[FFmpeg-devel] [PATCH] avformat/oggenc: Don't free AVStream's priv_data, fix memleak

[Andreas Rheinhardt]

Andreas Rheinhardt:
> For FLAC, Speed, Opus and VP8 the Ogg muxer allocates two buffers
> for building the headers: The first for extradata in an Ogg-specific
> format and the second contains a Vorbiscomment. These buffers are
> reachable via pointers in the corresponding AVStream's priv_data.
> 
> If an error happens during building the headers, the AVStream's
> priv_data would be freed. This is pointless in general as it would be
> freed generically anyway, but here it is actively harmful: If the second
> of the aforementioned allocations fails, the first buffer would leak
> upon freeing priv_data.
> 
> This commit stops freeing priv_data manually, which allows the muxer to
> properly clean up in the deinit function.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavformat/oggenc.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/libavformat/oggenc.c b/libavformat/oggenc.c
> index fe89f23e36..fbd14fedf9 100644
> --- a/libavformat/oggenc.c
> +++ b/libavformat/oggenc.c
> @@ -546,7 +546,6 @@ static int ogg_init(AVFormatContext *s)
>                                               &st->metadata);
>              if (err) {
>                  av_log(s, AV_LOG_ERROR, "Error writing FLAC headers\n");
> -                av_freep(&st->priv_data);
>                  return err;
>              }
>          } else if (st->codecpar->codec_id == AV_CODEC_ID_SPEEX) {
> @@ -555,7 +554,6 @@ static int ogg_init(AVFormatContext *s)
>                                                &st->metadata);
>              if (err) {
>                  av_log(s, AV_LOG_ERROR, "Error writing Speex headers\n");
> -                av_freep(&st->priv_data);
>                  return err;
>              }
>          } else if (st->codecpar->codec_id == AV_CODEC_ID_OPUS) {
> @@ -564,7 +562,6 @@ static int ogg_init(AVFormatContext *s)
>                                               &st->metadata, s->chapters, s->nb_chapters);
>              if (err) {
>                  av_log(s, AV_LOG_ERROR, "Error writing Opus headers\n");
> -                av_freep(&st->priv_data);
>                  return err;
>              }
>          } else if (st->codecpar->codec_id == AV_CODEC_ID_VP8) {
> @@ -572,7 +569,6 @@ static int ogg_init(AVFormatContext *s)
>                                              s->flags & AVFMT_FLAG_BITEXACT);
>              if (err) {
>                  av_log(s, AV_LOG_ERROR, "Error writing VP8 headers\n");
> -                av_freep(&st->priv_data);
>                  return err;
>              }
>          } else {
> @@ -585,7 +581,7 @@ static int ogg_init(AVFormatContext *s)
>                                        st->codecpar->codec_id == AV_CODEC_ID_VORBIS ? 30 : 42,
>                                        (const uint8_t**)oggstream->header, oggstream->header_len) < 0) {
>                  av_log(s, AV_LOG_ERROR, "Extradata corrupted\n");
> -                av_freep(&st->priv_data);
> +                oggstream->header[1] = NULL;
>                  return AVERROR_INVALIDDATA;
>              }
>  
> @@ -755,7 +751,6 @@ static void ogg_free(AVFormatContext *s)
>              av_freep(&oggstream->header[0]);
>          }
>          av_freep(&oggstream->header[1]);
> -        av_freep(&st->priv_data);
>      }
>  
>      while (p) {
> 
Will apply this tomorrow if there are no objections.

- Andreas