From 4fd74a2b104f3e67f251b67099f5855c386a55bd Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 27 Apr 2019 23:49:33 +0200 Subject: [PATCH] avcodec/pngdec: Check nb_blocks Fixes: Timeout (23sec -> 0.5sec) Fixes: 14329/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_LSCR_fuzzer-5679252923482112 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: Paul B Mahol Signed-off-by: Michael Niedermayer --- libavcodec/pngdec.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c index 6a681be29d..7fcf83e347 100644 --- a/libavcodec/pngdec.c +++ b/libavcodec/pngdec.c @@ -1541,6 +1541,8 @@ static int decode_frame_lscr(AVCodecContext *avctx, return ret; nb_blocks = bytestream2_get_le16(gb); + if (bytestream2_get_bytes_left(gb) < 2 + nb_blocks * 12) + return AVERROR_INVALIDDATA; if (s->last_picture.f->data[0]) { ret = av_frame_copy(frame, s->last_picture.f);