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1 /*
2 * Copyright (c) 2000-2010 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/ubc_internal.h>
51 #include <sys/imgact.h>
52 #include <sys/codesign.h>
53
54 #include <mach/mach_types.h>
55 #include <mach/vm_map.h> /* vm_allocate() */
56 #include <mach/mach_vm.h> /* mach_vm_allocate() */
57 #include <mach/vm_statistics.h>
58 #include <mach/task.h>
59 #include <mach/thread_act.h>
60
61 #include <machine/vmparam.h>
62 #include <machine/exec.h>
63 #include <machine/pal_routines.h>
64
65 #include <kern/kern_types.h>
66 #include <kern/cpu_number.h>
67 #include <kern/mach_loader.h>
68 #include <kern/mach_fat.h>
69 #include <kern/kalloc.h>
70 #include <kern/task.h>
71 #include <kern/thread.h>
72 #include <kern/page_decrypt.h>
73
74 #include <mach-o/fat.h>
75 #include <mach-o/loader.h>
76
77 #include <vm/pmap.h>
78 #include <vm/vm_map.h>
79 #include <vm/vm_kern.h>
80 #include <vm/vm_pager.h>
81 #include <vm/vnode_pager.h>
82 #include <vm/vm_protos.h>
83 #include <IOKit/IOReturn.h> /* for kIOReturnNotPrivileged */
84
85 /*
86 * XXX vm/pmap.h should not treat these prototypes as MACH_KERNEL_PRIVATE
87 * when KERNEL is defined.
88 */
89 extern pmap_t pmap_create(ledger_t ledger, vm_map_size_t size,
90 boolean_t is_64bit);
91
92 /* XXX should have prototypes in a shared header file */
93 extern int get_map_nentries(vm_map_t);
94
95 extern kern_return_t memory_object_signed(memory_object_control_t control,
96 boolean_t is_signed);
97
98 /* An empty load_result_t */
99 static load_result_t load_result_null = {
100 .mach_header = MACH_VM_MIN_ADDRESS,
101 .entry_point = MACH_VM_MIN_ADDRESS,
102 .user_stack = MACH_VM_MIN_ADDRESS,
103 .user_stack_size = 0,
104 .all_image_info_addr = MACH_VM_MIN_ADDRESS,
105 .all_image_info_size = 0,
106 .thread_count = 0,
107 .unixproc = 0,
108 .dynlinker = 0,
109 .needs_dynlinker = 0,
110 .prog_allocated_stack = 0,
111 .prog_stack_size = 0,
112 .validentry = 0,
113 .csflags = 0,
114 .uuid = { 0 },
115 .min_vm_addr = MACH_VM_MAX_ADDRESS,
116 .max_vm_addr = MACH_VM_MIN_ADDRESS,
117 .cs_end_offset = 0
118 };
119
120 /*
121 * Prototypes of static functions.
122 */
123 static load_return_t
124 parse_machfile(
125 struct vnode *vp,
126 vm_map_t map,
127 thread_t thread,
128 struct mach_header *header,
129 off_t file_offset,
130 off_t macho_size,
131 int depth,
132 int64_t slide,
133 int64_t dyld_slide,
134 load_result_t *result
135 );
136
137 static load_return_t
138 load_segment(
139 struct load_command *lcp,
140 uint32_t filetype,
141 void *control,
142 off_t pager_offset,
143 off_t macho_size,
144 struct vnode *vp,
145 vm_map_t map,
146 int64_t slide,
147 load_result_t *result
148 );
149
150 static load_return_t
151 load_uuid(
152 struct uuid_command *uulp,
153 char *command_end,
154 load_result_t *result
155 );
156
157 static load_return_t
158 load_code_signature(
159 struct linkedit_data_command *lcp,
160 struct vnode *vp,
161 off_t macho_offset,
162 off_t macho_size,
163 cpu_type_t cputype,
164 load_result_t *result);
165
166 #if CONFIG_CODE_DECRYPTION
167 static load_return_t
168 set_code_unprotect(
169 struct encryption_info_command *lcp,
170 caddr_t addr,
171 vm_map_t map,
172 int64_t slide,
173 struct vnode *vp,
174 cpu_type_t cputype,
175 cpu_subtype_t cpusubtype);
176 #endif
177
178 static
179 load_return_t
180 load_main(
181 struct entry_point_command *epc,
182 thread_t thread,
183 int64_t slide,
184 load_result_t *result
185 );
186
187 static load_return_t
188 load_unixthread(
189 struct thread_command *tcp,
190 thread_t thread,
191 int64_t slide,
192 load_result_t *result
193 );
194
195 static load_return_t
196 load_threadstate(
197 thread_t thread,
198 uint32_t *ts,
199 uint32_t total_size
200 );
201
202 static load_return_t
203 load_threadstack(
204 thread_t thread,
205 uint32_t *ts,
206 uint32_t total_size,
207 mach_vm_offset_t *user_stack,
208 int *customstack
209 );
210
211 static load_return_t
212 load_threadentry(
213 thread_t thread,
214 uint32_t *ts,
215 uint32_t total_size,
216 mach_vm_offset_t *entry_point
217 );
218
219 static load_return_t
220 load_dylinker(
221 struct dylinker_command *lcp,
222 integer_t archbits,
223 vm_map_t map,
224 thread_t thread,
225 int depth,
226 int64_t slide,
227 load_result_t *result
228 );
229
230 struct macho_data;
231
232 static load_return_t
233 get_macho_vnode(
234 char *path,
235 integer_t archbits,
236 struct mach_header *mach_header,
237 off_t *file_offset,
238 off_t *macho_size,
239 struct macho_data *macho_data,
240 struct vnode **vpp
241 );
242
243 static inline void
244 widen_segment_command(const struct segment_command *scp32,
245 struct segment_command_64 *scp)
246 {
247 scp->cmd = scp32->cmd;
248 scp->cmdsize = scp32->cmdsize;
249 bcopy(scp32->segname, scp->segname, sizeof(scp->segname));
250 scp->vmaddr = scp32->vmaddr;
251 scp->vmsize = scp32->vmsize;
252 scp->fileoff = scp32->fileoff;
253 scp->filesize = scp32->filesize;
254 scp->maxprot = scp32->maxprot;
255 scp->initprot = scp32->initprot;
256 scp->nsects = scp32->nsects;
257 scp->flags = scp32->flags;
258 }
259
260 static void
261 note_all_image_info_section(const struct segment_command_64 *scp,
262 boolean_t is64, size_t section_size, const void *sections,
263 int64_t slide, load_result_t *result)
264 {
265 const union {
266 struct section s32;
267 struct section_64 s64;
268 } *sectionp;
269 unsigned int i;
270
271 if (strncmp(scp->segname, "__DATA", sizeof(scp->segname)) != 0)
272 return;
273 for (i = 0; i < scp->nsects; ++i) {
274 sectionp = (const void *)
275 ((const char *)sections + section_size * i);
276 if (0 == strncmp(sectionp->s64.sectname, "__all_image_info",
277 sizeof(sectionp->s64.sectname))) {
278 result->all_image_info_addr =
279 is64 ? sectionp->s64.addr : sectionp->s32.addr;
280 result->all_image_info_addr += slide;
281 result->all_image_info_size =
282 is64 ? sectionp->s64.size : sectionp->s32.size;
283 return;
284 }
285 }
286 }
287
288 load_return_t
289 load_machfile(
290 struct image_params *imgp,
291 struct mach_header *header,
292 thread_t thread,
293 vm_map_t new_map,
294 load_result_t *result
295 )
296 {
297 struct vnode *vp = imgp->ip_vp;
298 off_t file_offset = imgp->ip_arch_offset;
299 off_t macho_size = imgp->ip_arch_size;
300 off_t file_size = imgp->ip_vattr->va_data_size;
301
302 pmap_t pmap = 0; /* protected by create_map */
303 vm_map_t map;
304 vm_map_t old_map;
305 task_t old_task = TASK_NULL; /* protected by create_map */
306 load_result_t myresult;
307 load_return_t lret;
308 boolean_t create_map = FALSE;
309 boolean_t enforce_hard_pagezero = TRUE;
310 int spawn = (imgp->ip_flags & IMGPF_SPAWN);
311 task_t task = current_task();
312 proc_t p = current_proc();
313 mach_vm_offset_t aslr_offset = 0;
314 mach_vm_offset_t dyld_aslr_offset = 0;
315 kern_return_t kret;
316
317 if (macho_size > file_size) {
318 return(LOAD_BADMACHO);
319 }
320
321 if (new_map == VM_MAP_NULL) {
322 create_map = TRUE;
323 old_task = current_task();
324 }
325
326 /*
327 * If we are spawning, we have created backing objects for the process
328 * already, which include non-lazily creating the task map. So we
329 * are going to switch out the task map with one appropriate for the
330 * bitness of the image being loaded.
