[FFmpeg-cvslog] avformat/mxfdec: Check body_offset

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Apr 26 03:46:33 2024 +0200| [20a6bfda0f7c6447ac94611736cee6e9ce6972a0] | committer: Michael Niedermayer

avformat/mxfdec: Check body_offset

Fixes: signed integer overflow: 538976288 - -9223372036315799520 cannot be represented in type 'long'
Fixes: 68060/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-5523457266745344

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=20a6bfda0f7c6447ac94611736cee6e9ce6972a0
---

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

diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index 233d614f78..e65cec74c2 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -791,6 +791,9 @@ static int mxf_read_partition_pack(void *arg, AVIOContext *pb, int tag, int size
     partition->index_sid = avio_rb32(pb);
     partition->body_offset = avio_rb64(pb);
     partition->body_sid = avio_rb32(pb);
+    if (partition->body_offset < 0)
+        return AVERROR_INVALIDDATA;
+
     if (avio_read(pb, op, sizeof(UID)) != sizeof(UID)) {
         av_log(mxf->fc, AV_LOG_ERROR, "Failed reading UID\n");
         return AVERROR_INVALIDDATA;