[FFmpeg-cvslog] avcodec/vmdaudio: Check block_align more

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Mon Jan  6 01:38:21 2020 +0100| [92503fd8a940d56b5b327b914a7f418a67254bec] | committer: Michael Niedermayer

avcodec/vmdaudio: Check block_align more

Fixes: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
Fixes: 19788/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VMDAUDIO_fuzzer-5743379690553344

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 06f6857b54a7fbbd087b0803f75bed44abed50d9)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=92503fd8a940d56b5b327b914a7f418a67254bec
---

 libavcodec/vmdaudio.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavcodec/vmdaudio.c b/libavcodec/vmdaudio.c
index c7826fa3ce..dfbd49fd84 100644
--- a/libavcodec/vmdaudio.c
+++ b/libavcodec/vmdaudio.c
@@ -76,7 +76,9 @@ static av_cold int vmdaudio_decode_init(AVCodecContext *avctx)
         av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
         return AVERROR(EINVAL);
     }
-    if (avctx->block_align < 1 || avctx->block_align % avctx->channels) {
+    if (avctx->block_align < 1 || avctx->block_align % avctx->channels ||
+        avctx->block_align > INT_MAX - avctx->channels
+    ) {
         av_log(avctx, AV_LOG_ERROR, "invalid block align\n");
         return AVERROR(EINVAL);
     }