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gerrit-public.fairphone.software / platform / art / bc5669ee83f45d74e46a6377ad9b2b57f64c2bec / . / runtime / dex_file_verifier.cc
blob: 1d243490ab2df5e28bec6542e7d3d9a9aef5a528 [file] [log] [blame]
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "dex_file_verifier.h"
#include <inttypes.h>
#include <zlib.h>
#include <memory>
#include "base/stringprintf.h"
#include "dex_file-inl.h"
#include "experimental_flags.h"
#include "leb128.h"
#include "runtime.h"
#include "safe_map.h"
#include "utf-inl.h"
#include "utils.h"
namespace art {
static uint32_t MapTypeToBitMask(uint32_t map_type) {
switch (map_type) {
case DexFile::kDexTypeHeaderItem: return 1 << 0;
case DexFile::kDexTypeStringIdItem: return 1 << 1;
case DexFile::kDexTypeTypeIdItem: return 1 << 2;
case DexFile::kDexTypeProtoIdItem: return 1 << 3;
case DexFile::kDexTypeFieldIdItem: return 1 << 4;
case DexFile::kDexTypeMethodIdItem: return 1 << 5;
case DexFile::kDexTypeClassDefItem: return 1 << 6;
case DexFile::kDexTypeMapList: return 1 << 7;
case DexFile::kDexTypeTypeList: return 1 << 8;
case DexFile::kDexTypeAnnotationSetRefList: return 1 << 9;
case DexFile::kDexTypeAnnotationSetItem: return 1 << 10;
case DexFile::kDexTypeClassDataItem: return 1 << 11;
case DexFile::kDexTypeCodeItem: return 1 << 12;
case DexFile::kDexTypeStringDataItem: return 1 << 13;
case DexFile::kDexTypeDebugInfoItem: return 1 << 14;
case DexFile::kDexTypeAnnotationItem: return 1 << 15;
case DexFile::kDexTypeEncodedArrayItem: return 1 << 16;
case DexFile::kDexTypeAnnotationsDirectoryItem: return 1 << 17;
}
return 0;
}
static bool IsDataSectionType(uint32_t map_type) {
switch (map_type) {
case DexFile::kDexTypeHeaderItem:
case DexFile::kDexTypeStringIdItem:
case DexFile::kDexTypeTypeIdItem:
case DexFile::kDexTypeProtoIdItem:
case DexFile::kDexTypeFieldIdItem:
case DexFile::kDexTypeMethodIdItem:
case DexFile::kDexTypeClassDefItem:
return false;
}
return true;
}
const char* DexFileVerifier::CheckLoadStringByIdx(uint32_t idx, const char* error_string) {
if (UNLIKELY(!CheckIndex(idx, dex_file_->NumStringIds(), error_string))) {
return nullptr;
}
return dex_file_->StringDataByIdx(idx);
}
const char* DexFileVerifier::CheckLoadStringByTypeIdx(uint32_t type_idx, const char* error_string) {
if (UNLIKELY(!CheckIndex(type_idx, dex_file_->NumTypeIds(), error_string))) {
return nullptr;
}
const DexFile::TypeId& type_id = dex_file_->GetTypeId(type_idx);
uint32_t idx = type_id.descriptor_idx_;
return CheckLoadStringByIdx(idx, error_string);
}
const DexFile::FieldId* DexFileVerifier::CheckLoadFieldId(uint32_t idx, const char* error_string) {
if (UNLIKELY(!CheckIndex(idx, dex_file_->NumFieldIds(), error_string))) {
return nullptr;
}
return &dex_file_->GetFieldId(idx);
}
const DexFile::MethodId* DexFileVerifier::CheckLoadMethodId(uint32_t idx, const char* err_string) {
if (UNLIKELY(!CheckIndex(idx, dex_file_->NumMethodIds(), err_string))) {
return nullptr;
}
return &dex_file_->GetMethodId(idx);
}
// Helper macro to load string and return false on error.
#define LOAD_STRING(var, idx, error) \
const char* (var) = CheckLoadStringByIdx(idx, error); \
if (UNLIKELY((var) == nullptr)) { \
return false; \
}
// Helper macro to load string by type idx and return false on error.
#define LOAD_STRING_BY_TYPE(var, type_idx, error) \
const char* (var) = CheckLoadStringByTypeIdx(type_idx, error); \
if (UNLIKELY((var) == nullptr)) { \
return false; \
}
// Helper macro to load method id. Return last parameter on error.
#define LOAD_METHOD(var, idx, error_string, error_stmt) \
const DexFile::MethodId* (var) = CheckLoadMethodId(idx, error_string); \
if (UNLIKELY((var) == nullptr)) { \
error_stmt; \
}
// Helper macro to load method id. Return last parameter on error.
#define LOAD_FIELD(var, idx, fmt, error_stmt) \
const DexFile::FieldId* (var) = CheckLoadFieldId(idx, fmt); \
if (UNLIKELY((var) == nullptr)) { \
error_stmt; \
}
bool DexFileVerifier::Verify(const DexFile* dex_file, const uint8_t* begin, size_t size,
const char* location, std::string* error_msg) {
std::unique_ptr<DexFileVerifier> verifier(new DexFileVerifier(dex_file, begin, size, location));
if (!verifier->Verify()) {
*error_msg = verifier->FailureReason();
return false;
}
return true;
}
bool DexFileVerifier::CheckShortyDescriptorMatch(char shorty_char, const char* descriptor,
bool is_return_type) {
switch (shorty_char) {
case 'V':
if (UNLIKELY(!is_return_type)) {
ErrorStringPrintf("Invalid use of void");
return false;
}
FALLTHROUGH_INTENDED;
case 'B':
case 'C':
case 'D':
case 'F':
case 'I':
case 'J':
case 'S':
case 'Z':
if (UNLIKELY((descriptor[0] != shorty_char) || (descriptor[1] != '\0'))) {
ErrorStringPrintf("Shorty vs. primitive type mismatch: '%c', '%s'",
shorty_char, descriptor);
return false;
}
break;
case 'L':
if (UNLIKELY((descriptor[0] != 'L') && (descriptor[0] != '['))) {
ErrorStringPrintf("Shorty vs. type mismatch: '%c', '%s'", shorty_char, descriptor);
return false;
}
break;
default:
ErrorStringPrintf("Bad shorty character: '%c'", shorty_char);
return false;
}
return true;
}
bool DexFileVerifier::CheckListSize(const void* start, size_t count, size_t elem_size,
const char* label) {
// Check that size is not 0.
CHECK_NE(elem_size, 0U);
const uint8_t* range_start = reinterpret_cast<const uint8_t*>(start);
const uint8_t* file_start = reinterpret_cast<const uint8_t*>(begin_);
// Check for overflow.
uintptr_t max = 0 - 1;
size_t available_bytes_till_end_of_mem = max - reinterpret_cast<uintptr_t>(start);
size_t max_count = available_bytes_till_end_of_mem / elem_size;
if (max_count < count) {
ErrorStringPrintf("Overflow in range for %s: %zx for %zu@%zu", label,
static_cast<size_t>(range_start - file_start),
count, elem_size);
return false;
}
const uint8_t* range_end = range_start + count * elem_size;
const uint8_t* file_end = file_start + size_;
if (UNLIKELY((range_start < file_start) || (range_end > file_end))) {
// Note: these two tests are enough as we make sure above that there's no overflow.
ErrorStringPrintf("Bad range for %s: %zx to %zx", label,
static_cast<size_t>(range_start - file_start),
static_cast<size_t>(range_end - file_start));
return false;
}
return true;
}
bool DexFileVerifier::CheckList(size_t element_size, const char* label, const uint8_t* *ptr) {
// Check that the list is available. The first 4B are the count.
if (!CheckListSize(*ptr, 1, 4U, label)) {
return false;
}
uint32_t count = *reinterpret_cast<const uint32_t*>(*ptr);
if (count > 0) {
if (!CheckListSize(*ptr + 4, count, element_size, label)) {
return false;
}
}
*ptr += 4 + count * element_size;
return true;
}
bool DexFileVerifier::CheckIndex(uint32_t field, uint32_t limit, const char* label) {
if (UNLIKELY(field >= limit)) {
ErrorStringPrintf("Bad index for %s: %x >= %x", label, field, limit);
return false;
}
return true;
}
bool DexFileVerifier::CheckValidOffsetAndSize(uint32_t offset,
uint32_t size,
size_t alignment,
const char* label) {
if (size == 0) {
if (offset != 0) {
ErrorStringPrintf("Offset(%d) should be zero when size is zero for %s.", offset, label);
return false;
}
}
if (size_ <= offset) {
ErrorStringPrintf("Offset(%d) should be within file size(%zu) for %s.", offset, size_, label);
return false;
}
if (alignment != 0 && !IsAlignedParam(offset, alignment)) {
ErrorStringPrintf("Offset(%d) should be aligned by %zu for %s.", offset, alignment, label);
return false;
}
return true;
}
bool DexFileVerifier::CheckSizeLimit(uint32_t size, uint32_t limit, const char* label) {
if (size > limit) {
ErrorStringPrintf("Size(%u) should not exceed limit(%u) for %s.", size, limit, label);
return false;
}
return true;
}
bool DexFileVerifier::CheckHeader() {
// Check file size from the header.
uint32_t expected_size = header_->file_size_;
if (size_ != expected_size) {
ErrorStringPrintf("Bad file size (%zd, expected %ud)", size_, expected_size);
return false;
}
// Compute and verify the checksum in the header.
uint32_t adler_checksum = adler32(0L, Z_NULL, 0);
const uint32_t non_sum = sizeof(header_->magic_) + sizeof(header_->checksum_);
const uint8_t* non_sum_ptr = reinterpret_cast<const uint8_t*>(header_) + non_sum;
adler_checksum = adler32(adler_checksum, non_sum_ptr, expected_size - non_sum);
if (adler_checksum != header_->checksum_) {
ErrorStringPrintf("Bad checksum (%08x, expected %08x)", adler_checksum, header_->checksum_);
return false;
}
// Check the contents of the header.
if (header_->endian_tag_ != DexFile::kDexEndianConstant) {
ErrorStringPrintf("Unexpected endian_tag: %x", header_->endian_tag_);
return false;
}
if (header_->header_size_ != sizeof(DexFile::Header)) {
ErrorStringPrintf("Bad header size: %ud", header_->header_size_);
return false;
}
// Check that all offsets are inside the file.
bool result =
CheckValidOffsetAndSize(header_->link_off_,
header_->link_size_,
0 /* unaligned */,
"link") &&
CheckValidOffsetAndSize(header_->map_off_,
header_->map_off_,
4,
"map") &&
CheckValidOffsetAndSize(header_->string_ids_off_,
header_->string_ids_size_,
4,
"string-ids") &&
CheckValidOffsetAndSize(header_->type_ids_off_,
header_->type_ids_size_,
4,
"type-ids") &&
CheckSizeLimit(header_->type_ids_size_, DexFile::kDexNoIndex16, "type-ids") &&
CheckValidOffsetAndSize(header_->proto_ids_off_,
header_->proto_ids_size_,
4,
"proto-ids") &&
CheckSizeLimit(header_->proto_ids_size_, DexFile::kDexNoIndex16, "proto-ids") &&
CheckValidOffsetAndSize(header_->field_ids_off_,
header_->field_ids_size_,
4,
"field-ids") &&
CheckValidOffsetAndSize(header_->method_ids_off_,
header_->method_ids_size_,
4,
"method-ids") &&
CheckValidOffsetAndSize(header_->class_defs_off_,
header_->class_defs_size_,
4,
"class-defs") &&
CheckValidOffsetAndSize(header_->data_off_,
header_->data_size_,
0, // Unaligned, spec doesn't talk about it, even though size
// is supposed to be a multiple of 4.