331 */
332 if (spawn) {
333 create_map = TRUE;
334 old_task = get_threadtask(thread);
335 }
336
337 if (create_map) {
338 task_t ledger_task;
339 if (imgp->ip_new_thread) {
340 ledger_task = get_threadtask(imgp->ip_new_thread);
341 } else {
342 ledger_task = task;
343 }
344 pmap = pmap_create(get_task_ledger(ledger_task),
345 (vm_map_size_t) 0,
346 (imgp->ip_flags & IMGPF_IS_64BIT));
347 pal_switch_pmap(thread, pmap, imgp->ip_flags & IMGPF_IS_64BIT);
348 map = vm_map_create(pmap,
349 0,
350 vm_compute_max_offset((imgp->ip_flags & IMGPF_IS_64BIT)),
351 TRUE);
352 } else
353 map = new_map;
354
355
356 #ifndef CONFIG_ENFORCE_SIGNED_CODE
357 /* This turns off faulting for executable pages, which allows
358 * to circumvent Code Signing Enforcement. The per process
359 * flag (CS_ENFORCEMENT) is not set yet, but we can use the
360 * global flag.
361 */
362 if ( !cs_enforcement(NULL) && (header->flags & MH_ALLOW_STACK_EXECUTION) )
363 vm_map_disable_NX(map);
364 #endif
365
366 /* Forcibly disallow execution from data pages on even if the arch
367 * normally permits it. */
368 if ((header->flags & MH_NO_HEAP_EXECUTION) && !(imgp->ip_flags & IMGPF_ALLOW_DATA_EXEC))
369 vm_map_disallow_data_exec(map);
370
371 /*
372 * Compute a random offset for ASLR, and an independent random offset for dyld.
373 */
374 if (!(imgp->ip_flags & IMGPF_DISABLE_ASLR)) {
375 uint64_t max_slide_pages;
376
377 max_slide_pages = vm_map_get_max_aslr_slide_pages(map);
378
379 aslr_offset = random();
380 aslr_offset %= max_slide_pages;
381 aslr_offset <<= vm_map_page_shift(map);
382
383 dyld_aslr_offset = random();
384 dyld_aslr_offset %= max_slide_pages;
385 dyld_aslr_offset <<= vm_map_page_shift(map);
386 }
387
388 if (!result)
389 result = &myresult;
390
391 *result = load_result_null;
392
393 lret = parse_machfile(vp, map, thread, header, file_offset, macho_size,
394 0, (int64_t)aslr_offset, (int64_t)dyld_aslr_offset, result);
395
396 if (lret != LOAD_SUCCESS) {
397 if (create_map) {
398 vm_map_deallocate(map); /* will lose pmap reference too */
399 }
400 return(lret);
401 }
402
403 #if __x86_64__
404 /*
405 * On x86, for compatibility, don't enforce the hard page-zero restriction for 32-bit binaries.
406 */
407 if ((imgp->ip_flags & IMGPF_IS_64BIT) == 0) {
408 enforce_hard_pagezero = FALSE;
409 }
410 #endif
411 /*
412 * Check to see if the page zero is enforced by the map->min_offset.
413 */
414 if (enforce_hard_pagezero && (vm_map_has_hard_pagezero(map, 0x1000) == FALSE)) {
415 if (create_map) {
416 vm_map_deallocate(map); /* will lose pmap reference too */
417 }
418 printf("Cannot enforce a hard page-zero for %s\n", imgp->ip_strings);
419 return (LOAD_BADMACHO);
420 }
421
422 /*
423 * Commit to new map.
424 *
425 * Swap the new map for the old, which consumes our new map
426 * reference but each leaves us responsible for the old_map reference.
427 * That lets us get off the pmap associated with it, and
428 * then we can release it.
429 */
430
431 if (create_map) {
432 /*
433 * If this is an exec, then we are going to destroy the old
434 * task, and it's correct to halt it; if it's spawn, the
435 * task is not yet running, and it makes no sense.
436 */
437 if (!spawn) {
438 /*
439 * Mark the task as halting and start the other
440 * threads towards terminating themselves. Then
441 * make sure any threads waiting for a process
442 * transition get informed that we are committed to
443 * this transition, and then finally complete the
444 * task halting (wait for threads and then cleanup
445 * task resources).
446 *
447 * NOTE: task_start_halt() makes sure that no new
448 * threads are created in the task during the transition.
449 * We need to mark the workqueue as exiting before we
450 * wait for threads to terminate (at the end of which
451 * we no longer have a prohibition on thread creation).
452 *
453 * Finally, clean up any lingering workqueue data structures
454 * that may have been left behind by the workqueue threads
455 * as they exited (and then clean up the work queue itself).
456 */
457 kret = task_start_halt(task);
458 if (kret != KERN_SUCCESS) {
459 vm_map_deallocate(map); /* will lose pmap reference too */
460 return (LOAD_FAILURE);
461 }
462 proc_transcommit(p, 0);
463 workqueue_mark_exiting(p);
464 task_complete_halt(task);
465 workqueue_exit(p);
466 }
467 old_map = swap_task_map(old_task, thread, map, !spawn);
468 vm_map_deallocate(old_map);
469 }
470 return(LOAD_SUCCESS);
471 }
472
473 /*
474 * The file size of a mach-o file is limited to 32 bits; this is because
475 * this is the limit on the kalloc() of enough bytes for a mach_header and
476 * the contents of its sizeofcmds, which is currently constrained to 32
477 * bits in the file format itself. We read into the kernel buffer the
478 * commands section, and then parse it in order to parse the mach-o file
479 * format load_command segment(s). We are only interested in a subset of
480 * the total set of possible commands. If "map"==VM_MAP_NULL or
481 * "thread"==THREAD_NULL, do not make permament VM modifications,
482 * just preflight the parse.
483 */
484 static
485 load_return_t
486 parse_machfile(
487 struct vnode *vp,
488 vm_map_t map,
489 thread_t thread,
490 struct mach_header *header,
491 off_t file_offset,
492 off_t macho_size,
493 int depth,
494 int64_t aslr_offset,
495 int64_t dyld_aslr_offset,
496 load_result_t *result
497 )
498 {
499 uint32_t ncmds;
500 struct load_command *lcp;
501 struct dylinker_command *dlp = 0;
502 integer_t dlarchbits = 0;
503 void * control;
504 load_return_t ret = LOAD_SUCCESS;
505 caddr_t addr;
506 void * kl_addr;
507 vm_size_t size,kl_size;
508 size_t offset;
509 size_t oldoffset; /* for overflow check */
510 int pass;
511 proc_t p = current_proc(); /* XXXX */
512 int error;
513 int resid=0;
514 size_t mach_header_sz = sizeof(struct mach_header);
515 boolean_t abi64;
516 boolean_t got_code_signatures = FALSE;
517 int64_t slide = 0;
518
519 if (header->magic == MH_MAGIC_64 ||
520 header->magic == MH_CIGAM_64) {
521 mach_header_sz = sizeof(struct mach_header_64);
522 }
523
524 /*
525 * Break infinite recursion
526 */
527 if (depth > 6) {
528 return(LOAD_FAILURE);
529 }
530
531 depth++;
532
533 /*
534 * Check to see if right machine type.
535 */
536 if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != (cpu_type() & ~CPU_ARCH_MASK)) ||
537 !grade_binary(header->cputype,
538 header->cpusubtype & ~CPU_SUBTYPE_MASK))
539 return(LOAD_BADARCH);
540
541 abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64);
542
543 switch (header->filetype) {
544
545 case MH_OBJECT:
546 case MH_EXECUTE:
547 case MH_PRELOAD:
548 if (depth != 1) {
549 return (LOAD_FAILURE);
550 }
551 break;
552
553 case MH_FVMLIB:
554 case MH_DYLIB:
555 if (depth == 1) {
556 return (LOAD_FAILURE);
557 }
558 break;
559
560 case MH_DYLINKER:
561 if (depth != 2) {
562 return (LOAD_FAILURE);
563 }
564 break;
565
566 default:
567 return (LOAD_FAILURE);
568 }
569
570 /*
571 * Get the pager for the file.
