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alistair23-linux
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USB: race fixes for usb-serial, step 2 

- take BKL before looking up a driver to associate with a device to make
  sure the module is not unloaded after looking up but before association
  & bumping module count

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
hifive-unleashed-5.1
Oliver Neukum 2007-01-13 07:31:27 +01:00 committed by Greg Kroah-Hartman
parent 34ef50e5b1
commit 4b10f0f3a0
1 changed files with 12 additions and 2 deletions
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14
drivers/usb/serial/usb-serial.c
View File

@ -685,14 +685,17 @@ int usb_serial_probe(struct usb_interface *interface,
int num_ports = 0;
int max_endpoints;
lock_kernel(); /* guard against unloading a serial driver module */
type = search_serial_device(interface);
if (!type) {
unlock_kernel();
dbg("none matched");
return -ENODEV;
}
serial = create_serial (dev, interface, type);
if (!serial) {
unlock_kernel();
dev_err(&interface->dev, "%s - out of memory\n", __FUNCTION__);
return -ENOMEM;
}
@ -702,6 +705,7 @@ int usb_serial_probe(struct usb_interface *interface,
const struct usb_device_id *id;
if (!try_module_get(type->driver.owner)) {
unlock_kernel();
dev_err(&interface->dev, "module get failed, exiting\n");
kfree (serial);
return -EIO;
@ -712,6 +716,7 @@ int usb_serial_probe(struct usb_interface *interface,
module_put(type->driver.owner);
if (retval) {
unlock_kernel();
dbg ("sub driver rejected device");
kfree (serial);
return retval;
@ -781,6 +786,7 @@ int usb_serial_probe(struct usb_interface *interface,
* properly during a later invocation of usb_serial_probe
*/
if (num_bulk_in == 0 || num_bulk_out == 0) {
unlock_kernel();
dev_info(&interface->dev, "PL-2303 hack: descriptors matched but endpoints did not\n");
kfree (serial);
return -ENODEV;
@ -796,6 +802,7 @@ int usb_serial_probe(struct usb_interface *interface,
if (type == &usb_serial_generic_device) {
num_ports = num_bulk_out;
if (num_ports == 0) {
unlock_kernel();
dev_err(&interface->dev, "Generic device with no bulk out, not allowed.\n");
kfree (serial);
return -EIO;
@ -806,6 +813,7 @@ int usb_serial_probe(struct usb_interface *interface,
/* if this device type has a calc_num_ports function, call it */
if (type->calc_num_ports) {
if (!try_module_get(type->driver.owner)) {
unlock_kernel();
dev_err(&interface->dev, "module get failed, exiting\n");
kfree (serial);
return -EIO;
@ -831,6 +839,8 @@ int usb_serial_probe(struct usb_interface *interface,
max_endpoints = max(max_endpoints, num_interrupt_out);
max_endpoints = max(max_endpoints, (int)serial->num_ports);
serial->num_port_pointers = max_endpoints;
unlock_kernel();
dbg("%s - setting up %d port structures for this device", __FUNCTION__, max_endpoints);
for (i = 0; i < max_endpoints; ++i) {
port = kzalloc(sizeof(struct usb_serial_port), GFP_KERNEL);
@ -1187,7 +1197,7 @@ static void fixup_generic(struct usb_serial_driver *device)
set_to_generic_if_null(device, shutdown);
}
int usb_serial_register(struct usb_serial_driver *driver)
int usb_serial_register(struct usb_serial_driver *driver) /* must be called with BKL held */
{
int retval;
@ -1211,7 +1221,7 @@ int usb_serial_register(struct usb_serial_driver *driver)
}
void usb_serial_deregister(struct usb_serial_driver *device)
void usb_serial_deregister(struct usb_serial_driver *device) /* must be called with BKL held */
{
info("USB Serial deregistering driver %s", device->description);
list_del(&device->driver_list);