[FFmpeg-devel] [PATCH 3/4] avcodec/dxv: Check op_offset in both directions

[Michael Niedermayer]

On Thu, Jun 27, 2019 at 09:32:44AM +0200, Paul B Mahol wrote:
> On 6/27/19, Michael Niedermayer <michael at niedermayer.cc> wrote:
> > Fixes: signed integer overflow: 61 + 2147483647 cannot be represented in
> > type 'int'
> > Fixes:
> > 15311/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DXV_fuzzer-5742552826773504
> >
> > 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/dxv.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/dxv.c b/libavcodec/dxv.c
> > index 5fd1844094..3506775560 100644
> > --- a/libavcodec/dxv.c
> > +++ b/libavcodec/dxv.c
> > @@ -745,7 +745,7 @@ static int dxv_decompress_cocg(DXVContext *ctx,
> > GetByteContext *gb,
> >      int skip0, skip1, oi0 = 0, oi1 = 0;
> >      int ret, state0 = 0, state1 = 0;
> >
> > -    if (op_offset < 12)
> > +    if (op_offset < 12 || op_offset - 12 > bytestream2_get_bytes_left(gb))
> >          return AVERROR_INVALIDDATA;
> >
> >      dst = tex_data;
> > --
> > 2.22.0
> >
> > _______________________________________________
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> >
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> 
> Make sure this does not break any files.

Do you have any specific files i should test ?

I of course cannot test every file on earth ...

Thanks

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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