[FFmpeg-cvslog] avcodec/ffwavesynth: Fix integer overflows in pink noise addition

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Sep 30 00:35:15 2019 +0200| [7916b6863caec55d7e64758a1bfe436834f2faf6] | committer: Michael Niedermayer

avcodec/ffwavesynth: Fix integer overflows in pink noise addition

Fixes: signed integer overflow: -1795675744 + -1926578528 cannot be represented in type 'int'
Fixes: 17741/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFWAVESYNTH_fuzzer-5131336402075648

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=7916b6863caec55d7e64758a1bfe436834f2faf6
---

 libavcodec/ffwavesynth.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/ffwavesynth.c b/libavcodec/ffwavesynth.c
index 6736587e32..3a6a057964 100644
--- a/libavcodec/ffwavesynth.c
+++ b/libavcodec/ffwavesynth.c
@@ -377,7 +377,7 @@ static void wavesynth_synth_sample(struct wavesynth_context *ws, int64_t ts,
                 in->dphi += in->ddphi;
                 break;
             case WS_NOISE:
-                val = amp * pink;
+                val = amp * (unsigned)pink;
                 break;
             default:
                 val = 0;
@@ -385,7 +385,7 @@ static void wavesynth_synth_sample(struct wavesynth_context *ws, int64_t ts,
         all_ch |= in->channels;
         for (c = in->channels, cv = channels; c; c >>= 1, cv++)
             if (c & 1)
-                *cv += val;
+                *cv += (unsigned)val;
     }
     val = (int32_t)lcg_next(&ws->dither_state) >> 16;
     for (c = all_ch, cv = channels; c; c >>= 1, cv++)