dex_file_verifier.cc revision 78d639ef4be3ad7314846e1e6c1261d7d30f83fa
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "dex_file_verifier.h"
18
19#include <zlib.h>
20#include <memory>
21
22#include "base/stringprintf.h"
23#include "dex_file-inl.h"
24#include "leb128.h"
25#include "safe_map.h"
26#include "utf-inl.h"
27#include "utils.h"
28
29namespace art {
30
31static uint32_t MapTypeToBitMask(uint32_t map_type) {
32  switch (map_type) {
33    case DexFile::kDexTypeHeaderItem:               return 1 << 0;
34    case DexFile::kDexTypeStringIdItem:             return 1 << 1;
35    case DexFile::kDexTypeTypeIdItem:               return 1 << 2;
36    case DexFile::kDexTypeProtoIdItem:              return 1 << 3;
37    case DexFile::kDexTypeFieldIdItem:              return 1 << 4;
38    case DexFile::kDexTypeMethodIdItem:             return 1 << 5;
39    case DexFile::kDexTypeClassDefItem:             return 1 << 6;
40    case DexFile::kDexTypeMapList:                  return 1 << 7;
41    case DexFile::kDexTypeTypeList:                 return 1 << 8;
42    case DexFile::kDexTypeAnnotationSetRefList:     return 1 << 9;
43    case DexFile::kDexTypeAnnotationSetItem:        return 1 << 10;
44    case DexFile::kDexTypeClassDataItem:            return 1 << 11;
45    case DexFile::kDexTypeCodeItem:                 return 1 << 12;
46    case DexFile::kDexTypeStringDataItem:           return 1 << 13;
47    case DexFile::kDexTypeDebugInfoItem:            return 1 << 14;
48    case DexFile::kDexTypeAnnotationItem:           return 1 << 15;
49    case DexFile::kDexTypeEncodedArrayItem:         return 1 << 16;
50    case DexFile::kDexTypeAnnotationsDirectoryItem: return 1 << 17;
51  }
52  return 0;
53}
54
55static bool IsDataSectionType(uint32_t map_type) {
56  switch (map_type) {
57    case DexFile::kDexTypeHeaderItem:
58    case DexFile::kDexTypeStringIdItem:
59    case DexFile::kDexTypeTypeIdItem:
60    case DexFile::kDexTypeProtoIdItem:
61    case DexFile::kDexTypeFieldIdItem:
62    case DexFile::kDexTypeMethodIdItem:
63    case DexFile::kDexTypeClassDefItem:
64      return false;
65  }
66  return true;
67}
68
69const char* DexFileVerifier::CheckLoadStringByIdx(uint32_t idx, const char* error_string) {
70  if (UNLIKELY(!CheckIndex(idx, dex_file_->NumStringIds(), error_string))) {
71    return nullptr;
72  }
73  return dex_file_->StringDataByIdx(idx);
74}
75
76const char* DexFileVerifier::CheckLoadStringByTypeIdx(uint32_t type_idx, const char* error_string) {
77  if (UNLIKELY(!CheckIndex(type_idx, dex_file_->NumTypeIds(), error_string))) {
78    return nullptr;
79  }
80  const DexFile::TypeId& type_id = dex_file_->GetTypeId(type_idx);
81  uint32_t idx = type_id.descriptor_idx_;
82  return CheckLoadStringByIdx(idx, error_string);
83}
84
85const DexFile::FieldId* DexFileVerifier::CheckLoadFieldId(uint32_t idx, const char* error_string) {
86  if (UNLIKELY(!CheckIndex(idx, dex_file_->NumFieldIds(), error_string))) {
87    return nullptr;
88  }
89  return &dex_file_->GetFieldId(idx);
90}
91
92const DexFile::MethodId* DexFileVerifier::CheckLoadMethodId(uint32_t idx, const char* err_string) {
93  if (UNLIKELY(!CheckIndex(idx, dex_file_->NumMethodIds(), err_string))) {
94    return nullptr;
95  }
96  return &dex_file_->GetMethodId(idx);
97}
98
99// Helper macro to load string and return false on error.
100#define LOAD_STRING(var, idx, error)                  \
101  const char* var = CheckLoadStringByIdx(idx, error); \
102  if (UNLIKELY(var == nullptr)) {                     \
103    return false;                                     \
104  }
105
106// Helper macro to load string by type idx and return false on error.
107#define LOAD_STRING_BY_TYPE(var, type_idx, error)              \
108  const char* var = CheckLoadStringByTypeIdx(type_idx, error); \
109  if (UNLIKELY(var == nullptr)) {                              \
110    return false;                                              \
111  }
112
113// Helper macro to load method id. Return last parameter on error.
114#define LOAD_METHOD(var, idx, error_string, error_stmt)                 \
115  const DexFile::MethodId* var  = CheckLoadMethodId(idx, error_string); \
116  if (UNLIKELY(var == nullptr)) {                                       \
117    error_stmt;                                                         \
118  }
119
120// Helper macro to load method id. Return last parameter on error.
121#define LOAD_FIELD(var, idx, fmt, error_stmt)               \
122  const DexFile::FieldId* var = CheckLoadFieldId(idx, fmt); \
123  if (UNLIKELY(var == nullptr)) {                           \
124    error_stmt;                                             \
125  }
126
127bool DexFileVerifier::Verify(const DexFile* dex_file, const byte* begin, size_t size,
128                             const char* location, std::string* error_msg) {
129  std::unique_ptr<DexFileVerifier> verifier(new DexFileVerifier(dex_file, begin, size, location));
130  if (!verifier->Verify()) {
131    *error_msg = verifier->FailureReason();
132    return false;
133  }
134  return true;
135}
136
137bool DexFileVerifier::CheckShortyDescriptorMatch(char shorty_char, const char* descriptor,
138                                                bool is_return_type) {
139  switch (shorty_char) {
140    case 'V':
141      if (UNLIKELY(!is_return_type)) {
142        ErrorStringPrintf("Invalid use of void");
143        return false;
144      }
145      // Intentional fallthrough.
146    case 'B':
147    case 'C':
148    case 'D':
149    case 'F':
150    case 'I':
151    case 'J':
152    case 'S':
153    case 'Z':
154      if (UNLIKELY((descriptor[0] != shorty_char) || (descriptor[1] != '\0'))) {
155        ErrorStringPrintf("Shorty vs. primitive type mismatch: '%c', '%s'",
156                          shorty_char, descriptor);
157        return false;
158      }
159      break;
160    case 'L':
161      if (UNLIKELY((descriptor[0] != 'L') && (descriptor[0] != '['))) {
162        ErrorStringPrintf("Shorty vs. type mismatch: '%c', '%s'", shorty_char, descriptor);
163        return false;
164      }
165      break;
166    default:
167      ErrorStringPrintf("Bad shorty character: '%c'", shorty_char);
168      return false;
169  }
170  return true;
171}
172
173bool DexFileVerifier::CheckListSize(const void* start, size_t count, size_t elem_size,
174                                    const char* label) {
175  // Check that size is not 0.
176  CHECK_NE(elem_size, 0U);
177
178  const byte* range_start = reinterpret_cast<const byte*>(start);
179  const byte* file_start = reinterpret_cast<const byte*>(begin_);
180
181  // Check for overflow.
182  uintptr_t max = 0 - 1;
183  size_t available_bytes_till_end_of_mem = max - reinterpret_cast<uintptr_t>(start);
184  size_t max_count = available_bytes_till_end_of_mem / elem_size;
185  if (max_count < count) {
186    ErrorStringPrintf("Overflow in range for %s: %zx for %zu@%zu", label,
187                      static_cast<size_t>(range_start - file_start),
188                      count, elem_size);
189    return false;
190  }
191
192  const byte* range_end = range_start + count * elem_size;
193  const byte* file_end = file_start + size_;
194  if (UNLIKELY((range_start < file_start) || (range_end > file_end))) {
195    // Note: these two tests are enough as we make sure above that there's no overflow.
196    ErrorStringPrintf("Bad range for %s: %zx to %zx", label,
197                      static_cast<size_t>(range_start - file_start),
198                      static_cast<size_t>(range_end - file_start));
199    return false;
200  }
201  return true;
202}
203
204bool DexFileVerifier::CheckList(size_t element_size, const char* label, const byte* *ptr) {
205  // Check that the list is available. The first 4B are the count.
206  if (!CheckListSize(*ptr, 1, 4U, label)) {
207    return false;
208  }
209
210  uint32_t count = *reinterpret_cast<const uint32_t*>(*ptr);
211  if (count > 0) {
212    if (!CheckListSize(*ptr + 4, count, element_size, label)) {
213      return false;
214    }
215  }
216
217  *ptr += 4 + count * element_size;
218  return true;
219}
220
221bool DexFileVerifier::CheckIndex(uint32_t field, uint32_t limit, const char* label) {
222  if (UNLIKELY(field >= limit)) {
223    ErrorStringPrintf("Bad index for %s: %x >= %x", label, field, limit);
224    return false;
225  }
226  return true;
227}
228
229bool DexFileVerifier::CheckValidOffsetAndSize(uint32_t offset, uint32_t size, const char* label) {
230  if (size == 0) {
231    if (offset != 0) {
232      ErrorStringPrintf("Offset(%d) should be zero when size is zero for %s.", offset, label);
233      return false;
234    }
235  }
236  if (size_ <= offset) {
237    ErrorStringPrintf("Offset(%d) should be within file size(%zu) for %s.", offset, size_, label);
238    return false;
239  }
240  return true;
241}
242
243bool DexFileVerifier::CheckHeader() {
244  // Check file size from the header.
245  uint32_t expected_size = header_->file_size_;
246  if (size_ != expected_size) {
247    ErrorStringPrintf("Bad file size (%zd, expected %ud)", size_, expected_size);
248    return false;
249  }
250
251  // Compute and verify the checksum in the header.
252  uint32_t adler_checksum = adler32(0L, Z_NULL, 0);
253  const uint32_t non_sum = sizeof(header_->magic_) + sizeof(header_->checksum_);
254  const byte* non_sum_ptr = reinterpret_cast<const byte*>(header_) + non_sum;
255  adler_checksum = adler32(adler_checksum, non_sum_ptr, expected_size - non_sum);
256  if (adler_checksum != header_->checksum_) {
257    ErrorStringPrintf("Bad checksum (%08x, expected %08x)", adler_checksum, header_->checksum_);
258    return false;
259  }
260
261  // Check the contents of the header.
262  if (header_->endian_tag_ != DexFile::kDexEndianConstant) {
263    ErrorStringPrintf("Unexpected endian_tag: %x", header_->endian_tag_);
264    return false;
265  }
266
267  if (header_->header_size_ != sizeof(DexFile::Header)) {
268    ErrorStringPrintf("Bad header size: %ud", header_->header_size_);
269    return false;
270  }
271
272  // Check that all offsets are inside the file.
