Bluetooth: 6lowpan: add missing l2cap_chan_lock()

l2cap_chan_close() needs to be called in l2cap_chan_lock(), otherwise
l2cap_le_sig_cmd() etc. may run concurrently.

Add missing locks around l2cap_chan_close().

Fixes: 6b8d4a6a0314 ("Bluetooth: 6LoWPAN: Use connected oriented channel instead of fixed one")
Signed-off-by: Pauli Virtanen <[e-mail]>
Signed-off-by: Luiz Augusto von Dentz <[e-mail]>

net/bluetooth/6lowpan.c

···
 
 	BT_DBG("peer %p chan %p", peer, peer->chan);
 
+	l2cap_chan_lock(peer->chan);
 	l2cap_chan_close(peer->chan, ENOENT);
+	l2cap_chan_unlock(peer->chan);
 
 	return 0;
 }
···
 
 	mutex_lock(&set_lock);
 	if (listen_chan) {
+		l2cap_chan_lock(listen_chan);
 		l2cap_chan_close(listen_chan, 0);
+		l2cap_chan_unlock(listen_chan);
 		l2cap_chan_put(listen_chan);
 	}
 
···
 
 		mutex_lock(&set_lock);
 		if (listen_chan) {
+			l2cap_chan_lock(listen_chan);
 			l2cap_chan_close(listen_chan, 0);
+			l2cap_chan_unlock(listen_chan);
 			l2cap_chan_put(listen_chan);
 			listen_chan = NULL;
 		}
···
 	debugfs_remove(lowpan_control_debugfs);
 
 	if (listen_chan) {
+		l2cap_chan_lock(listen_chan);
 		l2cap_chan_close(listen_chan, 0);
+		l2cap_chan_unlock(listen_chan);
 		l2cap_chan_put(listen_chan);
 	}