xen/xenbus: Check before dereferencing it.

.. we do the check whether 'xdev' is NULL - but after we have
dereferenced it.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c
index 60adf919d78ddd46a4e6e2cadad27bd053bfa392..331589afcfb4605a995c98137c5602c07d50d6b7 100644 (file)
--- a/drivers/xen/xenbus/xenbus_probe_backend.c
+++ b/drivers/xen/xenbus/xenbus_probe_backend.c
@@ -103,10 +103,11 @@ static int xenbus_uevent_backend(struct device *dev,
                return -ENODEV;
 
        xdev = to_xenbus_device(dev);
-       bus = container_of(xdev->dev.bus, struct xen_bus_type, bus);
        if (xdev == NULL)
                return -ENODEV;
 
+       bus = container_of(xdev->dev.bus, struct xen_bus_type, bus);
+
        if (add_uevent_var(env, "MODALIAS=xen-backend:%s", xdev->devicetype))
                return -ENOMEM;