From 85f5aaa15fda09e8c01880d4ec622dd33c7b3636 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Mon, 13 Jun 2022 02:01:20 +0200
Subject: [PATCH] avcodec/bink: disallow odd positioned scaled blocks
Fixes: out of array access
Fixes: 47911/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BINK_fuzzer-6194020855971840
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit b14104a6376cd774b08cbe5fda56b34320a41b2e)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
libavcodec/bink.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavcodec/bink.c b/libavcodec/bink.c
index 5efd24e9c3..c7d76d1d14 100644
--- a/libavcodec/bink.c
+++ b/libavcodec/bink.c
@@ -1086,7 +1086,7 @@ static int bink_decode_plane(BinkContext *c, AVFrame *frame, GetBitContext *gb,
for (bx = 0; bx < bw; bx++, dst += 8, prev += 8) {
blk = get_value(c, BINK_SRC_BLOCK_TYPES);
// 16x16 block type on odd line means part of the already decoded block, so skip it
- if ((by & 1) && blk == SCALED_BLOCK) {
+ if (((by & 1) || (bx & 1)) && blk == SCALED_BLOCK) {
bx++;
dst += 8;
prev += 8;