[FFmpeg-devel] [PATCH] avcodec/v210dec: Fix alignment check for AVX2

[James Darnley]

On 2019-05-18 09:39, Michael Niedermayer wrote:
> Fixes: "null pointer dereference"
> Fixes: 14551/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_V210_fuzzer-5088609952071680
> 
> 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/v210dec.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/v210dec.c b/libavcodec/v210dec.c
> index bc1e1d34ff..5a33d8c089 100644
> --- a/libavcodec/v210dec.c
> +++ b/libavcodec/v210dec.c
> @@ -104,7 +104,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
>          && avpkt->size - 64 >= stride * avctx->height)
>          psrc += 64;
>  
> -    aligned_input = !((uintptr_t)psrc & 0xf) && !(stride & 0xf);
> +    aligned_input = !((uintptr_t)psrc & 0x1f) && !(stride & 0x1f);
>      if (aligned_input != s->aligned_input) {
>          s->aligned_input = aligned_input;
>          ff_v210dec_init(s);
> 

Ah yes, that'll be needed after the recent addition of avx2.  LGTM and
sorry.

I object to the commit message though because it isn't a "null pointer
dereference" but if that is the error as reported by the tool then keep
it as is.