Code: long long mkvparser::GetUIntLength(IMkvReader* pReader, long long pos,
                                   long& len) {
  assert(pReader);
  assert(pos >= 0);
 
   long long total, available;
 
   int status = pReader->Length(&total, &available);
  assert(status >= 0);
  assert((total < 0) || (available <= total));
 
   len = 1;
 
 if (pos >= available)
 return pos; // too few bytes available

 unsigned char b;

 
   status = pReader->Read(pos, 1, &b);
 
  if (status < 0)
     return status;
 
  assert(status == 0);
   if (b == 0)  // we can't handle u-int values larger than 8 bytes
     return E_FILE_FORMAT_INVALID;
 
 unsigned char m = 0x80;

 while (!(b & m)) {
    m >>= 1;
 ++len;
 }

 return 0; // success
}

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)
