[FFmpeg-devel] Re: [PATCH 5/5] avcodec/osq: Fix 32bit sample overflow

[Michael Niedermayer via ffmpeg-devel <ffmpeg-devel@ffmpeg.org>]

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On Mon, Jul 14, 2025 at 08:58:52PM +0200, Michael Niedermayer wrote:
> On Sun, Jul 13, 2025 at 07:37:06PM +0200, Andreas Rheinhardt wrote:
> > Michael Niedermayer:
> > > Fixes: signed integer overflow: 2147483565 + 128 cannot be represented in type 'int'
> > > Fixes: 428055715/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_OSQ_fuzzer-6358069900804096
> > > 
> > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > > Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
> > > ---
> > >  libavcodec/osq.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/libavcodec/osq.c b/libavcodec/osq.c
> > > index 76090aa8d07..1d99ab32451 100644
> > > --- a/libavcodec/osq.c
> > > +++ b/libavcodec/osq.c
> > > @@ -390,7 +390,7 @@ static int osq_decode_block(AVCodecContext *avctx, AVFrame *frame)
> > >              int32_t *src = s->decode_buffer[ch] + OFFSET;
> > >  
> > >              for (int n = 0; n < nb_samples; n++)
> > > -                dst[n] = av_clip_uint8(src[n] + 0x80);
> > > +                dst[n] = av_clip_uint8(src[n] + 0x80ll);
> > >          }
> > >          break;
> > >      case AV_SAMPLE_FMT_S16P:
> > 
> > Why do you use a 64bit intermediate instead of simply using unsigned
> > like we do everywhere else?
> 
> we can use an unsigned but the intend was to clip obviously
> and while the C code uses 64bit the optimized asm should not
> need that
> 
> Iam happy to change it to unsigned if you prefer

no reply, will apply

thx

[...]

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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I am the wisest man alive, for I know one thing, and that is that I know
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