[PATCH] driver: base: fix UAF when driver_attach failed

From: Schspa Shi
Date: Wed May 11 2022 - 08:43:53 EST


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@xxxxxxxxx>
---
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 97936ec49bde..7ca47e5b3c1f 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -617,7 +617,7 @@ 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);

@@ -644,6 +644,8 @@ 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() */
--
2.29.0