[FFmpeg-devel] [PATCH 1/2] avcodec/wmalosslessdec: move channel check up

[Andreas Rheinhardt]

On Wed, Jan 15, 2020 at 1:25 AM Michael Niedermayer <michael at niedermayer.cc>
wrote:

> Fixes: out of array access
> Fixes: 2nd part of
> 18429/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMALOSSLESS_fuzzer-6210814364614656
>
> Found-by: continuous fuzzing process
> https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by
> <https://github.com/google/oss-fuzz/tree/master/projects/ffmpegSigned-off-by>:
> Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavcodec/wmalosslessdec.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
> index d2f9d4a70f..2b97c2a848 100644
> --- a/libavcodec/wmalosslessdec.c
> +++ b/libavcodec/wmalosslessdec.c
> @@ -189,6 +189,16 @@ static av_cold int decode_init(AVCodecContext *avctx)
>          return AVERROR(EINVAL);
>      }
>
> +    if (avctx->channels < 0) {
> +        av_log(avctx, AV_LOG_ERROR, "invalid number of channels %d\n",
> +               avctx->channels);
> +        return AVERROR_INVALIDDATA;
> +    } else if (avctx->channels > WMALL_MAX_CHANNELS) {
> +        avpriv_request_sample(avctx,
> +                              "More than %d channels",
> WMALL_MAX_CHANNELS);
>

This looks like it could benefit from AV_STRINGIFY. LGTM apart from that.

- Andreas