[PATCH 3.2 33/61] driver core: bus: Fix a potential double free

From: Ben Hutchings
Date: Tue Nov 21 2017 - 21:59:52 EST

3.2.96-rc1 review patch. If anyone has any objections, please let me know.


From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

commit 0f9b011d3321ca1079c7a46c18cb1956fbdb7bcb upstream.

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@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
drivers/base/bus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -684,7 +684,7 @@ int bus_add_driver(struct device_driver

- kfree(drv->p);
+ /* drv->p is freed in driver_release() */
drv->p = NULL;