[PATCH 07/10] Driver-core: Fix bogus 0 error return in device_add()

[Greg Kroah-Hartman <gregkh@suse.de>]

From: Thomas Gleixner <tglx@linutronix.de>

If device_add() is called with a device which does not have dev->p set
up, then device_private_init() is called. If that succeeds, then the
error variable is set to 0. Now if the dev_name(dev) check further
down fails, then device_add() correctly terminates, but returns 0.
That of course lets the driver progress. If later another driver uses
this half set up device as parent then device_add() of the child
device explodes and renders sysfs completely unusable.

Set the error to -EINVAL if dev_name() check fails.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: "Hans J. Koch" <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/base/core.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 83afc8b..2820257 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -909,8 +909,10 @@ int device_add(struct device *dev)
 		dev->init_name = NULL;
 	}
 
-	if (!dev_name(dev))
+	if (!dev_name(dev)) {
+		error = -EINVAL;
 		goto name_error;
+	}
 
 	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
 
-- 
1.6.5.7