LOAD_BADMACHO;
3301 const char* fatal_failure_desc = "embedded signature doesn't match attached signature";
3302 const size_t fatal_failure_desc_len = strlen(fatal_failure_desc) + 1;
3303
3304 printf("load_code_signature: %s\n", fatal_failure_desc);
3305 set_signature_error(vp, imgp, fatal_failure_desc, fatal_failure_desc_len);
3306 goto out;
3307 }
3308
3309 /* It matches the blob we want here, let's verify the version */
3310 if (!anyCPU && ubc_cs_generation_check(vp) == 0) {
3311 /* No need to revalidate, we're good! */
3312 ret = LOAD_SUCCESS;
3313 goto out;
3314 }
3315
3316 /* That blob may be stale, let's revalidate. */
3317 error = ubc_cs_blob_revalidate(vp, blob, imgp, 0, result->ip_platform);
3318 if (error == 0) {
3319 /* Revalidation succeeded, we're good! */
3320 /* If we were revaliding a CS blob with any CPU arch we adjust it */
3321 if (anyCPU) {
3322 vnode_lock_spin(vp);
3323 struct cs_cpu_info cpu_info = {
3324 .csb_cpu_type = cputype,
3325 .csb_cpu_subtype = cpusubtype
3326 };
3327 zalloc_ro_update_field(ZONE_ID_CS_BLOB, blob, csb_cpu_info, &cpu_info);
3328 vnode_unlock(vp);
3329 }
3330 ret = LOAD_SUCCESS;
3331 goto out;
3332 }
3333
3334 if (error != EAGAIN) {
3335 printf("load_code_signature: revalidation failed: %d\n", error);
3336 ret = LOAD_FAILURE;
3337 goto out;
3338 }
3339
3340 assert(error == EAGAIN);
3341
3342 /*
3343 * Revalidation was not possible for this blob. We just continue as if there was no blob,
3344 * rereading the signature, and ubc_cs_blob_add will do the right thing.
3345 */
3346 blob = NULL;
3347 }
3348
3349 if (lcp->cmdsize != sizeof(struct linkedit_data_command)) {
3350 ret = LOAD_BADMACHO;
3351 goto out;
3352 }
3353
3354 sum = 0;
3355 if (os_add_overflow(lcp->dataoff, lcp->datasize, &sum) || sum > macho_size) {
3356 ret = LOAD_BADMACHO;
3357 goto out;
3358 }
3359
3360 blob_size = lcp->datasize;
3361 kr = ubc_cs_blob_allocate(&addr, &blob_size);
3362 if (kr != KERN_SUCCESS) {
3363 ret = LOAD_NOSPACE;
3364 goto out;
3365 }
3366
3367 resid = 0;
3368 error = vn_rdwr(UIO_READ,
3369 vp,
3370 (caddr_t) addr,
3371 lcp->datasize,
3372 macho_offset + lcp->dataoff,
3373 UIO_SYSSPACE,
3374 0,
3375 kauth_cred_get(),
3376 &resid,
3377 current_proc());
3378 if (error || resid != 0) {
3379 ret = LOAD_IOERROR;
3380 goto out;
3381 }
3382
3383 if (ubc_cs_blob_add(vp,
3384 result->ip_platform,
3385 cputype,
3386 cpusubtype,
3387 macho_offset,
3388 &addr,
3389 lcp->datasize,
3390 imgp,
3391 0,
3392 &blob,
3393 CS_BLOB_ADD_ALLOW_MAIN_BINARY)) {
3394 if (addr) {
3395 ubc_cs_blob_deallocate(addr, blob_size);
3396 addr = 0;
3397 }
3398 ret = LOAD_FAILURE;
3399 goto out;
3400 } else {
3401 /* ubc_cs_blob_add() has consumed "addr" */
3402 addr = 0;
3403 }
3404
3405 #if CHECK_CS_VALIDATION_BITMAP
3406 ubc_cs_validation_bitmap_allocate( vp );
3407 #endif
3408
3409 ret = LOAD_SUCCESS;
3410 out:
3411 if (ret == LOAD_SUCCESS) {
3412 if (blob == NULL) {
3413 panic("success, but no blob!");
3414 }
3415
3416 result->csflags |= blob->csb_flags;
3417 result->platform_binary = blob->csb_platform_binary;
3418 result->cs_end_offset = blob->csb_end_offset;
3419 }
3420 if (addr != 0) {
3421 ubc_cs_blob_deallocate(addr, blob_size);
3422 addr = 0;
3423 }
3424
3425 return ret;
3426 }
3427
3428
3429 #if CONFIG_CODE_DECRYPTION
3430
3431 static load_return_t
