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

[Michael Niedermayer]

ffmpeg | branch: release/3.1 | Michael Niedermayer <michael at niedermayer.cc> | Wed Feb  8 17:55:41 2017 +0100| [d20200d3035eaca615ef3e2aeaba0017ae4e87a9] | 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=d20200d3035eaca615ef3e2aeaba0017ae4e87a9
---

 libavcodec/h264.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index a56f900..40c4ea1 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -1023,7 +1023,8 @@ again:
 #endif
                 } else
                     context_count++;
-            }
+            } else
+                sl->ref_count[0] = sl->ref_count[1] = 0;
             break;
         case NAL_DPA:
         case NAL_DPB: