[FFmpeg-cvslog] avcodec/wavpack: Fix runtime error: signed integer overflow: 2013265955 - -134217694 cannot be represented in type 'int'

[Michael Niedermayer]

ffmpeg | branch: release/3.1 | Michael Niedermayer <michael at niedermayer.cc> | Wed May 31 22:53:02 2017 +0200| [4007ba9833cb0725124f22147ca0523857ff5982] | committer: Michael Niedermayer

avcodec/wavpack: Fix runtime error: signed integer overflow: 2013265955 - -134217694 cannot be represented in type 'int'

Fixes: 1922/clusterfuzz-testcase-minimized-5561194112876544

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 a47273c803edfbc43793349b74429ae29b05c003)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4007ba9833cb0725124f22147ca0523857ff5982
---

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

diff --git a/libavcodec/wavpack.c b/libavcodec/wavpack.c
index 3bc345e797..9ce074d975 100644
--- a/libavcodec/wavpack.c
+++ b/libavcodec/wavpack.c
@@ -239,7 +239,7 @@ static int wv_get_value(WavpackFrameContext *ctx, GetBitContext *gb,
             if (get_bits_left(gb) <= 0)
                 goto error;
             if (get_bits1(gb)) {
-                add -= (mid - base);
+                add -= (mid - (unsigned)base);
                 base = mid;
             } else
                 add = mid - base - 1;