USB: mos7720: fix port-data memory leak

commit 4230af572f95b3115bba1ee6fb95681f3851ab26 upstream.

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 patch also fixes a second port-data memory leak in the
error path of attach, should parallel-port initialisation fail.

Compile-only tested.

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

diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index a07dd3c8cfef3e408fbaa4bba593267621ccec71..eb847676a35372237655e1fbd0ce8d34b9adb549 100644 (file)
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -2023,9 +2023,7 @@ static int mos7720_ioctl(struct tty_struct *tty,
 
 static int mos7720_startup(struct usb_serial *serial)
 {
-       struct moschip_port *mos7720_port;
        struct usb_device *dev;
-       int i;
        char data;
        u16 product;
        int ret_val;
@@ -2063,29 +2061,6 @@ static int mos7720_startup(struct usb_serial *serial)
                serial->port[1]->interrupt_in_buffer = NULL;
        }
 
-
-       /* set up serial port private structures */
-       for (i = 0; i < serial->num_ports; ++i) {
-               mos7720_port = kzalloc(sizeof(struct moschip_port), GFP_KERNEL);
-               if (mos7720_port == NULL) {
-                       dev_err(&dev->dev, "%s - Out of memory\n", __func__);
-                       return -ENOMEM;
-               }
-
-               /* Initialize all port interrupt end point to port 0 int
-                * endpoint.  Our device has only one interrupt endpoint
-                * common to all ports */
-               serial->port[i]->interrupt_in_endpointAddress =
-                               serial->port[0]->interrupt_in_endpointAddress;
-
-               mos7720_port->port = serial->port[i];
-               usb_set_serial_port_data(serial->port[i], mos7720_port);
-
-               dbg("port number is %d", serial->port[i]->number);
-               dbg("serial number is %d", serial->minor);
-       }
-
-
        /* setting configuration feature to one */
        usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
                        (__u8)0x03, 0x00, 0x01, 0x00, NULL, 0x00, 5*HZ);
@@ -2113,8 +2088,6 @@ static int mos7720_startup(struct usb_serial *serial)
 
 static void mos7720_release(struct usb_serial *serial)
 {
-       int i;
-
 #ifdef CONFIG_USB_SERIAL_MOS7715_PARPORT
        /* close the parallel port */
 
@@ -2153,9 +2126,36 @@ static void mos7720_release(struct usb_serial *serial)
                kref_put(&mos_parport->ref_count, destroy_mos_parport);
        }
 #endif
-       /* free private structure allocated for serial port */
-       for (i = 0; i < serial->num_ports; ++i)
-               kfree(usb_get_serial_port_data(serial->port[i]));
+}
+
+static int mos7720_port_probe(struct usb_serial_port *port)
+{
+       struct moschip_port *mos7720_port;
+
+       mos7720_port = kzalloc(sizeof(*mos7720_port), GFP_KERNEL);
+       if (!mos7720_port)
+               return -ENOMEM;
+
+       /* Initialize all port interrupt end point to port 0 int endpoint.
+        * Our device has only one interrupt endpoint common to all ports.
+        */
+       port->interrupt_in_endpointAddress =
+               port->serial->port[0]->interrupt_in_endpointAddress;
+       mos7720_port->port = port;
+
+       usb_set_serial_port_data(port, mos7720_port);
+
+       return 0;
+}
+
+static int mos7720_port_remove(struct usb_serial_port *port)
+{
+       struct moschip_port *mos7720_port;
+
+       mos7720_port = usb_get_serial_port_data(port);
+       kfree(mos7720_port);
+
+       return 0;
 }
 
 static struct usb_serial_driver moschip7720_2port_driver = {
@@ -2173,6 +2173,8 @@ static struct usb_serial_driver moschip7720_2port_driver = {
        .probe                  = mos77xx_probe,
        .attach                 = mos7720_startup,
        .release                = mos7720_release,
+       .port_probe             = mos7720_port_probe,
+       .port_remove            = mos7720_port_remove,
        .ioctl                  = mos7720_ioctl,
        .tiocmget               = mos7720_tiocmget,
        .tiocmset               = mos7720_tiocmset,