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 */ 89extern 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 */ 93extern int get_map_nentries(vm_map_t); 94 95extern kern_return_t memory_object_signed(memory_object_control_t control, 96 boolean_t is_signed); 97 98/* An empty load_result_t */ 99static 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}; 118 119/* 120 * Prototypes of static functions. 121 */ 122static load_return_t 123parse_machfile( 124 struct vnode *vp, 125 vm_map_t map, 126 thread_t thread, 127 struct mach_header *header, 128 off_t file_offset, 129 off_t macho_size, 130 int depth, 131 int64_t slide, 132 int64_t dyld_slide, 133 load_result_t *result 134); 135 136static load_return_t 137load_segment( 138 struct load_command *lcp, 139 uint32_t filetype, 140 void *control, 141 off_t pager_offset, 142 off_t macho_size, 143 struct vnode *vp, 144 vm_map_t map, 145 int64_t slide, 146 load_result_t *result 147); 148 149static load_return_t 150load_uuid( 151 struct uuid_command *uulp, 152 char *command_end, 153 load_result_t *result 154); 155 156static load_return_t 157load_code_signature( 158 struct linkedit_data_command *lcp, 159 struct vnode *vp, 160 off_t macho_offset, 161 off_t macho_size, 162 cpu_type_t cputype, 163 load_result_t *result); 164 165#if CONFIG_CODE_DECRYPTION 166static load_return_t 167set_code_unprotect( 168 struct encryption_info_command *lcp, 169 caddr_t addr, 170 vm_map_t map, 171 int64_t slide, 172 struct vnode *vp, 173 cpu_type_t cputype, 174 cpu_subtype_t cpusubtype); 175#endif 176 177static 178load_return_t 179load_main( 180 struct entry_point_command *epc, 181 thread_t thread, 182 int64_t slide, 183 load_result_t *result 184); 185 186static load_return_t 187load_unixthread( 188 struct thread_command *tcp, 189 thread_t thread, 190 int64_t slide, 191 load_result_t *result 192); 193 194static load_return_t 195load_threadstate( 196 thread_t thread, 197 uint32_t *ts, 198 uint32_t total_size 199); 200 201static load_return_t 202load_threadstack( 203 thread_t thread, 204 uint32_t *ts, 205 uint32_t total_size, 206 mach_vm_offset_t *user_stack, 207 int *customstack 208); 209 210static load_return_t 211load_threadentry( 212 thread_t thread, 213 uint32_t *ts, 214 uint32_t total_size, 215 mach_vm_offset_t *entry_point 216); 217 218static load_return_t 219load_dylinker( 220 struct dylinker_command *lcp, 221 integer_t archbits, 222 vm_map_t map, 223 thread_t thread, 224 int depth, 225 int64_t slide, 226 load_result_t *result 227); 228 229struct macho_data; 230 231static load_return_t 232get_macho_vnode( 233 char *path, 234 integer_t archbits, 235 struct mach_header *mach_header, 236 off_t *file_offset, 237 off_t *macho_size, 238 struct macho_data *macho_data, 239 struct vnode **vpp 240); 241 242static inline void 243widen_segment_command(const struct segment_command *scp32, 244 struct segment_command_64 *scp) 245{ 246 scp->cmd = scp32->cmd; 247 scp->cmdsize = scp32->cmdsize; 248 bcopy(scp32->segname, scp->segname, sizeof(scp->segname)); 249 scp->vmaddr = scp32->vmaddr; 250 scp->vmsize = scp32->vmsize; 251 scp->fileoff = scp32->fileoff; 252 scp->filesize = scp32->filesize; 253 scp->maxprot = scp32->maxprot; 254 scp->initprot = scp32->initprot; 255 scp->nsects = scp32->nsects; 256 scp->flags = scp32->flags; 257} 258 259static void 260note_all_image_info_section(const struct segment_command_64 *scp, 261 boolean_t is64, size_t section_size, const void *sections, 262 int64_t slide, load_result_t *result) 263{ 264 const union { 265 struct section s32; 266 struct section_64 s64; 267 } *sectionp; 268 unsigned int i; 269 270 if (strncmp(scp->segname, "__DATA", sizeof(scp->segname)) != 0) 271 return; 272 for (i = 0; i < scp->nsects; ++i) { 273 sectionp = (const void *) 274 ((const char *)sections + section_size * i); 275 if (0 == strncmp(sectionp->s64.sectname, "__all_image_info", 276 sizeof(sectionp->s64.sectname))) { 277 result->all_image_info_addr = 278 is64 ? sectionp->s64.addr : sectionp->s32.addr; 279 result->all_image_info_addr += slide; 280 result->all_image_info_size = 281 is64 ? sectionp->s64.size : sectionp->s32.size; 282 return; 283 } 284 } 285} 286 287load_return_t 288load_machfile( 289 struct image_params *imgp, 290 struct mach_header *header, 291 thread_t thread, 292 vm_map_t new_map, 293 load_result_t *result 294) 295{ 296 struct vnode *vp = imgp->ip_vp; 297 off_t file_offset = imgp->ip_arch_offset; 298 off_t macho_size = imgp->ip_arch_size; 299 off_t file_size = imgp->ip_vattr->va_data_size; 300 301 pmap_t pmap = 0; /* protected by create_map */ 302 vm_map_t map; 303 vm_map_t old_map; 304 task_t old_task = TASK_NULL; /* protected by create_map */ 305 load_result_t myresult; 306 load_return_t lret; 307 boolean_t create_map = FALSE; 308 int spawn = (imgp->ip_flags & IMGPF_SPAWN); 309 task_t task = current_task(); 310 proc_t p = current_proc(); 311 mach_vm_offset_t aslr_offset = 0; 312 mach_vm_offset_t dyld_aslr_offset = 0; 313 kern_return_t kret; 314 315 if (macho_size > file_size) { 316 return(LOAD_BADMACHO); 317 } 318 319 if (new_map == VM_MAP_NULL) { 320 create_map = TRUE; 321 old_task = current_task(); 322 } 323 324 /* 325 * If we are spawning, we have created backing objects for the process 326 * already, which include non-lazily creating the task map. So we 327 * are going to switch out the task map with one appropriate for the 328 * bitness of the image being loaded. 329 */ 330 if (spawn) { 331 create_map = TRUE; 332 old_task = get_threadtask(thread); 333 } 334 335 if (create_map) { 336 pmap = pmap_create(get_task_ledger(task), (vm_map_size_t) 0, 337 (imgp->ip_flags & IMGPF_IS_64BIT)); 338 pal_switch_pmap(thread, pmap, imgp->ip_flags & IMGPF_IS_64BIT); 339 map = vm_map_create(pmap, 340 0, 341 vm_compute_max_offset((imgp->ip_flags & IMGPF_IS_64BIT)), 342 TRUE); 343 } else 344 map = new_map; 345 346#ifndef CONFIG_ENFORCE_SIGNED_CODE 347 /* This turns off faulting for executable pages, which allows 348 * to circumvent Code Signing Enforcement. The per process 349 * flag (CS_ENFORCEMENT) is not set yet, but we can use the 350 * global flag. 351 */ 352 if ( !cs_enforcement(NULL) && (header->flags & MH_ALLOW_STACK_EXECUTION) ) 353 vm_map_disable_NX(map); 354#endif 355 356 /* Forcibly disallow execution from data pages on even if the arch 357 * normally permits it. */ 358 if ((header->flags & MH_NO_HEAP_EXECUTION) && !