From b2222721245cfbba2d3f6917f0ab316aaeb76db3 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 13 Jun 2022 02:01:20 +0200 Subject: 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 Signed-off-by: Michael Niedermayer (cherry picked from commit b14104a6376cd774b08cbe5fda56b34320a41b2e) Signed-off-by: Michael Niedermayer --- libavcodec/bink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavcodec/bink.c b/libavcodec/bink.c index ca10a0ce81..bc4fe7e163 100644 --- a/libavcodec/bink.c +++ b/libavcodec/bink.c @@ -1054,7 +1054,7 @@ 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; -- cgit v1.2.1