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android / platform / art / a3b75aea04f875da146c3ef71912e95f5ee903ac / . / libdexfile / dex / dex_file_verifier.cc
blob: 1d3327131194a8d6845118c2983493240cb86659 [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 <algorithm>
#include <bitset>
#include <limits>
#include <memory>
#include "android-base/logging.h"
#include "android-base/macros.h"
#include "android-base/stringprintf.h"
#include "base/hash_map.h"
#include "base/leb128.h"
#include "base/safe_map.h"
#include "class_accessor-inl.h"
#include "code_item_accessors-inl.h"
#include "descriptors_names.h"
#include "dex_file-inl.h"
#include "dex_file_types.h"
#include "modifiers.h"
#include "utf-inl.h"
namespace art {
namespace dex {
using android::base::StringAppendV;
using android::base::StringPrintf;
namespace {
constexpr uint32_t kTypeIdLimit = std::numeric_limits<uint16_t>::max();
constexpr bool IsValidOrNoTypeId(uint16_t low, uint16_t high) {
return (high == 0) || ((high == 0xffffU) && (low == 0xffffU));
}
constexpr bool IsValidTypeId(uint16_t low ATTRIBUTE_UNUSED, uint16_t high) {
return (high == 0);
}
constexpr uint32_t MapTypeToBitMask(DexFile::MapItemType map_item_type) {
switch (map_item_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::kDexTypeCallSiteIdItem: return 1 << 7;
case DexFile::kDexTypeMethodHandleItem: return 1 << 8;
case DexFile::kDexTypeMapList: return 1 << 9;
case DexFile::kDexTypeTypeList: return 1 << 10;
case DexFile::kDexTypeAnnotationSetRefList: return 1 << 11;
case DexFile::kDexTypeAnnotationSetItem: return 1 << 12;
case DexFile::kDexTypeClassDataItem: return 1 << 13;
case DexFile::kDexTypeCodeItem: return 1 << 14;
case DexFile::kDexTypeStringDataItem: return 1 << 15;
case DexFile::kDexTypeDebugInfoItem: return 1 << 16;
case DexFile::kDexTypeAnnotationItem: return 1 << 17;
case DexFile::kDexTypeEncodedArrayItem: return 1 << 18;
case DexFile::kDexTypeAnnotationsDirectoryItem: return 1 << 19;
case DexFile::kDexTypeHiddenapiClassData: return 1 << 20;
}
return 0;
}
constexpr bool IsDataSectionType(DexFile::MapItemType map_item_type) {
switch (map_item_type) {
case DexFile::kDexTypeHeaderItem:
case DexFile::kDexTypeStringIdItem:
case DexFile::kDexTypeTypeIdItem:
case DexFile::kDexTypeProtoIdItem:
case DexFile::kDexTypeFieldIdItem:
case DexFile::kDexTypeMethodIdItem:
case DexFile::kDexTypeClassDefItem:
return false;
case DexFile::kDexTypeCallSiteIdItem:
case DexFile::kDexTypeMethodHandleItem:
case DexFile::kDexTypeMapList:
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:
case DexFile::kDexTypeHiddenapiClassData:
return true;
}
return true;
}
// Fields and methods may have only one of public/protected/private.
ALWAYS_INLINE
constexpr bool CheckAtMostOneOfPublicProtectedPrivate(uint32_t flags) {
// Semantically we want 'return POPCOUNT(flags & kAcc) <= 1;'.
static_assert(IsPowerOfTwo(0), "0 not marked as power of two");
static_assert(IsPowerOfTwo(kAccPublic), "kAccPublic not marked as power of two");
static_assert(IsPowerOfTwo(kAccProtected), "kAccProtected not marked as power of two");
static_assert(IsPowerOfTwo(kAccPrivate), "kAccPrivate not marked as power of two");
return IsPowerOfTwo(flags & (kAccPublic | kAccProtected | kAccPrivate));
}
// 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.
std::string GetString(const uint8_t* const begin,
const DexFile::Header* const header,
dex::StringIndex string_idx) {
// All sources of the `string_idx` have already been checked in CheckIntraSection().
DCHECK_LT(string_idx.index_, header->string_ids_size_);
const dex::StringId* string_id =
reinterpret_cast<const dex::StringId*>(begin + header->string_ids_off_) + string_idx.index_;
// The string offset has been checked at the start of `CheckInterSection()`
// to point to a string data item checked by `CheckIntraSection()`.
const uint8_t* ptr = begin + string_id->string_data_off_;
DecodeUnsignedLeb128(&ptr); // Ignore the result.
return reinterpret_cast<const char*>(ptr);
}
std::string GetClass(const uint8_t* const begin,
const DexFile::Header* const header,
dex::TypeIndex class_idx) {
// All sources of `class_idx` have already been checked in CheckIntraSection().
CHECK_LT(class_idx.index_, header->type_ids_size_);
const dex::TypeId* type_id =
reinterpret_cast<const dex::TypeId*>(begin + header->type_ids_off_) + class_idx.index_;
// The `type_id->descriptor_idx_` has already been checked in CheckIntraTypeIdItem().
// However, it may not have been checked to be a valid descriptor, so return the raw
// string without converting with `PrettyDescriptor()`.
return GetString(begin, header, type_id->descriptor_idx_);
}
std::string GetFieldDescription(const uint8_t* const begin,
const DexFile::Header* const header,
uint32_t idx) {
// The `idx` has already been checked in `DexFileVerifier::CheckIntraClassDataItemFields()`.
CHECK_LT(idx, header->field_ids_size_);
const dex::FieldId* field_id =
reinterpret_cast<const dex::FieldId*>(begin + header->field_ids_off_) + idx;
// Indexes in `*field_id` have already been checked in CheckIntraFieldIdItem().
std::string class_name = GetClass(begin, header, field_id->class_idx_);
std::string field_name = GetString(begin, header, field_id->name_idx_);
return class_name + "." + field_name;
}
std::string GetMethodDescription(const uint8_t* const begin,
const DexFile::Header* const header,
uint32_t idx) {
// The `idx` has already been checked in `DexFileVerifier::CheckIntraClassDataItemMethods()`.
CHECK_LT(idx, header->method_ids_size_);
const dex::MethodId* method_id =
reinterpret_cast<const dex::MethodId*>(begin + header->method_ids_off_) + idx;
// Indexes in `*method_id` have already been checked in CheckIntraMethodIdItem().
std::string class_name = GetClass(begin, header, method_id->class_idx_);
std::string method_name = GetString(begin, header, method_id->name_idx_);
return class_name + "." + method_name;
}
} // namespace
// Note: the anonymous namespace would be nice, but we need friend access into accessors.
class DexFileVerifier {
public:
DexFileVerifier(const DexFile* dex_file,
const uint8_t* begin,
size_t size,
const char* location,
bool verify_checksum)
: dex_file_(dex_file),
begin_(begin),
size_(size),
location_(location),
verify_checksum_(verify_checksum),
header_(&dex_file->GetHeader()),
ptr_(nullptr),
previous_item_(nullptr),
init_indices_{std::numeric_limits<size_t>::max(),
std::numeric_limits<size_t>::max(),
std::numeric_limits<size_t>::max(),
std::numeric_limits<size_t>::max()} {
}
bool Verify();
const std::string& FailureReason() const {
return failure_reason_;
}
private:
bool CheckShortyDescriptorMatch(char shorty_char, const char* descriptor, bool is_return_type);
bool CheckListSize(const void* start, size_t count, size_t element_size, const char* label);
// Check a list. The head is assumed to be at *ptr, and elements to be of size element_size. If
// successful, the ptr will be moved forward the amount covered by the list.
bool CheckList(size_t element_size, const char* label, const uint8_t* *ptr);
// Checks whether the offset is zero (when size is zero) or that the offset falls within the area
// claimed by the file.
bool CheckValidOffsetAndSize(uint32_t offset, uint32_t size, size_t alignment, const char* label);
// Checks whether the size is less than the limit.
ALWAYS_INLINE bool 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;
}
ALWAYS_INLINE bool 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 CheckHeader();
bool CheckMap();
uint32_t 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 CheckAndGetHandlerOffsets(const dex::CodeItem* code_item,
uint32_t* handler_offsets, uint32_t handlers_size);
bool CheckClassDataItemField(uint32_t idx,
uint32_t access_flags,
uint32_t class_access_flags,
dex::TypeIndex class_type_index);
bool CheckClassDataItemMethod(uint32_t idx,
uint32_t access_flags,
uint32_t class_access_flags,
dex::TypeIndex class_type_index,
uint32_t code_offset,
bool expect_direct);
ALWAYS_INLINE
bool CheckOrder(const char* type_descr, uint32_t curr_index, uint32_t prev_index) {
if (UNLIKELY(curr_index < prev_index)) {
ErrorStringPrintf("out-of-order %s indexes %" PRIu32 " and %" PRIu32,
type_descr,
prev_index,
curr_index);
return false;
}
return true;
}
bool CheckStaticFieldTypes(const dex::ClassDef& class_def);
bool CheckPadding(size_t offset, uint32_t aligned_offset, DexFile::MapItemType type);
bool CheckEncodedValue();
bool CheckEncodedArray();
bool CheckEncodedAnnotation();
bool CheckIntraTypeIdItem();
bool CheckIntraProtoIdItem();
bool CheckIntraFieldIdItem();
bool CheckIntraMethodIdItem();
bool CheckIntraClassDefItem(uint32_t class_def_index);
bool CheckIntraMethodHandleItem();
bool CheckIntraTypeList();
// Check all fields of the given type, reading `encoded_field` entries from `ptr_`.
template <bool kStatic>
bool CheckIntraClassDataItemFields(size_t count);
// Check direct or virtual methods, reading `encoded_method` entries from `ptr_`.
// Check virtual methods against duplicates with direct methods.
bool CheckIntraClassDataItemMethods(size_t num_methods,
ClassAccessor::Method* direct_methods,
size_t num_direct_methods);
bool CheckIntraClassDataItem();
bool CheckIntraCodeItem();
bool CheckIntraStringDataItem();
bool CheckIntraDebugInfoItem();
bool CheckIntraAnnotationItem();
bool CheckIntraAnnotationsDirectoryItem();
bool CheckIntraHiddenapiClassData();
template <DexFile::MapItemType kType>
bool CheckIntraSectionIterate(size_t offset, uint32_t count);
template <DexFile::MapItemType kType>
bool CheckIntraIdSection(size_t offset, uint32_t count);
template <DexFile::MapItemType kType>
bool CheckIntraDataSection(size_t offset, uint32_t count);
bool CheckIntraSection();
bool CheckOffsetToTypeMap(size_t offset, uint16_t type);
// Returns kDexNoIndex if there are no fields/methods, otherwise a 16-bit type index.
uint32_t FindFirstClassDataDefiner(const ClassAccessor& accessor);
uint32_t FindFirstAnnotationsDirectoryDefiner(const uint8_t* ptr);
bool CheckInterStringIdItem();
bool CheckInterTypeIdItem();
bool CheckInterProtoIdItem();
bool CheckInterFieldIdItem();
bool CheckInterMethodIdItem();
bool CheckInterClassDefItem();
bool CheckInterCallSiteIdItem();
bool CheckInterAnnotationSetRefList();
bool CheckInterAnnotationSetItem();
bool CheckInterClassDataItem();
bool CheckInterAnnotationsDirectoryItem();
bool CheckInterSectionIterate(size_t offset, uint32_t count, DexFile::MapItemType type);
bool CheckInterSection();
void ErrorStringPrintf(const char* fmt, ...)