(imgp->ip_flags & IMGPF_ALLOW_DATA_EXEC)) 359 vm_map_disallow_data_exec(map); 360 361 /* 362 * Compute a random offset for ASLR, and an independent random offset for dyld. 363 */ 364 if (!(imgp->ip_flags & IMGPF_DISABLE_ASLR)) { 365 uint64_t max_slide_pages; 366 367 max_slide_pages = vm_map_get_max_aslr_slide_pages(map); 368 369 aslr_offset = random(); 370 aslr_offset %= max_slide_pages; 371 aslr_offset <<= vm_map_page_shift(map); 372 373 dyld_aslr_offset = random(); 374 dyld_aslr_offset %= max_slide_pages; 375 dyld_aslr_offset <<= vm_map_page_shift(map); 376 } 377 378 if (!result) 379 result = &myresult; 380 381 *result = load_result_null; 382 383 lret = parse_machfile(vp, map, thread, header, file_offset, macho_size, 384 0, (int64_t)aslr_offset, (int64_t)dyld_aslr_offset, result); 385 386 if (lret != LOAD_SUCCESS) { 387 if (create_map) { 388 vm_map_deallocate(map); /* will lose pmap reference too */ 389 } 390 return(lret); 391 } 392 393 /* 394 * For 64-bit users, check for presence of a 4GB page zero 395 * which will enable the kernel to share the user's address space 396 * and hence avoid TLB flushes on kernel entry/exit 397 */ 398 399 if ((imgp->ip_flags & IMGPF_IS_64BIT) && 400 vm_map_has_4GB_pagezero(map)) { 401 vm_map_set_4GB_pagezero(map); 402 } 403 /* 404 * Commit to new map. 405 * 406 * Swap the new map for the old, which consumes our new map 407 * reference but each leaves us responsible for the old_map reference. 408 * That lets us get off the pmap associated with it, and 409 * then we can release it. 410 */ 411 412 if (create_map) { 413 /* 414 * If this is an exec, then we are going to destroy the old 415 * task, and it's correct to halt it; if it's spawn, the 416 * task is not yet running, and it makes no sense. 417 */ 418 if (!spawn) { 419 /* 420 * Mark the task as halting and start the other 421 * threads towards terminating themselves. Then 422 * make sure any threads waiting for a process 423 * transition get informed that we are committed to 424 * this transition, and then finally complete the 425 * task halting (wait for threads and then cleanup 426 * task resources). 427 * 428 * NOTE: task_start_halt() makes sure that no new 429 * threads are created in the task during the transition. 430 * We need to mark the workqueue as exiting before we 431 * wait for threads to terminate (at the end of which 432 * we no longer have a prohibition on thread creation). 433 * 434 * Finally, clean up any lingering workqueue data structures 435 * that may have been left behind by the workqueue threads 436 * as they exited (and then clean up the work queue itself). 437 */ 438 kret = task_start_halt(task); 439 if (kret != KERN_SUCCESS) { 440 return(kret); 441 } 442 proc_transcommit(p, 0); 443 workqueue_mark_exiting(p); 444 task_complete_halt(task); 445 workqueue_exit(p); 446 } 447 old_map = swap_task_map(old_task, thread, map, !spawn); 448 vm_map_clear_4GB_pagezero(old_map); 449 vm_map_deallocate(old_map); 450 } 451 return(LOAD_SUCCESS); 452} 453 454/* 455 * The file size of a mach-o file is limited to 32 bits; this is because 456 * this is the limit on the kalloc() of enough bytes for a mach_header and 457 * the contents of its sizeofcmds, which is currently constrained to 32 458 * bits in the file format itself. We read into the kernel buffer the 459 * commands section, and then parse it in order to parse the mach-o file 460 * format load_command segment(s). We are only interested in a subset of 461 * the total set of possible commands. If "map"==VM_MAP_NULL or 462 * "thread"==THREAD_NULL, do not make permament VM modifications, 463 * just preflight the parse. 464 */ 465static 466load_return_t 467parse_machfile( 468 struct vnode *vp, 469 vm_map_t map, 470 thread_t thread, 471 struct mach_header *header, 472 off_t file_offset, 473 off_t macho_size, 474 int depth, 475 int64_t aslr_offset, 476 int64_t dyld_aslr_offset, 477 load_result_t *result 478) 479{ 480 uint32_t ncmds; 481 struct load_command *lcp; 482 struct dylinker_command *dlp = 0; 483 integer_t dlarchbits = 0; 484 void * control; 485 load_return_t ret = LOAD_SUCCESS; 486 caddr_t addr; 487 void * kl_addr; 488 vm_size_t size,kl_size; 489 size_t offset; 490 size_t oldoffset; /* for overflow check */ 491 int pass; 492 proc_t p = current_proc(); /* XXXX */ 493 int error; 494 int resid=0; 495 size_t mach_header_sz = sizeof(struct mach_header); 496 boolean_t abi64; 497 boolean_t got_code_signatures = FALSE; 498 int64_t slide = 0; 499 500 if (header->magic == MH_MAGIC_64 || 501 header->magic == MH_CIGAM_64) { 502 mach_header_sz = sizeof(struct mach_header_64); 503 } 504 505 /* 506 * Break infinite recursion 507 */ 508 if (depth > 6) { 509 return(LOAD_FAILURE); 510 } 511 512 depth++; 513 514 /* 515 * Check to see if right machine type. 516 */ 517 if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != (cpu_type() & ~CPU_ARCH_MASK)) || 518 !grade_binary(header->cputype, 519 header->cpusubtype & ~CPU_SUBTYPE_MASK)) 520 return(LOAD_BADARCH); 521 522 abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64); 523 524 switch (header->filetype) { 525 526 case MH_OBJECT: 527 case MH_EXECUTE: 528 case MH_PRELOAD: 529 if (depth != 1) { 530 return (LOAD_FAILURE); 531 } 532 break; 533 534 case MH_FVMLIB: 535 case MH_DYLIB: 536 if (depth == 1) { 537 return (LOAD_FAILURE); 538 } 539 break; 540 541 case MH_DYLINKER: 542 if (depth != 2) { 543 return (LOAD_FAILURE); 544 } 545 break; 546 547 default: 548 return (LOAD_FAILURE); 549 } 550 551 /* 552 * Get the pager for the file. 553 */ 554 control = ubc_getobject(vp, UBC_FLAGS_NONE); 555 556 /* 557 * Map portion that must be accessible directly into 558 * kernel's map. 559 */ 560 if ((off_t)(mach_header_sz + header->sizeofcmds) > macho_size) 561 return(LOAD_BADMACHO); 562 563 /* 564 * Round size of Mach-O commands up to page boundry. 