[FFmpeg-devel] [PATCH v4 2/9] avformat/utils: unref packet on AVInputFormat.read_packet() failure

[James Almer]

On 9/20/2019 5:39 PM, Andreas Rheinhardt wrote:
> From: James Almer <jamrial at gmail.com>
> 
> Demuxers may have allocated a packet before encountering an error and aborting.
> 
> Fixes ticket #8150
> 
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
> Earlier versions of this patchset used av_init_packet() together with
> setting the size and data to zero/NULL. This would have caused memleaks
> when the packet contained data that needs to be freed/unreferenced,
> whereas this approach here runs the risk of double freeing. I consider
> the risk of the latter much lower than the risk of the former and have
> therefore included this patch in this patchset.
> 
>  libavformat/utils.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/libavformat/utils.c b/libavformat/utils.c
> index 652642a71b..e348df3269 100644
> --- a/libavformat/utils.c
> +++ b/libavformat/utils.c
> @@ -854,6 +854,8 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
>          av_init_packet(pkt);
>          ret = s->iformat->read_packet(s, pkt);
>          if (ret < 0) {
> +            av_packet_unref(pkt);
> +
>              /* Some demuxers return FFERROR_REDO when they consume
>                 data and discard it (ignored streams, junk, extradata).
>                 We must re-call the demuxer to get the real packet. */

Applied.