[FFmpeg-devel] [PATCH 1/2] avcodec/pictordec: Optimize more odd cases for picmemset()

[Michael Niedermayer]

On Wed, Sep 01, 2021 at 09:50:20AM +1000, Peter Ross wrote:
> On Tue, Aug 31, 2021 at 08:33:41PM +0200, Michael Niedermayer wrote:
> > Fixes: Timeout
> > Fixes: 36875/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PICTOR_fuzzer-4842960888922112
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavcodec/pictordec.c | 5 ++---
> >  1 file changed, 2 insertions(+), 3 deletions(-)
> > 
> > diff --git a/libavcodec/pictordec.c b/libavcodec/pictordec.c
> > index c37c5e7106..c7b3a335d3 100644
> > --- a/libavcodec/pictordec.c
> > +++ b/libavcodec/pictordec.c
> > @@ -89,8 +89,7 @@ static void picmemset(PicContext *s, AVFrame *frame, unsigned value, int run,
> >                  d = frame->data[0] + yl * frame->linesize[0];
> >                  if (s->nb_planes == 1 &&
> >                      run*pixels_per_value >= s->width &&
> > -                    pixels_per_value < s->width &&
> > -                    s->width % pixels_per_value == 0
> > +                    pixels_per_value < (s->width / pixels_per_value * pixels_per_value)
> >                      ) {
> >                      for (; xl < pixels_per_value; xl ++) {
> >                          j = (j < bits_per_plane ? 8 : j) - bits_per_plane;
> > @@ -98,7 +97,7 @@ static void picmemset(PicContext *s, AVFrame *frame, unsigned value, int run,
> >                      }
> >                      av_memcpy_backptr(d+xl, pixels_per_value, s->width - xl);
> >                      run -= s->width / pixels_per_value;
> > -                    xl = s->width;
> > +                    xl = s->width / pixels_per_value * pixels_per_value;
> >                  }
> >              }
> >          }
> > -- 
> > 2.17.1
> 
> i have tested this against variety of samples. please apply.

will apply

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Good people do not need laws to tell them to act responsibly, while bad
people will find a way around the laws. -- Plato
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