lkml.org 
[lkml]   [2017]   [Aug]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] driver core: bus: Fix a potential double free
Date
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>
---
I have left the 'drv->p = NULL' even if it looks useless to me. It does not
hurt. I have also left a comment to explain why we do not free 'drv->p'
explicitly before zeroing this pointer.
---
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);
--
2.11.0
\
 
 \ /
  Last update: 2017-08-29 21:27    [W:0.048 / U:0.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site