Bluetooth: Fix properly ignoring LTKs of unknown types

In case there are new LTK types in the future we shouldn't just blindly
assume that != MGMT_LTK_UNAUTHENTICATED means that the key is
authenticated. This patch adds explicit checks for each allowed key type
in the form of a switch statement and skips any key which has an unknown
value.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

net/bluetooth/mgmt.c

@@ -4546,10 +4546,16 @@ static int load_long_term_keys(struct sock *sk, struct hci_dev *hdev,
 		else
 			type = HCI_SMP_LTK_SLAVE;
 
-		if (key->type == MGMT_LTK_UNAUTHENTICATED)
+		switch (key->type) {
+		case MGMT_LTK_UNAUTHENTICATED:
 			authenticated = 0x00;
-		else
+			break;
+		case MGMT_LTK_AUTHENTICATED:
 			authenticated = 0x01;
+			break;
+		default:
+			continue;
+		}
 
 		hci_add_ltk(hdev, &key->addr.bdaddr, addr_type, type,
 			    authenticated, key->val, key->enc_size, key->ediv,