devres: WARN() and return, don't crash on device_del() of uninitialized device
I just debugged an obscure crash caused by a device_del() of a all NULL'd
out struct device (in usb-serial) and found that a patch like this one would
have saved me time (in addition to improved chances of a bug report from
users hitting similar driver bugs).
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index e8beb8e..05dd307 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -428,6 +428,9 @@
{
unsigned long flags;
+ /* Looks like an uninitialized device structure */
+ if (WARN_ON(dev->devres_head.next == NULL))
+ return -ENODEV;
spin_lock_irqsave(&dev->devres_lock, flags);
return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
flags);