On Sun, Jun 23, 2019 at 06:33:02PM +1000, Peter Ross wrote:
> On Sun, Jun 23, 2019 at 12:30:54AM +0200, Michael Niedermayer wrote:
> > This checks the ham value much stricter and avoids hitting cases which 
> > cannot be reached
> > with data from the libavformat demuxer.
> > 
> > Fixes: out of array access
> > Fixes: 
> > 15320/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IFF_ILBM_fuzzer-5080476840099840
> > Fixes: 
> > 15423/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IFF_ILBM_fuzzer-5630765833912320
> > 
> > Found-by: continuous fuzzing process 
> > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc>
> > ---
> >  libavcodec/iff.c | 15 ++++++++++++---
> >  1 file changed, 12 insertions(+), 3 deletions(-)
> > 
> > diff --git a/libavcodec/iff.c b/libavcodec/iff.c
> > index b43bd507b3..b065bbe598 100644
> > --- a/libavcodec/iff.c
> > +++ b/libavcodec/iff.c
> > @@ -280,6 +280,18 @@ static int extract_header(AVCodecContext *const avctx,
> >          for (i = 0; i < 16; i++)
> >              s->tvdc[i] = bytestream_get_be16(&buf);
> >  
> > +        if (s->ham) {
> > +            if (s->bpp > 8) {
> > +                av_log(avctx, AV_LOG_ERROR, "Invalid number of hold bits 
> > for HAM: %u\n", s->ham);
> > +                s->ham = 0;
> > +                return AVERROR_INVALIDDATA;
> > +            } if (s->ham != (s->bpp > 6 ? 6 : 4)) {
> > +                av_log(avctx, AV_LOG_ERROR, "Invalid number of hold bits 
> > for HAM: %u, BPP: %u\n", s->ham, s->bpp);
> > +                s->ham = 0;
> > +                return AVERROR_INVALIDDATA;
> > +            }
> > +        }
> 
> i am curious why we need to reset ham = 0? otherwise patch okay.

That was just so as not to leave an invalid value in the context. It is
very likely not needed, I will remove it.


> 
> patch 1 and 3 okay.

will apply

thx


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

Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety -- Benjamin Franklin

Attachment: signature.asc
Description: PGP signature

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".

Reply via email to