[FFmpeg-devel] [PATCH 2/2] avformat/utils: Fix memleaks

[James Almer]

On 9/24/2019 1:31 PM, Andreas Rheinhardt wrote:
> ff_read_packet had potential memleaks:
> 1. If av_packet_make_refcounted fails, it means that the packet is not
> refcounted, but it could nevertheless carry side data and therefore
> needs to be unreferenced.
> 2. If putting a packet on a packet list fails, it wasn't unreferenced.
> 
> Furthermore, read_frame_internal leaked a packet's (side) data if a
> context update was required and failed.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavformat/utils.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/libavformat/utils.c b/libavformat/utils.c
> index d8ef5fe54c..ff6aecbf3c 100644
> --- a/libavformat/utils.c
> +++ b/libavformat/utils.c
> @@ -872,8 +872,10 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
>          }
>  
>          err = av_packet_make_refcounted(pkt);
> -        if (err < 0)
> +        if (err < 0) {
> +            av_packet_unref(pkt);
>              return err;
> +        }
>  
>          if ((s->flags & AVFMT_FLAG_DISCARD_CORRUPT) &&
>              (pkt->flags & AV_PKT_FLAG_CORRUPT)) {
> @@ -914,8 +916,10 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
>          err = ff_packet_list_put(&s->internal->raw_packet_buffer,
>                                   &s->internal->raw_packet_buffer_end,
>                                   pkt, 0);
> -        if (err)
> +        if (err < 0) {
> +            av_packet_unref(pkt);
>              return err;
> +        }
>          s->internal->raw_packet_buffer_remaining_size -= pkt->size;
>  
>          if ((err = probe_codec(s, st, pkt)) < 0)
> @@ -1608,15 +1612,19 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
>              }
>  
>              ret = avcodec_parameters_to_context(st->internal->avctx, st->codecpar);
> -            if (ret < 0)
> +            if (ret < 0) {
> +                av_packet_unref(&cur_pkt);
>                  return ret;
> +            }
>  
>  #if FF_API_LAVF_AVCTX
>  FF_DISABLE_DEPRECATION_WARNINGS
>              /* update deprecated public codec context */
>              ret = avcodec_parameters_to_context(st->codec, st->codecpar);
> -            if (ret < 0)
> +            if (ret < 0) {
> +                av_packet_unref(&cur_pkt);
>                  return ret;
> +            }
>  FF_ENABLE_DEPRECATION_WARNINGS
>  #endif

Applied this set of two patches.