UIO: fix race in device_create

There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index 55cc7b80422a..0a12e90ad416 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -649,15 +649,14 @@ int __uio_register_device(struct module *owner,
         if (ret)
                 goto err_get_minor;
 
-        idev->dev = device_create(uio_class->class, parent,
-                                  MKDEV(uio_major, idev->minor),
-                                  "uio%d", idev->minor);
+        idev->dev = device_create_drvdata(uio_class->class, parent,
+                                          MKDEV(uio_major, idev->minor), idev,
+                                          "uio%d", idev->minor);
         if (IS_ERR(idev->dev)) {
                 printk(KERN_ERR "UIO: device register failed\n");
                 ret = PTR_ERR(idev->dev);
                 goto err_device_create;
         }
-        dev_set_drvdata(idev->dev, idev);
 
         ret = uio_dev_add_attributes(idev);
         if (ret)