USB: serial: sierra driver sierra_calc_num_ports() fix
- Removed potential kernel oops from sierra_calc_num_ports() function.
Calling this function twice would likely have caused an oops because
the function releases allocated memory after the first call.
- Modified sierra_probe() function to reflect the changes in
sierra_calc_num_ports().
Signed-off-by: Elina Pasheva <epasheva@sierrawireless.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index bcfe0ac..f047ab5 100644
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -83,18 +83,22 @@
static int sierra_calc_num_ports(struct usb_serial *serial)
{
- int result;
- int *num_ports = usb_get_serial_data(serial);
+ int num_ports = 0;
+ u8 ifnum, numendpoints;
+
dev_dbg(&serial->dev->dev, "%s\n", __func__);
- result = *num_ports;
+ ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
+ numendpoints = serial->interface->cur_altsetting->desc.bNumEndpoints;
- if (result) {
- kfree(num_ports);
- usb_set_serial_data(serial, NULL);
- }
-
- return result;
+ /* Dummy interface present on some SKUs should be ignored */
+ if (ifnum == 0x99)
+ num_ports = 0;
+ else if (numendpoints <= 3)
+ num_ports = 1;
+ else
+ num_ports = (numendpoints-1)/2;
+ return num_ports;
}
static int is_blacklisted(const u8 ifnum,
@@ -140,23 +144,12 @@
{
int result = 0;
struct usb_device *udev;
- int *num_ports;
u8 ifnum;
- u8 numendpoints;
- dev_dbg(&serial->dev->dev, "%s\n", __func__);
-
- num_ports = kmalloc(sizeof(*num_ports), GFP_KERNEL);
- if (!num_ports)
- return -ENOMEM;
-
- ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
- numendpoints = serial->interface->cur_altsetting->desc.bNumEndpoints;
udev = serial->dev;
+ dev_dbg(&udev->dev, "%s\n", __func__);
- /* Figure out the interface number from the serial structure */
ifnum = sierra_calc_interface(serial);
-
/*
* If this interface supports more than 1 alternate
* select the 2nd one
@@ -168,20 +161,6 @@
usb_set_interface(udev, ifnum, 1);
}
- /* Dummy interface present on some SKUs should be ignored */
- if (ifnum == 0x99)
- *num_ports = 0;
- else if (numendpoints <= 3)
- *num_ports = 1;
- else
- *num_ports = (numendpoints-1)/2;
-
- /*
- * save off our num_ports info so that we can use it in the
- * calc_num_ports callback
- */
- usb_set_serial_data(serial, (void *)num_ports);
-
/* ifnum could have changed - by calling usb_set_interface */
ifnum = sierra_calc_interface(serial);