[FFmpeg-cvslog] avcodec/h264_slice: Clear ref_counts on redundant slices

[Michael Niedermayer]

ffmpeg | branch: release/3.2 | Michael Niedermayer <michael at niedermayer.cc> | Wed Feb  8 17:55:41 2017 +0100| [63637e457c4cc32b6e720206f48f6d354adda190] | committer: Michael Niedermayer

avcodec/h264_slice: Clear ref_counts on redundant slices

Fixes reading freed memory
Fixes: 568/clusterfuzz-testcase-6107186067406848

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit c03029a835949fc0e68b4c6558ebcdc3ae137087)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=63637e457c4cc32b6e720206f48f6d354adda190
---

 libavcodec/h264_slice.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index 25a5890..8aaa370 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -1771,8 +1771,10 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl,
         return ret;
 
     // discard redundant pictures
-    if (sl->redundant_pic_count > 0)
+    if (sl->redundant_pic_count > 0) {
+        sl->ref_count[0] = sl->ref_count[1] = 0;
         return 0;
+    }
 
     if (sl->first_mb_addr == 0 || !h->current_slice) {
         if (h->setup_finished) {