[FFmpeg-cvslog] avcodec/ituh263dec: Fix runtime error: left shift of negative value -22

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Feb 21 17:32:56 2017 +0100| [631f7484918a9e7260377c3cea878be708609e64] | committer: Michael Niedermayer

avcodec/ituh263dec: Fix runtime error: left shift of negative value -22

Fixes: 639/clusterfuzz-testcase-5143866241974272

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=631f7484918a9e7260377c3cea878be708609e64
---

 libavcodec/ituh263dec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/ituh263dec.c b/libavcodec/ituh263dec.c
index 73aaa1d..9a2c8e6 100644
--- a/libavcodec/ituh263dec.c
+++ b/libavcodec/ituh263dec.c
@@ -524,7 +524,7 @@ retry:
                     }else{
                         level = SHOW_UBITS(re, &s->gb, 5);
                         SKIP_CACHE(re, &s->gb, 5);
-                        level |= SHOW_SBITS(re, &s->gb, 6)<<5;
+                        level |= SHOW_SBITS(re, &s->gb, 6) * (1<<5);
                         SKIP_COUNTER(re, &s->gb, 5 + 6);
                     }
                 }