"data");
return result;
}
bool DexFileVerifier::CheckMap() {
const DexFile::MapList* map = reinterpret_cast<const DexFile::MapList*>(begin_ +
header_->map_off_);
// Check that map list content is available.
if (!CheckListSize(map, 1, sizeof(DexFile::MapList), "maplist content")) {
return false;
}
const DexFile::MapItem* item = map->list_;
uint32_t count = map->size_;
uint32_t last_offset = 0;
uint32_t data_item_count = 0;
uint32_t data_items_left = header_->data_size_;
uint32_t used_bits = 0;
// Sanity check the size of the map list.
if (!CheckListSize(item, count, sizeof(DexFile::MapItem), "map size")) {
return false;
}
// Check the items listed in the map.
for (uint32_t i = 0; i < count; i++) {
if (UNLIKELY(last_offset >= item->offset_ && i != 0)) {
ErrorStringPrintf("Out of order map item: %x then %x", last_offset, item->offset_);
return false;
}
if (UNLIKELY(item->offset_ >= header_->file_size_)) {
ErrorStringPrintf("Map item after end of file: %x, size %x",
item->offset_, header_->file_size_);
return false;
}
if (IsDataSectionType(item->type_)) {
uint32_t icount = item->size_;
if (UNLIKELY(icount > data_items_left)) {
ErrorStringPrintf("Too many items in data section: %ud", data_item_count + icount);
return false;
}
data_items_left -= icount;
data_item_count += icount;
}
uint32_t bit = MapTypeToBitMask(item->type_);
if (UNLIKELY(bit == 0)) {
ErrorStringPrintf("Unknown map section type %x", item->type_);
return false;
}
if (UNLIKELY((used_bits & bit) != 0)) {
ErrorStringPrintf("Duplicate map section of type %x", item->type_);
return false;
}
used_bits |= bit;
last_offset = item->offset_;
item++;
}
// Check for missing sections in the map.
if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeHeaderItem)) == 0)) {
ErrorStringPrintf("Map is missing header entry");
return false;
}
if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeMapList)) == 0)) {
ErrorStringPrintf("Map is missing map_list entry");
return false;
}
if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeStringIdItem)) == 0 &&
((header_->string_ids_off_ != 0) || (header_->string_ids_size_ != 0)))) {
ErrorStringPrintf("Map is missing string_ids entry");
return false;
}
if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeTypeIdItem)) == 0 &&
((header_->type_ids_off_ != 0) || (header_->type_ids_size_ != 0)))) {
ErrorStringPrintf("Map is missing type_ids entry");
return false;
}
if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeProtoIdItem)) == 0 &&
((header_->proto_ids_off_ != 0) || (header_->proto_ids_size_ != 0)))) {
ErrorStringPrintf("Map is missing proto_ids entry");
return false;
}
if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeFieldIdItem)) == 0 &&
((header_->field_ids_off_ != 0) || (header_->field_ids_size_ != 0)))) {
ErrorStringPrintf("Map is missing field_ids entry");
return false;
}
if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeMethodIdItem)) == 0 &&
((header_->method_ids_off_ != 0) || (header_->method_ids_size_ != 0)))) {
ErrorStringPrintf("Map is missing method_ids entry");
return false;
}
if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeClassDefItem)) == 0 &&
((header_->class_defs_off_ != 0) || (header_->class_defs_size_ != 0)))) {
ErrorStringPrintf("Map is missing class_defs entry");
return false;
}
return true;
}
uint32_t DexFileVerifier::ReadUnsignedLittleEndian(uint32_t size) {
uint32_t result = 0;
if (LIKELY(CheckListSize(ptr_, size, sizeof(uint8_t), "encoded_value"))) {
for (uint32_t i = 0; i < size; i++) {
result |= ((uint32_t) *(ptr_++)) << (i * 8);
}
}
return result;
}
bool DexFileVerifier::CheckAndGetHandlerOffsets(const DexFile::CodeItem* code_item,
uint32_t* handler_offsets, uint32_t handlers_size) {
const uint8_t* handlers_base = DexFile::GetCatchHandlerData(*code_item, 0);
for (uint32_t i = 0; i < handlers_size; i++) {
bool catch_all;
size_t offset = ptr_ - handlers_base;
int32_t size = DecodeSignedLeb128(&ptr_);
if (UNLIKELY((size < -65536) || (size > 65536))) {
ErrorStringPrintf("Invalid exception handler size: %d", size);
return false;
}
if (size <= 0) {
catch_all = true;
size = -size;
} else {
catch_all = false;
}
handler_offsets[i] = static_cast<uint32_t>(offset);
while (size-- > 0) {
uint32_t type_idx = DecodeUnsignedLeb128(&ptr_);
if (!CheckIndex(type_idx, header_->type_ids_size_, "handler type_idx")) {
return false;
}
uint32_t addr = DecodeUnsignedLeb128(&ptr_);
if (UNLIKELY(addr >= code_item->insns_size_in_code_units_)) {
ErrorStringPrintf("Invalid handler addr: %x", addr);
return false;
}
}
if (catch_all) {
uint32_t addr = DecodeUnsignedLeb128(&ptr_);
if (UNLIKELY(addr >= code_item->insns_size_in_code_units_)) {
ErrorStringPrintf("Invalid handler catch_all_addr: %x", addr);
return false;
}
}
}
return true;
}
bool DexFileVerifier::CheckClassDataItemField(uint32_t idx,
uint32_t access_flags,
uint32_t class_access_flags,
uint16_t class_type_index,
bool expect_static) {
// Check for overflow.
if (!CheckIndex(idx, header_->field_ids_size_, "class_data_item field_idx")) {
return false;
}
// Check that it's the right class.
uint16_t my_class_index =
(reinterpret_cast<const DexFile::FieldId*>(begin_ + header_->field_ids_off_) + idx)->
class_idx_;
if (class_type_index != my_class_index) {
ErrorStringPrintf("Field's class index unexpected, %" PRIu16 "vs %" PRIu16,
my_class_index,
class_type_index);
return false;
}
// Check that it falls into the right class-data list.
bool is_static = (access_flags & kAccStatic) != 0;
if (UNLIKELY(is_static != expect_static)) {
ErrorStringPrintf("Static/instance field not in expected list");
return false;
}
// Check field access flags.
std::string error_msg;
if (!CheckFieldAccessFlags(idx, access_flags, class_access_flags, &error_msg)) {
ErrorStringPrintf("%s", error_msg.c_str());
return false;
}
return true;
}
bool DexFileVerifier::CheckClassDataItemMethod(uint32_t idx,
uint32_t access_flags,
uint32_t class_access_flags,
uint16_t class_type_index,
uint32_t code_offset,
std::unordered_set<uint32_t>* direct_method_indexes,
bool expect_direct) {
DCHECK(direct_method_indexes != nullptr);
// Check for overflow.
if (!CheckIndex(idx, header_->method_ids_size_, "class_data_item method_idx")) {
return false;
}
// Check that it's the right class.
uint16_t my_class_index =
(reinterpret_cast<const DexFile::MethodId*>(begin_ + header_->method_ids_off_) + idx)->
class_idx_;
if (class_type_index != my_class_index) {
ErrorStringPrintf("Method's class index unexpected, %" PRIu16 "vs %" PRIu16,
my_class_index,
class_type_index);
return false;
}
// Check that it's not defined as both direct and virtual.
if (expect_direct) {
direct_method_indexes->insert(idx);
} else if (direct_method_indexes->find(idx) != direct_method_indexes->end()) {
ErrorStringPrintf("Found virtual method with same index as direct method: %d", idx);
return false;
}
// Check method access flags.
bool has_code = (code_offset != 0);
std::string error_msg;
if (!CheckMethodAccessFlags(idx,
access_flags,
class_access_flags,
has_code,
expect_direct,
&error_msg)) {
ErrorStringPrintf("%s", error_msg.c_str());
return false;
}
return true;
}
bool DexFileVerifier::CheckPadding(size_t offset, uint32_t aligned_offset) {
if (offset < aligned_offset) {
if (!CheckListSize(begin_ + offset, aligned_offset - offset, sizeof(uint8_t), "section")) {
return false;
}
while (offset < aligned_offset) {
if (UNLIKELY(*ptr_ != '\0')) {
ErrorStringPrintf("Non-zero padding %x before section start at %zx", *ptr_, offset);
return false;
}
ptr_++;
offset++;
}
}
return true;
}
bool DexFileVerifier::CheckEncodedValue() {
if (!CheckListSize(ptr_, 1, sizeof(uint8_t), "encoded_value header")) {
return false;
}
uint8_t header_byte = *(ptr_++);
uint32_t value_type = header_byte & DexFile::kDexAnnotationValueTypeMask;
uint32_t value_arg = header_byte >> DexFile::kDexAnnotationValueArgShift;
switch (value_type) {
case DexFile::kDexAnnotationByte:
if (UNLIKELY(value_arg != 0)) {
ErrorStringPrintf("Bad encoded_value byte size %x", value_arg);
return false;
}
ptr_++;
break;
case DexFile::kDexAnnotationShort:
case DexFile::kDexAnnotationChar:
if (UNLIKELY(value_arg > 1)) {
ErrorStringPrintf("Bad encoded_value char/short size %x", value_arg);
return false;
}
ptr_ += value_arg + 1;
break;
case DexFile::kDexAnnotationInt:
case DexFile::kDexAnnotationFloat:
if (UNLIKELY(value_arg > 3)) {
ErrorStringPrintf("Bad encoded_value int/float size %x", value_arg);
return false;
}
ptr_ += value_arg + 1;
break;
case DexFile::kDexAnnotationLong:
case DexFile::kDexAnnotationDouble:
ptr_ += value_arg + 1;
break;
case DexFile::kDexAnnotationString: {
if (UNLIKELY(value_arg > 3)) {
ErrorStringPrintf("Bad encoded_value string size %x", value_arg);
return false;
}
uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
if (!CheckIndex(idx, header_->string_ids_size_, "encoded_value string")) {
return false;
}
break;
}
case DexFile::kDexAnnotationType: {
if (UNLIKELY(value_arg > 3)) {
ErrorStringPrintf("Bad encoded_value type size %x", value_arg);
return false;
}
uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
if (!CheckIndex(idx, header_->type_ids_size_, "encoded_value type")) {
return false;
}
break;
}
case DexFile::kDexAnnotationField:
case DexFile::kDexAnnotationEnum: {
if (UNLIKELY(value_arg > 3)) {
ErrorStringPrintf("Bad encoded_value field/enum size %x", value_arg);
return false;
}
uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
if (!CheckIndex(idx, header_->field_ids_size_, "encoded_value field")) {
return false;
}
break;
}
case DexFile::kDexAnnotationMethod: {
if (UNLIKELY(value_arg > 3)) {
ErrorStringPrintf("Bad encoded_value method size %x", value_arg);
return false;
}
uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
if (!CheckIndex(idx, header_->method_ids_size_, "encoded_value method")) {
return false;
}
break;
}
case DexFile::kDexAnnotationArray:
if (UNLIKELY(value_arg != 0)) {
ErrorStringPrintf("Bad encoded_value array value_arg %x", value_arg);
return false;
}
if (!CheckEncodedArray()) {
return false;
}
break;
case DexFile::kDexAnnotationAnnotation:
if (UNLIKELY(value_arg != 0)) {
ErrorStringPrintf("Bad encoded_value annotation value_arg %x", value_arg);
return false;
}
if (!CheckEncodedAnnotation()) {
return false;
}
break;
case DexFile::kDexAnnotationNull:
if (UNLIKELY(value_arg != 0)) {
ErrorStringPrintf("Bad encoded_value null value_arg %x", value_arg);
return false;
}
break;
case DexFile::kDexAnnotationBoolean:
if (UNLIKELY(value_arg > 1)) {
ErrorStringPrintf("Bad encoded_value boolean size %x", value_arg);
return false;
}
break;
default:
ErrorStringPrintf("Bogus encoded_value value_type %x", value_type);
return false;
}
return true;
}
bool DexFileVerifier::CheckEncodedArray() {
uint32_t size = DecodeUnsignedLeb128(&ptr_);
while (size--) {
if (!CheckEncodedValue()) {
failure_reason_ = StringPrintf("Bad encoded_array value: %s", failure_reason_.c_str());
return false;
}
}
return true;
}
bool DexFileVerifier::CheckEncodedAnnotation() {
uint32_t idx = DecodeUnsignedLeb128(&ptr_);
if (!CheckIndex(idx, header_->type_ids_size_, "encoded_annotation type_idx")) {
return false;
}
uint32_t size = DecodeUnsignedLeb128(&ptr_);
uint32_t last_idx = 0;
for (uint32_t i = 0; i < size; i++) {
idx = DecodeUnsignedLeb128(&ptr_);
if (!CheckIndex(idx, header_->string_ids_size_, "annotation_element name_idx")) {
return false;
}
if (UNLIKELY(last_idx >= idx && i != 0)) {
ErrorStringPrintf("Out-of-order annotation_element name_idx: %x then %x",
last_idx, idx);
return false;
}
if (!CheckEncodedValue()) {
return false;
}
last_idx = idx;
}
return true;
}
bool DexFileVerifier::FindClassFlags(uint32_t index,
bool is_field,
uint16_t* class_type_index,
uint32_t* class_access_flags) {
DCHECK(class_type_index != nullptr);
DCHECK(class_access_flags != nullptr);
// First check if the index is valid.
