From b0c14b02b0570a2edd7054bf7dd6b6e9b00e5858 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 24 Jun 2018 19:23:02 +0200 Subject: [PATCH] avcodec/escape124: Check buf_size against num_superblocks Fixes: Timeout Fixes: 8722/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ESCAPE124_fuzzer-4843268402577408 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 6677c98626489edfdb4b49b4f66ca91867768a9f) Signed-off-by: Michael Niedermayer --- libavcodec/escape124.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/libavcodec/escape124.c b/libavcodec/escape124.c index c3174ce6ef..186f0cb8af 100644 --- a/libavcodec/escape124.c +++ b/libavcodec/escape124.c @@ -221,7 +221,11 @@ static int escape124_decode_frame(AVCodecContext *avctx, // This call also guards the potential depth reads for the // codebook unpacking. - if (get_bits_left(&gb) < 64) + // Check if the amount we will read minimally is available on input. + // The 64 represent the immedeatly next 2 frame_* elements read, the 23/4320 + // represent a lower bound of the space needed for skiped superblocks. Non + // skipped SBs need more space. + if (get_bits_left(&gb) < 64 + s->num_superblocks * 23LL / 4320) return -1; frame_flags = get_bits_long(&gb, 32);