[FFmpeg-cvslog] avcodec/huffyuvdec: Check that slice height is non negative.

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Jan  6 11:15:35 2019 +0100| [96e495082aedc4fcf444e2c7ef301867ba3e0b1f] | committer: Michael Niedermayer

avcodec/huffyuvdec: Check that slice height is non negative.

Fixes: out of array access
Fixes: 12381/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5705474280783872
Fixes: 12384/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5725303345774592
Fixes: 12389/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5704033050820608
Fixes: 12391/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HYMT_fuzzer-5707284146028544

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=96e495082aedc4fcf444e2c7ef301867ba3e0b1f
---

 libavcodec/huffyuvdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/huffyuvdec.c b/libavcodec/huffyuvdec.c
index 4e00692631..dfe3585e6e 100644
--- a/libavcodec/huffyuvdec.c
+++ b/libavcodec/huffyuvdec.c
@@ -1254,7 +1254,7 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
         slices_info_offset = AV_RL32(avpkt->data + buf_size - 4);
         slice_height = AV_RL32(avpkt->data + buf_size - 8);
         nb_slices = AV_RL32(avpkt->data + buf_size - 12);
-        if (nb_slices * 8LL + slices_info_offset > buf_size - 16)
+        if (nb_slices * 8LL + slices_info_offset > buf_size - 16 || slice_height <= 0)
             return AVERROR_INVALIDDATA;
     } else {
         slice_height = height;