273  bool result =
274      CheckValidOffsetAndSize(header_->link_off_, header_->link_size_, "link") &&
275      CheckValidOffsetAndSize(header_->map_off_, header_->map_off_, "map") &&
276      CheckValidOffsetAndSize(header_->string_ids_off_, header_->string_ids_size_, "string-ids") &&
277      CheckValidOffsetAndSize(header_->type_ids_off_, header_->type_ids_size_, "type-ids") &&
278      CheckValidOffsetAndSize(header_->proto_ids_off_, header_->proto_ids_size_, "proto-ids") &&
279      CheckValidOffsetAndSize(header_->field_ids_off_, header_->field_ids_size_, "field-ids") &&
280      CheckValidOffsetAndSize(header_->method_ids_off_, header_->method_ids_size_, "method-ids") &&
281      CheckValidOffsetAndSize(header_->class_defs_off_, header_->class_defs_size_, "class-defs") &&
282      CheckValidOffsetAndSize(header_->data_off_, header_->data_size_, "data");
283
284  return result;
285}
286
287bool DexFileVerifier::CheckMap() {
288  const DexFile::MapList* map = reinterpret_cast<const DexFile::MapList*>(begin_ +
289                                                                          header_->map_off_);
290  // Check that map list content is available.
291  if (!CheckListSize(map, 1, sizeof(DexFile::MapList), "maplist content")) {
292    return false;
293  }
294
295  const DexFile::MapItem* item = map->list_;
296
297  uint32_t count = map->size_;
298  uint32_t last_offset = 0;
299  uint32_t data_item_count = 0;
300  uint32_t data_items_left = header_->data_size_;
301  uint32_t used_bits = 0;
302
303  // Sanity check the size of the map list.
304  if (!CheckListSize(item, count, sizeof(DexFile::MapItem), "map size")) {
305    return false;
306  }
307
308  // Check the items listed in the map.
309  for (uint32_t i = 0; i < count; i++) {
310    if (UNLIKELY(last_offset >= item->offset_ && i != 0)) {
311      ErrorStringPrintf("Out of order map item: %x then %x", last_offset, item->offset_);
312      return false;
313    }
314    if (UNLIKELY(item->offset_ >= header_->file_size_)) {
315      ErrorStringPrintf("Map item after end of file: %x, size %x",
316                        item->offset_, header_->file_size_);
317      return false;
318    }
319
320    if (IsDataSectionType(item->type_)) {
321      uint32_t icount = item->size_;
322      if (UNLIKELY(icount > data_items_left)) {
323        ErrorStringPrintf("Too many items in data section: %ud", data_item_count + icount);
324        return false;
325      }
326      data_items_left -= icount;
327      data_item_count += icount;
328    }
329
330    uint32_t bit = MapTypeToBitMask(item->type_);
331
332    if (UNLIKELY(bit == 0)) {
333      ErrorStringPrintf("Unknown map section type %x", item->type_);
334      return false;
335    }
336
337    if (UNLIKELY((used_bits & bit) != 0)) {
338      ErrorStringPrintf("Duplicate map section of type %x", item->type_);
339      return false;
340    }
341
342    used_bits |= bit;
343    last_offset = item->offset_;
344    item++;
345  }
346
347  // Check for missing sections in the map.
348  if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeHeaderItem)) == 0)) {
349    ErrorStringPrintf("Map is missing header entry");
350    return false;
351  }
352  if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeMapList)) == 0)) {
353    ErrorStringPrintf("Map is missing map_list entry");
354    return false;
355  }
356  if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeStringIdItem)) == 0 &&
357               ((header_->string_ids_off_ != 0) || (header_->string_ids_size_ != 0)))) {
358    ErrorStringPrintf("Map is missing string_ids entry");
359    return false;
360  }
361  if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeTypeIdItem)) == 0 &&
362               ((header_->type_ids_off_ != 0) || (header_->type_ids_size_ != 0)))) {
363    ErrorStringPrintf("Map is missing type_ids entry");
364    return false;
365  }
366  if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeProtoIdItem)) == 0 &&
367               ((header_->proto_ids_off_ != 0) || (header_->proto_ids_size_ != 0)))) {
368    ErrorStringPrintf("Map is missing proto_ids entry");
369    return false;
370  }
371  if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeFieldIdItem)) == 0 &&
372               ((header_->field_ids_off_ != 0) || (header_->field_ids_size_ != 0)))) {
373    ErrorStringPrintf("Map is missing field_ids entry");
374    return false;
375  }
376  if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeMethodIdItem)) == 0 &&
377               ((header_->method_ids_off_ != 0) || (header_->method_ids_size_ != 0)))) {
378    ErrorStringPrintf("Map is missing method_ids entry");
379    return false;
380  }
381  if (UNLIKELY((used_bits & MapTypeToBitMask(DexFile::kDexTypeClassDefItem)) == 0 &&
382               ((header_->class_defs_off_ != 0) || (header_->class_defs_size_ != 0)))) {
383    ErrorStringPrintf("Map is missing class_defs entry");
384    return false;
385  }
386  return true;
387}
388
389uint32_t DexFileVerifier::ReadUnsignedLittleEndian(uint32_t size) {
390  uint32_t result = 0;
391  if (LIKELY(CheckListSize(ptr_, size, sizeof(byte), "encoded_value"))) {
392    for (uint32_t i = 0; i < size; i++) {
393      result |= ((uint32_t) *(ptr_++)) << (i * 8);
394    }
395  }
396  return result;
397}
398
399bool DexFileVerifier::CheckAndGetHandlerOffsets(const DexFile::CodeItem* code_item,
400                                                uint32_t* handler_offsets, uint32_t handlers_size) {
401  const byte* handlers_base = DexFile::GetCatchHandlerData(*code_item, 0);
402
403  for (uint32_t i = 0; i < handlers_size; i++) {
404    bool catch_all;
405    size_t offset = ptr_ - handlers_base;
406    int32_t size = DecodeSignedLeb128(&ptr_);
407
408    if (UNLIKELY((size < -65536) || (size > 65536))) {
409      ErrorStringPrintf("Invalid exception handler size: %d", size);
410      return false;
411    }
412
413    if (size <= 0) {
414      catch_all = true;
415      size = -size;
416    } else {
417      catch_all = false;
418    }
419
420    handler_offsets[i] = static_cast<uint32_t>(offset);
421
422    while (size-- > 0) {
423      uint32_t type_idx = DecodeUnsignedLeb128(&ptr_);
424      if (!CheckIndex(type_idx, header_->type_ids_size_, "handler type_idx")) {
425        return false;
426      }
427
428      uint32_t addr = DecodeUnsignedLeb128(&ptr_);
429      if (UNLIKELY(addr >= code_item->insns_size_in_code_units_)) {
430        ErrorStringPrintf("Invalid handler addr: %x", addr);
431        return false;
432      }
433    }
434
435    if (catch_all) {
436      uint32_t addr = DecodeUnsignedLeb128(&ptr_);
437      if (UNLIKELY(addr >= code_item->insns_size_in_code_units_)) {
438        ErrorStringPrintf("Invalid handler catch_all_addr: %x", addr);
439        return false;
440      }
441    }
442  }
443
444  return true;
445}
446
447bool DexFileVerifier::CheckClassDataItemField(uint32_t idx, uint32_t access_flags,
448                                              bool expect_static) {
449  if (!CheckIndex(idx, header_->field_ids_size_, "class_data_item field_idx")) {
450    return false;
451  }
452
453  bool is_static = (access_flags & kAccStatic) != 0;
454  if (UNLIKELY(is_static != expect_static)) {
455    ErrorStringPrintf("Static/instance field not in expected list");
456    return false;
457  }
458
459  uint32_t access_field_mask = kAccPublic | kAccPrivate | kAccProtected | kAccStatic |
460      kAccFinal | kAccVolatile | kAccTransient | kAccSynthetic | kAccEnum;
461  if (UNLIKELY((access_flags & ~access_field_mask) != 0)) {
462    ErrorStringPrintf("Bad class_data_item field access_flags %x", access_flags);
463    return false;
464  }
465
466  return true;
467}
468
469bool DexFileVerifier::CheckClassDataItemMethod(uint32_t idx, uint32_t access_flags,
470                                               uint32_t code_offset, bool expect_direct) {
471  if (!CheckIndex(idx, header_->method_ids_size_, "class_data_item method_idx")) {
472    return false;
473  }
474
475  bool is_direct = (access_flags & (kAccStatic | kAccPrivate | kAccConstructor)) != 0;
476  bool expect_code = (access_flags & (kAccNative | kAccAbstract)) == 0;
477  bool is_synchronized = (access_flags & kAccSynchronized) != 0;
478  bool allow_synchronized = (access_flags & kAccNative) != 0;
479
480  if (UNLIKELY(is_direct != expect_direct)) {
481    ErrorStringPrintf("Direct/virtual method not in expected list");
482    return false;
483  }
484
485  uint32_t access_method_mask = kAccPublic | kAccPrivate | kAccProtected | kAccStatic |
486      kAccFinal | kAccSynchronized | kAccBridge | kAccVarargs | kAccNative | kAccAbstract |
487      kAccStrict | kAccSynthetic | kAccConstructor | kAccDeclaredSynchronized;
488  if (UNLIKELY(((access_flags & ~access_method_mask) != 0) ||
489               (is_synchronized && !allow_synchronized))) {
490    ErrorStringPrintf("Bad class_data_item method access_flags %x", access_flags);
491    return false;
492  }
493
494  if (UNLIKELY(expect_code && (code_offset == 0))) {
495    ErrorStringPrintf("Unexpected zero value for class_data_item method code_off with access "
496                      "flags %x", access_flags);
497    return false;
498  } else if (UNLIKELY(!expect_code && (code_offset != 0))) {
499    ErrorStringPrintf("Unexpected non-zero value %x for class_data_item method code_off"
500                      " with access flags %x", code_offset, access_flags);
501    return false;
502  }
503
504  return true;
505}
506
507bool DexFileVerifier::CheckPadding(size_t offset, uint32_t aligned_offset) {
508  if (offset < aligned_offset) {
509    if (!CheckListSize(begin_ + offset, aligned_offset - offset, sizeof(byte), "section")) {
510      return false;
511    }
512    while (offset < aligned_offset) {
513      if (UNLIKELY(*ptr_ != '\0')) {
514        ErrorStringPrintf("Non-zero padding %x before section start at %zx", *ptr_, offset);
515        return false;
516      }
517      ptr_++;
518      offset++;
519    }
520  }
521  return true;
522}
523
524bool DexFileVerifier::CheckEncodedValue() {
525  if (!CheckListSize(ptr_, 1, sizeof(byte), "encoded_value header")) {
526    return false;
527  }
528
529  uint8_t header_byte = *(ptr_++);
