X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/6d2010ae8f7a6078e10b361c6962983bab233e0f..4d15aeb193b2c68f1d38666c317f8d3734f5f083:/bsd/kern/mach_loader.c diff --git a/bsd/kern/mach_loader.c b/bsd/kern/mach_loader.c index ab26c40b9..ca2fb4338 100644 --- a/bsd/kern/mach_loader.c +++ b/bsd/kern/mach_loader.c @@ -49,6 +49,10 @@ #include #include #include +#include +#include +#include +#include #include #include /* vm_allocate() */ @@ -79,24 +83,16 @@ #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(ledger_t ledger, vm_map_size_t size, + boolean_t is_64bit); /* XXX should have prototypes in a shared header file */ extern int get_map_nentries(vm_map_t); @@ -105,21 +101,30 @@ 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, + .is64bit = 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 }; /* @@ -135,7 +140,10 @@ parse_machfile( off_t macho_size, int depth, int64_t slide, - load_result_t *result + int64_t dyld_slide, + load_result_t *result, + load_result_t *binresult, + struct image_params *imgp ); static load_return_t @@ -151,6 +159,13 @@ load_segment( 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_code_signature( struct linkedit_data_command *lcp, @@ -158,7 +173,8 @@ load_code_signature( off_t macho_offset, off_t macho_size, cpu_type_t cputype, - load_result_t *result); + load_result_t *result, + struct image_params *imgp); #if CONFIG_CODE_DECRYPTION static load_return_t @@ -166,9 +182,22 @@ set_code_unprotect( struct encryption_info_command *lcp, caddr_t addr, vm_map_t map, - struct vnode *vp); + 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 load_unixthread( struct thread_command *tcp, @@ -181,16 +210,18 @@ static load_return_t load_threadstate( thread_t thread, uint32_t *ts, - uint32_t total_size + uint32_t total_size, + load_result_t * ); static load_return_t load_threadstack( thread_t thread, - uint32_t *ts, - uint32_t total_size, + uint32_t *ts, + uint32_t total_size, mach_vm_offset_t *user_stack, - int *customstack + int *customstack, + load_result_t *result ); static load_return_t @@ -205,11 +236,12 @@ static load_return_t load_dylinker( struct dylinker_command *lcp, integer_t archbits, - vm_map_t map, - thread_t thread, - int depth, + vm_map_t map, + thread_t thread, + int depth, int64_t slide, - load_result_t *result + load_result_t *result, + struct image_params *imgp ); struct macho_data; @@ -270,62 +302,64 @@ note_all_image_info_section(const struct segment_command_64 *scp, } } + load_return_t load_machfile( struct image_params *imgp, struct mach_header *header, thread_t thread, - vm_map_t new_map, + 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; - + off_t file_size = imgp->ip_vattr->va_data_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); + 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; + mach_vm_offset_t dyld_aslr_offset = 0; kern_return_t kret; - if (new_map == VM_MAP_NULL) { - create_map = TRUE; - old_task = current_task(); + 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. - */ - if (spawn) { - create_map = TRUE; - old_task = get_threadtask(thread); - } + result->is64bit = ((imgp->ip_flags & IMGPF_IS_64BIT) == IMGPF_IS_64BIT); - 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); + task_t ledger_task; + if (imgp->ip_new_thread) { + ledger_task = get_threadtask(imgp->ip_new_thread); + } else { + ledger_task = task; + } + pmap = pmap_create(get_task_ledger(ledger_task), + (vm_map_size_t) 0, + result->is64bit); + map = vm_map_create(pmap, + 0, + vm_compute_max_offset(result->is64bit), + TRUE); - } else - map = new_map; +#if (__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 */ - if ( (header->flags & MH_ALLOW_STACK_EXECUTION) ) + /* 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 ( !cs_enforcement(NULL) && (header->flags & MH_ALLOW_STACK_EXECUTION) ) vm_map_disable_NX(map); #endif @@ -335,12 +369,20 @@ load_machfile( 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)) { + uint64_t max_slide_pages; + + max_slide_pages = vm_map_get_max_aslr_slide_pages(map); + aslr_offset = random(); - aslr_offset %= 1 << ((imgp->ip_flags & IMGPF_IS_64BIT) ? 