[FFmpeg-devel] [PATCH 2/2] avcodec/huffyuvdec: Check that slices do not exceed frame height

[Paul B Mahol]

On 1/6/19, Michael Niedermayer <michael at niedermayer.cc> wrote:
> Fixes: Out of array access
> Fixes:
> 12367/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5662313959391232
> Fixes:
> 12370/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5670984961490944
> Fixes:
> 12376/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5644026183680000
> Fixes:
> 12383/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5722087214284800
> Fixes:
> 12390/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5696653095337984
> Fixes:
> 12408/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5729689379799040
>
> 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/huffyuvdec.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/libavcodec/huffyuvdec.c b/libavcodec/huffyuvdec.c
> index dfe3585e6e..8226c07743 100644
> --- a/libavcodec/huffyuvdec.c
> +++ b/libavcodec/huffyuvdec.c
> @@ -1254,7 +1254,8 @@ static int decode_frame(AVCodecContext *avctx, void
> *data, int *got_frame,
>          slices_info_offset = AV_RL32(avpkt->data + buf_size - 4);
>          slice_height = AV_RL32(avpkt->data + buf_size - 8);
>          nb_slices = AV_RL32(avpkt->data + buf_size - 12);
> -        if (nb_slices * 8LL + slices_info_offset > buf_size - 16 ||
> slice_height <= 0)
> +        if (nb_slices * 8LL + slices_info_offset > buf_size - 16 ||
> +            slice_height <= 0 || nb_slices * (uint64_t)slice_height >
> height)
>              return AVERROR_INVALIDDATA;
>      } else {
>          slice_height = height;
> --
> 2.20.1
>

ok