[FFmpeg-devel] [PATCH 2/2] avformat/mvdec: Check stream numbers

[Michael Niedermayer]

On Sun, Feb 23, 2020 at 08:54:00PM +0000, Andreas Rheinhardt wrote:
> Michael Niedermayer:
> > Fixes: null pointer dereference
> > Fixes: 20768/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5638648978735104.fuzz
> > 
> > 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/mvdec.c | 6 ++++++
> >  1 file changed, 6 insertions(+)
> > 
> > diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c
> > index f9f7e38137..64166a84b1 100644
> > --- a/libavformat/mvdec.c
> > +++ b/libavformat/mvdec.c
> > @@ -363,6 +363,12 @@ static int mv_read_header(AVFormatContext *avctx)
> >          if ((ret = read_table(avctx, NULL, parse_global_var)) < 0)
> >              return ret;
> >  
> > +        if (mv->nb_audio_tracks < 0  || mv->nb_video_tracks < 0 ||
> > +           (mv->nb_audio_tracks == 0 && mv->nb_video_tracks == 0)) {
> > +            av_log(avctx, AV_LOG_ERROR, "Stream count is invalid.\n");
> > +            return AVERROR_INVALIDDATA;
> > +        }
> > +
> >          if (mv->nb_audio_tracks > 1) {
> >              avpriv_request_sample(avctx, "Multiple audio streams support");
> >              return AVERROR_PATCHWELCOME;
> > 
> LGTM.

will apply


> 
> - Andreas
> 
> PS: Is it actually allowed to set the channel_layout to stereo if
> there are more than two channels (as set_channels() does)?

id say code which sets this inconsistently should be fixed

thx

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

The misfortune of the wise is better than the prosperity of the fool.
-- Epicurus
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