[FFmpeg-cvslog] avcodec/g723_1dec: fix invalid shift with negative sid_gain

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Oct 26 21:56:03 2019 +0200| [1850c3feaa1c7b5b63a55c61075029fa59c84e66] | committer: Michael Niedermayer

avcodec/g723_1dec: fix invalid shift with negative sid_gain

Fixes: left shift of negative value -1
Fixes: 18395/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_G723_1_fuzzer-5710313034350592

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1850c3feaa1c7b5b63a55c61075029fa59c84e66
---

 libavcodec/g723_1dec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/g723_1dec.c b/libavcodec/g723_1dec.c
index a7bf528470..f601d31d00 100644
--- a/libavcodec/g723_1dec.c
+++ b/libavcodec/g723_1dec.c
@@ -677,7 +677,7 @@ static int estimate_sid_gain(G723_1_ChannelContext *p)
             if (p->sid_gain < 0) t = INT32_MIN;
             else                 t = INT32_MAX;
         } else
-            t = p->sid_gain << shift;
+            t = p->sid_gain * (1 << shift);
     } else if(shift < -31) {
         t = (p->sid_gain < 0) ? -1 : 0;
     }else