[FFmpeg-devel] [PATCH] avcodec/vp3: Check eob_run

[Michael Niedermayer]

On Fri, Feb 09, 2018 at 04:41:44AM +0100, Michael Niedermayer wrote:
> Fixes: out of array access
> Fixes: 5919/clusterfuzz-testcase-minimized-5859311382167552
> 
> 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 | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/libavcodec/vp3.c b/libavcodec/vp3.c
> index cf9c57f5fa..120c20f349 100644
> --- a/libavcodec/vp3.c
> +++ b/libavcodec/vp3.c
> @@ -978,6 +978,9 @@ static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
>              if (eob_run_get_bits[token])
>                  eob_run += get_bits(gb, eob_run_get_bits[token]);
>  
> +            if (!eob_run)
> +                return AVERROR_INVALIDDATA;
> +
>              // record only the number of blocks ended in this plane,
>              // any spill will be recorded in the next plane.
>              if (eob_run > num_coeffs - coeff_i) {

this is incorrect for theora, (its correct for vp3) i will post a better patch

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

No great genius has ever existed without some touch of madness. -- Aristotle
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