Code: void CuePoint::TrackPosition::Parse(IMkvReader* pReader, long long start_,
                                     long long size_) {
   const long long stop = start_ + size_;
   long long pos = start_;

  m_track = -1;
  m_pos = -1;
  m_block = 1; // default


   while (pos < stop) {
     long len;
 
    const long long id = ReadUInt(pReader, pos, len);
    assert(id >= 0);  // TODO
    assert((pos + len) <= stop);
 
     pos += len;  // consume ID
 
     const long long size = ReadUInt(pReader, pos, len);
    assert(size >= 0);
    assert((pos + len) <= stop);
 
     pos += len;  // consume Size field
    assert((pos + size) <= stop);
 
     if (id == 0x77)  // CueTrack ID
       m_track = UnserializeUInt(pReader, pos, size);

 else if (id == 0x71) // CueClusterPos ID
      m_pos = UnserializeUInt(pReader, pos, size);

 else if (id == 0x1378) // CueBlockNumber

       m_block = UnserializeUInt(pReader, pos, size);
 
     pos += size;  // consume payload
    assert(pos <= stop);
   }
 
  assert(m_pos >= 0);
  assert(m_track > 0);
 }

Vulnerability Type: DoS Exec Code Mem. Corr. 
CWE ID: CWE-20
Summary: libvpx in libwebm in mediaserver in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-06-01 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted mkv file, aka internal bug 23167726.
Commit Message: external/libvpx/libwebm: Update snapshot

Update libwebm snapshot. This update contains security fixes from upstream.

Upstream git hash: 229f49347d19b0ca0941e072b199a242ef6c5f2b

BUG=23167726

Change-Id: Id3e140e7b31ae11294724b1ecfe2e9c83b4d4207
(cherry picked from commit d0281a15b3c6bd91756e453cc9398c5ef412d99a)
