[FFmpeg-devel] [PATCH 7/8] avcodec/vc1_block: Fix undefined behavior in ac prediction rescaling

[Michael Niedermayer]

On Thu, Oct 31, 2019 at 06:58:29PM +0100, Michael Niedermayer wrote:
> The intermediates are required to fit in 12bit (8.1.3.9 Coefficient Scaling)
> See SMPTE 421M-2006 and Amendment 1-2007
> 
> Fixes: signed integer overflow: -20691 * 262144 cannot be represented in type 'int'
> Fixes: 18479/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC1_fuzzer-5128912371187712
> 
> 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/vc1_block.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

will apply

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

I have often repented speaking, but never of holding my tongue.
-- Xenocrates
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