This is xnu-10002.1.13. See this file in:
/*
* Copyright (c) 2000-2020 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
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* 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,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* 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@
*/
/*
* Copyright (C) 1988, 1989, NeXT, Inc.
*
* File: kern/mach_loader.c
* Author: Avadis Tevanian, Jr.
*
* Mach object file loader (kernel version, for now).
*
* 21-Jul-88 Avadis Tevanian, Jr. (avie) at NeXT
* Started.
*/
#include <sys/param.h>
#include <sys/vnode_internal.h>
#include <sys/uio.h>
#include <sys/namei.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <sys/stat.h>
#include <sys/malloc.h>
#include <sys/mount_internal.h>
#include <sys/fcntl.h>
#include <sys/file_internal.h>
#include <sys/ubc_internal.h>
#include <sys/imgact.h>
#include <sys/codesign.h>
#include <sys/proc_uuid_policy.h>
#include <sys/reason.h>
#include <sys/kdebug.h>
#include <sys/spawn_internal.h>
#include <mach/mach_types.h>
#include <mach/vm_map.h> /* vm_allocate() */
#include <mach/mach_vm.h> /* mach_vm_allocate() */
#include <mach/vm_statistics.h>
#include <mach/task.h>
#include <mach/thread_act.h>
#include <machine/vmparam.h>
#include <machine/exec.h>
#include <machine/pal_routines.h>
#include <kern/ast.h>
#include <kern/kern_types.h>
#include <kern/cpu_number.h>
#include <kern/mach_loader.h>
#include <kern/mach_fat.h>
#include <kern/kalloc.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/page_decrypt.h>
#include <mach-o/fat.h>
#include <mach-o/loader.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_pager.h>
#include <vm/vnode_pager.h>
#include <vm/vm_protos.h>
#include <vm/vm_shared_region.h>
#include <IOKit/IOReturn.h> /* for kIOReturnNotPrivileged */
#include <IOKit/IOBSD.h> /* for IOVnodeHasEntitlement */
#include <os/log.h>
#include <os/overflow.h>
#include "kern_exec_internal.h"
/* XXX should have prototypes in a shared header file */
extern int get_map_nentries(vm_map_t);
extern kern_return_t memory_object_signed(memory_object_control_t control,
boolean_t is_signed);
/* An empty load_result_t */
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,
.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,
.ro_vm_start = MACH_VM_MIN_ADDRESS,
.ro_vm_end = MACH_VM_MIN_ADDRESS,
.cs_end_offset = 0,
.threadstate = NULL,
.threadstate_sz = 0,
.is_rosetta = 0,
.dynlinker_ro_vm_start = 0,
.dynlinker_ro_vm_end = 0,
.dynlinker_mach_header = MACH_VM_MIN_ADDRESS,
.dynlinker_fd = -1,
};
/*
* Prototypes of static functions.
*/
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,
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 image_params *imgp
);
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,
struct image_params *imgp,
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,
cpu_subtype_t cpusubtype,
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,
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,
boolean_t is_x86_64_compat_binary,
load_result_t *result
);
static load_return_t
load_threadstate(
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,
boolean_t is_x86_64_compat_binary,
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
);
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 image_params *imgp
);
#if CONFIG_ROSETTA
static load_return_t
load_rosetta(
vm_map_t map,
thread_t thread,
load_result_t *result,
struct image_params *imgp
);
#endif
#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(
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,
struct image_params *imgp
);
static inline void
widen_segment_command(const struct segment_command *scp32,
struct segment_command_64 *scp)
{
scp->cmd = scp32->cmd;
scp->cmdsize = scp32->cmdsize;
bcopy(scp32->segname, scp->segname, sizeof(scp->segname));
scp->vmaddr = scp32->vmaddr;
scp->vmsize = scp32->vmsize;
scp->fileoff = scp32->fileoff;
scp->filesize = scp32->filesize;
scp->maxprot = scp32->maxprot;
scp->initprot = scp32->initprot;
scp->nsects = scp32->nsects;
scp->flags = scp32->flags;
}
static void
note_all_image_info_section(const struct segment_command_64 *scp,
boolean_t is64, size_t section_size, const void *sections,
int64_t slide, load_result_t *result)
{
const union {
struct section s32;
struct section_64 s64;
} *sectionp;
unsigned int i;
if (strncmp(scp->segname, "__DATA_DIRTY", sizeof(scp->segname)) != 0 &&
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);
if (0 == strncmp(sectionp->s64.sectname, "__all_image_info",
sizeof(sectionp->s64.sectname))) {
result->all_image_info_addr =
is64 ? sectionp->s64.addr : sectionp->s32.addr;
result->all_image_info_addr += slide;
result->all_image_info_size =
is64 ? sectionp->s64.size : sectionp->s32.size;
return;
}
}
}
#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__ */
#if __has_feature(ptrauth_calls) && XNU_TARGET_OS_OSX
/**
* Determines whether this is an arm64e process which may host in-process
* plugins.
*/
static inline bool
arm64e_plugin_host(struct image_params *imgp, load_result_t *result)
{
if (imgp->ip_flags & IMGPF_NOJOP) {
return false;
}
if (!result->platform_binary) {
return false;
}
struct cs_blob *csblob = csvnode_get_blob(imgp->ip_vp, imgp->ip_arch_offset);
const char *identity = csblob_get_identity(csblob);
if (!identity) {
return false;
}
/* Check if override host plugin entitlement is present and posix spawn attribute to disable A keys is passed */
if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, OVERRIDE_PLUGIN_HOST_ENTITLEMENT)) {
bool ret = imgp->ip_flags & IMGPF_PLUGIN_HOST_DISABLE_A_KEYS;
if (ret) {
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
set_proc_name(imgp, p);
os_log(OS_LOG_DEFAULT, "%s: running binary \"%s\" in keys-off mode due to posix_spawnattr_disable_ptr_auth_a_keys_np", __func__, p->p_name);
}
return ret;
}
/* Disabling library validation is a good signal that this process plans to host plugins */
const char *const disable_lv_entitlements[] = {
"com.apple.security.cs.disable-library-validation",
"com.apple.private.cs.automator-plugins",
CLEAR_LV_ENTITLEMENT,
};
for (size_t i = 0; i < ARRAY_COUNT(disable_lv_entitlements); i++) {
const char *entitlement = disable_lv_entitlements[i];
if (IOVnodeHasEntitlement(imgp->ip_vp, (int64_t)imgp->ip_arch_offset, entitlement)) {
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
set_proc_name(imgp, p);
os_log(OS_LOG_DEFAULT, "%s: running binary \"%s\" in keys-off mode due to entitlement: %s", __func__, p->p_name, entitlement);
return true;
}
}
/* From /System/Library/Security/HardeningExceptions.plist */
