X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/13f56ec4e58bf8687e2a68032c093c0213dd519b..c6bf4f310a33a9262d455ea4d3f0630b1255e3fe:/bsd/kern/mach_loader.c diff --git a/bsd/kern/mach_loader.c b/bsd/kern/mach_loader.c index 47253a898..d51e05c70 100644 --- a/bsd/kern/mach_loader.c +++ b/bsd/kern/mach_loader.c @@ -2,7 +2,7 @@ * Copyright (c) 2000-2010 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,7 +22,7 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* @@ -49,10 +49,14 @@ #include #include #include +#include +#include +#include +#include #include -#include /* vm_allocate() */ -#include /* mach_vm_allocate() */ +#include /* vm_allocate() */ +#include /* mach_vm_allocate() */ #include #include #include @@ -61,6 +65,7 @@ #include #include +#include #include #include #include @@ -78,48 +83,51 @@ #include #include #include -#include +#include +#include /* for kIOReturnNotPrivileged */ -/* - * XXX vm/pmap.h should not treat these prototypes as MACH_KERNEL_PRIVATE - * when KERNEL is defined. - */ -extern pmap_t pmap_create(vm_map_size_t size, boolean_t is_64bit); -extern void pmap_switch(pmap_t); +#include /* - * XXX kern/thread.h should not treat these prototypes as MACH_KERNEL_PRIVATE + * XXX vm/pmap.h should not treat these prototypes as MACH_KERNEL_PRIVATE * when KERNEL is defined. */ -extern kern_return_t thread_setstatus(thread_t thread, int flavor, - thread_state_t tstate, - mach_msg_type_number_t count); - -extern kern_return_t thread_state_initialize(thread_t thread); - +extern pmap_t pmap_create_options(ledger_t ledger, vm_map_size_t size, + unsigned int flags); /* XXX should have prototypes in a shared header file */ -extern int get_map_nentries(vm_map_t); +extern int get_map_nentries(vm_map_t); -extern kern_return_t memory_object_signed(memory_object_control_t control, - boolean_t is_signed); +extern kern_return_t memory_object_signed(memory_object_control_t control, + boolean_t is_signed); /* An empty load_result_t */ -static load_result_t load_result_null = { +static const load_result_t load_result_null = { .mach_header = MACH_VM_MIN_ADDRESS, .entry_point = MACH_VM_MIN_ADDRESS, .user_stack = MACH_VM_MIN_ADDRESS, + .user_stack_size = 0, + .user_stack_alloc = MACH_VM_MIN_ADDRESS, + .user_stack_alloc_size = 0, .all_image_info_addr = MACH_VM_MIN_ADDRESS, .all_image_info_size = 0, .thread_count = 0, .unixproc = 0, .dynlinker = 0, - .customstack = 0, + .needs_dynlinker = 0, .validentry = 0, + .using_lcmain = 0, + .is_64bit_addr = 0, + .is_64bit_data = 0, + .custom_stack = 0, .csflags = 0, + .has_pagezero = 0, .uuid = { 0 }, .min_vm_addr = MACH_VM_MAX_ADDRESS, - .max_vm_addr = MACH_VM_MIN_ADDRESS + .max_vm_addr = MACH_VM_MIN_ADDRESS, + .cs_end_offset = 0, + .threadstate = NULL, + .threadstate_sz = 0 }; /* @@ -127,103 +135,154 @@ static load_result_t load_result_null = { */ static load_return_t parse_machfile( - struct vnode *vp, - vm_map_t map, - thread_t thread, - struct mach_header *header, - off_t file_offset, - off_t macho_size, - int depth, - int64_t slide, - load_result_t *result -); + struct vnode *vp, + vm_map_t map, + thread_t thread, + struct mach_header *header, + off_t file_offset, + off_t macho_size, + int depth, + int64_t slide, + int64_t dyld_slide, + load_result_t *result, + load_result_t *binresult, + struct image_params *imgp + ); static load_return_t load_segment( - struct load_command *lcp, - uint32_t filetype, - void *control, - off_t pager_offset, - off_t macho_size, - struct vnode *vp, - vm_map_t map, - int64_t slide, - load_result_t *result -); + struct load_command *lcp, + uint32_t filetype, + void *control, + off_t pager_offset, + off_t macho_size, + struct vnode *vp, + vm_map_t map, + int64_t slide, + load_result_t *result + ); + +static load_return_t +load_uuid( + struct uuid_command *uulp, + char *command_end, + load_result_t *result + ); + +static load_return_t +load_version( + struct version_min_command *vmc, + boolean_t *found_version_cmd, + load_result_t *result + ); static load_return_t load_code_signature( - struct linkedit_data_command *lcp, - struct vnode *vp, - off_t macho_offset, - off_t macho_size, - cpu_type_t cputype, - load_result_t *result); - + struct linkedit_data_command *lcp, + struct vnode *vp, + off_t macho_offset, + off_t macho_size, + cpu_type_t cputype, + load_result_t *result, + struct image_params *imgp); + #if CONFIG_CODE_DECRYPTION static load_return_t set_code_unprotect( - struct encryption_info_command *lcp, - caddr_t addr, - vm_map_t map, - struct vnode *vp); + struct encryption_info_command *lcp, + caddr_t addr, + vm_map_t map, + int64_t slide, + struct vnode *vp, + off_t macho_offset, + cpu_type_t cputype, + cpu_subtype_t cpusubtype); #endif +static +load_return_t +load_main( + struct entry_point_command *epc, + thread_t thread, + int64_t slide, + load_result_t *result + ); + +static +load_return_t +setup_driver_main( + thread_t thread, + int64_t slide, + load_result_t *result + ); + static load_return_t load_unixthread( - struct thread_command *tcp, - thread_t thread, - int64_t slide, - load_result_t *result -); + struct thread_command *tcp, + thread_t thread, + int64_t slide, + load_result_t *result + ); static load_return_t load_threadstate( - thread_t thread, - uint32_t *ts, - uint32_t total_size -); + thread_t thread, + uint32_t *ts, + uint32_t total_size, + load_result_t * + ); static load_return_t load_threadstack( - thread_t thread, - uint32_t *ts, - uint32_t total_size, - mach_vm_offset_t *user_stack, - int *customstack -); + thread_t thread, + uint32_t *ts, + uint32_t total_size, + mach_vm_offset_t *user_stack, + int *customstack, + load_result_t *result + ); static load_return_t load_threadentry( - thread_t thread, - uint32_t *ts, - uint32_t total_size, - mach_vm_offset_t *entry_point -); + thread_t thread, + uint32_t *ts, + uint32_t total_size, + mach_vm_offset_t *entry_point + ); static load_return_t load_dylinker( - struct dylinker_command *lcp, - integer_t archbits, - vm_map_t map, - thread_t thread, - int depth, - int64_t slide, - load_result_t *result -); + struct dylinker_command *lcp, + integer_t archbits, + vm_map_t map, + thread_t thread, + int depth, + int64_t slide, + load_result_t *result, + struct image_params *imgp + ); + +#if __x86_64__ +extern int bootarg_no32exec; +static boolean_t +check_if_simulator_binary( + struct image_params *imgp, + off_t file_offset, + off_t macho_size); +#endif struct macho_data; static load_return_t get_macho_vnode( - char *path, - integer_t archbits, - struct mach_header *mach_header, - off_t *file_offset, - off_t *macho_size, - struct macho_data *macho_data, - struct vnode **vpp -); + const char *path, + integer_t archbits, + struct mach_header *mach_header, + off_t *file_offset, + off_t *macho_size, + struct macho_data *macho_data, + struct vnode **vpp + ); static inline void widen_segment_command(const struct segment_command *scp32, @@ -253,8 +312,10 @@ note_all_image_info_section(const struct segment_command_64 *scp, } *sectionp; unsigned int i; - if (strncmp(scp->segname, "__DATA", sizeof(scp->segname)) != 0) + + if (strncmp(scp->segname, "__DATA", sizeof(scp->segname)) != 0) { return; + } for (i = 0; i < scp->nsects; ++i) { sectionp = (const void *) ((const char *)sections + section_size * i); @@ -270,156 +331,261 @@ note_all_image_info_section(const struct segment_command_64 *scp, } } +#if __arm64__ +/* + * Allow bypassing some security rules (hard pagezero, no write+execute) + * in exchange for better binary compatibility for legacy apps built + * before 16KB-alignment was enforced. + */ +const int fourk_binary_compatibility_unsafe = TRUE; +const int fourk_binary_compatibility_allow_wx = FALSE; +#endif /* __arm64__ */ + load_return_t load_machfile( - struct image_params *imgp, - struct mach_header *header, - thread_t thread, - vm_map_t new_map, - load_result_t *result -) + struct image_params *imgp, + struct mach_header *header, + thread_t thread, + vm_map_t *mapp, + load_result_t *result + ) { - struct vnode *vp = imgp->ip_vp; - off_t file_offset = imgp->ip_arch_offset; - off_t macho_size = imgp->ip_arch_size; - - pmap_t pmap = 0; /* protected by create_map */ - vm_map_t map; - vm_map_t old_map; - task_t old_task = TASK_NULL; /* protected by create_map */ - load_result_t myresult; - load_return_t lret; - boolean_t create_map = FALSE; - int spawn = (imgp->ip_flags & IMGPF_SPAWN); + struct vnode *vp = imgp->ip_vp; + off_t file_offset = imgp->ip_arch_offset; + off_t macho_size = imgp->ip_arch_size; + off_t file_size = imgp->ip_vattr->va_data_size; + pmap_t pmap = 0; /* protected by create_map */ + vm_map_t map; + load_result_t myresult; + load_return_t lret; + boolean_t enforce_hard_pagezero = TRUE; + int in_exec = (imgp->ip_flags & IMGPF_EXEC); task_t task = current_task(); - proc_t p = current_proc(); - mach_vm_offset_t aslr_offset = 0; - kern_return_t kret; - - if (new_map == VM_MAP_NULL) { - create_map = TRUE; - old_task = current_task(); + int64_t aslr_page_offset = 0; + int64_t dyld_aslr_page_offset = 0; + int64_t aslr_section_size = 0; + int64_t aslr_section_offset = 0; + kern_return_t kret; + unsigned int pmap_flags = 0; + + if (macho_size > file_size) { + return LOAD_BADMACHO; } - /* - * If we are spawning, we have created backing objects for the process - * already, which include non-lazily creating the task map. So we - * are going to switch out the task map with one appropriate for the - * bitness of the image being loaded. + result->is_64bit_addr = ((imgp->ip_flags & IMGPF_IS_64BIT_ADDR) == IMGPF_IS_64BIT_ADDR); + result->is_64bit_data = ((imgp->ip_flags & IMGPF_IS_64BIT_DATA) == IMGPF_IS_64BIT_DATA); +#if defined(HAS_APPLE_PAC) + pmap_flags |= (imgp->ip_flags & IMGPF_NOJOP) ? PMAP_CREATE_DISABLE_JOP : 0; +#endif /* defined(HAS_APPLE_PAC) */ + pmap_flags |= result->is_64bit_addr ? PMAP_CREATE_64BIT : 0; + + task_t ledger_task; + if (imgp->ip_new_thread) { + ledger_task = get_threadtask(imgp->ip_new_thread); + } else { + ledger_task = task; + } + pmap = pmap_create_options(get_task_ledger(ledger_task), + (vm_map_size_t) 0, + pmap_flags); + if (pmap == NULL) { + return LOAD_RESOURCE; + } + map = vm_map_create(pmap, + 0, + vm_compute_max_offset(result->is_64bit_addr), + TRUE); + +#if defined(__arm64__) + if (result->is_64bit_addr) { + /* enforce 16KB alignment of VM map entries */ + vm_map_set_page_shift(map, SIXTEENK_PAGE_SHIFT); + } else { + vm_map_set_page_shift(map, page_shift_user32); + } +#elif (__ARM_ARCH_7K__ >= 2) && defined(PLATFORM_WatchOS) + /* enforce 16KB alignment for watch targets with new ABI */ + vm_map_set_page_shift(map, SIXTEENK_PAGE_SHIFT); +#endif /* __arm64__ */ + +#ifndef CONFIG_ENFORCE_SIGNED_CODE + /* This turns off faulting for executable pages, which allows + * to circumvent Code Signing Enforcement. The per process + * flag (CS_ENFORCEMENT) is not set yet, but we can use the + * global flag. */ - if (spawn) { - create_map = TRUE; - old_task = get_threadtask(thread); + if (!cs_process_global_enforcement() && (header->flags & MH_ALLOW_STACK_EXECUTION)) { + vm_map_disable_NX(map); + // TODO: Message Trace or log that this is happening } - - if (create_map) { - pmap = pmap_create((vm_map_size_t) 0, (imgp->ip_flags & IMGPF_IS_64BIT)); - pal_switch_pmap(thread, pmap, imgp->ip_flags & IMGPF_IS_64BIT); - map = vm_map_create(pmap, - 0, - vm_compute_max_offset((imgp->ip_flags & IMGPF_IS_64BIT)), - TRUE); - - } else - map = new_map; - -#ifndef CONFIG_ENFORCE_SIGNED_CODE - /* This turns off faulting for executable pages, which allows to - * circumvent Code Signing Enforcement */ - if ( (header->flags & MH_ALLOW_STACK_EXECUTION) ) - vm_map_disable_NX(map); #endif /* Forcibly disallow execution from data pages on even if the arch * normally permits it. */ - if ((header->flags & MH_NO_HEAP_EXECUTION) && !(imgp->ip_flags & IMGPF_ALLOW_DATA_EXEC)) + if ((header->flags & MH_NO_HEAP_EXECUTION) && !(imgp->ip_flags & IMGPF_ALLOW_DATA_EXEC)) { vm_map_disallow_data_exec(map); - + } + /* - * Compute a random offset for ASLR. + * Compute a random offset for ASLR, and an independent random offset for dyld. */ if (!(imgp->ip_flags & IMGPF_DISABLE_ASLR)) { - aslr_offset = random(); - aslr_offset %= 1 << ((imgp->ip_flags & IMGPF_IS_64BIT) ? 