[FFmpeg-devel] [PATCH 5/6] avcodec/bonk: Avoid undefined overflow in quant

[Michael Niedermayer]

On Wed, Jan 11, 2023 at 10:06:44PM +0100, Paul B Mahol wrote:
> On 1/11/23, Michael Niedermayer <michael at niedermayer.cc> wrote:
> > Fixes: signed integer overflow: -2889074 * 2048 cannot be represented in
> > type 'int'
> > Fixes:
> > 51363/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BONK_fuzzer-5660734784143360
> > Fixes:
> > 48567/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BONK_fuzzer-6617680050520064
> > Fixes:
> > 48567/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BONK_fuzzer-6743951854141440
> >
> > No check is done for the overflow as this was rejected in last review, see
> > the ML
> >
> > Note: the 2nd and 3rd testcase was assigned by ossfuzz to a unrelated theora
> > issue (48567)
> >
> > 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/bonk.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/bonk.c b/libavcodec/bonk.c
> > index 5d736b1563..9e176d5477 100644
> > --- a/libavcodec/bonk.c
> > +++ b/libavcodec/bonk.c
> > @@ -356,7 +356,7 @@ static int bonk_decode(AVCodecContext *avctx, AVFrame
> > *frame,
> >                  sample++;
> >              }
> >
> > -            sample[0] = predictor_calc_error(s->k, state, s->n_taps,
> > s->input_samples[i] * quant);
> > +            sample[0] = predictor_calc_error(s->k, state, s->n_taps,
> > s->input_samples[i] * (unsigned)quant);
> >              sample++;
> >          }
> >
> > --
> > 2.17.1
> >
> 
> LGTM

will apply

thx

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

Avoid a single point of failure, be that a person or equipment.
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