Copilot commented on code in PR #3854:
URL: https://github.com/apache/avro/pull/3854#discussion_r3567570474
##########
lang/c++/impl/DataFile.cc:
##########
@@ -627,12 +679,30 @@ void DataFileReaderBase::readDataBlock() {
const uint8_t *data;
size_t len;
+ const size_t maxLength = maxDecompressLength();
Review Comment:
In the deflate path, `maxLength` can be configured up to `size_t` max, but
zlib’s `z_stream::total_out` is a `uLong` (32-bit on some platforms, e.g.
Windows). If `AVRO_MAX_DECOMPRESS_LENGTH` is set above
`std::numeric_limits<uLong>::max()`, `zs.total_out` can overflow, which would
make buffer indexing (`uncompressed.data() + zs.total_out`) incorrect and risks
memory corruption. Clamp the effective limit for the deflate/zlib branch to
what zlib counters can represent (or fail early) to keep indexing safe across
platforms.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