572 */
573 control = ubc_getobject(vp, UBC_FLAGS_NONE);
574
575 /*
576 * Map portion that must be accessible directly into
577 * kernel's map.
578 */
579 if ((off_t)(mach_header_sz + header->sizeofcmds) > macho_size)
580 return(LOAD_BADMACHO);
581
582 /*
583 * Round size of Mach-O commands up to page boundry.
584 */
585 size = round_page(mach_header_sz + header->sizeofcmds);
586 if (size <= 0)
587 return(LOAD_BADMACHO);
588
589 /*
590 * Map the load commands into kernel memory.
591 */
592 addr = 0;
593 kl_size = size;
594 kl_addr = kalloc(size);
595 addr = (caddr_t)kl_addr;
596 if (addr == NULL)
597 return(LOAD_NOSPACE);
598
599 error = vn_rdwr(UIO_READ, vp, addr, size, file_offset,
600 UIO_SYSSPACE, 0, kauth_cred_get(), &resid, p);
601 if (error) {
602 if (kl_addr )
603 kfree(kl_addr, kl_size);
604 return(LOAD_IOERROR);
605 }
606
607 /*
608 * For PIE and dyld, slide everything by the ASLR offset.
609 */
610 if ((header->flags & MH_PIE) || (header->filetype == MH_DYLINKER)) {
611 slide = aslr_offset;
612 }
613
614 /*
615 * Scan through the commands, processing each one as necessary.
616 * We parse in three passes through the headers:
617 * 1: thread state, uuid, code signature
618 * 2: segments
619 * 3: dyld, encryption, check entry point
620 */
621
622 for (pass = 1; pass <= 3; pass++) {
623
624 /*
625 * Check that the entry point is contained in an executable segments
626 */
627 if ((pass == 3) && (result->validentry == 0)) {
628 thread_state_initialize(thread);
629 ret = LOAD_FAILURE;
630 break;
631 }
632
633 /*
634 * Loop through each of the load_commands indicated by the
635 * Mach-O header; if an absurd value is provided, we just
636 * run off the end of the reserved section by incrementing
637 * the offset too far, so we are implicitly fail-safe.
638 */
639 offset = mach_header_sz;
640 ncmds = header->ncmds;
641
642 while (ncmds--) {
643 /*
644 * Get a pointer to the command.
645 */
646 lcp = (struct load_command *)(addr + offset);
647 oldoffset = offset;
648 offset += lcp->cmdsize;
649
650 /*
651 * Perform prevalidation of the struct load_command
652 * before we attempt to use its contents. Invalid
653 * values are ones which result in an overflow, or
654 * which can not possibly be valid commands, or which
655 * straddle or exist past the reserved section at the
656 * start of the image.
657 */
658 if (oldoffset > offset ||
659 lcp->cmdsize < sizeof(struct load_command) ||
660 offset > header->sizeofcmds + mach_header_sz) {
661 ret = LOAD_BADMACHO;
662 break;
663 }
664
665 /*
666 * Act on struct load_command's for which kernel
667 * intervention is required.
668 */
669 switch(lcp->cmd) {
670 case LC_SEGMENT:
671 if (pass != 2)
672 break;
673
674 if (abi64) {
675 /*
676 * Having an LC_SEGMENT command for the
677 * wrong ABI is invalid <rdar://problem/11021230>
678 */
679 ret = LOAD_BADMACHO;
680 break;
681 }
682
683 ret = load_segment(lcp,
684 header->filetype,
685 control,
686 file_offset,
687 macho_size,
688 vp,
689 map,
690 slide,
691 result);
692 break;
693 case LC_SEGMENT_64:
694 if (pass != 2)
695 break;
696
697 if (!abi64) {
698 /*
699 * Having an LC_SEGMENT_64 command for the
700 * wrong ABI is invalid <rdar://problem/11021230>
701 */
702 ret = LOAD_BADMACHO;
703 break;
704 }
705
706 ret = load_segment(lcp,
707 header->filetype,
708 control,
709 file_offset,
710 macho_size,
711 vp,
712 map,
713 slide,
714 result);
715 break;
716 case LC_UNIXTHREAD:
717 if (pass != 1)
718 break;
719 ret = load_unixthread(
720 (struct thread_command *) lcp,
721 thread,
722 slide,
723 result);
724 break;
725 case LC_MAIN:
726 if (pass != 1)
727 break;
728 if (depth != 1)
729 break;
730 ret = load_main(
731 (struct entry_point_command *) lcp,
732 thread,
733 slide,
734 result);
735 break;
736 case LC_LOAD_DYLINKER:
737 if (pass != 3)
738 break;
739 if ((depth == 1) && (dlp == 0)) {
740 dlp = (struct dylinker_command *)lcp;
741 dlarchbits = (header->cputype & CPU_ARCH_MASK);
742 } else {
743 ret = LOAD_FAILURE;
744 }
745 break;
746 case LC_UUID:
747 if (pass == 1 && depth == 1) {
748 ret = load_uuid((struct uuid_command *) lcp,
749 (char *)addr + mach_header_sz + header->sizeofcmds,
750 result);
751 }
752 break;
753 case LC_CODE_SIGNATURE:
754 /* CODE SIGNING */
755 if (pass != 1)
756 break;
757 /* pager -> uip ->
758 load signatures & store in uip
759 set VM object "signed_pages"
760 */
761 ret = load_code_signature(
762 (struct linkedit_data_command *) lcp,
763 vp,
764 file_offset,
765 macho_size,
766 header->cputype,
767 result);
768 if (ret != LOAD_SUCCESS) {
769 printf("proc %d: load code signature error %d "
770 "for file \"%s\"\n",
771 p->p_pid, ret, vp->v_name);
772 ret = LOAD_SUCCESS; /* ignore error */
773 } else {
774 got_code_signatures = TRUE;
775 }
776
777 if (got_code_signatures) {
778 boolean_t valid = FALSE, tainted = TRUE;
779 struct cs_blob *blobs;
780 vm_size_t off = 0;
781
782
783 if (cs_debug > 10)
784 printf("validating initial pages of %s\n", vp->v_name);
785 blobs = ubc_get_cs_blobs(vp);
786
787 while (off < size && ret == LOAD_SUCCESS) {
788 valid = cs_validate_page(blobs,
789 NULL,
790 file_offset + off,
791 addr + off,
792 &tainted);
793 if (!valid || tainted) {
794 if (cs_debug)
795 printf("CODE SIGNING: %s[%d]: invalid initial page at offset %lld validated:%d tainted:%d csflags:0x%x\n",
796 vp->v_name, p->p_pid, (long long)(file_offset + off), valid, tainted, result->csflags);
797 if (cs_enforcement(NULL) ||
798 (result->csflags & (CS_HARD|CS_KILL|CS_ENFORCEMENT))) {
799 ret = LOAD_FAILURE;
800 }
801 result->csflags &= ~CS_VALID;
802 }
803 off += PAGE_SIZE;
804 }
805 }
806
807 break;
808 #if CONFIG_CODE_DECRYPTION
809 case LC_ENCRYPTION_INFO:
810 case LC_ENCRYPTION_INFO_64:
811 if (pass != 3)
812 break;
813 ret = set_code_unprotect(
814 (struct encryption_info_command *) lcp,
815 addr, map, slide, vp,
816 header->cputype, header->cpusubtype);
817 if (ret != LOAD_SUCCESS) {
818 printf("proc %d: set_code_unprotect() error %d "
819 "for file \"%s\"\n",
820 p->p_pid, ret, vp->v_name);
821 /*
822 * Don't let the app run if it's
823 * encrypted but we failed to set up the
824 * decrypter. If the keys are missing it will
825 * return LOAD_DECRYPTFAIL.