if (index >= (is_field ? header_->field_ids_size_ : header_->method_ids_size_)) {
return false;
}
// Next get the type index.
if (is_field) {
*class_type_index =
(reinterpret_cast<const DexFile::FieldId*>(begin_ + header_->field_ids_off_) + index)->
class_idx_;
} else {
*class_type_index =
(reinterpret_cast<const DexFile::MethodId*>(begin_ + header_->method_ids_off_) + index)->
class_idx_;
}
// Check if that is valid.
if (*class_type_index >= header_->type_ids_size_) {
return false;
}
// Now search for the class def. This is basically a specialized version of the DexFile code, as
// we should not trust that this is a valid DexFile just yet.
const DexFile::ClassDef* class_def_begin =
reinterpret_cast<const DexFile::ClassDef*>(begin_ + header_->class_defs_off_);
for (size_t i = 0; i < header_->class_defs_size_; ++i) {
const DexFile::ClassDef* class_def = class_def_begin + i;
if (class_def->class_idx_ == *class_type_index) {
*class_access_flags = class_def->access_flags_;
return true;
}
}
// Didn't find the class-def, not defined here...
return false;
}
bool DexFileVerifier::CheckOrderAndGetClassFlags(bool is_field,
const char* type_descr,
uint32_t curr_index,
uint32_t prev_index,
bool* have_class,
uint16_t* class_type_index,
uint32_t* class_access_flags) {
if (curr_index < prev_index) {
ErrorStringPrintf("out-of-order %s indexes %" PRIu32 " and %" PRIu32,
type_descr,
prev_index,
curr_index);
return false;
}
if (!*have_class) {
*have_class = FindClassFlags(curr_index, is_field, class_type_index, class_access_flags);
if (!*have_class) {
// Should have really found one.
ErrorStringPrintf("could not find declaring class for %s index %" PRIu32,
type_descr,
curr_index);
return false;
}
}
return true;
}
template <bool kStatic>
bool DexFileVerifier::CheckIntraClassDataItemFields(ClassDataItemIterator* it,
bool* have_class,
uint16_t* class_type_index,
uint32_t* class_access_flags) {
DCHECK(it != nullptr);
// These calls use the raw access flags to check whether the whole dex field is valid.
uint32_t prev_index = 0;
for (; kStatic ? it->HasNextStaticField() : it->HasNextInstanceField(); it->Next()) {
uint32_t curr_index = it->GetMemberIndex();
if (!CheckOrderAndGetClassFlags(true,
kStatic ? "static field" : "instance field",
curr_index,
prev_index,
have_class,
class_type_index,
class_access_flags)) {
return false;
}
prev_index = curr_index;
if (!CheckClassDataItemField(curr_index,
it->GetRawMemberAccessFlags(),
*class_access_flags,
*class_type_index,
kStatic)) {
return false;
}
}
return true;
}
template <bool kDirect>
bool DexFileVerifier::CheckIntraClassDataItemMethods(
ClassDataItemIterator* it,
std::unordered_set<uint32_t>* direct_method_indexes,
bool* have_class,
uint16_t* class_type_index,
uint32_t* class_access_flags) {
uint32_t prev_index = 0;
for (; kDirect ? it->HasNextDirectMethod() : it->HasNextVirtualMethod(); it->Next()) {
uint32_t curr_index = it->GetMemberIndex();
if (!CheckOrderAndGetClassFlags(false,
kDirect ? "direct method" : "virtual method",
curr_index,
prev_index,
have_class,
class_type_index,
class_access_flags)) {
return false;
}
prev_index = curr_index;
if (!CheckClassDataItemMethod(curr_index,
it->GetRawMemberAccessFlags(),
*class_access_flags,
*class_type_index,
it->GetMethodCodeItemOffset(),
direct_method_indexes,
kDirect)) {
return false;
}
}
return true;
}
bool DexFileVerifier::CheckIntraClassDataItem() {
ClassDataItemIterator it(*dex_file_, ptr_);
std::unordered_set<uint32_t> direct_method_indexes;
// This code is complicated by the fact that we don't directly know which class this belongs to.
// So we need to explicitly search with the first item we find (either field or method), and then,
// as the lookup is expensive, cache the result.
bool have_class = false;
uint16_t class_type_index;
uint32_t class_access_flags;
// Check fields.
if (!CheckIntraClassDataItemFields<true>(&it,
&have_class,
&class_type_index,
&class_access_flags)) {
return false;
}
if (!CheckIntraClassDataItemFields<false>(&it,
&have_class,
&class_type_index,
&class_access_flags)) {
return false;
}
// Check methods.
if (!CheckIntraClassDataItemMethods<true>(&it,
&direct_method_indexes,
&have_class,
&class_type_index,
&class_access_flags)) {
return false;
}
if (!CheckIntraClassDataItemMethods<false>(&it,
&direct_method_indexes,
&have_class,
&class_type_index,
&class_access_flags)) {
return false;
}
ptr_ = it.EndDataPointer();
return true;
}
bool DexFileVerifier::CheckIntraCodeItem() {
const DexFile::CodeItem* code_item = reinterpret_cast<const DexFile::CodeItem*>(ptr_);
if (!CheckListSize(code_item, 1, sizeof(DexFile::CodeItem), "code")) {
return false;
}
if (UNLIKELY(code_item->ins_size_ > code_item->registers_size_)) {
ErrorStringPrintf("ins_size (%ud) > registers_size (%ud)",
code_item->ins_size_, code_item->registers_size_);
return false;
}
if (UNLIKELY((code_item->outs_size_ > 5) &&
(code_item->outs_size_ > code_item->registers_size_))) {
/*
* outs_size can be up to 5, even if registers_size is smaller, since the
* short forms of method invocation allow repetitions of a register multiple
* times within a single parameter list. However, longer parameter lists
* need to be represented in-order in the register file.
*/
ErrorStringPrintf("outs_size (%ud) > registers_size (%ud)",
code_item->outs_size_, code_item->registers_size_);
return false;
}
const uint16_t* insns = code_item->insns_;
uint32_t insns_size = code_item->insns_size_in_code_units_;
if (!CheckListSize(insns, insns_size, sizeof(uint16_t), "insns size")) {
return false;
}
// Grab the end of the insns if there are no try_items.
uint32_t try_items_size = code_item->tries_size_;
if (try_items_size == 0) {
ptr_ = reinterpret_cast<const uint8_t*>(&insns[insns_size]);
return true;
}
// try_items are 4-byte aligned. Verify the spacer is 0.
if (((reinterpret_cast<uintptr_t>(&insns[insns_size]) & 3) != 0) && (insns[insns_size] != 0)) {
ErrorStringPrintf("Non-zero padding: %x", insns[insns_size]);
return false;
}
const DexFile::TryItem* try_items = DexFile::GetTryItems(*code_item, 0);
if (!CheckListSize(try_items, try_items_size, sizeof(DexFile::TryItem), "try_items size")) {
return false;
}
ptr_ = DexFile::GetCatchHandlerData(*code_item, 0);
uint32_t handlers_size = DecodeUnsignedLeb128(&ptr_);
if (UNLIKELY((handlers_size == 0) || (handlers_size >= 65536))) {
ErrorStringPrintf("Invalid handlers_size: %ud", handlers_size);
return false;
}
std::unique_ptr<uint32_t[]> handler_offsets(new uint32_t[handlers_size]);
if (!CheckAndGetHandlerOffsets(code_item, &handler_offsets[0], handlers_size)) {
return false;
}
uint32_t last_addr = 0;
while (try_items_size--) {
if (UNLIKELY(try_items->start_addr_ < last_addr)) {
ErrorStringPrintf("Out-of_order try_item with start_addr: %x", try_items->start_addr_);
return false;
}
if (UNLIKELY(try_items->start_addr_ >= insns_size)) {
ErrorStringPrintf("Invalid try_item start_addr: %x", try_items->start_addr_);
return false;
}
uint32_t i;
for (i = 0; i < handlers_size; i++) {
if (try_items->handler_off_ == handler_offsets[i]) {
break;
}
}
if (UNLIKELY(i == handlers_size)) {
ErrorStringPrintf("Bogus handler offset: %x", try_items->handler_off_);
return false;
}
last_addr = try_items->start_addr_ + try_items->insn_count_;
if (UNLIKELY(last_addr > insns_size)) {
ErrorStringPrintf("Invalid try_item insn_count: %x", try_items->insn_count_);
return false;
}
try_items++;
}
return true;
}
bool DexFileVerifier::CheckIntraStringDataItem() {
uint32_t size = DecodeUnsignedLeb128(&ptr_);
const uint8_t* file_end = begin_ + size_;
for (uint32_t i = 0; i < size; i++) {
CHECK_LT(i, size); // b/15014252 Prevents hitting the impossible case below
if (UNLIKELY(ptr_ >= file_end)) {
ErrorStringPrintf("String data would go beyond end-of-file");
return false;
}
uint8_t byte = *(ptr_++);
// Switch on the high 4 bits.
switch (byte >> 4) {
case 0x00:
// Special case of bit pattern 0xxx.
if (UNLIKELY(byte == 0)) {
CHECK_LT(i, size); // b/15014252 Actually hit this impossible case with clang
ErrorStringPrintf("String data shorter than indicated utf16_size %x", size);
return false;
}
break;
case 0x01:
case 0x02:
case 0x03:
case 0x04:
case 0x05:
case 0x06:
case 0x07:
// No extra checks necessary for bit pattern 0xxx.
break;
case 0x08:
case 0x09:
case 0x0a:
case 0x0b:
case 0x0f:
// Illegal bit patterns 10xx or 1111.
// Note: 1111 is valid for normal UTF-8, but not here.