__attribute__((__format__(__printf__, 2, 3))) COLD_ATTR {
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);
}
bool FailureReasonIsSet() const { return failure_reason_.size() != 0; }
// Check validity of the given access flags, interpreted for a field in the context of a class
// with the given second access flags.
bool CheckFieldAccessFlags(uint32_t idx,
uint32_t field_access_flags,
uint32_t class_access_flags,
std::string* error_message);
// Check validity of the given method and access flags, in the context of a class with the given
// second access flags.
bool CheckMethodAccessFlags(uint32_t method_index,
uint32_t method_access_flags,
uint32_t class_access_flags,
uint32_t constructor_flags_by_name,
bool has_code,
bool expect_direct,
std::string* error_message);
// Check validity of given method if it's a constructor or class initializer.
bool CheckConstructorProperties(uint32_t method_index, uint32_t constructor_flags);
void FindStringRangesForMethodNames();
template <typename ExtraCheckFn>
bool VerifyTypeDescriptor(dex::TypeIndex idx, const char* error_msg, ExtraCheckFn extra_check);
const DexFile* const dex_file_;
const uint8_t* const begin_;
const size_t size_;
const char* const location_;
const bool verify_checksum_;
const DexFile::Header* const header_;
struct OffsetTypeMapEmptyFn {
// Make a hash map slot empty by making the offset 0. Offset 0 is a valid dex file offset that
// is in the offset of the dex file header. However, we only store data section items in the
// map, and these are after the header.
void MakeEmpty(std::pair<uint32_t, uint16_t>& pair) const {
pair.first = 0u;
}
// Check if a hash map slot is empty.
bool IsEmpty(const std::pair<uint32_t, uint16_t>& pair) const {
return pair.first == 0;
}
};
struct OffsetTypeMapHashCompareFn {
// Hash function for offset.
size_t operator()(const uint32_t key) const {
return key;
}
// std::equal function for offset.
bool operator()(const uint32_t a, const uint32_t b) const {
return a == b;
}
};
// Map from offset to dex file type, HashMap for performance reasons.
HashMap<uint32_t,
uint16_t,
OffsetTypeMapEmptyFn,
OffsetTypeMapHashCompareFn,
OffsetTypeMapHashCompareFn> offset_to_type_map_;
const uint8_t* ptr_;
const void* previous_item_;
std::string failure_reason_;
// Cached string indices for "interesting" entries wrt/ method names. Will be populated by
// FindStringRangesForMethodNames (which is automatically called before verifying the
// classdataitem section).
//
// Strings starting with '<' are in the range
// [angle_bracket_start_index_,angle_bracket_end_index_).
// angle_init_angle_index_ and angle_clinit_angle_index_ denote the indices of "<init>" and
// "<clinit>", respectively. If any value is not found, the corresponding index will be larger
// than any valid string index for this dex file.
struct {
size_t angle_bracket_start_index;
size_t angle_bracket_end_index;
size_t angle_init_angle_index;
size_t angle_clinit_angle_index;
} init_indices_;
// A bitvector for verified type descriptors. Each bit corresponds to a type index. A set
// bit denotes that the descriptor has been verified wrt/ IsValidDescriptor.
std::vector<char> verified_type_descriptors_;
// Set of type ids for which there are ClassDef elements in the dex file. Using a bitset
// avoids all allocations. The bitset should be implemented as 8K of storage, which is
// tight enough for all callers.
std::bitset<kTypeIdLimit + 1> defined_classes_;
// Class definition indexes, valid only if corresponding `defined_classes_[.]` is true.
std::vector<uint16_t> defined_class_indexes_;
};
template <typename ExtraCheckFn>
bool DexFileVerifier::VerifyTypeDescriptor(dex::TypeIndex idx,
const char* error_msg,
ExtraCheckFn extra_check) {
// All sources of the `idx` have already been checked in CheckIntraSection().
DCHECK_LT(idx.index_, header_->type_ids_size_);
auto err_fn = [&](const char* descriptor) {
ErrorStringPrintf("%s: '%s'", error_msg, descriptor);
};
char cached_char = verified_type_descriptors_[idx.index_];
if (cached_char != 0) {
if (!extra_check(cached_char)) {
const char* descriptor = dex_file_->StringByTypeIdx(idx);
err_fn(descriptor);
return false;
}
return true;
}
const char* descriptor = dex_file_->StringByTypeIdx(idx);
if (UNLIKELY(!IsValidDescriptor(descriptor))) {
err_fn(descriptor);
return false;
}
verified_type_descriptors_[idx.index_] = descriptor[0];
if (!extra_check(descriptor[0])) {
err_fn(descriptor);
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 element size is not 0.
DCHECK_NE(elem_size, 0U);
size_t offset = reinterpret_cast<const uint8_t*>(start) - begin_;
if (UNLIKELY(offset > size_)) {
ErrorStringPrintf("Offset beyond end of file for %s: %zx to %zx", label, offset, size_);
return false;
}
// Calculate the number of elements that fit until the end of file,
// rather than calculating the end of the range as that could overflow.
size_t max_elements = (size_ - offset) / elem_size;
if (UNLIKELY(max_elements < count)) {
ErrorStringPrintf(
"List too large for %s: %zx+%zu*%zu > %zx", label, offset, count, elem_size, size_);
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::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::CheckHeader() {
// Check file size from the header.
uint32_t expected_size = header_->file_size_;
if (size_ != expected_size) {
ErrorStringPrintf("Bad file size (%zd, expected %u)", size_, expected_size);
return false;
}
uint32_t adler_checksum = dex_file_->CalculateChecksum();
// Compute and verify the checksum in the header.
if (adler_checksum != header_->checksum_) {
if (verify_checksum_) {
ErrorStringPrintf("Bad checksum (%08x, expected %08x)", adler_checksum, header_->checksum_);
return false;
} else {
LOG(WARNING) << StringPrintf(
"Ignoring bad checksum (%08x, expected %08x)", adler_checksum, header_->checksum_);
}
}
// Check the contents of the header.
if (header_->endian_tag_ != DexFile::kDexEndianConstant) {
ErrorStringPrintf("Unexpected endian_tag: %x", header_->endian_tag_);
return false;
}
const uint32_t expected_header_size = dex_file_->IsCompactDexFile()
? sizeof(CompactDexFile::Header)
: sizeof(StandardDexFile::Header);
if (header_->header_size_ != expected_header_size) {
ErrorStringPrintf("Bad header size: %ud expected %ud",
header_->header_size_,
expected_header_size);
return false;
}
// Check that all offsets are inside the file.
bool result =
CheckValidOffsetAndSize(header_->link_off_,
header_->link_size_,
/* alignment= */ 0,
"link") &&
CheckValidOffsetAndSize(header_->map_off_,
header_->map_off_,
/* alignment= */ 4,
"map") &&
CheckValidOffsetAndSize(header_->string_ids_off_,
header_->string_ids_size_,
/* alignment= */ 4,
"string-ids") &&
CheckValidOffsetAndSize(header_->type_ids_off_,
header_->type_ids_size_,
/* alignment= */ 4,
"type-ids") &&
CheckSizeLimit(header_->type_ids_size_, DexFile::kDexNoIndex16, "type-ids") &&
CheckValidOffsetAndSize(header_->proto_ids_off_,
header_->proto_ids_size_,
/* alignment= */ 4,
"proto-ids") &&
CheckSizeLimit(header_->proto_ids_size_, DexFile::kDexNoIndex16, "proto-ids") &&
CheckValidOffsetAndSize(header_->field_ids_off_,
header_->field_ids_size_,
/* alignment= */ 4,
"field-ids") &&
CheckValidOffsetAndSize(header_->method_ids_off_,
header_->method_ids_size_,
/* alignment= */ 4,
"method-ids") &&
CheckValidOffsetAndSize(header_->class_defs_off_,
header_->class_defs_size_,
/* alignment= */ 4,
"class-defs") &&
CheckValidOffsetAndSize(header_->data_off_,
header_->data_size_,
// Unaligned, spec doesn't talk about it, even though size
// is supposed to be a multiple of 4.
/* alignment= */ 0,
"data");
return result;
}
bool DexFileVerifier::CheckMap() {
const dex::MapList* map = reinterpret_cast<const dex::MapList*>(begin_ + header_->map_off_);
// Check that map list content is available.
if (!CheckListSize(map, 1, sizeof(dex::MapList), "maplist content")) {
return false;
}
const dex::MapItem* item = map->list_;
uint32_t count = map->size_;
uint32_t last_offset = 0;
uint32_t last_type = 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(dex::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 for type %x last type was %x",
last_offset,
item->offset_,
static_cast<uint32_t>(item->type_),
last_type);
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;
}
DexFile::MapItemType item_type = static_cast<DexFile::MapItemType>(item->type_);
if (IsDataSectionType(item_type)) {
uint32_t icount = item->size_;
if (UNLIKELY(icount > data_items_left)) {
ErrorStringPrintf("Too many items in data section: %ud item_type %zx",
data_item_count + icount,
static_cast<size_t>(item_type));
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_;
last_type = item->type_;
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;
}
#define DECODE_UNSIGNED_CHECKED_FROM_WITH_ERROR_VALUE(ptr, var, error_value) \
uint32_t var; \
if (!DecodeUnsignedLeb128Checked(&(ptr), begin_ + size_, &(var))) { \
return error_value; \
}
#define DECODE_UNSIGNED_CHECKED_FROM(ptr, var) \
uint32_t var; \
if (!DecodeUnsignedLeb128Checked(&(ptr), begin_ + size_, &(var))) { \
ErrorStringPrintf("Read out of bounds"); \
return false; \
}
#define DECODE_SIGNED_CHECKED_FROM(ptr, var) \
int32_t var; \
if (!DecodeSignedLeb128Checked(&(ptr), begin_ + size_, &(var))) { \
ErrorStringPrintf("Read out of bounds"); \
return false; \
}
bool DexFileVerifier::CheckAndGetHandlerOffsets(const dex::CodeItem* code_item,
uint32_t* handler_offsets,
uint32_t handlers_size) {
CodeItemDataAccessor accessor(*dex_file_, code_item);
const uint8_t* handlers_base = accessor.GetCatchHandlerData();
for (uint32_t i = 0; i < handlers_size; i++) {
bool catch_all;
size_t offset = ptr_ - handlers_base;
DECODE_SIGNED_CHECKED_FROM(ptr_, size);
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) {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, type_idx);
if (!CheckIndex(type_idx, header_->type_ids_size_, "handler type_idx")) {
return false;
}
DECODE_UNSIGNED_CHECKED_FROM(ptr_, addr);
if (UNLIKELY(addr >= accessor.InsnsSizeInCodeUnits())) {
ErrorStringPrintf("Invalid handler addr: %x", addr);
return false;
}
}
if (catch_all) {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, addr);
if (UNLIKELY(addr >= accessor.InsnsSizeInCodeUnits())) {
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,
dex::TypeIndex class_type_index) {
// The `idx` has already been checked in `CheckIntraClassDataItemFields()`.