530  uint32_t value_type = header_byte & DexFile::kDexAnnotationValueTypeMask;
531  uint32_t value_arg = header_byte >> DexFile::kDexAnnotationValueArgShift;
532
533  switch (value_type) {
534    case DexFile::kDexAnnotationByte:
535      if (UNLIKELY(value_arg != 0)) {
536        ErrorStringPrintf("Bad encoded_value byte size %x", value_arg);
537        return false;
538      }
539      ptr_++;
540      break;
541    case DexFile::kDexAnnotationShort:
542    case DexFile::kDexAnnotationChar:
543      if (UNLIKELY(value_arg > 1)) {
544        ErrorStringPrintf("Bad encoded_value char/short size %x", value_arg);
545        return false;
546      }
547      ptr_ += value_arg + 1;
548      break;
549    case DexFile::kDexAnnotationInt:
550    case DexFile::kDexAnnotationFloat:
551      if (UNLIKELY(value_arg > 3)) {
552        ErrorStringPrintf("Bad encoded_value int/float size %x", value_arg);
553        return false;
554      }
555      ptr_ += value_arg + 1;
556      break;
557    case DexFile::kDexAnnotationLong:
558    case DexFile::kDexAnnotationDouble:
559      ptr_ += value_arg + 1;
560      break;
561    case DexFile::kDexAnnotationString: {
562      if (UNLIKELY(value_arg > 3)) {
563        ErrorStringPrintf("Bad encoded_value string size %x", value_arg);
564        return false;
565      }
566      uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
567      if (!CheckIndex(idx, header_->string_ids_size_, "encoded_value string")) {
568        return false;
569      }
570      break;
571    }
572    case DexFile::kDexAnnotationType: {
573      if (UNLIKELY(value_arg > 3)) {
574        ErrorStringPrintf("Bad encoded_value type size %x", value_arg);
575        return false;
576      }
577      uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
578      if (!CheckIndex(idx, header_->type_ids_size_, "encoded_value type")) {
579        return false;
580      }
581      break;
582    }
583    case DexFile::kDexAnnotationField:
584    case DexFile::kDexAnnotationEnum: {
585      if (UNLIKELY(value_arg > 3)) {
586        ErrorStringPrintf("Bad encoded_value field/enum size %x", value_arg);
587        return false;
588      }
589      uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
590      if (!CheckIndex(idx, header_->field_ids_size_, "encoded_value field")) {
591        return false;
592      }
593      break;
594    }
595    case DexFile::kDexAnnotationMethod: {
596      if (UNLIKELY(value_arg > 3)) {
597        ErrorStringPrintf("Bad encoded_value method size %x", value_arg);
598        return false;
599      }
600      uint32_t idx = ReadUnsignedLittleEndian(value_arg + 1);
601      if (!CheckIndex(idx, header_->method_ids_size_, "encoded_value method")) {
602        return false;
603      }
604      break;
605    }
606    case DexFile::kDexAnnotationArray:
607      if (UNLIKELY(value_arg != 0)) {
608        ErrorStringPrintf("Bad encoded_value array value_arg %x", value_arg);
609        return false;
610      }
611      if (!CheckEncodedArray()) {
612        return false;
613      }
614      break;
615    case DexFile::kDexAnnotationAnnotation:
616      if (UNLIKELY(value_arg != 0)) {
617        ErrorStringPrintf("Bad encoded_value annotation value_arg %x", value_arg);
618        return false;
619      }
620      if (!CheckEncodedAnnotation()) {
621        return false;
622      }
623      break;
624    case DexFile::kDexAnnotationNull:
625      if (UNLIKELY(value_arg != 0)) {
626        ErrorStringPrintf("Bad encoded_value null value_arg %x", value_arg);
627        return false;
628      }
629      break;
630    case DexFile::kDexAnnotationBoolean:
631      if (UNLIKELY(value_arg > 1)) {
632        ErrorStringPrintf("Bad encoded_value boolean size %x", value_arg);
633        return false;
634      }
635      break;
636    default:
637      ErrorStringPrintf("Bogus encoded_value value_type %x", value_type);
638      return false;
639  }
640
641  return true;
642}
643
644bool DexFileVerifier::CheckEncodedArray() {
645  uint32_t size = DecodeUnsignedLeb128(&ptr_);
646
647  while (size--) {
648    if (!CheckEncodedValue()) {
649      failure_reason_ = StringPrintf("Bad encoded_array value: %s", failure_reason_.c_str());
650      return false;
651    }
652  }
653  return true;
654}
655
656bool DexFileVerifier::CheckEncodedAnnotation() {
657  uint32_t idx = DecodeUnsignedLeb128(&ptr_);
658  if (!CheckIndex(idx, header_->type_ids_size_, "encoded_annotation type_idx")) {
659    return false;
660  }
661
662  uint32_t size = DecodeUnsignedLeb128(&ptr_);
663  uint32_t last_idx = 0;
664
665  for (uint32_t i = 0; i < size; i++) {
666    idx = DecodeUnsignedLeb128(&ptr_);
667    if (!CheckIndex(idx, header_->string_ids_size_, "annotation_element name_idx")) {
668      return false;
669    }
670
671    if (UNLIKELY(last_idx >= idx && i != 0)) {
672      ErrorStringPrintf("Out-of-order annotation_element name_idx: %x then %x",
673                        last_idx, idx);
674      return false;
675    }
676
677    if (!CheckEncodedValue()) {
678      return false;
679    }
680
681    last_idx = idx;
682  }
683  return true;
684}
685
686bool DexFileVerifier::CheckIntraClassDataItem() {
687  ClassDataItemIterator it(*dex_file_, ptr_);
688
689  for (; it.HasNextStaticField(); it.Next()) {
690    if (!CheckClassDataItemField(it.GetMemberIndex(), it.GetMemberAccessFlags(), true)) {
691      return false;
692    }
693  }
694  for (; it.HasNextInstanceField(); it.Next()) {
695    if (!CheckClassDataItemField(it.GetMemberIndex(), it.GetMemberAccessFlags(), false)) {
696      return false;
697    }
698  }
699  for (; it.HasNextDirectMethod(); it.Next()) {
700    if (!CheckClassDataItemMethod(it.GetMemberIndex(), it.GetMemberAccessFlags(),
701        it.GetMethodCodeItemOffset(), true)) {
702      return false;
703    }
704  }
705  for (; it.HasNextVirtualMethod(); it.Next()) {
706    if (!CheckClassDataItemMethod(it.GetMemberIndex(), it.GetMemberAccessFlags(),
707        it.GetMethodCodeItemOffset(), false)) {
708      return false;
709    }
710  }
711
712  ptr_ = it.EndDataPointer();
713  return true;
714}
715
716bool DexFileVerifier::CheckIntraCodeItem() {
717  const DexFile::CodeItem* code_item = reinterpret_cast<const DexFile::CodeItem*>(ptr_);
718  if (!CheckListSize(code_item, 1, sizeof(DexFile::CodeItem), "code")) {
719    return false;
720  }
721
722  if (UNLIKELY(code_item->ins_size_ > code_item->registers_size_)) {
723    ErrorStringPrintf("ins_size (%ud) > registers_size (%ud)",
724                      code_item->ins_size_, code_item->registers_size_);
725    return false;
726  }
727
728  if (UNLIKELY((code_item->outs_size_ > 5) &&
729               (code_item->outs_size_ > code_item->registers_size_))) {
730    /*
731     * outs_size can be up to 5, even if registers_size is smaller, since the
732     * short forms of method invocation allow repetitions of a register multiple
733     * times within a single parameter list. However, longer parameter lists
734     * need to be represented in-order in the register file.
735     */
736    ErrorStringPrintf("outs_size (%ud) > registers_size (%ud)",
737                      code_item->outs_size_, code_item->registers_size_);
738    return false;
739  }
740
741  const uint16_t* insns = code_item->insns_;
742  uint32_t insns_size = code_item->insns_size_in_code_units_;
743  if (!CheckListSize(insns, insns_size, sizeof(uint16_t), "insns size")) {
744    return false;
745  }
746
747  // Grab the end of the insns if there are no try_items.
748  uint32_t try_items_size = code_item->tries_size_;
749  if (try_items_size == 0) {
750    ptr_ = reinterpret_cast<const byte*>(&insns[insns_size]);
751    return true;
752  }
753
754  // try_items are 4-byte aligned. Verify the spacer is 0.
755  if (((reinterpret_cast<uintptr_t>(&insns[insns_size]) & 3) != 0) && (insns[insns_size] != 0)) {
756    ErrorStringPrintf("Non-zero padding: %x", insns[insns_size]);
757    return false;
758  }
759
760  const DexFile::TryItem* try_items = DexFile::GetTryItems(*code_item, 0);
761  ptr_ = DexFile::GetCatchHandlerData(*code_item, 0);
762  uint32_t handlers_size = DecodeUnsignedLeb128(&ptr_);
763
764  if (!CheckListSize(try_items, try_items_size, sizeof(DexFile::TryItem), "try_items size")) {
765    return false;
766  }
767
768  if (UNLIKELY((handlers_size == 0) || (handlers_size >= 65536))) {
769    ErrorStringPrintf("Invalid handlers_size: %ud", handlers_size);
770    return false;
771  }
772
773  std::unique_ptr<uint32_t[]> handler_offsets(new uint32_t[handlers_size]);
774  if (!CheckAndGetHandlerOffsets(code_item, &handler_offsets[0], handlers_size)) {
775    return false;
776  }
777
778  uint32_t last_addr = 0;
779  while (try_items_size--) {
780    if (UNLIKELY(try_items->start_addr_ < last_addr)) {
781      ErrorStringPrintf("Out-of_order try_item with start_addr: %x", try_items->start_addr_);
782      return false;
783    }
784
785    if (UNLIKELY(try_items->start_addr_ >= insns_size)) {
786      ErrorStringPrintf("Invalid try_item start_addr: %x", try_items->start_addr_);
787      return false;
788    }
789
790    uint32_t i;
791    for (i = 0; i < handlers_size; i++) {
792      if (try_items->handler_off_ == handler_offsets[i]) {
793        break;
794      }
795    }
796
797    if (UNLIKELY(i == handlers_size)) {
798      ErrorStringPrintf("Bogus handler offset: %x", try_items->handler_off_);
799      return false;
800    }
801
802    last_addr = try_items->start_addr_ + try_items->insn_count_;
803    if (UNLIKELY(last_addr > insns_size)) {
804      ErrorStringPrintf("Invalid try_item insn_count: %x", try_items->insn_count_);
805      return false;
806    }
807
808    try_items++;
809  }
810
811  return true;
812}
813
814bool DexFileVerifier::CheckIntraStringDataItem() {
815  uint32_t size = DecodeUnsignedLeb128(&ptr_);
816  const byte* file_end = begin_ + size_;
817
818  for (uint32_t i = 0; i < size; i++) {
819    CHECK_LT(i, size);  // b/15014252 Prevents hitting the impossible case below
820    if (UNLIKELY(ptr_ >= file_end)) {
821      ErrorStringPrintf("String data would go beyond end-of-file");
822      return false;
823    }
824
825    uint8_t byte = *(ptr_++);
826
827    // Switch on the high 4 bits.
