[FFmpeg-cvslog] avformat/mxfdec: Ensure klv->key is initialized

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Jul 23 13:25:06 2025 +0200| [c6cb3ab7ff5a66db5d86f270d7c68547dac4da6a] | committer: Michael Niedermayer

avformat/mxfdec: Ensure klv->key is initialized

Fixes: read of uninitialized memory
Fixes: 391916474/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-4935250956845056

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c6cb3ab7ff5a66db5d86f270d7c68547dac4da6a
---

 libavformat/mxfdec.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index 0eed13d850..184e97256c 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -491,7 +491,9 @@ static int klv_read_packet(MXFContext *mxf, KLVPacket *klv, AVIOContext *pb)
         return AVERROR_INVALIDDATA;
 
     memcpy(klv->key, mxf_klv_key, 4);
-    avio_read(pb, klv->key + 4, 12);
+    int ret = ffio_read_size(pb, klv->key + 4, 12);
+    if (ret < 0)
+        return ret;
     length = klv_decode_ber_length(pb, &llen);
     if (length < 0)
         return length;