[FFmpeg-devel] [PATCH 1/2] avformat/webmdashenc: Check codec types

[Andreas Rheinhardt]

Andreas Rheinhardt:
> The WebM DASH Manifest muxer only supports VP8, VP9, Vorbis and Opus,
> but there was no check for this. The codec type is used to get a pointer
> to a string containing the codec name or NULL if it is not one of those
> four codecs. Said pointer has then been used without further checks as
> string for the %s conversion specifier in an avio_printf()) call which
> is undefined behaviour.
> 
> This commit adds a check for the supported codec types.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavformat/webmdashenc.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/libavformat/webmdashenc.c b/libavformat/webmdashenc.c
> index d05b265330..182a361eae 100644
> --- a/libavformat/webmdashenc.c
> +++ b/libavformat/webmdashenc.c
> @@ -516,6 +516,14 @@ static int webm_dash_manifest_write_header(AVFormatContext *s)
>      double start = 0.0;
>      int ret;
>      WebMDashMuxContext *w = s->priv_data;
> +
> +    for (unsigned i = 0; i < s->nb_streams; i++) {
> +        enum AVCodecID codec_id = s->streams[i]->codecpar->codec_id;
> +        if ((codec_id != AV_CODEC_ID_VP8) && (codec_id != AV_CODEC_ID_VP9) &&
> +            (codec_id != AV_CODEC_ID_VORBIS) && (codec_id != AV_CODEC_ID_OPUS))
> +            return AVERROR(EINVAL);
> +    }
> +
>      ret = parse_adaptation_sets(s);
>      if (ret < 0) {
>          goto fail;
> 

If there are no objections, I intend to apply this patchset tomorrow.

- Andreas