828    switch (byte >> 4) {
829      case 0x00:
830        // Special case of bit pattern 0xxx.
831        if (UNLIKELY(byte == 0)) {
832          CHECK_LT(i, size);  // b/15014252 Actually hit this impossible case with clang
833          ErrorStringPrintf("String data shorter than indicated utf16_size %x", size);
834          return false;
835        }
836        break;
837      case 0x01:
838      case 0x02:
839      case 0x03:
840      case 0x04:
841      case 0x05:
842      case 0x06:
843      case 0x07:
844        // No extra checks necessary for bit pattern 0xxx.
845        break;
846      case 0x08:
847      case 0x09:
848      case 0x0a:
849      case 0x0b:
850      case 0x0f:
851        // Illegal bit patterns 10xx or 1111.
852        // Note: 1111 is valid for normal UTF-8, but not here.
853        ErrorStringPrintf("Illegal start byte %x in string data", byte);
854        return false;
855      case 0x0c:
856      case 0x0d: {
857        // Bit pattern 110x has an additional byte.
858        uint8_t byte2 = *(ptr_++);
859        if (UNLIKELY((byte2 & 0xc0) != 0x80)) {
860          ErrorStringPrintf("Illegal continuation byte %x in string data", byte2);
861          return false;
862        }
863        uint16_t value = ((byte & 0x1f) << 6) | (byte2 & 0x3f);
864        if (UNLIKELY((value != 0) && (value < 0x80))) {
865          ErrorStringPrintf("Illegal representation for value %x in string data", value);
866          return false;
867        }
868        break;
869      }
870      case 0x0e: {
871        // Bit pattern 1110 has 2 additional bytes.
872        uint8_t byte2 = *(ptr_++);
873        if (UNLIKELY((byte2 & 0xc0) != 0x80)) {
874          ErrorStringPrintf("Illegal continuation byte %x in string data", byte2);
875          return false;
876        }
877        uint8_t byte3 = *(ptr_++);
878        if (UNLIKELY((byte3 & 0xc0) != 0x80)) {
879          ErrorStringPrintf("Illegal continuation byte %x in string data", byte3);
880          return false;
881        }
882        uint16_t value = ((byte & 0x0f) << 12) | ((byte2 & 0x3f) << 6) | (byte3 & 0x3f);
883        if (UNLIKELY(value < 0x800)) {
884          ErrorStringPrintf("Illegal representation for value %x in string data", value);
885          return false;
886        }
887        break;
888      }
889    }
890  }
891
892  if (UNLIKELY(*(ptr_++) != '\0')) {
893    ErrorStringPrintf("String longer than indicated size %x", size);
894    return false;
895  }
896
897  return true;
898}
899
900bool DexFileVerifier::CheckIntraDebugInfoItem() {
901  DecodeUnsignedLeb128(&ptr_);
902  uint32_t parameters_size = DecodeUnsignedLeb128(&ptr_);
903  if (UNLIKELY(parameters_size > 65536)) {
904    ErrorStringPrintf("Invalid parameters_size: %x", parameters_size);
905    return false;
906  }
907
908  for (uint32_t j = 0; j < parameters_size; j++) {
909    uint32_t parameter_name = DecodeUnsignedLeb128(&ptr_);
910    if (parameter_name != 0) {
911      parameter_name--;
912      if (!CheckIndex(parameter_name, header_->string_ids_size_, "debug_info_item parameter_name")) {
913        return false;
914      }
915    }
916  }
917
918  while (true) {
919    uint8_t opcode = *(ptr_++);
920    switch (opcode) {
921      case DexFile::DBG_END_SEQUENCE: {
922        return true;
923      }
924      case DexFile::DBG_ADVANCE_PC: {
925        DecodeUnsignedLeb128(&ptr_);
926        break;
927      }
928      case DexFile::DBG_ADVANCE_LINE: {
929        DecodeSignedLeb128(&ptr_);
930        break;
931      }
932      case DexFile::DBG_START_LOCAL: {
933        uint32_t reg_num = DecodeUnsignedLeb128(&ptr_);
934        if (UNLIKELY(reg_num >= 65536)) {
935          ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
936          return false;
937        }
938        uint32_t name_idx = DecodeUnsignedLeb128(&ptr_);
939        if (name_idx != 0) {
940          name_idx--;
941          if (!CheckIndex(name_idx, header_->string_ids_size_, "DBG_START_LOCAL name_idx")) {
942            return false;
943          }
944        }
945        uint32_t type_idx = DecodeUnsignedLeb128(&ptr_);
946        if (type_idx != 0) {
947          type_idx--;
948          if (!CheckIndex(type_idx, header_->string_ids_size_, "DBG_START_LOCAL type_idx")) {
949            return false;
950          }
951        }
952        break;
953      }
954      case DexFile::DBG_END_LOCAL:
955      case DexFile::DBG_RESTART_LOCAL: {
956        uint32_t reg_num = DecodeUnsignedLeb128(&ptr_);
957        if (UNLIKELY(reg_num >= 65536)) {
958          ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
959          return false;
960        }
961        break;
962      }
963      case DexFile::DBG_START_LOCAL_EXTENDED: {
964        uint32_t reg_num = DecodeUnsignedLeb128(&ptr_);
965        if (UNLIKELY(reg_num >= 65536)) {
966          ErrorStringPrintf("Bad reg_num for opcode %x", opcode);
967          return false;
968        }
969        uint32_t name_idx = DecodeUnsignedLeb128(&ptr_);
970        if (name_idx != 0) {
971          name_idx--;
972          if (!CheckIndex(name_idx, header_->string_ids_size_, "DBG_START_LOCAL_EXTENDED name_idx")) {
973            return false;
974          }
975        }
976        uint32_t type_idx = DecodeUnsignedLeb128(&ptr_);
977        if (type_idx != 0) {
978          type_idx--;
979          if (!CheckIndex(type_idx, header_->string_ids_size_, "DBG_START_LOCAL_EXTENDED type_idx")) {
980            return false;
981          }
982        }
983        uint32_t sig_idx = DecodeUnsignedLeb128(&ptr_);
984        if (sig_idx != 0) {
985          sig_idx--;
986          if (!CheckIndex(sig_idx, header_->string_ids_size_, "DBG_START_LOCAL_EXTENDED sig_idx")) {
987            return false;
988          }
989        }
990        break;
991      }
992      case DexFile::DBG_SET_FILE: {
993        uint32_t name_idx = DecodeUnsignedLeb128(&ptr_);
994        if (name_idx != 0) {
995          name_idx--;
996          if (!CheckIndex(name_idx, header_->string_ids_size_, "DBG_SET_FILE name_idx")) {
997            return false;
998          }
999        }
1000        break;
1001      }
1002    }
1003  }
1004}
1005
1006bool DexFileVerifier::CheckIntraAnnotationItem() {
1007  if (!CheckListSize(ptr_, 1, sizeof(byte), "annotation visibility")) {
1008    return false;
1009  }
1010
1011  // Check visibility
1012  switch (*(ptr_++)) {
1013    case DexFile::kDexVisibilityBuild:
1014    case DexFile::kDexVisibilityRuntime:
1015    case DexFile::kDexVisibilitySystem:
1016      break;
1017    default:
1018      ErrorStringPrintf("Bad annotation visibility: %x", *ptr_);
1019      return false;
1020  }
1021
1022  if (!CheckEncodedAnnotation()) {
1023    return false;
1024  }
1025
1026  return true;
1027}
1028
1029bool DexFileVerifier::CheckIntraAnnotationsDirectoryItem() {
1030  const DexFile::AnnotationsDirectoryItem* item =
1031      reinterpret_cast<const DexFile::AnnotationsDirectoryItem*>(ptr_);
1032  if (!CheckListSize(item, 1, sizeof(DexFile::AnnotationsDirectoryItem), "annotations_directory")) {
1033    return false;
1034  }
1035
1036  // Field annotations follow immediately after the annotations directory.
1037  const DexFile::FieldAnnotationsItem* field_item =
1038      reinterpret_cast<const DexFile::FieldAnnotationsItem*>(item + 1);
1039  uint32_t field_count = item->fields_size_;
1040  if (!CheckListSize(field_item, field_count, sizeof(DexFile::FieldAnnotationsItem), "field_annotations list")) {
1041    return false;
1042  }
1043
1044  uint32_t last_idx = 0;
1045  for (uint32_t i = 0; i < field_count; i++) {
1046    if (UNLIKELY(last_idx >= field_item->field_idx_ && i != 0)) {
1047      ErrorStringPrintf("Out-of-order field_idx for annotation: %x then %x", last_idx, field_item->field_idx_);
1048      return false;
1049    }
1050    last_idx = field_item->field_idx_;
1051    field_item++;
1052  }
1053
1054  // Method annotations follow immediately after field annotations.
1055  const DexFile::MethodAnnotationsItem* method_item =
1056      reinterpret_cast<const DexFile::MethodAnnotationsItem*>(field_item);
1057  uint32_t method_count = item->methods_size_;
1058  if (!CheckListSize(method_item, method_count, sizeof(DexFile::MethodAnnotationsItem), "method_annotations list")) {
1059    return false;
1060  }
1061
1062  last_idx = 0;
1063  for (uint32_t i = 0; i < method_count; i++) {
1064    if (UNLIKELY(last_idx >= method_item->method_idx_ && i != 0)) {
1065      ErrorStringPrintf("Out-of-order method_idx for annotation: %x then %x",
1066                       last_idx, method_item->method_idx_);
1067      return false;
1068    }
1069    last_idx = method_item->method_idx_;
1070    method_item++;
1071  }
1072
1073  // Parameter annotations follow immediately after method annotations.
1074  const DexFile::ParameterAnnotationsItem* parameter_item =
1075      reinterpret_cast<const DexFile::ParameterAnnotationsItem*>(method_item);
1076  uint32_t parameter_count = item->parameters_size_;
1077  if (!CheckListSize(parameter_item, parameter_count, sizeof(DexFile::ParameterAnnotationsItem),
1078                     "parameter_annotations list")) {
1079    return false;
1080  }
1081
1082  last_idx = 0;
1083  for (uint32_t i = 0; i < parameter_count; i++) {
1084    if (UNLIKELY(last_idx >= parameter_item->method_idx_ && i != 0)) {
1085      ErrorStringPrintf("Out-of-order method_idx for annotation: %x then %x",
1086                        last_idx, parameter_item->method_idx_);
1087      return false;
1088    }
1089    last_idx = parameter_item->method_idx_;
1090    parameter_item++;
1091  }
1092
1093  // Return a pointer to the end of the annotations.
