[FFmpeg-devel] [PATCH 2/3] avcodec/vp3: Check version in all cases when VP4 code is not built

[Peter Ross]

On Tue, Nov 30, 2021 at 08:59:34PM +0100, Michael Niedermayer wrote:
> Fixes: out of array read
> Fixes: 40284/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VP3_fuzzer-4599568176644096
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavcodec/vp3.c | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
> index 16726080b35..5b9ba60f499 100644
> --- a/libavcodec/vp3.c
> +++ b/libavcodec/vp3.c
> @@ -2685,7 +2685,14 @@ static int vp3_decode_frame(AVCodecContext *avctx,
>              skip_bits(&gb, 4); /* width code */
>              skip_bits(&gb, 4); /* height code */
>              if (s->version) {
> -                s->version = get_bits(&gb, 5);
> +                int version = get_bits(&gb, 5);
> +#if !CONFIG_VP4_DECODER
> +                if (version >= 2) {
> +                    av_log(avctx, AV_LOG_ERROR, "This build does not support decoding VP4.\n");
> +                    return AVERROR_DECODER_NOT_FOUND;
> +                }
> +#endif
> +                s->version = version;
>                  if (avctx->frame_number == 0)
>                      av_log(s->avctx, AV_LOG_DEBUG,
>                             "VP version: %d\n", s->version);

please apply.

-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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