const char *const hardening_exceptions[] = {
"com.apple.perl5", /* Scripting engines may load third party code and jit*/
"com.apple.perl", /* Scripting engines may load third party code and jit*/
"org.python.python", /* Scripting engines may load third party code and jit*/
"com.apple.expect", /* Scripting engines may load third party code and jit*/
"com.tcltk.wish", /* Scripting engines may load third party code and jit*/
"com.tcltk.tclsh", /* Scripting engines may load third party code and jit*/
"com.apple.ruby", /* Scripting engines may load third party code and jit*/
"com.apple.bash", /* Required for the 'enable' command */
"com.apple.zsh", /* Required for the 'zmodload' command */
"com.apple.ksh", /* Required for 'builtin' command */
};
for (size_t i = 0; i < ARRAY_COUNT(hardening_exceptions); i++) {
if (strncmp(hardening_exceptions[i], identity, strlen(hardening_exceptions[i])) == 0) {
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
set_proc_name(imgp, p);
os_log(OS_LOG_DEFAULT, "%s: running binary \"%s\" in keys-off mode due to identity: %s", __func__, p->p_name, identity);
return true;
}
}
return false;
}
#endif /* __has_feature(ptrauth_calls) && XNU_TARGET_OS_OSX */
load_return_t
load_machfile(
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;
off_t total_size = 0;
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();
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 (os_add_overflow(file_offset, macho_size, &total_size) ||
total_size > file_size) {
return LOAD_BADMACHO;
}
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) */
#if CONFIG_ROSETTA
pmap_flags |= (imgp->ip_flags & IMGPF_ROSETTA) ? PMAP_CREATE_ROSETTA : 0;
#endif
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;
}
#if XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGES
if (imgp->ip_px_sa != NULL) {
struct _posix_spawnattr* psa = (struct _posix_spawnattr *) imgp->ip_px_sa;
if (psa->psa_flags & _POSIX_SPAWN_FORCE_4K_PAGES) {
pmap_flags |= PMAP_CREATE_FORCE_4K_PAGES;
}
}
#endif /* XNU_TARGET_OS_OSX && _POSIX_SPAWN_FORCE_4K_PAGES && PMAP_CREATE_FORCE_4K_PAGE */
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_options(pmap, 0,
vm_compute_max_offset(result->is_64bit_addr),
VM_MAP_CREATE_PAGEABLE);
#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);
}
#endif /* __arm64__ */
#if PMAP_CREATE_FORCE_4K_PAGES
if (pmap_flags & PMAP_CREATE_FORCE_4K_PAGES) {
DEBUG4K_LIFE("***** launching '%s' as 4k *****\n", vp->v_name);
vm_map_set_page_shift(map, FOURK_PAGE_SHIFT);
}
#endif /* PMAP_CREATE_FORCE_4K_PAGES */
#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 (!cs_process_global_enforcement() && (header->flags & MH_ALLOW_STACK_EXECUTION)) {
vm_map_disable_NX(map);
// TODO: Message Trace or log that this is happening
}
#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)) {
vm_map_disallow_data_exec(map);
}
/*
* Compute a random offset for ASLR, and an independent random offset for dyld.
*/
if (!(imgp->ip_flags & IMGPF_DISABLE_ASLR)) {
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 = (aslr_page_offset % (vm_map_get_max_aslr_slide_pages(map) - 1)) + 1;
aslr_page_offset <<= vm_map_page_shift(map);
dyld_aslr_page_offset = random();
dyld_aslr_page_offset = (dyld_aslr_page_offset %
(vm_map_get_max_loader_aslr_slide_pages(map) - 1)) + 1;
dyld_aslr_page_offset <<= vm_map_page_shift(map);
aslr_page_offset += aslr_section_offset;
}
if (vm_map_page_shift(map) < (int)PAGE_SHIFT) {
DEBUG4K_LOAD("slide=0x%llx dyld_slide=0x%llx\n", aslr_page_offset, dyld_aslr_page_offset);
}
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, aslr_page_offset, dyld_aslr_page_offset, result,
NULL, imgp);
if (lret != LOAD_SUCCESS) {
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__ */
/*
* 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 __arm64__
if (enforce_hard_pagezero && result->is_64bit_addr && (header->cputype == CPU_TYPE_ARM64)) {
/* 64 bit ARM binary must have "hard page zero" of 4GB to cover the lower 32 bit address space */
if (vm_map_has_hard_pagezero(map, 0x100000000) == FALSE) {
vm_map_deallocate(map); /* will lose pmap reference too */
return LOAD_BADMACHO;
}
}
#endif
vm_commit_pagezero_status(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.
*/
if (in_exec) {
proc_t p = current_proc();
/*
* 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);
/*
* 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;
#if __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX)
/*
* arm64e plugin hosts currently run with JOP keys disabled, since they
* may need to run arm64 plugins.
*/
if (arm64e_plugin_host(imgp, result)) {
imgp->ip_flags |= IMGPF_NOJOP;
pmap_disable_user_jop(pmap);
}
#if CONFIG_ROSETTA
/* Disable JOP keys if the Rosetta runtime being used isn't arm64e */
if (result->is_rosetta && (imgp->ip_flags & IMGPF_NOJOP)) {
pmap_disable_user_jop(pmap);
}
#endif /* CONFIG_ROSETTA */
#endif /* __has_feature(ptrauth_calls) && defined(XNU_TARGET_OS_OSX) */
return LOAD_SUCCESS;
}
int macho_printf = 0;
#define MACHO_PRINTF(args) \
do { \
if (macho_printf) { \
printf args; \
} \
} while (0)
static boolean_t
pie_required(
cpu_type_t exectype,
cpu_subtype_t execsubtype)
{
switch (exectype) {
case CPU_TYPE_X86_64:
return FALSE;
case CPU_TYPE_ARM64:
return TRUE;
case CPU_TYPE_ARM:
switch (execsubtype) {
case CPU_SUBTYPE_ARM_V7K:
return TRUE;
}
break;
}
return FALSE;
}
/*
* 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
* the contents of its sizeofcmds, which is currently constrained to 32
* bits in the file format itself. We read into the kernel buffer the
* commands section, and then parse it in order to parse the mach-o file
* format load_command segment(s). We are only interested in a subset of
* the total set of possible commands. If "map"==VM_MAP_NULL or
* "thread"==THREAD_NULL, do not make permament VM modifications,
* just preflight the parse.
*/
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,
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;
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);
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 = PAGE_MASK;
#if __arm64__
uint64_t pagezero_end = 0;
uint64_t executable_end = 0;
uint64_t writable_start = 0;
vm_map_size_t effective_page_size;
effective_page_mask = vm_map_page_mask(map);
effective_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);
}
/*
* Break infinite recursion
*/
if (depth > 2) {
return LOAD_FAILURE;
}
depth++;
/*
* Set CS_NO_UNTRUSTED_HELPERS by default; load_dylinker and load_rosetta
* will unset it if necessary.
*/
if (depth == 1) {
result->csflags |= CS_NO_UNTRUSTED_HELPERS;
}
/*
* Check to see if right machine type.
