USB: g_printer: fix bug in unregistration

commit d5aa475180d03d45c5dc6134aa833f1b3e89c45e upstream.

This patch (as1441) fixes a bug in g_printer.  The gadget driver, char
device number, and class device should be unregistered in reverse
order of registration.  As it is now, when the module is unloaded the
class device gets unregistered first, causing a crash when the unbind
method tries to access it.

This fixes Bugzilla #25882.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Roland Kletzing <devzero@web.de>
CC: Craig W. Nadler <craig@nadler.us>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c
index 2fc8636316c550eb8019799e99299e5551f2aac0..dacc67724fe1bdbc273f3a25a5e2a165ead8d870 100644 (file)
--- a/drivers/usb/gadget/printer.c
+++ b/drivers/usb/gadget/printer.c
@@ -1596,13 +1596,12 @@ cleanup(void)
        int status;
 
        mutex_lock(&usb_printer_gadget.lock_printer_io);
-       class_destroy(usb_gadget_class);
-       unregister_chrdev_region(g_printer_devno, 2);
-
        status = usb_gadget_unregister_driver(&printer_driver);
        if (status)
                ERROR(dev, "usb_gadget_unregister_driver %x\n", status);
 
+       unregister_chrdev_region(g_printer_devno, 2);
+       class_destroy(usb_gadget_class);
        mutex_unlock(&usb_printer_gadget.lock_printer_io);
 }
 module_exit(cleanup);