[FFmpeg-cvslog] avformat/mxfdec: More offset_temp checks

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Sep 12 22:29:04 2024 +0200| [5a96aa435af0d66bdec52ee115cf4dd971855fcd] | committer: Michael Niedermayer

avformat/mxfdec: More offset_temp checks

Fixes: signed integer overflow: 9223372036854775807 - -1927491430256034080 cannot be represented in type 'long'
Fixes: 70607/clusterfuzz-testcase-minimized-ffmpeg_dem_MXF_fuzzer-5282235077951488

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=5a96aa435af0d66bdec52ee115cf4dd971855fcd
---

 libavformat/mxfdec.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index 2a076931ed..17a04e16f1 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -1921,6 +1921,11 @@ static int mxf_edit_unit_absolute_offset(MXFContext *mxf, MXFIndexTable *index_t
             return mxf_absolute_bodysid_offset(mxf, index_table->body_sid, offset_temp, offset_out, partition_out);
         } else {
             /* EditUnitByteCount == 0 for VBR indexes, which is fine since they use explicit StreamOffsets */
+            if (s->edit_unit_byte_count && (s->index_duration > INT64_MAX / s->edit_unit_byte_count ||
+                s->edit_unit_byte_count * s->index_duration > INT64_MAX - offset_temp)
+            )
+                return AVERROR_INVALIDDATA;
+
             offset_temp += s->edit_unit_byte_count * s->index_duration;
         }
     }