1094  ptr_ = reinterpret_cast<const byte*>(parameter_item);
1095  return true;
1096}
1097
1098bool DexFileVerifier::CheckIntraSectionIterate(size_t offset, uint32_t section_count,
1099                                               uint16_t type) {
1100  // Get the right alignment mask for the type of section.
1101  size_t alignment_mask;
1102  switch (type) {
1103    case DexFile::kDexTypeClassDataItem:
1104    case DexFile::kDexTypeStringDataItem:
1105    case DexFile::kDexTypeDebugInfoItem:
1106    case DexFile::kDexTypeAnnotationItem:
1107    case DexFile::kDexTypeEncodedArrayItem:
1108      alignment_mask = sizeof(uint8_t) - 1;
1109      break;
1110    default:
1111      alignment_mask = sizeof(uint32_t) - 1;
1112      break;
1113  }
1114
1115  // Iterate through the items in the section.
1116  for (uint32_t i = 0; i < section_count; i++) {
1117    size_t aligned_offset = (offset + alignment_mask) & ~alignment_mask;
1118
1119    // Check the padding between items.
1120    if (!CheckPadding(offset, aligned_offset)) {
1121      return false;
1122    }
1123
1124    // Check depending on the section type.
1125    switch (type) {
1126      case DexFile::kDexTypeStringIdItem: {
1127        if (!CheckListSize(ptr_, 1, sizeof(DexFile::StringId), "string_ids")) {
1128          return false;
1129        }
1130        ptr_ += sizeof(DexFile::StringId);
1131        break;
1132      }
1133      case DexFile::kDexTypeTypeIdItem: {
1134        if (!CheckListSize(ptr_, 1, sizeof(DexFile::TypeId), "type_ids")) {
1135          return false;
1136        }
1137        ptr_ += sizeof(DexFile::TypeId);
1138        break;
1139      }
1140      case DexFile::kDexTypeProtoIdItem: {
1141        if (!CheckListSize(ptr_, 1, sizeof(DexFile::ProtoId), "proto_ids")) {
1142          return false;
1143        }
1144        ptr_ += sizeof(DexFile::ProtoId);
1145        break;
1146      }
1147      case DexFile::kDexTypeFieldIdItem: {
1148        if (!CheckListSize(ptr_, 1, sizeof(DexFile::FieldId), "field_ids")) {
1149          return false;
1150        }
1151        ptr_ += sizeof(DexFile::FieldId);
1152        break;
1153      }
1154      case DexFile::kDexTypeMethodIdItem: {
1155        if (!CheckListSize(ptr_, 1, sizeof(DexFile::MethodId), "method_ids")) {
1156          return false;
1157        }
1158        ptr_ += sizeof(DexFile::MethodId);
1159        break;
1160      }
1161      case DexFile::kDexTypeClassDefItem: {
1162        if (!CheckListSize(ptr_, 1, sizeof(DexFile::ClassDef), "class_defs")) {
1163          return false;
1164        }
1165        ptr_ += sizeof(DexFile::ClassDef);
1166        break;
1167      }
1168      case DexFile::kDexTypeTypeList: {
1169        if (!CheckList(sizeof(DexFile::TypeItem), "type_list", &ptr_)) {
1170          return false;
1171        }
1172        break;
1173      }
1174      case DexFile::kDexTypeAnnotationSetRefList: {
1175        if (!CheckList(sizeof(DexFile::AnnotationSetRefItem), "annotation_set_ref_list", &ptr_)) {
1176          return false;
1177        }
1178        break;
1179      }
1180      case DexFile::kDexTypeAnnotationSetItem: {
1181        if (!CheckList(sizeof(uint32_t), "annotation_set_item", &ptr_)) {
1182          return false;
1183        }
1184        break;
1185      }
1186      case DexFile::kDexTypeClassDataItem: {
1187        if (!CheckIntraClassDataItem()) {
1188          return false;
1189        }
1190        break;
1191      }
1192      case DexFile::kDexTypeCodeItem: {
1193        if (!CheckIntraCodeItem()) {
1194          return false;
1195        }
1196        break;
1197      }
1198      case DexFile::kDexTypeStringDataItem: {
1199        if (!CheckIntraStringDataItem()) {
1200          return false;
1201        }
1202        break;
1203      }
1204      case DexFile::kDexTypeDebugInfoItem: {
1205        if (!CheckIntraDebugInfoItem()) {
1206          return false;
1207        }
1208        break;
1209      }
1210      case DexFile::kDexTypeAnnotationItem: {
1211        if (!CheckIntraAnnotationItem()) {
1212          return false;
1213        }
1214        break;
1215      }
1216      case DexFile::kDexTypeEncodedArrayItem: {
1217        if (!CheckEncodedArray()) {
1218          return false;
1219        }
1220        break;
1221      }
1222      case DexFile::kDexTypeAnnotationsDirectoryItem: {
1223        if (!CheckIntraAnnotationsDirectoryItem()) {
1224          return false;
1225        }
1226        break;
1227      }
1228      default:
1229        ErrorStringPrintf("Unknown map item type %x", type);
1230        return false;
1231    }
1232
1233    if (IsDataSectionType(type)) {
1234      offset_to_type_map_.Put(aligned_offset, type);
1235    }
1236
1237    aligned_offset = ptr_ - begin_;
1238    if (UNLIKELY(aligned_offset > size_)) {
1239      ErrorStringPrintf("Item %d at ends out of bounds", i);
1240      return false;
1241    }
1242
1243    offset = aligned_offset;
1244  }
1245
1246  return true;
1247}
1248
1249bool DexFileVerifier::CheckIntraIdSection(size_t offset, uint32_t count, uint16_t type) {
1250  uint32_t expected_offset;
1251  uint32_t expected_size;
1252
1253  // Get the expected offset and size from the header.
1254  switch (type) {
1255    case DexFile::kDexTypeStringIdItem:
1256      expected_offset = header_->string_ids_off_;
1257      expected_size = header_->string_ids_size_;
1258      break;
1259    case DexFile::kDexTypeTypeIdItem:
1260      expected_offset = header_->type_ids_off_;
1261      expected_size = header_->type_ids_size_;
1262      break;
1263    case DexFile::kDexTypeProtoIdItem:
1264      expected_offset = header_->proto_ids_off_;
1265      expected_size = header_->proto_ids_size_;
1266      break;
1267    case DexFile::kDexTypeFieldIdItem:
1268      expected_offset = header_->field_ids_off_;
1269      expected_size = header_->field_ids_size_;
1270      break;
1271    case DexFile::kDexTypeMethodIdItem:
1272      expected_offset = header_->method_ids_off_;
1273      expected_size = header_->method_ids_size_;
1274      break;
1275    case DexFile::kDexTypeClassDefItem:
1276      expected_offset = header_->class_defs_off_;
1277      expected_size = header_->class_defs_size_;
1278      break;
1279    default:
1280      ErrorStringPrintf("Bad type for id section: %x", type);
1281      return false;
1282  }
1283
1284  // Check that the offset and size are what were expected from the header.
1285  if (UNLIKELY(offset != expected_offset)) {
1286    ErrorStringPrintf("Bad offset for section: got %zx, expected %x", offset, expected_offset);
1287    return false;
1288  }
1289  if (UNLIKELY(count != expected_size)) {
1290    ErrorStringPrintf("Bad size for section: got %x, expected %x", count, expected_size);
1291    return false;
1292  }
1293
1294  return CheckIntraSectionIterate(offset, count, type);
1295}
1296
1297bool DexFileVerifier::CheckIntraDataSection(size_t offset, uint32_t count, uint16_t type) {
1298  size_t data_start = header_->data_off_;
1299  size_t data_end = data_start + header_->data_size_;
1300
1301  // Sanity check the offset of the section.
1302  if (UNLIKELY((offset < data_start) || (offset > data_end))) {
1303    ErrorStringPrintf("Bad offset for data subsection: %zx", offset);
1304    return false;
1305  }
1306
1307  if (!CheckIntraSectionIterate(offset, count, type)) {
1308    return false;
1309  }
1310
1311  size_t next_offset = ptr_ - begin_;
1312  if (next_offset > data_end) {
1313    ErrorStringPrintf("Out-of-bounds end of data subsection: %zx", next_offset);
1314    return false;
1315  }
1316
1317  return true;
1318}
1319
1320bool DexFileVerifier::CheckIntraSection() {
1321  const DexFile::MapList* map = reinterpret_cast<const DexFile::MapList*>(begin_ + header_->map_off_);
1322  const DexFile::MapItem* item = map->list_;
1323
1324  uint32_t count = map->size_;
1325  size_t offset = 0;
1326  ptr_ = begin_;
1327
1328  // Check the items listed in the map.
1329  while (count--) {
1330    uint32_t section_offset = item->offset_;
1331    uint32_t section_count = item->size_;
1332    uint16_t type = item->type_;
1333
1334    // Check for padding and overlap between items.
1335    if (!CheckPadding(offset, section_offset)) {
1336      return false;
1337    } else if (UNLIKELY(offset > section_offset)) {
1338      ErrorStringPrintf("Section overlap or out-of-order map: %zx, %x", offset, section_offset);
1339      return false;
1340    }
1341
1342    // Check each item based on its type.