ErrorStringPrintf("Illegal start byte %x in string data", byte);
return false;
case 0x0c:
case 0x0d: {
// Bit pattern 110x has an additional byte.
uint8_t byte2 = *(ptr_++);
if (UNLIKELY((byte2 & 0xc0) != 0x80)) {
ErrorStringPrintf("Illegal continuation byte %x in string data", byte2);
return false;
}
uint16_t value = ((byte & 0x1f) << 6) | (byte2 & 0x3f);
if (UNLIKELY((value != 0) && (value < 0x80))) {
ErrorStringPrintf("Illegal representation for value %x in string data", value);
return false;
}
break;
}
case 0x0e: {
// Bit pattern 1110 has 2 additional bytes.
uint8_t byte2 = *(ptr_++);
if (UNLIKELY((byte2 & 0xc0) != 0x80)) {
ErrorStringPrintf("Illegal continuation byte %x in string data", byte2);
return false;
}
uint8_t byte3 = *(ptr_++);
if (UNLIKELY((byte3 & 0xc0) != 0x80)) {
ErrorStringPrintf("Illegal continuation byte %x in string data", byte3);
return false;
}
uint16_t value = ((byte & 0x0f) << 12) | ((byte2 & 0x3f) << 6) | (byte3 & 0x3f);
if (UNLIKELY(value < 0x800)) {
ErrorStringPrintf("Illegal representation for value %x in string data", value);
return false;
}
break;
}
}
}
if (UNLIKELY(*(ptr_++) != '\0')) {
ErrorStringPrintf("String longer than indicated size %x", size);
return false;
}
return true;
}
bool DexFileVerifier::CheckIntraDebugInfoItem() {
DecodeUnsignedLeb128(&ptr_);
uint32_t parameters_size = DecodeUnsignedLeb128(&ptr_);
if (UNLIKELY(parameters_size > 65536)) {
ErrorStringPrintf("Invalid parameters_size: %x", parameters_size);
return false;
}
for (uint32_t j = 0; j < parameters_size; j++) {
uint32_t parameter_name = DecodeUnsignedLeb128(&ptr_);
if (parameter_name != 0) {
parameter_name--;
if (!CheckIndex(parameter_name, header_->string_ids_size_, "debug_info_item parameter_name")) {
return false;
}
}
}
while (true) {
uint8_t opcode = *(ptr_++);
switch (opcode) {
case DexFile::DBG_END_SEQUENCE: {
return true;
}
case DexFile::DBG_ADVANCE_PC: {
DecodeUnsignedLeb128(&ptr_);
break;
}
case DexFile::DBG_ADVANCE_LINE: {
DecodeSignedLeb128(&ptr_);
break;
}
case DexFile::DBG_START_LOCAL: {
uint32_t reg_num = DecodeUnsignedLeb128(&ptr_);
if (UNLIKELY(reg_num >= 65536)) {
ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
return false;
}
uint32_t name_idx = DecodeUnsignedLeb128(&ptr_);
if (name_idx != 0) {
name_idx--;
if (!CheckIndex(name_idx, header_->string_ids_size_, "DBG_START_LOCAL name_idx")) {
return false;
}
}
uint32_t type_idx = DecodeUnsignedLeb128(&ptr_);
if (type_idx != 0) {
type_idx--;
if (!CheckIndex(type_idx, header_->type_ids_size_, "DBG_START_LOCAL type_idx")) {
return false;
}
}
break;
}
case DexFile::DBG_END_LOCAL:
case DexFile::DBG_RESTART_LOCAL: {
uint32_t reg_num = DecodeUnsignedLeb128(&ptr_);
if (UNLIKELY(reg_num >= 65536)) {
ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
return false;
}
break;
}
case DexFile::DBG_START_LOCAL_EXTENDED: {
uint32_t reg_num = DecodeUnsignedLeb128(&ptr_);
if (UNLIKELY(reg_num >= 65536)) {
ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
return false;
}
uint32_t name_idx = DecodeUnsignedLeb128(&ptr_);
if (name_idx != 0) {
name_idx--;
if (!CheckIndex(name_idx, header_->string_ids_size_, "DBG_START_LOCAL_EXTENDED name_idx")) {
return false;
}
}
uint32_t type_idx = DecodeUnsignedLeb128(&ptr_);
if (type_idx != 0) {
type_idx--;
if (!CheckIndex(type_idx, header_->type_ids_size_, "DBG_START_LOCAL_EXTENDED type_idx")) {
return false;
}
}
uint32_t sig_idx = DecodeUnsignedLeb128(&ptr_);
if (sig_idx != 0) {
sig_idx--;
if (!CheckIndex(sig_idx, header_->string_ids_size_, "DBG_START_LOCAL_EXTENDED sig_idx")) {
return false;
}
}
break;
}
case DexFile::DBG_SET_FILE: {
uint32_t name_idx = DecodeUnsignedLeb128(&ptr_);
if (name_idx != 0) {
name_idx--;
if (!CheckIndex(name_idx, header_->string_ids_size_, "DBG_SET_FILE name_idx")) {
return false;
}
}
break;
}
}
}
}
bool DexFileVerifier::CheckIntraAnnotationItem() {
if (!CheckListSize(ptr_, 1, sizeof(uint8_t), "annotation visibility")) {
return false;
}
// Check visibility
switch (*(ptr_++)) {
case DexFile::kDexVisibilityBuild:
case DexFile::kDexVisibilityRuntime:
case DexFile::kDexVisibilitySystem:
break;
default:
ErrorStringPrintf("Bad annotation visibility: %x", *ptr_);
return false;
}
if (!CheckEncodedAnnotation()) {
return false;
}
return true;
}
bool DexFileVerifier::CheckIntraAnnotationsDirectoryItem() {
const DexFile::AnnotationsDirectoryItem* item =
reinterpret_cast<const DexFile::AnnotationsDirectoryItem*>(ptr_);
if (!CheckListSize(item, 1, sizeof(DexFile::AnnotationsDirectoryItem), "annotations_directory")) {
return false;
}
// Field annotations follow immediately after the annotations directory.
const DexFile::FieldAnnotationsItem* field_item =
reinterpret_cast<const DexFile::FieldAnnotationsItem*>(item + 1);
uint32_t field_count = item->fields_size_;
if (!CheckListSize(field_item, field_count, sizeof(DexFile::FieldAnnotationsItem), "field_annotations list")) {
return false;
}
uint32_t last_idx = 0;
for (uint32_t i = 0; i < field_count; i++) {
if (UNLIKELY(last_idx >= field_item->field_idx_ && i != 0)) {
ErrorStringPrintf("Out-of-order field_idx for annotation: %x then %x", last_idx, field_item->field_idx_);
return false;
}
last_idx = field_item->field_idx_;
field_item++;
}
// Method annotations follow immediately after field annotations.
const DexFile::MethodAnnotationsItem* method_item =
reinterpret_cast<const DexFile::MethodAnnotationsItem*>(field_item);
uint32_t method_count = item->methods_size_;
if (!CheckListSize(method_item, method_count, sizeof(DexFile::MethodAnnotationsItem), "method_annotations list")) {
return false;
}
last_idx = 0;
for (uint32_t i = 0; i < method_count; i++) {
if (UNLIKELY(last_idx >= method_item->method_idx_ && i != 0)) {
ErrorStringPrintf("Out-of-order method_idx for annotation: %x then %x",
last_idx, method_item->method_idx_);
return false;
}
last_idx = method_item->method_idx_;
method_item++;
}
// Parameter annotations follow immediately after method annotations.
const DexFile::ParameterAnnotationsItem* parameter_item =
reinterpret_cast<const DexFile::ParameterAnnotationsItem*>(method_item);
uint32_t parameter_count = item->parameters_size_;
if (!CheckListSize(parameter_item, parameter_count, sizeof(DexFile::ParameterAnnotationsItem),
"parameter_annotations list")) {
return false;
}
last_idx = 0;
for (uint32_t i = 0; i < parameter_count; i++) {
if (UNLIKELY(last_idx >= parameter_item->method_idx_ && i != 0)) {
ErrorStringPrintf("Out-of-order method_idx for annotation: %x then %x",
last_idx, parameter_item->method_idx_);
return false;
}
last_idx = parameter_item->method_idx_;
parameter_item++;
}
// Return a pointer to the end of the annotations.
ptr_ = reinterpret_cast<const uint8_t*>(parameter_item);
return true;
}
bool DexFileVerifier::CheckIntraSectionIterate(size_t offset, uint32_t section_count,
uint16_t type) {
// Get the right alignment mask for the type of section.
size_t alignment_mask;
switch (type) {
case DexFile::kDexTypeClassDataItem:
case DexFile::kDexTypeStringDataItem:
case DexFile::kDexTypeDebugInfoItem:
case DexFile::kDexTypeAnnotationItem:
case DexFile::kDexTypeEncodedArrayItem:
alignment_mask = sizeof(uint8_t) - 1;
break;
default:
alignment_mask = sizeof(uint32_t) - 1;
break;
}
// Iterate through the items in the section.
for (uint32_t i = 0; i < section_count; i++) {
size_t aligned_offset = (offset + alignment_mask) & ~alignment_mask;
// Check the padding between items.
if (!CheckPadding(offset, aligned_offset)) {
return false;
}
// Check depending on the section type.
switch (type) {
case DexFile::kDexTypeStringIdItem: {
if (!CheckListSize(ptr_, 1, sizeof(DexFile::StringId), "string_ids")) {
return false;
}
ptr_ += sizeof(DexFile::StringId);
break;
}
case DexFile::kDexTypeTypeIdItem: {
if (!CheckListSize(ptr_, 1, sizeof(DexFile::TypeId), "type_ids")) {
return false;
}
ptr_ += sizeof(DexFile::TypeId);
break;
}
case DexFile::kDexTypeProtoIdItem: {
if (!CheckListSize(ptr_, 1, sizeof(DexFile::ProtoId), "proto_ids")) {
return false;
}
ptr_ += sizeof(DexFile::ProtoId);
break;
}
case DexFile::kDexTypeFieldIdItem: {
if (!CheckListSize(ptr_, 1, sizeof(DexFile::FieldId), "field_ids")) {
return false;
}
ptr_ += sizeof(DexFile::FieldId);
break;
}
case DexFile::kDexTypeMethodIdItem: {
if (!CheckListSize(ptr_, 1, sizeof(DexFile::MethodId), "method_ids")) {
return false;
}
ptr_ += sizeof(DexFile::MethodId);
break;
}
case DexFile::kDexTypeClassDefItem: {
if (!CheckListSize(ptr_, 1, sizeof(DexFile::ClassDef), "class_defs")) {
return false;
}
ptr_ += sizeof(DexFile::ClassDef);
break;
}
case DexFile::kDexTypeTypeList: {
if (!CheckList(sizeof(DexFile::TypeItem), "type_list", &ptr_)) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationSetRefList: {
if (!CheckList(sizeof(DexFile::AnnotationSetRefItem), "annotation_set_ref_list", &ptr_)) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationSetItem: {
if (!CheckList(sizeof(uint32_t), "annotation_set_item", &ptr_)) {
return false;
}
break;
}
case DexFile::kDexTypeClassDataItem: {
if (!CheckIntraClassDataItem()) {
return false;
}
break;
}
case DexFile::kDexTypeCodeItem: {
if (!CheckIntraCodeItem()) {
return false;
}
break;
}
case DexFile::kDexTypeStringDataItem: {
if (!CheckIntraStringDataItem()) {
return false;
}
break;
}
case DexFile::kDexTypeDebugInfoItem: {
if (!CheckIntraDebugInfoItem()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationItem: {
if (!CheckIntraAnnotationItem()) {
return false;
}
break;
}
case DexFile::kDexTypeEncodedArrayItem: {
if (!CheckEncodedArray()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationsDirectoryItem: {
if (!CheckIntraAnnotationsDirectoryItem()) {
return false;
}
break;
}
default:
ErrorStringPrintf("Unknown map item type %x", type);
return false;
}
if (IsDataSectionType(type)) {
if (aligned_offset == 0u) {
ErrorStringPrintf("Item %d offset is 0", i);
return false;
}
DCHECK(offset_to_type_map_.Find(aligned_offset) == offset_to_type_map_.end());
offset_to_type_map_.Insert(std::pair<uint32_t, uint16_t>(aligned_offset, type));
}
aligned_offset = ptr_ - begin_;
if (UNLIKELY(aligned_offset > size_)) {
ErrorStringPrintf("Item %d at ends out of bounds", i);
return false;
}
offset = aligned_offset;
}
return true;
}
bool DexFileVerifier::CheckIntraIdSection(size_t offset, uint32_t count, uint16_t type) {
uint32_t expected_offset;
uint32_t expected_size;
// Get the expected offset and size from the header.
