From e78b0f83748f92ea9e93b21c36082e0dd04d7cb1 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 5 Jun 2019 12:18:54 +0200 Subject: [PATCH] avcodec/bitstream: Check for integer code truncation in build_table() Fixes: out of array read Fixes: 14563/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AGM_fuzzer-5646451545210880 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/bitstream.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/bitstream.c b/libavcodec/bitstream.c index 8762e5f4b2..590b490527 100644 --- a/libavcodec/bitstream.c +++ b/libavcodec/bitstream.c @@ -226,6 +226,10 @@ static int build_table(VLC *vlc, int table_nb_bits, int nb_codes, /* note: realloc has been done, so reload tables */ table = (volatile VLC_TYPE (*)[2])&vlc->table[table_index]; table[j][0] = index; //code + if (table[j][0] != index) { + avpriv_request_sample(NULL, "strange codes"); + return AVERROR_PATCHWELCOME; + } i = k-1; } }