Bluetooth: Always request for user confirmation for Just Works

To improve security, always give the user-space daemon a chance to
accept or reject a Just Works pairing (LE). The daemon may decide to
auto-accept based on the user's intent.
Signed-off-by: Sonny Sasaka <sonnysasaka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/smp.c

@@ -855,6 +855,7 @@ static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
 	struct smp_chan *smp = chan->data;
 	u32 passkey = 0;
 	int ret = 0;
+	int err;
 
 	/* Initialize key for JUST WORKS */
 	memset(smp->tk, 0, sizeof(smp->tk));
@@ -883,9 +884,16 @@ static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth,
 	    hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
 		smp->method = JUST_WORKS;
 
-	/* If Just Works, Continue with Zero TK */
+	/* If Just Works, Continue with Zero TK and ask user-space for
+	 * confirmation */
 	if (smp->method == JUST_WORKS) {
-		set_bit(SMP_FLAG_TK_VALID, &smp->flags);
+		err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
+						hcon->type,
+						hcon->dst_type,
+						passkey, 1);
+		if (err)
+			return SMP_UNSPECIFIED;
+		set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
 		return 0;
 	}