[FFmpeg-devel] [PATCH 1/2] avcodec/pngdec: consider chunk size in minimal size check
Michael Niedermayer
michael at niedermayer.cc
Mon Jul 22 02:25:27 EEST 2019
assuming each block contains an empty chunk there has to be at least 8 bytes extra.
Fixes: 15327/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_LSCR_fuzzer-5676669303521280
Fixes: Timeout (11->5sec)
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
libavcodec/pngdec.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index bf5a5191cc..cad5796545 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -1547,7 +1547,7 @@ 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)
+ if (bytestream2_get_bytes_left(gb) < 2 + nb_blocks * (12 + 8))
return AVERROR_INVALIDDATA;
if (s->last_picture.f->data[0]) {
--
2.22.0
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