patch "driver core: bus: Fix a potential double free" added to driver-core-testing

patch "driver core: bus: Fix a potential double free" added to driver-core-testing

[gregkh]

This is a note to let you know that I've just added the patch titled

    driver core: bus: Fix a potential double free

to my driver-core git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
in the driver-core-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the driver-core-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


>From 0f9b011d3321ca1079c7a46c18cb1956fbdb7bcb Mon Sep 17 00:00:00 2001
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Tue, 29 Aug 2017 21:23:49 +0200
Subject: driver core: bus: Fix a potential double free

The .release function of driver_ktype is 'driver_release()'.
This function frees the container_of this kobject.

So, this memory must not be freed explicitly in the error handling path of
'bus_add_driver()'. Otherwise a double free will occur.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/base/bus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index e162c9a789ba..22a64fd3309b 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -698,7 +698,7 @@ int bus_add_driver(struct device_driver *drv)
 
 out_unregister:
 	kobject_put(&priv->kobj);
-	kfree(drv->p);
+	/* drv->p is freed in driver_release()  */
 	drv->p = NULL;
 out_put_bus:
 	bus_put(bus);
-- 
2.14.1