[PATCH 5.4 317/411] driver: base: fix UAF when driver_attach failed

Greg Kroah-Hartman
2022-06-13T11:39:50Z

From: Schspa Shi <schspa@gmail.com>

[ Upstream commit 310862e574001a97ad02272bac0fd13f75f42a27 ]

When driver_attach(drv); failed, the driver_private will be freed.
But it has been added to the bus, which caused a UAF.

To fix it, we need to delete it from the bus when failed.

Fixes: 190888ac01d0 ("driver core: fix possible missing of device probe")
Signed-off-by: Schspa Shi <schspa@gmail.com>
Link: https://lore.kernel.org/r/20220513112444.45112-1-schspa@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/base/bus.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index a1d1e8256324..7d7d28f498ed 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -620,7 +620,7 @@ int bus_add_driver(struct device_driver *drv)
if (drv->bus->p->drivers_autoprobe) {
error = driver_attach(drv);
if (error)
- goto out_unregister;
+ goto out_del_list;
}
module_add_driver(drv->owner, drv);

@@ -647,6 +647,8 @@ int bus_add_driver(struct device_driver *drv)

return 0;

+out_del_list:
+ klist_del(&priv->knode_bus);
out_unregister:
kobject_put(&priv->kobj);
/* drv->p is freed in driver_release() */
--
2.35.1