From: Johannes Thumshirn <jthumshirn@suse.de>
Date: Tue, 10 May 2016 10:39:44 +0000 (+0200)
Subject: mcb: Acquire reference to device in probe
X-Git-Tag: v4.7-rc4~8^2~6
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=7bc364097a89;p=linux-block.git

mcb: Acquire reference to device in probe

mcb_probe() does not aqcuire a reference to the probed device but drops one
when removing the device. As it is actually using the device, it should grab
a reference via get_device().

This could lead to a panic found with a rmmod/modprobe stress test

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reported-by: Andreas Werner <andreas.werner@men.de>
Tested-by: Andreas Werner <andreas.werner@men.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
index b73c6e7d28e4..f5923c253f7e 100644
--- a/drivers/mcb/mcb-core.c
+++ b/drivers/mcb/mcb-core.c
@@ -66,6 +66,7 @@ static int mcb_probe(struct device *dev)
 	if (!found_id)
 		return -ENODEV;
 
+	get_device(dev);
 	return mdrv->probe(mdev, found_id);
 }