16 : 8); - aslr_offset <<= PAGE_SHIFT; + aslr_offset %= max_slide_pages; + aslr_offset <<= vm_map_page_shift(map); + + dyld_aslr_offset = random(); + dyld_aslr_offset %= max_slide_pages; + dyld_aslr_offset <<= vm_map_page_shift(map); } if (!result) @@ -348,66 +390,96 @@ load_machfile( *result = load_result_null; + /* + * re-set the bitness on the load result since we cleared the load result above. + */ + result->is64bit = ((imgp->ip_flags & IMGPF_IS_64BIT) == IMGPF_IS_64BIT); + lret = parse_machfile(vp, map, thread, header, file_offset, macho_size, - 0, (int64_t)aslr_offset, result); + 0, (int64_t)aslr_offset, (int64_t)dyld_aslr_offset, result, + NULL, imgp); if (lret != LOAD_SUCCESS) { - if (create_map) { - vm_map_deallocate(map); /* will lose pmap reference too */ - } + 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->is64bit) { + enforce_hard_pagezero = FALSE; + } +#endif /* - * 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)) { + { + 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 (create_map) { + if (in_exec) { /* - * 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. + * 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). */ - 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). - */ - kret = task_start_halt(task); - if (kret != KERN_SUCCESS) { - return(kret); - } - proc_transcommit(current_proc(), 0); - task_complete_halt(task); - workqueue_exit(current_proc()); + kret = task_start_halt(task); + if (kret != KERN_SUCCESS) { + vm_map_deallocate(map); /* will lose pmap reference too */ + return (LOAD_FAILURE); } - old_map = swap_task_map(old_task, thread, map, !spawn); - vm_map_clear_4GB_pagezero(old_map); - vm_map_deallocate(old_map); + proc_transcommit(p, 0); + workqueue_mark_exiting(p); + task_complete_halt(task); + workqueue_exit(p); + kqueue_dealloc(p->p_wqkqueue); + p->p_wqkqueue = NULL; + /* + * 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. + */ + task_rollup_accounting_info(get_threadtask(thread), task); } + *mapp = map; 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 @@ -430,13 +502,15 @@ parse_machfile( off_t macho_size, int depth, int64_t aslr_offset, - load_result_t *result + 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; @@ -448,11 +522,16 @@ parse_machfile( int pass; proc_t p = current_proc(); /* XXXX */ int error; - int resid=0; + int resid = 0; 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; 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 (header->magic == MH_MAGIC_64 || header->magic == MH_CIGAM_64) { @@ -462,7 +541,7 @@ parse_machfile( /* * Break infinite recursion */ - if (depth > 6) { + if (depth > 1) { return(LOAD_FAILURE); } @@ -471,7 +550,7 @@ parse_machfile( /* * Check to see if right machine type. */ - if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != cpu_type()) || + if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != (cpu_type() & ~CPU_ARCH_MASK)) || !grade_binary(header->cputype, header->cpusubtype & ~CPU_SUBTYPE_MASK)) return(LOAD_BADARCH); @@ -480,25 +559,17 @@ parse_machfile( switch (header->filetype) { - case MH_OBJECT: case MH_EXECUTE: - case MH_PRELOAD: if (depth != 1) { return (LOAD_FAILURE); } - break; - - case MH_FVMLIB: - case MH_DYLIB: - if (depth == 1) { - return (LOAD_FAILURE); - } - break; + break; case MH_DYLINKER: if (depth != 2) { return (LOAD_FAILURE); } + is_dyld = TRUE; break; default: @@ -537,33 +608,71 @@ parse_machfile( error = vn_rdwr(UIO_READ, vp, addr, size, file_offset, UIO_SYSSPACE, 0, kauth_cred_get(), &resid, p); if (error) { - if (kl_addr ) + if (kl_addr) kfree(kl_addr, kl_size); return(LOAD_IOERROR); } + if (resid) { + /* We must be able to read in as much as the mach_header indicated */ + if (kl_addr) + kfree(kl_addr, kl_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; + + 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 (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)) { + if ((pass == 3) && (!result->using_lcmain && result->validentry == 0)) { thread_state_initialize(thread); ret = LOAD_FAILURE; break; } -#endif + + /* + * 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; + } /* * Loop through each of the load_commands indicated by the @@ -602,20 +711,112 @@ parse_machfile( * intervention is required. */ switch(lcp->cmd) { - case LC_SEGMENT: - case LC_SEGMENT_64: + case LC_SEGMENT: { + struct segment_command *scp = (struct segment_command *) lcp; + + 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; + } + } + + 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); + 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 (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); + + 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) break; @@ -625,6 +826,17 @@ parse_machfile( 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) break; @@ -637,8 +849,9 @@ 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 + mach_header_sz + header->sizeofcmds, + result); } break; case LC_CODE_SIGNATURE: @@ -655,31 +868,93 @@ parse_machfile( 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 */ + /* + * Allow injections to be ignored on devices w/o enforcement enabled + */ + if (!cs_enforcement(NULL)) + 