1343    switch (type) {
1344      case DexFile::kDexTypeHeaderItem:
1345        if (UNLIKELY(section_count != 1)) {
1346          ErrorStringPrintf("Multiple header items");
1347          return false;
1348        }
1349        if (UNLIKELY(section_offset != 0)) {
1350          ErrorStringPrintf("Header at %x, not at start of file", section_offset);
1351          return false;
1352        }
1353        ptr_ = begin_ + header_->header_size_;
1354        offset = header_->header_size_;
1355        break;
1356      case DexFile::kDexTypeStringIdItem:
1357      case DexFile::kDexTypeTypeIdItem:
1358      case DexFile::kDexTypeProtoIdItem:
1359      case DexFile::kDexTypeFieldIdItem:
1360      case DexFile::kDexTypeMethodIdItem:
1361      case DexFile::kDexTypeClassDefItem:
1362        if (!CheckIntraIdSection(section_offset, section_count, type)) {
1363          return false;
1364        }
1365        offset = ptr_ - begin_;
1366        break;
1367      case DexFile::kDexTypeMapList:
1368        if (UNLIKELY(section_count != 1)) {
1369          ErrorStringPrintf("Multiple map list items");
1370          return false;
1371        }
1372        if (UNLIKELY(section_offset != header_->map_off_)) {
1373          ErrorStringPrintf("Map not at header-defined offset: %x, expected %x",
1374                            section_offset, header_->map_off_);
1375          return false;
1376        }
1377        ptr_ += sizeof(uint32_t) + (map->size_ * sizeof(DexFile::MapItem));
1378        offset = section_offset + sizeof(uint32_t) + (map->size_ * sizeof(DexFile::MapItem));
1379        break;
1380      case DexFile::kDexTypeTypeList:
1381      case DexFile::kDexTypeAnnotationSetRefList:
1382      case DexFile::kDexTypeAnnotationSetItem:
1383      case DexFile::kDexTypeClassDataItem:
1384      case DexFile::kDexTypeCodeItem:
1385      case DexFile::kDexTypeStringDataItem:
1386      case DexFile::kDexTypeDebugInfoItem:
1387      case DexFile::kDexTypeAnnotationItem:
1388      case DexFile::kDexTypeEncodedArrayItem:
1389      case DexFile::kDexTypeAnnotationsDirectoryItem:
1390        if (!CheckIntraDataSection(section_offset, section_count, type)) {
1391          return false;
1392        }
1393        offset = ptr_ - begin_;
1394        break;
1395      default:
1396        ErrorStringPrintf("Unknown map item type %x", type);
1397        return false;
1398    }
1399
1400    item++;
1401  }
1402
1403  return true;
1404}
1405
1406bool DexFileVerifier::CheckOffsetToTypeMap(size_t offset, uint16_t type) {
1407  auto it = offset_to_type_map_.find(offset);
1408  if (UNLIKELY(it == offset_to_type_map_.end())) {
1409    ErrorStringPrintf("No data map entry found @ %zx; expected %x", offset, type);
1410    return false;
1411  }
1412  if (UNLIKELY(it->second != type)) {
1413    ErrorStringPrintf("Unexpected data map entry @ %zx; expected %x, found %x",
1414                      offset, type, it->second);
1415    return false;
1416  }
1417  return true;
1418}
1419
1420uint16_t DexFileVerifier::FindFirstClassDataDefiner(const byte* ptr, bool* success) {
1421  ClassDataItemIterator it(*dex_file_, ptr);
1422  *success = true;
1423
1424  if (it.HasNextStaticField() || it.HasNextInstanceField()) {
1425    LOAD_FIELD(field, it.GetMemberIndex(), "first_class_data_definer field_id",
1426               *success = false; return DexFile::kDexNoIndex16)
1427    return field->class_idx_;
1428  }
1429
1430  if (it.HasNextDirectMethod() || it.HasNextVirtualMethod()) {
1431    LOAD_METHOD(method, it.GetMemberIndex(), "first_class_data_definer method_id",
1432                *success = false; return DexFile::kDexNoIndex16)
1433    return method->class_idx_;
1434  }
1435
1436  return DexFile::kDexNoIndex16;
1437}
1438
1439uint16_t DexFileVerifier::FindFirstAnnotationsDirectoryDefiner(const byte* ptr, bool* success) {
1440  const DexFile::AnnotationsDirectoryItem* item =
1441      reinterpret_cast<const DexFile::AnnotationsDirectoryItem*>(ptr);
1442  *success = true;
1443
1444  if (item->fields_size_ != 0) {
1445    DexFile::FieldAnnotationsItem* field_items = (DexFile::FieldAnnotationsItem*) (item + 1);
1446    LOAD_FIELD(field, field_items[0].field_idx_, "first_annotations_dir_definer field_id",
1447               *success = false; return DexFile::kDexNoIndex16)
1448    return field->class_idx_;
1449  }
1450
1451  if (item->methods_size_ != 0) {
1452    DexFile::MethodAnnotationsItem* method_items = (DexFile::MethodAnnotationsItem*) (item + 1);
1453    LOAD_METHOD(method, method_items[0].method_idx_, "first_annotations_dir_definer method id",
1454                *success = false; return DexFile::kDexNoIndex16)
1455    return method->class_idx_;
1456  }
1457
1458  if (item->parameters_size_ != 0) {
1459    DexFile::ParameterAnnotationsItem* parameter_items = (DexFile::ParameterAnnotationsItem*) (item + 1);
1460    LOAD_METHOD(method, parameter_items[0].method_idx_, "first_annotations_dir_definer method id",
1461                *success = false; return DexFile::kDexNoIndex16)
1462    return method->class_idx_;
1463  }
1464
1465  return DexFile::kDexNoIndex16;
1466}
1467
1468bool DexFileVerifier::CheckInterStringIdItem() {
1469  const DexFile::StringId* item = reinterpret_cast<const DexFile::StringId*>(ptr_);
1470
1471  // Check the map to make sure it has the right offset->type.
1472  if (!CheckOffsetToTypeMap(item->string_data_off_, DexFile::kDexTypeStringDataItem)) {
1473    return false;
1474  }
1475
1476  // Check ordering between items.
1477  if (previous_item_ != NULL) {
1478    const DexFile::StringId* prev_item = reinterpret_cast<const DexFile::StringId*>(previous_item_);
1479    const char* prev_str = dex_file_->GetStringData(*prev_item);
1480    const char* str = dex_file_->GetStringData(*item);
1481    if (UNLIKELY(CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(prev_str, str) >= 0)) {
1482      ErrorStringPrintf("Out-of-order string_ids: '%s' then '%s'", prev_str, str);
1483      return false;
1484    }
1485  }
1486
1487  ptr_ += sizeof(DexFile::StringId);
1488  return true;
1489}
1490
1491bool DexFileVerifier::CheckInterTypeIdItem() {
1492  const DexFile::TypeId* item = reinterpret_cast<const DexFile::TypeId*>(ptr_);
1493
1494  LOAD_STRING(descriptor, item->descriptor_idx_, "inter_type_id_item descriptor_idx")
1495
1496  // Check that the descriptor is a valid type.
1497  if (UNLIKELY(!IsValidDescriptor(descriptor))) {
1498    ErrorStringPrintf("Invalid type descriptor: '%s'", descriptor);
1499    return false;
1500  }
1501
1502  // Check ordering between items.
1503  if (previous_item_ != NULL) {
1504    const DexFile::TypeId* prev_item = reinterpret_cast<const DexFile::TypeId*>(previous_item_);
1505    if (UNLIKELY(prev_item->descriptor_idx_ >= item->descriptor_idx_)) {
1506      ErrorStringPrintf("Out-of-order type_ids: %x then %x",
1507                        prev_item->descriptor_idx_, item->descriptor_idx_);
1508      return false;
1509    }
1510  }
1511
1512  ptr_ += sizeof(DexFile::TypeId);
1513  return true;
1514}
1515
1516bool DexFileVerifier::CheckInterProtoIdItem() {
1517  const DexFile::ProtoId* item = reinterpret_cast<const DexFile::ProtoId*>(ptr_);
1518
1519  LOAD_STRING(shorty, item->shorty_idx_, "inter_proto_id_item shorty_idx")
1520
1521  if (item->parameters_off_ != 0 &&
1522      !CheckOffsetToTypeMap(item->parameters_off_, DexFile::kDexTypeTypeList)) {
1523    return false;
1524  }
1525
1526  // Check the return type and advance the shorty.
1527  LOAD_STRING_BY_TYPE(return_type, item->return_type_idx_, "inter_proto_id_item return_type_idx")
1528  if (!CheckShortyDescriptorMatch(*shorty, return_type, true)) {
1529    return false;
1530  }
1531  shorty++;
1532
1533  DexFileParameterIterator it(*dex_file_, *item);
1534  while (it.HasNext() && *shorty != '\0') {
1535    if (!CheckIndex(it.GetTypeIdx(), dex_file_->NumTypeIds(),
1536                    "inter_proto_id_item shorty type_idx")) {
1537      return false;
1538    }
1539    const char* descriptor = it.GetDescriptor();
1540    if (!CheckShortyDescriptorMatch(*shorty, descriptor, false)) {
1541      return false;
1542    }
1543    it.Next();
1544    shorty++;
1545  }
1546  if (UNLIKELY(it.HasNext() || *shorty != '\0')) {
1547    ErrorStringPrintf("Mismatched length for parameters and shorty");
1548    return false;
1549  }
1550
1551  // Check ordering between items. This relies on type_ids being in order.
1552  if (previous_item_ != NULL) {
1553    const DexFile::ProtoId* prev = reinterpret_cast<const DexFile::ProtoId*>(previous_item_);
1554    if (UNLIKELY(prev->return_type_idx_ > item->return_type_idx_)) {
1555      ErrorStringPrintf("Out-of-order proto_id return types");
1556      return false;
1557    } else if (prev->return_type_idx_ == item->return_type_idx_) {
1558      DexFileParameterIterator curr_it(*dex_file_, *item);
1559      DexFileParameterIterator prev_it(*dex_file_, *prev);
1560
1561      while (curr_it.HasNext() && prev_it.HasNext()) {
1562        uint16_t prev_idx = prev_it.GetTypeIdx();
1563        uint16_t curr_idx = curr_it.GetTypeIdx();
1564        if (prev_idx == DexFile::kDexNoIndex16) {
1565          break;
1566        }
1567        if (UNLIKELY(curr_idx == DexFile::kDexNoIndex16)) {
1568          ErrorStringPrintf("Out-of-order proto_id arguments");
1569          return false;
1570        }
1571
1572        if (prev_idx < curr_idx) {
1573          break;
1574        } else if (UNLIKELY(prev_idx > curr_idx)) {
1575          ErrorStringPrintf("Out-of-order proto_id arguments");
1576          return false;
1577        }
1578
1579        prev_it.Next();
1580        curr_it.Next();
1581      }
1582    }
1583  }
1584
1585  ptr_ += sizeof(DexFile::ProtoId);
1586  return true;
1587}
1588
1589bool DexFileVerifier::CheckInterFieldIdItem() {
1590  const DexFile::FieldId* item = reinterpret_cast<const DexFile::FieldId*>(ptr_);
1591
1592  // Check that the class descriptor is valid.
1593  LOAD_STRING_BY_TYPE(class_descriptor, item->class_idx_, "inter_field_id_item class_idx")
1594  if (UNLIKELY(!IsValidDescriptor(class_descriptor) || class_descriptor[0] != 'L')) {
1595    ErrorStringPrintf("Invalid descriptor for class_idx: '%s'", class_descriptor);
1596    return false;
1597  }
1598
1599  // Check that the type descriptor is a valid field name.