*/
if (((cpu_type_t)(header->cputype & ~CPU_ARCH_MASK) != (cpu_type() & ~CPU_ARCH_MASK))
) {
return LOAD_BADARCH;
}
if (!grade_binary(header->cputype,
header->cpusubtype & ~CPU_SUBTYPE_MASK,
header->cpusubtype & CPU_SUBTYPE_MASK, TRUE)) {
return LOAD_BADARCH;
}
abi64 = ((header->cputype & CPU_ARCH_ABI64) == CPU_ARCH_ABI64);
switch (header->filetype) {
case MH_EXECUTE:
if (depth != 1 && depth != 3) {
return LOAD_FAILURE;
}
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 if (header->cputype == CPU_TYPE_X86_64) {
/* x86_64 static binaries allowed */
#if CONFIG_ROSETTA
} else if (imgp->ip_flags & IMGPF_ROSETTA) {
/* Rosetta runtime allowed */
#endif /* CONFIG_X86_64_COMPAT */
} else {
/* Check properties of static executables (disallowed except for development) */
#if !(DEVELOPMENT || DEBUG)
return LOAD_FAILURE;
#endif
}
break;
case MH_DYLINKER:
if (depth != 2) {
return LOAD_FAILURE;
}
is_dyld = TRUE;
break;
default:
return LOAD_FAILURE;
}
/*
* For PIE and dyld, slide everything by the ASLR offset.
*/
if ((header->flags & MH_PIE) || is_dyld) {
slide = aslr_offset;
}
/*
* Get the pager for the file.
*/
control = ubc_getobject(vp, UBC_FLAGS_NONE);
/* 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) ||
alloc_size > INT_MAX) {
return LOAD_BADMACHO;
}
/*
* Map the load commands into kernel memory.
*/
addr = kalloc_data(alloc_size, Z_WAITOK);
if (addr == NULL) {
return LOAD_NOSPACE;
}
error = vn_rdwr(UIO_READ, vp, addr, (int)alloc_size, file_offset,
UIO_SYSSPACE, 0, vfs_context_ucred(imgp->ip_vfs_context), &resid, p);
if (error) {
kfree_data(addr, alloc_size);
return LOAD_IOERROR;
}
if (resid) {
{
/* We must be able to read in as much as the mach_header indicated */
kfree_data(addr, alloc_size);
return LOAD_BADMACHO;
}
}
/*
* 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, load platform version
* 1: thread state, uuid, code signature
* 2: segments
* 3: dyld, encryption, check entry point
*/
boolean_t slide_realign = FALSE;
#if __arm64__
if (!abi64) {
slide_realign = TRUE;
}
#endif
for (pass = 0; pass <= 3; pass++) {
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.
*/
mach_vm_address_t max_vm_addr = binresult->max_vm_addr;
slide = vm_map_round_page(slide + max_vm_addr, effective_page_mask);
}
}
/*
* Check that the entry point is contained in an executable segment
*/
if ((pass == 3) && (thread != THREAD_NULL)) {
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;
}
/*
* 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) {
ret = LOAD_BADMACHO;
break;
}
/*
* Get a pointer to the command.
*/
lcp = (struct load_command *)((uintptr_t)addr + offset);
oldoffset = 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) {
ret = LOAD_BADMACHO;
break;
}
/*
* 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: {
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) || pagezero_end > UINT32_MAX) {
ret = LOAD_BADMACHO;
break;
}
}
if (scp->initprot & VM_PROT_EXECUTE) {
/* TEXT */
if (os_add3_overflow(scp->vmaddr, scp->vmsize, slide, &executable_end) || executable_end > UINT32_MAX) {
ret = LOAD_BADMACHO;
break;
}
}
if (scp->initprot & VM_PROT_WRITE) {
/* DATA */
if (os_add_overflow(scp->vmaddr, slide, &writable_start) || writable_start > UINT32_MAX) {
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 <rdar://problem/11021230>
*/
ret = LOAD_BADMACHO;
break;
}
ret = load_segment(lcp,
header->filetype,
control,
file_offset,
macho_size,
vp,
map,
slide,
result,
imgp);
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;
}
/* 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 <rdar://problem/11021230>
*/
ret = LOAD_BADMACHO;
break;
}
ret = load_segment(lcp,
header->filetype,
control,
file_offset,
macho_size,
vp,
map,
slide,
result,
imgp);
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: {
boolean_t is_x86_64_compat_binary = FALSE;
if (pass != 1) {
break;
}
#if CONFIG_ROSETTA
if (depth == 2 && (imgp->ip_flags & IMGPF_ROSETTA)) {
// Ignore dyld, Rosetta will parse it's load commands to get the
// entry point.
result->validentry = 1;
break;
}
#endif
ret = load_unixthread(
(struct thread_command *) lcp,
thread,
slide,
is_x86_64_compat_binary,
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;
}
if ((depth == 1) && (dlp == 0)) {
dlp = (struct dylinker_command *)lcp;
} else {
ret = LOAD_FAILURE;
}
break;
case LC_UUID:
if (pass == 1 && depth == 1) {
ret = load_uuid((struct uuid_command *) lcp,
(char *)addr + cmds_size,
result);
}
break;
case LC_CODE_SIGNATURE:
/* CODE SIGNING */
if (pass != 1) {
break;
}
/* pager -> uip ->
* 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,
header->cpusubtype,
result,
imgp);
if (ret != LOAD_SUCCESS) {
printf("proc %d: load code signature error %d "
"for file \"%s\"\n",
proc_getpid(p), 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,
(const void *)((uintptr_t)addr + off),
MIN(PAGE_SIZE, cmds_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, proc_getpid(p), (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:
case LC_ENCRYPTION_INFO_64:
if (pass != 3) {
break;
}
ret = set_code_unprotect(
(struct encryption_info_command *) lcp,
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",
proc_getpid(p), ret, vp->v_name);
/*
* Don't let the app run if it's
* encrypted but we failed to set up the
* 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,
proc_getpid(p), 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,
proc_getpid(p), 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);
{
psignal_with_reason(current_proc(), 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 != 0) {
break;
}
vmc = (struct version_min_command *) lcp;
ret = load_version(vmc, &found_version_cmd, imgp, result);
#if XNU_TARGET_OS_OSX
if (ret == LOAD_SUCCESS) {
if (result->ip_platform == PLATFORM_IOS) {
vm_map_mark_alien(map);
} else {
assert(!vm_map_is_alien(map));
}
}
#endif /* XNU_TARGET_OS_OSX */
break;
}
case LC_BUILD_VERSION: {
if (depth != 1 || pass != 0) {
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;
result->lr_sdk = bvc->sdk;
result->lr_min_sdk = bvc->minos;
found_version_cmd = TRUE;
#if XNU_TARGET_OS_OSX
if (result->ip_platform == PLATFORM_IOS) {
vm_map_mark_alien(map);
} else {
assert(!vm_map_is_alien(map));
}
#endif /* XNU_TARGET_OS_OSX */
break;
}
default:
/* Other commands are ignored by the kernel */
ret = LOAD_SUCCESS;
break;
}
if (ret != LOAD_SUCCESS) {
break;
}
}
if (ret != LOAD_SUCCESS) {
break;
}
}
if (ret == LOAD_SUCCESS) {
if (!got_code_signatures && cs_process_global_enforcement()) {
ret = LOAD_FAILURE;
}
/* 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, header->cputype, map, thread, depth,
dyld_aslr_offset, result, imgp);
}
#if CONFIG_ROSETTA
if ((ret == LOAD_SUCCESS) && (depth == 1) && (imgp->ip_flags & IMGPF_ROSETTA)) {
ret = load_rosetta(map, thread, result, imgp);
if (ret == LOAD_SUCCESS) {
if (result->user_stack_alloc_size != 0) {
// If a stack allocation is required then add a 4gb gap after the main
// binary/dyld for the worst case static translation size.
