Bluetooth: Temporary keys should be retained during connection

If a key is non persistent then it should not be used in future
connections but it should be kept for current connection. And it
should be removed when connecion is removed.
Signed-off-by: Vishal Agarwal <vishal.agarwal@stericsson.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

include/net/bluetooth/hci_core.h

@@ -314,6 +314,7 @@ struct hci_conn {
 
 	__u8		remote_cap;
 	__u8		remote_auth;
+	bool		flush_key;
 
 	unsigned int	sent;
 

net/bluetooth/hci_core.c

@@ -1330,10 +1330,8 @@ int hci_add_link_key(struct hci_dev *hdev, struct hci_conn *conn, int new_key,
 
 	mgmt_new_link_key(hdev, key, persistent);
 
-	if (!persistent) {
-		list_del(&key->list);
-		kfree(key);
-	}
+	if (conn)
+		conn->flush_key = !persistent;
 
 	return 0;
 }

net/bluetooth/hci_event.c

@@ -1902,6 +1902,8 @@ static inline void hci_disconn_complete_evt(struct hci_dev *hdev, struct sk_buff
 	}
 
 	if (ev->status == 0) {
+		if (conn->type == ACL_LINK && conn->flush_key)
+			hci_remove_link_key(hdev, &conn->dst);
 		hci_proto_disconn_cfm(conn, ev->reason);
 		hci_conn_del(conn);
 	}