[FFmpeg-devel] [PATCH 2/2] avformat/subtitles: Check for NOPTS in ff_subtitles_queue_finalize()

[Michael Niedermayer]

On Wed, Jun 24, 2020 at 02:10:09PM +0200, Nicolas George wrote:
> Michael Niedermayer (12020-06-24):
> > On Tue, Jun 23, 2020 at 02:08:44PM +0200, Nicolas George wrote:
> > > Michael Niedermayer (12020-06-23):
> > > > Fixes; signed integer overflow: 1 - -9223372036854775808 cannot be represented in type 'long'
> > > > Fixes: 23490/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5133490093031424
> > > > 
> > > > 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/subtitles.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/libavformat/subtitles.c b/libavformat/subtitles.c
> > > > index ad7f68938e..ccab80391f 100644
> > > > --- a/libavformat/subtitles.c
> > > > +++ b/libavformat/subtitles.c
> > > > @@ -202,7 +202,7 @@ void ff_subtitles_queue_finalize(void *log_ctx, FFDemuxSubtitlesQueue *q)
> > > >            q->sort == SUB_SORT_TS_POS ? cmp_pkt_sub_ts_pos
> > > >                                       : cmp_pkt_sub_pos_ts);
> > > >      for (i = 0; i < q->nb_subs; i++)
> > > > -        if (q->subs[i].duration < 0 && i < q->nb_subs - 1)
> > > > +        if (q->subs[i].duration < 0 && i < q->nb_subs - 1 && q->subs[i].pts != AV_NOPTS_VALUE)
> > > >              q->subs[i].duration = q->subs[i + 1].pts - q->subs[i].pts;
> > > >  
> > > >      if (!q->keep_duplicates)
> > > 
> > > Having no PTS at this point makes no sense. We should examine why it
> > > arrived there. 
> > 
> > it comes from microdvddec in this case, it can be fixed for example
> > with the following: (i do not know if these are all cases which can
> > generate this)
> 
> Thanks. It seems like a much more correct fix. We can see in
> $FATE/sub/MicroDVD_capability_tester.sub that all lines have a number in
> the first pair of braces except DEFAULT, which is parsed separately.
> 
> > commit 06eff32c6e4100b70a3a215a0756580a6fa124b5 (HEAD -> master)
> > Author: Michael Niedermayer <michael at niedermayer.cc>
> > Date:   Tue Jun 23 01:43:14 2020 +0200
> > 
> 
> >     iavformat/microdvddec: Skip NOPTS values
> 
> skip malformed lines without frame number.
> 
> >     
> >     Fixes; signed integer overflow: 1 - -9223372036854775808 cannot be represented in type 'long'
> 
> Colon / semicolon.

will apply with these changes

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

If you think the mosad wants you dead since a long time then you are either
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