From 2224159c787ed19a3cd2e061bc00af125c9c2cef Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 14 Dec 2013 17:55:25 +0100 Subject: [PATCH] avcodec/vc1: fix DIFF2/NORM2 with width<=16 Fixes read of uninitialized memory Fixes msan_uninit-mem_7f785da000e8_585_480i30__codec_WVC1__mode_2__framerate_29.970__type_2__preproc_17.wmv Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer --- libavcodec/vc1.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c index f20b946be6..6557724954 100644 --- a/libavcodec/vc1.c +++ b/libavcodec/vc1.c @@ -122,12 +122,16 @@ static int bitplane_decoding(uint8_t* data, int *raw_flag, VC1Context *v) case IMODE_NORM2: if ((height * width) & 1) { *planep++ = get_bits1(gb); - offset = 1; + y = offset = 1; + if (offset == width) { + offset = 0; + planep += stride - width; + } } else - offset = 0; + y = offset = 0; // decode bitplane as one long line - for (y = offset; y < height * width; y += 2) { + for (; y < height * width; y += 2) { code = get_vlc2(gb, ff_vc1_norm2_vlc.table, VC1_NORM2_VLC_BITS, 1); *planep++ = code & 1; offset++;