From 85d51d8e327c666ac963acf25cf6a6763e6c6671 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 1 Feb 2014 05:34:25 +0100 Subject: [PATCH] avcodec/vc1dec: field pictures with direct mode MBs, followed by frame pictures are not supported This case could occur when cuting and concatenating bitstreams Fixes out of array read Fixes: asan_heap-oob_1b33fdd_2849_cov_478905890_SA10143.vc1 Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libavcodec/vc1dec.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libavcodec/vc1dec.c b/libavcodec/vc1dec.c index b273efb5e3..5e66434d24 100644 --- a/libavcodec/vc1dec.c +++ b/libavcodec/vc1dec.c @@ -4342,6 +4342,10 @@ static void vc1_decode_b_mb_intfi(VC1Context *v) if (bmvtype == BMV_TYPE_DIRECT) { dmv_x[0] = dmv_y[0] = pred_flag[0] = 0; dmv_x[1] = dmv_y[1] = pred_flag[0] = 0; + if (!s->next_picture_ptr->field_picture) { + av_log(s->avctx, AV_LOG_ERROR, "Mixed field/frame direct mode not supported\n"); + return; + } } vc1_pred_b_mv_intfi(v, 0, dmv_x, dmv_y, 1, pred_flag); vc1_b_mc(v, dmv_x, dmv_y, (bmvtype == BMV_TYPE_DIRECT), bmvtype); @@ -6014,6 +6018,7 @@ static int vc1_decode_frame(AVCodecContext *avctx, void *data, goto err; } + v->s.current_picture_ptr->field_picture = v->field_mode; v->s.current_picture_ptr->f.interlaced_frame = (v->fcm != PROGRESSIVE); v->s.current_picture_ptr->f.top_field_first = v->tff;