16 : 8); - aslr_offset <<= PAGE_SHIFT; + vm_map_get_max_aslr_slide_section(map, &aslr_section_offset, &aslr_section_size); + aslr_section_offset = (random() % aslr_section_offset) * aslr_section_size; + + aslr_page_offset = random(); + aslr_page_offset %= vm_map_get_max_aslr_slide_pages(map); + aslr_page_offset <<= vm_map_page_shift(map); + + dyld_aslr_page_offset = random(); + dyld_aslr_page_offset %= vm_map_get_max_loader_aslr_slide_pages(map); + dyld_aslr_page_offset <<= vm_map_page_shift(map); + + aslr_page_offset += aslr_section_offset; } - - if (!result) + + if (!result) { result = &myresult; + } *result = load_result_null; + /* + * re-set the bitness on the load result since we cleared the load result above. + */ + result->is_64bit_addr = ((imgp->ip_flags & IMGPF_IS_64BIT_ADDR) == IMGPF_IS_64BIT_ADDR); + result->is_64bit_data = ((imgp->ip_flags & IMGPF_IS_64BIT_DATA) == IMGPF_IS_64BIT_DATA); + lret = parse_machfile(vp, map, thread, header, file_offset, macho_size, - 0, (int64_t)aslr_offset, result); + 0, aslr_page_offset, dyld_aslr_page_offset, result, + NULL, imgp); if (lret != LOAD_SUCCESS) { - if (create_map) { - vm_map_deallocate(map); /* will lose pmap reference too */ - } - return(lret); + vm_map_deallocate(map); /* will lose pmap reference too */ + return lret; + } + +#if __x86_64__ + /* + * On x86, for compatibility, don't enforce the hard page-zero restriction for 32-bit binaries. + */ + if (!result->is_64bit_addr) { + enforce_hard_pagezero = FALSE; + } + + /* + * For processes with IMGPF_HIGH_BITS_ASLR, add a few random high bits + * to the start address for "anywhere" memory allocations. + */ +#define VM_MAP_HIGH_START_BITS_COUNT 8 +#define VM_MAP_HIGH_START_BITS_SHIFT 27 + if (result->is_64bit_addr && + (imgp->ip_flags & IMGPF_HIGH_BITS_ASLR)) { + int random_bits; + vm_map_offset_t high_start; + + random_bits = random(); + random_bits &= (1 << VM_MAP_HIGH_START_BITS_COUNT) - 1; + high_start = (((vm_map_offset_t)random_bits) + << VM_MAP_HIGH_START_BITS_SHIFT); + vm_map_set_high_start(map, high_start); } +#endif /* __x86_64__ */ /* - * For 64-bit users, check for presence of a 4GB page zero - * which will enable the kernel to share the user's address space - * and hence avoid TLB flushes on kernel entry/exit - */ + * Check to see if the page zero is enforced by the map->min_offset. + */ + if (enforce_hard_pagezero && + (vm_map_has_hard_pagezero(map, 0x1000) == FALSE)) { +#if __arm64__ + if (!result->is_64bit_addr && /* not 64-bit address space */ + !(header->flags & MH_PIE) && /* not PIE */ + (vm_map_page_shift(map) != FOURK_PAGE_SHIFT || + PAGE_SHIFT != FOURK_PAGE_SHIFT) && /* page size != 4KB */ + result->has_pagezero && /* has a "soft" page zero */ + fourk_binary_compatibility_unsafe) { + /* + * For backwards compatibility of "4K" apps on + * a 16K system, do not enforce a hard page zero... + */ + } else +#endif /* __arm64__ */ + { + vm_map_deallocate(map); /* will lose pmap reference too */ + return LOAD_BADMACHO; + } + } - if ((imgp->ip_flags & IMGPF_IS_64BIT) && - vm_map_has_4GB_pagezero(map)) - vm_map_set_4GB_pagezero(map); + vm_commit_pagezero_status(map); /* - * Commit to new map. - * - * Swap the new map for the old, which consumes our new map - * reference but each leaves us responsible for the old_map reference. - * That lets us get off the pmap associated with it, and - * then we can release it. + * If this is an exec, then we are going to destroy the old + * task, and it's correct to halt it; if it's spawn, the + * task is not yet running, and it makes no sense. */ + if (in_exec) { + proc_t p = vfs_context_proc(imgp->ip_vfs_context); + /* + * Mark the task as halting and start the other + * threads towards terminating themselves. Then + * make sure any threads waiting for a process + * transition get informed that we are committed to + * this transition, and then finally complete the + * task halting (wait for threads and then cleanup + * task resources). + * + * NOTE: task_start_halt() makes sure that no new + * threads are created in the task during the transition. + * We need to mark the workqueue as exiting before we + * wait for threads to terminate (at the end of which + * we no longer have a prohibition on thread creation). + * + * Finally, clean up any lingering workqueue data structures + * that may have been left behind by the workqueue threads + * as they exited (and then clean up the work queue itself). + */ + kret = task_start_halt(task); + if (kret != KERN_SUCCESS) { + vm_map_deallocate(map); /* will lose pmap reference too */ + return LOAD_FAILURE; + } + proc_transcommit(p, 0); + workq_mark_exiting(p); + task_complete_halt(task); + workq_exit(p); - if (create_map) { /* - * If this is an exec, then we are going to destroy the old - * task, and it's correct to halt it; if it's spawn, the - * task is not yet running, and it makes no sense. + * Roll up accounting info to new task. The roll up is done after + * task_complete_halt to make sure the thread accounting info is + * rolled up to current_task. */ - if (!spawn) { - /* - * Mark the task as halting and start the other - * threads towards terminating themselves. Then - * make sure any threads waiting for a process - * transition get informed that we are committed to - * this transition, and then finally complete the - * task halting (wait for threads and then cleanup - * task resources). - * - * NOTE: task_start_halt() makes sure that no new - * threads are created in the task during the transition. - * We need to mark the workqueue as exiting before we - * wait for threads to terminate (at the end of which - * we no longer have a prohibition on thread creation). - * - * Finally, clean up any lingering workqueue data structures - * that may have been left behind by the workqueue threads - * as they exited (and then clean up the work queue itself). - */ - kret = task_start_halt(task); - if (kret != KERN_SUCCESS) { - return(kret); - } - proc_transcommit(p, 0); - workqueue_mark_exiting(p); - task_complete_halt(task); - workqueue_exit(p); - } - old_map = swap_task_map(old_task, thread, map, !spawn); - vm_map_clear_4GB_pagezero(old_map); - vm_map_deallocate(old_map); - } - return(LOAD_SUCCESS); + task_rollup_accounting_info(get_threadtask(thread), task); + } + *mapp = map; + +#ifdef CONFIG_32BIT_TELEMETRY + if (!result->is_64bit_data) { + /* + * This may not need to be an AST; we merely need to ensure that + * we gather telemetry at the point where all of the information + * that we want has been added to the process. + */ + task_set_32bit_log_flag(get_threadtask(thread)); + act_set_astbsd(thread); + } +#endif /* CONFIG_32BIT_TELEMETRY */ + + return LOAD_SUCCESS; } +int macho_printf = 0; +#define MACHO_PRINTF(args) \ + do { \ + if (macho_printf) { \ + printf args; \ + } \ + } while (0) + /* * The file size of a mach-o file is limited to 32 bits; this is because * this is the limit on the kalloc() of enough bytes for a mach_header and @@ -434,48 +600,65 @@ load_machfile( static load_return_t parse_machfile( - struct vnode *vp, - vm_map_t map, - thread_t thread, - struct mach_header *header, - off_t file_offset, - off_t macho_size, - int depth, - int64_t aslr_offset, - load_result_t *result -) + struct vnode *vp, + vm_map_t map, + thread_t thread, + struct mach_header *header, + off_t file_offset, + off_t macho_size, + int depth, + int64_t aslr_offset, + int64_t dyld_aslr_offset, + load_result_t *result, + load_result_t *binresult, + struct image_params *imgp + ) { - uint32_t ncmds; - struct load_command *lcp; - struct dylinker_command *dlp = 0; - struct uuid_command *uulp = 0; - integer_t dlarchbits = 0; - void * control; - load_return_t ret = LOAD_SUCCESS; - caddr_t addr; - void * kl_addr; - vm_size_t size,kl_size; - size_t offset; - size_t oldoffset; /* for overflow check */ - int pass; - proc_t p = current_proc(); /* XXXX */ - int error; - int resid=0; - size_t mach_header_sz = sizeof(struct mach_header); - boolean_t abi64; - boolean_t got_code_signatures = FALSE; - int64_t slide = 0; + uint32_t ncmds; + struct load_command *lcp; + struct dylinker_command *dlp = 0; + integer_t dlarchbits = 0; + void * control; + load_return_t ret = LOAD_SUCCESS; + void * addr; + vm_size_t alloc_size, cmds_size; + size_t offset; + size_t oldoffset; /* for overflow check */ + int pass; + proc_t p = vfs_context_proc(imgp->ip_vfs_context); + int error; + int resid = 0; + int spawn = (imgp->ip_flags & IMGPF_SPAWN); + int vfexec = (imgp->ip_flags & IMGPF_VFORK_EXEC); + size_t mach_header_sz = sizeof(struct mach_header); + boolean_t abi64; + boolean_t got_code_signatures = FALSE; + boolean_t found_header_segment = FALSE; + boolean_t found_xhdr = FALSE; + boolean_t found_version_cmd = FALSE; + int64_t slide = 0; + boolean_t dyld_no_load_addr = FALSE; + boolean_t is_dyld = FALSE; + vm_map_offset_t effective_page_mask = MAX(PAGE_MASK, vm_map_page_mask(map)); +#if __arm64__ + uint32_t pagezero_end = 0; + uint32_t executable_end = 0; + uint32_t writable_start = 0; + vm_map_size_t effective_page_size; + + effective_page_size = MAX(PAGE_SIZE, vm_map_page_size(map)); +#endif /* __arm64__ */ if (header->magic == MH_MAGIC_64 || header->magic == MH_CIGAM_64) { - mach_header_sz = sizeof(struct mach_header_64); + mach_header_sz = sizeof(struct mach_header_64); } /* * Break infinite recursion */ - if (depth > 6) { - return(LOAD_FAILURE); + if (depth > 1) { + return LOAD_FAILURE; } depth++; @@ -483,38 +666,44 @@ parse_machfile( /* * Check to see if right machine type. */ - if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != cpu_type()) || - !grade_binary(header->cputype, - header->cpusubtype & ~CPU_SUBTYPE_MASK)) - return(LOAD_BADARCH); - + if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != (cpu_type() & ~CPU_ARCH_MASK)) || + !grade_binary(header->cputype, + header->cpusubtype & ~CPU_SUBTYPE_MASK, TRUE)) { + return LOAD_BADARCH; + } + abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64); - + switch (header->filetype) { - - case MH_OBJECT: case MH_EXECUTE: - case MH_PRELOAD: if (depth != 1) { - return (LOAD_FAILURE); + return LOAD_FAILURE; } - break; - - case MH_FVMLIB: - case MH_DYLIB: - if (depth == 1) { - return (LOAD_FAILURE); +#if CONFIG_EMBEDDED + if (header->flags & MH_DYLDLINK) { + /* Check properties of dynamic executables */ + if (!(header->flags & MH_PIE) && pie_required(header->cputype, header->cpusubtype & ~CPU_SUBTYPE_MASK)) { + return LOAD_FAILURE; + } + result->needs_dynlinker = TRUE; + } else { + /* Check properties of static executables (disallowed except for development) */ +#if !(DEVELOPMENT || DEBUG) + return LOAD_FAILURE; +#endif } - break; +#endif /* CONFIG_EMBEDDED */ + break; case MH_DYLINKER: if (depth != 2) { - return (LOAD_FAILURE); + return LOAD_FAILURE; } + is_dyld = TRUE; break; - + default: - return (LOAD_FAILURE); + return LOAD_FAILURE; } /* @@ -522,60 +711,157 @@ parse_machfile( */ control = ubc_getobject(vp, UBC_FLAGS_NONE); - /* - * Map portion that must be accessible directly into - * kernel's map. - */ - if ((off_t)(mach_header_sz + header->sizeofcmds) > macho_size) - return(LOAD_BADMACHO); - - /* - * Round size of Mach-O commands up to page boundry. - */ - size = round_page(mach_header_sz + header->sizeofcmds); - if (size <= 0) - return(LOAD_BADMACHO); + /* ensure header + sizeofcmds falls within the file */ + if (os_add_overflow(mach_header_sz, header->sizeofcmds, &cmds_size) || + (off_t)cmds_size > macho_size || + round_page_overflow(cmds_size, &alloc_size)) { + return LOAD_BADMACHO; + } /* * Map the load commands into kernel memory. */ - addr = 0; - kl_size = size; - kl_addr = kalloc(size); - addr = (caddr_t)kl_addr; - if (addr == NULL) - return(LOAD_NOSPACE); - - error = vn_rdwr(UIO_READ, vp, addr, size, file_offset, - UIO_SYSSPACE, 0, kauth_cred_get(), &resid, p); + addr = kalloc(alloc_size); + if (addr == NULL) { + return LOAD_NOSPACE; + } + + error = vn_rdwr(UIO_READ, vp, addr, alloc_size, file_offset, + UIO_SYSSPACE, 0, vfs_context_ucred(imgp->ip_vfs_context), &resid, p); if (error) { - if (kl_addr ) - kfree(kl_addr, kl_size); - return(LOAD_IOERROR); + kfree(addr, alloc_size); + return LOAD_IOERROR; + } + + if (resid) { + /* We must be able to read in as much as the mach_header indicated */ + kfree(addr, alloc_size); + return LOAD_BADMACHO; } /* * For PIE and dyld, slide everything by the ASLR offset. */ - if ((header->flags & MH_PIE) || (header->filetype == MH_DYLINKER)) { + if ((header->flags & MH_PIE) || is_dyld) { slide = aslr_offset; } /* - * Scan through the commands, processing each one as necessary. + * Scan through the commands, processing each one as necessary. + * We parse in three passes through the headers: + * 0: determine if TEXT and DATA boundary can be page-aligned + * 1: thread state, uuid, code signature + * 2: segments + * 3: dyld, encryption, check entry