DCHECK_LE(idx, header_->field_ids_size_);
// Check that it's the right class.
dex::TypeIndex my_class_index =
(reinterpret_cast<const dex::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.index_,
class_type_index.index_);
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,
dex::TypeIndex class_type_index,
uint32_t code_offset,
bool expect_direct) {
// The `idx` has already been checked in `CheckIntraClassDataItemMethods()`.
DCHECK_LT(idx, header_->method_ids_size_);
const dex::MethodId& method_id =
*(reinterpret_cast<const dex::MethodId*>(begin_ + header_->method_ids_off_) + idx);
// Check that it's the right class.
dex::TypeIndex my_class_index = method_id.class_idx_;
if (class_type_index != my_class_index) {
ErrorStringPrintf("Method's class index unexpected, %" PRIu16 " vs %" PRIu16,
my_class_index.index_,
class_type_index.index_);
return false;
}
std::string error_msg;
uint32_t constructor_flags_by_name = 0;
{
uint32_t string_idx = method_id.name_idx_.index_;
if (!CheckIndex(string_idx, header_->string_ids_size_, "method flags verification")) {
return false;
}
if (UNLIKELY(string_idx < init_indices_.angle_bracket_end_index) &&
string_idx >= init_indices_.angle_bracket_start_index) {
if (string_idx == init_indices_.angle_clinit_angle_index) {
constructor_flags_by_name = kAccStatic | kAccConstructor;
} else if (string_idx == init_indices_.angle_init_angle_index) {
constructor_flags_by_name = kAccConstructor;
} else {
ErrorStringPrintf("Bad method name for method index %u", idx);
return false;
}
}
}
bool has_code = (code_offset != 0);
if (!CheckMethodAccessFlags(idx,
access_flags,
class_access_flags,
constructor_flags_by_name,
has_code,
expect_direct,
&error_msg)) {
ErrorStringPrintf("%s", error_msg.c_str());
return false;
}
if (constructor_flags_by_name != 0) {
if (!CheckConstructorProperties(idx, constructor_flags_by_name)) {
DCHECK(FailureReasonIsSet());
return false;
}
}
return true;
}
bool DexFileVerifier::CheckPadding(size_t offset,
uint32_t aligned_offset,
DexFile::MapItemType type) {
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 of type %zu at offset 0x%zx",
*ptr_,
static_cast<size_t>(type),
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;
case DexFile::kDexAnnotationMethodType: {
if (UNLIKELY(value_arg > 3)) {
ErrorStringPrintf("Bad encoded_value method type size %x", value_arg);
return false;
}
uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
if (!CheckIndex(idx, header_->proto_ids_size_, "method_type value")) {
return false;
}
break;
}
case DexFile::kDexAnnotationMethodHandle: {
if (UNLIKELY(value_arg > 3)) {
ErrorStringPrintf("Bad encoded_value method handle size %x", value_arg);
return false;
}
uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
if (!CheckIndex(idx, dex_file_->NumMethodHandles(), "method_handle value")) {
return false;
}
break;
}
default:
ErrorStringPrintf("Bogus encoded_value value_type %x", value_type);
return false;
}
return true;
}
bool DexFileVerifier::CheckEncodedArray() {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, size);
for (; size != 0u; --size) {
if (!CheckEncodedValue()) {
failure_reason_ = StringPrintf("Bad encoded_array value: %s", failure_reason_.c_str());
return false;
}
}
return true;
}
bool DexFileVerifier::CheckEncodedAnnotation() {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, anno_idx);
if (!CheckIndex(anno_idx, header_->type_ids_size_, "encoded_annotation type_idx")) {
return false;
}
DECODE_UNSIGNED_CHECKED_FROM(ptr_, size);
uint32_t last_idx = 0;
for (uint32_t i = 0; i < size; i++) {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, idx);
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::CheckStaticFieldTypes(const dex::ClassDef& class_def) {
ClassAccessor accessor(*dex_file_, ptr_);
EncodedStaticFieldValueIterator array_it(*dex_file_, class_def);
for (const ClassAccessor::Field& field : accessor.GetStaticFields()) {
if (!array_it.HasNext()) {
break;
}
uint32_t index = field.GetIndex();
// The `index` has already been checked in `CheckIntraClassDataItemFields()`.
DCHECK_LT(index, header_->field_ids_size_);
const dex::TypeId& type_id = dex_file_->GetTypeId(dex_file_->GetFieldId(index).type_idx_);
const char* field_type_name =
dex_file_->GetStringData(dex_file_->GetStringId(type_id.descriptor_idx_));
Primitive::Type field_type = Primitive::GetType(field_type_name[0]);
EncodedArrayValueIterator::ValueType array_type = array_it.GetValueType();
// Ensure this matches RuntimeEncodedStaticFieldValueIterator.
switch (array_type) {
case EncodedArrayValueIterator::ValueType::kBoolean:
if (field_type != Primitive::kPrimBoolean) {
ErrorStringPrintf("unexpected static field initial value type: 'Z' vs '%c'",
field_type_name[0]);
return false;
}
break;
case EncodedArrayValueIterator::ValueType::kByte:
if (field_type != Primitive::kPrimByte) {
ErrorStringPrintf("unexpected static field initial value type: 'B' vs '%c'",
field_type_name[0]);
return false;
}
break;
case EncodedArrayValueIterator::ValueType::kShort:
if (field_type != Primitive::kPrimShort) {
ErrorStringPrintf("unexpected static field initial value type: 'S' vs '%c'",
field_type_name[0]);
return false;
}
break;
case EncodedArrayValueIterator::ValueType::kChar:
if (field_type != Primitive::kPrimChar) {
ErrorStringPrintf("unexpected static field initial value type: 'C' vs '%c'",
field_type_name[0]);
return false;
}
break;
case EncodedArrayValueIterator::ValueType::kInt:
if (field_type != Primitive::kPrimInt) {
ErrorStringPrintf("unexpected static field initial value type: 'I' vs '%c'",
field_type_name[0]);
return false;
}
break;
case EncodedArrayValueIterator::ValueType::kLong:
if (field_type != Primitive::kPrimLong) {
ErrorStringPrintf("unexpected static field initial value type: 'J' vs '%c'",
field_type_name[0]);
return false;
}
break;
case EncodedArrayValueIterator::ValueType::kFloat:
if (field_type != Primitive::kPrimFloat) {
ErrorStringPrintf("unexpected static field initial value type: 'F' vs '%c'",
field_type_name[0]);
return false;
}
break;
case EncodedArrayValueIterator::ValueType::kDouble:
if (field_type != Primitive::kPrimDouble) {
ErrorStringPrintf("unexpected static field initial value type: 'D' vs '%c'",
field_type_name[0]);
return false;
}
break;
case EncodedArrayValueIterator::ValueType::kNull:
case EncodedArrayValueIterator::ValueType::kString:
case EncodedArrayValueIterator::ValueType::kType:
if (field_type != Primitive::kPrimNot) {
ErrorStringPrintf("unexpected static field initial value type: 'L' vs '%c'",
field_type_name[0]);
return false;
}
break;
default:
ErrorStringPrintf("unexpected static field initial value type: %x", array_type);
return false;
}
array_it.Next();
}
if (array_it.HasNext()) {
ErrorStringPrintf("too many static field initial values");
return false;
}
return true;
}
bool DexFileVerifier::CheckIntraTypeIdItem() {
if (!CheckListSize(ptr_, 1, sizeof(dex::TypeId), "type_ids")) {
return false;
}
const dex::TypeId* type_id = reinterpret_cast<const dex::TypeId*>(ptr_);
if (!CheckIndex(type_id->descriptor_idx_.index_,
header_->string_ids_size_,
"type_id.descriptor")) {
return false;
}
ptr_ += sizeof(dex::TypeId);
return true;
}
bool DexFileVerifier::CheckIntraProtoIdItem() {
if (!CheckListSize(ptr_, 1, sizeof(dex::ProtoId), "proto_ids")) {
return false;
}
const dex::ProtoId* proto_id = reinterpret_cast<const dex::ProtoId*>(ptr_);
if (!CheckIndex(proto_id->shorty_idx_.index_, header_->string_ids_size_, "proto_id.shorty") ||
!CheckIndex(proto_id->return_type_idx_.index_,
header_->type_ids_size_,
"proto_id.return_type")) {
return false;
}
ptr_ += sizeof(dex::ProtoId);
return true;
}
bool DexFileVerifier::CheckIntraFieldIdItem() {
if (!CheckListSize(ptr_, 1, sizeof(dex::FieldId), "field_ids")) {
return false;
}
const dex::FieldId* field_id = reinterpret_cast<const dex::FieldId*>(ptr_);
if (!CheckIndex(field_id->class_idx_.index_, header_->type_ids_size_, "field_id.class") ||
!CheckIndex(field_id->type_idx_.index_, header_->type_ids_size_, "field_id.type") ||
!CheckIndex(field_id->name_idx_.index_, header_->string_ids_size_, "field_id.name")) {
return false;
}
ptr_ += sizeof(dex::FieldId);
return true;
}
bool DexFileVerifier::CheckIntraMethodIdItem() {
if (!CheckListSize(ptr_, 1, sizeof(dex::MethodId), "method_ids")) {
return false;
}
const dex::MethodId* method_id = reinterpret_cast<const dex::MethodId*>(ptr_);
if (!CheckIndex(method_id->class_idx_.index_, header_->type_ids_size_, "method_id.class") ||
!CheckIndex(method_id->proto_idx_.index_, header_->proto_ids_size_, "method_id.proto") ||
!CheckIndex(method_id->name_idx_.index_, header_->string_ids_size_, "method_id.name")) {
return false;
}
ptr_ += sizeof(dex::MethodId);
return true;
}
bool DexFileVerifier::CheckIntraClassDefItem(uint32_t class_def_index) {
if (!CheckListSize(ptr_, 1, sizeof(dex::ClassDef), "class_defs")) {
return false;
}
const dex::ClassDef* class_def = reinterpret_cast<const dex::ClassDef*>(ptr_);
if (!CheckIndex(class_def->class_idx_.index_, header_->type_ids_size_, "class_def.class")) {
return false;
}
// Check superclass, if any.