mach_vm_size_t reserved_aot_size = 0x100000000;
vm_map_offset_t mask = vm_map_page_mask(map);
mach_vm_address_t vm_end;
if (dlp != 0) {
vm_end = vm_map_round_page(result->dynlinker_max_vm_addr, mask);
} else {
vm_end = vm_map_round_page(result->max_vm_addr, mask);
}
mach_vm_size_t user_stack_size = vm_map_round_page(result->user_stack_alloc_size, mask);
result->user_stack = vm_map_round_page(vm_end + user_stack_size + reserved_aot_size + slide, mask);
}
}
}
#endif
if ((ret == LOAD_SUCCESS) && (depth == 1)) {
if (result->thread_count == 0) {
ret = LOAD_FAILURE;
}
#if CONFIG_ENFORCE_SIGNED_CODE
if (!(result->csflags & CS_NO_UNTRUSTED_HELPERS)) {
ret = LOAD_FAILURE;
}
#endif
}
}
if (ret == LOAD_BADMACHO && found_xhdr) {
ret = LOAD_BADMACHO_UPX;
}
kfree_data(addr, alloc_size);
return ret;
}
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;
}
#if __x86_64__
static boolean_t
check_if_simulator_binary(
struct image_params *imgp,
off_t file_offset,
off_t macho_size)
{
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_data(PAGE_SIZE, Z_WAITOK | Z_ZERO);
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) ||
alloc_size > INT_MAX) {
goto bad;
}
/*
* Map the load commands into kernel memory.
*/
addr = kalloc_data(alloc_size, Z_WAITOK);
if (addr == NULL) {
goto bad;
}
error = vn_rdwr(UIO_READ, imgp->ip_vp, addr, (int)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 *)((uintptr_t)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_data(ip_vdata, PAGE_SIZE);
}
if (cred) {
kauth_cred_unref(&cred);
}
if (addr) {
kfree_data(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;
uint64_t slice_off;
/*
* 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".
*/
slice_off = file_off - macho_offset;
if (slice_off <= APPLE_UNPROTECTED_HEADER_SIZE &&
slice_off + file_size <= APPLE_UNPROTECTED_HEADER_SIZE) {
/* it's all unprotected, nothing to do... */
kr = KERN_SUCCESS;
} else {
if (slice_off <= APPLE_UNPROTECTED_HEADER_SIZE) {
/*
* We start mapping in the unprotected area.
* Skip the unprotected part...
*/
uint64_t delta_file;
vm_map_offset_t delta_map;
delta_file = (uint64_t)APPLE_UNPROTECTED_HEADER_SIZE;
delta_file -= slice_off;
if (os_convert_overflow(delta_file, &delta_map)) {
return LOAD_BADMACHO;
}
if (os_add_overflow(map_addr, delta_map, &map_addr)) {
return LOAD_BADMACHO;
}
if (os_sub_overflow(map_size, delta_map, &map_size)) {
return LOAD_BADMACHO;
}
}
/* ... 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",
proc_getpid(p), 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,
CRYPTID_APP_ENCRYPTION);
}
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 = vm_map_page_mask(map);
vmk_flags = VM_MAP_KERNEL_FLAGS_FIXED();
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,
vmk_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,
vmk_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;
}
#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_FIXED();
}
#if !defined(XNU_TARGET_OS_OSX)
(void) result;
#else /* !defined(XNU_TARGET_OS_OSX) */
/*
* 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 /* !defined(XNU_TARGET_OS_OSX) */
if (result->is_rosetta && (initprot & VM_PROT_EXECUTE) == VM_PROT_EXECUTE) {
cur_vmk_flags.vmkf_translated_allow_execute = TRUE;
}
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,
cur_vmk_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,
cur_vmk_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;
#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,
vmk_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,
vmk_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;
}
#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 image_params *imgp)
{
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;
uint64_t file_offset, file_size;
vm_map_offset_t vm_offset;
size_t 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__
boolean_t fourk_align;
#endif /* __arm64__ */
(void)imgp;
effective_page_size = vm_map_page_size(map);
effective_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;
if (vm_map_page_shift(map) == FOURK_PAGE_SHIFT &&
PAGE_SHIFT != FOURK_PAGE_SHIFT) {
fourk_align = TRUE;
verbose = TRUE;
}
#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) {
DEBUG4K_ERROR("LOAD_BADMACHO cmdsize %d < %zu\n", lcp->cmdsize, segment_command_size);
return LOAD_BADMACHO;
}
total_section_size = lcp->cmdsize - segment_command_size;
if (LC_SEGMENT_64 == lcp->cmd) {
scp = (struct segment_command_64 *)lcp;
} 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) {
DEBUG4K_ERROR("LOAD_BADMACHO fileoff 0x%llx filesize 0x%llx macho_size 0x%llx\n", 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) {
DEBUG4K_ERROR("LOAD_BADMACHO 0x%zx 0x%zx %d\n", total_section_size, single_section_size, scp->nsects);
return LOAD_BADMACHO;
}
/*
* Make sure the segment is page-aligned in the file.
*/
if (os_add_overflow(pager_offset, scp->fileoff, &file_offset)) {
DEBUG4K_ERROR("LOAD_BADMACHO file_offset: 0x%llx + 0x%llx\n", pager_offset, scp->fileoff);
return LOAD_BADMACHO;
}
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
*/
DEBUG4K_ERROR("LOAD_BADMACHO file_offset 0x%llx\n", file_offset);
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.
