From f05cd37d51dfcc7fc30d2cc1b1a0cc13bd527cb3 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 11 May 2017 18:39:33 +0200 Subject: [PATCH] avcodec/cllc: Check num_bits Fixes: runtime error: shift exponent -2 is negative Fixes: 1479/clusterfuzz-testcase-minimized-6638493360979968 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 2bfd0a97587d26c0c39413a6291ccc66e4a928d0) Signed-off-by: Michael Niedermayer --- libavcodec/cllc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/libavcodec/cllc.c b/libavcodec/cllc.c index 386b2f0ed2..24fa168e36 100644 --- a/libavcodec/cllc.c +++ b/libavcodec/cllc.c @@ -55,6 +55,13 @@ static int read_code_table(CLLCContext *ctx, GetBitContext *gb, VLC *vlc) num_lens = get_bits(gb, 5); + if (num_lens > VLC_BITS * VLC_DEPTH) { + vlc->table = NULL; + + av_log(ctx->avctx, AV_LOG_ERROR, "To long VLCs %d\n", num_lens); + return AVERROR_INVALIDDATA; + } + for (i = 0; i < num_lens; i++) { num_codes = get_bits(gb, 9); num_codes_sum += num_codes;