[FFmpeg-devel] [PATCH] avcodec/pngdec: Check for fctl after idat
Michael Niedermayer
michael at niedermayer.cc
Thu Jun 25 21:13:08 EEST 2020
Fixes: out of array access
Fixes: 23554/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APNG_fuzzer-4796622520451072.fuzz
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 | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index ff3882a58d..647e7f0a74 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -984,6 +984,11 @@ static int decode_fctl_chunk(AVCodecContext *avctx, PNGDecContext *s,
return AVERROR_INVALIDDATA;
}
+ if (s->pic_state & PNG_IDAT) {
+ av_log(avctx, AV_LOG_ERROR, "fctl after IDAT\n");
+ return AVERROR_INVALIDDATA;
+ }
+
s->last_w = s->cur_w;
s->last_h = s->cur_h;
s->last_x_offset = s->x_offset;
--
2.17.1
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