Bluetooth: Fix redundant encryption request for reauthentication

commit 09da1f34 upstream.

When we're performing reauthentication (in order to elevate the
security level from an unauthenticated key to an authenticated one) we
do not need to issue any encryption command once authentication
completes. Since the trigger for the encryption HCI command is the
ENCRYPT_PEND flag this flag should not be set in this scenario.
Instead, the REAUTH_PEND flag takes care of all necessary steps for
reauthentication.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
[bwh: Backported to 3.2:
 - Adjust context
 - s/conn->flags/conn->pend/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

net/bluetooth/hci_conn.c

@@ -610,14 +610,17 @@ static int hci_conn_auth(struct hci_conn *conn, __u8 sec_level, __u8 auth_type)
 	if (!test_and_set_bit(HCI_CONN_AUTH_PEND, &conn->pend)) {
 		struct hci_cp_auth_requested cp;
 
-		/* encrypt must be pending if auth is also pending */
-		set_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend);
-
 		cp.handle = cpu_to_le16(conn->handle);
 		hci_send_cmd(conn->hdev, HCI_OP_AUTH_REQUESTED,
 							sizeof(cp), &cp);
+
+		/* If we're already encrypted set the REAUTH_PEND flag,
+		 * otherwise set the ENCRYPT_PEND.
+		 */
 		if (conn->key_type != 0xff)
 			set_bit(HCI_CONN_REAUTH_PEND, &conn->pend);
+		else
+			set_bit(HCI_CONN_ENCRYPT_PEND, &conn->pend);
 	}
 
 	return 0;