565 */ 566 size = round_page(mach_header_sz + header->sizeofcmds); 567 if (size <= 0) 568 return(LOAD_BADMACHO); 569 570 /* 571 * Map the load commands into kernel memory. 572 */ 573 addr = 0; 574 kl_size = size; 575 kl_addr = kalloc(size); 576 addr = (caddr_t)kl_addr; 577 if (addr == NULL) 578 return(LOAD_NOSPACE); 579 580 error = vn_rdwr(UIO_READ, vp, addr, size, file_offset, 581 UIO_SYSSPACE, 0, kauth_cred_get(), &resid, p); 582 if (error) { 583 if (kl_addr ) 584 kfree(kl_addr, kl_size); 585 return(LOAD_IOERROR); 586 } 587 588 /* 589 * For PIE and dyld, slide everything by the ASLR offset. 590 */ 591 if ((header->flags & MH_PIE) || (header->filetype == MH_DYLINKER)) { 592 slide = aslr_offset; 593 } 594 595 /* 596 * Scan through the commands, processing each one as necessary. 597 * We parse in three passes through the headers: 598 * 1: thread state, uuid, code signature 599 * 2: segments 600 * 3: dyld, encryption, check entry point 601 */ 602 603 for (pass = 1; pass <= 3; pass++) { 604 605 /* 606 * Check that the entry point is contained in an executable segments 607 */ 608 if ((pass == 3) && (result->validentry == 0)) { 609 thread_state_initialize(thread); 610 ret = LOAD_FAILURE; 611 break; 612 } 613 614 /* 615 * Loop through each of the load_commands indicated by the 616 * Mach-O header; if an absurd value is provided, we just 617 * run off the end of the reserved section by incrementing 618 * the offset too far, so we are implicitly fail-safe. 619 */ 620 offset = mach_header_sz; 621 ncmds = header->ncmds; 622 623 while (ncmds--) { 624 /* 625 * Get a pointer to the command. 626 */ 627 lcp = (struct load_command *)(addr + offset); 628 oldoffset = offset; 629 offset += lcp->cmdsize; 630 631 /* 632 * Perform prevalidation of the struct load_command 633 * before we attempt to use its contents. Invalid 634 * values are ones which result in an overflow, or 635 * which can not possibly be valid commands, or which 636 * straddle or exist past the reserved section at the 637 * start of the image. 638 */ 639 if (oldoffset > offset || 640 lcp->cmdsize < sizeof(struct load_command) || 641 offset > header->sizeofcmds + mach_header_sz) { 642 ret = LOAD_BADMACHO; 643 break; 644 } 645 646 /* 647 * Act on struct load_command's for which kernel 648 * intervention is required. 649 */ 650 switch(lcp->cmd) { 651 case LC_SEGMENT: 652 if (pass != 2) 653 break; 654 655 if (abi64) { 656 /* 657 * Having an LC_SEGMENT command for the 658 * wrong ABI is invalid <rdar://problem/11021230> 659 */ 660 ret = LOAD_BADMACHO; 661 break; 662 } 663 664 ret = load_segment(lcp, 665 header->filetype, 666 control, 667 file_offset, 668 macho_size, 669 vp, 670 map, 671 slide, 672 result); 673 break; 674 case LC_SEGMENT_64: 675 if (pass != 2) 676 break; 677 678 if (!abi64) { 679 /* 680 * Having an LC_SEGMENT_64 command for the 681 * wrong ABI is invalid <rdar://problem/11021230> 682 */ 683 ret = LOAD_BADMACHO; 684 break; 685 } 686 687 ret = load_segment(lcp, 688 header->filetype, 689 control, 690 file_offset, 691 macho_size, 692 vp, 693 map, 694 slide, 695 result); 696 break; 697 case LC_UNIXTHREAD: 698 if (pass != 1) 699 break; 700 ret = load_unixthread( 701 (struct thread_command *) lcp, 702 thread, 703 slide, 704 result); 705 break; 706 case LC_MAIN: 707 if (pass != 1) 708 break; 709 if (depth != 1) 710 break; 711 ret = load_main( 712 (struct entry_point_command *) lcp, 713 thread, 714 slide, 715 result); 716 break; 717 case LC_LOAD_DYLINKER: 718 if (pass != 3) 719 break; 720 if ((depth == 1) && (dlp == 0)) { 721 dlp = (struct dylinker_command *)lcp; 722 dlarchbits = (header->cputype & CPU_ARCH_MASK); 723 } else { 724 ret = LOAD_FAILURE; 725 } 726 break; 727 case LC_UUID: 728 if (pass == 1 && depth == 1) { 729 ret = load_uuid((struct uuid_command *) lcp, 730 (char *)addr + mach_header_sz + header->sizeofcmds, 731 result); 732 } 733 break; 734 case LC_CODE_SIGNATURE: 735 /* CODE SIGNING */ 736 if (pass != 1) 737 break; 738 /* pager -> uip -> 739 load signatures & store in uip 740 set VM object "signed_pages" 741 */ 742 ret = load_code_signature( 743 (struct linkedit_data_command *) lcp, 744 vp, 745 file_offset, 746 macho_size, 747 header->cputype, 748 (depth == 1) ? result : NULL); 749 if (ret != LOAD_SUCCESS) { 750 printf("proc %d: load code signature error %d " 751 "for file \"%s\"\n", 752 p->p_pid, ret, vp->v_name); 753 ret = LOAD_SUCCESS; /* ignore error */ 754 } else { 755 got_code_signatures = TRUE; 756 } 757 break; 758#if CONFIG_CODE_DECRYPTION 759 case LC_ENCRYPTION_INFO: 760 case LC_ENCRYPTION_INFO_64: 761 if (pass != 3) 762 break; 763 ret = set_code_unprotect( 764 (struct encryption_info_command *) lcp, 765 addr, map, slide, vp, 766 header->cputype, header->cpusubtype); 767 if (ret != LOAD_SUCCESS) { 768 printf("proc %d: set_code_unprotect() error %d " 769 "for file \"%s\"\n", 770 p->p_pid, ret, vp->v_name); 771 /* 772 * Don't let the app run if it's 773 * encrypted but we failed to set up the 774 * decrypter. If the keys are missing it will 775 * return LOAD_DECRYPTFAIL. 776 */ 777 if (ret == LOAD_DECRYPTFAIL) { 778 /* failed to load due to missing FP keys */ 779 proc_lock(p); 780 p->p_lflag |= P_LTERM_DECRYPTFAIL; 781 proc_unlock(p); 782 } 783 psignal(p, SIGKILL); 784 } 785 break; 786#endif 787 default: 788 /* Other commands are ignored by the kernel */ 789 ret = LOAD_SUCCESS; 790 break; 791 } 792 if (ret != LOAD_SUCCESS) 793 break; 794 } 795 if (ret != LOAD_SUCCESS) 796 break; 797 } 798 if (ret == LOAD_SUCCESS) { 799 if (! got_code_signatures) { 800 struct cs_blob *blob; 801 /* no embedded signatures: look for detached ones */ 802 blob = ubc_cs_blob_get(vp, -1, file_offset); 803 if (blob != NULL) { 804 /* get flags to be applied to the process */ 805 result->csflags |= blob->csb_flags; 806 } 807 } 808 809 /* Make sure if we need dyld, we got it */ 810 if (result->needs_dynlinker && !dlp) { 811 ret = LOAD_FAILURE; 812 } 813 814 if ((ret == LOAD_SUCCESS) && (dlp != 0)) { 815 /* 816 * load the dylinker, and slide it by the independent DYLD ASLR 817 * offset regardless of the PIE-ness of the main binary. 