*/
DEBUG4K_ERROR("LOAD_BADMACHO file_offset 0x%llx\n", file_offset);
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");
}
DEBUG4K_ERROR("LOAD_BADMACHO end_offset 0x%llx fileoff 0x%llx filesize 0x%llx\n", result->cs_end_offset, scp->fileoff, scp->filesize);
return LOAD_BADMACHO;
}
if (os_add_overflow(scp->vmaddr, slide, &vm_offset)) {
if (cs_debug) {
printf("vmaddr too large\n");
}
DEBUG4K_ERROR("LOAD_BADMACHO vmaddr 0x%llx slide 0x%llx vm_offset 0x%llx\n", scp->vmaddr, slide, (uint64_t)vm_offset);
return LOAD_BADMACHO;
}
if (scp->vmsize > SIZE_MAX) {
DEBUG4K_ERROR("LOAD_BADMACHO vmsize 0x%llx\n", scp->vmsize);
return LOAD_BADMACHO;
}
vm_size = (size_t)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) {
if (map == VM_MAP_NULL) {
return LOAD_SUCCESS;
}
/*
* 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_map_offset_t)(vm_offset + vm_size);
if (vm_end < vm_offset) {
DEBUG4K_ERROR("LOAD_BADMACHO vm_end 0x%llx vm_offset 0x%llx vm_size 0x%llx\n", (uint64_t)vm_end, (uint64_t)vm_offset, (uint64_t)vm_size);
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);
ret = vm_map_enter_mem_object(
map,
&vm_end_aligned,
vm_end - vm_end_aligned,
(mach_vm_offset_t) 0, /* mask */
VM_MAP_KERNEL_FLAGS_FIXED(.vmkf_fourk = true),
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) {
DEBUG4K_ERROR("LOAD_FAILURE ret 0x%x\n", ret);
return LOAD_FAILURE;
}
return LOAD_SUCCESS;
} else {
#if !defined(XNU_TARGET_OS_OSX)
/* not PAGEZERO: should not be mapped at address 0 */
if (filetype != MH_DYLINKER && (imgp->ip_flags & IMGPF_ROSETTA) == 0 && scp->vmaddr == 0) {
DEBUG4K_ERROR("LOAD_BADMACHO filetype %d vmaddr 0x%llx\n", filetype, scp->vmaddr);
return LOAD_BADMACHO;
}
#endif /* !defined(XNU_TARGET_OS_OSX) */
}
#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 (file_offset - file_start > FOURK_PAGE_MASK ||
file_end - file_offset - file_size > FOURK_PAGE_MASK) {
DEBUG4K_ERROR("LOAD_BADMACHO file_start / file_size wrap "
"[0x%llx:0x%llx] -> [0x%llx:0x%llx]\n",
file_offset,
file_offset + file_size,
(uint64_t) file_start,
(uint64_t) file_end);
return LOAD_BADMACHO;
}
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 (file_offset - file_start > effective_page_mask ||
file_end - file_offset - file_size > effective_page_mask) {
DEBUG4K_ERROR("LOAD_BADMACHO file_start / file_size wrap "
"[0x%llx:0x%llx] -> [0x%llx:0x%llx]\n",
file_offset,
file_offset + file_size,
(uint64_t) file_start,
(uint64_t) file_end);
return LOAD_BADMACHO;
}
}
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 (scp->flags & SG_READ_ONLY) {
/*
* Record the VM start/end of a segment which should
* be RO after fixups. Only __DATA_CONST should
* have this flag.
*/
if (result->ro_vm_start != MACH_VM_MIN_ADDRESS ||
result->ro_vm_end != MACH_VM_MIN_ADDRESS) {
DEBUG4K_ERROR("LOAD_BADMACHO segment flags [%x] "
"multiple segments with SG_READ_ONLY flag\n",
scp->flags);
return LOAD_BADMACHO;
}
result->ro_vm_start = vm_start;
result->ro_vm_end = vm_end;
}
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) {
DEBUG4K_ERROR("LOAD_NOSPACE start 0x%llx end 0x%llx ret 0x%x\n", (uint64_t)vm_start, (uint64_t)vm_end, 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) {
void *tmp = kalloc_data(delta_size, Z_WAITOK | Z_ZERO);
int rc;
if (tmp == NULL) {
DEBUG4K_ERROR("LOAD_RESOURCE delta_size 0x%llx ret 0x%x\n", delta_size, ret);
return LOAD_RESOURCE;
}
rc = copyout(tmp, map_addr + scp->filesize, delta_size);
kfree_data(tmp, delta_size);
if (rc) {
DEBUG4K_ERROR("LOAD_FAILURE copyout 0x%llx 0x%llx\n", map_addr + scp->filesize, delta_size);
return LOAD_FAILURE;
}
}
#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) {
vm_map_offset_t tmp_start;
vm_map_offset_t tmp_end;
if (os_add_overflow(vm_start, file_end - file_start, &tmp_start)) {
DEBUG4K_ERROR("LOAD_NOSPACE tmp_start: 0x%llx + 0x%llx\n", (uint64_t)vm_start, (uint64_t)(file_end - file_start));
return LOAD_NOSPACE;
}
if (os_add_overflow(tmp_start, delta_size, &tmp_end)) {
DEBUG4K_ERROR("LOAD_NOSPACE tmp_end: 0x%llx + 0x%llx\n", (uint64_t)tmp_start, (uint64_t)delta_size);
return LOAD_NOSPACE;
}
if (verbose) {
MACHO_PRINTF(("++++++ load_segment: "
"delta mapping vm [0x%llx:0x%llx]\n",
(uint64_t) tmp_start,
(uint64_t) tmp_end));
}
kr = map_segment(map,
tmp_start,
tmp_end,
MEMORY_OBJECT_CONTROL_NULL,
0,
delta_size,
scp->initprot,
scp->maxprot,
result);
if (kr != KERN_SUCCESS) {
DEBUG4K_ERROR("LOAD_NOSPACE 0x%llx 0x%llx kr 0x%x\n", (unsigned long long)tmp_start, (uint64_t)delta_size, kr);
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) {
DEBUG4K_ERROR("unprotect 0x%llx 0x%llx ret %d \n", (uint64_t)vm_start, (uint64_t)vm_end, ret);
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;
}
}
}
if (ret != LOAD_SUCCESS && verbose) {
DEBUG4K_ERROR("ret %d\n", ret);
}
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,
struct image_params *imgp __unused,
load_result_t *result
)
{
uint32_t platform = 0;
uint32_t sdk;
uint32_t min_sdk;
if (vmc->cmdsize < sizeof(*vmc)) {
return LOAD_BADMACHO;
}
if (*found_version_cmd == TRUE) {
return LOAD_BADMACHO;
}
*found_version_cmd = TRUE;
sdk = vmc->sdk;
min_sdk = vmc->version;
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__
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;
min_sdk = (uint32_t)-1;
__builtin_unreachable();
}
result->ip_platform = platform;
result->lr_min_sdk = min_sdk;
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;
}
/*
* 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;
}
result->custom_stack = TRUE;
} else {
result->user_stack_alloc_size = MAXSSIZ;
}
/* use default location for stack */
ret = thread_userstackdefault(&addr, result->is_64bit_addr);
if (ret != KERN_SUCCESS) {
return LOAD_FAILURE;
}
/* The stack slides down from the default location */
result->user_stack = (user_addr_t)mach_vm_trunc_page((user_addr_t)addr - 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
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;
}
result->user_stack_alloc_size = MAXSSIZ;
/* use default location for stack */
ret = thread_userstackdefault(&addr, result->is_64bit_addr);
if (ret != KERN_SUCCESS) {
return LOAD_FAILURE;
}
/* The stack slides down from the default location */
result->user_stack = (user_addr_t)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;
}
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,
boolean_t is_x86_64_compat_binary,
load_result_t *result
)
{
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) {
return LOAD_FAILURE;
}
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),
&addr, &customstack, is_x86_64_compat_binary, result);
if (ret != LOAD_SUCCESS) {
return ret;
}
/* LC_UNIXTHREAD optionally specifies stack size and location */
if (customstack) {
result->custom_stack = TRUE;
} else {
result->user_stack_alloc_size = MAXSSIZ;
}
/* The stack slides down from the default location */
result->user_stack = (user_addr_t)mach_vm_trunc_page((user_addr_t)addr - slide);
{
ret = load_threadentry(thread,
(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 = (user_addr_t)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),
result);
if (ret != LOAD_SUCCESS) {
return ret;
}
}
result->unixproc = TRUE;
result->thread_count++;
return LOAD_SUCCESS;
}
static
load_return_t
load_threadstate(
thread_t thread,
uint32_t *ts,
uint32_t total_size,
load_result_t *result
)
{
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 = (uint32_t *)kalloc_data(local_ts_size, Z_WAITOK);
if (local_ts == NULL) {
return LOAD_FAILURE;
}
memcpy(local_ts, ts, local_ts_size);
ts = local_ts;
}
/*
* 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) {
if (total_size < 2 * sizeof(uint32_t)) {
return LOAD_BADMACHO;
}
flavor = *ts++;
size = *ts++;
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 *) */
}
result->threadstate = local_ts;
result->threadstate_sz = local_ts_size;
return LOAD_SUCCESS;
bad:
if (local_ts) {
kfree_data(local_ts, local_ts_size);
}
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,
__unused boolean_t is_x86_64_compat_binary,
load_result_t *result
)
{
kern_return_t ret;
uint32_t size;
int flavor;
uint32_t stack_size;
if (total_size == 0) {
return LOAD_BADMACHO;
}
while (total_size > 0) {
if (total_size < 2 * sizeof(uint32_t)) {
return LOAD_BADMACHO;
}
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;
}
total_size -= stack_size;
/*
* Third argument is a kernel space pointer; it gets cast
* 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, result->is_64bit_data);
if (ret != KERN_SUCCESS) {
return LOAD_FAILURE;
}
}
ts += size; /* ts is a (uint32_t *) */
}
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
)
{
kern_return_t ret;
uint32_t size;
int flavor;
uint32_t entry_size;
/*
* Set the thread state.