1600  LOAD_STRING_BY_TYPE(type_descriptor, item->type_idx_, "inter_field_id_item type_idx")
1601  if (UNLIKELY(!IsValidDescriptor(type_descriptor) || type_descriptor[0] == 'V')) {
1602    ErrorStringPrintf("Invalid descriptor for type_idx: '%s'", type_descriptor);
1603    return false;
1604  }
1605
1606  // Check that the name is valid.
1607  LOAD_STRING(descriptor, item->name_idx_, "inter_field_id_item name_idx")
1608  if (UNLIKELY(!IsValidMemberName(descriptor))) {
1609    ErrorStringPrintf("Invalid field name: '%s'", descriptor);
1610    return false;
1611  }
1612
1613  // Check ordering between items. This relies on the other sections being in order.
1614  if (previous_item_ != NULL) {
1615    const DexFile::FieldId* prev_item = reinterpret_cast<const DexFile::FieldId*>(previous_item_);
1616    if (UNLIKELY(prev_item->class_idx_ > item->class_idx_)) {
1617      ErrorStringPrintf("Out-of-order field_ids");
1618      return false;
1619    } else if (prev_item->class_idx_ == item->class_idx_) {
1620      if (UNLIKELY(prev_item->name_idx_ > item->name_idx_)) {
1621        ErrorStringPrintf("Out-of-order field_ids");
1622        return false;
1623      } else if (prev_item->name_idx_ == item->name_idx_) {
1624        if (UNLIKELY(prev_item->type_idx_ >= item->type_idx_)) {
1625          ErrorStringPrintf("Out-of-order field_ids");
1626          return false;
1627        }
1628      }
1629    }
1630  }
1631
1632  ptr_ += sizeof(DexFile::FieldId);
1633  return true;
1634}
1635
1636bool DexFileVerifier::CheckInterMethodIdItem() {
1637  const DexFile::MethodId* item = reinterpret_cast<const DexFile::MethodId*>(ptr_);
1638
1639  // Check that the class descriptor is a valid reference name.
1640  LOAD_STRING_BY_TYPE(class_descriptor, item->class_idx_, "inter_method_id_item class_idx")
1641  if (UNLIKELY(!IsValidDescriptor(class_descriptor) || (class_descriptor[0] != 'L' &&
1642                                                        class_descriptor[0] != '['))) {
1643    ErrorStringPrintf("Invalid descriptor for class_idx: '%s'", class_descriptor);
1644    return false;
1645  }
1646
1647  // Check that the name is valid.
1648  LOAD_STRING(descriptor, item->name_idx_, "inter_method_id_item name_idx")
1649  if (UNLIKELY(!IsValidMemberName(descriptor))) {
1650    ErrorStringPrintf("Invalid method name: '%s'", descriptor);
1651    return false;
1652  }
1653
1654  // Check that the proto id is valid.
1655  if (UNLIKELY(!CheckIndex(item->proto_idx_, dex_file_->NumProtoIds(),
1656                           "inter_method_id_item proto_idx"))) {
1657    return false;
1658  }
1659
1660  // Check ordering between items. This relies on the other sections being in order.
1661  if (previous_item_ != NULL) {
1662    const DexFile::MethodId* prev_item = reinterpret_cast<const DexFile::MethodId*>(previous_item_);
1663    if (UNLIKELY(prev_item->class_idx_ > item->class_idx_)) {
1664      ErrorStringPrintf("Out-of-order method_ids");
1665      return false;
1666    } else if (prev_item->class_idx_ == item->class_idx_) {
1667      if (UNLIKELY(prev_item->name_idx_ > item->name_idx_)) {
1668        ErrorStringPrintf("Out-of-order method_ids");
1669        return false;
1670      } else if (prev_item->name_idx_ == item->name_idx_) {
1671        if (UNLIKELY(prev_item->proto_idx_ >= item->proto_idx_)) {
1672          ErrorStringPrintf("Out-of-order method_ids");
1673          return false;
1674        }
1675      }
1676    }
1677  }
1678
1679  ptr_ += sizeof(DexFile::MethodId);
1680  return true;
1681}
1682
1683bool DexFileVerifier::CheckInterClassDefItem() {
1684  const DexFile::ClassDef* item = reinterpret_cast<const DexFile::ClassDef*>(ptr_);
1685
1686  // Check for duplicate class def.
1687  if (defined_classes_.find(item->class_idx_) != defined_classes_.end()) {
1688    ErrorStringPrintf("Redefinition of class with type idx: '%d'", item->class_idx_);
1689    return false;
1690  }
1691  defined_classes_.insert(item->class_idx_);
1692
1693  LOAD_STRING_BY_TYPE(class_descriptor, item->class_idx_, "inter_class_def_item class_idx")
1694  if (UNLIKELY(!IsValidDescriptor(class_descriptor) || class_descriptor[0] != 'L')) {
1695    ErrorStringPrintf("Invalid class descriptor: '%s'", class_descriptor);
1696    return false;
1697  }
1698
1699  // Only allow non-runtime modifiers.
1700  if ((item->access_flags_ & ~kAccJavaFlagsMask) != 0) {
1701    ErrorStringPrintf("Invalid class flags: '%d'", item->access_flags_);
1702    return false;
1703  }
1704
1705  if (item->interfaces_off_ != 0 &&
1706      !CheckOffsetToTypeMap(item->interfaces_off_, DexFile::kDexTypeTypeList)) {
1707    return false;
1708  }
1709  if (item->annotations_off_ != 0 &&
1710      !CheckOffsetToTypeMap(item->annotations_off_, DexFile::kDexTypeAnnotationsDirectoryItem)) {
1711    return false;
1712  }
1713  if (item->class_data_off_ != 0 &&
1714      !CheckOffsetToTypeMap(item->class_data_off_, DexFile::kDexTypeClassDataItem)) {
1715    return false;
1716  }
1717  if (item->static_values_off_ != 0 &&
1718      !CheckOffsetToTypeMap(item->static_values_off_, DexFile::kDexTypeEncodedArrayItem)) {
1719    return false;
1720  }
1721
1722  if (item->superclass_idx_ != DexFile::kDexNoIndex16) {
1723    LOAD_STRING_BY_TYPE(superclass_descriptor, item->superclass_idx_,
1724                        "inter_class_def_item superclass_idx")
1725    if (UNLIKELY(!IsValidDescriptor(superclass_descriptor) || superclass_descriptor[0] != 'L')) {
1726      ErrorStringPrintf("Invalid superclass: '%s'", superclass_descriptor);
1727      return false;
1728    }
1729  }
1730
1731  const DexFile::TypeList* interfaces = dex_file_->GetInterfacesList(*item);
1732  if (interfaces != NULL) {
1733    uint32_t size = interfaces->Size();
1734
1735    // Ensure that all interfaces refer to classes (not arrays or primitives).
1736    for (uint32_t i = 0; i < size; i++) {
1737      LOAD_STRING_BY_TYPE(inf_descriptor, interfaces->GetTypeItem(i).type_idx_,
1738                          "inter_class_def_item interface type_idx")
1739      if (UNLIKELY(!IsValidDescriptor(inf_descriptor) || inf_descriptor[0] != 'L')) {
1740        ErrorStringPrintf("Invalid interface: '%s'", inf_descriptor);
1741        return false;
1742      }
1743    }
1744
1745    /*
1746     * Ensure that there are no duplicates. This is an O(N^2) test, but in
1747     * practice the number of interfaces implemented by any given class is low.
1748     */
1749    for (uint32_t i = 1; i < size; i++) {
1750      uint32_t idx1 = interfaces->GetTypeItem(i).type_idx_;
1751      for (uint32_t j =0; j < i; j++) {
1752        uint32_t idx2 = interfaces->GetTypeItem(j).type_idx_;
1753        if (UNLIKELY(idx1 == idx2)) {
1754          ErrorStringPrintf("Duplicate interface: '%s'", dex_file_->StringByTypeIdx(idx1));
1755          return false;
1756        }
1757      }
1758    }
1759  }
1760
1761  // Check that references in class_data_item are to the right class.
1762  if (item->class_data_off_ != 0) {
1763    const byte* data = begin_ + item->class_data_off_;
1764    bool success;
1765    uint16_t data_definer = FindFirstClassDataDefiner(data, &success);
1766    if (!success) {
1767      return false;
1768    }
1769    if (UNLIKELY((data_definer != item->class_idx_) && (data_definer != DexFile::kDexNoIndex16))) {
1770      ErrorStringPrintf("Invalid class_data_item");
1771      return false;
1772    }
1773  }
1774
1775  // Check that references in annotations_directory_item are to right class.
1776  if (item->annotations_off_ != 0) {
1777    const byte* data = begin_ + item->annotations_off_;
1778    bool success;
1779    uint16_t annotations_definer = FindFirstAnnotationsDirectoryDefiner(data, &success);
1780    if (!success) {
1781      return false;
1782    }
1783    if (UNLIKELY((annotations_definer != item->class_idx_) &&
1784                 (annotations_definer != DexFile::kDexNoIndex16))) {
1785      ErrorStringPrintf("Invalid annotations_directory_item");
1786      return false;
1787    }
1788  }
1789
1790  ptr_ += sizeof(DexFile::ClassDef);
1791  return true;
1792}
1793
1794bool DexFileVerifier::CheckInterAnnotationSetRefList() {
1795  const DexFile::AnnotationSetRefList* list =
1796      reinterpret_cast<const DexFile::AnnotationSetRefList*>(ptr_);
1797  const DexFile::AnnotationSetRefItem* item = list->list_;
1798  uint32_t count = list->size_;
1799
1800  while (count--) {
1801    if (item->annotations_off_ != 0 &&
1802        !CheckOffsetToTypeMap(item->annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
1803      return false;
1804    }
1805    item++;
1806  }
1807
1808  ptr_ = reinterpret_cast<const byte*>(item);
1809  return true;
1810}
1811
1812bool DexFileVerifier::CheckInterAnnotationSetItem() {
1813  const DexFile::AnnotationSetItem* set = reinterpret_cast<const DexFile::AnnotationSetItem*>(ptr_);
1814  const uint32_t* offsets = set->entries_;
1815  uint32_t count = set->size_;
1816  uint32_t last_idx = 0;
1817
1818  for (uint32_t i = 0; i < count; i++) {
1819    if (*offsets != 0 && !CheckOffsetToTypeMap(*offsets, DexFile::kDexTypeAnnotationItem)) {
1820      return false;
1821    }
1822
1823    // Get the annotation from the offset and the type index for the annotation.
