[FFmpeg-devel] [PATCH 4/5] avutil/lfg: Correct index type to avoid undefined behavior

[James Almer]

On 10/19/2019 5:39 PM, Michael Niedermayer wrote:
> Fixes: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
> Fixes: 18333/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_COMFORTNOISE_fuzzer-5668481831272448
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavutil/lfg.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavutil/lfg.h b/libavutil/lfg.h
> index 03f779ad8a..8b18df2cea 100644
> --- a/libavutil/lfg.h
> +++ b/libavutil/lfg.h
> @@ -26,7 +26,7 @@
>  
>  typedef struct AVLFG {
>      unsigned int state[64];
> -    int index;
> +    unsigned index;
>  } AVLFG;

Wouldn't this be considered an API change?

>  
>  void av_lfg_init(AVLFG *c, unsigned int seed);
>