set_code_unprotect(struct encryption_info_command * eip,caddr_t addr,vm_map_t map,int64_t slide,struct vnode * vp,off_t macho_offset,cpu_type_t cputype,cpu_subtype_t cpusubtype)3432 set_code_unprotect(
3433 struct encryption_info_command *eip,
3434 caddr_t addr,
3435 vm_map_t map,
3436 int64_t slide,
3437 struct vnode *vp,
3438 off_t macho_offset,
3439 cpu_type_t cputype,
3440 cpu_subtype_t cpusubtype)
3441 {
3442 int error, len;
3443 pager_crypt_info_t crypt_info;
3444 const char * cryptname = 0;
3445 char *vpath;
3446
3447 size_t offset;
3448 struct segment_command_64 *seg64;
3449 struct segment_command *seg32;
3450 vm_map_offset_t map_offset, map_size;
3451 vm_object_offset_t crypto_backing_offset;
3452 kern_return_t kr;
3453
3454 if (eip->cmdsize < sizeof(*eip)) {
3455 return LOAD_BADMACHO;
3456 }
3457
3458 switch (eip->cryptid) {
3459 case 0:
3460 /* not encrypted, just an empty load command */
3461 return LOAD_SUCCESS;
3462 case 1:
3463 cryptname = "com.apple.unfree";
3464 break;
3465 case 0x10:
3466 /* some random cryptid that you could manually put into
3467 * your binary if you want NULL */
3468 cryptname = "com.apple.null";
3469 break;
3470 default:
3471 return LOAD_BADMACHO;
3472 }
3473
3474 if (map == VM_MAP_NULL) {
3475 return LOAD_SUCCESS;
3476 }
3477 if (NULL == text_crypter_create) {
3478 return LOAD_FAILURE;
3479 }
3480
3481 vpath = zalloc(ZV_NAMEI);
3482
3483 len = MAXPATHLEN;
3484 error = vn_getpath(vp, vpath, &len);
3485 if (error) {
3486 zfree(ZV_NAMEI, vpath);
3487 return LOAD_FAILURE;
3488 }
3489
3490 if (eip->cryptsize == 0) {
3491 printf("%s:%d '%s': cryptoff 0x%llx cryptsize 0x%llx cryptid 0x%x ignored\n", __FUNCTION__, __LINE__, vpath, (uint64_t)eip->cryptoff, (uint64_t)eip->cryptsize, eip->cryptid);
3492 zfree(ZV_NAMEI, vpath);
3493 return LOAD_SUCCESS;
3494 }
3495
3496 /* set up decrypter first */
3497 crypt_file_data_t crypt_data = {
3498 .filename = vpath,
3499 .cputype = cputype,
3500 .cpusubtype = cpusubtype,
3501 .origin = CRYPT_ORIGIN_APP_LAUNCH,
3502 };
3503 kr = text_crypter_create(&crypt_info, cryptname, (void*)&crypt_data);
3504 #if VM_MAP_DEBUG_APPLE_PROTECT
3505 if (vm_map_debug_apple_protect) {
3506 struct proc *p;
3507 p = current_proc();
3508 printf("APPLE_PROTECT: %d[%s] map %p %s(%s) -> 0x%x\n",
3509 proc_getpid(p), p->p_comm, map, __FUNCTION__, vpath, kr);
3510 }
3511 #endif /* VM_MAP_DEBUG_APPLE_PROTECT */
3512 zfree(ZV_NAMEI, vpath);
3513
3514 if (kr) {
3515 printf("set_code_unprotect: unable to create decrypter %s, kr=%d\n",
3516 cryptname, kr);
3517 if (kr == kIOReturnNotPrivileged) {
3518 /* text encryption returned decryption failure */
3519 return LOAD_DECRYPTFAIL;
3520 } else {
3521 return LOAD_RESOURCE;
3522 }
3523 }
3524
3525 /* this is terrible, but we have to rescan the load commands to find the
3526 * virtual address of this encrypted stuff. This code is gonna look like
3527 * the dyld source one day... */
3528 struct mach_header *header = (struct mach_header *)addr;
3529 size_t mach_header_sz = sizeof(struct mach_header);
3530 if (header->magic == MH_MAGIC_64 ||
3531 header->magic == MH_CIGAM_64) {
3532 mach_header_sz = sizeof(struct mach_header_64);
3533 }
3534 offset = mach_header_sz;
3535 uint32_t ncmds = header->ncmds;
3536 while (ncmds--) {
3537 /*
3538 * Get a pointer to the command.
