[FFmpeg-devel] [PATCH 2/2] avcodec/gemdec: Check tag & planes before image allocation

[Peter Ross]

On Sun, Nov 28, 2021 at 07:55:14PM +0100, Michael Niedermayer wrote:
> Fixes: Timeout
> Fixes: 41083/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_GEM_fuzzer-5843826518917120
> 
> 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/gemdec.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/libavcodec/gemdec.c b/libavcodec/gemdec.c
> index 2464dda8a7e..eee21a50d4b 100644
> --- a/libavcodec/gemdec.c
> +++ b/libavcodec/gemdec.c
> @@ -157,6 +157,14 @@ static int gem_decode_frame(AVCodecContext *avctx,
>      if (header_size >= 11)
>          tag = bytestream2_peek_be32(&gb);
>  
> +    if (tag == AV_RB32("STTT") || tag == AV_RB32("TIMG") || tag == AV_RB32("XIMG") ||
> +        planes == 1 || planes == 2 || planes == 3 || planes == 4 ||
> +        planes == 8 || planes == 16 || planes == 24) {
> +    } else {
> +        avpriv_request_sample(avctx, "planes=%d", planes);
> +        return AVERROR_PATCHWELCOME;
> +    }
> +
>      if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
>          return ret;
>  
> @@ -236,9 +244,6 @@ static int gem_decode_frame(AVCodecContext *avctx,
>          planes = 1;
>          row_width = avctx->width * pixel_size;
>          put_lines = put_lines_bytes;
> -    } else {
> -        avpriv_request_sample(avctx, "planes=%d", planes);
> -        return AVERROR_PATCHWELCOME;
>      }
>  
>      ret = av_reallocp_array(&avctx->priv_data, planes, row_width);

please apply

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