[FFmpeg-cvslog] avcodec/alsdec: No channels cannot be accessed

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Jul  2 14:22:48 2022 +0200| [9fec43a92d7304fc594dcf73c6dd3144b855617d] | committer: Michael Niedermayer

avcodec/alsdec: No channels cannot be accessed

Fixes: out of array access
Fixes: 48145/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALS_fuzzer-5054524173189120

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9fec43a92d7304fc594dcf73c6dd3144b855617d
---

 libavcodec/alsdec.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c
index bf961a03f5..7031fa0acb 100644
--- a/libavcodec/alsdec.c
+++ b/libavcodec/alsdec.c
@@ -361,6 +361,9 @@ static av_cold int read_specific_config(ALSDecContext *ctx)
         return AVERROR_PATCHWELCOME;
     }
 
+    if (avctx->ch_layout.nb_channels == 0)
+        return AVERROR_INVALIDDATA;
+
     ctx->cur_frame_length = sconf->frame_length;
 
     // read channel config