USB: quatech2: fix port-data memory leaks

Fix port-data memory leak by moving port data allocation and
deallocation to port_probe and port_remove.

Since commit 0998d0631001288 (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.

Note that this also fixes memory leaks in the error path of attach where
the write urbs were not freed on errors.

Make sure all interface-data deallocation is done in release by moving
the read urb deallocation from disconnect.

Note that the write urb is killed during close so that the call in
disconnect was superfluous.

Compile-only tested.

Cc: Bill Pemberton <wfp5p@virginia.edu>
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/quatech2.c

@@ -143,12 +143,12 @@ static void qt2_read_bulk_callback(struct urb *urb);
 
 static void qt2_release(struct usb_serial *serial)
 {
-	int i;
+	struct qt2_serial_private *serial_priv;
 
-	kfree(usb_get_serial_data(serial));
+	serial_priv = usb_get_serial_data(serial);
 
-	for (i = 0; i < serial->num_ports; i++)
-		kfree(usb_get_serial_port_data(serial->port[i]));
+	usb_free_urb(serial_priv->read_urb);
+	kfree(serial_priv);
 }
 
 static inline int calc_baud_divisor(int baudrate)
@@ -464,21 +464,9 @@ static void qt2_close(struct usb_serial_port *port)
 static void qt2_disconnect(struct usb_serial *serial)
 {
 	struct qt2_serial_private *serial_priv = usb_get_serial_data(serial);
-	struct qt2_port_private *port_priv;
-	int i;
 
 	if (serial_priv->read_urb->status == -EINPROGRESS)
 		usb_kill_urb(serial_priv->read_urb);
-
-	usb_free_urb(serial_priv->read_urb);
-
-	for (i = 0; i < serial->num_ports; i++) {
-		port_priv = usb_get_serial_port_data(serial->port[i]);
-
-		if (port_priv->write_urb->status == -EINPROGRESS)
-			usb_kill_urb(port_priv->write_urb);
-		usb_free_urb(port_priv->write_urb);
-	}
 }
 
 static int get_serial_info(struct usb_serial_port *port,
@@ -773,11 +761,9 @@ static void qt2_read_bulk_callback(struct urb *urb)
 
 static int qt2_setup_urbs(struct usb_serial *serial)
 {
-	struct usb_serial_port *port;
 	struct usb_serial_port *port0;
 	struct qt2_serial_private *serial_priv;
-	struct qt2_port_private *port_priv;
-	int pcount, status;
+	int status;
 
 	port0 = serial->port[0];
 
@@ -795,30 +781,6 @@ static int qt2_setup_urbs(struct usb_serial *serial)
 			  sizeof(serial_priv->read_buffer),
 			  qt2_read_bulk_callback, serial);
 
-	/* setup write_urb for each port */
-	for (pcount = 0; pcount < serial->num_ports; pcount++) {
-
-		port = serial->port[pcount];
-		port_priv = usb_get_serial_port_data(port);
-
-		port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
-		if (!port_priv->write_urb) {
-			dev_err(&serial->dev->dev,
-				"failed to alloc write_urb for port %i\n",
-				pcount);
-			return -ENOMEM;
-		}
-
-		usb_fill_bulk_urb(port_priv->write_urb,
-				  serial->dev,
-				  usb_sndbulkpipe(serial->dev,
-						  port0->
-						  bulk_out_endpointAddress),
-				  port_priv->write_buffer,
-				  sizeof(port_priv->write_buffer),
-				  qt2_write_bulk_callback, port);
-	}
-
 	status = usb_submit_urb(serial_priv->read_urb, GFP_KERNEL);
 	if (status != 0) {
 		dev_err(&serial->dev->dev,
@@ -828,14 +790,12 @@ static int qt2_setup_urbs(struct usb_serial *serial)
 	}
 
 	return 0;
-
 }
 
 static int qt2_attach(struct usb_serial *serial)
 {
 	struct qt2_serial_private *serial_priv;
-	struct qt2_port_private *port_priv;
-	int status, pcount;
+	int status;
 
 	/* power on unit */
 	status = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
@@ -855,26 +815,6 @@ static int qt2_attach(struct usb_serial *serial)
 
 	usb_set_serial_data(serial, serial_priv);
 
-	for (pcount = 0; pcount < serial->num_ports; pcount++) {
-		port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
-		if (!port_priv) {
-			dev_err(&serial->dev->dev,
-				"%s- kmalloc(%Zd) failed.\n", __func__,
-				sizeof(*port_priv));
-			pcount--;
-			status = -ENOMEM;
-			goto attach_failed;
-		}
-
-		spin_lock_init(&port_priv->lock);
-		spin_lock_init(&port_priv->urb_lock);
-		init_waitqueue_head(&port_priv->delta_msr_wait);
-
-		port_priv->port = serial->port[pcount];
-
-		usb_set_serial_port_data(serial->port[pcount], port_priv);
-	}
-
 	status = qt2_setup_urbs(serial);
 	if (status != 0)
 		goto attach_failed;
@@ -882,14 +822,53 @@ static int qt2_attach(struct usb_serial *serial)
 	return 0;
 
 attach_failed:
-	for (/* empty */; pcount >= 0; pcount--) {
-		port_priv = usb_get_serial_port_data(serial->port[pcount]);
-		kfree(port_priv);
-	}
 	kfree(serial_priv);
 	return status;
 }
 
+static int qt2_port_probe(struct usb_serial_port *port)
+{
+	struct usb_serial *serial = port->serial;
+	struct qt2_port_private *port_priv;
+	u8 bEndpointAddress;
+
+	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
+	if (!port_priv)
+		return -ENOMEM;
+
+	spin_lock_init(&port_priv->lock);
+	spin_lock_init(&port_priv->urb_lock);
+	init_waitqueue_head(&port_priv->delta_msr_wait);
+	port_priv->port = port;
+
+	port_priv->write_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!port_priv->write_urb) {
+		kfree(port_priv);
+		return -ENOMEM;
+	}
+	bEndpointAddress = serial->port[0]->bulk_out_endpointAddress;
+	usb_fill_bulk_urb(port_priv->write_urb, serial->dev,
+				usb_sndbulkpipe(serial->dev, bEndpointAddress),
+				port_priv->write_buffer,
+				sizeof(port_priv->write_buffer),
+				qt2_write_bulk_callback, port);
+
+	usb_set_serial_port_data(port, port_priv);
+
+	return 0;
+}
+
+static int qt2_port_remove(struct usb_serial_port *port)
+{
+	struct qt2_port_private *port_priv;
+
+	port_priv = usb_get_serial_port_data(port);
+	usb_free_urb(port_priv->write_urb);
+	kfree(port_priv);
+
+	return 0;
+}
+
 static int qt2_tiocmget(struct tty_struct *tty)
 {
 	struct usb_serial_port *port = tty->driver_data;
@@ -1128,6 +1107,8 @@ static struct usb_serial_driver qt2_device = {
 	.attach              = qt2_attach,
 	.release             = qt2_release,
 	.disconnect          = qt2_disconnect,
+	.port_probe          = qt2_port_probe,
+	.port_remove         = qt2_port_remove,
 	.dtr_rts             = qt2_dtr_rts,
 	.break_ctl           = qt2_break_ctl,
 	.tiocmget            = qt2_tiocmget,