[FFmpeg-cvslog] avformat/wavdec: Use 64bit in new_pos computation

[Michael Niedermayer]

ffmpeg | branch: release/4.4 | Michael Niedermayer <michael at niedermayer.cc> | Tue Apr 27 20:57:02 2021 +0200| [8a3eb4498b10d16fb973443826bffd117ad9e7c6] | committer: Michael Niedermayer

avformat/wavdec: Use 64bit in new_pos computation

Fixes: signed integer overflow: 129 * 16711680 cannot be represented in type 'int'
Fixes: 29102/clusterfuzz-testcase-minimized-ffmpeg_dem_WAV_fuzzer-6742285317439488

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 9b57d2f0a967195dc1c72fda8f3a983a0132a243)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8a3eb4498b10d16fb973443826bffd117ad9e7c6
---

 libavformat/wavdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/wavdec.c b/libavformat/wavdec.c
index 8214ab8498..212d198e99 100644
--- a/libavformat/wavdec.c
+++ b/libavformat/wavdec.c
@@ -718,7 +718,7 @@ smv_retry:
         if (wav->smv_last_stream) {
             uint64_t old_pos = avio_tell(s->pb);
             uint64_t new_pos = wav->smv_data_ofs +
-                wav->smv_block * wav->smv_block_size;
+                wav->smv_block * (int64_t)wav->smv_block_size;
             if (avio_seek(s->pb, new_pos, SEEK_SET) < 0) {
                 ret = AVERROR_EOF;
                 goto smv_out;