[FFmpeg-cvslog] avcodec/mpeg_er: Clear mcsel in mpeg_er_decode_mb()

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Mon Oct  9 00:32:30 2017 +0200| [0d9baa6d16cc84a12f0c73af383c5242a3e4c451] | committer: Michael Niedermayer

avcodec/mpeg_er: Clear mcsel in mpeg_er_decode_mb()

Fixes out of array read
Should fix: 3516/clusterfuzz-testcase-minimized-4608518562775040 (not reprodoceable)

Found-by: Insu Yun, Georgia Tech.
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 127a362630e11fe724e2e63fc871791fdcbcfa64)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0d9baa6d16cc84a12f0c73af383c5242a3e4c451
---

 libavcodec/mpeg_er.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libavcodec/mpeg_er.c b/libavcodec/mpeg_er.c
index dd87ae9cc9..9bd269c440 100644
--- a/libavcodec/mpeg_er.c
+++ b/libavcodec/mpeg_er.c
@@ -71,6 +71,7 @@ static void mpeg_er_decode_mb(void *opaque, int ref, int mv_dir, int mv_type,
     s->mb_skipped = mb_skipped;
     s->mb_x       = mb_x;
     s->mb_y       = mb_y;
+    s->mcsel      = 0;
     memcpy(s->mv, mv, sizeof(*mv));
 
     ff_init_block_index(s);