[FFmpeg-cvslog] avcodec/amrwbdec: Fix runtime error: left shift of negative value -1

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Mar 11 03:55:39 2017 +0100| [44e2105189ac66637f34c764febc349238250b1d] | committer: Michael Niedermayer

avcodec/amrwbdec: Fix  runtime error: left shift of negative value -1

Fixes: 763/clusterfuzz-testcase-6007567320875008

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=44e2105189ac66637f34c764febc349238250b1d
---

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

diff --git a/libavcodec/amrwbdec.c b/libavcodec/amrwbdec.c
index 999bfb9..57aed87 100644
--- a/libavcodec/amrwbdec.c
+++ b/libavcodec/amrwbdec.c
@@ -262,7 +262,7 @@ static void decode_pitch_lag_high(int *lag_int, int *lag_frac, int pitch_index,
             *lag_frac = pitch_index - (*lag_int << 2) + 136;
         } else if (pitch_index < 440) {
             *lag_int  = (pitch_index + 257 - 376) >> 1;
-            *lag_frac = (pitch_index - (*lag_int << 1) + 256 - 376) << 1;
+            *lag_frac = (pitch_index - (*lag_int << 1) + 256 - 376) * 2;
             /* the actual resolution is 1/2 but expressed as 1/4 */
         } else {
             *lag_int  = pitch_index - 280;