[FFmpeg-devel] [PATCH 2/4] avcodec/hevc_ps: Fix integer overflow with num_tile_rows

[James Almer]

On 6/13/2019 3:32 PM, Michael Niedermayer wrote:
> Fixes: signed integer overflow: -2147483648 - 1 cannot be represented in type 'int'
> Fixes: 14880/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-5130977304641536
> 
> 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/hevc_ps.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavcodec/hevc_ps.c b/libavcodec/hevc_ps.c
> index 80df417e4f..0ed6682bb4 100644
> --- a/libavcodec/hevc_ps.c
> +++ b/libavcodec/hevc_ps.c
> @@ -1596,7 +1596,7 @@ int ff_hevc_decode_nal_pps(GetBitContext *gb, AVCodecContext *avctx,
>          if (pps->num_tile_rows <= 0 ||
>              pps->num_tile_rows >= sps->height) {
>              av_log(avctx, AV_LOG_ERROR, "num_tile_rows_minus1 out of range: %d\n",
> -                   pps->num_tile_rows - 1);
> +                   pps->num_tile_rows - 1U);

The proper fix for this is making pps->num_tile_rows/cols unsigned. The
minimum allowed value for num_tile_{rows,cols}_minus1 is 0.

>              ret = AVERROR_INVALIDDATA;
>              goto err;
>          }
>