[FFmpeg-devel] [PATCH 4/9] avformat/wtvdec: Improve size overflow checks in parse_chunks()

[Michael Niedermayer]

On Wed, Apr 21, 2021 at 06:28:41PM +1000, Peter Ross wrote:
> On Mon, Apr 19, 2021 at 08:23:41PM +0200, Michael Niedermayer wrote:
> > Fixes: signed integer overflow: 32 + 2147483647 cannot be represented in type 'int
> > Fixes: 32967/clusterfuzz-testcase-minimized-ffmpeg_dem_WTV_fuzzer-5132856218222592
> > 
> > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavformat/wtvdec.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/libavformat/wtvdec.c b/libavformat/wtvdec.c
> > index 44ca86d517..2f1b192cea 100644
> > --- a/libavformat/wtvdec.c
> > +++ b/libavformat/wtvdec.c
> > @@ -809,7 +809,7 @@ static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_p
> >                  avio_skip(pb, 12);
> >                  ff_get_guid(pb, &formattype);
> >                  size = avio_rl32(pb);
> > -                if (size < 0 || size > INT_MAX - 92)
> > +                if (size < 0 || size > INT_MAX - 92 - consumed)
> >                      return AVERROR_INVALIDDATA;
> >                  parse_media_type(s, 0, sid, mediatype, subtype, formattype, size);
> >                  consumed += 92 + size;
> > @@ -825,7 +825,7 @@ static int parse_chunks(AVFormatContext *s, int mode, int64_t seekts, int *len_p
> >                  avio_skip(pb, 12);
> >                  ff_get_guid(pb, &formattype);
> >                  size = avio_rl32(pb);
> > -                if (size < 0 || size > INT_MAX - 76)
> > +                if (size < 0 || size > INT_MAX - 76 - consumed)
> >                      return AVERROR_INVALIDDATA;
> >                  parse_media_type(s, s->streams[stream_index], sid, mediatype, subtype, formattype, size);
> >                  consumed += 76 + size;
> > -- 
> 
> please apply

will apply

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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