[FFmpeg-cvslog] avcodec/ffwavesynth: Fix undefined overflow in wavesynth_synth_sample()

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Mon Nov 25 21:50:57 2019 +0100| [97de004ad9952e068a5b614b302b200fbdd171e2] | committer: Michael Niedermayer

avcodec/ffwavesynth: Fix undefined overflow in wavesynth_synth_sample()

Fixes: signed integer overflow: 2147464192 + 21176 cannot be represented in type 'int'
Fixes: 19042/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFWAVESYNTH_fuzzer-5719828090585088

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit fa47f6412dbf93b4865adf8c66618906a3274330)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=97de004ad9952e068a5b614b302b200fbdd171e2
---

 libavcodec/ffwavesynth.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/ffwavesynth.c b/libavcodec/ffwavesynth.c
index 349b45534d..b9c63abb8d 100644
--- a/libavcodec/ffwavesynth.c
+++ b/libavcodec/ffwavesynth.c
@@ -350,7 +350,8 @@ fail:
 static void wavesynth_synth_sample(struct wavesynth_context *ws, int64_t ts,
                                    int32_t *channels)
 {
-    int32_t amp, val, *cv;
+    int32_t amp, *cv;
+    unsigned val;
     struct ws_interval *in;
     int i, *last, pink;
     uint32_t c, all_ch = 0;