[FFmpeg-devel] [PATCH v1 5/6] avformat/rl2: use av_freep instead of av_free to avoid invalid access if alloc failed

[Andreas Rheinhardt]

lance.lmwang at gmail.com:
> From: Limin Wang <lance.lmwang at gmail.com>
> 
> Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> ---
>  libavformat/rl2.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/libavformat/rl2.c b/libavformat/rl2.c
> index d847d9aaa8..3d38ffe8ba 100644
> --- a/libavformat/rl2.c
> +++ b/libavformat/rl2.c
> @@ -163,9 +163,9 @@ static av_cold int rl2_read_header(AVFormatContext *s)
>      chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
>  
>      if(!chunk_size || !audio_size || !chunk_offset){
> -        av_free(chunk_size);
> -        av_free(audio_size);
> -        av_free(chunk_offset);
> +        av_freep(&chunk_size);
> +        av_freep(&audio_size);
> +        av_freep(&chunk_offset);
>          return AVERROR(ENOMEM);
>      }
>  
What invalid accesses are you talking about? You are just setting
local variables to NULL (in addition to freeing them) and you do this
immediately before leaving the function which ends their lifetime
anyway. So I don't really know how this should help prevent invalid
accesses.

- Andreas