*/
*entry_point = MACH_VM_MIN_ADDRESS;
while (total_size > 0) {
if (total_size < 2 * sizeof(uint32_t)) {
return LOAD_BADMACHO;
}
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;
}
total_size -= entry_size;
/*
* Third argument is a kernel space pointer; it gets cast
* to the appropriate type in thread_entrypoint() based on
* the value of flavor.
*/
ret = thread_entrypoint(thread, flavor, (thread_state_t)ts, size, entry_point);
if (ret != KERN_SUCCESS) {
return LOAD_FAILURE;
}
ts += size; /* ts is a (uint32_t *) */
}
return LOAD_SUCCESS;
}
struct macho_data {
struct nameidata __nid;
union macho_vnode_header {
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;
extern char dyld_suffix[];
extern int use_dyld_suffix;
typedef struct _dyld_suffix_map_entry {
const char *suffix;
const char *path;
} dyld_suffix_map_entry_t;
static const dyld_suffix_map_entry_t _dyld_suffix_map[] = {
[0] = {
.suffix = "",
.path = DEFAULT_DYLD_PATH,
}, {
.suffix = "release",
.path = DEFAULT_DYLD_PATH,
}, {
.suffix = "bringup",
.path = "/usr/appleinternal/lib/dyld.bringup",
},
};
#endif
static load_return_t
load_dylinker(
struct dylinker_command *lcp,
cpu_type_t cputype,
vm_map_t map,
thread_t thread,
int depth,
int64_t slide,
load_result_t *result,
struct image_params *imgp
)
{
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;
} *dyld_data;
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)
/*
* 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;
}
}
} else if (use_dyld_suffix) {
size_t i = 0;
#define countof(x) (sizeof(x) / sizeof(x[0]))
for (i = 0; i < countof(_dyld_suffix_map); i++) {
const dyld_suffix_map_entry_t *entry = &_dyld_suffix_map[i];
if (strcmp(entry->suffix, dyld_suffix) == 0) {
name = entry->path;
break;
}
}
}
#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 */
dyld_data = kalloc_type(typeof(*dyld_data), Z_WAITOK);
header = &dyld_data->__header;
myresult = &dyld_data->__myresult;
macho_data = &dyld_data->__macho_data;
{
cputype = (cputype & CPU_ARCH_MASK) | (cpu_type() & ~CPU_ARCH_MASK);
}
ret = get_macho_vnode(name, cputype, header,
&file_offset, &macho_size, macho_data, &vp, imgp);
if (ret) {
goto novp_out;
}
*myresult = load_result_null;
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, 0, myresult, result, imgp);
if (ret == LOAD_SUCCESS) {
if (result->threadstate) {
/* don't use the app's threadstate if we have a dyld */
kfree_data(result->threadstate, result->threadstate_sz);
}
result->threadstate = myresult->threadstate;
result->threadstate_sz = myresult->threadstate_sz;
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_NO_UNTRUSTED_HELPERS;
}
#if CONFIG_ROSETTA
if (imgp->ip_flags & IMGPF_ROSETTA) {
extern const struct fileops vnops;
// Save the file descriptor and mach header address for dyld. These will
// be passed on the stack for the Rosetta runtime's use.
struct fileproc *fp;
int dyld_fd;
proc_t p = vfs_context_proc(imgp->ip_vfs_context);
int error = falloc(p, &fp, &dyld_fd, imgp->ip_vfs_context);
if (error == 0) {
error = VNOP_OPEN(vp, FREAD, imgp->ip_vfs_context);
if (error == 0) {
fp->fp_glob->fg_flag = FREAD;
fp->fp_glob->fg_ops = &vnops;
fp_set_data(fp, vp);
proc_fdlock(p);
procfdtbl_releasefd(p, dyld_fd, NULL);
fp_drop(p, dyld_fd, fp, 1);
proc_fdunlock(p);
vnode_ref(vp);
result->dynlinker_fd = dyld_fd;
result->dynlinker_fp = fp;
result->dynlinker_mach_header = myresult->mach_header;
result->dynlinker_max_vm_addr = myresult->max_vm_addr;
result->dynlinker_ro_vm_start = myresult->ro_vm_start;
result->dynlinker_ro_vm_end = myresult->ro_vm_end;
} else {
fp_free(p, dyld_fd, fp);
ret = LOAD_IOERROR;
}
} else {
ret = LOAD_IOERROR;
}
}
#endif
}
struct vnode_attr *va;
va = kalloc_type(struct vnode_attr, Z_WAITOK | Z_ZERO);
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);
kfree_type(struct vnode_attr, va);
novp_out:
kfree_type(typeof(*dyld_data), dyld_data);
return ret;
}
#if CONFIG_ROSETTA
static const char* rosetta_runtime_path = "/usr/libexec/rosetta/runtime";
#if (DEVELOPMENT || DEBUG)
static const char* rosetta_runtime_path_alt_x86 = "/usr/local/libexec/rosetta/runtime_internal";
static const char* rosetta_runtime_path_alt_arm = "/usr/local/libexec/rosetta/runtime_arm_internal";
#endif
static load_return_t
load_rosetta(
vm_map_t map,
thread_t thread,
load_result_t *result,
struct image_params *imgp)
{
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 *rosetta_file_path;
struct {
struct mach_header __header;
load_result_t __myresult;
struct macho_data __macho_data;
} *rosetta_data;
mach_vm_address_t rosetta_load_addr;
mach_vm_size_t rosetta_size;
mach_vm_address_t shared_cache_base = SHARED_REGION_BASE_ARM64;
int64_t slide = 0;
/* Allocate wad-of-data from heap to reduce excessively deep stacks */
rosetta_data = kalloc_type(typeof(*rosetta_data), Z_WAITOK | Z_NOFAIL);
header = &rosetta_data->__header;
myresult = &rosetta_data->__myresult;
macho_data = &rosetta_data->__macho_data;
rosetta_file_path = rosetta_runtime_path;
#if (DEVELOPMENT || DEBUG)
bool use_alt_rosetta = false;
if (imgp->ip_flags & IMGPF_ALT_ROSETTA) {
use_alt_rosetta = true;
} else {
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 && (policy_flags & PROC_UUID_ALT_ROSETTA_POLICY) != 0) {
use_alt_rosetta = true;
}
}
if (use_alt_rosetta) {
if (imgp->ip_origcputype == CPU_TYPE_X86_64) {
rosetta_file_path = rosetta_runtime_path_alt_x86;
} else if (imgp->ip_origcputype == CPU_TYPE_ARM64) {
rosetta_file_path = rosetta_runtime_path_alt_arm;
} else {
ret = LOAD_BADARCH;
goto novp_out;
}
}
#endif
ret = get_macho_vnode(rosetta_file_path, CPU_TYPE_ARM64, header,
&file_offset, &macho_size, macho_data, &vp, imgp);
if (ret) {
goto novp_out;
}
*myresult = load_result_null;
myresult->is_64bit_addr = TRUE;
myresult->is_64bit_data = TRUE;
ret = parse_machfile(vp, NULL, NULL, header, file_offset, macho_size,
2, 0, 0, myresult, NULL, imgp);
if (ret != LOAD_SUCCESS) {
goto out;
}
if (!(imgp->ip_flags & IMGPF_DISABLE_ASLR)) {
slide = random();
slide = (slide % (vm_map_get_max_loader_aslr_slide_pages(map) - 1)) + 1;
slide <<= vm_map_page_shift(map);
}
if (imgp->ip_origcputype == CPU_TYPE_X86_64) {
shared_cache_base = SHARED_REGION_BASE_X86_64;
}
rosetta_size = round_page(myresult->max_vm_addr - myresult->min_vm_addr);
rosetta_load_addr = shared_cache_base - rosetta_size - slide;
*myresult = load_result_null;
myresult->is_64bit_addr = TRUE;
myresult->is_64bit_data = TRUE;
myresult->is_rosetta = TRUE;
ret = parse_machfile(vp, map, thread, header, file_offset, macho_size,
2, rosetta_load_addr, 0, myresult, result, imgp);
if (ret == LOAD_SUCCESS) {
if (result) {
if (result->threadstate) {
/* don't use the app's/dyld's threadstate */
kfree_data(result->threadstate, result->threadstate_sz);
}
assert(myresult->threadstate != NULL);
result->is_rosetta = TRUE;
result->threadstate = myresult->threadstate;
result->threadstate_sz = myresult->threadstate_sz;
result->entry_point = myresult->entry_point;
result->validentry = myresult->validentry;
if (!myresult->platform_binary) {
result->csflags &= ~CS_NO_UNTRUSTED_HELPERS;
}
if ((header->cpusubtype & ~CPU_SUBTYPE_MASK) != CPU_SUBTYPE_ARM64E) {
imgp->ip_flags |= IMGPF_NOJOP;
}
}
}
out:
vnode_put(vp);
novp_out:
kfree_type(typeof(*rosetta_data), rosetta_data);
return ret;
}
#endif
static void
set_signature_error(
struct vnode* vp,
struct image_params * imgp,
const char* fatal_failure_desc,
const size_t fatal_failure_desc_len)
{
char *vn_path = NULL;
vm_size_t vn_pathlen = MAXPATHLEN;
char const *path = NULL;
vn_path = zalloc(ZV_NAMEI);
if (vn_getpath(vp, vn_path, (int*)&vn_pathlen) == 0) {
path = vn_path;
} else {
path = "(get vnode path failed)";
}
os_reason_t reason = os_reason_create(OS_REASON_CODESIGNING,
CODESIGNING_EXIT_REASON_TASKGATED_INVALID_SIG);
if (reason == OS_REASON_NULL) {
printf("load_code_signature: %s: failure to allocate exit reason for validation failure: %s\n",
path, fatal_failure_desc);
goto out;
}
imgp->ip_cs_error = reason;
reason->osr_flags = (OS_REASON_FLAG_GENERATE_CRASH_REPORT |
OS_REASON_FLAG_CONSISTENT_FAILURE);
mach_vm_address_t data_addr = 0;
int reason_error = 0;
int kcdata_error = 0;
if ((reason_error = os_reason_alloc_buffer_noblock(reason, kcdata_estimate_required_buffer_size
(1, (uint32_t)fatal_failure_desc_len))) == 0 &&
(kcdata_error = kcdata_get_memory_addr(&reason->osr_kcd_descriptor,
EXIT_REASON_USER_DESC, (uint32_t)fatal_failure_desc_len,
&data_addr)) == KERN_SUCCESS) {
kern_return_t mc_error = kcdata_memcpy(&reason->osr_kcd_descriptor, (mach_vm_address_t)data_addr,
fatal_failure_desc, (uint32_t)fatal_failure_desc_len);
if (mc_error != KERN_SUCCESS) {
printf("load_code_signature: %s: failed to copy reason string "
"(kcdata_memcpy error: %d, length: %ld)\n",
path, mc_error, fatal_failure_desc_len);
}
} else {
printf("load_code_signature: %s: failed to allocate space for reason string "
"(os_reason_alloc_buffer error: %d, kcdata error: %d, length: %ld)\n",
path, reason_error, kcdata_error, fatal_failure_desc_len);
}
out:
if (vn_path) {
zfree(ZV_NAMEI, vn_path);
}
}
static load_return_t
load_code_signature(
struct linkedit_data_command *lcp,
struct vnode *vp,
off_t macho_offset,
off_t macho_size,
cpu_type_t cputype,
cpu_subtype_t cpusubtype,
load_result_t *result,
struct image_params *imgp)
{
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;
boolean_t anyCPU;
addr = 0;
blob = NULL;
cpusubtype &= ~CPU_SUBTYPE_MASK;
blob = ubc_cs_blob_get(vp, cputype, cpusubtype, macho_offset);
if (blob != NULL) {
/* we already have a blob for this vnode and cpu(sub)type */
anyCPU = blob->csb_cpu_type == -1;
if ((blob->csb_cpu_type != cputype &&
blob->csb_cpu_subtype != cpusubtype && !anyCPU) ||
(blob->csb_base_offset != macho_offset) ||
((blob->csb_flags & CS_VALID) == 0)) {
/* the blob has changed for this vnode: fail ! */
ret = LOAD_BADMACHO;
const char* fatal_failure_desc = "embedded signature doesn't match attached signature";
const size_t fatal_failure_desc_len = strlen(fatal_failure_desc) + 1;
printf("load_code_signature: %s\n", fatal_failure_desc);
set_signature_error(vp, imgp, fatal_failure_desc, fatal_failure_desc_len);
goto out;
}
/* It matches the blob we want here, let's verify the version */
if (!anyCPU && 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, result->ip_platform);
if (error == 0) {
/* Revalidation succeeded, we're good! */
/* If we were revaliding a CS blob with any CPU arch we adjust it */
if (anyCPU) {
vnode_lock_spin(vp);
struct cs_cpu_info cpu_info = {
.csb_cpu_type = cputype,
.csb_cpu_subtype = cpusubtype
};
zalloc_ro_update_field(ZONE_ID_CS_BLOB, blob, csb_cpu_info, &cpu_info);
vnode_unlock(vp);
}
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;
}
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_size = lcp->datasize;
kr = ubc_cs_blob_allocate(&addr, &blob_size);
if (kr != KERN_SUCCESS) {
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());
if (error || resid != 0) {
ret = LOAD_IOERROR;
goto out;
}
if (ubc_cs_blob_add(vp,
result->ip_platform,
cputype,
cpusubtype,
macho_offset,
&addr,
lcp->datasize,
imgp,
0,
&blob)) {
if (addr) {
ubc_cs_blob_deallocate(addr, blob_size);
addr = 0;
}
ret = LOAD_FAILURE;
goto out;
} else {
/* ubc_cs_blob_add() has consumed "addr" */
addr = 0;
}
#if CHECK_CS_VALIDATION_BITMAP
ubc_cs_validation_bitmap_allocate( vp );