826 */
827 if (ret == LOAD_DECRYPTFAIL) {
828 /* failed to load due to missing FP keys */
829 proc_lock(p);
830 p->p_lflag |= P_LTERM_DECRYPTFAIL;
831 proc_unlock(p);
832 }
833 psignal(p, SIGKILL);
834 }
835 break;
836 #endif
837 default:
838 /* Other commands are ignored by the kernel */
839 ret = LOAD_SUCCESS;
840 break;
841 }
842 if (ret != LOAD_SUCCESS)
843 break;
844 }
845 if (ret != LOAD_SUCCESS)
846 break;
847 }
848
849 if (ret == LOAD_SUCCESS) {
850 if (! got_code_signatures) {
851 struct cs_blob *blob;
852 /* no embedded signatures: look for detached ones */
853 blob = ubc_cs_blob_get(vp, -1, file_offset);
854 if (blob != NULL) {
855 unsigned int cs_flag_data = blob->csb_flags;
856 if(0 != ubc_cs_generation_check(vp)) {
857 if (0 != ubc_cs_blob_revalidate(vp, blob)) {
858 /* clear out the flag data if revalidation fails */
859 cs_flag_data = 0;
860 result->csflags &= ~CS_VALID;
861 }
862 }
863 /* get flags to be applied to the process */
864 result->csflags |= cs_flag_data;
865 }
866 }
867
868 /* Make sure if we need dyld, we got it */
869 if (result->needs_dynlinker && !dlp) {
870 ret = LOAD_FAILURE;
871 }
872
873 if ((ret == LOAD_SUCCESS) && (dlp != 0)) {
874 /*
875 * load the dylinker, and slide it by the independent DYLD ASLR
876 * offset regardless of the PIE-ness of the main binary.
877 */
878 ret = load_dylinker(dlp, dlarchbits, map, thread, depth,
879 dyld_aslr_offset, result);
880 }
881
882 if((ret == LOAD_SUCCESS) && (depth == 1)) {
883 if (result->thread_count == 0) {
884 ret = LOAD_FAILURE;
885 }
886 }
887 }
888
889 if (kl_addr )
890 kfree(kl_addr, kl_size);
891
892 return(ret);
893 }
894
895 #if CONFIG_CODE_DECRYPTION
896
897 #define APPLE_UNPROTECTED_HEADER_SIZE (3 * PAGE_SIZE_64)
898
899 static load_return_t
900 unprotect_dsmos_segment(
901 uint64_t file_off,
902 uint64_t file_size,
903 struct vnode *vp,
904 off_t macho_offset,
905 vm_map_t map,
906 vm_map_offset_t map_addr,
907 vm_map_size_t map_size)
908 {
909 kern_return_t kr;
910
911 /*
912 * The first APPLE_UNPROTECTED_HEADER_SIZE bytes (from offset 0 of
913 * this part of a Universal binary) are not protected...
914 * The rest needs to be "transformed".
915 */
916 if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE &&
917 file_off + file_size <= APPLE_UNPROTECTED_HEADER_SIZE) {
918 /* it's all unprotected, nothing to do... */
919 kr = KERN_SUCCESS;
920 } else {
921 if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE) {
922 /*
923 * We start mapping in the unprotected area.
924 * Skip the unprotected part...
925 */
926 vm_map_offset_t delta;
927
928 delta = APPLE_UNPROTECTED_HEADER_SIZE;
929 delta -= file_off;
930 map_addr += delta;
931 map_size -= delta;
932 }
933 /* ... transform the rest of the mapping. */
934 struct pager_crypt_info crypt_info;
935 crypt_info.page_decrypt = dsmos_page_transform;
936 crypt_info.crypt_ops = NULL;
937 crypt_info.crypt_end = NULL;
938 #pragma unused(vp, macho_offset)
939 crypt_info.crypt_ops = (void *)0x2e69cf40;
940 kr = vm_map_apple_protected(map,
941 map_addr,
942 map_addr + map_size,
943 &crypt_info);
944 }
945
946 if (kr != KERN_SUCCESS) {
947 return LOAD_FAILURE;
948 }
949 return LOAD_SUCCESS;
950 }
951 #else /* CONFIG_CODE_DECRYPTION */
952 static load_return_t
953 unprotect_dsmos_segment(
954 __unused uint64_t file_off,
955 __unused uint64_t file_size,
956 __unused struct vnode *vp,
957 __unused off_t macho_offset,
958 __unused vm_map_t map,
959 __unused vm_map_offset_t map_addr,
960 __unused vm_map_size_t map_size)
961 {
962 return LOAD_SUCCESS;
963 }
964 #endif /* CONFIG_CODE_DECRYPTION */
965
966 static
967 load_return_t
968 load_segment(
969 struct load_command *lcp,
970 uint32_t filetype,
971 void * control,
972 off_t pager_offset,
973 off_t macho_size,
974 struct vnode *vp,
975 vm_map_t map,
976 int64_t slide,
977 load_result_t *result
978 )
979 {
980 struct segment_command_64 segment_command, *scp;
981 kern_return_t ret;
982 vm_map_offset_t map_addr, map_offset;
983 vm_map_size_t map_size, seg_size, delta_size;
984 vm_prot_t initprot;
985 vm_prot_t maxprot;
986 size_t segment_command_size, total_section_size,
987 single_section_size;
988
989 if (LC_SEGMENT_64 == lcp->cmd) {
990 segment_command_size = sizeof(struct segment_command_64);
991 single_section_size = sizeof(struct section_64);
992 } else {
993 segment_command_size = sizeof(struct segment_command);
994 single_section_size = sizeof(struct section);
995 }
996 if (lcp->cmdsize < segment_command_size)
997 return (LOAD_BADMACHO);
998 total_section_size = lcp->cmdsize - segment_command_size;
999
1000 if (LC_SEGMENT_64 == lcp->cmd)
1001 scp = (struct segment_command_64 *)lcp;
1002 else {
1003 scp = &segment_command;
1004 widen_segment_command((struct segment_command *)lcp, scp);
1005 }
1006
1007 /*
1008 * Make sure what we get from the file is really ours (as specified
1009 * by macho_size).
1010 */
1011 if (scp->fileoff + scp->filesize < scp->fileoff ||
1012 scp->fileoff + scp->filesize > (uint64_t)macho_size)
1013 return (LOAD_BADMACHO);
1014 /*
1015 * Ensure that the number of sections specified would fit
1016 * within the load command size.
1017 */
1018 if (total_section_size / single_section_size < scp->nsects)
1019 return (LOAD_BADMACHO);
1020 /*
1021 * Make sure the segment is page-aligned in the file.
1022 */
1023 if ((scp->fileoff & PAGE_MASK_64) != 0)
1024 return (LOAD_BADMACHO);
1025
1026 /*
1027 * If we have a code signature attached for this slice
1028 * require that the segments are within the signed part
1029 * of the file.
1030 */
1031 if (result->cs_end_offset &&
1032 result->cs_end_offset < (off_t)scp->fileoff &&
1033 result->cs_end_offset - scp->fileoff < scp->filesize)
1034 {
1035 if (cs_debug)
1036 printf("section outside code signature\n");
1037 return LOAD_BADMACHO;
1038 }
1039
1040 /*
1041 * Round sizes to page size.
1042 */
1043 seg_size = round_page_64(scp->vmsize);
1044 map_size = round_page_64(scp->filesize);
1045 map_addr = trunc_page_64(scp->vmaddr); /* JVXXX note that in XNU TOT this is round instead of trunc for 64 bits */
1046
1047 seg_size = vm_map_round_page(seg_size, vm_map_page_mask(map));
1048 map_size = vm_map_round_page(map_size, vm_map_page_mask(map));
1049
1050 if (seg_size == 0)
1051 return (KERN_SUCCESS);
1052 if (map_addr == 0 &&
1053 map_size == 0 &&
1054 seg_size != 0 &&
1055 (scp->initprot & VM_PROT_ALL) == VM_PROT_NONE &&
1056 (scp->maxprot & VM_PROT_ALL) == VM_PROT_NONE) {
1057 /*
1058 * For PIE, extend page zero rather than moving it. Extending
1059 * page zero keeps early allocations from falling predictably
1060 * between the end of page zero and the beginning of the first
1061 * slid segment.
1062 */
1063 seg_size += slide;
1064 slide = 0;
1065
1066 /*
1067 * This is a "page zero" segment: it starts at address 0,
1068 * is not mapped from the binary file and is not accessible.
1069 * User-space should never be able to access that memory, so
1070 * make it completely off limits by raising the VM map's
1071 * minimum offset.