switch (type) {
case DexFile::kDexTypeStringIdItem:
expected_offset = header_->string_ids_off_;
expected_size = header_->string_ids_size_;
break;
case DexFile::kDexTypeTypeIdItem:
expected_offset = header_->type_ids_off_;
expected_size = header_->type_ids_size_;
break;
case DexFile::kDexTypeProtoIdItem:
expected_offset = header_->proto_ids_off_;
expected_size = header_->proto_ids_size_;
break;
case DexFile::kDexTypeFieldIdItem:
expected_offset = header_->field_ids_off_;
expected_size = header_->field_ids_size_;
break;
case DexFile::kDexTypeMethodIdItem:
expected_offset = header_->method_ids_off_;
expected_size = header_->method_ids_size_;
break;
case DexFile::kDexTypeClassDefItem:
expected_offset = header_->class_defs_off_;
expected_size = header_->class_defs_size_;
break;
default:
ErrorStringPrintf("Bad type for id section: %x", type);
return false;
}
// Check that the offset and size are what were expected from the header.
if (UNLIKELY(offset != expected_offset)) {
ErrorStringPrintf("Bad offset for section: got %zx, expected %x", offset, expected_offset);
return false;
}
if (UNLIKELY(count != expected_size)) {
ErrorStringPrintf("Bad size for section: got %x, expected %x", count, expected_size);
return false;
}
return CheckIntraSectionIterate(offset, count, type);
}
bool DexFileVerifier::CheckIntraDataSection(size_t offset, uint32_t count, uint16_t type) {
size_t data_start = header_->data_off_;
size_t data_end = data_start + header_->data_size_;
// Sanity check the offset of the section.
if (UNLIKELY((offset < data_start) || (offset > data_end))) {
ErrorStringPrintf("Bad offset for data subsection: %zx", offset);
return false;
}
if (!CheckIntraSectionIterate(offset, count, type)) {
return false;
}
size_t next_offset = ptr_ - begin_;
if (next_offset > data_end) {
ErrorStringPrintf("Out-of-bounds end of data subsection: %zx", next_offset);
return false;
}
return true;
}
bool DexFileVerifier::CheckIntraSection() {
const DexFile::MapList* map = reinterpret_cast<const DexFile::MapList*>(begin_ + header_->map_off_);
const DexFile::MapItem* item = map->list_;
uint32_t count = map->size_;
size_t offset = 0;
ptr_ = begin_;
// Check the items listed in the map.
while (count--) {
uint32_t section_offset = item->offset_;
uint32_t section_count = item->size_;
uint16_t type = item->type_;
// Check for padding and overlap between items.
if (!CheckPadding(offset, section_offset)) {
return false;
} else if (UNLIKELY(offset > section_offset)) {
ErrorStringPrintf("Section overlap or out-of-order map: %zx, %x", offset, section_offset);
return false;
}
// Check each item based on its type.
switch (type) {
case DexFile::kDexTypeHeaderItem:
if (UNLIKELY(section_count != 1)) {
ErrorStringPrintf("Multiple header items");
return false;
}
if (UNLIKELY(section_offset != 0)) {
ErrorStringPrintf("Header at %x, not at start of file", section_offset);
return false;
}
ptr_ = begin_ + header_->header_size_;
offset = header_->header_size_;
break;
case DexFile::kDexTypeStringIdItem:
case DexFile::kDexTypeTypeIdItem:
case DexFile::kDexTypeProtoIdItem:
case DexFile::kDexTypeFieldIdItem:
case DexFile::kDexTypeMethodIdItem:
case DexFile::kDexTypeClassDefItem:
if (!CheckIntraIdSection(section_offset, section_count, type)) {
return false;
}
offset = ptr_ - begin_;
break;
case DexFile::kDexTypeMapList:
if (UNLIKELY(section_count != 1)) {
ErrorStringPrintf("Multiple map list items");
return false;
}
if (UNLIKELY(section_offset != header_->map_off_)) {
ErrorStringPrintf("Map not at header-defined offset: %x, expected %x",
section_offset, header_->map_off_);
return false;
}
ptr_ += sizeof(uint32_t) + (map->size_ * sizeof(DexFile::MapItem));
offset = section_offset + sizeof(uint32_t) + (map->size_ * sizeof(DexFile::MapItem));
break;
case DexFile::kDexTypeTypeList:
case DexFile::kDexTypeAnnotationSetRefList:
case DexFile::kDexTypeAnnotationSetItem:
case DexFile::kDexTypeClassDataItem:
case DexFile::kDexTypeCodeItem:
case DexFile::kDexTypeStringDataItem:
case DexFile::kDexTypeDebugInfoItem:
case DexFile::kDexTypeAnnotationItem:
case DexFile::kDexTypeEncodedArrayItem:
case DexFile::kDexTypeAnnotationsDirectoryItem:
if (!CheckIntraDataSection(section_offset, section_count, type)) {
return false;
}
offset = ptr_ - begin_;
break;
default:
ErrorStringPrintf("Unknown map item type %x", type);
return false;
}
item++;
}
return true;
}
bool DexFileVerifier::CheckOffsetToTypeMap(size_t offset, uint16_t type) {
DCHECK_NE(offset, 0u);
auto it = offset_to_type_map_.Find(offset);
if (UNLIKELY(it == offset_to_type_map_.end())) {
ErrorStringPrintf("No data map entry found @ %zx; expected %x", offset, type);
return false;
}
if (UNLIKELY(it->second != type)) {
ErrorStringPrintf("Unexpected data map entry @ %zx; expected %x, found %x",
offset, type, it->second);
return false;
}
return true;
}
uint16_t DexFileVerifier::FindFirstClassDataDefiner(const uint8_t* ptr, bool* success) {
ClassDataItemIterator it(*dex_file_, ptr);
*success = true;
if (it.HasNextStaticField() || it.HasNextInstanceField()) {
LOAD_FIELD(field, it.GetMemberIndex(), "first_class_data_definer field_id",
*success = false; return DexFile::kDexNoIndex16)
return field->class_idx_;
}
if (it.HasNextDirectMethod() || it.HasNextVirtualMethod()) {
LOAD_METHOD(method, it.GetMemberIndex(), "first_class_data_definer method_id",
*success = false; return DexFile::kDexNoIndex16)
return method->class_idx_;
}
return DexFile::kDexNoIndex16;
}
uint16_t DexFileVerifier::FindFirstAnnotationsDirectoryDefiner(const uint8_t* ptr, bool* success) {
const DexFile::AnnotationsDirectoryItem* item =
reinterpret_cast<const DexFile::AnnotationsDirectoryItem*>(ptr);
*success = true;
if (item->fields_size_ != 0) {
DexFile::FieldAnnotationsItem* field_items = (DexFile::FieldAnnotationsItem*) (item + 1);
LOAD_FIELD(field, field_items[0].field_idx_, "first_annotations_dir_definer field_id",
*success = false; return DexFile::kDexNoIndex16)
return field->class_idx_;
}
if (item->methods_size_ != 0) {
DexFile::MethodAnnotationsItem* method_items = (DexFile::MethodAnnotationsItem*) (item + 1);
LOAD_METHOD(method, method_items[0].method_idx_, "first_annotations_dir_definer method id",
*success = false; return DexFile::kDexNoIndex16)
return method->class_idx_;
}
if (item->parameters_size_ != 0) {
DexFile::ParameterAnnotationsItem* parameter_items = (DexFile::ParameterAnnotationsItem*) (item + 1);
LOAD_METHOD(method, parameter_items[0].method_idx_, "first_annotations_dir_definer method id",
*success = false; return DexFile::kDexNoIndex16)
return method->class_idx_;
}
return DexFile::kDexNoIndex16;
}
bool DexFileVerifier::CheckInterStringIdItem() {
const DexFile::StringId* item = reinterpret_cast<const DexFile::StringId*>(ptr_);
// Check the map to make sure it has the right offset->type.
if (!CheckOffsetToTypeMap(item->string_data_off_, DexFile::kDexTypeStringDataItem)) {
return false;
}
// Check ordering between items.
if (previous_item_ != nullptr) {
const DexFile::StringId* prev_item = reinterpret_cast<const DexFile::StringId*>(previous_item_);
const char* prev_str = dex_file_->GetStringData(*prev_item);
const char* str = dex_file_->GetStringData(*item);
if (UNLIKELY(CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(prev_str, str) >= 0)) {
ErrorStringPrintf("Out-of-order string_ids: '%s' then '%s'", prev_str, str);
return false;
}
}
ptr_ += sizeof(DexFile::StringId);
return true;
}
bool DexFileVerifier::CheckInterTypeIdItem() {
const DexFile::TypeId* item = reinterpret_cast<const DexFile::TypeId*>(ptr_);
LOAD_STRING(descriptor, item->descriptor_idx_, "inter_type_id_item descriptor_idx")
// Check that the descriptor is a valid type.
if (UNLIKELY(!IsValidDescriptor(descriptor))) {
ErrorStringPrintf("Invalid type descriptor: '%s'", descriptor);
return false;
}
// Check ordering between items.
if (previous_item_ != nullptr) {
const DexFile::TypeId* prev_item = reinterpret_cast<const DexFile::TypeId*>(previous_item_);
if (UNLIKELY(prev_item->descriptor_idx_ >= item->descriptor_idx_)) {
ErrorStringPrintf("Out-of-order type_ids: %x then %x",
prev_item->descriptor_idx_, item->descriptor_idx_);
return false;
}
}
ptr_ += sizeof(DexFile::TypeId);
return true;
}
bool DexFileVerifier::CheckInterProtoIdItem() {
const DexFile::ProtoId* item = reinterpret_cast<const DexFile::ProtoId*>(ptr_);
LOAD_STRING(shorty, item->shorty_idx_, "inter_proto_id_item shorty_idx")
if (item->parameters_off_ != 0 &&
!CheckOffsetToTypeMap(item->parameters_off_, DexFile::kDexTypeTypeList)) {
return false;
}
// Check the return type and advance the shorty.
LOAD_STRING_BY_TYPE(return_type, item->return_type_idx_, "inter_proto_id_item return_type_idx")
if (!CheckShortyDescriptorMatch(*shorty, return_type, true)) {
return false;
}
shorty++;
DexFileParameterIterator it(*dex_file_, *item);
while (it.HasNext() && *shorty != '\0') {
if (!CheckIndex(it.GetTypeIdx(), dex_file_->NumTypeIds(),
"inter_proto_id_item shorty type_idx")) {
return false;
}
const char* descriptor = it.GetDescriptor();
if (!CheckShortyDescriptorMatch(*shorty, descriptor, false)) {
return false;
}
it.Next();
shorty++;
}
if (UNLIKELY(it.HasNext() || *shorty != '\0')) {
ErrorStringPrintf("Mismatched length for parameters and shorty");
return false;
}
// Check ordering between items. This relies on type_ids being in order.
if (previous_item_ != nullptr) {
const DexFile::ProtoId* prev = reinterpret_cast<const DexFile::ProtoId*>(previous_item_);
if (UNLIKELY(prev->return_type_idx_ > item->return_type_idx_)) {
ErrorStringPrintf("Out-of-order proto_id return types");
return false;
} else if (prev->return_type_idx_ == item->return_type_idx_) {
DexFileParameterIterator curr_it(*dex_file_, *item);
DexFileParameterIterator prev_it(*dex_file_, *prev);
while (curr_it.HasNext() && prev_it.HasNext()) {
uint16_t prev_idx = prev_it.GetTypeIdx();
uint16_t curr_idx = curr_it.GetTypeIdx();
DCHECK_NE(prev_idx, DexFile::kDexNoIndex16);
DCHECK_NE(curr_idx, DexFile::kDexNoIndex16);
if (prev_idx < curr_idx) {
break;
} else if (UNLIKELY(prev_idx > curr_idx)) {
ErrorStringPrintf("Out-of-order proto_id arguments");
return false;
}
prev_it.Next();
curr_it.Next();
}
if (!curr_it.HasNext()) {
// Either a duplicate ProtoId or a ProtoId with a shorter argument list follows
// a ProtoId with a longer one. Both cases are forbidden by the specification.