#endif
ret = LOAD_SUCCESS;
out:
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);
addr = 0;
}
return ret;
}
#if CONFIG_CODE_DECRYPTION
static load_return_t
set_code_unprotect(
struct encryption_info_command *eip,
caddr_t addr,
vm_map_t map,
int64_t slide,
struct vnode *vp,
off_t macho_offset,
cpu_type_t cputype,
cpu_subtype_t cpusubtype)
{
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 (map == VM_MAP_NULL) {
return LOAD_SUCCESS;
}
if (NULL == text_crypter_create) {
return LOAD_FAILURE;
}
vpath = zalloc(ZV_NAMEI);
len = MAXPATHLEN;
error = vn_getpath(vp, vpath, &len);
if (error) {
zfree(ZV_NAMEI, vpath);
return LOAD_FAILURE;
}
if (eip->cryptsize == 0) {
printf("%s:%d '%s': cryptoff 0x%llx cryptsize 0x%llx cryptid 0x%x ignored\n", __FUNCTION__, __LINE__, vpath, (uint64_t)eip->cryptoff, (uint64_t)eip->cryptsize, eip->cryptid);
zfree(ZV_NAMEI, vpath);
return LOAD_SUCCESS;
}
/* set up decrypter first */
crypt_file_data_t crypt_data = {
.filename = vpath,
.cputype = cputype,
.cpusubtype = cpusubtype,
.origin = CRYPT_ORIGIN_APP_LAUNCH,
};
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",
proc_getpid(p), p->p_comm, map, __FUNCTION__, vpath, kr);
}
#endif /* VM_MAP_DEBUG_APPLE_PROTECT */
zfree(ZV_NAMEI, vpath);
if (kr) {
printf("set_code_unprotect: unable to create decrypter %s, kr=%d\n",
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... */
struct mach_header *header = (struct mach_header *)addr;
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);
}
offset = mach_header_sz;
uint32_t ncmds = header->ncmds;
while (ncmds--) {
/*
* Get a pointer to the command.
*/
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 = (vm_map_offset_t)(seg64->vmaddr + eip->cryptoff - seg64->fileoff + slide);
map_size = eip->cryptsize;
crypto_backing_offset = macho_offset + eip->cryptoff;
goto remap_now;
}
break;
case LC_SEGMENT:
seg32 = (struct segment_command *)lcp;
if ((seg32->fileoff <= eip->cryptoff) &&
(seg32->fileoff + seg32->filesize >=
eip->cryptoff + eip->cryptsize)) {
map_offset = (vm_map_offset_t)(seg32->vmaddr + eip->cryptoff - seg32->fileoff + slide);
map_size = eip->cryptsize;
crypto_backing_offset = macho_offset + eip->cryptoff;
goto remap_now;
}
break;
}
}
/* if we get here, did not find anything */
return LOAD_BADMACHO;
remap_now:
/* now remap using the decrypter */
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,
CRYPTID_APP_ENCRYPTION);
if (kr) {
printf("set_code_unprotect(): mapping failed with %x\n", kr);
return LOAD_PROTECT;
}
return LOAD_SUCCESS;
}
#endif
/*
* This routine exists to support the load_dylinker().
*
* This routine has its own, separate, understanding of the FAT file format,
* which is terrifically unfortunate.
*/
static
load_return_t
get_macho_vnode(
const char *path,
cpu_type_t cputype,
struct mach_header *mach_header,
off_t *file_offset,
off_t *macho_size,
struct macho_data *data,
struct vnode **vpp,
struct image_params *imgp
)
{
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;
/*
* Capture the kernel credential for use in the actual read of the
* file, since the user doing the execution may have execute rights
* but not read rights, but to exec something, we have to either map
* or read it into the new process address space, which requires
* read rights. This is to deal with lack of common credential
* serialization code which would treat NOCRED as "serialize 'root'".
*/
kerncred = vfs_context_ucred(vfs_context_kernel());
/* init the namei data to point the file user's program name */
NDINIT(ndp, LOOKUP, OP_OPEN, FOLLOW | LOCKLEAF, UIO_SYSSPACE, CAST_USER_ADDR_T(path), ctx);
if ((error = namei(ndp)) != 0) {
if (error == ENOENT) {
error = LOAD_ENOENT;
} else {
error = LOAD_FAILURE;
}
return error;
}
nameidone(ndp);
vp = ndp->ni_vp;
/* check for regular file */
if (vp->v_type != VREG) {
error = LOAD_PROTECT;
goto bad1;
}
/* get size */
if ((error = vnode_size(vp, &fsize, ctx)) != 0) {
error = LOAD_FAILURE;
goto bad1;
}
/* Check mount point */
if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
error = LOAD_PROTECT;
goto bad1;
}
/* check access */
if ((error = vnode_authorize(vp, NULL, KAUTH_VNODE_EXECUTE | KAUTH_VNODE_READ_DATA, ctx)) != 0) {
error = LOAD_PROTECT;
goto bad1;
}
/* try to open it */
if ((error = VNOP_OPEN(vp, FREAD, ctx)) != 0) {
error = LOAD_PROTECT;
goto bad1;
}
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 (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), fsize);
if (error != LOAD_SUCCESS) {
goto bad2;
}
/* Look up our architecture in the fat file. */
error = fatfile_getbestarch_for_cputype(cputype, CPU_SUBTYPE_ANY,
(vm_offset_t)(&header->fat_header), sizeof(*header), imgp, &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,
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) {
error = LOAD_BADMACHO;
goto bad2;
}
*file_offset = fat_arch.offset;
*macho_size = fat_arch.size;
} else {
/*
* Force get_macho_vnode() to fail if the architecture bits
* do not match the expected architecture bits. This in
* turn causes load_dylinker() to fail for the same reason,
* so it ensures the dynamic linker and the binary are in
* lock-step. This is potentially bad, if we ever add to
* the CPU_ARCH_* bits any bits that are desirable but not
* required, since the dynamic linker might work, but we will
* refuse to load it because of this check.
*/
if ((cpu_type_t)header->mach_header.cputype != cputype) {
error = LOAD_BADARCH;
goto bad2;
}
*file_offset = 0;
*macho_size = fsize;
}
*mach_header = header->mach_header;
*vpp = vp;
ubc_setsize(vp, fsize);
return error;
bad2:
(void) VNOP_CLOSE(vp, FREAD, ctx);
bad1:
vnode_put(vp);
return error;
}