From c9415e815a996d287850a3572ce2c1d663b9f657 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 22 Jun 2019 14:21:43 +0200 Subject: [PATCH] avcodec/vc1_block: Fix invalid shifts in vc1_decode_i_blocks() Fixes: left shift of negative value -9 Fixes: 15299/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MSS2_fuzzer-5660922678345728 Fixes: 15557/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC1IMAGE_fuzzer-5673351911047168 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/vc1_block.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/vc1_block.c b/libavcodec/vc1_block.c index 7883e4f19c..94184b0873 100644 --- a/libavcodec/vc1_block.c +++ b/libavcodec/vc1_block.c @@ -2602,13 +2602,13 @@ static void vc1_decode_i_blocks(VC1Context *v) if (v->rangeredfrm) for (k = 0; k < 6; k++) for (j = 0; j < 64; j++) - v->block[v->cur_blk_idx][block_map[k]][j] <<= 1; + v->block[v->cur_blk_idx][block_map[k]][j] *= 2; vc1_put_blocks_clamped(v, 1); } else { if (v->rangeredfrm) for (k = 0; k < 6; k++) for (j = 0; j < 64; j++) - v->block[v->cur_blk_idx][block_map[k]][j] = (v->block[v->cur_blk_idx][block_map[k]][j] - 64) << 1; + v->block[v->cur_blk_idx][block_map[k]][j] = (v->block[v->cur_blk_idx][block_map[k]][j] - 64) * 2; vc1_put_blocks_clamped(v, 0); }