ErrorStringPrintf("Out-of-order proto_id arguments");
return false;
}
}
}
ptr_ += sizeof(DexFile::ProtoId);
return true;
}
bool DexFileVerifier::CheckInterFieldIdItem() {
const DexFile::FieldId* item = reinterpret_cast<const DexFile::FieldId*>(ptr_);
// Check that the class descriptor is valid.
LOAD_STRING_BY_TYPE(class_descriptor, item->class_idx_, "inter_field_id_item class_idx")
if (UNLIKELY(!IsValidDescriptor(class_descriptor) || class_descriptor[0] != 'L')) {
ErrorStringPrintf("Invalid descriptor for class_idx: '%s'", class_descriptor);
return false;
}
// Check that the type descriptor is a valid field name.
LOAD_STRING_BY_TYPE(type_descriptor, item->type_idx_, "inter_field_id_item type_idx")
if (UNLIKELY(!IsValidDescriptor(type_descriptor) || type_descriptor[0] == 'V')) {
ErrorStringPrintf("Invalid descriptor for type_idx: '%s'", type_descriptor);
return false;
}
// Check that the name is valid.
LOAD_STRING(descriptor, item->name_idx_, "inter_field_id_item name_idx")
if (UNLIKELY(!IsValidMemberName(descriptor))) {
ErrorStringPrintf("Invalid field name: '%s'", descriptor);
return false;
}
// Check ordering between items. This relies on the other sections being in order.
if (previous_item_ != nullptr) {
const DexFile::FieldId* prev_item = reinterpret_cast<const DexFile::FieldId*>(previous_item_);
if (UNLIKELY(prev_item->class_idx_ > item->class_idx_)) {
ErrorStringPrintf("Out-of-order field_ids");
return false;
} else if (prev_item->class_idx_ == item->class_idx_) {
if (UNLIKELY(prev_item->name_idx_ > item->name_idx_)) {
ErrorStringPrintf("Out-of-order field_ids");
return false;
} else if (prev_item->name_idx_ == item->name_idx_) {
if (UNLIKELY(prev_item->type_idx_ >= item->type_idx_)) {
ErrorStringPrintf("Out-of-order field_ids");
return false;
}
}
}
}
ptr_ += sizeof(DexFile::FieldId);
return true;
}
bool DexFileVerifier::CheckInterMethodIdItem() {
const DexFile::MethodId* item = reinterpret_cast<const DexFile::MethodId*>(ptr_);
// Check that the class descriptor is a valid reference name.
LOAD_STRING_BY_TYPE(class_descriptor, item->class_idx_, "inter_method_id_item class_idx")
if (UNLIKELY(!IsValidDescriptor(class_descriptor) || (class_descriptor[0] != 'L' &&
class_descriptor[0] != '['))) {
ErrorStringPrintf("Invalid descriptor for class_idx: '%s'", class_descriptor);
return false;
}
// Check that the name is valid.
LOAD_STRING(descriptor, item->name_idx_, "inter_method_id_item name_idx")
if (UNLIKELY(!IsValidMemberName(descriptor))) {
ErrorStringPrintf("Invalid method name: '%s'", descriptor);
return false;
}
// Check that the proto id is valid.
if (UNLIKELY(!CheckIndex(item->proto_idx_, dex_file_->NumProtoIds(),
"inter_method_id_item proto_idx"))) {
return false;
}
// Check ordering between items. This relies on the other sections being in order.
if (previous_item_ != nullptr) {
const DexFile::MethodId* prev_item = reinterpret_cast<const DexFile::MethodId*>(previous_item_);
if (UNLIKELY(prev_item->class_idx_ > item->class_idx_)) {
ErrorStringPrintf("Out-of-order method_ids");
return false;
} else if (prev_item->class_idx_ == item->class_idx_) {
if (UNLIKELY(prev_item->name_idx_ > item->name_idx_)) {
ErrorStringPrintf("Out-of-order method_ids");
return false;
} else if (prev_item->name_idx_ == item->name_idx_) {
if (UNLIKELY(prev_item->proto_idx_ >= item->proto_idx_)) {
ErrorStringPrintf("Out-of-order method_ids");
return false;
}
}
}
}
ptr_ += sizeof(DexFile::MethodId);
return true;
}
bool DexFileVerifier::CheckInterClassDefItem() {
const DexFile::ClassDef* item = reinterpret_cast<const DexFile::ClassDef*>(ptr_);
// Check for duplicate class def.
if (defined_classes_.find(item->class_idx_) != defined_classes_.end()) {
ErrorStringPrintf("Redefinition of class with type idx: '%d'", item->class_idx_);
return false;
}
defined_classes_.insert(item->class_idx_);
LOAD_STRING_BY_TYPE(class_descriptor, item->class_idx_, "inter_class_def_item class_idx")
if (UNLIKELY(!IsValidDescriptor(class_descriptor) || class_descriptor[0] != 'L')) {
ErrorStringPrintf("Invalid class descriptor: '%s'", class_descriptor);
return false;
}
// Only allow non-runtime modifiers.
if ((item->access_flags_ & ~kAccJavaFlagsMask) != 0) {
ErrorStringPrintf("Invalid class flags: '%d'", item->access_flags_);
return false;
}
if (item->interfaces_off_ != 0 &&
!CheckOffsetToTypeMap(item->interfaces_off_, DexFile::kDexTypeTypeList)) {
return false;
}
if (item->annotations_off_ != 0 &&
!CheckOffsetToTypeMap(item->annotations_off_, DexFile::kDexTypeAnnotationsDirectoryItem)) {
return false;
}
if (item->class_data_off_ != 0 &&
!CheckOffsetToTypeMap(item->class_data_off_, DexFile::kDexTypeClassDataItem)) {
return false;
}
if (item->static_values_off_ != 0 &&
!CheckOffsetToTypeMap(item->static_values_off_, DexFile::kDexTypeEncodedArrayItem)) {
return false;
}
if (item->superclass_idx_ != DexFile::kDexNoIndex16) {
if (header_->GetVersion() >= DexFile::kClassDefinitionOrderEnforcedVersion) {
// Check that a class does not inherit from itself directly (by having
// the same type idx as its super class).
if (UNLIKELY(item->superclass_idx_ == item->class_idx_)) {
ErrorStringPrintf("Class with same type idx as its superclass: '%d'", item->class_idx_);
return false;
}
// Check that a class is defined after its super class (if the
// latter is defined in the same Dex file).
const DexFile::ClassDef* superclass_def = dex_file_->FindClassDef(item->superclass_idx_);
if (superclass_def != nullptr) {
// The superclass is defined in this Dex file.
if (superclass_def > item) {
// ClassDef item for super class appearing after the class' ClassDef item.
ErrorStringPrintf("Invalid class definition ordering:"
" class with type idx: '%d' defined before"
" superclass with type idx: '%d'",
item->class_idx_,
item->superclass_idx_);
return false;
}
}
}
LOAD_STRING_BY_TYPE(superclass_descriptor, item->superclass_idx_,
"inter_class_def_item superclass_idx")
if (UNLIKELY(!IsValidDescriptor(superclass_descriptor) || superclass_descriptor[0] != 'L')) {
ErrorStringPrintf("Invalid superclass: '%s'", superclass_descriptor);
return false;
}
}
// Check interfaces.
const DexFile::TypeList* interfaces = dex_file_->GetInterfacesList(*item);
if (interfaces != nullptr) {
uint32_t size = interfaces->Size();
for (uint32_t i = 0; i < size; i++) {
if (header_->GetVersion() >= DexFile::kClassDefinitionOrderEnforcedVersion) {
// Check that a class does not implement itself directly (by having the
// same type idx as one of its immediate implemented interfaces).
if (UNLIKELY(interfaces->GetTypeItem(i).type_idx_ == item->class_idx_)) {
ErrorStringPrintf("Class with same type idx as implemented interface: '%d'",
item->class_idx_);
return false;
}
// Check that a class is defined after the interfaces it implements
// (if they are defined in the same Dex file).
const DexFile::ClassDef* interface_def =
dex_file_->FindClassDef(interfaces->GetTypeItem(i).type_idx_);
if (interface_def != nullptr) {
// The interface is defined in this Dex file.
if (interface_def > item) {
// ClassDef item for interface appearing after the class' ClassDef item.
ErrorStringPrintf("Invalid class definition ordering:"
" class with type idx: '%d' defined before"
" implemented interface with type idx: '%d'",
item->class_idx_,
interfaces->GetTypeItem(i).type_idx_);
return false;
}
}
}
// Ensure that the interface refers to a class (not an array nor a primitive type).
LOAD_STRING_BY_TYPE(inf_descriptor, interfaces->GetTypeItem(i).type_idx_,
"inter_class_def_item interface type_idx")
if (UNLIKELY(!IsValidDescriptor(inf_descriptor) || inf_descriptor[0] != 'L')) {
ErrorStringPrintf("Invalid interface: '%s'", inf_descriptor);
return false;
}
}
/*
* Ensure that there are no duplicates. This is an O(N^2) test, but in
* practice the number of interfaces implemented by any given class is low.
*/
for (uint32_t i = 1; i < size; i++) {
uint32_t idx1 = interfaces->GetTypeItem(i).type_idx_;
for (uint32_t j =0; j < i; j++) {
uint32_t idx2 = interfaces->GetTypeItem(j).type_idx_;
if (UNLIKELY(idx1 == idx2)) {
ErrorStringPrintf("Duplicate interface: '%s'", dex_file_->StringByTypeIdx(idx1));
return false;
}
}
}
}
// Check that references in class_data_item are to the right class.
if (item->class_data_off_ != 0) {
const uint8_t* data = begin_ + item->class_data_off_;
bool success;
uint16_t data_definer = FindFirstClassDataDefiner(data, &success);
if (!success) {
return false;
}
if (UNLIKELY((data_definer != item->class_idx_) && (data_definer != DexFile::kDexNoIndex16))) {
ErrorStringPrintf("Invalid class_data_item");
return false;
}
}
// Check that references in annotations_directory_item are to right class.
if (item->annotations_off_ != 0) {
// annotations_off_ is supposed to be aligned by 4.
if (!IsAlignedParam(item->annotations_off_, 4)) {
ErrorStringPrintf("Invalid annotations_off_, not aligned by 4");
return false;
}
const uint8_t* data = begin_ + item->annotations_off_;
bool success;
uint16_t annotations_definer = FindFirstAnnotationsDirectoryDefiner(data, &success);
if (!success) {
return false;
}
if (UNLIKELY((annotations_definer != item->class_idx_) &&
(annotations_definer != DexFile::kDexNoIndex16))) {
ErrorStringPrintf("Invalid annotations_directory_item");
return false;
}
}
ptr_ += sizeof(DexFile::ClassDef);
return true;
}
bool DexFileVerifier::CheckInterAnnotationSetRefList() {
const DexFile::AnnotationSetRefList* list =
reinterpret_cast<const DexFile::AnnotationSetRefList*>(ptr_);
const DexFile::AnnotationSetRefItem* item = list->list_;
uint32_t count = list->size_;
while (count--) {
if (item->annotations_off_ != 0 &&
!CheckOffsetToTypeMap(item->annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
return false;
}
item++;
}
ptr_ = reinterpret_cast<const uint8_t*>(item);
return true;
}
bool DexFileVerifier::CheckInterAnnotationSetItem() {
const DexFile::AnnotationSetItem* set = reinterpret_cast<const DexFile::AnnotationSetItem*>(ptr_);
const uint32_t* offsets = set->entries_;
uint32_t count = set->size_;
uint32_t last_idx = 0;
for (uint32_t i = 0; i < count; i++) {
if (*offsets != 0 && !CheckOffsetToTypeMap(*offsets, DexFile::kDexTypeAnnotationItem)) {
return false;
}
// Get the annotation from the offset and the type index for the annotation.
