On Sun, May 28, 2023 at 08:53:49PM +0200, Marton Balint wrote:
> 
> 
> On Thu, 25 May 2023, Michael Niedermayer wrote:
> 
> > Fixes: signed integer overflow: -9223372036854775808 - 2082844800 cannot be represented in type 'long'
> > Fixes: 58384/clusterfuzz-testcase-minimized-ffmpeg_dem_MOV_fuzzer-6428383700713472
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> > ---
> > libavformat/mov.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> > 
> > diff --git a/libavformat/mov.c b/libavformat/mov.c
> > index 9fdeef057e..3e2c4bc10d 100644
> > --- a/libavformat/mov.c
> > +++ b/libavformat/mov.c
> > @@ -1530,6 +1530,10 @@ static void mov_metadata_creation_time(MOVContext *c, AVIOContext *pb, AVDiction
> >         }
> >     }
> >     if (time) {
> > +        if (time < INT64_MIN + 2082844800) {
> > +            av_log(c->fc, AV_LOG_DEBUG, "creation_time predates big bang\n");
> > +            return;
> > +        }
> 
> Actually creation_time is unsigned, so it cannot be negative. I suggest you
> simply reject everyting less than 0 here. You should also move the check to
> the version == 1 case, because only that can read a "negative" value.

ok will apply with these changes

thx

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

Asymptotically faster algorithms should always be preferred if you have
asymptotical amounts of data