[FFmpeg-devel] [PATCH 3/3] avcodec/wavpack: Do not allow the sample format to change between channels

[David Bryant]

On 6/3/20 4:19 PM, Michael Niedermayer wrote:
> Fixes: out of array access
> Fixes: 22692/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WAVPACK_fuzzer-5678686190960640
>
> 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/wavpack.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/libavcodec/wavpack.c b/libavcodec/wavpack.c
> index ead57063c8..f77548e5a5 100644
> --- a/libavcodec/wavpack.c
> +++ b/libavcodec/wavpack.c
> @@ -1129,6 +1129,9 @@ static int wavpack_decode_block(AVCodecContext *avctx, int block_no,
>      else
>          sample_fmt          = AV_SAMPLE_FMT_S32P;
>  
> +    if (wc->ch_offset && avctx->sample_fmt != sample_fmt)
> +        return AVERROR_INVALIDDATA;
> +
>      bpp            = av_get_bytes_per_sample(sample_fmt);
>      orig_bpp       = ((s->frame_flags & 0x03) + 1) << 3;
>      multiblock     = (s->frame_flags & WV_SINGLE_BLOCK) != WV_SINGLE_BLOCK;

Looks reasonable to me and passes my local test suite. Thanks!

-David