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 < 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_enforcement(NULL) || + (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: + 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 + /* + * 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); + } + + assert(load_failure_reason != OS_REASON_NULL); + psignal_with_reason(p, SIGKILL, load_failure_reason); } break; #endif @@ -694,42 +969,73 @@ parse_machfile( 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 (ret == LOAD_SUCCESS) { + if (! got_code_signatures) { + if (cs_enforcement(NULL)) { + ret = LOAD_FAILURE; + } else { + /* + * No embedded signatures: look for detached by taskgated, + * this is only done on OSX, on embedded platforms we expect everything + * to be have embedded signatures. + */ + struct cs_blob *blob; + + blob = ubc_cs_blob_get(vp, -1, file_offset); + if (blob != NULL) { + unsigned int cs_flag_data = blob->csb_flags; + if(0 != ubc_cs_generation_check(vp)) { + if (0 != ubc_cs_blob_revalidate(vp, blob, imgp, 0)) { + /* clear out the flag data if revalidation fails */ + cs_flag_data = 0; + result->csflags &= ~CS_VALID; + } + } + /* get flags to be applied to the process */ + result->csflags |= cs_flag_data; + } + } + } - if(depth == 1) { - if (result->thread_count == 0) { + /* Make sure if we need dyld, we got it */ + if (result->needs_dynlinker && !dlp) { ret = LOAD_FAILURE; } + + if ((ret == LOAD_SUCCESS) && (dlp != 0)) { + /* + * load the dylinker, and slide it by the independent DYLD ASLR + * offset regardless of the PIE-ness of the main binary. + */ + ret = load_dylinker(dlp, dlarchbits, map, thread, depth, + dyld_aslr_offset, result, imgp); + } + + if ((ret == LOAD_SUCCESS) && (depth == 1)) { + if (result->thread_count == 0) { + ret = LOAD_FAILURE; + } } } - if (kl_addr ) + if (ret == LOAD_BADMACHO && found_xhdr) { + ret = LOAD_BADMACHO_UPX; + } + + if (kl_addr) { kfree(kl_addr, kl_size); + } return(ret); } #if CONFIG_CODE_DECRYPTION -#define APPLE_UNPROTECTED_HEADER_SIZE (3 * PAGE_SIZE_64) +#define APPLE_UNPROTECTED_HEADER_SIZE (3 * 4096) static load_return_t -unprotect_segment( +unprotect_dsmos_segment( uint64_t file_off, uint64_t file_size, struct vnode *vp, @@ -769,9 +1075,32 @@ unprotect_segment( 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); } @@ -782,7 +1111,7 @@ unprotect_segment( } #else /* CONFIG_CODE_DECRYPTION */ static load_return_t -unprotect_segment( +unprotect_dsmos_segment( __unused uint64_t file_off, __unused uint64_t file_size, __unused struct vnode *vp, @@ -795,29 +1124,166 @@ unprotect_segment( } #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) +{ + int extra_vm_flags, cur_extra_vm_flags; + vm_map_offset_t cur_offset, cur_start, cur_end; + kern_return_t ret; + vm_map_offset_t effective_page_mask; + + 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)); + + extra_vm_flags = 0; + 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 { + 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); + } + + cur_offset = 0; + cur_start = vm_start; + cur_end = vm_start; + 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_extra_vm_flags = extra_vm_flags; + } else { + /* regular mapping for the middle */ + cur_extra_vm_flags = 0; + } + cur_end = vm_map_trunc_page(vm_start + (file_end - + file_start), + effective_page_mask); + if (control != MEMORY_OBJECT_CONTROL_NULL) { + ret = vm_map_enter_mem_object_control( + map, + &cur_start, + cur_end - cur_start, + (mach_vm_offset_t)0, + VM_FLAGS_FIXED | cur_extra_vm_flags, + 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_extra_vm_flags, + 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; +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 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; - mach_vm_offset_t map_addr, map_offset; - mach_vm_size_t map_size, seg_size, delta_size; + 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; + + 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); @@ -829,43 +1295,80 @@ load_segment( 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); } + 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) + 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) + 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) + file_offset = pager_offset + scp->fileoff; /* limited to 32 bits */ + file_size = scp->filesize; + 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); + } /* - * Round sizes to page size. + * If we have a code signature attached for this slice + * require that the segments are within the signed part + * of the file. */ - 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 && + 