[FFmpeg-cvslog] avformat/cafdec: Check channels

[Michael Niedermayer]

ffmpeg | branch: release/4.4 | Michael Niedermayer <michael at niedermayer.cc> | Fri Apr  9 22:46:13 2021 +0200| [3d2af8afefad5c84d53117a99af6964e7d8f4db8] | committer: Michael Niedermayer

avformat/cafdec: Check channels

Fixes: signed integer overflow: -1184429040541376544 * 32 cannot be represented in type 'long'
Fixes: 31788/clusterfuzz-testcase-minimized-ffmpeg_dem_CAF_fuzzer-6236746338664448

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 641c1db22bb27752b925293ad93f68843baa43bf)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3d2af8afefad5c84d53117a99af6964e7d8f4db8
---

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

diff --git a/libavformat/cafdec.c b/libavformat/cafdec.c
index 76bc4a4655..7f09a27977 100644
--- a/libavformat/cafdec.c
+++ b/libavformat/cafdec.c
@@ -79,7 +79,7 @@ static int read_desc_chunk(AVFormatContext *s)
     st->codecpar->channels    = avio_rb32(pb);
     st->codecpar->bits_per_coded_sample = avio_rb32(pb);
 
-    if (caf->bytes_per_packet < 0 || caf->frames_per_packet < 0)
+    if (caf->bytes_per_packet < 0 || caf->frames_per_packet < 0 || st->codecpar->channels < 0)
         return AVERROR_INVALIDDATA;
 
     /* calculate bit rate for constant size packets */