Validate safe_browsing::dmg::UDIFBlock data before attempting to read at its offsets.

chrome/utility/safe_browsing/mac/udif.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_
 #define CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_
 
 #include <CoreFoundation/CoreFoundation.h>
 #include <stddef.h>
 #include <stdint.h>
@@ skipping 58 matching lines @@
   size_t GetPartitionSize(size_t part_number);
 
   // Returns a stream of the raw partition data for the given partition
   // number.
   std::unique_ptr<ReadStream> GetPartitionReadStream(size_t part_number);
 
  private:
   // Parses the blkx plist trailer structure.
   bool ParseBlkx();
 
-  // Reads the data pointed to by the block |chunk|, decompressing it as
-  // necessary, into the out-buffer |decompressed_data|.
-  bool ReadBlockChunk(const UDIFBlockChunk* chunk,
-                      std::vector<uint8_t>* decompressed_data);
-
   ReadStream* const stream_;  // The stream backing the UDIF image. Weak.
   std::vector<std::string> partition_names_;  // The names of all partitions.
   ScopedVector<const UDIFBlock> blocks_;  // All blocks in the UDIF image.
   uint16_t block_size_;  // The image's block size, in bytes.
 
   DISALLOW_COPY_AND_ASSIGN(UDIFParser);
 };
 
 }  // namespace dmg
 }  // namespace safe_browsing
 
 #endif  // CHROME_UTILITY_SAFE_BROWSING_MAC_UDIF_H_