From 4b10f0f3a0d4caa8b615cd1f770a70912967a3cd Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Sat, 13 Jan 2007 07:31:27 +0100 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/usb-serial.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 3780362eb9f0..685fb69bcc32 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -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); -- 2.20.1