linux-kernel - [char-misc] mei: prevent unloading mei hw modules while the device is opened.

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Date:	Thu, 18 Jun 2015 11:41:03 +0300
From:	Tomas Winkler <tomas.winkler@...el.com>
To:	gregkh@...uxfoundation.org
Cc:	arnd@...db.de, linux-kernel@...r.kernel.org,
	Tomas Winkler <tomas.winkler@...el.com>,
	<stable@...r.kernel.org>,
	Alexander Usyskin <alexander.usyskin@...el.com>
Subject: [char-misc] mei: prevent unloading mei hw modules while the device is opened.

chrdev_open() increases reference counter on cdev->owner. Instead of
assigning the owner to mei subsystem, the owner has to be set to the
underlaying HW module (mei_me or mei_txe), so once the device is opened
the HW module cannot be unloaded.

Cc: <stable@...r.kernel.org> #3.17+
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
---
 drivers/misc/mei/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 8eb0a9500a90..e9513d651cd3 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -682,7 +682,7 @@ int mei_register(struct mei_device *dev, struct device *parent)
 	/* Fill in the data structures */
 	devno = MKDEV(MAJOR(mei_devt), dev->minor);
 	cdev_init(&dev->cdev, &mei_fops);
-	dev->cdev.owner = mei_fops.owner;
+	dev->cdev.owner = parent->driver->owner;
 
 	/* Add the device */
 	ret = cdev_add(&dev->cdev, devno, 1);
-- 
2.4.3

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