const DexFile::AnnotationItem* annotation =
reinterpret_cast<const DexFile::AnnotationItem*>(begin_ + *offsets);
const uint8_t* data = annotation->annotation_;
uint32_t idx = DecodeUnsignedLeb128(&data);
if (UNLIKELY(last_idx >= idx && i != 0)) {
ErrorStringPrintf("Out-of-order entry types: %x then %x", last_idx, idx);
return false;
}
last_idx = idx;
offsets++;
}
ptr_ = reinterpret_cast<const uint8_t*>(offsets);
return true;
}
bool DexFileVerifier::CheckInterClassDataItem() {
ClassDataItemIterator it(*dex_file_, ptr_);
bool success;
uint16_t defining_class = FindFirstClassDataDefiner(ptr_, &success);
if (!success) {
return false;
}
for (; it.HasNextStaticField() || it.HasNextInstanceField(); it.Next()) {
LOAD_FIELD(field, it.GetMemberIndex(), "inter_class_data_item field_id", return false)
if (UNLIKELY(field->class_idx_ != defining_class)) {
ErrorStringPrintf("Mismatched defining class for class_data_item field");
return false;
}
}
for (; it.HasNextDirectMethod() || it.HasNextVirtualMethod(); it.Next()) {
uint32_t code_off = it.GetMethodCodeItemOffset();
if (code_off != 0 && !CheckOffsetToTypeMap(code_off, DexFile::kDexTypeCodeItem)) {
return false;
}
LOAD_METHOD(method, it.GetMemberIndex(), "inter_class_data_item method_id", return false)
if (UNLIKELY(method->class_idx_ != defining_class)) {
ErrorStringPrintf("Mismatched defining class for class_data_item method");
return false;
}
}
ptr_ = it.EndDataPointer();
return true;
}
bool DexFileVerifier::CheckInterAnnotationsDirectoryItem() {
const DexFile::AnnotationsDirectoryItem* item =
reinterpret_cast<const DexFile::AnnotationsDirectoryItem*>(ptr_);
bool success;
uint16_t defining_class = FindFirstAnnotationsDirectoryDefiner(ptr_, &success);
if (!success) {
return false;
}
if (item->class_annotations_off_ != 0 &&
!CheckOffsetToTypeMap(item->class_annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
return false;
}
// Field annotations follow immediately after the annotations directory.
const DexFile::FieldAnnotationsItem* field_item =
reinterpret_cast<const DexFile::FieldAnnotationsItem*>(item + 1);
uint32_t field_count = item->fields_size_;
for (uint32_t i = 0; i < field_count; i++) {
LOAD_FIELD(field, field_item->field_idx_, "inter_annotations_directory_item field_id",
return false)
if (UNLIKELY(field->class_idx_ != defining_class)) {
ErrorStringPrintf("Mismatched defining class for field_annotation");
return false;
}
if (!CheckOffsetToTypeMap(field_item->annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
return false;
}
field_item++;
}
// Method annotations follow immediately after field annotations.
const DexFile::MethodAnnotationsItem* method_item =
reinterpret_cast<const DexFile::MethodAnnotationsItem*>(field_item);
uint32_t method_count = item->methods_size_;
for (uint32_t i = 0; i < method_count; i++) {
LOAD_METHOD(method, method_item->method_idx_, "inter_annotations_directory_item method_id",
return false)
if (UNLIKELY(method->class_idx_ != defining_class)) {
ErrorStringPrintf("Mismatched defining class for method_annotation");
return false;
}
if (!CheckOffsetToTypeMap(method_item->annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
return false;
}
method_item++;
}
// Parameter annotations follow immediately after method annotations.
const DexFile::ParameterAnnotationsItem* parameter_item =
reinterpret_cast<const DexFile::ParameterAnnotationsItem*>(method_item);
uint32_t parameter_count = item->parameters_size_;
for (uint32_t i = 0; i < parameter_count; i++) {
LOAD_METHOD(parameter_method, parameter_item->method_idx_,
"inter_annotations_directory_item parameter method_id", return false)
if (UNLIKELY(parameter_method->class_idx_ != defining_class)) {
ErrorStringPrintf("Mismatched defining class for parameter_annotation");
return false;
}
if (!CheckOffsetToTypeMap(parameter_item->annotations_off_,
DexFile::kDexTypeAnnotationSetRefList)) {
return false;
}
parameter_item++;
}
ptr_ = reinterpret_cast<const uint8_t*>(parameter_item);
return true;
}
bool DexFileVerifier::CheckInterSectionIterate(size_t offset, uint32_t count, uint16_t type) {
// Get the right alignment mask for the type of section.
size_t alignment_mask;
switch (type) {
case DexFile::kDexTypeClassDataItem:
alignment_mask = sizeof(uint8_t) - 1;
break;
default:
alignment_mask = sizeof(uint32_t) - 1;
break;
}
// Iterate through the items in the section.
previous_item_ = nullptr;
for (uint32_t i = 0; i < count; i++) {
uint32_t new_offset = (offset + alignment_mask) & ~alignment_mask;
ptr_ = begin_ + new_offset;
const uint8_t* prev_ptr = ptr_;
// Check depending on the section type.
switch (type) {
case DexFile::kDexTypeStringIdItem: {
if (!CheckInterStringIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeTypeIdItem: {
if (!CheckInterTypeIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeProtoIdItem: {
if (!CheckInterProtoIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeFieldIdItem: {
if (!CheckInterFieldIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeMethodIdItem: {
if (!CheckInterMethodIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeClassDefItem: {
if (!CheckInterClassDefItem()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationSetRefList: {
if (!CheckInterAnnotationSetRefList()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationSetItem: {
if (!CheckInterAnnotationSetItem()) {
return false;
}
break;
}
case DexFile::kDexTypeClassDataItem: {
if (!CheckInterClassDataItem()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationsDirectoryItem: {
if (!CheckInterAnnotationsDirectoryItem()) {
return false;
}
break;
}
default:
ErrorStringPrintf("Unknown map item type %x", type);
return false;
}
previous_item_ = prev_ptr;
offset = ptr_ - begin_;
}
return true;
}
bool DexFileVerifier::CheckInterSection() {
const DexFile::MapList* map = reinterpret_cast<const DexFile::MapList*>(begin_ + header_->map_off_);
const DexFile::MapItem* item = map->list_;
uint32_t count = map->size_;
// Cross check the items listed in the map.
while (count--) {
uint32_t section_offset = item->offset_;
uint32_t section_count = item->size_;
uint16_t type = item->type_;
switch (type) {
case DexFile::kDexTypeHeaderItem:
case DexFile::kDexTypeMapList:
case DexFile::kDexTypeTypeList:
case DexFile::kDexTypeCodeItem:
case DexFile::kDexTypeStringDataItem:
case DexFile::kDexTypeDebugInfoItem:
case DexFile::kDexTypeAnnotationItem:
case DexFile::kDexTypeEncodedArrayItem:
break;
case DexFile::kDexTypeStringIdItem:
case DexFile::kDexTypeTypeIdItem:
case DexFile::kDexTypeProtoIdItem:
case DexFile::kDexTypeFieldIdItem:
case DexFile::kDexTypeMethodIdItem:
case DexFile::kDexTypeClassDefItem:
case DexFile::kDexTypeAnnotationSetRefList:
case DexFile::kDexTypeAnnotationSetItem:
case DexFile::kDexTypeClassDataItem:
case DexFile::kDexTypeAnnotationsDirectoryItem: {
if (!CheckInterSectionIterate(section_offset, section_count, type)) {
return false;
}
break;
}
default:
ErrorStringPrintf("Unknown map item type %x", type);
return false;
}
item++;
}
return true;
}
bool DexFileVerifier::Verify() {
// Check the header.
if (!CheckHeader()) {
return false;
}
// Check the map section.
if (!CheckMap()) {
return false;
}
// Check structure within remaining sections.
if (!CheckIntraSection()) {
return false;
}
// Check references from one section to another.
if (!CheckInterSection()) {
return false;
}
return true;
}
void DexFileVerifier::ErrorStringPrintf(const char* fmt, ...) {
va_list ap;
va_start(ap, fmt);
DCHECK(failure_reason_.empty()) << failure_reason_;
failure_reason_ = StringPrintf("Failure to verify dex file '%s': ", location_);
StringAppendV(&failure_reason_, fmt, ap);
va_end(ap);
}
// Fields and methods may have only one of public/protected/private.
static bool CheckAtMostOneOfPublicProtectedPrivate(uint32_t flags) {
size_t count = (((flags & kAccPublic) == 0) ? 0 : 1) +
(((flags & kAccProtected) == 0) ? 0 : 1) +
(((flags & kAccPrivate) == 0) ? 0 : 1);
return count <= 1;
}
// Helper functions to retrieve names from the dex file. We do not want to rely on DexFile
// functionality, as we're still verifying the dex file. begin and header correspond to the
// underscored variants in the DexFileVerifier.
static std::string GetStringOrError(const uint8_t* const begin,
const DexFile::Header* const header,
uint32_t string_idx) {
// The `string_idx` is not guaranteed to be valid yet.
if (header->string_ids_size_ <= string_idx) {
return "(error)";
}
const DexFile::StringId* string_id =
reinterpret_cast<const DexFile::StringId*>(begin + header->string_ids_off_) + string_idx;
// Assume that the data is OK at this point. String data has been checked at this point.
const uint8_t* ptr = begin + string_id->string_data_off_;
DecodeUnsignedLeb128(&ptr);
return reinterpret_cast<const char*>(ptr);
}
static std::string GetClassOrError(const uint8_t* const begin,
const DexFile::Header* const header,
uint32_t class_idx) {
// The `class_idx` is either `FieldId::class_idx_` or `MethodId::class_idx_` and
// it has already been checked in `DexFileVerifier::CheckClassDataItemField()`
// or `DexFileVerifier::CheckClassDataItemMethod()`, respectively, to match
// a valid defining class.
CHECK_LT(class_idx, header->type_ids_size_);
const DexFile::TypeId* type_id =
reinterpret_cast<const DexFile::TypeId*>(begin + header->type_ids_off_) + class_idx;
// Assume that the data is OK at this point. Type id offsets have been checked at this point.
return GetStringOrError(begin, header, type_id->descriptor_idx_);
}
static std::string GetFieldDescriptionOrError(const uint8_t* const begin,
const DexFile::Header* const header,
uint32_t idx) {
// The `idx` has already been checked in `DexFileVerifier::CheckClassDataItemField()`.
CHECK_LT(idx, header->field_ids_size_);
const DexFile::FieldId* field_id =
reinterpret_cast<const DexFile::FieldId*>(begin + header->field_ids_off_) + idx;
// Assume that the data is OK at this point. Field id offsets have been checked at this point.
std::string class_name = GetClassOrError(begin, header, field_id->class_idx_);
std::string field_name = GetStringOrError(begin, header, field_id->name_idx_);
return class_name + "." + field_name;
}
static std::string GetMethodDescriptionOrError(const uint8_t* const begin,
const DexFile::Header* const header,
uint32_t idx) {
// The `idx` has already been checked in `DexFileVerifier::CheckClassDataItemMethod()`.
