Re: [FFmpeg-devel] [PATCH 5/5] avformat/mvdec: Check bytes_per_sample

[John-Paul Stewart <jpstewart@personalprojects.net>]

On 2021-12-23 16:15, Michael Niedermayer wrote:
> Fixes: division by zero
> Fixes: 42814/clusterfuzz-testcase-minimized-ffmpeg_dem_MV_fuzzer-4787014237552640
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> ---
>  libavformat/mvdec.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c
> index 1a5012e5076..390f6ba4de8 100644
> --- a/libavformat/mvdec.c
> +++ b/libavformat/mvdec.c
> @@ -366,6 +366,9 @@ static int mv_read_header(AVFormatContext *avctx)
>              avpriv_request_sample(avctx, "Audio compression (format %i)", v);
>          }
>  
> +        if (bytes_per_sample <= 0)
> +            return AVERROR_INVALIDDATA;
> +

bytes_per_sample is uint32_t so it can never be less than zero.

bytes_per_sample will be zero for movie files with no audio, so that is
not necessarily invalid data.

I can't offer a better suggestion at the moment, though.  I'll see if
can come up with something, unless one of you guys gets to it first.
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".