if (UNLIKELY(class_def->pad2_ != 0u)) {
uint32_t combined =
(static_cast<uint32_t>(class_def->pad2_) << 16) + class_def->superclass_idx_.index_;
if (combined != 0xffffffffu) {
ErrorStringPrintf("Invalid superclass type padding/index: %x", combined);
return false;
}
} else if (!CheckIndex(class_def->superclass_idx_.index_,
header_->type_ids_size_,
"class_def.superclass")) {
return false;
}
DCHECK_LE(class_def->class_idx_.index_, kTypeIdLimit);
DCHECK_LT(kTypeIdLimit, defined_classes_.size());
if (defined_classes_[class_def->class_idx_.index_]) {
ErrorStringPrintf("Redefinition of class with type idx: '%u'", class_def->class_idx_.index_);
return false;
}
defined_classes_[class_def->class_idx_.index_] = true;
DCHECK_LE(class_def->class_idx_.index_, defined_class_indexes_.size());
defined_class_indexes_[class_def->class_idx_.index_] = class_def_index;
ptr_ += sizeof(dex::ClassDef);
return true;
}
bool DexFileVerifier::CheckIntraMethodHandleItem() {
if (!CheckListSize(ptr_, 1, sizeof(dex::MethodHandleItem), "method_handles")) {
return false;
}
const dex::MethodHandleItem* item = reinterpret_cast<const dex::MethodHandleItem*>(ptr_);
DexFile::MethodHandleType method_handle_type =
static_cast<DexFile::MethodHandleType>(item->method_handle_type_);
if (method_handle_type > DexFile::MethodHandleType::kLast) {
ErrorStringPrintf("Bad method handle type %x", item->method_handle_type_);
return false;
}
uint32_t index = item->field_or_method_idx_;
switch (method_handle_type) {
case DexFile::MethodHandleType::kStaticPut:
case DexFile::MethodHandleType::kStaticGet:
case DexFile::MethodHandleType::kInstancePut:
case DexFile::MethodHandleType::kInstanceGet:
if (!CheckIndex(index, header_->field_ids_size_, "method_handle_item field_idx")) {
return false;
}
break;
case DexFile::MethodHandleType::kInvokeStatic:
case DexFile::MethodHandleType::kInvokeInstance:
case DexFile::MethodHandleType::kInvokeConstructor:
case DexFile::MethodHandleType::kInvokeDirect:
case DexFile::MethodHandleType::kInvokeInterface: {
if (!CheckIndex(index, header_->method_ids_size_, "method_handle_item method_idx")) {
return false;
}
break;
}
}
ptr_ += sizeof(dex::MethodHandleItem);
return true;
}
bool DexFileVerifier::CheckIntraTypeList() {
const dex::TypeList* type_list = reinterpret_cast<const dex::TypeList*>(ptr_);
if (!CheckList(sizeof(dex::TypeItem), "type_list", &ptr_)) {
return false;
}
for (uint32_t i = 0, size = type_list->Size(); i != size; ++i) {
if (!CheckIndex(type_list->GetTypeItem(i).type_idx_.index_,
header_->type_ids_size_,
"type_list.type")) {
return false;
}
}
return true;
}
template <bool kStatic>
bool DexFileVerifier::CheckIntraClassDataItemFields(size_t count) {
constexpr const char* kTypeDescr = kStatic ? "static field" : "instance field";
// We cannot use ClassAccessor::Field yet as it could read beyond the end of the data section.
const uint8_t* ptr = ptr_;
const uint8_t* data_end = begin_ + header_->data_off_ + header_->data_size_;
uint32_t prev_index = 0;
for (size_t i = 0; i != count; ++i) {
uint32_t field_idx_diff, access_flags;
if (UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &field_idx_diff)) ||
UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &access_flags))) {
ErrorStringPrintf("encoded_field read out of bounds");
return false;
}
uint32_t curr_index = prev_index + field_idx_diff;
// Check for overflow.
if (!CheckIndex(curr_index, header_->field_ids_size_, "class_data_item field_idx")) {
return false;
}
if (!CheckOrder(kTypeDescr, curr_index, prev_index)) {
return false;
}
// Check that it falls into the right class-data list.
bool is_static = (access_flags & kAccStatic) != 0;
if (UNLIKELY(is_static != kStatic)) {
ErrorStringPrintf("Static/instance field not in expected list");
return false;
}
prev_index = curr_index;
}
ptr_ = ptr;
return true;
}
bool DexFileVerifier::CheckIntraClassDataItemMethods(size_t num_methods,
ClassAccessor::Method* direct_methods,
size_t num_direct_methods) {
DCHECK(num_direct_methods == 0u || direct_methods != nullptr);
const char* kTypeDescr = (direct_methods == nullptr) ? "direct method" : "virtual method";
// We cannot use ClassAccessor::Method yet as it could read beyond the end of the data section.
const uint8_t* ptr = ptr_;
const uint8_t* data_end = begin_ + header_->data_off_ + header_->data_size_;
// Load the first direct method for the check below.
size_t remaining_direct_methods = num_direct_methods;
if (remaining_direct_methods != 0u) {
DCHECK(direct_methods != nullptr);
direct_methods->Read();
}
uint32_t prev_index = 0;
for (size_t i = 0; i != num_methods; ++i) {
uint32_t method_idx_diff, access_flags, code_off;
if (UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &method_idx_diff)) ||
UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &access_flags)) ||
UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &code_off))) {
ErrorStringPrintf("encoded_method read out of bounds");
return false;
}
uint32_t curr_index = prev_index + method_idx_diff;
// Check for overflow.
if (!CheckIndex(curr_index, header_->method_ids_size_, "class_data_item method_idx")) {
return false;
}
if (!CheckOrder(kTypeDescr, curr_index, prev_index)) {
return false;
}
// For virtual methods, we cross reference the method index to make sure
// it doesn't match any direct methods.
if (remaining_direct_methods != 0) {
// The direct methods are already known to be in ascending index order.
// So just keep up with the current index.
while (true) {
const uint32_t direct_idx = direct_methods->GetIndex();
if (direct_idx > curr_index) {
break;
}
if (direct_idx == curr_index) {
ErrorStringPrintf("Found virtual method with same index as direct method: %u",
curr_index);
return false;
}
--remaining_direct_methods;
if (remaining_direct_methods == 0u) {
break;
}
direct_methods->Read();
}
}
prev_index = curr_index;
}
ptr_ = ptr;
return true;
}
bool DexFileVerifier::CheckIntraClassDataItem() {
// We cannot use ClassAccessor yet as it could read beyond the end of the data section.
const uint8_t* ptr = ptr_;
const uint8_t* data_end = begin_ + header_->data_off_ + header_->data_size_;
uint32_t static_fields_size, instance_fields_size, direct_methods_size, virtual_methods_size;
if (UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &static_fields_size)) ||
UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &instance_fields_size)) ||
UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &direct_methods_size)) ||
UNLIKELY(!DecodeUnsignedLeb128Checked(&ptr, data_end, &virtual_methods_size))) {
ErrorStringPrintf("class_data_item read out of bounds");
return false;
}
ptr_ = ptr;
// Check fields.
if (!CheckIntraClassDataItemFields</*kStatic=*/ true>(static_fields_size)) {
return false;
}
if (!CheckIntraClassDataItemFields</*kStatic=*/ false>(instance_fields_size)) {
return false;
}
// Check methods.
const uint8_t* direct_methods_ptr = ptr_;
if (!CheckIntraClassDataItemMethods(direct_methods_size,
/*direct_methods=*/ nullptr,
/*num_direct_methods=*/ 0u)) {
return false;
}
// Direct methods have been checked, so we can now use ClassAccessor::Method to read them again.
ClassAccessor::Method direct_methods(*dex_file_, direct_methods_ptr);
if (!CheckIntraClassDataItemMethods(virtual_methods_size, &direct_methods, direct_methods_size)) {
return false;
}
return true;
}
bool DexFileVerifier::CheckIntraCodeItem() {
const dex::CodeItem* code_item = reinterpret_cast<const dex::CodeItem*>(ptr_);
if (!CheckListSize(code_item, 1, sizeof(dex::CodeItem), "code")) {
return false;
}
CodeItemDataAccessor accessor(*dex_file_, code_item);
if (UNLIKELY(accessor.InsSize() > accessor.RegistersSize())) {
ErrorStringPrintf("ins_size (%ud) > registers_size (%ud)",
accessor.InsSize(), accessor.RegistersSize());
return false;
}
if (UNLIKELY(accessor.OutsSize() > 5 && accessor.OutsSize() > accessor.RegistersSize())) {
/*
* 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)",
accessor.OutsSize(), accessor.RegistersSize());
return false;
}
const uint16_t* insns = accessor.Insns();
uint32_t insns_size = accessor.InsnsSizeInCodeUnits();
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 = accessor.TriesSize();
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 dex::TryItem* try_items = accessor.TryItems().begin();
if (!CheckListSize(try_items, try_items_size, sizeof(dex::TryItem), "try_items size")) {
return false;
}
ptr_ = accessor.GetCatchHandlerData();
DECODE_UNSIGNED_CHECKED_FROM(ptr_, handlers_size);
if (UNLIKELY((handlers_size == 0) || (handlers_size >= 65536))) {
ErrorStringPrintf("Invalid handlers_size: %ud", handlers_size);
return false;
}
// Avoid an expensive allocation, if possible.
std::unique_ptr<uint32_t[]> handler_offsets_uptr;
uint32_t* handler_offsets;
constexpr size_t kAllocaMaxSize = 1024;
if (handlers_size < kAllocaMaxSize/sizeof(uint32_t)) {
// Note: Clang does not specify alignment guarantees for alloca. So align by hand.