1072 */
1073 ret = vm_map_raise_min_offset(map, seg_size);
1074 if (ret != KERN_SUCCESS) {
1075 return (LOAD_FAILURE);
1076 }
1077 return (LOAD_SUCCESS);
1078 }
1079
1080 /* If a non-zero slide was specified by the caller, apply now */
1081 map_addr += slide;
1082
1083 if (map_addr < result->min_vm_addr)
1084 result->min_vm_addr = map_addr;
1085 if (map_addr+seg_size > result->max_vm_addr)
1086 result->max_vm_addr = map_addr+seg_size;
1087
1088 if (map == VM_MAP_NULL)
1089 return (LOAD_SUCCESS);
1090
1091 map_offset = pager_offset + scp->fileoff; /* limited to 32 bits */
1092
1093 if (map_size > 0) {
1094 initprot = (scp->initprot) & VM_PROT_ALL;
1095 maxprot = (scp->maxprot) & VM_PROT_ALL;
1096 /*
1097 * Map a copy of the file into the address space.
1098 */
1099 ret = vm_map_enter_mem_object_control(map,
1100 &map_addr, map_size, (mach_vm_offset_t)0,
1101 VM_FLAGS_FIXED, control, map_offset, TRUE,
1102 initprot, maxprot,
1103 VM_INHERIT_DEFAULT);
1104 if (ret != KERN_SUCCESS) {
1105 return (LOAD_NOSPACE);
1106 }
1107
1108 /*
1109 * If the file didn't end on a page boundary,
1110 * we need to zero the leftover.
1111 */
1112 delta_size = map_size - scp->filesize;
1113 #if FIXME
1114 if (delta_size > 0) {
1115 mach_vm_offset_t tmp;
1116
1117 ret = mach_vm_allocate(kernel_map, &tmp, delta_size, VM_FLAGS_ANYWHERE);
1118 if (ret != KERN_SUCCESS)
1119 return(LOAD_RESOURCE);
1120
1121 if (copyout(tmp, map_addr + scp->filesize,
1122 delta_size)) {
1123 (void) mach_vm_deallocate(
1124 kernel_map, tmp, delta_size);
1125 return (LOAD_FAILURE);
1126 }
1127
1128 (void) mach_vm_deallocate(kernel_map, tmp, delta_size);
1129 }
1130 #endif /* FIXME */
1131 }
1132
1133 /*
1134 * If the virtual size of the segment is greater
1135 * than the size from the file, we need to allocate
1136 * zero fill memory for the rest.
1137 */
1138 delta_size = seg_size - map_size;
1139 if (delta_size > 0) {
1140 mach_vm_offset_t tmp = map_addr + map_size;
1141
1142 ret = mach_vm_map(map, &tmp, delta_size, 0, VM_FLAGS_FIXED,
1143 NULL, 0, FALSE,
1144 scp->initprot, scp->maxprot,
1145 VM_INHERIT_DEFAULT);
1146 if (ret != KERN_SUCCESS)
1147 return(LOAD_NOSPACE);
1148 }
1149
1150 if ( (scp->fileoff == 0) && (scp->filesize != 0) )
1151 result->mach_header = map_addr;
1152
1153 if (scp->flags & SG_PROTECTED_VERSION_1) {
1154 ret = unprotect_dsmos_segment(scp->fileoff,
1155 scp->filesize,
1156 vp,
1157 pager_offset,
1158 map,
1159 map_addr,
1160 map_size);
1161 } else {
1162 ret = LOAD_SUCCESS;
1163 }
1164 if (LOAD_SUCCESS == ret && filetype == MH_DYLINKER &&
1165 result->all_image_info_addr == MACH_VM_MIN_ADDRESS)
1166 note_all_image_info_section(scp,
1167 LC_SEGMENT_64 == lcp->cmd, single_section_size,
1168 (const char *)lcp + segment_command_size, slide, result);
1169
1170 if ((result->entry_point >= map_addr) && (result->entry_point < (map_addr + map_size)))
1171 result->validentry = 1;
1172
1173 return ret;
1174 }
1175
1176 static
1177 load_return_t
1178 load_uuid(
1179 struct uuid_command *uulp,
1180 char *command_end,
1181 load_result_t *result
1182 )
1183 {
1184 /*
1185 * We need to check the following for this command:
1186 * - The command size should be atleast the size of struct uuid_command
1187 * - The UUID part of the command should be completely within the mach-o header
1188 */
1189
1190 if ((uulp->cmdsize < sizeof(struct uuid_command)) ||
1191 (((char *)uulp + sizeof(struct uuid_command)) > command_end)) {
1192 return (LOAD_BADMACHO);
1193 }
1194
1195 memcpy(&result->uuid[0], &uulp->uuid[0], sizeof(result->uuid));
1196 return (LOAD_SUCCESS);
1197 }
1198
1199 static
1200 load_return_t
1201 load_main(
1202 struct entry_point_command *epc,
1203 thread_t thread,
1204 int64_t slide,
1205 load_result_t *result
1206 )
1207 {
1208 mach_vm_offset_t addr;
1209 kern_return_t ret;
1210
1211 if (epc->cmdsize < sizeof(*epc))
1212 return (LOAD_BADMACHO);
1213 if (result->thread_count != 0) {
1214 printf("load_main: already have a thread!");
1215 return (LOAD_FAILURE);
1216 }
1217
1218 if (thread == THREAD_NULL)
1219 return (LOAD_SUCCESS);
1220
1221 /* LC_MAIN specifies stack size but not location */
1222 if (epc->stacksize) {
1223 result->prog_stack_size = 1;
1224 result->user_stack_size = epc->stacksize;
1225 } else {
1226 result->prog_stack_size = 0;
1227 result->user_stack_size = MAXSSIZ;
1228 }
1229 result->prog_allocated_stack = 0;
1230
1231 /* use default location for stack */
1232 ret = thread_userstackdefault(thread, &addr);
1233 if (ret != KERN_SUCCESS)
1234 return(LOAD_FAILURE);
1235
1236 /* The stack slides down from the default location */
1237 result->user_stack = addr;
1238 result->user_stack -= slide;
1239
1240 /* kernel does *not* use entryoff from LC_MAIN. Dyld uses it. */
1241 result->needs_dynlinker = TRUE;
1242 result->validentry = TRUE;
1243
1244 ret = thread_state_initialize( thread );
1245 if (ret != KERN_SUCCESS) {
1246 return(LOAD_FAILURE);
1247 }
1248
1249 result->unixproc = TRUE;
1250 result->thread_count++;
1251
1252 return(LOAD_SUCCESS);
1253 }
1254
1255
1256 static
1257 load_return_t
1258 load_unixthread(
1259 struct thread_command *tcp,
1260 thread_t thread,
1261 int64_t slide,
1262 load_result_t *result
1263 )
1264 {
1265 load_return_t ret;
1266 int customstack =0;
1267 mach_vm_offset_t addr;
1268
1269 if (tcp->cmdsize < sizeof(*tcp))
1270 return (LOAD_BADMACHO);
1271 if (result->thread_count != 0) {
1272 printf("load_unixthread: already have a thread!");
1273 return (LOAD_FAILURE);
1274 }
1275
1276 if (thread == THREAD_NULL)
1277 return (LOAD_SUCCESS);
1278
1279 ret = load_threadstack(thread,
1280 (uint32_t *)(((vm_offset_t)tcp) +
1281 sizeof(struct thread_command)),
1282 tcp->cmdsize - sizeof(struct thread_command),
1283 &addr,
1284 &customstack);
1285 if (ret != LOAD_SUCCESS)
1286 return(ret);
1287
1288 /* LC_UNIXTHREAD optionally specifies stack size and location */
1289
1290 if (customstack) {
1291 result->prog_stack_size = 0; /* unknown */
1292 result->prog_allocated_stack = 1;
1293 } else {
1294 result->prog_allocated_stack = 0;
1295 result->prog_stack_size = 0;
1296 result->user_stack_size = MAXSSIZ;
1297 }
1298
1299 /* The stack slides down from the default location */
1300 result->user_stack = addr;
1301 result->user_stack -= slide;
1302
1303 ret = load_threadentry(thread,
1304 (uint32_t *)(((vm_offset_t)tcp) +
1305 sizeof(struct thread_command)),
1306 tcp->cmdsize - sizeof(struct thread_command),
1307 &addr);
1308 if (ret != LOAD_SUCCESS)
1309 return(ret);
1310
1311 result->entry_point = addr;
1312 result->entry_point += slide;
1313
1314 ret = load_threadstate(thread,
1315 (uint32_t *)(((vm_offset_t)tcp) +
1316 sizeof(struct thread_command)),
1317 tcp->cmdsize - sizeof(struct thread_command));
1318 if (ret != LOAD_SUCCESS)
1319 return (ret);
1320
1321 result->unixproc = TRUE;
1322 result->thread_count++;
1323
1324 return(LOAD_SUCCESS);
1325 }
1326
1327 static
1328 load_return_t
1329 load_threadstate(
1330 thread_t thread,
1331 uint32_t *ts,
1332 uint32_t total_size
1333 )
1334 {
1335 kern_return_t ret;
1336 uint32_t size;
1337 int flavor;
1338 uint32_t thread_size;
1339 uint32_t *local_ts;
1340 uint32_t local_ts_size;
1341
1342 local_ts = NULL;
1343 local_ts_size = 0;
1344
1345 ret = thread_state_initialize( thread );
1346 if (ret != KERN_SUCCESS) {
1347 ret = LOAD_FAILURE;
1348 goto done;
1349 }
1350
1351 if (total_size > 0) {
1352 local_ts_size = total_size;
1353 local_ts = kalloc(local_ts_size);
1354 if (local_ts == NULL) {
1355 ret = LOAD_FAILURE;
1356 goto done;
1357 }
1358 memcpy(local_ts, ts, local_ts_size);
1359 ts = local_ts;
1360 }
1361
1362 /*
1363 * Set the new thread state; iterate through the state flavors in
1364 * the mach-o file.