818 */ 819 820 ret = load_dylinker(dlp, dlarchbits, map, thread, depth, 821 dyld_aslr_offset, result); 822 } 823 824 if((ret == LOAD_SUCCESS) && (depth == 1)) { 825 if (result->thread_count == 0) { 826 ret = LOAD_FAILURE; 827 } 828 } 829 } 830 831 if (kl_addr ) 832 kfree(kl_addr, kl_size); 833 834 return(ret); 835} 836 837#if CONFIG_CODE_DECRYPTION 838 839#define APPLE_UNPROTECTED_HEADER_SIZE (3 * PAGE_SIZE_64) 840 841static load_return_t 842unprotect_segment( 843 uint64_t file_off, 844 uint64_t file_size, 845 struct vnode *vp, 846 off_t macho_offset, 847 vm_map_t map, 848 vm_map_offset_t map_addr, 849 vm_map_size_t map_size) 850{ 851 kern_return_t kr; 852 853 /* 854 * The first APPLE_UNPROTECTED_HEADER_SIZE bytes (from offset 0 of 855 * this part of a Universal binary) are not protected... 856 * The rest needs to be "transformed". 857 */ 858 if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE && 859 file_off + file_size <= APPLE_UNPROTECTED_HEADER_SIZE) { 860 /* it's all unprotected, nothing to do... */ 861 kr = KERN_SUCCESS; 862 } else { 863 if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE) { 864 /* 865 * We start mapping in the unprotected area. 866 * Skip the unprotected part... 867 */ 868 vm_map_offset_t delta; 869 870 delta = APPLE_UNPROTECTED_HEADER_SIZE; 871 delta -= file_off; 872 map_addr += delta; 873 map_size -= delta; 874 } 875 /* ... transform the rest of the mapping. */ 876 struct pager_crypt_info crypt_info; 877 crypt_info.page_decrypt = dsmos_page_transform; 878 crypt_info.crypt_ops = NULL; 879 crypt_info.crypt_end = NULL; 880#pragma unused(vp, macho_offset) 881 crypt_info.crypt_ops = (void *)0x2e69cf40; 882 kr = vm_map_apple_protected(map, 883 map_addr, 884 map_addr + map_size, 885 &crypt_info); 886 } 887 888 if (kr != KERN_SUCCESS) { 889 return LOAD_FAILURE; 890 } 891 return LOAD_SUCCESS; 892} 893#else /* CONFIG_CODE_DECRYPTION */ 894static load_return_t 895unprotect_segment( 896 __unused uint64_t file_off, 897 __unused uint64_t file_size, 898 __unused struct vnode *vp, 899 __unused off_t macho_offset, 900 __unused vm_map_t map, 901 __unused vm_map_offset_t map_addr, 902 __unused vm_map_size_t map_size) 903{ 904 return LOAD_SUCCESS; 905} 906#endif /* CONFIG_CODE_DECRYPTION */ 907 908static 909load_return_t 910load_segment( 911 struct load_command *lcp, 912 uint32_t filetype, 913 void * control, 914 off_t pager_offset, 915 off_t macho_size, 916 struct vnode *vp, 917 vm_map_t map, 918 int64_t slide, 919 load_result_t *result 920) 921{ 922 struct segment_command_64 segment_command, *scp; 923 kern_return_t ret; 924 vm_map_offset_t map_addr, map_offset; 925 vm_map_size_t map_size, seg_size, delta_size; 926 vm_prot_t initprot; 927 vm_prot_t maxprot; 928 size_t segment_command_size, total_section_size, 929 single_section_size; 930 boolean_t prohibit_pagezero_mapping = FALSE; 931 932 if (LC_SEGMENT_64 == lcp->cmd) { 933 segment_command_size = sizeof(struct segment_command_64); 934 single_section_size = sizeof(struct section_64); 935 } else { 936 segment_command_size = sizeof(struct segment_command); 937 single_section_size = sizeof(struct section); 938 } 939 if (lcp->cmdsize < segment_command_size) 940 return (LOAD_BADMACHO); 941 total_section_size = lcp->cmdsize - segment_command_size; 942 943 if (LC_SEGMENT_64 == lcp->cmd) 944 scp = (struct segment_command_64 *)lcp; 945 else { 946 scp = &segment_command; 947 widen_segment_command((struct segment_command *)lcp, scp); 948 } 949 950 /* 951 * Make sure what we get from the file is really ours (as specified 952 * by macho_size). 953 */ 954 if (scp->fileoff + scp->filesize < scp->fileoff || 955 scp->fileoff + scp->filesize > (uint64_t)macho_size) 956 return (LOAD_BADMACHO); 957 /* 958 * Ensure that the number of sections specified would fit 959 * within the load command size. 960 */ 961 if (total_section_size / single_section_size < scp->nsects) 962 return (LOAD_BADMACHO); 963 /* 964 * Make sure the segment is page-aligned in the file. 965 */ 966 if ((scp->fileoff & PAGE_MASK_64) != 0) 967 return (LOAD_BADMACHO); 968 969 /* 970 * Round sizes to page size. 971 */ 972 seg_size = round_page_64(scp->vmsize); 973 map_size = round_page_64(scp->filesize); 974 map_addr = trunc_page_64(scp->vmaddr); /* JVXXX note that in XNU TOT this is round instead of trunc for 64 bits */ 975 976 seg_size = vm_map_round_page(seg_size, vm_map_page_mask(map)); 977 map_size = vm_map_round_page(map_size, vm_map_page_mask(map)); 978 979 if (seg_size == 0) 980 return (KERN_SUCCESS); 981 if (map_addr == 0 && 982 map_size == 0 && 983 seg_size != 0 && 984 (scp->initprot & VM_PROT_ALL) == VM_PROT_NONE && 985 (scp->maxprot & VM_PROT_ALL) == VM_PROT_NONE) { 986 /* 987 * For PIE, extend page zero rather than moving it. Extending 988 * page zero keeps early allocations from falling predictably 989 * between the end of page zero and the beginning of the first 990 * slid segment. 991 */ 992 seg_size += slide; 993 slide = 0; 994 /* XXX (4596982) this interferes with Rosetta, so limit to 64-bit tasks */ 995 if (scp->cmd == LC_SEGMENT_64) { 996 prohibit_pagezero_mapping = TRUE; 997 } 998 999 if (prohibit_pagezero_mapping) { 1000 /* 1001 * This is a "page zero" segment: it starts at address 0, 1002 * is not mapped from the binary file and is not accessible. 1003 * User-space should never be able to access that memory, so 1004 * make it completely off limits by raising the VM map's 1005 * minimum offset. 1006 */ 1007 ret = vm_map_raise_min_offset(map, seg_size); 1008 if (ret != KERN_SUCCESS) { 1009 return (LOAD_FAILURE); 1010 } 1011 return (LOAD_SUCCESS); 1012 } 1013 } 1014 1015 /* If a non-zero slide was specified by the caller, apply now */ 1016 map_addr += slide; 1017 1018 if (map_addr < result->min_vm_addr) 1019 result->min_vm_addr = map_addr; 1020 if (map_addr+seg_size > result->max_vm_addr) 1021 result->max_vm_addr = map_addr+seg_size; 1022 1023 if (map == VM_MAP_NULL) 1024 return (LOAD_SUCCESS); 1025 1026 map_offset = pager_offset + scp->fileoff; /* limited to 32 bits */ 1027 1028 if (map_size > 0) { 1029 initprot = (scp->initprot) & VM_PROT_ALL; 1030 maxprot = (scp->maxprot) & VM_PROT_ALL; 1031 /* 1032 * Map a copy of the file into the address space. 