[FFmpeg-cvslog] avformat/mxfdec: Check edit_unit for being larger than signed 64bit

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Dec  1 03:53:42 2024 +0100| [f7cc023f06c42fce8652b8d8f8cf981d36aeed2e] | committer: Michael Niedermayer

avformat/mxfdec: Check edit_unit for being larger than signed 64bit

Fixes: signed integer overflow: 2 * -4962931467012268000 cannot be represented in type 'long'
Fixes: 376496313/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-4921469185884160

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=f7cc023f06c42fce8652b8d8f8cf981d36aeed2e
---

 libavformat/mxfdec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index 1bae523c2a..02db8d4cb3 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -1928,6 +1928,8 @@ static int mxf_edit_unit_absolute_offset(MXFContext *mxf, MXFIndexTable *index_t
     // clamp to actual range of index
     index_end = av_sat_add64(last_segment->index_start_position, last_segment->index_duration);
     edit_unit = FFMAX(FFMIN(edit_unit, index_end), first_segment->index_start_position);
+    if (edit_unit < 0)
+        return AVERROR_PATCHWELCOME;
 
     // guess which table segment this edit unit is in
     // saturation is fine since it's just a guess