[FFmpeg-devel] [PATCH 1/9] avformat/segafilm: Check that there is a stream

[Michael Niedermayer]

On Thu, Oct 22, 2020 at 07:20:49AM +0200, Andreas Rheinhardt wrote:
> Michael Niedermayer:
> > Fixes: assertion failure
> > Fixes: 26472/clusterfuzz-testcase-minimized-ffmpeg_dem_SEGAFILM_fuzzer-5759751591559168
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavformat/segafilm.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/libavformat/segafilm.c b/libavformat/segafilm.c
> > index 4d14b81d16..17592c905e 100644
> > --- a/libavformat/segafilm.c
> > +++ b/libavformat/segafilm.c
> > @@ -144,6 +144,9 @@ static int film_read_header(AVFormatContext *s)
> >          film->video_type = AV_CODEC_ID_NONE;
> >      }
> >  
> > +    if (!film->video_type && !film->audio_type)
> > +        return AVERROR_INVALIDDATA;
> > +
> >      /* initialize the decoder streams */
> >      if (film->video_type) {
> >          st = avformat_new_stream(s, NULL);
> > 
> This basically presumes that the value of AV_CODEC_ID_NONE is zero. This
> assumption should be avoided (as can be done easily here). LGTM apart
> from that.

This decoder assumes AV_CODEC_ID_NONE is zero in 5 other places already.
But ill fix all cases in this decoder.
But even with that changing AV_CODEC_ID_NONE to 1 causes
2970 fate tests to fail

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Into a blind darkness they enter who follow after the Ignorance,
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