1824    const DexFile::AnnotationItem* annotation =
1825        reinterpret_cast<const DexFile::AnnotationItem*>(begin_ + *offsets);
1826    const uint8_t* data = annotation->annotation_;
1827    uint32_t idx = DecodeUnsignedLeb128(&data);
1828
1829    if (UNLIKELY(last_idx >= idx && i != 0)) {
1830      ErrorStringPrintf("Out-of-order entry types: %x then %x", last_idx, idx);
1831      return false;
1832    }
1833
1834    last_idx = idx;
1835    offsets++;
1836  }
1837
1838  ptr_ = reinterpret_cast<const byte*>(offsets);
1839  return true;
1840}
1841
1842bool DexFileVerifier::CheckInterClassDataItem() {
1843  ClassDataItemIterator it(*dex_file_, ptr_);
1844  bool success;
1845  uint16_t defining_class = FindFirstClassDataDefiner(ptr_, &success);
1846  if (!success) {
1847    return false;
1848  }
1849
1850  for (; it.HasNextStaticField() || it.HasNextInstanceField(); it.Next()) {
1851    LOAD_FIELD(field, it.GetMemberIndex(), "inter_class_data_item field_id", return false)
1852    if (UNLIKELY(field->class_idx_ != defining_class)) {
1853      ErrorStringPrintf("Mismatched defining class for class_data_item field");
1854      return false;
1855    }
1856  }
1857  for (; it.HasNextDirectMethod() || it.HasNextVirtualMethod(); it.Next()) {
1858    uint32_t code_off = it.GetMethodCodeItemOffset();
1859    if (code_off != 0 && !CheckOffsetToTypeMap(code_off, DexFile::kDexTypeCodeItem)) {
1860      return false;
1861    }
1862    LOAD_METHOD(method, it.GetMemberIndex(), "inter_class_data_item method_id", return false)
1863    if (UNLIKELY(method->class_idx_ != defining_class)) {
1864      ErrorStringPrintf("Mismatched defining class for class_data_item method");
1865      return false;
1866    }
1867  }
1868
1869  ptr_ = it.EndDataPointer();
1870  return true;
1871}
1872
1873bool DexFileVerifier::CheckInterAnnotationsDirectoryItem() {
1874  const DexFile::AnnotationsDirectoryItem* item =
1875      reinterpret_cast<const DexFile::AnnotationsDirectoryItem*>(ptr_);
1876  bool success;
1877  uint16_t defining_class = FindFirstAnnotationsDirectoryDefiner(ptr_, &success);
1878  if (!success) {
1879    return false;
1880  }
1881
1882  if (item->class_annotations_off_ != 0 &&
1883      !CheckOffsetToTypeMap(item->class_annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
1884    return false;
1885  }
1886
1887  // Field annotations follow immediately after the annotations directory.
1888  const DexFile::FieldAnnotationsItem* field_item =
1889      reinterpret_cast<const DexFile::FieldAnnotationsItem*>(item + 1);
1890  uint32_t field_count = item->fields_size_;
1891  for (uint32_t i = 0; i < field_count; i++) {
1892    LOAD_FIELD(field, field_item->field_idx_, "inter_annotations_directory_item field_id",
1893               return false)
1894    if (UNLIKELY(field->class_idx_ != defining_class)) {
1895      ErrorStringPrintf("Mismatched defining class for field_annotation");
1896      return false;
1897    }
1898    if (!CheckOffsetToTypeMap(field_item->annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
1899      return false;
1900    }
1901    field_item++;
1902  }
1903
1904  // Method annotations follow immediately after field annotations.
1905  const DexFile::MethodAnnotationsItem* method_item =
1906      reinterpret_cast<const DexFile::MethodAnnotationsItem*>(field_item);
1907  uint32_t method_count = item->methods_size_;
1908  for (uint32_t i = 0; i < method_count; i++) {
1909    LOAD_METHOD(method, method_item->method_idx_, "inter_annotations_directory_item method_id",
1910                return false)
1911    if (UNLIKELY(method->class_idx_ != defining_class)) {
1912      ErrorStringPrintf("Mismatched defining class for method_annotation");
1913      return false;
1914    }
1915    if (!CheckOffsetToTypeMap(method_item->annotations_off_, DexFile::kDexTypeAnnotationSetItem)) {
1916      return false;
1917    }
1918    method_item++;
1919  }
1920
1921  // Parameter annotations follow immediately after method annotations.
1922  const DexFile::ParameterAnnotationsItem* parameter_item =
1923      reinterpret_cast<const DexFile::ParameterAnnotationsItem*>(method_item);
1924  uint32_t parameter_count = item->parameters_size_;
1925  for (uint32_t i = 0; i < parameter_count; i++) {
1926    LOAD_METHOD(parameter_method, parameter_item->method_idx_,
1927                "inter_annotations_directory_item parameter method_id", return false)
1928    if (UNLIKELY(parameter_method->class_idx_ != defining_class)) {
1929      ErrorStringPrintf("Mismatched defining class for parameter_annotation");
1930      return false;
1931    }
1932    if (!CheckOffsetToTypeMap(parameter_item->annotations_off_,
1933        DexFile::kDexTypeAnnotationSetRefList)) {
1934      return false;
1935    }
1936    parameter_item++;
1937  }
1938
1939  ptr_ = reinterpret_cast<const byte*>(parameter_item);
1940  return true;
1941}
1942
1943bool DexFileVerifier::CheckInterSectionIterate(size_t offset, uint32_t count, uint16_t type) {
1944  // Get the right alignment mask for the type of section.
1945  size_t alignment_mask;
1946  switch (type) {
1947    case DexFile::kDexTypeClassDataItem:
1948      alignment_mask = sizeof(uint8_t) - 1;
1949      break;
1950    default:
1951      alignment_mask = sizeof(uint32_t) - 1;
1952      break;
1953  }
1954
1955  // Iterate through the items in the section.
1956  previous_item_ = NULL;
1957  for (uint32_t i = 0; i < count; i++) {
1958    uint32_t new_offset = (offset + alignment_mask) & ~alignment_mask;
1959    ptr_ = begin_ + new_offset;
1960    const byte* prev_ptr = ptr_;
1961
1962    // Check depending on the section type.
1963    switch (type) {
1964      case DexFile::kDexTypeStringIdItem: {
1965        if (!CheckInterStringIdItem()) {
1966          return false;
1967        }
1968        break;
1969      }
1970      case DexFile::kDexTypeTypeIdItem: {
1971        if (!CheckInterTypeIdItem()) {
1972          return false;
1973        }
1974        break;
1975      }
1976      case DexFile::kDexTypeProtoIdItem: {
1977        if (!CheckInterProtoIdItem()) {
1978          return false;
1979        }
1980        break;
1981      }
1982      case DexFile::kDexTypeFieldIdItem: {
1983        if (!CheckInterFieldIdItem()) {
1984          return false;
1985        }
1986        break;
1987      }
1988      case DexFile::kDexTypeMethodIdItem: {
1989        if (!CheckInterMethodIdItem()) {
1990          return false;
1991        }
1992        break;
1993      }
1994      case DexFile::kDexTypeClassDefItem: {
1995        if (!CheckInterClassDefItem()) {
1996          return false;
1997        }
1998        break;
1999      }
2000      case DexFile::kDexTypeAnnotationSetRefList: {
2001        if (!CheckInterAnnotationSetRefList()) {
2002          return false;
2003        }
2004        break;
2005      }
2006      case DexFile::kDexTypeAnnotationSetItem: {
2007        if (!CheckInterAnnotationSetItem()) {
2008          return false;
2009        }
2010        break;
2011      }
2012      case DexFile::kDexTypeClassDataItem: {
2013        if (!CheckInterClassDataItem()) {
2014          return false;
2015        }
2016        break;
2017      }
2018      case DexFile::kDexTypeAnnotationsDirectoryItem: {
2019        if (!CheckInterAnnotationsDirectoryItem()) {
2020          return false;
2021        }
2022        break;
2023      }
2024      default:
2025        ErrorStringPrintf("Unknown map item type %x", type);
2026        return false;
2027    }
2028
2029    previous_item_ = prev_ptr;
2030    offset = ptr_ - begin_;
2031  }
2032
2033  return true;
2034}
2035
2036bool DexFileVerifier::CheckInterSection() {
2037  const DexFile::MapList* map = reinterpret_cast<const DexFile::MapList*>(begin_ + header_->map_off_);
2038  const DexFile::MapItem* item = map->list_;
2039  uint32_t count = map->size_;
2040
2041  // Cross check the items listed in the map.
2042  while (count--) {
2043    uint32_t section_offset = item->offset_;
2044    uint32_t section_count = item->size_;
2045    uint16_t type = item->type_;
2046
2047    switch (type) {
2048      case DexFile::kDexTypeHeaderItem:
2049      case DexFile::kDexTypeMapList:
2050      case DexFile::kDexTypeTypeList:
2051      case DexFile::kDexTypeCodeItem:
2052      case DexFile::kDexTypeStringDataItem:
2053      case DexFile::kDexTypeDebugInfoItem:
2054      case DexFile::kDexTypeAnnotationItem:
2055      case DexFile::kDexTypeEncodedArrayItem:
2056        break;
2057      case DexFile::kDexTypeStringIdItem:
2058      case DexFile::kDexTypeTypeIdItem:
2059      case DexFile::kDexTypeProtoIdItem:
2060      case DexFile::kDexTypeFieldIdItem:
2061      case DexFile::kDexTypeMethodIdItem:
2062      case DexFile::kDexTypeClassDefItem:
2063      case DexFile::kDexTypeAnnotationSetRefList:
2064      case DexFile::kDexTypeAnnotationSetItem:
2065      case DexFile::kDexTypeClassDataItem:
2066      case DexFile::kDexTypeAnnotationsDirectoryItem: {
2067        if (!CheckInterSectionIterate(section_offset, section_count, type)) {
2068          return false;
2069        }
2070        break;
2071      }
2072      default:
2073        ErrorStringPrintf("Unknown map item type %x", type);
2074        return false;
2075    }
2076
2077    item++;
2078  }
2079
2080  return true;
2081}
2082
2083bool DexFileVerifier::Verify() {
2084  // Check the header.
2085  if (!CheckHeader()) {
2086    return false;
2087  }
2088
2089  // Check the map section.
2090  if (!CheckMap()) {
2091    return false;
2092  }
2093
2094  // Check structure within remaining sections.
2095  if (!CheckIntraSection()) {
2096    return false;
2097  }
2098
2099  // Check references from one section to another.
2100  if (!CheckInterSection()) {
2101    return false;
2102  }
2103
2104  return true;
2105}
2106
2107void DexFileVerifier::ErrorStringPrintf(const char* fmt, ...) {
2108  va_list ap;
2109  va_start(ap, fmt);
2110  DCHECK(failure_reason_.empty()) << failure_reason_;
2111  failure_reason_ = StringPrintf("Failure to verify dex file '%s': ", location_);
2112  StringAppendV(&failure_reason_, fmt, ap);
2113  va_end(ap);
2114}
2115
2116}  // namespace art
2117