UUIDs can have their high bit set

mkvparser::UnserializeUInt() assumes that unsigned values never have
their high bit set. This is too limiting for UUIDs. In addition, the
Chapters::Atom::Parse() method would truncate a "negative" 64-bit UUID
value to 32 bits and return the truncated value as a status code.
This value then might or might not be treated as an error by the caller
depending on whether the truncated value was itself negative.

b/13744158

Change-Id: I95d9ba60d1e16a0de25215c4e67d694617488d59

1 files changed, 4 insertions, 3 deletions

diff --git a/libwebm/mkvparser.cpp b/libwebm/mkvparser.cpp
index d7a8fe1..594f302 100644
--- a/libwebm/mkvparser.cpp
+++ b/libwebm/mkvparser.cpp
@@ -4662,10 +4662,11 @@ long Chapters::Atom::Parse(
         }
         else if (id == 0x33C4)  // UID ID
         {
-            const long long val = UnserializeUInt(pReader, pos, size);
+            long long val;
+            status = UnserializeInt(pReader, pos, size, val);
 
-            if (val < 0)  // error
-                return static_cast<long>(val);
+            if (status < 0)  // error
+                return status;
 
             m_uid = val;
         }