[FFmpeg-devel] [PATCH 5/7] avformat/mxfdec: More offset_temp checks

[Tomas Härdin]

fre 2024-09-13 klockan 01:33 +0200 skrev Michael Niedermayer:
> 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
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavformat/mxfdec.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> index 8eae9f87afa..41281c5196d 100644
> --- a/libavformat/mxfdec.c
> +++ b/libavformat/mxfdec.c
> @@ -1924,6 +1924,11 @@ 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;

Actually there's one minor issue: kdevelop warns about lack of
parenthesis around the && and ||

/Tomas