point */ - for (pass = 1; pass <= 3; pass++) { -#if CONFIG_EMBEDDED + boolean_t slide_realign = FALSE; +#if __arm64__ + if (!abi64) { + slide_realign = TRUE; + } +#endif + + for (pass = 0; pass <= 3; pass++) { + if (pass == 0 && !slide_realign && !is_dyld) { + /* if we dont need to realign the slide or determine dyld's load + * address, pass 0 can be skipped */ + continue; + } else if (pass == 1) { +#if __arm64__ + boolean_t is_pie; + int64_t adjust; + + is_pie = ((header->flags & MH_PIE) != 0); + if (pagezero_end != 0 && + pagezero_end < effective_page_size) { + /* need at least 1 page for PAGEZERO */ + adjust = effective_page_size; + MACHO_PRINTF(("pagezero boundary at " + "0x%llx; adjust slide from " + "0x%llx to 0x%llx%s\n", + (uint64_t) pagezero_end, + slide, + slide + adjust, + (is_pie + ? "" + : " BUT NO PIE ****** :-("))); + if (is_pie) { + slide += adjust; + pagezero_end += adjust; + executable_end += adjust; + writable_start += adjust; + } + } + if (pagezero_end != 0) { + result->has_pagezero = TRUE; + } + if (executable_end == writable_start && + (executable_end & effective_page_mask) != 0 && + (executable_end & FOURK_PAGE_MASK) == 0) { + /* + * The TEXT/DATA boundary is 4K-aligned but + * not page-aligned. Adjust the slide to make + * it page-aligned and avoid having a page + * with both write and execute permissions. + */ + adjust = + (effective_page_size - + (executable_end & effective_page_mask)); + MACHO_PRINTF(("page-unaligned X-W boundary at " + "0x%llx; adjust slide from " + "0x%llx to 0x%llx%s\n", + (uint64_t) executable_end, + slide, + slide + adjust, + (is_pie + ? "" + : " BUT NO PIE ****** :-("))); + if (is_pie) { + slide += adjust; + } + } +#endif /* __arm64__ */ + + if (dyld_no_load_addr && binresult) { + /* + * The dyld Mach-O does not specify a load address. Try to locate + * it right after the main binary. If binresult == NULL, load + * directly to the given slide. + */ + slide = vm_map_round_page(slide + binresult->max_vm_addr, effective_page_mask); + } + } + /* * Check that the entry point is contained in an executable segments - */ - if ((pass == 3) && (result->validentry == 0)) { - thread_state_initialize(thread); - ret = LOAD_FAILURE; + */ + if (pass == 3) { + if (depth == 1 && imgp && (imgp->ip_flags & IMGPF_DRIVER)) { + /* Driver binaries must have driverkit platform */ + if (result->ip_platform == PLATFORM_DRIVERKIT) { + /* Driver binaries have no entry point */ + ret = setup_driver_main(thread, slide, result); + } else { + ret = LOAD_FAILURE; + } + } else if (!result->using_lcmain && result->validentry == 0) { + ret = LOAD_FAILURE; + } + if (ret != KERN_SUCCESS) { + thread_state_initialize(thread); + break; + } + } + + /* + * Check that some segment maps the start of the mach-o file, which is + * needed by the dynamic loader to read the mach headers, etc. + */ + if ((pass == 3) && (found_header_segment == FALSE)) { + ret = LOAD_BADMACHO; break; } -#endif /* * Loop through each of the load_commands indicated by the @@ -587,12 +873,17 @@ parse_machfile( ncmds = header->ncmds; while (ncmds--) { + /* ensure enough space for a minimal load command */ + if (offset + sizeof(struct load_command) > cmds_size) { + ret = LOAD_BADMACHO; + break; + } + /* * Get a pointer to the command. */ lcp = (struct load_command *)(addr + offset); oldoffset = offset; - offset += lcp->cmdsize; /* * Perform prevalidation of the struct load_command @@ -602,9 +893,9 @@ parse_machfile( * straddle or exist past the reserved section at the * start of the image. */ - if (oldoffset > offset || + if (os_add_overflow(offset, lcp->cmdsize, &offset) || lcp->cmdsize < sizeof(struct load_command) || - offset > header->sizeofcmds + mach_header_sz) { + offset > cmds_size) { ret = LOAD_BADMACHO; break; } @@ -612,34 +903,176 @@ parse_machfile( /* * Act on struct load_command's for which kernel * intervention is required. + * Note that each load command implementation is expected to validate + * that lcp->cmdsize is large enough to fit its specific struct type + * before dereferencing fields not covered by struct load_command. */ - switch(lcp->cmd) { - case LC_SEGMENT: - case LC_SEGMENT_64: - if (pass != 2) + switch (lcp->cmd) { + case LC_SEGMENT: { + struct segment_command *scp = (struct segment_command *) lcp; + if (scp->cmdsize < sizeof(*scp)) { + ret = LOAD_BADMACHO; + break; + } + if (pass == 0) { + if (is_dyld && scp->vmaddr == 0 && scp->fileoff == 0) { + dyld_no_load_addr = TRUE; + if (!slide_realign) { + /* got what we need, bail early on pass 0 */ + continue; + } + } + +#if __arm64__ + assert(!abi64); + + if (scp->initprot == 0 && scp->maxprot == 0 && scp->vmaddr == 0) { + /* PAGEZERO */ + if (os_add3_overflow(scp->vmaddr, scp->vmsize, slide, &pagezero_end)) { + ret = LOAD_BADMACHO; + break; + } + } + if (scp->initprot & VM_PROT_EXECUTE) { + /* TEXT */ + if (os_add3_overflow(scp->vmaddr, scp->vmsize, slide, &executable_end)) { + ret = LOAD_BADMACHO; + break; + } + } + if (scp->initprot & VM_PROT_WRITE) { + /* DATA */ + if (os_add_overflow(scp->vmaddr, slide, &writable_start)) { + ret = LOAD_BADMACHO; + break; + } + } +#endif /* __arm64__ */ + break; + } + + if (pass == 1 && !strncmp(scp->segname, "__XHDR", sizeof(scp->segname))) { + found_xhdr = TRUE; + } + + if (pass != 2) { + break; + } + + if (abi64) { + /* + * Having an LC_SEGMENT command for the + * wrong ABI is invalid + */ + ret = LOAD_BADMACHO; + break; + } + + ret = load_segment(lcp, + header->filetype, + control, + file_offset, + macho_size, + vp, + map, + slide, + result); + if (ret == LOAD_SUCCESS && scp->fileoff == 0 && scp->filesize > 0) { + /* Enforce a single segment mapping offset zero, with R+X + * protection. */ + if (found_header_segment || + ((scp->initprot & (VM_PROT_READ | VM_PROT_EXECUTE)) != (VM_PROT_READ | VM_PROT_EXECUTE))) { + ret = LOAD_BADMACHO; + break; + } + found_header_segment = TRUE; + } + + break; + } + case LC_SEGMENT_64: { + struct segment_command_64 *scp64 = (struct segment_command_64 *) lcp; + if (scp64->cmdsize < sizeof(*scp64)) { + ret = LOAD_BADMACHO; + break; + } + if (pass == 0) { + if (is_dyld && scp64->vmaddr == 0 && scp64->fileoff == 0) { + dyld_no_load_addr = TRUE; + if (!slide_realign) { + /* got what we need, bail early on pass 0 */ + continue; + } + } + } + + if (pass == 1 && !strncmp(scp64->segname, "__XHDR", sizeof(scp64->segname))) { + found_xhdr = TRUE; + } + + if (pass != 2) { + break; + } + + if (!abi64) { + /* + * Having an LC_SEGMENT_64 command for the + * wrong ABI is invalid + */ + ret = LOAD_BADMACHO; break; + } + ret = load_segment(lcp, - header->filetype, - control, - file_offset, - macho_size, - vp, - map, - slide, - result); + header->filetype, + control, + file_offset, + macho_size, + vp, + map, + slide, + result); + + if (ret == LOAD_SUCCESS && scp64->fileoff == 0 && scp64->filesize > 0) { + /* Enforce a single segment mapping offset zero, with R+X + * protection. */ + if (found_header_segment || + ((scp64->initprot & (VM_PROT_READ | VM_PROT_EXECUTE)) != (VM_PROT_READ | VM_PROT_EXECUTE))) { + ret = LOAD_BADMACHO; + break; + } + found_header_segment = TRUE; + } + break; + } case LC_UNIXTHREAD: - if (pass != 1) + if (pass != 1) { break; + } ret = load_unixthread( - (struct thread_command *) lcp, - thread, - slide, - result); + (struct thread_command *) lcp, + thread, + slide, + result); + break; + case LC_MAIN: + if (pass != 1) { + break; + } + if (depth != 1) { + break; + } + ret = load_main( + (struct entry_point_command *) lcp, + thread, + slide, + result); break; case LC_LOAD_DYLINKER: - if (pass != 3) + if (pass != 3) { break; + } if ((depth == 1) && (dlp == 0)) { dlp = (struct dylinker_command *)lcp; dlarchbits = (header->cputype & CPU_ARCH_MASK); @@ -649,489 +1082,1514 @@ parse_machfile( break; case LC_UUID: if (pass == 1 && depth == 1) { - uulp = (struct uuid_command *)lcp; - memcpy(&result->uuid[0], &uulp->uuid[0], sizeof(result->uuid)); + ret = load_uuid((struct uuid_command *) lcp, + (char *)addr + cmds_size, + result); } break; case LC_CODE_SIGNATURE: /* CODE SIGNING */ - if (pass != 1) + if (pass != 1) { break; + } /* pager -> uip -> - load signatures & store in uip - set VM object "signed_pages" - */ + * load signatures & store in uip + * set VM object "signed_pages" + */ ret = load_code_signature( (struct linkedit_data_command *) lcp, vp, file_offset, macho_size, header->cputype, - (depth == 1) ? result : NULL); + result, + imgp); if (ret != LOAD_SUCCESS) { printf("proc %d: load code signature error %d " - "for file \"%s\"\n", - p->p_pid, ret, vp->v_name); - ret = LOAD_SUCCESS; /* ignore error */ + "for file \"%s\"\n", + p->p_pid, ret, vp->v_name); + /* + * Allow injections to be ignored on devices w/o enforcement enabled + */ + if (!cs_process_global_enforcement()) { + ret = LOAD_SUCCESS; /* ignore error */ + } } else { got_code_signatures = TRUE; } + + if (got_code_signatures) { + unsigned tainted = CS_VALIDATE_TAINTED; + boolean_t valid = FALSE; + vm_size_t off = 0; + + + if (cs_debug > 10) { + printf("validating initial pages of %s\n", vp->v_name); + } + + while (off < alloc_size && ret == LOAD_SUCCESS) { + tainted = CS_VALIDATE_TAINTED; + + valid = cs_validate_range(vp, + NULL, + file_offset + off, + addr + off, + PAGE_SIZE, + &tainted); + if (!valid || (tainted & CS_VALIDATE_TAINTED)) { + if (cs_debug) { + printf("CODE SIGNING: %s[%d]: invalid initial page at offset %lld validated:%d tainted:%d csflags:0x%x\n", + vp->v_name, p->p_pid, (long long)(file_offset + off), valid, tainted, result->csflags); + } + if (cs_process_global_enforcement() || + (result->csflags & (CS_HARD | CS_KILL | CS_ENFORCEMENT))) { + ret = LOAD_FAILURE; + } + result->csflags &= ~CS_VALID; + } + off += PAGE_SIZE; + } + } + break; #if CONFIG_CODE_DECRYPTION case LC_ENCRYPTION_INFO: - if (pass != 3) + case LC_ENCRYPTION_INFO_64: + if (pass != 3) { break; + } ret = set_code_unprotect( (struct encryption_info_command *) lcp, - addr, map, vp); + addr, map, slide, vp, file_offset, + header->cputype, header->cpusubtype); if (ret != LOAD_SUCCESS) { + os_reason_t load_failure_reason = OS_REASON_NULL; printf("proc %d: set_code_unprotect() error %d " - "for file \"%s\"\n", - p->p_pid, ret, vp->v_name); - /* Don't let the app run if it's + "for file \"%s\"\n", + p->p_pid, ret, vp->v_name); + /* + * Don't let the app run if it's * encrypted but we failed to set up the - * decrypter */ - psignal(p, SIGKILL); + * decrypter. If the keys are missing it will + * return LOAD_DECRYPTFAIL. + */ + if (ret == LOAD_DECRYPTFAIL) { + /* failed to load due to missing FP keys */ + proc_lock(p); + p->p_lflag |= P_LTERM_DECRYPTFAIL; + proc_unlock(p); + + KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE, + p->p_pid, OS_REASON_EXEC, EXEC_EXIT_REASON_FAIRPLAY_DECRYPT, 0, 0); + load_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_FAIRPLAY_DECRYPT); + } else { + KERNEL_DEBUG_CONSTANT(BSDDBG_CODE(DBG_BSD_PROC, BSD_PROC_EXITREASON_CREATE) | DBG_FUNC_NONE, + p->p_pid, OS_REASON_EXEC, EXEC_EXIT_REASON_DECRYPT, 0, 0); + load_failure_reason = os_reason_create(OS_REASON_EXEC, EXEC_EXIT_REASON_DECRYPT); + } + + /* + * Don't signal the process if it was forked and in a partially constructed + * state as part of a spawn -- it will just be torn down when the exec fails. + */ + if (!spawn) { + assert(load_failure_reason != OS_REASON_NULL); + if (vfexec) { + psignal_vfork_with_reason(p, get_threadtask(imgp->ip_new_thread), imgp->ip_new_thread, SIGKILL, load_failure_reason); + load_failure_reason = OS_REASON_NULL; + } else { + psignal_with_reason(p, SIGKILL, load_failure_reason); + load_failure_reason = OS_REASON_NULL; + } + } else { + os_reason_free(load_failure_reason); + load_failure_reason = OS_REASON_NULL; + } } break; #endif + case LC_VERSION_MIN_IPHONEOS: + case LC_VERSION_MIN_MACOSX: + case LC_VERSION_MIN_WATCHOS: + case LC_VERSION_MIN_TVOS: { + struct version_min_command *vmc; + + if (depth != 1 || pass != 1) { + break; + } + vmc = (struct version_min_command *) lcp; + ret = load_version(vmc, &found_version_cmd, result); + break; + } + case LC_BUILD_VERSION: { + if (depth != 1 || pass != 1) { + break; + } + struct build_version_command* bvc = (struct build_version_command*)lcp; + if (bvc->cmdsize < sizeof(*bvc)) { + ret = LOAD_BADMACHO; + break; + } + if (found_version_cmd == TRUE) { + ret = LOAD_BADMACHO; + break; + } + result->ip_platform = bvc->platform; + found_version_cmd = TRUE; + break; + } default: /* Other commands are ignored by the kernel */ ret = LOAD_SUCCESS; break; } - if (ret != LOAD_SUCCESS) + if (ret != LOAD_SUCCESS) { break; + } } - if (ret != LOAD_SUCCESS) + if (ret != LOAD_SUCCESS) { break; - } - if (ret == LOAD_SUCCESS) { - if (! got_code_signatures) { - struct cs_blob *blob; - /* no embedded signatures: look for detached ones */ - blob = ubc_cs_blob_get(vp, -1, file_offset); - if (blob != NULL) { - /* get flags to be applied to the process */ - result->csflags |= blob->csb_flags; - } - } - - if (dlp != 0) { - /* load the dylinker, and always slide it by the ASLR - * offset regardless of PIE */ - ret = load_dylinker(dlp, dlarchbits, map, thread, depth, aslr_offset, result); - } - - if(depth == 1) { - if (result->thread_count == 0) { - ret = LOAD_FAILURE; } - } } - if (kl_addr ) - kfree(kl_addr, kl_size); - - return(ret); -} - -#if CONFIG_CODE_DECRYPTION - -#define APPLE_UNPROTECTED_HEADER_SIZE (3 * PAGE_SIZE_64) + if (ret == LOAD_SUCCESS) { + if (!got_code_signatures && cs_process_global_enforcement()) { + ret = LOAD_FAILURE; + } -static load_return_t -unprotect_segment( - uint64_t file_off, - uint64_t file_size, - struct vnode *vp, - off_t macho_offset, - vm_map_t map, - vm_map_offset_t map_addr, - vm_map_size_t map_size) -{ - kern_return_t kr; + /* Make sure if we need dyld, we got it */ + if (result->needs_dynlinker && !dlp) { + ret = LOAD_FAILURE; + } - /* - * The first APPLE_UNPROTECTED_HEADER_SIZE bytes (from offset 0 of - * this part of a Universal binary) are not protected... - * The rest needs to be "transformed". - */ - if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE && - file_off + file_size <= APPLE_UNPROTECTED_HEADER_SIZE) { - /* it's all unprotected, nothing to do... */ - kr = KERN_SUCCESS; - } else { - if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE) { + if ((ret == LOAD_SUCCESS) && (dlp != 0)) { /* - * We start mapping in the unprotected area. - * Skip the unprotected part... + * load the dylinker, and slide it by the independent DYLD ASLR + * offset regardless of the PIE-ness of the main binary. */ - vm_map_offset_t delta; + ret = load_dylinker(dlp, dlarchbits, map, thread, depth, + dyld_aslr_offset, result, imgp); + } - delta = APPLE_UNPROTECTED_HEADER_SIZE; - delta -= file_off; - map_addr += delta; - map_size -= delta; + if ((ret == LOAD_SUCCESS) && (depth == 1)) { + if (result->thread_count == 0) { + ret = LOAD_FAILURE; + } +#if CONFIG_ENFORCE_SIGNED_CODE + if (result->needs_dynlinker && !(result->csflags & CS_DYLD_PLATFORM)) { + ret = LOAD_FAILURE; + } +#endif } - /* ... transform the rest of the mapping. */ - struct pager_crypt_info crypt_info; - crypt_info.page_decrypt = dsmos_page_transform; - crypt_info.crypt_ops = NULL; - crypt_info.crypt_end = NULL; -#pragma unused(vp, macho_offset) - crypt_info.crypt_ops = (void *)0x2e69cf40; - kr = vm_map_apple_protected(map, - map_addr, - map_addr + map_size, - &crypt_info); } - if (kr != KERN_SUCCESS) { - return LOAD_FAILURE; + if (ret == LOAD_BADMACHO && found_xhdr) { + ret = LOAD_BADMACHO_UPX; } - return LOAD_SUCCESS; + + kfree(addr, alloc_size); + + return ret; } -#else /* CONFIG_CODE_DECRYPTION */ -static load_return_t -unprotect_segment( - __unused uint64_t file_off, - __unused uint64_t file_size, - __unused struct vnode *vp, - __unused off_t macho_offset, - __unused vm_map_t map, - __unused vm_map_offset_t map_addr, - __unused vm_map_size_t map_size) + +load_return_t +validate_potential_simulator_binary( + cpu_type_t exectype __unused, + struct image_params *imgp __unused, + off_t file_offset __unused, + off_t macho_size __unused) { +#if __x86_64__ + /* Allow 32 bit exec only for simulator binaries */ + if (bootarg_no32exec && imgp != NULL && exectype == CPU_TYPE_X86) { + if (imgp->ip_simulator_binary == IMGPF_SB_DEFAULT) { + boolean_t simulator_binary = check_if_simulator_binary(imgp, file_offset, macho_size); + imgp->ip_simulator_binary = simulator_binary ? IMGPF_SB_TRUE : IMGPF_SB_FALSE; + } + + if (imgp->ip_simulator_binary != IMGPF_SB_TRUE) { + return LOAD_BADARCH; + } + } +#endif return LOAD_SUCCESS; } -#endif /* CONFIG_CODE_DECRYPTION */ -static -load_return_t -load_segment( - struct load_command *lcp, - uint32_t filetype, - void * control, - off_t pager_offset, - off_t macho_size, - struct vnode *vp, - vm_map_t map, - int64_t slide, - load_result_t *result -) +#if __x86_64__ +static boolean_t +check_if_simulator_binary( + struct image_params *imgp, + off_t file_offset, + off_t macho_size) { - struct segment_command_64 segment_command, *scp; - kern_return_t ret; - mach_vm_offset_t map_addr, map_offset; - mach_vm_size_t map_size, seg_size, delta_size; - vm_prot_t initprot; - vm_prot_t maxprot; - size_t segment_command_size, total_section_size, - single_section_size; - - if (LC_SEGMENT_64 == lcp->cmd) { - segment_command_size = sizeof(struct segment_command_64); - single_section_size = sizeof(struct section_64); + struct mach_header *header; + char *ip_vdata = NULL; + kauth_cred_t cred = NULL; + uint32_t ncmds; + struct load_command *lcp; + boolean_t simulator_binary = FALSE; + void * addr = NULL; + vm_size_t alloc_size, cmds_size; + size_t offset; + proc_t p = current_proc(); /* XXXX */ + int error; + int resid = 0; + size_t mach_header_sz = sizeof(struct mach_header); + + + cred = kauth_cred_proc_ref(p); + + /* Allocate page to copyin mach header */ + ip_vdata = kalloc(PAGE_SIZE); + if (ip_vdata == NULL) { + goto bad; + } + + /* Read the Mach-O header */ + error = vn_rdwr(UIO_READ, imgp->ip_vp, ip_vdata, + PAGE_SIZE, file_offset, + UIO_SYSSPACE, (IO_UNIT | IO_NODELOCKED), + cred, &resid, p); + if (error) { + goto bad; + } + + header = (struct mach_header *)ip_vdata; + + if (header->magic == MH_MAGIC_64 || + header->magic == MH_CIGAM_64) { + mach_header_sz = sizeof(struct mach_header_64); + } + + /* ensure header + sizeofcmds falls within the file */ + if (os_add_overflow(mach_header_sz, header->sizeofcmds, &cmds_size) || + (off_t)cmds_size > macho_size || + round_page_overflow(cmds_size, &alloc_size)) { + goto bad; + } + + /* + * Map the load commands into kernel memory. + */ + addr = kalloc(alloc_size); + if (addr == NULL) { + goto bad; + } + + error = vn_rdwr(UIO_READ, imgp->ip_vp, addr, alloc_size, file_offset, + UIO_SYSSPACE, IO_NODELOCKED, cred, &resid, p); + if (error) { + goto bad; + } + + if (resid) { + /* We must be able to read in as much as the mach_header indicated */ + goto bad; + } + + /* + * Loop through each of the load_commands indicated by the + * Mach-O header; if an absurd value is provided, we just + * run off the end of the reserved section by incrementing + * the offset too far, so we are implicitly fail-safe. + */ + offset = mach_header_sz; + ncmds = header->ncmds; + + while (ncmds--) { + /* ensure enough space for a minimal load command */ + if (offset + sizeof(struct load_command) > cmds_size) { + break; + } + + /* + * Get a pointer to the command. + */ + lcp = (struct load_command *)(addr + offset); + + /* + * Perform prevalidation of the struct load_command + * before we attempt to use its contents. Invalid + * values are ones which result in an overflow, or + * which can not possibly be valid commands, or which + * straddle or exist past the reserved section at the + * start of the image. + */ + if (os_add_overflow(offset, lcp->cmdsize, &offset) || + lcp->cmdsize < sizeof(struct load_command) || + offset > cmds_size) { + break; + } + + /* Check if its a simulator binary. */ + switch (lcp->cmd) { + case LC_VERSION_MIN_WATCHOS: + simulator_binary = TRUE; + break; + + case LC_BUILD_VERSION: { + struct build_version_command *bvc; + + bvc = (struct build_version_command *) lcp; + if (bvc->cmdsize < sizeof(*bvc)) { + /* unsafe to use this command struct if cmdsize + * validated above is too small for it to fit */ + break; + } + if (bvc->platform == PLATFORM_IOSSIMULATOR || + bvc->platform == PLATFORM_WATCHOSSIMULATOR) { + simulator_binary = TRUE; + } + + break; + } + + case LC_VERSION_MIN_IPHONEOS: { + simulator_binary = TRUE; + break; + } + + default: + /* ignore other load commands */ + break; + } + + if (simulator_binary == TRUE) { + break; + } + } + +bad: + if (ip_vdata) { + kfree(ip_vdata, PAGE_SIZE); + } + + if (cred) { + kauth_cred_unref(&cred); + } + + if (addr) { + kfree(addr, alloc_size); + } + + return simulator_binary; +} +#endif /* __x86_64__ */ + +#if CONFIG_CODE_DECRYPTION + +#define APPLE_UNPROTECTED_HEADER_SIZE (3 * 4096) + +static load_return_t +unprotect_dsmos_segment( + uint64_t file_off, + uint64_t file_size, + struct vnode *vp, + off_t macho_offset, + vm_map_t map, + vm_map_offset_t map_addr, + vm_map_size_t map_size) +{ + kern_return_t kr; + + /* + * The first APPLE_UNPROTECTED_HEADER_SIZE bytes (from offset 0 of + * this part of a Universal binary) are not protected... + * The rest needs to be "transformed". + */ + if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE && + file_off + file_size <= APPLE_UNPROTECTED_HEADER_SIZE) { + /* it's all unprotected, nothing to do... */ + kr = KERN_SUCCESS; + } else { + if (file_off <= APPLE_UNPROTECTED_HEADER_SIZE) { + /* + * We start mapping in the unprotected area. + * Skip the unprotected part... + */ + vm_map_offset_t delta; + + delta = APPLE_UNPROTECTED_HEADER_SIZE; + delta -= file_off; + map_addr += delta; + map_size -= delta; + } + /* ... transform the rest of the mapping. */ + struct pager_crypt_info crypt_info; + crypt_info.page_decrypt = dsmos_page_transform; + crypt_info.crypt_ops = NULL; + crypt_info.crypt_end = NULL; +#pragma unused(vp, macho_offset) + crypt_info.crypt_ops = (void *)0x2e69cf40; + vm_map_offset_t crypto_backing_offset; + crypto_backing_offset = -1; /* i.e. use map entry's offset */ +#if VM_MAP_DEBUG_APPLE_PROTECT + if (vm_map_debug_apple_protect) { + struct proc *p; + p = current_proc(); + printf("APPLE_PROTECT: %d[%s] map %p " + "[0x%llx:0x%llx] %s(%s)\n", + p->p_pid, p->p_comm, map, + (uint64_t) map_addr, + (uint64_t) (map_addr + map_size), + __FUNCTION__, vp->v_name); + } +#endif /* VM_MAP_DEBUG_APPLE_PROTECT */ + + /* The DSMOS pager can only be used by apple signed code */ + struct cs_blob * blob = csvnode_get_blob(vp, file_off); + if (blob == NULL || !blob->csb_platform_binary || blob->csb_platform_path) { + return LOAD_FAILURE; + } + + kr = vm_map_apple_protected(map, + map_addr, + map_addr + map_size, + crypto_backing_offset, + &crypt_info); + } + + if (kr != KERN_SUCCESS) { + return LOAD_FAILURE; + } + return LOAD_SUCCESS; +} +#else /* CONFIG_CODE_DECRYPTION */ +static load_return_t +unprotect_dsmos_segment( + __unused uint64_t file_off, + __unused uint64_t file_size, + __unused struct vnode *vp, + __unused off_t macho_offset, + __unused vm_map_t map, + __unused vm_map_offset_t map_addr, + __unused vm_map_size_t map_size) +{ + return LOAD_SUCCESS; +} +#endif /* CONFIG_CODE_DECRYPTION */ + + +/* + * map_segment: + * Maps a Mach-O segment, taking care of mis-alignment (wrt the system + * page size) issues. + * + * The mapping might result in 1, 2 or 3 map entries: + * 1. for the first page, which could be overlap with the previous + * mapping, + * 2. for the center (if applicable), + * 3. for the last page, which could overlap with the next mapping. + * + * For each of those map entries, we might have to interpose a + * "fourk_pager" to deal with mis-alignment wrt the system page size, + * either in the mapping address and/or size or the file offset and/or + * size. + * The "fourk_pager" itself would be mapped with proper alignment + * wrt the system page size and would then be populated with the + * information about the intended mapping, with a "4KB" granularity. + */ +static kern_return_t +map_segment( + vm_map_t map, + vm_map_offset_t vm_start, + vm_map_offset_t vm_end, + memory_object_control_t control, + vm_map_offset_t file_start, + vm_map_offset_t file_end, + vm_prot_t initprot, + vm_prot_t maxprot, + load_result_t *result) +{ + vm_map_offset_t cur_offset, cur_start, cur_end; + kern_return_t ret; + vm_map_offset_t effective_page_mask; + vm_map_kernel_flags_t vmk_flags, cur_vmk_flags; + + if (vm_end < vm_start || + file_end < file_start) { + return LOAD_BADMACHO; + } + if (vm_end == vm_start || + file_end == file_start) { + /* nothing to map... */ + return LOAD_SUCCESS; + } + + effective_page_mask = MAX(PAGE_MASK, vm_map_page_mask(map)); + + vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + if (vm_map_page_aligned(vm_start, effective_page_mask) && + vm_map_page_aligned(vm_end, effective_page_mask) && + vm_map_page_aligned(file_start, effective_page_mask) && + vm_map_page_aligned(file_end, effective_page_mask)) { + /* all page-aligned and map-aligned: proceed */ + } else { +#if __arm64__ + /* use an intermediate "4K" pager */ + vmk_flags.vmkf_fourk = TRUE; +#else /* __arm64__ */ + panic("map_segment: unexpected mis-alignment " + "vm[0x%llx:0x%llx] file[0x%llx:0x%llx]\n", + (uint64_t) vm_start, + (uint64_t) vm_end, + (uint64_t) file_start, + (uint64_t) file_end); +#endif /* __arm64__ */ + } + + cur_offset = 0; + cur_start = vm_start; + cur_end = vm_start; +#if __arm64__ + if (!vm_map_page_aligned(vm_start, effective_page_mask)) { + /* one 4K pager for the 1st page */ + cur_end = vm_map_round_page(cur_start, effective_page_mask); + if (cur_end > vm_end) { + cur_end = vm_start + (file_end - file_start); + } + if (control != MEMORY_OBJECT_CONTROL_NULL) { + /* no copy-on-read for mapped binaries */ + vmk_flags.vmkf_no_copy_on_read = 1; + ret = vm_map_enter_mem_object_control( + map, + &cur_start, + cur_end - cur_start, + (mach_vm_offset_t)0, + VM_FLAGS_FIXED, + vmk_flags, + VM_KERN_MEMORY_NONE, + control, + file_start + cur_offset, + TRUE, /* copy */ + initprot, maxprot, + VM_INHERIT_DEFAULT); + } else { + ret = vm_map_enter_mem_object( + map, + &cur_start, + cur_end - cur_start, + (mach_vm_offset_t)0, + VM_FLAGS_FIXED, + vmk_flags, + VM_KERN_MEMORY_NONE, + IPC_PORT_NULL, + 0, /* offset */ + TRUE, /* copy */ + initprot, maxprot, + VM_INHERIT_DEFAULT); + } + if (ret != KERN_SUCCESS) { + return LOAD_NOSPACE; + } + cur_offset += cur_end - cur_start; + } +#endif /* __arm64__ */ + if (cur_end >= vm_start + (file_end - file_start)) { + /* all mapped: done */ + goto done; + } + if (vm_map_round_page(cur_end, effective_page_mask) >= + vm_map_trunc_page(vm_start + (file_end - file_start), + effective_page_mask)) { + /* no middle */ + } else { + cur_start = cur_end; + if ((vm_start & effective_page_mask) != + (file_start & effective_page_mask)) { + /* one 4K pager for the middle */ + cur_vmk_flags = vmk_flags; + } else { + /* regular mapping for the middle */ + cur_vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + } + +#if CONFIG_EMBEDDED + (void) result; +#else /* CONFIG_EMBEDDED */ + /* + * This process doesn't have its new csflags (from + * the image being loaded) yet, so tell VM to override the + * current process's CS_ENFORCEMENT for this mapping. + */ + if (result->csflags & CS_ENFORCEMENT) { + cur_vmk_flags.vmkf_cs_enforcement = TRUE; + } else { + cur_vmk_flags.vmkf_cs_enforcement = FALSE; + } + cur_vmk_flags.vmkf_cs_enforcement_override = TRUE; +#endif /* CONFIG_EMBEDDED */ + + cur_end = vm_map_trunc_page(vm_start + (file_end - + file_start), + effective_page_mask); + if (control != MEMORY_OBJECT_CONTROL_NULL) { + /* no copy-on-read for mapped binaries */ + cur_vmk_flags.vmkf_no_copy_on_read = 1; + ret = vm_map_enter_mem_object_control( + map, + &cur_start, + cur_end - cur_start, + (mach_vm_offset_t)0, + VM_FLAGS_FIXED, + cur_vmk_flags, + VM_KERN_MEMORY_NONE, + control, + file_start + cur_offset, + TRUE, /* copy */ + initprot, maxprot, + VM_INHERIT_DEFAULT); + } else { + ret = vm_map_enter_mem_object( + map, + &cur_start, + cur_end - cur_start, + (mach_vm_offset_t)0, + VM_FLAGS_FIXED, + cur_vmk_flags, + VM_KERN_MEMORY_NONE, + IPC_PORT_NULL, + 0, /* offset */ + TRUE, /* copy */ + initprot, maxprot, + VM_INHERIT_DEFAULT); + } + if (ret != KERN_SUCCESS) { + return LOAD_NOSPACE; + } + cur_offset += cur_end - cur_start; + } + if (cur_end >= vm_start + (file_end - file_start)) { + /* all mapped: done */ + goto done; + } + cur_start = cur_end; +#if __arm64__ + if (!vm_map_page_aligned(vm_start + (file_end - file_start), + effective_page_mask)) { + /* one 4K pager for the last page */ + cur_end = vm_start + (file_end - file_start); + if (control != MEMORY_OBJECT_CONTROL_NULL) { + /* no copy-on-read for mapped binaries */ + vmk_flags.vmkf_no_copy_on_read = 1; + ret = vm_map_enter_mem_object_control( + map, + &cur_start, + cur_end - cur_start, + (mach_vm_offset_t)0, + VM_FLAGS_FIXED, + vmk_flags, + VM_KERN_MEMORY_NONE, + control, + file_start + cur_offset, + TRUE, /* copy */ + initprot, maxprot, + VM_INHERIT_DEFAULT); + } else { + ret = vm_map_enter_mem_object( + map, + &cur_start, + cur_end - cur_start, + (mach_vm_offset_t)0, + VM_FLAGS_FIXED, + vmk_flags, + VM_KERN_MEMORY_NONE, + IPC_PORT_NULL, + 0, /* offset */ + TRUE, /* copy */ + initprot, maxprot, + VM_INHERIT_DEFAULT); + } + if (ret != KERN_SUCCESS) { + return LOAD_NOSPACE; + } + cur_offset += cur_end - cur_start; + } +#endif /* __arm64__ */ +done: + assert(cur_end >= vm_start + (file_end - file_start)); + return LOAD_SUCCESS; +} + +static +load_return_t +load_segment( + struct load_command *lcp, + uint32_t filetype, + void * control, + off_t pager_offset, + off_t macho_size, + struct vnode *vp, + vm_map_t map, + int64_t slide, + load_result_t *result) +{ + struct segment_command_64 segment_command, *scp; + kern_return_t ret; + vm_map_size_t delta_size; + vm_prot_t initprot; + vm_prot_t maxprot; + size_t segment_command_size, total_section_size, + single_section_size; + vm_map_offset_t file_offset, file_size; + vm_map_offset_t vm_offset, vm_size; + vm_map_offset_t vm_start, vm_end, vm_end_aligned; + vm_map_offset_t file_start, file_end; + kern_return_t kr; + boolean_t verbose; + vm_map_size_t effective_page_size; + vm_map_offset_t effective_page_mask; +#if __arm64__ + vm_map_kernel_flags_t vmk_flags; + boolean_t fourk_align; +#endif /* __arm64__ */ + + effective_page_size = MAX(PAGE_SIZE, vm_map_page_size(map)); + effective_page_mask = MAX(PAGE_MASK, vm_map_page_mask(map)); + + verbose = FALSE; + if (LC_SEGMENT_64 == lcp->cmd) { + segment_command_size = sizeof(struct segment_command_64); + single_section_size = sizeof(struct section_64); +#if __arm64__ + /* 64-bit binary: should already be 16K-aligned */ + fourk_align = FALSE; +#endif /* __arm64__ */ } else { segment_command_size = sizeof(struct segment_command); single_section_size = sizeof(struct section); +#if __arm64__ + /* 32-bit binary: might need 4K-alignment */ + if (effective_page_size != FOURK_PAGE_SIZE) { + /* not using 4K page size: need fourk_pager */ + fourk_align = TRUE; + verbose = TRUE; + } else { + /* using 4K page size: no need for re-alignment */ + fourk_align = FALSE; + } +#endif /* __arm64__ */ + } + if (lcp->cmdsize < segment_command_size) { + return LOAD_BADMACHO; } - if (lcp->cmdsize < segment_command_size) - return (LOAD_BADMACHO); total_section_size = lcp->cmdsize - segment_command_size; - if (LC_SEGMENT_64 == lcp->cmd) + if (LC_SEGMENT_64 == lcp->cmd) { scp = (struct segment_command_64 *)lcp; - else { + } else { scp = &segment_command; widen_segment_command((struct segment_command *)lcp, scp); } - /* - * Make sure what we get from the file is really ours (as specified - * by macho_size). - */ - if (scp->fileoff + scp->filesize < scp->fileoff || - scp->fileoff + scp->filesize > (uint64_t)macho_size) - return (LOAD_BADMACHO); - /* - * Ensure that the number of sections specified would fit - * within the load command size. - */ - if (total_section_size / single_section_size < scp->nsects) - return (LOAD_BADMACHO); - /* - * Make sure the segment is page-aligned in the file. - */ - if ((scp->fileoff & PAGE_MASK_64) != 0) - return (LOAD_BADMACHO); + if (verbose) { + MACHO_PRINTF(("+++ load_segment %s " + "vm[0x%llx:0x%llx] file[0x%llx:0x%llx] " + "prot %d/%d flags 0x%x\n", + scp->segname, + (uint64_t)(slide + scp->vmaddr), + (uint64_t)(slide + scp->vmaddr + scp->vmsize), + pager_offset + scp->fileoff, + pager_offset + scp->fileoff + scp->filesize, + scp->initprot, + scp->maxprot, + scp->flags)); + } + + /* + * Make sure what we get from the file is really ours (as specified + * by macho_size). + */ + if (scp->fileoff + scp->filesize < scp->fileoff || + scp->fileoff + scp->filesize > (uint64_t)macho_size) { + return LOAD_BADMACHO; + } + /* + * Ensure that the number of sections specified would fit + * within the load command size. + */ + if (total_section_size / single_section_size < scp->nsects) { + return LOAD_BADMACHO; + } + /* + * Make sure the segment is page-aligned in the file. + */ + file_offset = pager_offset + scp->fileoff; /* limited to 32 bits */ + file_size = scp->filesize; +#if __arm64__ + if (fourk_align) { + if ((file_offset & FOURK_PAGE_MASK) != 0) { + /* + * we can't mmap() it if it's not at least 4KB-aligned + * in the file + */ + return LOAD_BADMACHO; + } + } else +#endif /* __arm64__ */ + if ((file_offset & PAGE_MASK_64) != 0 || + /* we can't mmap() it if it's not page-aligned in the file */ + (file_offset & vm_map_page_mask(map)) != 0) { + /* + * The 1st test would have failed if the system's page size + * was what this process believe is the page size, so let's + * fail here too for the sake of consistency. + */ + return LOAD_BADMACHO; + } + + /* + * If we have a code signature attached for this slice + * require that the segments are within the signed part + * of the file. + */ + if (result->cs_end_offset && + result->cs_end_offset < (off_t)scp->fileoff && + result->cs_end_offset - scp->fileoff < scp->filesize) { + if (cs_debug) { + printf("section outside code signature\n"); + } + return LOAD_BADMACHO; + } + + if (os_add_overflow(scp->vmaddr, slide, &vm_offset)) { + if (cs_debug) { + printf("vmaddr too large\n"); + } + return LOAD_BADMACHO; + } + + vm_size = scp->vmsize; + + if (vm_size == 0) { + return LOAD_SUCCESS; + } + if (scp->vmaddr == 0 && + file_size == 0 && + vm_size != 0 && + (scp->initprot & VM_PROT_ALL) == VM_PROT_NONE && + (scp->maxprot & VM_PROT_ALL) == VM_PROT_NONE) { + /* + * For PIE, extend page zero rather than moving it. Extending + * page zero keeps early allocations from falling predictably + * between the end of page zero and the beginning of the first + * slid segment. + */ + /* + * This is a "page zero" segment: it starts at address 0, + * is not mapped from the binary file and is not accessible. + * User-space should never be able to access that memory, so + * make it completely off limits by raising the VM map's + * minimum offset. + */ + vm_end = vm_offset + vm_size; + if (vm_end < vm_offset) { + return LOAD_BADMACHO; + } + if (verbose) { + MACHO_PRINTF(("++++++ load_segment: " + "page_zero up to 0x%llx\n", + (uint64_t) vm_end)); + } +#if __arm64__ + if (fourk_align) { + /* raise min_offset as much as page-alignment allows */ + vm_end_aligned = vm_map_trunc_page(vm_end, + effective_page_mask); + } else +#endif /* __arm64__ */ + { + vm_end = vm_map_round_page(vm_end, + PAGE_MASK_64); + vm_end_aligned = vm_end; + } + ret = vm_map_raise_min_offset(map, + vm_end_aligned); +#if __arm64__ + if (ret == 0 && + vm_end > vm_end_aligned) { + /* use fourk_pager to map the rest of pagezero */ + assert(fourk_align); + vmk_flags = VM_MAP_KERNEL_FLAGS_NONE; + vmk_flags.vmkf_fourk = TRUE; + ret = vm_map_enter_mem_object( + map, + &vm_end_aligned, + vm_end - vm_end_aligned, + (mach_vm_offset_t) 0, /* mask */ + VM_FLAGS_FIXED, + vmk_flags, + VM_KERN_MEMORY_NONE, + IPC_PORT_NULL, + 0, + FALSE, /* copy */ + (scp->initprot & VM_PROT_ALL), + (scp->maxprot & VM_PROT_ALL), + VM_INHERIT_DEFAULT); + } +#endif /* __arm64__ */ + + if (ret != KERN_SUCCESS) { + return LOAD_FAILURE; + } + return LOAD_SUCCESS; + } else { +#if CONFIG_EMBEDDED + /* not PAGEZERO: should not be mapped at address 0 */ + if (filetype != MH_DYLINKER && scp->vmaddr == 0) { + return LOAD_BADMACHO; + } +#endif /* CONFIG_EMBEDDED */ + } + +#if __arm64__ + if (fourk_align) { + /* 4K-align */ + file_start = vm_map_trunc_page(file_offset, + FOURK_PAGE_MASK); + file_end = vm_map_round_page(file_offset + file_size, + FOURK_PAGE_MASK); + vm_start = vm_map_trunc_page(vm_offset, + FOURK_PAGE_MASK); + vm_end = vm_map_round_page(vm_offset + vm_size, + FOURK_PAGE_MASK); + if (!strncmp(scp->segname, "__LINKEDIT", 11) && + page_aligned(file_start) && + vm_map_page_aligned(file_start, vm_map_page_mask(map)) && + page_aligned(vm_start) && + vm_map_page_aligned(vm_start, vm_map_page_mask(map))) { + /* XXX last segment: ignore mis-aligned tail */ + file_end = vm_map_round_page(file_end, + effective_page_mask); + vm_end = vm_map_round_page(vm_end, + effective_page_mask); + } + } else +#endif /* __arm64__ */ + { + file_start = vm_map_trunc_page(file_offset, + effective_page_mask); + file_end = vm_map_round_page(file_offset + file_size, + effective_page_mask); + vm_start = vm_map_trunc_page(vm_offset, + effective_page_mask); + vm_end = vm_map_round_page(vm_offset + vm_size, + effective_page_mask); + } + + if (vm_start < result->min_vm_addr) { + result->min_vm_addr = vm_start; + } + if (vm_end > result->max_vm_addr) { + result->max_vm_addr = vm_end; + } + + if (map == VM_MAP_NULL) { + return LOAD_SUCCESS; + } + + if (vm_size > 0) { + initprot = (scp->initprot) & VM_PROT_ALL; + maxprot = (scp->maxprot) & VM_PROT_ALL; + /* + * Map a copy of the file into the address space. + */ + if (verbose) { + MACHO_PRINTF(("++++++ load_segment: " + "mapping at vm [0x%llx:0x%llx] of " + "file [0x%llx:0x%llx]\n", + (uint64_t) vm_start, + (uint64_t) vm_end, + (uint64_t) file_start, + (uint64_t) file_end)); + } + ret = map_segment(map, + vm_start, + vm_end, + control, + file_start, + file_end, + initprot, + maxprot, + result); + if (ret) { + return LOAD_NOSPACE; + } + +#if FIXME + /* + * If the file didn't end on a page boundary, + * we need to zero the leftover. + */ + delta_size = map_size - scp->filesize; + if (delta_size > 0) { + mach_vm_offset_t tmp; + + ret = mach_vm_allocate_kernel(kernel_map, &tmp, delta_size, VM_FLAGS_ANYWHERE, VM_KERN_MEMORY_BSD); + if (ret != KERN_SUCCESS) { + return LOAD_RESOURCE; + } + + if (copyout(tmp, map_addr + scp->filesize, + delta_size)) { + (void) mach_vm_deallocate( + kernel_map, tmp, delta_size); + return LOAD_FAILURE; + } + + (void) mach_vm_deallocate(kernel_map, tmp, delta_size); + } +#endif /* FIXME */ + } + + /* + * If the virtual size of the segment is greater + * than the size from the file, we need to allocate + * zero fill memory for the rest. + */ + if ((vm_end - vm_start) > (file_end - file_start)) { + delta_size = (vm_end - vm_start) - (file_end - file_start); + } else { + delta_size = 0; + } + if (delta_size > 0) { + mach_vm_offset_t tmp; + + tmp = vm_start + (file_end - file_start); + if (verbose) { + MACHO_PRINTF(("++++++ load_segment: " + "delta mapping vm [0x%llx:0x%llx]\n", + (uint64_t) tmp, + (uint64_t) (tmp + delta_size))); + } + kr = map_segment(map, + tmp, + tmp + delta_size, + MEMORY_OBJECT_CONTROL_NULL, + 0, + delta_size, + scp->initprot, + scp->maxprot, + result); + if (kr != KERN_SUCCESS) { + return LOAD_NOSPACE; + } + } + + if ((scp->fileoff == 0) && (scp->filesize != 0)) { + result->mach_header = vm_offset; + } + + if (scp->flags & SG_PROTECTED_VERSION_1) { + ret = unprotect_dsmos_segment(file_start, + file_end - file_start, + vp, + pager_offset, + map, + vm_start, + vm_end - vm_start); + if (ret != LOAD_SUCCESS) { + return ret; + } + } else { + ret = LOAD_SUCCESS; + } + + if (LOAD_SUCCESS == ret && + filetype == MH_DYLINKER && + result->all_image_info_addr == MACH_VM_MIN_ADDRESS) { + note_all_image_info_section(scp, + LC_SEGMENT_64 == lcp->cmd, + single_section_size, + ((const char *)lcp + + segment_command_size), + slide, + result); + } + + if (result->entry_point != MACH_VM_MIN_ADDRESS) { + if ((result->entry_point >= vm_offset) && (result->entry_point < (vm_offset + vm_size))) { + if ((scp->initprot & (VM_PROT_READ | VM_PROT_EXECUTE)) == (VM_PROT_READ | VM_PROT_EXECUTE)) { + result->validentry = 1; + } else { + /* right range but wrong protections, unset if previously validated */ + result->validentry = 0; + } + } + } + + return ret; +} + +static +load_return_t +load_uuid( + struct uuid_command *uulp, + char *command_end, + load_result_t *result + ) +{ + /* + * We need to check the following for this command: + * - The command size should be atleast the size of struct uuid_command + * - The UUID part of the command should be completely within the mach-o header + */ + + if ((uulp->cmdsize < sizeof(struct uuid_command)) || + (((char *)uulp + sizeof(struct uuid_command)) > command_end)) { + return LOAD_BADMACHO; + } + + memcpy(&result->uuid[0], &uulp->uuid[0], sizeof(result->uuid)); + return LOAD_SUCCESS; +} + +static +load_return_t +load_version( + struct version_min_command *vmc, + boolean_t *found_version_cmd, + load_result_t *result + ) +{ + uint32_t platform = 0; + uint32_t sdk; + + if (vmc->cmdsize < sizeof(*vmc)) { + return LOAD_BADMACHO; + } + if (*found_version_cmd == TRUE) { + return LOAD_BADMACHO; + } + *found_version_cmd = TRUE; + sdk = vmc->sdk; + switch (vmc->cmd) { + case LC_VERSION_MIN_MACOSX: + platform = PLATFORM_MACOS; + break; +#if __x86_64__ /* __x86_64__ */ + case LC_VERSION_MIN_IPHONEOS: + platform = PLATFORM_IOSSIMULATOR; + break; + case LC_VERSION_MIN_WATCHOS: + platform = PLATFORM_WATCHOSSIMULATOR; + break; + case LC_VERSION_MIN_TVOS: + platform = PLATFORM_TVOSSIMULATOR; + break; +#else + case LC_VERSION_MIN_IPHONEOS: { +#if __arm64__ + extern int legacy_footprint_entitlement_mode; + if (vmc->sdk < (12 << 16)) { + /* app built with a pre-iOS12 SDK: apply legacy footprint mitigation */ + result->legacy_footprint = TRUE; + } +#endif /* __arm64__ */ + platform = PLATFORM_IOS; + break; + } + case LC_VERSION_MIN_WATCHOS: + platform = PLATFORM_WATCHOS; + break; + case LC_VERSION_MIN_TVOS: + platform = PLATFORM_TVOS; + break; +#endif /* __x86_64__ */ + /* All LC_VERSION_MIN_* load commands are legacy and we will not be adding any more */ + default: + sdk = (uint32_t)-1; + __builtin_unreachable(); + } + result->ip_platform = platform; + result->lr_sdk = sdk; + return LOAD_SUCCESS; +} + +static +load_return_t +load_main( + struct entry_point_command *epc, + thread_t thread, + int64_t slide, + load_result_t *result + ) +{ + mach_vm_offset_t addr; + kern_return_t ret; + + if (epc->cmdsize < sizeof(*epc)) { + return LOAD_BADMACHO; + } + if (result->thread_count != 0) { + return LOAD_FAILURE; + } + + if (thread == THREAD_NULL) { + return LOAD_SUCCESS; + } /* - * Round sizes to page size. + * LC_MAIN specifies stack size but not location. + * Add guard page to allocation size (MAXSSIZ includes guard page). */ - seg_size = round_page_64(scp->vmsize); - map_size = round_page_64(scp->filesize); - map_addr = trunc_page_64(scp->vmaddr); /* JVXXX note that in XNU TOT this is round instead of trunc for 64 bits */ - if (seg_size == 0) - return (KERN_SUCCESS); - if (map_addr == 0 && - map_size == 0 && - seg_size != 0 && - (scp->initprot & VM_PROT_ALL) == VM_PROT_NONE && - (scp->maxprot & VM_PROT_ALL) == VM_PROT_NONE) { - /* - * For PIE, extend page zero rather than moving it. Extending - * page zero keeps early allocations from falling predictably - * between the end of page zero and the beginning of the first - * slid segment. - */ - seg_size += slide; - slide = 0; - - /* XXX (4596982) this interferes with Rosetta, so limit to 64-bit tasks */ - if (scp->cmd == LC_SEGMENT_64) { + if (epc->stacksize) { + if (os_add_overflow(epc->stacksize, 4 * PAGE_SIZE, &result->user_stack_size)) { /* - * This is a "page zero" segment: it starts at address 0, - * is not mapped from the binary file and is not accessible. - * User-space should never be able to access that memory, so - * make it completely off limits by raising the VM map's - * minimum offset. + * We are going to immediately throw away this result, but we want + * to make sure we aren't loading a dangerously close to + * overflowing value, since this will have a guard page added to it + * and be rounded to page boundaries */ - ret = vm_map_raise_min_offset(map, seg_size); - if (ret != KERN_SUCCESS) { - return (LOAD_FAILURE); - } - return (LOAD_SUCCESS); + return LOAD_BADMACHO; + } + result->user_stack_size = epc->stacksize; + if (os_add_overflow(epc->stacksize, PAGE_SIZE, &result->user_stack_alloc_size)) { + return LOAD_BADMACHO; } + result->custom_stack = TRUE; + } else { + result->user_stack_alloc_size = MAXSSIZ; } - /* If a non-zero slide was specified by the caller, apply now */ - map_addr += slide; + /* use default location for stack */ + ret = thread_userstackdefault(&addr, result->is_64bit_addr); + if (ret != KERN_SUCCESS) { + return LOAD_FAILURE; + } - if (map_addr < result->min_vm_addr) - result->min_vm_addr = map_addr; - if (map_addr+seg_size > result->max_vm_addr) - result->max_vm_addr = map_addr+seg_size; + /* The stack slides down from the default location */ + result->user_stack = addr; + result->user_stack -= slide; - if (map == VM_MAP_NULL) - return (LOAD_SUCCESS); + if (result->using_lcmain || result->entry_point != MACH_VM_MIN_ADDRESS) { + /* Already processed LC_MAIN or LC_UNIXTHREAD */ + return LOAD_FAILURE; + } - map_offset = pager_offset + scp->fileoff; /* limited to 32 bits */ + /* kernel does *not* use entryoff from LC_MAIN. Dyld uses it. */ + result->needs_dynlinker = TRUE; + result->using_lcmain = TRUE; - if (map_size > 0) { - initprot = (scp->initprot) & VM_PROT_ALL; - maxprot = (scp->maxprot) & VM_PROT_ALL; - /* - * Map a copy of the file into the address space. - */ - ret = vm_map_enter_mem_object_control(map, - &map_addr, map_size, (mach_vm_offset_t)0, - VM_FLAGS_FIXED, control, map_offset, TRUE, - initprot, maxprot, - VM_INHERIT_DEFAULT); - if (ret != KERN_SUCCESS) - return (LOAD_NOSPACE); - - /* - * If the file didn't end on a page boundary, - * we need to zero the leftover. - */ - delta_size = map_size - scp->filesize; -#if FIXME - if (delta_size > 0) { - mach_vm_offset_t tmp; - - ret = mach_vm_allocate(kernel_map, &tmp, delta_size, VM_FLAGS_ANYWHERE); - if (ret != KERN_SUCCESS) - return(LOAD_RESOURCE); - - if (copyout(tmp, map_addr + scp->filesize, - delta_size)) { - (void) mach_vm_deallocate( - kernel_map, tmp, delta_size); - return (LOAD_FAILURE); - } - - (void) mach_vm_deallocate(kernel_map, tmp, delta_size); - } -#endif /* FIXME */ + ret = thread_state_initialize( thread ); + if (ret != KERN_SUCCESS) { + return LOAD_FAILURE; } - /* - * If the virtual size of the segment is greater - * than the size from the file, we need to allocate - * zero fill memory for the rest. - */ - delta_size = seg_size - map_size; - if (delta_size > 0) { - mach_vm_offset_t tmp = map_addr + map_size; + result->unixproc = TRUE; + result->thread_count++; + + return LOAD_SUCCESS; +} - ret = mach_vm_map(map, &tmp, delta_size, 0, VM_FLAGS_FIXED, - NULL, 0, FALSE, - scp->initprot, scp->maxprot, - VM_INHERIT_DEFAULT); - if (ret != KERN_SUCCESS) - return(LOAD_NOSPACE); +static +load_return_t +setup_driver_main( + thread_t thread, + int64_t slide, + load_result_t *result + ) +{ + mach_vm_offset_t addr; + kern_return_t ret; + + /* Driver binaries have no LC_MAIN, use defaults */ + + if (thread == THREAD_NULL) { + return LOAD_SUCCESS; } - if ( (scp->fileoff == 0) && (scp->filesize != 0) ) - result->mach_header = map_addr; + result->user_stack_alloc_size = MAXSSIZ; - if (scp->flags & SG_PROTECTED_VERSION_1) { - ret = unprotect_segment(scp->fileoff, - scp->filesize, - vp, - pager_offset, - map, - map_addr, - map_size); - } else { - ret = LOAD_SUCCESS; + /* use default location for stack */ + ret = thread_userstackdefault(&addr, result->is_64bit_addr); + if (ret != KERN_SUCCESS) { + return LOAD_FAILURE; } - if (LOAD_SUCCESS == ret && filetype == MH_DYLINKER && - result->all_image_info_addr == MACH_VM_MIN_ADDRESS) - note_all_image_info_section(scp, - LC_SEGMENT_64 == lcp->cmd, single_section_size, - (const char *)lcp + segment_command_size, slide, result); - if ((result->entry_point >= map_addr) && (result->entry_point < (map_addr + map_size))) - result->validentry = 1; + /* The stack slides down from the default location */ + result->user_stack = addr; + result->user_stack -= slide; - return ret; + if (result->using_lcmain || result->entry_point != MACH_VM_MIN_ADDRESS) { + /* Already processed LC_MAIN or LC_UNIXTHREAD */ + return LOAD_FAILURE; + } + + result->needs_dynlinker = TRUE; + + ret = thread_state_initialize( thread ); + if (ret != KERN_SUCCESS) { + return LOAD_FAILURE; + } + + result->unixproc = TRUE; + result->thread_count++; + + return LOAD_SUCCESS; } static load_return_t load_unixthread( - struct thread_command *tcp, - thread_t thread, - int64_t slide, - load_result_t *result -) + struct thread_command *tcp, + thread_t thread, + int64_t slide, + load_result_t *result + ) { - load_return_t ret; - int customstack =0; - - if (tcp->cmdsize < sizeof(*tcp)) - return (LOAD_BADMACHO); + load_return_t ret; + int customstack = 0; + mach_vm_offset_t addr; + if (tcp->cmdsize < sizeof(*tcp)) { + return LOAD_BADMACHO; + } if (result->thread_count != 0) { - printf("load_unixthread: already have a thread!"); - return (LOAD_FAILURE); + return LOAD_FAILURE; + } + + if (thread == THREAD_NULL) { + return LOAD_SUCCESS; } - if (thread == THREAD_NULL) - return (LOAD_SUCCESS); - ret = load_threadstack(thread, - (uint32_t *)(((vm_offset_t)tcp) + - sizeof(struct thread_command)), - tcp->cmdsize - sizeof(struct thread_command), - &result->user_stack, - &customstack); - if (ret != LOAD_SUCCESS) - return(ret); + (uint32_t *)(((vm_offset_t)tcp) + + sizeof(struct thread_command)), + tcp->cmdsize - sizeof(struct thread_command), + &addr, &customstack, result); + if (ret != LOAD_SUCCESS) { + return ret; + } - if (customstack) - result->customstack = 1; - else - result->customstack = 0; + /* LC_UNIXTHREAD optionally specifies stack size and location */ - result->user_stack += slide; + if (customstack) { + result->custom_stack = TRUE; + } else { + result->user_stack_alloc_size = MAXSSIZ; + } + + /* The stack slides down from the default location */ + result->user_stack = addr; + result->user_stack -= slide; ret = load_threadentry(thread, - (uint32_t *)(((vm_offset_t)tcp) + - sizeof(struct thread_command)), - tcp->cmdsize - sizeof(struct thread_command), - &result->entry_point); - if (ret != LOAD_SUCCESS) - return(ret); + (uint32_t *)(((vm_offset_t)tcp) + + sizeof(struct thread_command)), + tcp->cmdsize - sizeof(struct thread_command), + &addr); + if (ret != LOAD_SUCCESS) { + return ret; + } + if (result->using_lcmain || result->entry_point != MACH_VM_MIN_ADDRESS) { + /* Already processed LC_MAIN or LC_UNIXTHREAD */ + return LOAD_FAILURE; + } + + result->entry_point = addr; result->entry_point += slide; ret = load_threadstate(thread, - (uint32_t *)(((vm_offset_t)tcp) + - sizeof(struct thread_command)), - tcp->cmdsize - sizeof(struct thread_command)); - if (ret != LOAD_SUCCESS) - return (ret); + (uint32_t *)(((vm_offset_t)tcp) + sizeof(struct thread_command)), + tcp->cmdsize - sizeof(struct thread_command), + result); + if (ret != LOAD_SUCCESS) { + return ret; + } result->unixproc = TRUE; result->thread_count++; - return(LOAD_SUCCESS); + return LOAD_SUCCESS; } static load_return_t load_threadstate( - thread_t thread, - uint32_t *ts, - uint32_t total_size -) + thread_t thread, + uint32_t *ts, + uint32_t total_size, + load_result_t *result + ) { - kern_return_t ret; - uint32_t size; - int flavor; - uint32_t thread_size; - - ret = thread_state_initialize( thread ); - if (ret != KERN_SUCCESS) { - return(LOAD_FAILURE); - } - + uint32_t size; + int flavor; + uint32_t thread_size; + uint32_t *local_ts = NULL; + uint32_t local_ts_size = 0; + int ret; + + (void)thread; + + if (total_size > 0) { + local_ts_size = total_size; + local_ts = kalloc(local_ts_size); + if (local_ts == NULL) { + return LOAD_FAILURE; + } + memcpy(local_ts, ts, local_ts_size); + ts = local_ts; + } + /* - * Set the new thread state; iterate through the state flavors in - * the mach-o file. + * Validate the new thread state; iterate through the state flavors in + * the Mach-O file. + * XXX: we should validate the machine state here, to avoid failing at + * activation time where we can't bail out cleanly. */ while (total_size > 0) { flavor = *ts++; size = *ts++; - if (UINT32_MAX-2 < size || - UINT32_MAX/sizeof(uint32_t) < size+2) - return (LOAD_BADMACHO); - thread_size = (size+2)*sizeof(uint32_t); - if (thread_size > total_size) - return(LOAD_BADMACHO); - total_size -= thread_size; - /* - * Third argument is a kernel space pointer; it gets cast - * to the appropriate type in machine_thread_set_state() - * based on the value of flavor. - */ - ret = thread_setstatus(thread, flavor, (thread_state_t)ts, size); - if (ret != KERN_SUCCESS) { - return(LOAD_FAILURE); + + if (os_add_and_mul_overflow(size, 2, sizeof(uint32_t), &thread_size) || + os_sub_overflow(total_size, thread_size, &total_size)) { + ret = LOAD_BADMACHO; + goto bad; } - ts += size; /* ts is a (uint32_t *) */ + + ts += size; /* ts is a (uint32_t *) */ + } + + result->threadstate = local_ts; + result->threadstate_sz = local_ts_size; + return LOAD_SUCCESS; + +bad: + if (local_ts) { + kfree(local_ts, local_ts_size); } - return(LOAD_SUCCESS); + return ret; } static load_return_t load_threadstack( - thread_t thread, - uint32_t *ts, - uint32_t total_size, - mach_vm_offset_t *user_stack, - int *customstack -) + thread_t thread, + uint32_t *ts, + uint32_t total_size, + mach_vm_offset_t *user_stack, + int *customstack, + load_result_t *result + ) { - kern_return_t ret; - uint32_t size; - int flavor; - uint32_t stack_size; + kern_return_t ret; + uint32_t size; + int flavor; + uint32_t stack_size; while (total_size > 0) { flavor = *ts++; size = *ts++; - if (UINT32_MAX-2 < size || - UINT32_MAX/sizeof(uint32_t) < size+2) - return (LOAD_BADMACHO); - stack_size = (size+2)*sizeof(uint32_t); - if (stack_size > total_size) - return(LOAD_BADMACHO); + if (UINT32_MAX - 2 < size || + UINT32_MAX / sizeof(uint32_t) < size + 2) { + return LOAD_BADMACHO; + } + stack_size = (size + 2) * sizeof(uint32_t); + if (stack_size > total_size) { + return LOAD_BADMACHO; + } total_size -= stack_size; /* @@ -1139,28 +2597,28 @@ load_threadstack( * to the appropriate type in thread_userstack() based on * the value of flavor. */ - ret = thread_userstack(thread, flavor, (thread_state_t)ts, size, user_stack, customstack); + ret = thread_userstack(thread, flavor, (thread_state_t)ts, size, user_stack, customstack, result->is_64bit_data); if (ret != KERN_SUCCESS) { - return(LOAD_FAILURE); + return LOAD_FAILURE; } - ts += size; /* ts is a (uint32_t *) */ + ts += size; /* ts is a (uint32_t *) */ } - return(LOAD_SUCCESS); + return LOAD_SUCCESS; } static load_return_t load_threadentry( - thread_t thread, - uint32_t *ts, - uint32_t total_size, - mach_vm_offset_t *entry_point -) + thread_t thread, + uint32_t *ts, + uint32_t total_size, + mach_vm_offset_t *entry_point + ) { - kern_return_t ret; - uint32_t size; - int flavor; - uint32_t entry_size; + kern_return_t ret; + uint32_t size; + int flavor; + uint32_t entry_size; /* * Set the thread state. @@ -1169,12 +2627,14 @@ load_threadentry( while (total_size > 0) { flavor = *ts++; size = *ts++; - if (UINT32_MAX-2 < size || - UINT32_MAX/sizeof(uint32_t) < size+2) - return (LOAD_BADMACHO); - entry_size = (size+2)*sizeof(uint32_t); - if (entry_size > total_size) - return(LOAD_BADMACHO); + if (UINT32_MAX - 2 < size || + UINT32_MAX / sizeof(uint32_t) < size + 2) { + return LOAD_BADMACHO; + } + entry_size = (size + 2) * sizeof(uint32_t); + if (entry_size > total_size) { + return LOAD_BADMACHO; + } total_size -= entry_size; /* * Third argument is a kernel space pointer; it gets cast @@ -1183,198 +2643,224 @@ load_threadentry( */ ret = thread_entrypoint(thread, flavor, (thread_state_t)ts, size, entry_point); if (ret != KERN_SUCCESS) { - return(LOAD_FAILURE); + return LOAD_FAILURE; } - ts += size; /* ts is a (uint32_t *) */ + ts += size; /* ts is a (uint32_t *) */ } - return(LOAD_SUCCESS); + return LOAD_SUCCESS; } struct macho_data { - struct nameidata __nid; + struct nameidata __nid; union macho_vnode_header { - struct mach_header mach_header; - struct fat_header fat_header; - char __pad[512]; + struct mach_header mach_header; + struct fat_header fat_header; + char __pad[512]; } __header; }; +#define DEFAULT_DYLD_PATH "/usr/lib/dyld" + +#if (DEVELOPMENT || DEBUG) +extern char dyld_alt_path[]; +extern int use_alt_dyld; +#endif + static load_return_t load_dylinker( - struct dylinker_command *lcp, - integer_t archbits, - vm_map_t map, - thread_t thread, - int depth, - int64_t slide, - load_result_t *result -) + struct dylinker_command *lcp, + integer_t archbits, + vm_map_t map, + thread_t thread, + int depth, + int64_t slide, + load_result_t *result, + struct image_params *imgp + ) { - char *name; - char *p; - struct vnode *vp = NULLVP; /* set by get_macho_vnode() */ - struct mach_header *header; - off_t file_offset = 0; /* set by get_macho_vnode() */ - off_t macho_size = 0; /* set by get_macho_vnode() */ - load_result_t *myresult; - kern_return_t ret; - struct macho_data *macho_data; + const char *name; + struct vnode *vp = NULLVP; /* set by get_macho_vnode() */ + struct mach_header *header; + off_t file_offset = 0; /* set by get_macho_vnode() */ + off_t macho_size = 0; /* set by get_macho_vnode() */ + load_result_t *myresult; + kern_return_t ret; + struct macho_data *macho_data; struct { - struct mach_header __header; - load_result_t __myresult; - struct macho_data __macho_data; + struct mach_header __header; + load_result_t __myresult; + struct macho_data __macho_data; } *dyld_data; - if (lcp->cmdsize < sizeof(*lcp)) - return (LOAD_BADMACHO); + if (lcp->cmdsize < sizeof(*lcp) || lcp->name.offset >= lcp->cmdsize) { + return LOAD_BADMACHO; + } + + name = (const char *)lcp + lcp->name.offset; + + /* Check for a proper null terminated string. */ + size_t maxsz = lcp->cmdsize - lcp->name.offset; + size_t namelen = strnlen(name, maxsz); + if (namelen >= maxsz) { + return LOAD_BADMACHO; + } + +#if (DEVELOPMENT || DEBUG) - name = (char *)lcp + lcp->name.offset; /* - * Check for a proper null terminated string. + * rdar://23680808 + * If an alternate dyld has been specified via boot args, check + * to see if PROC_UUID_ALT_DYLD_POLICY has been set on this + * executable and redirect the kernel to load that linker. */ - p = name; - do { - if (p >= (char *)lcp + lcp->cmdsize) - return(LOAD_BADMACHO); - } while (*p++); + + if (use_alt_dyld) { + int policy_error; + uint32_t policy_flags = 0; + int32_t policy_gencount = 0; + + policy_error = proc_uuid_policy_lookup(result->uuid, &policy_flags, &policy_gencount); + if (policy_error == 0) { + if (policy_flags & PROC_UUID_ALT_DYLD_POLICY) { + name = dyld_alt_path; + } + } + } +#endif + +#if !(DEVELOPMENT || DEBUG) + if (0 != strcmp(name, DEFAULT_DYLD_PATH)) { + return LOAD_BADMACHO; + } +#endif /* Allocate wad-of-data from heap to reduce excessively deep stacks */ - MALLOC(dyld_data, void *, sizeof (*dyld_data), M_TEMP, M_WAITOK); + MALLOC(dyld_data, void *, sizeof(*dyld_data), M_TEMP, M_WAITOK); header = &dyld_data->__header; myresult = &dyld_data->__myresult; macho_data = &dyld_data->__macho_data; ret = get_macho_vnode(name, archbits, header, &file_offset, &macho_size, macho_data, &vp); - if (ret) + if (ret) { goto novp_out; + } *myresult = load_result_null; - - /* - * First try to map dyld in directly. This should work most of - * the time since there shouldn't normally be something already - * mapped to its address. - */ + myresult->is_64bit_addr = result->is_64bit_addr; + myresult->is_64bit_data = result->is_64bit_data; ret = parse_machfile(vp, map, thread, header, file_offset, - macho_size, depth, slide, myresult); - - /* - * If it turned out something was in the way, then we'll take - * take this longer path to preflight dyld's vm ranges, then - * map it at a free location in the address space. - */ - - if (ret == LOAD_NOSPACE) { - mach_vm_offset_t dyl_start, map_addr; - mach_vm_size_t dyl_length; - int64_t slide_amount; - - *myresult = load_result_null; - - /* - * Preflight parsing the Mach-O file with a NULL - * map, which will return the ranges needed for a - * subsequent map attempt (with a slide) in "myresult" - */ - ret = parse_machfile(vp, VM_MAP_NULL, THREAD_NULL, header, - file_offset, macho_size, depth, 0 /* slide */, myresult); - - if (ret != LOAD_SUCCESS) { - goto out; - } - - dyl_start = myresult->min_vm_addr; - dyl_length = myresult->max_vm_addr - myresult->min_vm_addr; + macho_size, depth, slide, 0, myresult, result, imgp); - dyl_length += slide; - - /* To find an appropriate load address, do a quick allocation */ - map_addr = dyl_start; - ret = mach_vm_allocate(map, &map_addr, dyl_length, VM_FLAGS_ANYWHERE); - if (ret != KERN_SUCCESS) { - ret = LOAD_NOSPACE; - goto out; - } - - ret = mach_vm_deallocate(map, map_addr, dyl_length); - if (ret != KERN_SUCCESS) { - ret = LOAD_NOSPACE; - goto out; - } - - if (map_addr < dyl_start) - slide_amount = -(int64_t)(dyl_start - map_addr); - else - slide_amount = (int64_t)(map_addr - dyl_start); - - slide_amount += slide; - - *myresult = load_result_null; - - ret = parse_machfile(vp, map, thread, header, - file_offset, macho_size, depth, slide_amount, myresult); - - if (ret) { - goto out; + if (ret == LOAD_SUCCESS) { + if (result->threadstate) { + /* don't use the app's threadstate if we have a dyld */ + kfree(result->threadstate, result->threadstate_sz); } - } + result->threadstate = myresult->threadstate; + result->threadstate_sz = myresult->threadstate_sz; - if (ret == LOAD_SUCCESS) { result->dynlinker = TRUE; result->entry_point = myresult->entry_point; + result->validentry = myresult->validentry; result->all_image_info_addr = myresult->all_image_info_addr; result->all_image_info_size = myresult->all_image_info_size; + if (myresult->platform_binary) { + result->csflags |= CS_DYLD_PLATFORM; + } } -out: + + struct vnode_attr va; + VATTR_INIT(&va); + VATTR_WANTED(&va, va_fsid64); + VATTR_WANTED(&va, va_fsid); + VATTR_WANTED(&va, va_fileid); + int error = vnode_getattr(vp, &va, imgp->ip_vfs_context); + if (error == 0) { + imgp->ip_dyld_fsid = vnode_get_va_fsid(&va); + imgp->ip_dyld_fsobjid = va.va_fileid; + } + vnode_put(vp); novp_out: FREE(dyld_data, M_TEMP); - return (ret); - + return ret; } static load_return_t load_code_signature( - struct linkedit_data_command *lcp, - struct vnode *vp, - off_t macho_offset, - off_t macho_size, - cpu_type_t cputype, - load_result_t *result) + struct linkedit_data_command *lcp, + struct vnode *vp, + off_t macho_offset, + off_t macho_size, + cpu_type_t cputype, + load_result_t *result, + struct image_params *imgp) { - int ret; - kern_return_t kr; - vm_offset_t addr; - int resid; - struct cs_blob *blob; - int error; - vm_size_t blob_size; + int ret; + kern_return_t kr; + vm_offset_t addr; + int resid; + struct cs_blob *blob; + int error; + vm_size_t blob_size; + uint32_t sum; addr = 0; blob = NULL; - if (lcp->cmdsize != sizeof (struct linkedit_data_command) || - lcp->dataoff + lcp->datasize > macho_size) { + if (lcp->cmdsize != sizeof(struct linkedit_data_command)) { + ret = LOAD_BADMACHO; + goto out; + } + + sum = 0; + if (os_add_overflow(lcp->dataoff, lcp->datasize, &sum) || sum > macho_size) { ret = LOAD_BADMACHO; goto out; } - blob = ubc_cs_blob_get(vp, cputype, -1); + blob = ubc_cs_blob_get(vp, cputype, macho_offset); + if (blob != NULL) { /* we already have a blob for this vnode and cputype */ - if (blob->csb_cpu_type == cputype && - blob->csb_base_offset == macho_offset && - blob->csb_mem_size == lcp->datasize) { - /* it matches the blob we want here: we're done */ - ret = LOAD_SUCCESS; - } else { + if (blob->csb_cpu_type != cputype || + blob->csb_base_offset != macho_offset) { /* the blob has changed for this vnode: fail ! */ ret = LOAD_BADMACHO; + goto out; } - goto out; + + /* It matches the blob we want here, let's verify the version */ + if (ubc_cs_generation_check(vp) == 0) { + /* No need to revalidate, we're good! */ + ret = LOAD_SUCCESS; + goto out; + } + + /* That blob may be stale, let's revalidate. */ + error = ubc_cs_blob_revalidate(vp, blob, imgp, 0); + if (error == 0) { + /* Revalidation succeeded, we're good! */ + ret = LOAD_SUCCESS; + goto out; + } + + if (error != EAGAIN) { + printf("load_code_signature: revalidation failed: %d\n", error); + ret = LOAD_FAILURE; + goto out; + } + + assert(error == EAGAIN); + + /* + * Revalidation was not possible for this blob. We just continue as if there was no blob, + * rereading the signature, and ubc_cs_blob_add will do the right thing. + */ + blob = NULL; } blob_size = lcp->datasize; @@ -1383,28 +2869,34 @@ load_code_signature( ret = LOAD_NOSPACE; goto out; } - + resid = 0; error = vn_rdwr(UIO_READ, - vp, - (caddr_t) addr, - lcp->datasize, - macho_offset + lcp->dataoff, - UIO_SYSSPACE, - 0, - kauth_cred_get(), - &resid, - current_proc()); + vp, + (caddr_t) addr, + lcp->datasize, + macho_offset + lcp->dataoff, + UIO_SYSSPACE, + 0, + kauth_cred_get(), + &resid, + current_proc()); if (error || resid != 0) { ret = LOAD_IOERROR; goto out; } if (ubc_cs_blob_add(vp, - cputype, - macho_offset, - addr, - lcp->datasize)) { + cputype, + macho_offset, + &addr, + lcp->datasize, + imgp, + 0, + &blob)) { + if (addr) { + ubc_cs_blob_deallocate(addr, blob_size); + } ret = LOAD_FAILURE; goto out; } else { @@ -1415,13 +2907,17 @@ load_code_signature( #if CHECK_CS_VALIDATION_BITMAP ubc_cs_validation_bitmap_allocate( vp ); #endif - - blob = ubc_cs_blob_get(vp, cputype, -1); ret = LOAD_SUCCESS; out: - if (result && ret == LOAD_SUCCESS) { + if (ret == LOAD_SUCCESS) { + if (blob == NULL) { + panic("success, but no blob!"); + } + result->csflags |= blob->csb_flags; + result->platform_binary = blob->csb_platform_binary; + result->cs_end_offset = blob->csb_end_offset; } if (addr != 0) { ubc_cs_blob_deallocate(addr, blob_size); @@ -1436,63 +2932,94 @@ out: static load_return_t set_code_unprotect( - struct encryption_info_command *eip, - caddr_t addr, - vm_map_t map, - struct vnode *vp) + struct encryption_info_command *eip, + caddr_t addr, + vm_map_t map, + int64_t slide, + struct vnode *vp, + off_t macho_offset, + cpu_type_t cputype, + cpu_subtype_t cpusubtype) { - int result, len; + int error, len; pager_crypt_info_t crypt_info; const char * cryptname = 0; char *vpath; - + size_t offset; struct segment_command_64 *seg64; struct segment_command *seg32; vm_map_offset_t map_offset, map_size; + vm_object_offset_t crypto_backing_offset; kern_return_t kr; - if (eip->cmdsize < sizeof(*eip)) return LOAD_BADMACHO; - - switch(eip->cryptid) { - case 0: - /* not encrypted, just an empty load command */ - return LOAD_SUCCESS; - case 1: - cryptname="com.apple.unfree"; - break; - case 0x10: - /* some random cryptid that you could manually put into - * your binary if you want NULL */ - cryptname="com.apple.null"; - break; - default: - return LOAD_BADMACHO; + if (eip->cmdsize < sizeof(*eip)) { + return LOAD_BADMACHO; + } + + switch (eip->cryptid) { + case 0: + /* not encrypted, just an empty load command */ + return LOAD_SUCCESS; + case 1: + cryptname = "com.apple.unfree"; + break; + case 0x10: + /* some random cryptid that you could manually put into + * your binary if you want NULL */ + cryptname = "com.apple.null"; + break; + default: + return LOAD_BADMACHO; + } + + if (map == VM_MAP_NULL) { + return LOAD_SUCCESS; + } + if (NULL == text_crypter_create) { + return LOAD_FAILURE; } - - if (map == VM_MAP_NULL) return (LOAD_SUCCESS); - if (NULL == text_crypter_create) return LOAD_FAILURE; MALLOC_ZONE(vpath, char *, MAXPATHLEN, M_NAMEI, M_WAITOK); - if(vpath == NULL) return LOAD_FAILURE; - + if (vpath == NULL) { + return LOAD_FAILURE; + } + len = MAXPATHLEN; - result = vn_getpath(vp, vpath, &len); - if(result) { + error = vn_getpath(vp, vpath, &len); + if (error) { FREE_ZONE(vpath, MAXPATHLEN, M_NAMEI); return LOAD_FAILURE; } - + /* set up decrypter first */ - kr=text_crypter_create(&crypt_info, cryptname, (void*)vpath); + crypt_file_data_t crypt_data = { + .filename = vpath, + .cputype = cputype, + .cpusubtype = cpusubtype + }; + kr = text_crypter_create(&crypt_info, cryptname, (void*)&crypt_data); +#if VM_MAP_DEBUG_APPLE_PROTECT + if (vm_map_debug_apple_protect) { + struct proc *p; + p = current_proc(); + printf("APPLE_PROTECT: %d[%s] map %p %s(%s) -> 0x%x\n", + p->p_pid, p->p_comm, map, __FUNCTION__, vpath, kr); + } +#endif /* VM_MAP_DEBUG_APPLE_PROTECT */ FREE_ZONE(vpath, MAXPATHLEN, M_NAMEI); - - if(kr) { + + if (kr) { printf("set_code_unprotect: unable to create decrypter %s, kr=%d\n", - cryptname, kr); - return LOAD_RESOURCE; + cryptname, kr); + if (kr == kIOReturnNotPrivileged) { + /* text encryption returned decryption failure */ + return LOAD_DECRYPTFAIL; + } else { + return LOAD_RESOURCE; + } } - + /* this is terrible, but we have to rescan the load commands to find the * virtual address of this encrypted stuff. This code is gonna look like * the dyld source one day... */ @@ -1500,7 +3027,7 @@ set_code_unprotect( size_t mach_header_sz = sizeof(struct mach_header); if (header->magic == MH_MAGIC_64 || header->magic == MH_CIGAM_64) { - mach_header_sz = sizeof(struct mach_header_64); + mach_header_sz = sizeof(struct mach_header_64); } offset = mach_header_sz; uint32_t ncmds = header->ncmds; @@ -1510,41 +3037,49 @@ set_code_unprotect( */ struct load_command *lcp = (struct load_command *)(addr + offset); offset += lcp->cmdsize; - - switch(lcp->cmd) { - case LC_SEGMENT_64: - seg64 = (struct segment_command_64 *)lcp; - if ((seg64->fileoff <= eip->cryptoff) && - (seg64->fileoff+seg64->filesize >= - eip->cryptoff+eip->cryptsize)) { - map_offset = seg64->vmaddr + eip->cryptoff - seg64->fileoff; - map_size = eip->cryptsize; - goto remap_now; - } - case LC_SEGMENT: - seg32 = (struct segment_command *)lcp; - if ((seg32->fileoff <= eip->cryptoff) && - (seg32->fileoff+seg32->filesize >= - eip->cryptoff+eip->cryptsize)) { - map_offset = seg32->vmaddr + eip->cryptoff - seg32->fileoff; - map_size = eip->cryptsize; - goto remap_now; - } + + switch (lcp->cmd) { + case LC_SEGMENT_64: + seg64 = (struct segment_command_64 *)lcp; + if ((seg64->fileoff <= eip->cryptoff) && + (seg64->fileoff + seg64->filesize >= + eip->cryptoff + eip->cryptsize)) { + map_offset = seg64->vmaddr + eip->cryptoff - seg64->fileoff + slide; + map_size = eip->cryptsize; + crypto_backing_offset = macho_offset + eip->cryptoff; + goto remap_now; + } + case LC_SEGMENT: + seg32 = (struct segment_command *)lcp; + if ((seg32->fileoff <= eip->cryptoff) && + (seg32->fileoff + seg32->filesize >= + eip->cryptoff + eip->cryptsize)) { + map_offset = seg32->vmaddr + eip->cryptoff - seg32->fileoff + slide; + map_size = eip->cryptsize; + crypto_backing_offset = macho_offset + eip->cryptoff; + goto remap_now; + } } } - + /* if we get here, did not find anything */ return LOAD_BADMACHO; - + remap_now: /* now remap using the decrypter */ - kr = vm_map_apple_protected(map, map_offset, map_offset+map_size, &crypt_info); - if(kr) { + MACHO_PRINTF(("+++ set_code_unprotect: vm[0x%llx:0x%llx]\n", + (uint64_t) map_offset, + (uint64_t) (map_offset + map_size))); + kr = vm_map_apple_protected(map, + map_offset, + map_offset + map_size, + crypto_backing_offset, + &crypt_info); + if (kr) { printf("set_code_unprotect(): mapping failed with %x\n", kr); - crypt_info.crypt_end(crypt_info.crypt_ops); return LOAD_PROTECT; } - + return LOAD_SUCCESS; } @@ -1559,23 +3094,23 @@ remap_now: static load_return_t get_macho_vnode( - char *path, - integer_t archbits, - struct mach_header *mach_header, - off_t *file_offset, - off_t *macho_size, - struct macho_data *data, - struct vnode **vpp -) + const char *path, + integer_t archbits, + struct mach_header *mach_header, + off_t *file_offset, + off_t *macho_size, + struct macho_data *data, + struct vnode **vpp + ) { - struct vnode *vp; - vfs_context_t ctx = vfs_context_current(); - proc_t p = vfs_context_proc(ctx); - kauth_cred_t kerncred; - struct nameidata *ndp = &data->__nid; - boolean_t is_fat; - struct fat_arch fat_arch; - int error; + struct vnode *vp; + vfs_context_t ctx = vfs_context_current(); + proc_t p = vfs_context_proc(ctx); + kauth_cred_t kerncred; + struct nameidata *ndp = &data->__nid; + boolean_t is_fat; + struct fat_arch fat_arch; + int error; int resid; union macho_vnode_header *header = &data->__header; off_t fsize = (off_t)0; @@ -1599,7 +3134,7 @@ get_macho_vnode( } else { error = LOAD_FAILURE; } - return(error); + return error; } nameidone(ndp); vp = ndp->ni_vp; @@ -1623,7 +3158,7 @@ get_macho_vnode( } /* check access */ - if ((error = vnode_authorize(vp, NULL, KAUTH_VNODE_EXECUTE, ctx)) != 0) { + if ((error = vnode_authorize(vp, NULL, KAUTH_VNODE_EXECUTE | KAUTH_VNODE_READ_DATA, ctx)) != 0) { error = LOAD_PROTECT; goto bad1; } @@ -1634,17 +3169,21 @@ get_macho_vnode( goto bad1; } - if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)header, sizeof (*header), 0, + if ((error = vn_rdwr(UIO_READ, vp, (caddr_t)header, sizeof(*header), 0, UIO_SYSSPACE, IO_NODELOCKED, kerncred, &resid, p)) != 0) { error = LOAD_IOERROR; goto bad2; } + if (resid) { + error = LOAD_BADMACHO; + goto bad2; + } + if (header->mach_header.magic == MH_MAGIC || header->mach_header.magic == MH_MAGIC_64) { is_fat = FALSE; - } else if (header->fat_header.magic == FAT_MAGIC || - header->fat_header.magic == FAT_CIGAM) { + } else if (OSSwapBigToHostInt32(header->fat_header.magic) == FAT_MAGIC) { is_fat = TRUE; } else { error = LOAD_BADMACHO; @@ -1652,21 +3191,33 @@ get_macho_vnode( } if (is_fat) { + error = fatfile_validate_fatarches((vm_offset_t)(&header->fat_header), + sizeof(*header)); + if (error != LOAD_SUCCESS) { + goto bad2; + } + /* Look up our architecture in the fat file. */ - error = fatfile_getarch_with_bits(vp, archbits, - (vm_offset_t)(&header->fat_header), &fat_arch); - if (error != LOAD_SUCCESS) + error = fatfile_getarch_with_bits(archbits, + (vm_offset_t)(&header->fat_header), sizeof(*header), &fat_arch); + if (error != LOAD_SUCCESS) { goto bad2; + } /* Read the Mach-O header out of it */ error = vn_rdwr(UIO_READ, vp, (caddr_t)&header->mach_header, - sizeof (header->mach_header), fat_arch.offset, + sizeof(header->mach_header), fat_arch.offset, UIO_SYSSPACE, IO_NODELOCKED, kerncred, &resid, p); if (error) { error = LOAD_IOERROR; goto bad2; } + if (resid) { + error = LOAD_BADMACHO; + goto bad2; + } + /* Is this really a Mach-O? */ if (header->mach_header.magic != MH_MAGIC && header->mach_header.magic != MH_MAGIC_64) { @@ -1700,11 +3251,11 @@ get_macho_vnode( *vpp = vp; ubc_setsize(vp, fsize); - return (error); + return error; bad2: (void) VNOP_CLOSE(vp, FREAD, ctx); bad1: vnode_put(vp); - return(error); + return error; }