[Bluetooth]: Don't update disconnect timer for incoming connections

In the case of device pairing the only safe method is to establish
a low-level ACL link. In this case, the remote side should not use
the disconnect timer to give the other side the chance to enter the
PIN code. If the disconnect timer is used, the connection will be
dropped to soon, because it is impossible to identify an actual user
of this link.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bluetooth/hci_event.c

@@ -750,8 +750,6 @@ static inline void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *s
 		if (test_bit(HCI_ENCRYPT, &hdev->flags))
 			conn->link_mode |= HCI_LM_ENCRYPT;
 
-		hci_conn_hold(conn);
-
 		/* Get remote features */
 		if (conn->type == ACL_LINK) {
 			struct hci_cp_read_remote_features cp;
@@ -779,9 +777,11 @@ static inline void hci_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *s
 
 			hci_send_cmd(hdev, OGF_LINK_CTL,
 				OCF_CHANGE_CONN_PTYPE, sizeof(cp), &cp);
+		} else {
+			/* Update disconnect timer */
+			hci_conn_hold(conn);
+			hci_conn_put(conn);
 		}
-
-		hci_conn_put(conn);
 	} else
 		conn->state = BT_CLOSED;