USB: spcp8x5: fix port-data memory leak

Fix port-data memory leak by replacing attach and release with
port_probe and port_remove.

Since commit 0998d063 (device-core: Ensure drvdata = NULL when no
driver is bound) the port private data is no longer freed at release as
it is no longer accessible.

Compile-only tested.

Cc: <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/spcp8x5.c

@@ -157,13 +157,10 @@ struct spcp8x5_private {
 	u8 			line_status;
 };
 
-/* desc : when device plug in,this function would be called.
- * thanks to usb_serial subsystem,then do almost every things for us. And what
- * we should do just alloc the buffer */
-static int spcp8x5_startup(struct usb_serial *serial)
+static int spcp8x5_port_probe(struct usb_serial_port *port)
 {
+	struct usb_serial *serial = port->serial;
 	struct spcp8x5_private *priv;
-	int i;
 	enum spcp8x5_type type = SPCP825_007_TYPE;
 	u16 product = le16_to_cpu(serial->dev->descriptor.idProduct);
 
@@ -180,34 +177,27 @@ static int spcp8x5_startup(struct usb_serial *serial)
 		type = SPCP825_PHILIP_TYPE;
 	dev_dbg(&serial->dev->dev, "device type = %d\n", (int)type);
 
-	for (i = 0; i < serial->num_ports; ++i) {
-		priv = kzalloc(sizeof(struct spcp8x5_private), GFP_KERNEL);
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
-			goto cleanup;
+		return -ENOMEM;
 
 	spin_lock_init(&priv->lock);
 	init_waitqueue_head(&priv->delta_msr_wait);
 	priv->type = type;
-		usb_set_serial_port_data(serial->port[i] , priv);
-	}
+
+	usb_set_serial_port_data(port , priv);
 
 	return 0;
-cleanup:
-	for (--i; i >= 0; --i) {
-		priv = usb_get_serial_port_data(serial->port[i]);
-		kfree(priv);
-		usb_set_serial_port_data(serial->port[i] , NULL);
-	}
-	return -ENOMEM;
 }
 
-/* call when the device plug out. free all the memory alloced by probe */
-static void spcp8x5_release(struct usb_serial *serial)
+static int spcp8x5_port_remove(struct usb_serial_port *port)
 {
-	int i;
+	struct spcp8x5_private *priv;
 
-	for (i = 0; i < serial->num_ports; i++)
-		kfree(usb_get_serial_port_data(serial->port[i]));
+	priv = usb_get_serial_port_data(port);
+	kfree(priv);
+
+	return 0;
 }
 
 /* set the modem control line of the device.
@@ -649,8 +639,8 @@ static struct usb_serial_driver spcp8x5_device = {
 	.ioctl 			= spcp8x5_ioctl,
 	.tiocmget 		= spcp8x5_tiocmget,
 	.tiocmset 		= spcp8x5_tiocmset,
-	.attach 		= spcp8x5_startup,
-	.release 		= spcp8x5_release,
+	.port_probe		= spcp8x5_port_probe,
+	.port_remove		= spcp8x5_port_remove,
 	.process_read_urb	= spcp8x5_process_read_urb,
 };