3539 */
3540 struct load_command *lcp = (struct load_command *)(addr + offset);
3541 offset += lcp->cmdsize;
3542
3543 switch (lcp->cmd) {
3544 case LC_SEGMENT_64:
3545 seg64 = (struct segment_command_64 *)lcp;
3546 if ((seg64->fileoff <= eip->cryptoff) &&
3547 (seg64->fileoff + seg64->filesize >=
3548 eip->cryptoff + eip->cryptsize)) {
3549 map_offset = (vm_map_offset_t)(seg64->vmaddr + eip->cryptoff - seg64->fileoff + slide);
3550 map_size = eip->cryptsize;
3551 crypto_backing_offset = macho_offset + eip->cryptoff;
3552 goto remap_now;
3553 }
3554 break;
3555 case LC_SEGMENT:
3556 seg32 = (struct segment_command *)lcp;
3557 if ((seg32->fileoff <= eip->cryptoff) &&
3558 (seg32->fileoff + seg32->filesize >=
3559 eip->cryptoff + eip->cryptsize)) {
3560 map_offset = (vm_map_offset_t)(seg32->vmaddr + eip->cryptoff - seg32->fileoff + slide);
3561 map_size = eip->cryptsize;
3562 crypto_backing_offset = macho_offset + eip->cryptoff;
3563 goto remap_now;
3564 }
3565 break;
3566 }
3567 }
3568
3569 /* if we get here, did not find anything */
3570 return LOAD_BADMACHO;
3571
3572 remap_now:
3573 /* now remap using the decrypter */
3574 MACHO_PRINTF(("+++ set_code_unprotect: vm[0x%llx:0x%llx]\n",
3575 (uint64_t) map_offset,
3576 (uint64_t) (map_offset + map_size)));
3577 kr = vm_map_apple_protected(map,
3578 map_offset,
3579 map_offset + map_size,
3580 crypto_backing_offset,
3581 &crypt_info,
3582 CRYPTID_APP_ENCRYPTION);
3583 if (kr) {
3584 printf("set_code_unprotect(): mapping failed with %x\n", kr);
3585 return LOAD_PROTECT;
3586 }
3587
3588 return LOAD_SUCCESS;
3589 }
3590
3591 #endif
3592
3593 /*
3594 * This routine exists to support the load_dylinker().
3595 *
3596 * This routine has its own, separate, understanding of the FAT file format,
3597 * which is terrifically unfortunate.
3598 */
3599 static
3600 load_return_t
get_macho_vnode(const char * path,cpu_type_t cputype,struct mach_header * mach_header,off_t * file_offset,off_t * macho_size,struct macho_data * data,struct vnode ** vpp,struct image_params * imgp)3601 get_macho_vnode(
3602 const char *path,
3603 cpu_type_t cputype,
3604 struct mach_header *mach_header,
3605 off_t *file_offset,
3606 off_t *macho_size,
3607 struct macho_data *data,
3608 struct vnode **vpp,
3609 struct image_params *imgp
3610 )
3611 {
3612 struct vnode *vp;
3613 vfs_context_t ctx = vfs_context_current();
3614 proc_t p = vfs_context_proc(ctx);
3615 kauth_cred_t kerncred;
3616 struct nameidata *ndp = &data->__nid;
3617 boolean_t is_fat;
3618 struct fat_arch fat_arch;
3619 int error;
3620 int resid;
3621 union macho_vnode_header *header = &data->__header;
3622 off_t fsize = (off_t)0;
3623
3624 /*
3625 * Capture the kernel credential for use in the actual read of the
3626 * file, since the user doing the execution may have execute rights
3627 * but not read rights, but to exec something, we have to either map
3628 * or read it into the new process address space, which requires
3629 * read rights. This is to deal with lack of common credential
3630 * serialization code which would treat NOCRED as "serialize 'root'".
