[FFmpeg-cvslog] avcodec/g723_1dec: Fix overflow in shift

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Sep 27 17:53:35 2019 +0200| [07732f12a43ac3048e44c086c9a8c811452ba31c] | committer: Michael Niedermayer

avcodec/g723_1dec: Fix overflow in shift

Fixes: shift exponent 1008 is too large for 32-bit type 'int'
Fixes: 17700/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_G723_1_fuzzer-5707633436131328

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=07732f12a43ac3048e44c086c9a8c811452ba31c
---

 libavcodec/g723_1dec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/g723_1dec.c b/libavcodec/g723_1dec.c
index d1faf92c39..a7bf528470 100644
--- a/libavcodec/g723_1dec.c
+++ b/libavcodec/g723_1dec.c
@@ -678,6 +678,8 @@ static int estimate_sid_gain(G723_1_ChannelContext *p)
             else                 t = INT32_MAX;
         } else
             t = p->sid_gain << shift;
+    } else if(shift < -31) {
+        t = (p->sid_gain < 0) ? -1 : 0;
     }else
         t = p->sid_gain >> -shift;
     x = av_clipl_int32(t * (int64_t)cng_filt[0] >> 16);