handler_offsets =
AlignUp(reinterpret_cast<uint32_t*>(alloca((handlers_size + 1) * sizeof(uint32_t))),
alignof(uint32_t[]));
} else {
handler_offsets_uptr.reset(new uint32_t[handlers_size]);
handler_offsets = handler_offsets_uptr.get();
}
if (!CheckAndGetHandlerOffsets(code_item, &handler_offsets[0], handlers_size)) {
return false;
}
uint32_t last_addr = 0;
for (; try_items_size != 0u; --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() {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, size);
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() {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, dummy);
DECODE_UNSIGNED_CHECKED_FROM(ptr_, parameters_size);
if (UNLIKELY(parameters_size > 65536)) {
ErrorStringPrintf("Invalid parameters_size: %x", parameters_size);
return false;
}
for (uint32_t j = 0; j < parameters_size; j++) {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, parameter_name);
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: {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, advance_pc_dummy);
break;
}
case DexFile::DBG_ADVANCE_LINE: {
DECODE_SIGNED_CHECKED_FROM(ptr_, advance_line_dummy);
break;
}
case DexFile::DBG_START_LOCAL: {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, reg_num);
if (UNLIKELY(reg_num >= 65536)) {
ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
return false;
}
DECODE_UNSIGNED_CHECKED_FROM(ptr_, name_idx);
if (name_idx != 0) {
name_idx--;
if (!CheckIndex(name_idx, header_->string_ids_size_, "DBG_START_LOCAL name_idx")) {
return false;
}
}
DECODE_UNSIGNED_CHECKED_FROM(ptr_, type_idx);
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: {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, reg_num);
if (UNLIKELY(reg_num >= 65536)) {
ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
return false;
}
break;
}
case DexFile::DBG_START_LOCAL_EXTENDED: {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, reg_num);
if (UNLIKELY(reg_num >= 65536)) {
ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
return false;
}
DECODE_UNSIGNED_CHECKED_FROM(ptr_, name_idx);
if (name_idx != 0) {
name_idx--;
if (!CheckIndex(name_idx, header_->string_ids_size_, "DBG_START_LOCAL_EXTENDED name_idx")) {
return false;
}
}
DECODE_UNSIGNED_CHECKED_FROM(ptr_, type_idx);
if (type_idx != 0) {
type_idx--;
if (!CheckIndex(type_idx, header_->type_ids_size_, "DBG_START_LOCAL_EXTENDED type_idx")) {
return false;
}
}
DECODE_UNSIGNED_CHECKED_FROM(ptr_, sig_idx);
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: {
DECODE_UNSIGNED_CHECKED_FROM(ptr_, name_idx);
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::CheckIntraHiddenapiClassData() {
const dex::HiddenapiClassData* item = reinterpret_cast<const dex::HiddenapiClassData*>(ptr_);
// Check expected header size.
uint32_t num_header_elems = dex_file_->NumClassDefs() + 1;
uint32_t elem_size = sizeof(uint32_t);
uint32_t header_size = num_header_elems * elem_size;
if (!CheckListSize(item, num_header_elems, elem_size, "hiddenapi class data section header")) {
return false;
}
// Check total size.
if (!CheckListSize(item, item->size_, 1u, "hiddenapi class data section")) {
return false;
}
// Check that total size can fit header.
if (item->size_ < header_size) {
ErrorStringPrintf(
"Hiddenapi class data too short to store header (%u < %u)", item->size_, header_size);
return false;
}
const uint8_t* data_end = ptr_ + item->size_;
ptr_ += header_size;
// Check offsets for each class def.
for (uint32_t i = 0; i < dex_file_->NumClassDefs(); ++i) {
const dex::ClassDef& class_def = dex_file_->GetClassDef(i);
const uint8_t* class_data = dex_file_->GetClassData(class_def);
uint32_t offset = item->flags_offset_[i];
if (offset == 0) {
continue;
}
// Check that class defs with no class data do not have any hiddenapi class data.
if (class_data == nullptr) {
ErrorStringPrintf(
"Hiddenapi class data offset not zero for class def %u with no class data", i);
return false;
}
// Check that the offset is within the section.
if (offset > item->size_) {
ErrorStringPrintf(
"Hiddenapi class data offset out of section bounds (%u > %u) for class def %u",
offset, item->size_, i);
return false;
}
// Check that the offset matches current pointer position. We do not allow
// offsets into already parsed data, or gaps between class def data.
uint32_t ptr_offset = ptr_ - reinterpret_cast<const uint8_t*>(item);
if (offset != ptr_offset) {
ErrorStringPrintf(
"Hiddenapi class data unexpected offset (%u != %u) for class def %u",
offset, ptr_offset, i);
return false;
}
// Parse a uleb128 value for each field and method of this class.
bool failure = false;
auto fn_member = [&](const ClassAccessor::BaseItem& member, const char* member_type) {
if (failure) {
return;
}
uint32_t decoded_flags;
if (!DecodeUnsignedLeb128Checked(&ptr_, data_end, &decoded_flags)) {
ErrorStringPrintf("Hiddenapi class data value out of bounds (%p > %p) for %s %i",
ptr_, data_end, member_type, member.GetIndex());
failure = true;
return;
}
if (!hiddenapi::ApiList(decoded_flags).IsValid()) {
ErrorStringPrintf("Hiddenapi class data flags invalid (%u) for %s %i",
decoded_flags, member_type, member.GetIndex());
failure = true;
return;
}
};
auto fn_field = [&](const ClassAccessor::Field& field) { fn_member(field, "field"); };
auto fn_method = [&](const ClassAccessor::Method& method) { fn_member(method, "method"); };
ClassAccessor accessor(*dex_file_, class_data);
accessor.VisitFieldsAndMethods(fn_field, fn_field, fn_method, fn_method);
if (failure) {
return false;
}
}
if (ptr_ != data_end) {
ErrorStringPrintf("Hiddenapi class data wrong reported size (%u != %u)",
static_cast<uint32_t>(ptr_ - reinterpret_cast<const uint8_t*>(item)),
item->size_);
return false;
}
return true;
}
bool DexFileVerifier::CheckIntraAnnotationsDirectoryItem() {
const dex::AnnotationsDirectoryItem* item =
reinterpret_cast<const dex::AnnotationsDirectoryItem*>(ptr_);
if (!CheckListSize(item, 1, sizeof(dex::AnnotationsDirectoryItem), "annotations_directory")) {
return false;
}
// Field annotations follow immediately after the annotations directory.
const dex::FieldAnnotationsItem* field_item =
reinterpret_cast<const dex::FieldAnnotationsItem*>(item + 1);
uint32_t field_count = item->fields_size_;
if (!CheckListSize(field_item,
field_count,
sizeof(dex::FieldAnnotationsItem),
"field_annotations list")) {
return false;
}
uint32_t last_idx = 0;
for (uint32_t i = 0; i < field_count; i++) {
if (!CheckIndex(field_item->field_idx_, header_->field_ids_size_, "field annotation")) {
return false;
}
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 dex::MethodAnnotationsItem* method_item =
reinterpret_cast<const dex::MethodAnnotationsItem*>(field_item);
uint32_t method_count = item->methods_size_;
if (!CheckListSize(method_item,
method_count,
sizeof(dex::MethodAnnotationsItem),
"method_annotations list")) {
return false;
}
last_idx = 0;
for (uint32_t i = 0; i < method_count; i++) {
if (!CheckIndex(method_item->method_idx_, header_->method_ids_size_, "method annotation")) {
return false;
}
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 dex::ParameterAnnotationsItem* parameter_item =
reinterpret_cast<const dex::ParameterAnnotationsItem*>(method_item);
uint32_t parameter_count = item->parameters_size_;
if (!CheckListSize(parameter_item, parameter_count, sizeof(dex::ParameterAnnotationsItem),
"parameter_annotations list")) {
return false;
}
last_idx = 0;
for (uint32_t i = 0; i < parameter_count; i++) {
if (!CheckIndex(parameter_item->method_idx_,
header_->method_ids_size_,
"parameter annotation method")) {
return false;
}
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;
}
template <DexFile::MapItemType kType>
bool DexFileVerifier::CheckIntraSectionIterate(size_t offset, uint32_t section_count) {
// Get the right alignment mask for the type of section.
size_t alignment_mask;
switch (kType) {
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, kType)) {
return false;
}
// Check depending on the section type.
const uint8_t* start_ptr = ptr_;
switch (kType) {
case DexFile::kDexTypeStringIdItem: {
if (!CheckListSize(ptr_, 1, sizeof(dex::StringId), "string_ids")) {
return false;
}
ptr_ += sizeof(dex::StringId);
break;
}
case DexFile::kDexTypeTypeIdItem: {
if (!CheckIntraTypeIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeProtoIdItem: {
if (!CheckIntraProtoIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeFieldIdItem: {
if (!CheckIntraFieldIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeMethodIdItem: {
if (!CheckIntraMethodIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeClassDefItem: {
if (!CheckIntraClassDefItem(/*class_def_index=*/ i)) {
return false;
}
break;
}
case DexFile::kDexTypeCallSiteIdItem: {
if (!CheckListSize(ptr_, 1, sizeof(dex::CallSiteIdItem), "call_site_ids")) {
return false;
}
ptr_ += sizeof(dex::CallSiteIdItem);
break;
}
case DexFile::kDexTypeMethodHandleItem: {
if (!CheckIntraMethodHandleItem()) {
return false;
}
break;
}
case DexFile::kDexTypeTypeList: {
if (!CheckIntraTypeList()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationSetRefList: {
if (!CheckList(sizeof(dex::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;
}
case DexFile::kDexTypeHiddenapiClassData: {
if (!CheckIntraHiddenapiClassData()) {
return false;
}
break;
}
case DexFile::kDexTypeHeaderItem:
case DexFile::kDexTypeMapList:
break;
}
if (start_ptr == ptr_) {
ErrorStringPrintf("Unknown map item type %x", kType);
return false;
}
if (IsDataSectionType(kType)) {
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, kType));
}
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;
}
template <DexFile::MapItemType kType>
bool DexFileVerifier::CheckIntraIdSection(size_t offset, uint32_t count) {
uint32_t expected_offset;
uint32_t expected_size;
// Get the expected offset and size from the header.
switch (kType) {
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", kType);
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<kType>(offset, count);
}
template <DexFile::MapItemType kType>
bool DexFileVerifier::CheckIntraDataSection(size_t offset, uint32_t count) {
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<kType>(offset, count)) {
return false;
}
// FIXME: Doing this check late means we may have already read memory outside the
// data section and potentially outside the file, thus risking a segmentation fault.
size_t next_offset = ptr_ - begin_;
if (next_offset > data_end) {
ErrorStringPrintf("Out-of-bounds end of data subsection: %zu data_off=%u data_size=%u",
next_offset,
header_->data_off_,
header_->data_size_);
return false;
}
return true;
}
bool DexFileVerifier::CheckIntraSection() {
const dex::MapList* map = reinterpret_cast<const dex::MapList*>(begin_ + header_->map_off_);
const dex::MapItem* item = map->list_;
size_t offset = 0;
uint32_t count = map->size_;
ptr_ = begin_;
// Preallocate offset map to avoid some allocations. We can only guess from the list items,
// not derived things.
