[FFmpeg-devel] [PATCH] Fix integer overflow in mov_read_packet().

[Dale Curtis]

On Fri, Nov 24, 2023 at 3:38 PM Michael Niedermayer <michael at niedermayer.cc>
wrote:

> On Wed, Nov 22, 2023 at 02:20:59PM -0800, Dale Curtis wrote:
> > Fixes https://crbug.com/1499669:
>
> > runtime error: signed integer overflow: 9223372036853334272 + 1375731456
>
> this looks a bit close to AV_NOPTS_VALUE but its not actually that close
>

Yes I originally thought the same thing!


>
>
> > cannot be represented in type 'int64_t' (aka 'long')
> >
> > Signed-off-by: Dale Curtis <dalecurtis at chromium.org>
> > ---
> >  libavformat/mov.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/libavformat/mov.c b/libavformat/mov.c
> > index 93f202d204..425ddc6849 100644
> > --- a/libavformat/mov.c
> > +++ b/libavformat/mov.c
> > @@ -9023,7 +9023,7 @@ static int mov_read_packet(AVFormatContext *s,
> AVPacket *pkt)
> >          pkt->flags |= AV_PKT_FLAG_DISCARD;
> >      }
> >      if (sc->ctts_data && sc->ctts_index < sc->ctts_count) {
> > -        pkt->pts = pkt->dts + sc->dts_shift +
> sc->ctts_data[sc->ctts_index].duration;
> > +        pkt->pts = av_sat_add64(pkt->dts, av_sat_add64(sc->dts_shift,
> sc->ctts_data[sc->ctts_index].duration));
> >          /* update ctts context */
> >          sc->ctts_sample++;
> >          if (sc->ctts_index < sc->ctts_count &&
>
> This is probably ok
> alternatively pts could be set to AV_NOPTS_VALUE if its unrepresentable
>

I defer to you. Either is fine with me. Let me know if you'd like me to
change it.


>
> thx
>
> [...]
>
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> Many things microsoft did are stupid, but not doing something just because
> microsoft did it is even more stupid. If everything ms did were stupid they
> would be bankrupt already.
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