[FFmpeg-devel] [PATCH] golomb: check log validity before shifting

[Paul B Mahol]

On 1/12/13, Michael Niedermayer <michaelni at gmx.at> wrote:
> Fixes invalid right shift in fate-cavs
>
> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> ---
>  libavcodec/golomb.h |    8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
> index 0629c78..e3a35e9 100644
> --- a/libavcodec/golomb.h
> +++ b/libavcodec/golomb.h
> @@ -66,10 +66,14 @@ static inline int get_ue_golomb(GetBitContext *gb){
>          return ff_ue_golomb_vlc_code[buf];
>      }else{
>          log= 2*av_log2(buf) - 31;
> -        buf>>= log;
> -        buf--;
>          LAST_SKIP_BITS(re, gb, 32 - log);
>          CLOSE_READER(re, gb);
> +        if (log < 0) {
> +            av_log(0, AV_LOG_ERROR, "Invalid UE golomb code\n");
> +            return AVERROR_INVALIDDATA;
> +        }
> +        buf>>= log;
> +        buf--;
>
>          return buf;
>      }
> --
> 1.7.9.5

I'm not sure about return code, most code that calls it never check value.