1033 */ 1034 ret = vm_map_enter_mem_object_control(map, 1035 &map_addr, map_size, (mach_vm_offset_t)0, 1036 VM_FLAGS_FIXED, control, map_offset, TRUE, 1037 initprot, maxprot, 1038 VM_INHERIT_DEFAULT); 1039 if (ret != KERN_SUCCESS) { 1040 return (LOAD_NOSPACE); 1041 } 1042 1043 /* 1044 * If the file didn't end on a page boundary, 1045 * we need to zero the leftover. 1046 */ 1047 delta_size = map_size - scp->filesize; 1048#if FIXME 1049 if (delta_size > 0) { 1050 mach_vm_offset_t tmp; 1051 1052 ret = mach_vm_allocate(kernel_map, &tmp, delta_size, VM_FLAGS_ANYWHERE); 1053 if (ret != KERN_SUCCESS) 1054 return(LOAD_RESOURCE); 1055 1056 if (copyout(tmp, map_addr + scp->filesize, 1057 delta_size)) { 1058 (void) mach_vm_deallocate( 1059 kernel_map, tmp, delta_size); 1060 return (LOAD_FAILURE); 1061 } 1062 1063 (void) mach_vm_deallocate(kernel_map, tmp, delta_size); 1064 } 1065#endif /* FIXME */ 1066 } 1067 1068 /* 1069 * If the virtual size of the segment is greater 1070 * than the size from the file, we need to allocate 1071 * zero fill memory for the rest. 1072 */ 1073 delta_size = seg_size - map_size; 1074 if (delta_size > 0) { 1075 mach_vm_offset_t tmp = map_addr + map_size; 1076 1077 ret = mach_vm_map(map, &tmp, delta_size, 0, VM_FLAGS_FIXED, 1078 NULL, 0, FALSE, 1079 scp->initprot, scp->maxprot, 1080 VM_INHERIT_DEFAULT); 1081 if (ret != KERN_SUCCESS) 1082 return(LOAD_NOSPACE); 1083 } 1084 1085 if ( (scp->fileoff == 0) && (scp->filesize != 0) ) 1086 result->mach_header = map_addr; 1087 1088 if (scp->flags & SG_PROTECTED_VERSION_1) { 1089 ret = unprotect_segment(scp->fileoff, 1090 scp->filesize, 1091 vp, 1092 pager_offset, 1093 map, 1094 map_addr, 1095 map_size); 1096 } else { 1097 ret = LOAD_SUCCESS; 1098 } 1099 if (LOAD_SUCCESS == ret && filetype == MH_DYLINKER && 1100 result->all_image_info_addr == MACH_VM_MIN_ADDRESS) 1101 note_all_image_info_section(scp, 1102 LC_SEGMENT_64 == lcp->cmd, single_section_size, 1103 (const char *)lcp + segment_command_size, slide, result); 1104 1105 if ((result->entry_point >= map_addr) && (result->entry_point < (map_addr + map_size))) 1106 result->validentry = 1; 1107 1108 return ret; 1109} 1110 1111static 1112load_return_t 1113load_uuid( 1114 struct uuid_command *uulp, 1115 char *command_end, 1116 load_result_t *result 1117) 1118{ 1119 /* 1120 * We need to check the following for this command: 1121 * - The command size should be atleast the size of struct uuid_command 1122 * - The UUID part of the command should be completely within the mach-o header 1123 */ 1124 1125 if ((uulp->cmdsize < sizeof(struct uuid_command)) || 1126 (((char *)uulp + sizeof(struct uuid_command)) > command_end)) { 1127 return (LOAD_BADMACHO); 1128 } 1129 1130 memcpy(&result->uuid[0], &uulp->uuid[0], sizeof(result->uuid)); 1131 return (LOAD_SUCCESS); 1132} 1133 1134static 1135load_return_t 1136load_main( 1137 struct entry_point_command *epc, 1138 thread_t thread, 1139 int64_t slide, 1140 load_result_t *result 1141) 1142{ 1143 mach_vm_offset_t addr; 1144 kern_return_t ret; 1145 1146 if (epc->cmdsize < sizeof(*epc)) 1147 return (LOAD_BADMACHO); 1148 if (result->thread_count != 0) { 1149 printf("load_main: already have a thread!"); 1150 return (LOAD_FAILURE); 1151 } 1152 1153 if (thread == THREAD_NULL) 1154 return (LOAD_SUCCESS); 1155 1156 /* LC_MAIN specifies stack size but not location */ 1157 if (epc->stacksize) { 1158 result->prog_stack_size = 1; 1159 result->user_stack_size = epc->stacksize; 1160 } else { 1161 result->prog_stack_size = 0; 1162 result->user_stack_size = MAXSSIZ; 1163 } 1164 result->prog_allocated_stack = 0; 1165 1166 /* use default location for stack */ 1167 ret = thread_userstackdefault(thread, &addr); 1168 if (ret != KERN_SUCCESS) 1169 return(LOAD_FAILURE); 1170 1171 /* The stack slides down from the default location */ 1172 result->user_stack = addr; 1173 result->user_stack -= slide; 1174 1175 /* kernel does *not* use entryoff from LC_MAIN. Dyld uses it. */ 1176 result->needs_dynlinker = TRUE; 1177 result->validentry = TRUE; 1178 1179 ret = thread_state_initialize( thread ); 1180 if (ret != KERN_SUCCESS) { 1181 return(LOAD_FAILURE); 1182 } 1183 1184 result->unixproc = TRUE; 1185 result->thread_count++; 1186 1187 return(LOAD_SUCCESS); 1188} 1189 1190 1191static 1192load_return_t 1193load_unixthread( 1194 struct thread_command *tcp, 1195 thread_t thread, 1196 int64_t slide, 1197 load_result_t *result 1198) 1199{ 1200 load_return_t ret; 1201 int customstack =0; 1202 mach_vm_offset_t addr; 1203 1204 if (tcp->cmdsize < sizeof(*tcp)) 1205 return (LOAD_BADMACHO); 1206 if (result->thread_count != 0) { 1207 printf("load_unixthread: already have a thread!"); 1208 return (LOAD_FAILURE); 1209 } 1210 1211 if (thread == THREAD_NULL) 1212 return (LOAD_SUCCESS); 1213 1214 ret = load_threadstack(thread, 1215 (uint32_t *)(((vm_offset_t)tcp) + 1216 sizeof(struct thread_command)), 1217 tcp->cmdsize - sizeof(struct thread_command), 1218 &addr, 1219 &customstack); 1220 if (ret != LOAD_SUCCESS) 1221 return(ret); 1222 1223 /* LC_UNIXTHREAD optionally specifies stack size and location */ 1224 1225 if (customstack) { 1226 result->prog_stack_size = 0; /* unknown */ 1227 result->prog_allocated_stack = 1; 1228 } else { 1229 result->prog_allocated_stack = 0; 1230 result->prog_stack_size = 0; 1231 result->user_stack_size = MAXSSIZ; 1232 } 1233 1234 /* The stack slides down from the default location */ 1235 result->user_stack = addr; 1236 result->user_stack -= slide; 1237 1238 ret = load_threadentry(thread, 1239 (uint32_t *)(((vm_offset_t)tcp) + 1240 sizeof(struct thread_command)), 1241 tcp->cmdsize - sizeof(struct thread_command), 1242 &addr); 1243 if (ret != LOAD_SUCCESS) 1244 return(ret); 1245 1246 result->entry_point = addr; 1247 result->entry_point += slide; 1248 1249 ret = load_threadstate(thread, 1250 (uint32_t *)(((vm_offset_t)tcp) + 1251 sizeof(struct