USB: Phidget: 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().  It fixes all 3 phidget drivers, which all have
the same problem.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Sean Young <sean@mess.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/usb/misc/phidgetmotorcontrol.c b/drivers/usb/misc/phidgetmotorcontrol.c
index f0113c17cc5a..9b4696f21b22 100644
--- a/drivers/usb/misc/phidgetmotorcontrol.c
+++ b/drivers/usb/misc/phidgetmotorcontrol.c
@@ -365,16 +365,15 @@ static int motorcontrol_probe(struct usb_interface *intf, const struct usb_devic
         } while(value);
         mc->dev_no = bit;
 
-        mc->dev = device_create(phidget_class, &mc->udev->dev, 0,
-                                "motorcontrol%d", mc->dev_no);
+        mc->dev = device_create_drvdata(phidget_class, &mc->udev->dev,
+                                        MKDEV(0, 0), mc,
+                                        "motorcontrol%d", mc->dev_no);
         if (IS_ERR(mc->dev)) {
                 rc = PTR_ERR(mc->dev);
                 mc->dev = NULL;
                 goto out;
         }
 
-        dev_set_drvdata(mc->dev, mc);
-
         if (usb_submit_urb(mc->irq, GFP_KERNEL)) {
                 rc = -EIO;
                 goto out;