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| author | Takashi Iwai <tiwai@suse.de> | 2019-04-12 11:37:19 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-15 11:54:11 +0200 |
| commit | b323914cd033f975b5d544b188a3ed1948f02936 (patch) | |
| tree | 47bb2b7152a4893fcb7c57e6dd5278bdf8732869 /sound | |
| parent | 3af96f3497b7ee087ce2bc5feae1390f57b87dc7 (diff) | |
| download | linux-stable-b323914cd033f975b5d544b188a3ed1948f02936.tar.gz linux-stable-b323914cd033f975b5d544b188a3ed1948f02936.tar.bz2 linux-stable-b323914cd033f975b5d544b188a3ed1948f02936.zip | |
ALSA: seq: Cover unsubscribe_port() in list_mutex
commit 7c32ae35fbf9cffb7aa3736f44dec10c944ca18e upstream.
The call of unsubscribe_port() which manages the group count and
module refcount from delete_and_unsubscribe_port() looks racy; it's
not covered by the group list lock, and it's likely a cause of the
reported unbalance at port deletion. Let's move the call inside the
group list_mutex to plug the hole.
Reported-by: syzbot+e4c8abb920efa77bace9@syzkaller.appspotmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/core/seq/seq_ports.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/core/seq/seq_ports.c b/sound/core/seq/seq_ports.c index 24d90abfc64d..da31aa8e216e 100644 --- a/sound/core/seq/seq_ports.c +++ b/sound/core/seq/seq_ports.c @@ -550,10 +550,10 @@ static void delete_and_unsubscribe_port(struct snd_seq_client *client, list_del_init(list); grp->exclusive = 0; write_unlock_irq(&grp->list_lock); - up_write(&grp->list_mutex); if (!empty) unsubscribe_port(client, port, grp, &subs->info, ack); + up_write(&grp->list_mutex); } /* connect two ports */ |