CHECK_LT(idx, header->method_ids_size_);
const DexFile::MethodId* method_id =
reinterpret_cast<const DexFile::MethodId*>(begin + header->method_ids_off_) + idx;
// Assume that the data is OK at this point. Method id offsets have been checked at this point.
std::string class_name = GetClassOrError(begin, header, method_id->class_idx_);
std::string method_name = GetStringOrError(begin, header, method_id->name_idx_);
return class_name + "." + method_name;
}
bool DexFileVerifier::CheckFieldAccessFlags(uint32_t idx,
uint32_t field_access_flags,
uint32_t class_access_flags,
std::string* error_msg) {
// Generally sort out >16-bit flags.
if ((field_access_flags & ~kAccJavaFlagsMask) != 0) {
*error_msg = StringPrintf("Bad field access_flags for %s: %x(%s)",
GetFieldDescriptionOrError(begin_, header_, idx).c_str(),
field_access_flags,
PrettyJavaAccessFlags(field_access_flags).c_str());
return false;
}
// Flags allowed on fields, in general. Other lower-16-bit flags are to be ignored.
constexpr uint32_t kFieldAccessFlags = kAccPublic |
kAccPrivate |
kAccProtected |
kAccStatic |
kAccFinal |
kAccVolatile |
kAccTransient |
kAccSynthetic |
kAccEnum;
// Fields may have only one of public/protected/final.
if (!CheckAtMostOneOfPublicProtectedPrivate(field_access_flags)) {
*error_msg = StringPrintf("Field may have only one of public/protected/private, %s: %x(%s)",
GetFieldDescriptionOrError(begin_, header_, idx).c_str(),
field_access_flags,
PrettyJavaAccessFlags(field_access_flags).c_str());
return false;
}
// Interfaces have a pretty restricted list.
if ((class_access_flags & kAccInterface) != 0) {
// Interface fields must be public final static.
constexpr uint32_t kPublicFinalStatic = kAccPublic | kAccFinal | kAccStatic;
if ((field_access_flags & kPublicFinalStatic) != kPublicFinalStatic) {
*error_msg = StringPrintf("Interface field is not public final static, %s: %x(%s)",
GetFieldDescriptionOrError(begin_, header_, idx).c_str(),
field_access_flags,
PrettyJavaAccessFlags(field_access_flags).c_str());
if (header_->GetVersion() >= DexFile::kDefaultMethodsVersion) {
return false;
} else {
// Allow in older versions, but warn.
LOG(WARNING) << "This dex file is invalid and will be rejected in the future. Error is: "
<< *error_msg;
}
}
// Interface fields may be synthetic, but may not have other flags.
constexpr uint32_t kDisallowed = ~(kPublicFinalStatic | kAccSynthetic);
if ((field_access_flags & kFieldAccessFlags & kDisallowed) != 0) {
*error_msg = StringPrintf("Interface field has disallowed flag, %s: %x(%s)",
GetFieldDescriptionOrError(begin_, header_, idx).c_str(),
field_access_flags,
PrettyJavaAccessFlags(field_access_flags).c_str());
if (header_->GetVersion() >= DexFile::kDefaultMethodsVersion) {
return false;
} else {
// Allow in older versions, but warn.
LOG(WARNING) << "This dex file is invalid and will be rejected in the future. Error is: "
<< *error_msg;
}
}
return true;
}
// Volatile fields may not be final.
constexpr uint32_t kVolatileFinal = kAccVolatile | kAccFinal;
if ((field_access_flags & kVolatileFinal) == kVolatileFinal) {
*error_msg = StringPrintf("Fields may not be volatile and final: %s",
GetFieldDescriptionOrError(begin_, header_, idx).c_str());
return false;
}
return true;
}
// Try to find the name of the method with the given index. We do not want to rely on DexFile
// infrastructure at this point, so do it all by hand. begin and header correspond to begin_ and
// header_ of the DexFileVerifier. str will contain the pointer to the method name on success
// (flagged by the return value), otherwise error_msg will contain an error string.
static bool FindMethodName(uint32_t method_index,
const uint8_t* begin,
const DexFile::Header* header,
const char** str,
std::string* error_msg) {
if (method_index >= header->method_ids_size_) {
*error_msg = "Method index not available for method flags verification";
return false;
}
uint32_t string_idx =
(reinterpret_cast<const DexFile::MethodId*>(begin + header->method_ids_off_) +
method_index)->name_idx_;
if (string_idx >= header->string_ids_size_) {
*error_msg = "String index not available for method flags verification";
return false;
}
uint32_t string_off =
(reinterpret_cast<const DexFile::StringId*>(begin + header->string_ids_off_) + string_idx)->
string_data_off_;
if (string_off >= header->file_size_) {
*error_msg = "String offset out of bounds for method flags verification";
return false;
}
const uint8_t* str_data_ptr = begin + string_off;
DecodeUnsignedLeb128(&str_data_ptr);
*str = reinterpret_cast<const char*>(str_data_ptr);
return true;
}
bool DexFileVerifier::CheckMethodAccessFlags(uint32_t method_index,
uint32_t method_access_flags,
uint32_t class_access_flags,
bool has_code,
bool expect_direct,
std::string* error_msg) {
// Generally sort out >16-bit flags, except dex knows Constructor and DeclaredSynchronized.
constexpr uint32_t kAllMethodFlags =
kAccJavaFlagsMask | kAccConstructor | kAccDeclaredSynchronized;
if ((method_access_flags & ~kAllMethodFlags) != 0) {
*error_msg = StringPrintf("Bad method access_flags for %s: %x",
GetMethodDescriptionOrError(begin_, header_, method_index).c_str(),
method_access_flags);
return false;
}
// Flags allowed on fields, in general. Other lower-16-bit flags are to be ignored.
constexpr uint32_t kMethodAccessFlags = kAccPublic |
kAccPrivate |
kAccProtected |
kAccStatic |
kAccFinal |
kAccSynthetic |
kAccSynchronized |
kAccBridge |
kAccVarargs |
kAccNative |
kAccAbstract |
kAccStrict;
// Methods may have only one of public/protected/final.
if (!CheckAtMostOneOfPublicProtectedPrivate(method_access_flags)) {
*error_msg = StringPrintf("Method may have only one of public/protected/private, %s: %x",
GetMethodDescriptionOrError(begin_, header_, method_index).c_str(),
method_access_flags);
return false;
}
// Try to find the name, to check for constructor properties.
const char* str;
if (!FindMethodName(method_index, begin_, header_, &str, error_msg)) {
return false;
}
bool is_init_by_name = false;
constexpr const char* kInitName = "<init>";
size_t str_offset = (reinterpret_cast<const uint8_t*>(str) - begin_);
if (header_->file_size_ - str_offset >= sizeof(kInitName)) {
is_init_by_name = strcmp(kInitName, str) == 0;
}
bool is_clinit_by_name = false;
constexpr const char* kClinitName = "<clinit>";
if (header_->file_size_ - str_offset >= sizeof(kClinitName)) {
is_clinit_by_name = strcmp(kClinitName, str) == 0;
}
bool is_constructor = is_init_by_name || is_clinit_by_name;
// Only methods named "<clinit>" or "<init>" may be marked constructor. Note: we cannot enforce
// the reverse for backwards compatibility reasons.
if (((method_access_flags & kAccConstructor) != 0) && !is_constructor) {
*error_msg =
StringPrintf("Method %" PRIu32 "(%s) is marked constructor, but doesn't match name",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str());
return false;
}
// Check that the static constructor (= static initializer) is named "<clinit>" and that the
// instance constructor is called "<init>".
if (is_constructor) {
bool is_static = (method_access_flags & kAccStatic) != 0;
if (is_static ^ is_clinit_by_name) {
*error_msg = StringPrintf("Constructor %" PRIu32 "(%s) is not flagged correctly wrt/ static.",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str());
if (header_->GetVersion() >= DexFile::kDefaultMethodsVersion) {
return false;
} else {
// Allow in older versions, but warn.
LOG(WARNING) << "This dex file is invalid and will be rejected in the future. Error is: "
<< *error_msg;
}
}
}
// Check that static and private methods, as well as constructors, are in the direct methods list,
// and other methods in the virtual methods list.
bool is_direct = (method_access_flags & (kAccStatic | kAccPrivate)) != 0 || is_constructor;
if (is_direct != expect_direct) {
*error_msg = StringPrintf("Direct/virtual method %" PRIu32 "(%s) not in expected list %d",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str(),
expect_direct);
return false;
}
// From here on out it is easier to mask out the bits we're supposed to ignore.
method_access_flags &= kMethodAccessFlags;
// Interfaces are special.
if ((class_access_flags & kAccInterface) != 0) {
// Non-static interface methods must be public or private.
uint32_t desired_flags = (kAccPublic | kAccStatic);
if (dex_file_->GetVersion() >= DexFile::kDefaultMethodsVersion) {
desired_flags |= kAccPrivate;
}
if ((method_access_flags & desired_flags) == 0) {
*error_msg = StringPrintf("Interface virtual method %" PRIu32 "(%s) is not public",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str());
if (header_->GetVersion() >= DexFile::kDefaultMethodsVersion) {
return false;
} else {
// Allow in older versions, but warn.
LOG(WARNING) << "This dex file is invalid and will be rejected in the future. Error is: "
<< *error_msg;
}
}
}
// If there aren't any instructions, make sure that's expected.
if (!has_code) {
// Only native or abstract methods may not have code.
if ((method_access_flags & (kAccNative | kAccAbstract)) == 0) {
*error_msg = StringPrintf("Method %" PRIu32 "(%s) has no code, but is not marked native or "
"abstract",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str());
return false;
}
// Constructors must always have code.
if (is_constructor) {
*error_msg = StringPrintf("Constructor %u(%s) must not be abstract or native",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str());
if (header_->GetVersion() >= DexFile::kDefaultMethodsVersion) {
return false;
} else {
// Allow in older versions, but warn.
LOG(WARNING) << "This dex file is invalid and will be rejected in the future. Error is: "
<< *error_msg;
}
}
if ((method_access_flags & kAccAbstract) != 0) {
// Abstract methods are not allowed to have the following flags.
constexpr uint32_t kForbidden =
kAccPrivate | kAccStatic | kAccFinal | kAccNative | kAccStrict | kAccSynchronized;
if ((method_access_flags & kForbidden) != 0) {
*error_msg = StringPrintf("Abstract method %" PRIu32 "(%s) has disallowed access flags %x",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str(),
method_access_flags);
return false;
}
// Abstract methods should be in an abstract class or interface.
if ((class_access_flags & (kAccInterface | kAccAbstract)) == 0) {
LOG(WARNING) << "Method " << GetMethodDescriptionOrError(begin_, header_, method_index)
<< " is abstract, but the declaring class is neither abstract nor an "
<< "interface in dex file "
<< dex_file_->GetLocation();
}
}
// Interfaces are special.
if ((class_access_flags & kAccInterface) != 0) {
// Interface methods without code must be abstract.
if ((method_access_flags & (kAccPublic | kAccAbstract)) != (kAccPublic | kAccAbstract)) {
*error_msg = StringPrintf("Interface method %" PRIu32 "(%s) is not public and abstract",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str());
if (header_->GetVersion() >= DexFile::kDefaultMethodsVersion) {
return false;
} else {
// Allow in older versions, but warn.
LOG(WARNING) << "This dex file is invalid and will be rejected in the future. Error is: "
<< *error_msg;
}
}
// At this point, we know the method is public and abstract. This means that all the checks
// for invalid combinations above applies. In addition, interface methods must not be
// protected. This is caught by the check for only-one-of-public-protected-private.
}
return true;
}
// When there's code, the method must not be native or abstract.
if ((method_access_flags & (kAccNative | kAccAbstract)) != 0) {
*error_msg = StringPrintf("Method %" PRIu32 "(%s) has code, but is marked native or abstract",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str());
return false;
}
// Instance constructors must not be synchronized and a few other flags.
if (is_init_by_name) {
static constexpr uint32_t kInitAllowed =
kAccPrivate | kAccProtected | kAccPublic | kAccStrict | kAccVarargs | kAccSynthetic;
if ((method_access_flags & ~kInitAllowed) != 0) {
*error_msg = StringPrintf("Constructor %" PRIu32 "(%s) flagged inappropriately %x",
method_index,
GetMethodDescriptionOrError(begin_, header_, method_index).c_str(),
method_access_flags);
return false;
}
}
return true;
}
} // namespace art