Hi, On Tue, May 9, 2017 at 9:24 PM, Michael Niedermayer <mich...@niedermayer.cc> wrote:
> On Tue, May 09, 2017 at 09:08:08PM -0400, Ronald S. Bultje wrote: > > Hi, > > > > On Tue, May 9, 2017 at 8:37 PM, Michael Niedermayer > <mich...@niedermayer.cc> > > wrote: > > > > > Fixes: out of array access > > > Fixes: 1434/clusterfuzz-testcase-minimized-6314998085189632 > > > Fixes: 1435/clusterfuzz-testcase-minimized-6483783723253760 > > > > > > Found-by: continuous fuzzing process https://github.com/google/oss- > > > fuzz/tree/master/targets/ffmpeg > > > Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > > > --- > > > libavcodec/webp.c | 9 +++++++-- > > > 1 file changed, 7 insertions(+), 2 deletions(-) > > > > > > diff --git a/libavcodec/webp.c b/libavcodec/webp.c > > > index 16c3ae2662..23ed4bc26f 100644 > > > --- a/libavcodec/webp.c > > > +++ b/libavcodec/webp.c > > > @@ -1330,12 +1330,17 @@ static int vp8_lossy_decode_frame( > AVCodecContext > > > *avctx, AVFrame *p, > > > WebPContext *s = avctx->priv_data; > > > AVPacket pkt; > > > int ret; > > > + enum AVPixelFormat wanted_pix_fmt = s->has_alpha ? > > > AV_PIX_FMT_YUVA420P : AV_PIX_FMT_YUV420P; > > > + > > > + if (s->initialized && wanted_pix_fmt != avctx->pix_fmt) { > > > + ff_vp8_decode_free(avctx); > > > + s->initialized = 0; > > > + } > > > > > > if (!s->initialized) { > > > ff_vp8_decode_init(avctx); > > > s->initialized = 1; > > > - if (s->has_alpha) > > > - avctx->pix_fmt = AV_PIX_FMT_YUVA420P; > > > + avctx->pix_fmt = wanted_pix_fmt; > > > } > > > s->lossless = 0; > > > > > > What is the out of array access? webp is intra only and the only thing > that > > is initialized with memory in that call is reference frames. What's going > > on here? > > webp uses the same context as VP8, and it changes the pixel format > as it needs. Vp8 doesnt work if its format is changed under its feet > > the reinit seemed reasonable cleanish to handle it. There are a few > other ways the same can be achived What is the out of array access? Ronald _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
