[FFmpeg-cvslog] avcodec/ffwavesynth: Check ts_end - ts_start for overflow

[Michael Niedermayer]

ffmpeg | branch: release/4.1 | Michael Niedermayer <michael at niedermayer.cc> | Sun Jun 16 16:12:42 2019 +0200| [c434a043ac081e0f5d8c166f8416346002d462fa] | committer: Michael Niedermayer

avcodec/ffwavesynth: Check ts_end - ts_start for overflow

Fixes: signed integer overflow: 2314885530818453536 - -8926099139098304480 cannot be represented in type 'long'
Fixes: 15259/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFWAVESYNTH_fuzzer-5764366093254656

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 2db7a3bc4acdd293ed10b71e55f16a45ca28b629)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c434a043ac081e0f5d8c166f8416346002d462fa
---

 libavcodec/ffwavesynth.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/ffwavesynth.c b/libavcodec/ffwavesynth.c
index 9d055e4019..a66113972b 100644
--- a/libavcodec/ffwavesynth.c
+++ b/libavcodec/ffwavesynth.c
@@ -267,7 +267,10 @@ static int wavesynth_parse_extradata(AVCodecContext *avc)
         in->type     = AV_RL32(edata + 16);
         in->channels = AV_RL32(edata + 20);
         edata += 24;
-        if (in->ts_start < cur_ts || in->ts_end <= in->ts_start)
+        if (in->ts_start < cur_ts ||
+            in->ts_end <= in->ts_start ||
+            (uint64_t)in->ts_end - in->ts_start > INT64_MAX
+        )
             return AVERROR(EINVAL);
         cur_ts = in->ts_start;
         dt = in->ts_end - in->ts_start;