1365 */
1366 while (total_size > 0) {
1367 flavor = *ts++;
1368 size = *ts++;
1369 if (UINT32_MAX-2 < size ||
1370 UINT32_MAX/sizeof(uint32_t) < size+2) {
1371 ret = LOAD_BADMACHO;
1372 goto done;
1373 }
1374 thread_size = (size+2)*sizeof(uint32_t);
1375 if (thread_size > total_size) {
1376 ret = LOAD_BADMACHO;
1377 goto done;
1378 }
1379 total_size -= thread_size;
1380 /*
1381 * Third argument is a kernel space pointer; it gets cast
1382 * to the appropriate type in machine_thread_set_state()
1383 * based on the value of flavor.
1384 */
1385 ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size);
1386 if (ret != KERN_SUCCESS) {
1387 ret = LOAD_FAILURE;
1388 goto done;
1389 }
1390 ts += size; /* ts is a (uint32_t *) */
1391 }
1392 ret = LOAD_SUCCESS;
1393
1394 done:
1395 if (local_ts != NULL) {
1396 kfree(local_ts, local_ts_size);
1397 local_ts = NULL;
1398 }
1399 return ret;
1400 }
1401
1402 static
1403 load_return_t
1404 load_threadstack(
1405 thread_t thread,
1406 uint32_t *ts,
1407 uint32_t total_size,
1408 mach_vm_offset_t *user_stack,
1409 int *customstack
1410 )
1411 {
1412 kern_return_t ret;
1413 uint32_t size;
1414 int flavor;
1415 uint32_t stack_size;
1416
1417 while (total_size > 0) {
1418 flavor = *ts++;
1419 size = *ts++;
1420 if (UINT32_MAX-2 < size ||
1421 UINT32_MAX/sizeof(uint32_t) < size+2)
1422 return (LOAD_BADMACHO);
1423 stack_size = (size+2)*sizeof(uint32_t);
1424 if (stack_size > total_size)
1425 return(LOAD_BADMACHO);
1426 total_size -= stack_size;
1427
1428 /*
1429 * Third argument is a kernel space pointer; it gets cast
1430 * to the appropriate type in thread_userstack() based on
1431 * the value of flavor.
1432 */
1433 ret = thread_userstack(thread, flavor, (thread_state_t)ts, size, user_stack, customstack);
1434 if (ret != KERN_SUCCESS) {
1435 return(LOAD_FAILURE);
1436 }
1437 ts += size; /* ts is a (uint32_t *) */
1438 }
1439 return(LOAD_SUCCESS);
1440 }
1441
1442 static
1443 load_return_t
1444 load_threadentry(
1445 thread_t thread,
1446 uint32_t *ts,
1447 uint32_t total_size,
1448 mach_vm_offset_t *entry_point
1449 )
1450 {
1451 kern_return_t ret;
1452 uint32_t size;
1453 int flavor;
1454 uint32_t entry_size;
1455
1456 /*
1457 * Set the thread state.
1458 */
1459 *entry_point = MACH_VM_MIN_ADDRESS;
1460 while (total_size > 0) {
1461 flavor = *ts++;
1462 size = *ts++;
1463 if (UINT32_MAX-2 < size ||
1464 UINT32_MAX/sizeof(uint32_t) < size+2)
1465 return (LOAD_BADMACHO);
1466 entry_size = (size+2)*sizeof(uint32_t);
1467 if (entry_size > total_size)
1468 return(LOAD_BADMACHO);
1469 total_size -= entry_size;
1470 /*
1471 * Third argument is a kernel space pointer; it gets cast
1472 * to the appropriate type in thread_entrypoint() based on
1473 * the value of flavor.
1474 */
1475 ret = thread_entrypoint(thread, flavor, (thread_state_t)ts, size, entry_point);
1476 if (ret != KERN_SUCCESS) {
1477 return(LOAD_FAILURE);
1478 }
1479 ts += size; /* ts is a (uint32_t *) */
1480 }
1481 return(LOAD_SUCCESS);
1482 }
1483
1484 struct macho_data {
1485 struct nameidata __nid;
1486 union macho_vnode_header {
1487 struct mach_header mach_header;
1488 struct fat_header fat_header;
1489 char __pad[512];
1490 } __header;
1491 };
1492
1493 static load_return_t
1494 load_dylinker(
1495 struct dylinker_command *lcp,
1496 integer_t archbits,
1497 vm_map_t map,
1498 thread_t thread,
1499 int depth,
1500 int64_t slide,
1501 load_result_t *result
1502 )
1503 {
1504 char *name;
1505 char *p;
1506 struct vnode *vp = NULLVP; /* set by get_macho_vnode() */
1507 struct mach_header *header;
1508 off_t file_offset = 0; /* set by get_macho_vnode() */
1509 off_t macho_size = 0; /* set by get_macho_vnode() */
1510 load_result_t *myresult;
1511 kern_return_t ret;
1512 struct macho_data *macho_data;
1513 struct {
1514 struct mach_header __header;
1515 load_result_t __myresult;
1516 struct macho_data __macho_data;
1517 } *dyld_data;
1518
1519 if (lcp->cmdsize < sizeof(*lcp))
1520 return (LOAD_BADMACHO);
1521
1522 name = (char *)lcp + lcp->name.offset;
1523 /*
1524 * Check for a proper null terminated string.
1525 */
1526 p = name;
1527 do {
1528 if (p >= (char *)lcp + lcp->cmdsize)
1529 return(LOAD_BADMACHO);
1530 } while (*p++);
1531
1532 /* Allocate wad-of-data from heap to reduce excessively deep stacks */
1533
1534 MALLOC(dyld_data, void *, sizeof (*dyld_data), M_TEMP, M_WAITOK);
1535 header = &dyld_data->__header;
1536 myresult = &dyld_data->__myresult;
1537 macho_data = &dyld_data->__macho_data;
1538
1539 ret = get_macho_vnode(name, archbits, header,
1540 &file_offset, &macho_size, macho_data, &vp);
1541 if (ret)
1542 goto novp_out;
1543
1544 *myresult = load_result_null;
1545
1546 /*
1547 * First try to map dyld in directly. This should work most of
1548 * the time since there shouldn't normally be something already
1549 * mapped to its address.
1550 */
1551
1552 ret = parse_machfile(vp, map, thread, header, file_offset,
1553 macho_size, depth, slide, 0, myresult);
1554
1555 /*
1556 * If it turned out something was in the way, then we'll take
1557 * take this longer path to preflight dyld's vm ranges, then
1558 * map it at a free location in the address space.