thread_command)), 1252 tcp->cmdsize - sizeof(struct thread_command)); 1253 if (ret != LOAD_SUCCESS) 1254 return (ret); 1255 1256 result->unixproc = TRUE; 1257 result->thread_count++; 1258 1259 return(LOAD_SUCCESS); 1260} 1261 1262static 1263load_return_t 1264load_threadstate( 1265 thread_t thread, 1266 uint32_t *ts, 1267 uint32_t total_size 1268) 1269{ 1270 kern_return_t ret; 1271 uint32_t size; 1272 int flavor; 1273 uint32_t thread_size; 1274 1275 ret = thread_state_initialize( thread ); 1276 if (ret != KERN_SUCCESS) { 1277 return(LOAD_FAILURE); 1278 } 1279 1280 /* 1281 * Set the new thread state; iterate through the state flavors in 1282 * the mach-o file. 1283 */ 1284 while (total_size > 0) { 1285 flavor = *ts++; 1286 size = *ts++; 1287 if (UINT32_MAX-2 < size || 1288 UINT32_MAX/sizeof(uint32_t) < size+2) 1289 return (LOAD_BADMACHO); 1290 thread_size = (size+2)*sizeof(uint32_t); 1291 if (thread_size > total_size) 1292 return(LOAD_BADMACHO); 1293 total_size -= thread_size; 1294 /* 1295 * Third argument is a kernel space pointer; it gets cast 1296 * to the appropriate type in machine_thread_set_state() 1297 * based on the value of flavor. 1298 */ 1299 ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size); 1300 if (ret != KERN_SUCCESS) { 1301 return(LOAD_FAILURE); 1302 } 1303 ts += size; /* ts is a (uint32_t *) */ 1304 } 1305 return(LOAD_SUCCESS); 1306} 1307 1308static 1309load_return_t 1310load_threadstack( 1311 thread_t thread, 1312 uint32_t *ts, 1313 uint32_t total_size, 1314 mach_vm_offset_t *user_stack, 1315 int *customstack 1316) 1317{ 1318 kern_return_t ret; 1319 uint32_t size; 1320 int flavor; 1321 uint32_t stack_size; 1322 1323 while (total_size > 0) { 1324 flavor = *ts++; 1325 size = *ts++; 1326 if (UINT32_MAX-2 < size || 1327 UINT32_MAX/sizeof(uint32_t) < size+2) 1328 return (LOAD_BADMACHO); 1329 stack_size = (size+2)*sizeof(uint32_t); 1330 if (stack_size > total_size) 1331 return(LOAD_BADMACHO); 1332 total_size -= stack_size; 1333 1334 /* 1335 * Third argument is a kernel space pointer; it gets cast 1336 * to the appropriate type in thread_userstack() based on 1337 * the value of flavor. 1338 */ 1339 ret = thread_userstack(thread, flavor, (thread_state_t)ts, size, user_stack, customstack); 1340 if (ret != KERN_SUCCESS) { 1341 return(LOAD_FAILURE); 1342 } 1343 ts += size; /* ts is a (uint32_t *) */ 1344 } 1345 return(LOAD_SUCCESS); 1346} 1347 1348static 1349load_return_t 1350load_threadentry( 1351 thread_t thread, 1352 uint32_t *ts, 1353 uint32_t total_size, 1354 mach_vm_offset_t *entry_point 1355) 1356{ 1357 kern_return_t ret; 1358 uint32_t size; 1359 int flavor; 1360 uint32_t entry_size; 1361 1362 /* 1363 * Set the thread state. 1364 */ 1365 *entry_point = MACH_VM_MIN_ADDRESS; 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 return (LOAD_BADMACHO); 1372 entry_size = (size+2)*sizeof(uint32_t); 1373 if (entry_size > total_size) 1374 return(LOAD_BADMACHO); 1375 total_size -= entry_size; 1376 /* 1377 * Third argument is a kernel space pointer; it gets cast 1378 * to the appropriate type in thread_entrypoint() based on 1379 * the value of flavor. 1380 */ 1381 ret = thread_entrypoint(thread, flavor, (thread_state_t)ts, size, entry_point); 1382 if (ret != KERN_SUCCESS) { 1383 return(LOAD_FAILURE); 1384 } 1385 ts += size; /* ts is a (uint32_t *) */ 1386 } 1387 return(LOAD_SUCCESS); 1388} 1389 1390struct macho_data { 1391 struct nameidata __nid; 1392 union macho_vnode_header { 1393 struct mach_header mach_header; 1394 struct fat_header fat_header; 1395 char __pad[512]; 1396 } __header; 1397}; 1398 1399static load_return_t 1400load_dylinker( 1401 struct dylinker_command *lcp, 1402 integer_t archbits, 1403 vm_map_t map, 1404 thread_t thread, 1405 int depth, 1406 int64_t slide, 1407 load_result_t *result 1408) 1409{ 1410 char *name; 1411 char *p; 1412 struct vnode *vp = NULLVP; /* set by get_macho_vnode() */ 1413 struct mach_header *header; 1414 off_t file_offset = 0; /* set by get_macho_vnode() */ 1415 off_t macho_size = 0; /* set by get_macho_vnode() */ 1416 load_result_t *myresult; 1417 kern_return_t ret; 1418 struct macho_data *macho_data; 1419 struct { 1420 struct mach_header __header; 1421 load_result_t __myresult; 1422 struct macho_data __macho_data; 1423 } *dyld_data; 1424 1425 if (lcp->cmdsize < sizeof(*lcp)) 1426 return (LOAD_BADMACHO); 1427 1428 name = (char *)lcp + lcp->name.offset; 1429 /* 1430 * Check for a proper null terminated string. 1431 */ 1432 p = name; 1433 do { 1434 if (p >= (char *)lcp + lcp->cmdsize) 1435 return(LOAD_BADMACHO); 1436 } while (*p++); 1437 1438 /* Allocate wad-of-data from heap to reduce excessively deep stacks */ 1439 1440 MALLOC(dyld_data, void *, sizeof (*dyld_data), M_TEMP, M_WAITOK); 1441 header = &dyld_data->__header; 1442 myresult = &dyld_data->__myresult; 1443 macho_data = &dyld_data->__macho_data; 1444 1445 ret = get_macho_vnode(name, archbits, header, 1446 &file_offset, &macho_size, macho_data, &vp); 1447 if (ret) 1448 goto novp_out; 1449 1450 *myresult = load_result_null; 1451 1452 /* 1453 * First try to map dyld in directly. This should work most of 1454 * the time since there shouldn't normally be something already 1455 * mapped to its address. 1456 */ 1457 1458 ret = parse_machfile(vp, map, thread, header, file_offset, 1459 macho_size, depth, slide, 0, myresult); 1460 1461 /* 1462 * If it turned out something was in the way, then we'll take 1463 * take this longer path to preflight dyld's vm ranges, then 1464 * map it at a free location in the address space. 