3631 */
3632 kerncred = vfs_context_ucred(vfs_context_kernel());
3633
3634 /* init the namei data to point the file user's program name */
3635 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | LOCKLEAF, UIO_SYSSPACE, CAST_USER_ADDR_T(path), ctx);
3636
3637 if ((error = namei(ndp)) != 0) {
3638 if (error == ENOENT) {
3639 error = LOAD_ENOENT;
3640 } else {
3641 error = LOAD_FAILURE;
3642 }
3643 return error;
3644 }
3645 nameidone(ndp);
3646 vp = ndp->ni_vp;
3647
3648 /* check for regular file */
3649 if (vp->v_type != VREG) {
3650 error = LOAD_PROTECT;
3651 goto bad1;
3652 }
3653
3654 /* get size */
3655 if ((error = vnode_size(vp, &fsize, ctx)) != 0) {
3656 error = LOAD_FAILURE;
3657 goto bad1;
3658 }
3659
3660 /* Check mount point */
3661 if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
3662 error = LOAD_PROTECT;
3663 goto bad1;
3664 }
3665
3666 /* check access */
3667 if ((error = vnode_authorize(vp, NULL, KAUTH_VNODE_EXECUTE | KAUTH_VNODE_READ_DATA, ctx)) != 0) {
3668 error = LOAD_PROTECT;
3669 goto bad1;
3670 }
3671
3672 /* try to open it */
3673 if ((error = VNOP_OPEN(vp, FREAD, ctx)) != 0) {
3674 error = LOAD_PROTECT;
3675 goto bad1;
3676 }
3677
3678 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)header, sizeof(*header), 0,
3679 UIO_SYSSPACE, IO_NODELOCKED, kerncred, &resid, p)) != 0) {
3680 error = LOAD_IOERROR;
3681 goto bad2;
3682 }
3683
3684 if (resid) {
3685 error = LOAD_BADMACHO;
3686 goto bad2;
3687 }
3688
3689 if (header->mach_header.magic == MH_MAGIC ||
3690 header->mach_header.magic == MH_MAGIC_64) {
3691 is_fat = FALSE;
3692 } else if (OSSwapBigToHostInt32(header->fat_header.magic) == FAT_MAGIC) {
3693 is_fat = TRUE;
3694 } else {
3695 error = LOAD_BADMACHO;
3696 goto bad2;
3697 }
3698
3699 if (is_fat) {
3700 error = fatfile_validate_fatarches((vm_offset_t)(&header->fat_header),
3701 sizeof(*header), fsize);
3702 if (error != LOAD_SUCCESS) {
3703 goto bad2;
3704 }
3705
3706 /* Look up our architecture in the fat file. */
3707 error = fatfile_getbestarch_for_cputype(cputype, CPU_SUBTYPE_ANY,
3708 (vm_offset_t)(&header->fat_header), sizeof(*header), imgp, &fat_arch);
3709 if (error != LOAD_SUCCESS) {
3710 goto bad2;
3711 }
3712
3713 /* Read the Mach-O header out of it */
3714 error = vn_rdwr(UIO_READ, vp, (caddr_t)&header->mach_header,
3715 sizeof(header->mach_header), fat_arch.offset,
3716 UIO_SYSSPACE, IO_NODELOCKED, kerncred, &resid, p);
3717 if (error) {
3718 error = LOAD_IOERROR;
3719 goto bad2;
3720 }
3721
3722 if (resid) {
3723 error = LOAD_BADMACHO;
3724 goto bad2;
3725 }
3726
3727 /* Is this really a Mach-O? */
3728 if (header->mach_header.magic != MH_MAGIC &&
3729 header->mach_header.magic != MH_MAGIC_64) {
3730 error = LOAD_BADMACHO;
3731 goto bad2;
3732 }
3733
3734 *file_offset = fat_arch.offset;
3735 *macho_size = fat_arch.size;
3736 } else {
3737 /*
3738 * Force get_macho_vnode() to fail if the architecture bits
3739 * do not match the expected architecture bits. This in
3740 * turn causes load_dylinker() to fail for the same reason,
3741 * so it ensures the dynamic linker and the binary are in
3742 * lock-step. This is potentially bad, if we ever add to
3743 * the CPU_ARCH_* bits any bits that are desirable but not
3744 * required, since the dynamic linker might work, but we will
3745 * refuse to load it because of this check.
3746 */
3747 if ((cpu_type_t)header->mach_header.cputype != cputype) {
3748 error = LOAD_BADARCH;
3749 goto bad2;
3750 }
3751
3752 *file_offset = 0;
3753 *macho_size = fsize;
3754 }
3755
3756 *mach_header = header->mach_header;
3757 *vpp = vp;
3758
3759 ubc_setsize(vp, fsize);
3760 return error;
3761
3762 bad2:
3763 (void) VNOP_CLOSE(vp, FREAD, ctx);
3764 bad1:
3765 vnode_put(vp);
3766 return error;
3767 }
3768