offset_to_type_map_.reserve(
std::min(header_->class_defs_size_, 65535u) +
std::min(header_->string_ids_size_, 65535u) +
2 * std::min(header_->method_ids_size_, 65535u));
// Check the items listed in the map.
for (; count != 0u; --count) {
const size_t current_offset = offset;
uint32_t section_offset = item->offset_;
uint32_t section_count = item->size_;
DexFile::MapItemType type = static_cast<DexFile::MapItemType>(item->type_);
// Check for padding and overlap between items.
if (!CheckPadding(offset, section_offset, type)) {
return false;
} else if (UNLIKELY(offset > section_offset)) {
ErrorStringPrintf("Section overlap or out-of-order map: %zx, %x", offset, section_offset);
return false;
}
if (type == DexFile::kDexTypeClassDataItem) {
FindStringRangesForMethodNames();
}
// 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;
#define CHECK_INTRA_ID_SECTION_CASE(type) \
case type: \
if (!CheckIntraIdSection<type>(section_offset, section_count)) { \
return false; \
} \
offset = ptr_ - begin_; \
break;
CHECK_INTRA_ID_SECTION_CASE(DexFile::kDexTypeStringIdItem)
CHECK_INTRA_ID_SECTION_CASE(DexFile::kDexTypeTypeIdItem)
CHECK_INTRA_ID_SECTION_CASE(DexFile::kDexTypeProtoIdItem)
CHECK_INTRA_ID_SECTION_CASE(DexFile::kDexTypeFieldIdItem)
CHECK_INTRA_ID_SECTION_CASE(DexFile::kDexTypeMethodIdItem)
CHECK_INTRA_ID_SECTION_CASE(DexFile::kDexTypeClassDefItem)
#undef CHECK_INTRA_ID_SECTION_CASE
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(dex::MapItem));
offset = section_offset + sizeof(uint32_t) + (map->size_ * sizeof(dex::MapItem));
break;
#define CHECK_INTRA_SECTION_ITERATE_CASE(type) \
case type: \
if (!CheckIntraSectionIterate<type>(section_offset, section_count)) { \
return false; \
} \
offset = ptr_ - begin_; \
break;
CHECK_INTRA_SECTION_ITERATE_CASE(DexFile::kDexTypeMethodHandleItem)
CHECK_INTRA_SECTION_ITERATE_CASE(DexFile::kDexTypeCallSiteIdItem)
#undef CHECK_INTRA_SECTION_ITERATE_CASE
#define CHECK_INTRA_DATA_SECTION_CASE(type) \
case type: \
if (!CheckIntraDataSection<type>(section_offset, section_count)) { \
return false; \
} \
offset = ptr_ - begin_; \
break;
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeTypeList)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeAnnotationSetRefList)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeAnnotationSetItem)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeClassDataItem)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeCodeItem)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeStringDataItem)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeDebugInfoItem)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeAnnotationItem)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeEncodedArrayItem)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeAnnotationsDirectoryItem)
CHECK_INTRA_DATA_SECTION_CASE(DexFile::kDexTypeHiddenapiClassData)
#undef CHECK_INTRA_DATA_SECTION_CASE
}
if (offset == current_offset) {
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;
}
uint32_t DexFileVerifier::FindFirstClassDataDefiner(const ClassAccessor& accessor) {
// The data item and field/method indexes have already been checked in
// `CheckIntraClassDataItem()` or its helper functions.
if (accessor.NumFields() != 0) {
ClassAccessor::Field read_field(*dex_file_, accessor.ptr_pos_);
read_field.Read();
DCHECK_LE(read_field.GetIndex(), dex_file_->NumFieldIds());
return dex_file_->GetFieldId(read_field.GetIndex()).class_idx_.index_;
}
if (accessor.NumMethods() != 0) {
ClassAccessor::Method read_method(*dex_file_, accessor.ptr_pos_);
read_method.Read();
DCHECK_LE(read_method.GetIndex(), dex_file_->NumMethodIds());
return dex_file_->GetMethodId(read_method.GetIndex()).class_idx_.index_;
}
return kDexNoIndex;
}
uint32_t DexFileVerifier::FindFirstAnnotationsDirectoryDefiner(const uint8_t* ptr) {
// The annotations directory and field/method indexes have already been checked in
// `CheckIntraAnnotationsDirectoryItem()`.
const dex::AnnotationsDirectoryItem* item =
reinterpret_cast<const dex::AnnotationsDirectoryItem*>(ptr);
if (item->fields_size_ != 0) {
dex::FieldAnnotationsItem* field_items = (dex::FieldAnnotationsItem*) (item + 1);
DCHECK_LE(field_items[0].field_idx_, dex_file_->NumFieldIds());
return dex_file_->GetFieldId(field_items[0].field_idx_).class_idx_.index_;
}
if (item->methods_size_ != 0) {
dex::MethodAnnotationsItem* method_items = (dex::MethodAnnotationsItem*) (item + 1);
DCHECK_LE(method_items[0].method_idx_, dex_file_->NumMethodIds());
return dex_file_->GetMethodId(method_items[0].method_idx_).class_idx_.index_;
}
if (item->parameters_size_ != 0) {
dex::ParameterAnnotationsItem* parameter_items = (dex::ParameterAnnotationsItem*) (item + 1);
DCHECK_LE(parameter_items[0].method_idx_, dex_file_->NumMethodIds());
return dex_file_->GetMethodId(parameter_items[0].method_idx_).class_idx_.index_;
}
return kDexNoIndex;
}
bool DexFileVerifier::CheckInterStringIdItem() {
const dex::StringId* item = reinterpret_cast<const dex::StringId*>(ptr_);
// Note: The mapping to string data items is eagerly verified at the start of CheckInterSection().
// Check ordering between items.
if (previous_item_ != nullptr) {
const dex::StringId* prev_item = reinterpret_cast<const dex::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(dex::StringId);
return true;
}
bool DexFileVerifier::CheckInterTypeIdItem() {
const dex::TypeId* item = reinterpret_cast<const dex::TypeId*>(ptr_);
{
// Translate to index to potentially use cache.
// The check in `CheckIntraIdSection()` guarantees that this index is valid.
size_t index = item - reinterpret_cast<const dex::TypeId*>(begin_ + header_->type_ids_off_);
DCHECK_LE(index, header_->type_ids_size_);
if (UNLIKELY(!VerifyTypeDescriptor(
dex::TypeIndex(static_cast<decltype(dex::TypeIndex::index_)>(index)),
"Invalid type descriptor",
[](char) { return true; }))) {
return false;
}
}
// Check ordering between items.
if (previous_item_ != nullptr) {
const dex::TypeId* prev_item = reinterpret_cast<const dex::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_.index_,
item->descriptor_idx_.index_);
return false;
}
}
ptr_ += sizeof(dex::TypeId);
return true;
}
bool DexFileVerifier::CheckInterProtoIdItem() {
const dex::ProtoId* item = reinterpret_cast<const dex::ProtoId*>(ptr_);
const char* shorty = dex_file_->StringDataByIdx(item->shorty_idx_);
if (item->parameters_off_ != 0 &&
!CheckOffsetToTypeMap(item->parameters_off_, DexFile::kDexTypeTypeList)) {
return false;
}
// Check that return type is representable as a uint16_t;
if (UNLIKELY(!IsValidOrNoTypeId(item->return_type_idx_.index_, item->pad_))) {
ErrorStringPrintf("proto with return type idx outside uint16_t range '%x:%x'",
item->pad_, item->return_type_idx_.index_);
return false;
}
// Check the return type and advance the shorty.
const char* return_type = dex_file_->StringByTypeIdx(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().index_,
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 dex::ProtoId* prev = reinterpret_cast<const dex::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()) {
dex::TypeIndex prev_idx = prev_it.GetTypeIdx();
dex::TypeIndex curr_idx = curr_it.GetTypeIdx();
DCHECK_NE(prev_idx, dex::TypeIndex(DexFile::kDexNoIndex16));
DCHECK_NE(curr_idx, dex::TypeIndex(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(dex::ProtoId);
return true;
}
bool DexFileVerifier::CheckInterFieldIdItem() {
const dex::FieldId* item = reinterpret_cast<const dex::FieldId*>(ptr_);
// Check that the class descriptor is valid.
if (UNLIKELY(!VerifyTypeDescriptor(item->class_idx_,
"Invalid descriptor for class_idx",
[](char d) { return d == 'L'; }))) {
return false;
}
// Check that the type descriptor is a valid field name.
if (UNLIKELY(!VerifyTypeDescriptor(item->type_idx_,
"Invalid descriptor for type_idx",
[](char d) { return d != 'V'; }))) {
return false;
}
// Check that the name is valid.
const char* field_name = dex_file_->StringDataByIdx(item->name_idx_);
if (UNLIKELY(!IsValidMemberName(field_name))) {
ErrorStringPrintf("Invalid field name: '%s'", field_name);
return false;
}
// Check ordering between items. This relies on the other sections being in order.
if (previous_item_ != nullptr) {
const dex::FieldId* prev_item = reinterpret_cast<const dex::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(dex::FieldId);
return true;
}
bool DexFileVerifier::CheckInterMethodIdItem() {
const dex::MethodId* item = reinterpret_cast<const dex::MethodId*>(ptr_);
// Check that the class descriptor is a valid reference name.
if (UNLIKELY(!VerifyTypeDescriptor(item->class_idx_,
"Invalid descriptor for class_idx",
[](char d) { return d == 'L' || d == '['; }))) {
return false;
}
// Check that the name is valid.
const char* method_name = dex_file_->StringDataByIdx(item->name_idx_);
if (UNLIKELY(!IsValidMemberName(method_name))) {
ErrorStringPrintf("Invalid method name: '%s'", method_name);
return false;
}
// Check that the proto id is valid.
if (UNLIKELY(!CheckIndex(item->proto_idx_.index_, 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 dex::MethodId* prev_item = reinterpret_cast<const dex::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(dex::MethodId);
return true;
}
bool DexFileVerifier::CheckInterClassDefItem() {
const dex::ClassDef* item = reinterpret_cast<const dex::ClassDef*>(ptr_);
// Check that class_idx_ is representable as a uint16_t;
if (UNLIKELY(!IsValidTypeId(item->class_idx_.index_, item->pad1_))) {
ErrorStringPrintf("class with type idx outside uint16_t range '%x:%x'", item->pad1_,
item->class_idx_.index_);
return false;
}
// Check that superclass_idx_ is representable as a uint16_t;
if (UNLIKELY(!IsValidOrNoTypeId(item->superclass_idx_.index_, item->pad2_))) {
ErrorStringPrintf("class with superclass type idx outside uint16_t range '%x:%x'", item->pad2_,
item->superclass_idx_.index_);
return false;
}
// Check for duplicate class def.