1465 */ 1466 1467 if (ret == LOAD_NOSPACE) { 1468 mach_vm_offset_t dyl_start, map_addr; 1469 mach_vm_size_t dyl_length; 1470 int64_t slide_amount; 1471 1472 *myresult = load_result_null; 1473 1474 /* 1475 * Preflight parsing the Mach-O file with a NULL 1476 * map, which will return the ranges needed for a 1477 * subsequent map attempt (with a slide) in "myresult" 1478 */ 1479 ret = parse_machfile(vp, VM_MAP_NULL, THREAD_NULL, header, 1480 file_offset, macho_size, depth, 1481 0 /* slide */, 0, myresult); 1482 1483 if (ret != LOAD_SUCCESS) { 1484 goto out; 1485 } 1486 1487 dyl_start = myresult->min_vm_addr; 1488 dyl_length = myresult->max_vm_addr - myresult->min_vm_addr; 1489 1490 dyl_length += slide; 1491 1492 /* To find an appropriate load address, do a quick allocation */ 1493 map_addr = dyl_start; 1494 ret = mach_vm_allocate(map, &map_addr, dyl_length, VM_FLAGS_ANYWHERE); 1495 if (ret != KERN_SUCCESS) { 1496 ret = LOAD_NOSPACE; 1497 goto out; 1498 } 1499 1500 ret = mach_vm_deallocate(map, map_addr, dyl_length); 1501 if (ret != KERN_SUCCESS) { 1502 ret = LOAD_NOSPACE; 1503 goto out; 1504 } 1505 1506 if (map_addr < dyl_start) 1507 slide_amount = -(int64_t)(dyl_start - map_addr); 1508 else 1509 slide_amount = (int64_t)(map_addr - dyl_start); 1510 1511 slide_amount += slide; 1512 1513 *myresult = load_result_null; 1514 1515 ret = parse_machfile(vp, map, thread, header, 1516 file_offset, macho_size, depth, 1517 slide_amount, 0, myresult); 1518 1519 if (ret) { 1520 goto out; 1521 } 1522 } 1523 1524 if (ret == LOAD_SUCCESS) { 1525 result->dynlinker = TRUE; 1526 result->entry_point = myresult->entry_point; 1527 result->validentry = myresult->validentry; 1528 result->all_image_info_addr = myresult->all_image_info_addr; 1529 result->all_image_info_size = myresult->all_image_info_size; 1530 } 1531out: 1532 vnode_put(vp); 1533novp_out: 1534 FREE(dyld_data, M_TEMP); 1535 return (ret); 1536 1537} 1538 1539static load_return_t 1540load_code_signature( 1541 struct linkedit_data_command *lcp, 1542 struct vnode *vp, 1543 off_t macho_offset, 1544 off_t macho_size, 1545 cpu_type_t cputype, 1546 load_result_t *result) 1547{ 1548 int ret; 1549 kern_return_t kr; 1550 vm_offset_t addr; 1551 int resid; 1552 struct cs_blob *blob; 1553 int error; 1554 vm_size_t blob_size; 1555 1556 addr = 0; 1557 blob = NULL; 1558 1559 if (lcp->cmdsize != sizeof (struct linkedit_data_command) || 1560 lcp->dataoff + lcp->datasize > macho_size) { 1561 ret = LOAD_BADMACHO; 1562 goto out; 1563 } 1564 1565 blob = ubc_cs_blob_get(vp, cputype, -1); 1566 if (blob != NULL && 1567 blob->csb_cpu_type == cputype && 1568 blob->csb_base_offset == macho_offset && 1569 blob->csb_blob_offset == lcp->dataoff && 1570 blob->csb_mem_size == lcp->datasize) { 1571 /* 1572 * we already have a blob for this vnode and cputype 1573 * and its at the same offset in Mach-O. Optimize to 1574 * not reload, revalidate, and compare the blob hashes. 1575 * Security will not be compromised, but we might miss 1576 * out on some messagetracer info about the differences 1577 * in blob content. 1578 */ 1579 ret = LOAD_SUCCESS; 1580 goto out; 1581 } 1582 1583 blob_size = lcp->datasize; 1584 kr = ubc_cs_blob_allocate(&addr, &blob_size); 1585 if (kr != KERN_SUCCESS) { 1586 ret = LOAD_NOSPACE; 1587 goto out; 1588 } 1589 1590 resid = 0; 1591 error = vn_rdwr(UIO_READ, 1592 vp, 1593 (caddr_t) addr, 1594 lcp->datasize, 1595 macho_offset + lcp->dataoff, 1596 UIO_SYSSPACE, 1597 0, 1598 kauth_cred_get(), 1599 &resid, 1600 current_proc()); 1601 if (error || resid != 0) { 1602 ret = LOAD_IOERROR; 1603 goto out; 1604 } 1605 1606 if (ubc_cs_blob_add(vp, 1607 cputype, 1608 macho_offset, 1609 addr, 1610 lcp->dataoff, 1611 lcp->datasize)) { 1612 ret = LOAD_FAILURE; 1613 goto out; 1614 } else { 1615 /* ubc_cs_blob_add() has consumed "addr" */ 1616 addr = 0; 1617 } 1618 1619#if CHECK_CS_VALIDATION_BITMAP 1620 ubc_cs_validation_bitmap_allocate( vp ); 1621#endif 1622 1623 blob = ubc_cs_blob_get(vp, cputype, -1); 1624 1625 ret = LOAD_SUCCESS; 1626out: 1627 if (result && ret == LOAD_SUCCESS) { 1628 result->csflags |= blob->csb_flags; 1629 } 1630 if (addr != 0) { 1631 ubc_cs_blob_deallocate(addr, blob_size); 1632 addr = 0; 1633 } 1634 1635 return ret; 1636} 1637 1638 1639#if CONFIG_CODE_DECRYPTION 1640 1641static load_return_t 1642set_code_unprotect( 1643 struct encryption_info_command *eip, 1644 caddr_t addr, 1645 vm_map_t map, 1646 int64_t slide, 1647 struct vnode *vp, 1648 cpu_type_t cputype, 1649 cpu_subtype_t cpusubtype) 1650{ 1651 int result, len; 1652 pager_crypt_info_t crypt_info; 1653 const char * cryptname = 0; 1654 char *vpath; 1655 1656 size_t offset; 1657 struct segment_command_64 *seg64; 1658 struct segment_command *seg32; 1659 vm_map_offset_t map_offset, map_size; 1660 kern_return_t kr; 1661 1662 if (eip->cmdsize < sizeof(*eip)) return LOAD_BADMACHO; 1663 1664 switch(eip->cryptid) { 1665 case 0: 1666 /* not encrypted, just an empty load command */ 1667 return LOAD_SUCCESS; 1668 case 1: 1669 cryptname="com.apple.unfree"; 1670 break; 1671 case 0x10: 1672 /* some random cryptid that you could manually put into 1673 * your binary if you want NULL */ 1674 cryptname="com.apple.null"; 1675 break; 1676 default: 1677 return LOAD_BADMACHO; 1678 } 1679 1680 if (map == VM_MAP_NULL) return (LOAD_SUCCESS); 1681 if (NULL == text_crypter_create) return LOAD_FAILURE; 1682 1683 MALLOC_ZONE(vpath, char *, MAXPATHLEN, M_NAMEI, M_WAITOK); 1684 if(vpath == NULL) return LOAD_FAILURE; 1685 1686 len = MAXPATHLEN; 1687 result = vn_getpath(vp, vpath, &len); 1688 if(result) { 1689 FREE_ZONE(vpath, MAXPATHLEN, M_NAMEI); 1690 return LOAD_FAILURE; 1691 } 1692 1693 /* set up decrypter first */ 1694 crypt_file_data_t crypt_data = { 1695 .filename = vpath, 1696 .cputype = cputype, 1697 .cpusubtype = cpusubtype}; 1698 kr=text_crypter_create(&crypt_info, cryptname, (void*)&crypt_data); 1699 FREE_ZONE(vpath, MAXPATHLEN, M_NAMEI); 1700 1701 if(kr) { 1702 printf("set_code_unprotect: unable to create decrypter %s, kr=%d\n", 1703 cryptname, kr); 1704 if (kr == kIOReturnNotPrivileged) { 1705 /* text encryption returned decryption failure */ 1706 return(LOAD_DECRYPTFAIL); 1707 }else 1708 return LOAD_RESOURCE; 1709 } 1710 1711 /* this is terrible, but we have to rescan the load commands to find the 1712 * virtual address of this encrypted stuff. This code is gonna look like 1713 * the dyld source one day... */ 1714 struct mach_header *header = (struct mach_header *)addr; 1715 size_t mach_header_sz = sizeof(struct mach_header); 1716 if (header->magic == MH_MAGIC_64 || 1717 header->magic == MH_CIGAM_64) { 1718 mach_header_sz = sizeof(struct mach_header_64); 1719 } 1720 offset = mach_header_sz; 1721 uint32_t ncmds = header->ncmds; 1722 while (ncmds--) { 1723 /* 1724 * Get a pointer to the command. 