[FFmpeg-devel] [PATCH] avcodec/dirac_vlc: Fix integer overflow in ff_dirac_golomb_read_32bit()

[Michael Niedermayer]

On Sat, Apr 25, 2020 at 12:29:15AM +0200, Lynne wrote:
> Apr 24, 2020, 23:04 by michael at niedermayer.cc:
> 
> > Fixes: left shift of 1073741824 by 1 places cannot be represented in type 'int32_t' (aka 'int')
> > Fixes: 21245/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5683334274613248
> >
> > 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/dirac_vlc.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/dirac_vlc.c b/libavcodec/dirac_vlc.c
> > index fbe28017bc..6d53078fc0 100644
> > --- a/libavcodec/dirac_vlc.c
> > +++ b/libavcodec/dirac_vlc.c
> > @@ -1115,7 +1115,7 @@ int ff_dirac_golomb_read_32bit(const uint8_t *buf, int bytes,
> >  {
> >  LUTState lut = ff_dirac_golomb_lut[*buf++];
> >  int32_t *dst = (int32_t *)_dst, *last = dst + coeffs;
> > -    int32_t val = 0;
> > +    uint32_t val = 0;
> >  
> >  for (int i = 1; i < bytes; i++)
> >  PROCESS_VALS;
> > -- 
> > 2.17.1
> >
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> >
> 
> LGTM.
> You should change the same variable in ff_dirac_golomb_read_16bit to a uint16_t too, to be safe.

will apply with that change

thx

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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