1559 */
1560
1561 if (ret == LOAD_NOSPACE) {
1562 mach_vm_offset_t dyl_start, map_addr;
1563 mach_vm_size_t dyl_length;
1564 int64_t slide_amount;
1565
1566 *myresult = load_result_null;
1567
1568 /*
1569 * Preflight parsing the Mach-O file with a NULL
1570 * map, which will return the ranges needed for a
1571 * subsequent map attempt (with a slide) in "myresult"
1572 */
1573 ret = parse_machfile(vp, VM_MAP_NULL, THREAD_NULL, header,
1574 file_offset, macho_size, depth,
1575 0 /* slide */, 0, myresult);
1576
1577 if (ret != LOAD_SUCCESS) {
1578 goto out;
1579 }
1580
1581 dyl_start = myresult->min_vm_addr;
1582 dyl_length = myresult->max_vm_addr - myresult->min_vm_addr;
1583
1584 dyl_length += slide;
1585
1586 /* To find an appropriate load address, do a quick allocation */
1587 map_addr = dyl_start;
1588 ret = mach_vm_allocate(map, &map_addr, dyl_length, VM_FLAGS_ANYWHERE);
1589 if (ret != KERN_SUCCESS) {
1590 ret = LOAD_NOSPACE;
1591 goto out;
1592 }
1593
1594 ret = mach_vm_deallocate(map, map_addr, dyl_length);
1595 if (ret != KERN_SUCCESS) {
1596 ret = LOAD_NOSPACE;
1597 goto out;
1598 }
1599
1600 if (map_addr < dyl_start)
1601 slide_amount = -(int64_t)(dyl_start - map_addr);
1602 else
1603 slide_amount = (int64_t)(map_addr - dyl_start);
1604
1605 slide_amount += slide;
1606
1607 *myresult = load_result_null;
1608
1609 ret = parse_machfile(vp, map, thread, header,
1610 file_offset, macho_size, depth,
1611 slide_amount, 0, myresult);
1612
1613 if (ret) {
1614 goto out;
1615 }
1616 }
1617
1618 if (ret == LOAD_SUCCESS) {
1619 result->dynlinker = TRUE;
1620 result->entry_point = myresult->entry_point;
1621 result->validentry = myresult->validentry;
1622 result->all_image_info_addr = myresult->all_image_info_addr;
1623 result->all_image_info_size = myresult->all_image_info_size;
1624 if (myresult->platform_binary) {
1625 result->csflags |= CS_DYLD_PLATFORM;
1626 }
1627 }
1628 out:
1629 vnode_put(vp);
1630 novp_out:
1631 FREE(dyld_data, M_TEMP);
1632 return (ret);
1633
1634 }
1635
1636 static load_return_t
1637 load_code_signature(
1638 struct linkedit_data_command *lcp,
1639 struct vnode *vp,
1640 off_t macho_offset,
1641 off_t macho_size,
1642 cpu_type_t cputype,
1643 load_result_t *result)
1644 {
1645 int ret;
1646 kern_return_t kr;
1647 vm_offset_t addr;
1648 int resid;
1649 struct cs_blob *blob;
1650 int error;
1651 vm_size_t blob_size;
1652
1653 addr = 0;
1654 blob = NULL;
1655
1656 if (lcp->cmdsize != sizeof (struct linkedit_data_command) ||
1657 lcp->dataoff + lcp->datasize > macho_size) {
1658 ret = LOAD_BADMACHO;
1659 goto out;
1660 }
1661
1662 blob = ubc_cs_blob_get(vp, cputype, macho_offset);
1663 if (blob != NULL) {
1664 /* we already have a blob for this vnode and cputype */
1665 if (blob->csb_cpu_type == cputype &&
1666 blob->csb_base_offset == macho_offset &&
1667 blob->csb_mem_size == lcp->datasize) {
1668 /* it matches the blob we want here, lets verify the version */
1669 if(0 != ubc_cs_generation_check(vp)) {
1670 if (0 != ubc_cs_blob_revalidate(vp, blob)) {
1671 ret = LOAD_FAILURE; /* set error same as from ubc_cs_blob_add */
1672 goto out;
1673 }
1674 }
1675 ret = LOAD_SUCCESS;
1676 } else {
1677 /* the blob has changed for this vnode: fail ! */
1678 ret = LOAD_BADMACHO;
1679 }
1680 goto out;
1681 }
1682
1683 blob_size = lcp->datasize;
1684 kr = ubc_cs_blob_allocate(&addr, &blob_size);
1685 if (kr != KERN_SUCCESS) {
1686 ret = LOAD_NOSPACE;
1687 goto out;
1688 }
1689
1690 resid = 0;
1691 error = vn_rdwr(UIO_READ,
1692 vp,
1693 (caddr_t) addr,
1694 lcp->datasize,
1695 macho_offset + lcp->dataoff,
1696 UIO_SYSSPACE,
1697 0,
1698 kauth_cred_get(),
1699 &resid,
1700 current_proc());
1701 if (error || resid != 0) {
1702 ret = LOAD_IOERROR;
1703 goto out;
1704 }
1705
1706 if (ubc_cs_blob_add(vp,
1707 cputype,
1708 macho_offset,
1709 addr,
1710 lcp->datasize)) {
1711 ret = LOAD_FAILURE;
1712 goto out;
1713 } else {
1714 /* ubc_cs_blob_add() has consumed "addr" */
1715 addr = 0;
1716 }
1717
1718 #if CHECK_CS_VALIDATION_BITMAP
1719 ubc_cs_validation_bitmap_allocate( vp );
1720 #endif
1721
1722 blob = ubc_cs_blob_get(vp, cputype, macho_offset);
1723
1724 ret = LOAD_SUCCESS;
1725 out:
1726 if (ret == LOAD_SUCCESS) {
1727 result->csflags |= blob->csb_flags;
1728 result->platform_binary = blob->csb_platform_binary;
1729 result->cs_end_offset = blob->csb_end_offset;
1730 }
1731 if (addr != 0) {
1732 ubc_cs_blob_deallocate(addr, blob_size);
1733 addr = 0;
1734 }
1735
1736 return ret;
1737 }
1738
1739
1740 #if CONFIG_CODE_DECRYPTION
1741
1742 static load_return_t
1743 set_code_unprotect(
1744 struct encryption_info_command *eip,
1745 caddr_t addr,
1746 vm_map_t map,
1747 int64_t slide,
1748 struct vnode *vp,
1749 cpu_type_t cputype,
1750 cpu_subtype_t cpusubtype)
1751 {
1752 int result, len;
1753 pager_crypt_info_t crypt_info;
1754 const char * cryptname = 0;
1755 char *vpath;
1756
1757 size_t offset;
1758 struct segment_command_64 *seg64;
1759 struct segment_command *seg32;
1760 vm_map_offset_t map_offset, map_size;
1761 kern_return_t kr;
1762
1763 if (eip->cmdsize < sizeof(*eip)) return LOAD_BADMACHO;
1764
1765 switch(eip->cryptid) {
1766 case 0:
1767 /* not encrypted, just an empty load command */
1768 return LOAD_SUCCESS;
1769 case 1:
1770 cryptname="com.apple.unfree";
1771 break;
1772 case 0x10:
1773 /* some random cryptid that you could manually put into
1774 * your binary if you want NULL */
1775 cryptname="com.apple.null";
1776 break;
1777 default:
1778 return LOAD_BADMACHO;
1779 }
1780
1781 if (map == VM_MAP_NULL) return (LOAD_SUCCESS);
1782 if (NULL == text_crypter_create) return LOAD_FAILURE;
1783
1784 MALLOC_ZONE(vpath, char *, MAXPATHLEN, M_NAMEI, M_WAITOK);
1785 if(vpath == NULL) return LOAD_FAILURE;
1786
1787 len = MAXPATHLEN;
1788 result = vn_getpath(vp, vpath, &len);
1789 if(result) {
1790 FREE_ZONE(vpath, MAXPATHLEN, M_NAMEI);
1791 return LOAD_FAILURE;
1792 }
1793
1794 /* set up decrypter first */
1795 crypt_file_data_t crypt_data = {
1796 .filename = vpath,
1797 .cputype = cputype,
1798 .cpusubtype = cpusubtype};
1799 kr=text_crypter_create(&crypt_info, cryptname, (void*)&crypt_data);
1800 FREE_ZONE(vpath, MAXPATHLEN, M_NAMEI);
1801
1802 if(kr) {
1803 printf("set_code_unprotect: unable to create decrypter %s, kr=%d\n",
1804 cryptname, kr);
1805 if (kr == kIOReturnNotPrivileged) {
1806 /* text encryption returned decryption failure */
1807 return(LOAD_DECRYPTFAIL);
1808 }else
1809 return LOAD_RESOURCE;
1810 }
1811
1812 /* this is terrible, but we have to rescan the load commands to find the
1813 * virtual address of this encrypted stuff. This code is gonna look like
1814 * the dyld source one day... */
1815 struct mach_header *header = (struct mach_header *)addr;
1816 size_t mach_header_sz = sizeof(struct mach_header);
1817 if (header->magic == MH_MAGIC_64 ||
1818 header->magic == MH_CIGAM_64) {
1819 mach_header_sz = sizeof(struct mach_header_64);
1820 }
1821 offset = mach_header_sz;
1822 uint32_t ncmds = header->ncmds;
1823 while (ncmds--) {
1824 /*
1825 * Get a pointer to the command.
