[FFmpeg-cvslog] avcodec/ffwavesynth: use uint32_t to compute difference, it is enough

[Michael Niedermayer]

ffmpeg | branch: release/4.1 | Michael Niedermayer <michael at niedermayer.cc> | Fri Jun 21 22:43:23 2019 +0200| [074f40608e19ce7ce44c320dda87836806991d59] | committer: Michael Niedermayer

avcodec/ffwavesynth: use uint32_t to compute difference, it is enough

Fixes: signed integer overflow: 6494225984479297536 - -6043795377581187040 cannot be represented in type 'long'
Fixes: 15285/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFWAVESYNTH_fuzzer-5632780307791872

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 e9dd3c7126097d7c8d4f137db9957b81a219aa2c)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=074f40608e19ce7ce44c320dda87836806991d59
---

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

diff --git a/libavcodec/ffwavesynth.c b/libavcodec/ffwavesynth.c
index b2cc7c8fc1..793eada7a5 100644
--- a/libavcodec/ffwavesynth.c
+++ b/libavcodec/ffwavesynth.c
@@ -215,7 +215,7 @@ static void wavesynth_seek(struct wavesynth_context *ws, int64_t ts)
     ws->next_inter = i;
     ws->next_ts = i < ws->nb_inter ? ws->inter[i].ts_start : INF_TS;
     *last = -1;
-    lcg_seek(&ws->dither_state, ts - ws->cur_ts);
+    lcg_seek(&ws->dither_state, (uint32_t)ts - ws->cur_ts);
     if (ws->pink_need) {
         int64_t pink_ts_cur  = (ws->cur_ts + PINK_UNIT - 1) & ~(PINK_UNIT - 1);
         int64_t pink_ts_next = ts & ~(PINK_UNIT - 1);