From cc548ea7a60355e15ed78431a55a896db074aa11 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 12 Jan 2013 03:40:54 +0100 Subject: [PATCH] vc1dec: ensure cbpcy_vlc has been set before decoding a frame. Fixes null pointer dereference Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libavcodec/vc1dec.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c index fa25161d75..7be1c8cbab 100644 --- a/libavcodec/vc1dec.c +++ b/libavcodec/vc1dec.c @@ -5711,6 +5711,10 @@ static int vc1_decode_frame(AVCodecContext *avctx, void *data, av_log(v->s.avctx, AV_LOG_ERROR, "end mb y %d %d invalid\n", s->end_mb_y, s->start_mb_y); continue; } + if (!v->p_frame_skipped && s->pict_type != AV_PICTURE_TYPE_I && !v->cbpcy_vlc) { + av_log(v->s.avctx, AV_LOG_ERROR, "missing cbpcy_vlc\n"); + continue; + } ff_vc1_decode_blocks(v); if (i != n_slices) s->gb = slices[i].gb;