1826 */
1827 struct load_command *lcp = (struct load_command *)(addr + offset);
1828 offset += lcp->cmdsize;
1829
1830 switch(lcp->cmd) {
1831 case LC_SEGMENT_64:
1832 seg64 = (struct segment_command_64 *)lcp;
1833 if ((seg64->fileoff <= eip->cryptoff) &&
1834 (seg64->fileoff+seg64->filesize >=
1835 eip->cryptoff+eip->cryptsize)) {
1836 map_offset = seg64->vmaddr + eip->cryptoff - seg64->fileoff + slide;
1837 map_size = eip->cryptsize;
1838 goto remap_now;
1839 }
1840 case LC_SEGMENT:
1841 seg32 = (struct segment_command *)lcp;
1842 if ((seg32->fileoff <= eip->cryptoff) &&
1843 (seg32->fileoff+seg32->filesize >=
1844 eip->cryptoff+eip->cryptsize)) {
1845 map_offset = seg32->vmaddr + eip->cryptoff - seg32->fileoff + slide;
1846 map_size = eip->cryptsize;
1847 goto remap_now;
1848 }
1849 }
1850 }
1851
1852 /* if we get here, did not find anything */
1853 return LOAD_BADMACHO;
1854
1855 remap_now:
1856 /* now remap using the decrypter */
1857 kr = vm_map_apple_protected(map, map_offset, map_offset+map_size, &crypt_info);
1858 if(kr) {
1859 printf("set_code_unprotect(): mapping failed with %x\n", kr);
1860 crypt_info.crypt_end(crypt_info.crypt_ops);
1861 return LOAD_PROTECT;
1862 }
1863
1864 return LOAD_SUCCESS;
1865 }
1866
1867 #endif
1868
1869 /*
1870 * This routine exists to support the load_dylinker().
1871 *
1872 * This routine has its own, separate, understanding of the FAT file format,
1873 * which is terrifically unfortunate.
1874 */
1875 static
1876 load_return_t
1877 get_macho_vnode(
1878 char *path,
1879 integer_t archbits,
1880 struct mach_header *mach_header,
1881 off_t *file_offset,
1882 off_t *macho_size,
1883 struct macho_data *data,
1884 struct vnode **vpp
1885 )
1886 {
1887 struct vnode *vp;
1888 vfs_context_t ctx = vfs_context_current();
1889 proc_t p = vfs_context_proc(ctx);
1890 kauth_cred_t kerncred;
1891 struct nameidata *ndp = &data->__nid;
1892 boolean_t is_fat;
1893 struct fat_arch fat_arch;
1894 int error;
1895 int resid;
1896 union macho_vnode_header *header = &data->__header;
1897 off_t fsize = (off_t)0;
1898
1899 /*
1900 * Capture the kernel credential for use in the actual read of the
1901 * file, since the user doing the execution may have execute rights
1902 * but not read rights, but to exec something, we have to either map
1903 * or read it into the new process address space, which requires
1904 * read rights. This is to deal with lack of common credential
1905 * serialization code which would treat NOCRED as "serialize 'root'".
1906 */
1907 kerncred = vfs_context_ucred(vfs_context_kernel());
1908
1909 /* init the namei data to point the file user's program name */
1910 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | LOCKLEAF, UIO_SYSSPACE, CAST_USER_ADDR_T(path), ctx);
1911
1912 if ((error = namei(ndp)) != 0) {
1913 if (error == ENOENT) {
1914 error = LOAD_ENOENT;
1915 } else {
1916 error = LOAD_FAILURE;
1917 }
1918 return(error);
1919 }
1920 nameidone(ndp);
1921 vp = ndp->ni_vp;
1922
1923 /* check for regular file */
1924 if (vp->v_type != VREG) {
1925 error = LOAD_PROTECT;
1926 goto bad1;
1927 }
1928
1929 /* get size */
1930 if ((error = vnode_size(vp, &fsize, ctx)) != 0) {
1931 error = LOAD_FAILURE;
1932 goto bad1;
1933 }
1934
1935 /* Check mount point */
1936 if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
1937 error = LOAD_PROTECT;
1938 goto bad1;
1939 }
1940
1941 /* check access */
1942 if ((error = vnode_authorize(vp, NULL, KAUTH_VNODE_EXECUTE | KAUTH_VNODE_READ_DATA, ctx)) != 0) {
1943 error = LOAD_PROTECT;
1944 goto bad1;
1945 }
1946
1947 /* try to open it */
1948 if ((error = VNOP_OPEN(vp, FREAD, ctx)) != 0) {
1949 error = LOAD_PROTECT;
1950 goto bad1;
1951 }
1952
1953 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)header, sizeof (*header), 0,
1954 UIO_SYSSPACE, IO_NODELOCKED, kerncred, &resid, p)) != 0) {
1955 error = LOAD_IOERROR;
1956 goto bad2;
1957 }
1958
1959 if (header->mach_header.magic == MH_MAGIC ||
1960 header->mach_header.magic == MH_MAGIC_64) {
1961 is_fat = FALSE;
1962 } else if (header->fat_header.magic == FAT_MAGIC ||
1963 header->fat_header.magic == FAT_CIGAM) {
1964 is_fat = TRUE;
1965 } else {
1966 error = LOAD_BADMACHO;
1967 goto bad2;
1968 }
1969
1970 if (is_fat) {
1971 /* Look up our architecture in the fat file. */
1972 error = fatfile_getarch_with_bits(vp, archbits,
1973 (vm_offset_t)(&header->fat_header), &fat_arch);
1974 if (error != LOAD_SUCCESS)
1975 goto bad2;
1976
1977 /* Read the Mach-O header out of it */
1978 error = vn_rdwr(UIO_READ, vp, (caddr_t)&header->mach_header,
1979 sizeof (header->mach_header), fat_arch.offset,
1980 UIO_SYSSPACE, IO_NODELOCKED, kerncred, &resid, p);
1981 if (error) {
1982 error = LOAD_IOERROR;
1983 goto bad2;
1984 }
1985
1986 /* Is this really a Mach-O? */
1987 if (header->mach_header.magic != MH_MAGIC &&
1988 header->mach_header.magic != MH_MAGIC_64) {
1989 error = LOAD_BADMACHO;
1990 goto bad2;
1991 }
1992
1993 *file_offset = fat_arch.offset;
1994 *macho_size = fat_arch.size;
1995 } else {
1996 /*
1997 * Force get_macho_vnode() to fail if the architecture bits
1998 * do not match the expected architecture bits. This in
1999 * turn causes load_dylinker() to fail for the same reason,
2000 * so it ensures the dynamic linker and the binary are in
2001 * lock-step. This is potentially bad, if we ever add to
2002 * the CPU_ARCH_* bits any bits that are desirable but not
2003 * required, since the dynamic linker might work, but we will
2004 * refuse to load it because of this check.
2005 */
2006 if ((cpu_type_t)(header->mach_header.cputype & CPU_ARCH_MASK) != archbits) {
2007 error = LOAD_BADARCH;
2008 goto bad2;
2009 }
2010
2011 *file_offset = 0;
2012 *macho_size = fsize;
2013 }
2014
2015 *mach_header = header->mach_header;
2016 *vpp = vp;
2017
2018 ubc_setsize(vp, fsize);
2019 return (error);
2020
2021 bad2:
2022 (void) VNOP_CLOSE(vp, FREAD, ctx);
2023 bad1:
2024 vnode_put(vp);
2025 return(error);
2026 }
mirror of XNU