[FFmpeg-cvslog] avformat/alp: Check num_channels

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Mar 19 23:28:53 2022 +0100| [2e069f6b69475683207ea05deb269f9c532633bb] | committer: Michael Niedermayer

avformat/alp: Check num_channels

Fixes: division by 0
Fixes: 45615/clusterfuzz-testcase-minimized-ffmpeg_dem_ALP_fuzzer-582660348405350
Fixes: 45625/clusterfuzz-testcase-minimized-ffmpeg_dem_ALP_fuzzer-4821437943250944
Fixes: 45839/clusterfuzz-testcase-minimized-ffmpeg_IO_DEMUXER_fuzzer-5857286998851584.fuzz
Fixes: 45844/clusterfuzz-testcase-minimized-ffmpeg_IO_DEMUXER_fuzzer-6552705772945408

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2e069f6b69475683207ea05deb269f9c532633bb
---

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

diff --git a/libavformat/alp.c b/libavformat/alp.c
index f2428a9e3b..40e4890a38 100644
--- a/libavformat/alp.c
+++ b/libavformat/alp.c
@@ -122,7 +122,7 @@ static int alp_read_header(AVFormatContext *s)
     par->format                 = AV_SAMPLE_FMT_S16;
     par->sample_rate            = hdr->sample_rate;
 
-    if (hdr->num_channels > 2)
+    if (hdr->num_channels > 2 || hdr->num_channels == 0)
         return AVERROR_INVALIDDATA;
 
     av_channel_layout_default(&par->ch_layout, hdr->num_channels);