if (UNLIKELY(!VerifyTypeDescriptor(item->class_idx_,
"Invalid class descriptor",
[](char d) { return d == 'L'; }))) {
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_.IsValid()) {
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_.index_);
return false;
}
// Check that a class is defined after its super class (if the
// latter is defined in the same Dex file).
const dex::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_.index_,
item->superclass_idx_.index_);
return false;
}
}
}
if (UNLIKELY(!VerifyTypeDescriptor(item->superclass_idx_,
"Invalid superclass",
[](char d) { return d == 'L'; }))) {
return false;
}
}
// Check interfaces.
const dex::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_.index_);
return false;
}
// Check that a class is defined after the interfaces it implements
// (if they are defined in the same Dex file).
const dex::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_.index_,
interfaces->GetTypeItem(i).type_idx_.index_);
return false;
}
}
}
// Ensure that the interface refers to a class (not an array nor a primitive type).
if (UNLIKELY(!VerifyTypeDescriptor(interfaces->GetTypeItem(i).type_idx_,
"Invalid interface",
[](char d) { return d == 'L'; }))) {
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++) {
dex::TypeIndex idx1 = interfaces->GetTypeItem(i).type_idx_;
for (uint32_t j =0; j < i; j++) {
dex::TypeIndex 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) {
ClassAccessor accessor(*dex_file_, begin_ + item->class_data_off_);
uint32_t data_definer = FindFirstClassDataDefiner(accessor);
DCHECK(IsUint<16>(data_definer) || data_definer == kDexNoIndex) << data_definer;
if (UNLIKELY((data_definer != item->class_idx_.index_) && (data_definer != kDexNoIndex))) {
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_;
uint32_t defining_class = FindFirstAnnotationsDirectoryDefiner(data);
DCHECK(IsUint<16>(defining_class) || defining_class == kDexNoIndex) << defining_class;
if (UNLIKELY((defining_class != item->class_idx_.index_) && (defining_class != kDexNoIndex))) {
ErrorStringPrintf("Invalid annotations_directory_item");
return false;
}
}
ptr_ += sizeof(dex::ClassDef);
return true;
}
bool DexFileVerifier::CheckInterCallSiteIdItem() {
const dex::CallSiteIdItem* item = reinterpret_cast<const dex::CallSiteIdItem*>(ptr_);
// Check call site referenced by item is in encoded array section.
if (!CheckOffsetToTypeMap(item->data_off_, DexFile::kDexTypeEncodedArrayItem)) {
ErrorStringPrintf("Invalid offset in CallSideIdItem");
return false;
}
CallSiteArrayValueIterator it(*dex_file_, *item);
// Check Method Handle
if (!it.HasNext() || it.GetValueType() != EncodedArrayValueIterator::ValueType::kMethodHandle) {
ErrorStringPrintf("CallSiteArray missing method handle");
return false;
}
uint32_t handle_index = static_cast<uint32_t>(it.GetJavaValue().i);
if (handle_index >= dex_file_->NumMethodHandles()) {
ErrorStringPrintf("CallSite has bad method handle id: %x", handle_index);
return false;
}
// Check target method name.
it.Next();
if (!it.HasNext() ||
it.GetValueType() != EncodedArrayValueIterator::ValueType::kString) {
ErrorStringPrintf("CallSiteArray missing target method name");
return false;
}
uint32_t name_index = static_cast<uint32_t>(it.GetJavaValue().i);
if (name_index >= dex_file_->NumStringIds()) {
ErrorStringPrintf("CallSite has bad method name id: %x", name_index);
return false;
}
// Check method type.
it.Next();
if (!it.HasNext() ||
it.GetValueType() != EncodedArrayValueIterator::ValueType::kMethodType) {
ErrorStringPrintf("CallSiteArray missing method type");
return false;
}
uint32_t proto_index = static_cast<uint32_t>(it.GetJavaValue().i);
if (proto_index >= dex_file_->NumProtoIds()) {
ErrorStringPrintf("CallSite has bad method type: %x", proto_index);
return false;
}
ptr_ += sizeof(dex::CallSiteIdItem);
return true;
}
bool DexFileVerifier::CheckInterAnnotationSetRefList() {
const dex::AnnotationSetRefList* list = reinterpret_cast<const dex::AnnotationSetRefList*>(ptr_);
const dex::AnnotationSetRefItem* item = list->list_;
uint32_t count = list->size_;
for (; count != 0u; --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 dex::AnnotationSetItem* set = reinterpret_cast<const dex::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 dex::AnnotationItem* annotation =
reinterpret_cast<const dex::AnnotationItem*>(begin_ + *offsets);
const uint8_t* data = annotation->annotation_;
DECODE_UNSIGNED_CHECKED_FROM(data, idx);
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() {
ClassAccessor accessor(*dex_file_, ptr_);
uint32_t defining_class = FindFirstClassDataDefiner(accessor);
DCHECK(IsUint<16>(defining_class) || defining_class == kDexNoIndex) << defining_class;
if (defining_class == kDexNoIndex) {
return true; // Empty definitions are OK (but useless) and could be shared by multiple classes.
}
if (!defined_classes_[defining_class]) {
// Should really have a class definition for this class data item.
ErrorStringPrintf("Could not find declaring class for non-empty class data item.");
return false;
}
const dex::TypeIndex class_type_index(defining_class);
const dex::ClassDef& class_def = dex_file_->GetClassDef(defined_class_indexes_[defining_class]);
for (const ClassAccessor::Field& read_field : accessor.GetFields()) {
// The index has already been checked in `CheckIntraClassDataItemFields()`.
DCHECK_LE(read_field.GetIndex(), header_->field_ids_size_);
const dex::FieldId& field = dex_file_->GetFieldId(read_field.GetIndex());
if (UNLIKELY(field.class_idx_ != class_type_index)) {
ErrorStringPrintf("Mismatched defining class for class_data_item field");
return false;
}
if (!CheckClassDataItemField(read_field.GetIndex(),
read_field.GetAccessFlags(),
class_def.access_flags_,
class_type_index)) {
return false;
}
}
size_t num_direct_methods = accessor.NumDirectMethods();
size_t num_processed_methods = 0u;
auto methods = accessor.GetMethods();
auto it = methods.begin();
for (; it != methods.end(); ++it, ++num_processed_methods) {
uint32_t code_off = it->GetCodeItemOffset();
if (code_off != 0 && !CheckOffsetToTypeMap(code_off, DexFile::kDexTypeCodeItem)) {
return false;
}
// The index has already been checked in `CheckIntraClassDataItemMethods()`.
DCHECK_LE(it->GetIndex(), header_->method_ids_size_);
const dex::MethodId& method = dex_file_->GetMethodId(it->GetIndex());
if (UNLIKELY(method.class_idx_ != class_type_index)) {
ErrorStringPrintf("Mismatched defining class for class_data_item method");
return false;
}
bool expect_direct = num_processed_methods < num_direct_methods;
if (!CheckClassDataItemMethod(it->GetIndex(),
it->GetAccessFlags(),
class_def.access_flags_,
class_type_index,
it->GetCodeItemOffset(),
expect_direct)) {
return false;
}
}
// Check static field types against initial static values in encoded array.
if (!CheckStaticFieldTypes(class_def)) {
return false;
}
ptr_ = it.GetDataPointer();
return true;
}
bool DexFileVerifier::CheckInterAnnotationsDirectoryItem() {
const dex::AnnotationsDirectoryItem* item =
reinterpret_cast<const dex::AnnotationsDirectoryItem*>(ptr_);
uint32_t defining_class = FindFirstAnnotationsDirectoryDefiner(ptr_);
DCHECK(IsUint<16>(defining_class) || defining_class == kDexNoIndex) << defining_class;
if (item->class_annotations_off_ != 0 &&
!CheckOffsetToTypeMap(item->class_annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
return false;
}
// Field annotations follow immediately after the annotations directory.
const dex::FieldAnnotationsItem* field_item =
reinterpret_cast<const dex::FieldAnnotationsItem*>(item + 1);
uint32_t field_count = item->fields_size_;
for (uint32_t i = 0; i < field_count; i++) {
// The index has already been checked in `CheckIntraAnnotationsDirectoryItem()`.
DCHECK_LE(field_item->field_idx_, header_->field_ids_size_);
const dex::FieldId& field = dex_file_->GetFieldId(field_item->field_idx_);
if (UNLIKELY(field.class_idx_.index_ != 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 dex::MethodAnnotationsItem* method_item =
reinterpret_cast<const dex::MethodAnnotationsItem*>(field_item);
uint32_t method_count = item->methods_size_;
for (uint32_t i = 0; i < method_count; i++) {
// The index has already been checked in `CheckIntraAnnotationsDirectoryItem()`.
DCHECK_LE(method_item->method_idx_, header_->method_ids_size_);
const dex::MethodId& method = dex_file_->GetMethodId(method_item->method_idx_);
if (UNLIKELY(method.class_idx_.index_ != 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 dex::ParameterAnnotationsItem* parameter_item =
reinterpret_cast<const dex::ParameterAnnotationsItem*>(method_item);
uint32_t parameter_count = item->parameters_size_;
for (uint32_t i = 0; i < parameter_count; i++) {
// The index has already been checked in `CheckIntraAnnotationsDirectoryItem()`.
DCHECK_LE(parameter_item->method_idx_, header_->method_ids_size_);
const dex::MethodId& parameter_method = dex_file_->GetMethodId(parameter_item->method_idx_);
if (UNLIKELY(parameter_method.class_idx_.index_ != 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,
DexFile::MapItemType 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_;
if (MapTypeToBitMask(type) == 0) {
ErrorStringPrintf("Unknown map item type %x", type);
return false;
}
// Check depending on the section type.
switch (type) {
case DexFile::kDexTypeHeaderItem:
case DexFile::kDexTypeMethodHandleItem:
case DexFile::kDexTypeMapList:
case DexFile::kDexTypeTypeList:
case DexFile::kDexTypeCodeItem:
case DexFile::kDexTypeStringDataItem:
case DexFile::kDexTypeDebugInfoItem:
case DexFile::kDexTypeAnnotationItem:
case DexFile::kDexTypeEncodedArrayItem:
case DexFile::kDexTypeHiddenapiClassData:
break;
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: {
// There shouldn't be more class definitions than type ids allow.
