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

[Michael Niedermayer]

On Fri, Jul 19, 2019 at 03:36:43PM +0200, Paul B Mahol wrote:
> On 7/19/19, Michael Niedermayer <michael at niedermayer.cc> wrote:
> > 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
> >> >
> >> > _______________________________________________
> >> > ffmpeg-devel mailing list
> >> > ffmpeg-devel at ffmpeg.org
> >> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >> >
> >> > To unsubscribe, visit link above, or email
> >> > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> >>
> >> 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 ...
> 
> I'm on vacation, so when I get back I will give you some files.

ok, ill wait, no hurry, enjoy your vacation!

Thanks!

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

Frequently ignored answer#1 FFmpeg bugs should be sent to our bugtracker. User
questions about the command line tools should be sent to the ffmpeg-user ML.
And questions about how to use libav* should be sent to the libav-user ML.
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