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; + } + + vm_offset = scp->vmaddr + slide; + 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) { /* @@ -874,65 +1377,96 @@ load_segment( * 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) { - /* - * 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. - */ - ret = vm_map_raise_min_offset(map, seg_size); - if (ret != KERN_SUCCESS) { - return (LOAD_FAILURE); - } - return (LOAD_SUCCESS); + /* + * 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)); } + { + 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 (ret != KERN_SUCCESS) { + return (LOAD_FAILURE); + } + return (LOAD_SUCCESS); + } else { } - /* If a non-zero slide was specified by the caller, apply now */ - map_addr += slide; + { + 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 (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; + 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); - map_offset = pager_offset + scp->fileoff; /* limited to 32 bits */ - - if (map_size > 0) { + 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. */ - 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 (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); + 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 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) + ret = mach_vm_allocate(kernel_map, &tmp, delta_size, VM_FLAGS_ANYWHERE| VM_MAKE_TAG(VM_KERN_MEMORY_BSD)); + if (ret != KERN_SUCCESS) { return(LOAD_RESOURCE); + } if (copyout(tmp, map_addr + scp->filesize, delta_size)) { @@ -951,44 +1485,174 @@ load_segment( * than the size from the file, we need to allocate * zero fill memory for the rest. */ - delta_size = seg_size - map_size; + 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 = map_addr + map_size; - - 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) + 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); + if (kr != KERN_SUCCESS) { return(LOAD_NOSPACE); + } } if ( (scp->fileoff == 0) && (scp->filesize != 0) ) - result->mach_header = map_addr; + result->mach_header = vm_offset; if (scp->flags & SG_PROTECTED_VERSION_1) { - ret = unprotect_segment(scp->fileoff, - scp->filesize, - vp, - pager_offset, - map, - map_addr, - map_size); + 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) + + 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); + 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; + 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_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); + + /* + * LC_MAIN specifies stack size but not location. + * Add guard page to allocation size (MAXSSIZ includes guard page). + */ + if (epc->stacksize) { + if (os_add_overflow(epc->stacksize, 4*PAGE_SIZE, &result->user_stack_size)) { + /* + * 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 + */ + 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; + } + } else { + result->user_stack_alloc_size = MAXSSIZ; + } + + /* use default location for stack */ + ret = thread_userstackdefault(&addr, result->is64bit); + if (ret != KERN_SUCCESS) + return(LOAD_FAILURE); + + /* The stack slides down from the default location */ + result->user_stack = addr; + result->user_stack -= slide; + + if (result->using_lcmain || result->entry_point != MACH_VM_MIN_ADDRESS) { + /* Already processed LC_MAIN or LC_UNIXTHREAD */ + return (LOAD_FAILURE); + } + + /* kernel does *not* use entryoff from LC_MAIN. Dyld uses it. */ + result->needs_dynlinker = TRUE; + result->using_lcmain = 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( @@ -1000,11 +1664,11 @@ load_unixthread( { 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); } @@ -1015,32 +1679,40 @@ load_unixthread( (uint32_t *)(((vm_offset_t)tcp) + sizeof(struct thread_command)), tcp->cmdsize - sizeof(struct thread_command), - &result->user_stack, - &customstack); + &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 */ + + if (!customstack) { + result->user_stack_alloc_size = MAXSSIZ; + } - result->user_stack += slide; + /* 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); + &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)); + (uint32_t *)(((vm_offset_t)tcp) + sizeof(struct thread_command)), + tcp->cmdsize - sizeof(struct thread_command), + result); if (ret != LOAD_SUCCESS) return (ret); @@ -1055,55 +1727,68 @@ load_return_t load_threadstate( thread_t thread, uint32_t *ts, - uint32_t total_size + uint32_t total_size, + load_result_t *result ) { - kern_return_t ret; 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; + } - ret = thread_state_initialize( thread ); - if (ret != KERN_SUCCESS) { - return(LOAD_FAILURE); - } - /* - * 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 *) */ } - return(LOAD_SUCCESS); + + result->threadstate = local_ts; + result->threadstate_sz = local_ts_size; + return LOAD_SUCCESS; + +bad: + if (local_ts) { + kfree(local_ts, local_ts_size); + } + return ret; } static load_return_t load_threadstack( - thread_t thread, - uint32_t *ts, - uint32_t total_size, + thread_t thread, + uint32_t *ts, + uint32_t total_size, mach_vm_offset_t *user_stack, - int *customstack + int *customstack, + load_result_t *result ) { kern_return_t ret; @@ -1127,7 +1812,7 @@ 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->is64bit); if (ret != KERN_SUCCESS) { return(LOAD_FAILURE); } @@ -1187,6 +1872,13 @@ struct macho_data { } __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, @@ -1195,7 +1887,8 @@ load_dylinker( thread_t thread, int depth, int64_t slide, - load_result_t *result + load_result_t *result, + struct image_params *imgp ) { char *name; @@ -1217,6 +1910,7 @@ load_dylinker( return (LOAD_BADMACHO); name = (char *)lcp + lcp->name.offset; + /* * Check for a proper null terminated string. */ @@ -1226,6 +1920,35 @@ load_dylinker( return(LOAD_BADMACHO); } while (*p++); +#if (DEVELOPMENT || DEBUG) + + /* + * 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. + */ + + 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); @@ -1239,84 +1962,29 @@ load_dylinker( 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->is64bit = result->is64bit; 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; - - 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; + macho_size, depth, slide, 0, myresult, result, imgp); - 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: + vnode_put(vp); novp_out: FREE(dyld_data, M_TEMP); @@ -1331,7 +1999,8 @@ load_code_signature( off_t macho_offset, off_t macho_size, cpu_type_t cputype, - load_result_t *result) + load_result_t *result, + struct image_params *imgp) { int ret; kern_return_t kr; @@ -1350,13 +2019,18 @@ load_code_signature( 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 */ + blob->csb_base_offset == macho_offset) { + /* it matches the blob we want here, lets verify the version */ + if(0 != ubc_cs_generation_check(vp)) { + if (0 != ubc_cs_blob_revalidate(vp, blob, imgp, 0)) { + ret = LOAD_FAILURE; /* set error same as from ubc_cs_blob_add */ + goto out; + } + } ret = LOAD_SUCCESS; } else { /* the blob has changed for this vnode: fail ! */ @@ -1391,8 +2065,14 @@ load_code_signature( if (ubc_cs_blob_add(vp, cputype, macho_offset, - addr, - lcp->datasize)) { + &addr, + lcp->datasize, + imgp, + 0, + &blob)) { + if (addr) { + ubc_cs_blob_deallocate(addr, blob_size); + } ret = LOAD_FAILURE; goto out; } else { @@ -1404,12 +2084,15 @@ load_code_signature( 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("sucess, 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); @@ -1424,12 +2107,16 @@ 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; @@ -1438,6 +2125,7 @@ set_code_unprotect( 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; @@ -1465,20 +2153,36 @@ set_code_unprotect( 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) { printf("set_code_unprotect: unable to create decrypter %s, kr=%d\n", cryptname, kr); - return LOAD_RESOURCE; + 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 @@ -1505,8 +2209,9 @@ set_code_unprotect( if ((seg64->fileoff <= eip->cryptoff) && (seg64->fileoff+seg64->filesize >= eip->cryptoff+eip->cryptsize)) { - map_offset = seg64->vmaddr + eip->cryptoff - seg64->fileoff; + 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: @@ -1514,8 +2219,9 @@ set_code_unprotect( if ((seg32->fileoff <= eip->cryptoff) && (seg32->fileoff+seg32->filesize >= eip->cryptoff+eip->cryptsize)) { - map_offset = seg32->vmaddr + eip->cryptoff - seg32->fileoff; + map_offset = seg32->vmaddr + eip->cryptoff - seg32->fileoff + slide; map_size = eip->cryptsize; + crypto_backing_offset = macho_offset + eip->cryptoff; goto remap_now; } } @@ -1526,10 +2232,16 @@ set_code_unprotect( 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; } @@ -1611,7 +2323,7 @@ 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; } @@ -1628,21 +2340,32 @@ get_macho_vnode( 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) { - is_fat = TRUE; + } else if (OSSwapBigToHostInt32(header->fat_header.magic) == FAT_MAGIC) { + is_fat = TRUE; } else { error = LOAD_BADMACHO; goto bad2; } 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); + error = fatfile_getarch_with_bits(archbits, + (vm_offset_t)(&header->fat_header), sizeof(*header), &fat_arch); if (error != LOAD_SUCCESS) goto bad2; @@ -1655,6 +2378,11 @@ get_macho_vnode( 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) {