// This is checked in `CheckIntraClassDefItem()` by checking the type
// index against `kTypeIdLimit` and rejecting dulicate definitions.
DCHECK_LE(i, kTypeIdLimit);
if (!CheckInterClassDefItem()) {
return false;
}
break;
}
case DexFile::kDexTypeCallSiteIdItem: {
if (!CheckInterCallSiteIdItem()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationSetRefList: {
if (!CheckInterAnnotationSetRefList()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationSetItem: {
if (!CheckInterAnnotationSetItem()) {
return false;
}
break;
}
case DexFile::kDexTypeClassDataItem: {
// There shouldn't be more class data than type ids allow.
// This check should be redundant, since there are checks that the
// class_idx_ is within range and that there is only one definition
// for a given type id.
if (i > kTypeIdLimit) {
ErrorStringPrintf("Too many class data items");
return false;
}
if (!CheckInterClassDataItem()) {
return false;
}
break;
}
case DexFile::kDexTypeAnnotationsDirectoryItem: {
if (!CheckInterAnnotationsDirectoryItem()) {
return false;
}
break;
}
}
previous_item_ = prev_ptr;
offset = ptr_ - begin_;
}
return true;
}
bool DexFileVerifier::CheckInterSection() {
// Eagerly verify that `StringId` offsets map to string data items to make sure
// we can retrieve the string data for verifying other items (types, shorties, etc.).
// After this we can safely use `DexFile` helpers such as `GetFieldId()` or `GetMethodId()`
// but not `PrettyMethod()` or `PrettyField()` as descriptors have not been verified yet.
const dex::StringId* string_ids =
reinterpret_cast<const dex::StringId*>(begin_ + header_->string_ids_off_);
for (size_t i = 0, num_strings = header_->string_ids_size_; i != num_strings; ++i) {
if (!CheckOffsetToTypeMap(string_ids[i].string_data_off_, DexFile::kDexTypeStringDataItem)) {
return false;
}
}
const dex::MapList* map = reinterpret_cast<const dex::MapList*>(begin_ + header_->map_off_);
const dex::MapItem* item = map->list_;
uint32_t count = map->size_;
// Cross check the items listed in the map.
for (; count != 0u; --count) {
uint32_t section_offset = item->offset_;
uint32_t section_count = item->size_;
DexFile::MapItemType type = static_cast<DexFile::MapItemType>(item->type_);
bool found = false;
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:
found = true;
break;
case DexFile::kDexTypeStringIdItem:
case DexFile::kDexTypeTypeIdItem:
case DexFile::kDexTypeProtoIdItem:
case DexFile::kDexTypeFieldIdItem:
case DexFile::kDexTypeMethodIdItem:
case DexFile::kDexTypeClassDefItem:
case DexFile::kDexTypeCallSiteIdItem:
case DexFile::kDexTypeMethodHandleItem:
case DexFile::kDexTypeAnnotationSetRefList:
case DexFile::kDexTypeAnnotationSetItem:
case DexFile::kDexTypeClassDataItem:
case DexFile::kDexTypeAnnotationsDirectoryItem:
case DexFile::kDexTypeHiddenapiClassData: {
if (!CheckInterSectionIterate(section_offset, section_count, type)) {
return false;
}
found = true;
break;
}
}
if (!found) {
ErrorStringPrintf("Unknown map item type %x", item->type_);
return false;
}
item++;
}
return true;
}
bool DexFileVerifier::Verify() {
// Check the header.
if (!CheckHeader()) {
return false;
}
// Check the map section.
if (!CheckMap()) {
return false;
}
DCHECK_LE(header_->type_ids_size_, kTypeIdLimit + 1u); // Checked in CheckHeader().
verified_type_descriptors_.resize(header_->type_ids_size_, 0);
defined_class_indexes_.resize(header_->type_ids_size_);
// Check structure within remaining sections.
if (!CheckIntraSection()) {
return false;
}
// Check references from one section to another.
if (!CheckInterSection()) {
return false;
}
return true;
}
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)",
GetFieldDescription(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)",
GetFieldDescription(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)",
GetFieldDescription(begin_, header_, idx).c_str(),
field_access_flags,
PrettyJavaAccessFlags(field_access_flags).c_str());
if (dex_file_->SupportsDefaultMethods()) {
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)",
GetFieldDescription(begin_, header_, idx).c_str(),
field_access_flags,
PrettyJavaAccessFlags(field_access_flags).c_str());
if (dex_file_->SupportsDefaultMethods()) {
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",
GetFieldDescription(begin_, header_, idx).c_str());
return false;
}
return true;
}
void DexFileVerifier::FindStringRangesForMethodNames() {
// Use DexFile::StringId* as RandomAccessIterator.
const dex::StringId* first = reinterpret_cast<const dex::StringId*>(
begin_ + header_->string_ids_off_);
const dex::StringId* last = first + header_->string_ids_size_;
auto get_string = [begin = begin_](const dex::StringId& id) {
const uint8_t* str_data_ptr = begin + id.string_data_off_;
DecodeUnsignedLeb128(&str_data_ptr);
return reinterpret_cast<const char*>(str_data_ptr);
};
auto compare = [&get_string](const dex::StringId& lhs, const char* rhs) {
return CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(get_string(lhs), rhs) < 0;
};
// '=' follows '<'
static_assert('<' + 1 == '=', "Unexpected character relation");
const auto angle_end = std::lower_bound(first, last, "=", compare);
init_indices_.angle_bracket_end_index = angle_end - first;
const auto angle_start = std::lower_bound(first, angle_end, "<", compare);
init_indices_.angle_bracket_start_index = angle_start - first;
if (angle_start == angle_end) {
// No strings starting with '<'.
init_indices_.angle_init_angle_index = std::numeric_limits<size_t>::max();
init_indices_.angle_clinit_angle_index = std::numeric_limits<size_t>::max();
return;
}
{
constexpr const char* kClinit = "<clinit>";
const auto it = std::lower_bound(angle_start, angle_end, kClinit, compare);
if (it != angle_end && strcmp(get_string(*it), kClinit) == 0) {
init_indices_.angle_clinit_angle_index = it - first;
} else {
init_indices_.angle_clinit_angle_index = std::numeric_limits<size_t>::max();
}
}
{
constexpr const char* kInit = "<init>";
const auto it = std::lower_bound(angle_start, angle_end, kInit, compare);
if (it != angle_end && strcmp(get_string(*it), kInit) == 0) {
init_indices_.angle_init_angle_index = it - first;
} else {
init_indices_.angle_init_angle_index = std::numeric_limits<size_t>::max();
}
}
}
bool DexFileVerifier::CheckMethodAccessFlags(uint32_t method_index,
uint32_t method_access_flags,
uint32_t class_access_flags,
uint32_t constructor_flags_by_name,
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",
GetMethodDescription(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",
GetMethodDescription(begin_, header_, method_index).c_str(),
method_access_flags);
return false;
}
constexpr uint32_t kConstructorFlags = kAccStatic | kAccConstructor;
const bool is_constructor_by_name = (constructor_flags_by_name & kConstructorFlags) != 0;
const bool is_clinit_by_name = constructor_flags_by_name == kConstructorFlags;
// 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_by_name) {
*error_msg =
StringPrintf("Method %" PRIu32 "(%s) is marked constructor, but doesn't match name",
method_index,
GetMethodDescription(begin_, header_, method_index).c_str());
return false;
}
if (is_constructor_by_name) {
// Check that the static constructor (= static initializer) is named "<clinit>" and that the
// instance constructor is called "<init>".
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,
GetMethodDescription(begin_, header_, method_index).c_str());
if (dex_file_->SupportsDefaultMethods()) {
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_by_name;
if (is_direct != expect_direct) {
*error_msg = StringPrintf("Direct/virtual method %" PRIu32 "(%s) not in expected list %d",
method_index,
GetMethodDescription(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_->SupportsDefaultMethods()) {
desired_flags |= kAccPrivate;
}
if ((method_access_flags & desired_flags) == 0) {
*error_msg = StringPrintf("Interface virtual method %" PRIu32 "(%s) is not public",
method_index,
GetMethodDescription(begin_, header_, method_index).c_str());
if (dex_file_->SupportsDefaultMethods()) {
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,
GetMethodDescription(begin_, header_, method_index).c_str());
return false;
}
// Constructors must always have code.
if (is_constructor_by_name) {
*error_msg = StringPrintf("Constructor %u(%s) must not be abstract or native",
method_index,
GetMethodDescription(begin_, header_, method_index).c_str());
if (dex_file_->SupportsDefaultMethods()) {
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,
GetMethodDescription(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 " << GetMethodDescription(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,
GetMethodDescription(begin_, header_, method_index).c_str());
if (dex_file_->SupportsDefaultMethods()) {
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,
GetMethodDescription(begin_, header_, method_index).c_str());
return false;
}
// Instance constructors must not be synchronized and a few other flags.
if (constructor_flags_by_name == kAccConstructor) {
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,
GetMethodDescription(begin_, header_, method_index).c_str(),
method_access_flags);
return false;
}
}
return true;
}
bool DexFileVerifier::CheckConstructorProperties(
uint32_t method_index,
uint32_t constructor_flags) {
DCHECK(constructor_flags == kAccConstructor ||
constructor_flags == (kAccConstructor | kAccStatic));
// Check signature matches expectations.
// The `method_index` has already been checked in `CheckIntraClassDataItemMethods()`.
CHECK_LT(method_index, header_->method_ids_size_);
const dex::MethodId& method_id = dex_file_->GetMethodId(method_index);
// The `method_id.proto_idx_` has already been checked in `CheckIntraMethodIdItem()`
DCHECK_LE(method_id.proto_idx_.index_, header_->proto_ids_size_);
Signature signature = dex_file_->GetMethodSignature(method_id);
if (constructor_flags == (kAccStatic | kAccConstructor)) {
if (!signature.IsVoid() || signature.GetNumberOfParameters() != 0) {
ErrorStringPrintf("<clinit> must have descriptor ()V");
return false;
}
} else if (!signature.IsVoid()) {
ErrorStringPrintf("Constructor %u(%s) must be void",
method_index,
GetMethodDescription(begin_, header_, method_index).c_str());
return false;
}
return true;
}
bool Verify(const DexFile* dex_file,
const uint8_t* begin,
size_t size,
const char* location,
bool verify_checksum,
std::string* error_msg) {
std::unique_ptr<DexFileVerifier> verifier(
new DexFileVerifier(dex_file, begin, size, location, verify_checksum));
if (!verifier->Verify()) {
*error_msg = verifier->FailureReason();
return false;
}
return true;
}
} // namespace dex
} // namespace art