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 cf241c371a71ffba80b55ef213d9d1f3019aa608..ecf5f3cfa61bcfd560a954992b934ca668ccea02 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);