1725 */ 1726 struct load_command *lcp = (struct load_command *)(addr + offset); 1727 offset += lcp->cmdsize; 1728 1729 switch(lcp->cmd) { 1730 case LC_SEGMENT_64: 1731 seg64 = (struct segment_command_64 *)lcp; 1732 if ((seg64->fileoff <= eip->cryptoff) && 1733 (seg64->fileoff+seg64->filesize >= 1734 eip->cryptoff+eip->cryptsize)) { 1735 map_offset = seg64->vmaddr + eip->cryptoff - seg64->fileoff + slide; 1736 map_size = eip->cryptsize; 1737 goto remap_now; 1738 } 1739 case LC_SEGMENT: 1740 seg32 = (struct segment_command *)lcp; 1741 if ((seg32->fileoff <= eip->cryptoff) && 1742 (seg32->fileoff+seg32->filesize >= 1743 eip->cryptoff+eip->cryptsize)) { 1744 map_offset = seg32->vmaddr + eip->cryptoff - seg32->fileoff + slide; 1745 map_size = eip->cryptsize; 1746 goto remap_now; 1747 } 1748 } 1749 } 1750 1751 /* if we get here, did not find anything */ 1752 return LOAD_BADMACHO; 1753 1754remap_now: 1755 /* now remap using the decrypter */ 1756 kr = vm_map_apple_protected(map, map_offset, map_offset+map_size, &crypt_info); 1757 if(kr) { 1758 printf("set_code_unprotect(): mapping failed with %x\n", kr); 1759 crypt_info.crypt_end(crypt_info.crypt_ops); 1760 return LOAD_PROTECT; 1761 } 1762 1763 return LOAD_SUCCESS; 1764} 1765 1766#endif 1767 1768/* 1769 * This routine exists to support the load_dylinker(). 1770 * 1771 * This routine has its own, separate, understanding of the FAT file format, 1772 * which is terrifically unfortunate. 1773 */ 1774static 1775load_return_t 1776get_macho_vnode( 1777 char *path, 1778 integer_t archbits, 1779 struct mach_header *mach_header, 1780 off_t *file_offset, 1781 off_t *macho_size, 1782 struct macho_data *data, 1783 struct vnode **vpp 1784) 1785{ 1786 struct vnode *vp; 1787 vfs_context_t ctx = vfs_context_current(); 1788 proc_t p = vfs_context_proc(ctx); 1789 kauth_cred_t kerncred; 1790 struct nameidata *ndp = &data->__nid; 1791 boolean_t is_fat; 1792 struct fat_arch fat_arch; 1793 int error; 1794 int resid; 1795 union macho_vnode_header *header = &data->__header; 1796 off_t fsize = (off_t)0; 1797 1798 /* 1799 * Capture the kernel credential for use in the actual read of the 1800 * file, since the user doing the execution may have execute rights 1801 * but not read rights, but to exec something, we have to either map 1802 * or read it into the new process address space, which requires 1803 * read rights. This is to deal with lack of common credential 1804 * serialization code which would treat NOCRED as "serialize 'root'". 1805 */ 1806 kerncred = vfs_context_ucred(vfs_context_kernel()); 1807 1808 /* init the namei data to point the file user's program name */ 1809 NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | LOCKLEAF, UIO_SYSSPACE, CAST_USER_ADDR_T(path), ctx); 1810 1811 if ((error = namei(ndp)) != 0) { 1812 if (error == ENOENT) { 1813 error = LOAD_ENOENT; 1814 } else { 1815 error = LOAD_FAILURE; 1816 } 1817 return(error); 1818 } 1819 nameidone(ndp); 1820 vp = ndp->ni_vp; 1821 1822 /* check for regular file */ 1823 if (vp->v_type != VREG) { 1824 error = LOAD_PROTECT; 1825 goto bad1; 1826 } 1827 1828 /* get size */ 1829 if ((error = vnode_size(vp, &fsize, ctx)) != 0) { 1830 error = LOAD_FAILURE; 1831 goto bad1; 1832 } 1833 1834 /* Check mount point */ 1835 if (vp->v_mount->mnt_flag & MNT_NOEXEC) { 1836 error = LOAD_PROTECT; 1837 goto bad1; 1838 } 1839 1840 /* check access */ 1841 if ((error = vnode_authorize(vp, NULL, KAUTH_VNODE_EXECUTE | KAUTH_VNODE_READ_DATA, ctx)) != 0) { 1842 error = LOAD_PROTECT; 1843 goto bad1; 1844 } 1845 1846 /* try to open it */ 1847 if ((error = VNOP_OPEN(vp, FREAD, ctx)) != 0) { 1848 error = LOAD_PROTECT; 1849 goto bad1; 1850 } 1851 1852 if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)header, sizeof (*header), 0, 1853 UIO_SYSSPACE, IO_NODELOCKED, kerncred, &resid, p)) != 0) { 1854 error = LOAD_IOERROR; 1855 goto bad2; 1856 } 1857 1858 if (header->mach_header.magic == MH_MAGIC || 1859 header->mach_header.magic == MH_MAGIC_64) { 1860 is_fat = FALSE; 1861 } else if (header->fat_header.magic == FAT_MAGIC || 1862 header->fat_header.magic == FAT_CIGAM) { 1863 is_fat = TRUE; 1864 } else { 1865 error = LOAD_BADMACHO; 1866 goto bad2; 1867 } 1868 1869 if (is_fat) { 1870 /* Look up our architecture in the fat file. */ 1871 error = fatfile_getarch_with_bits(vp, archbits, 1872 (vm_offset_t)(&header->fat_header), &fat_arch); 1873 if (error != LOAD_SUCCESS) 1874 goto bad2; 1875 1876 /* Read the Mach-O header out of it */ 1877 error = vn_rdwr(UIO_READ, vp, (caddr_t)&header->mach_header, 1878 sizeof (header->mach_header), fat_arch.offset, 1879 UIO_SYSSPACE, IO_NODELOCKED, kerncred, &resid, p); 1880 if (error) { 1881 error = LOAD_IOERROR; 1882 goto bad2; 1883 } 1884 1885 /* Is this really a Mach-O? */ 1886 if (header->mach_header.magic != MH_MAGIC && 1887 header->mach_header.magic != MH_MAGIC_64) { 1888 error = LOAD_BADMACHO; 1889 goto bad2; 1890 } 1891 1892 *file_offset = fat_arch.offset; 1893 *macho_size = fat_arch.size; 1894 } else { 1895 /* 1896 * Force get_macho_vnode() to fail if the architecture bits 1897 * do not match the expected architecture bits. This in 1898 * turn causes load_dylinker() to fail for the same reason, 1899 * so it ensures the dynamic linker and the binary are in 1900 * lock-step. This is potentially bad, if we ever add to 1901 * the CPU_ARCH_* bits any bits that are desirable but not 1902 * required, since the dynamic linker might work, but we will 1903 * refuse to load it because of this check. 1904 */ 1905 if ((cpu_type_t)(header->mach_header.cputype & CPU_ARCH_MASK) != archbits) { 1906 error = LOAD_BADARCH; 1907 goto bad2; 1908 } 1909 1910 *file_offset = 0; 1911 *macho_size = fsize; 1912 } 1913 1914 *mach_header = header->mach_header; 1915 *vpp = vp; 1916 1917 ubc_setsize(vp, fsize); 1918 return (error); 1919 1920bad2: 1921 (void) VNOP_CLOSE(vp, FREAD, ctx); 1922bad1: 1923 vnode_put(vp); 1924 return(error); 1925} 1926