[FFmpeg-devel] [PATCH 2/3] avcodec/siren: Check available bits at frame start

[Michael Niedermayer]

On Wed, Sep 29, 2021 at 12:54:02PM -0300, James Almer wrote:
> On 9/29/2021 12:31 PM, Michael Niedermayer wrote:
> > On Tue, Sep 28, 2021 at 10:19:48PM -0300, James Almer wrote:
> > > On 9/28/2021 7:28 PM, Michael Niedermayer wrote:
> > > > Fixes: Timeout
> > > > Fixes: 39089/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MSNSIREN_fuzzer-6677219854909440
> > > > 
> > > > Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > > > Suggested-by: James Almer <jamrial at gmail.com>
> > > > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > > > ---
> > > >    libavcodec/siren.c | 6 +++++-
> > > >    1 file changed, 5 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/libavcodec/siren.c b/libavcodec/siren.c
> > > > index 7f084172a4c..8c9628e2d8e 100644
> > > > --- a/libavcodec/siren.c
> > > > +++ b/libavcodec/siren.c
> > > > @@ -447,6 +447,8 @@ static int decode_envelope(SirenContext *s, GetBitContext *gb,
> > > >            int index = 0;
> > > >            do {
> > > > +            if (get_bits_left(gb) < 4)
> > > 
> > > If the idea is that there will be enough bits to read rate_control after
> > > this function returns, then this should also take into account the
> > > get_bits1() below.
> > 
> > Do you suggest that this is merged with 3/3 or do you suggest something else ?
> 
> I was thinking making this a < 5 check, so it's guaranteed there's one for
> index inside this do while loop plus four for rate_control after returning
> from this function, but i hadn't looked at the 3/3 patch when i wrote that,
> and now i see it actually adds a consideration for that.
> 
> LGTM then. And no opinion about squashing them. Do as you prefer.

will apply seperatly

thx

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

Concerning the gods, I have no means of knowing whether they exist or not
or of what sort they may be, because of the obscurity of the subject, and
the brevity of human life -- Protagoras
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
URL: <https://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20210929/79be89c0/attachment.sig>