From 2cb1f797350875ec45cb20d59dc0684fcbac20fc Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 4 Aug 2019 08:32:58 +0200 Subject: [PATCH] avcodec/vc1_block: Check get_vlc2() return before use Fixes: index -1 out of bounds for type 'const uint8_t [185][2]' Fixes: 15720/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MSS2_fuzzer-5666071933091840 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/vc1_block.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/libavcodec/vc1_block.c b/libavcodec/vc1_block.c index eda0b28964..97c873f138 100644 --- a/libavcodec/vc1_block.c +++ b/libavcodec/vc1_block.c @@ -526,6 +526,8 @@ static int vc1_decode_ac_coeff(VC1Context *v, int *last, int *skip, int escape = decode210(gb); if (escape != 2) { index = get_vlc2(gb, ff_vc1_ac_coeff_table[codingset].table, AC_VLC_BITS, 3); + if (index < 0) + return AVERROR_INVALIDDATA; run = vc1_index_decode_table[codingset][index][0]; level = vc1_index_decode_table[codingset][index][1]; lst = index >= vc1_last_decode_table[codingset];