Merge tag 'driver-core-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

torvalds · torvalds · commit 434ac47d0ff3 · 2013-09-29T13:45:23.000-07:00
Pull driver core / sysfs fixes from Greg KH:
 "Here are 2 fixes for 3.12-rc3.  One fixes a sysfs problem with
  mounting caused by 3.12-rc1, and the other is a bug reported by the
  chromeos developers with the driver core.

  Both have been in linux-next for a bit"

* tag 'driver-core-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core : Fix use after free of dev-&gt;parent in device_shutdown
  sysfs: Allow mounting without CONFIG_NET
diff --git a/drivers/base/core.c b/drivers/base/core.c
@@ -2017,7 +2017,7 @@ EXPORT_SYMBOL_GPL(device_move);
  */
 void device_shutdown(void)
 {
-	struct device *dev;
+	struct device *dev, *parent;
 
 	spin_lock(&devices_kset->list_lock);
 	/*
@@ -2034,7 +2034,7 @@ void device_shutdown(void)
 		 * prevent it from being freed because parent's
 		 * lock is to be held
 		 */
-		get_device(dev->parent);
+		parent = get_device(dev->parent);
 		get_device(dev);
 		/*
 		 * Make sure the device is off the kset list, in the
@@ -2044,8 +2044,8 @@ void device_shutdown(void)
 		spin_unlock(&devices_kset->list_lock);
 
 		/* hold lock to avoid race with probe/release */
-		if (dev->parent)
-			device_lock(dev->parent);
+		if (parent)
+			device_lock(parent);
 		device_lock(dev);
 
 		/* Don't allow any more runtime suspends */
@@ -2063,11 +2063,11 @@ void device_shutdown(void)
 		}
 
 		device_unlock(dev);
-		if (dev->parent)
-			device_unlock(dev->parent);
+		if (parent)
+			device_unlock(parent);
 
 		put_device(dev);
-		put_device(dev->parent);
+		put_device(parent);
 
 		spin_lock(&devices_kset->list_lock);
 	}
