[PATCH] usb: roles: fix a potential use after free

From: Wen Yang
Date: Sun Nov 24 2019 - 09:23:34 EST


Free the sw structure only after we are done using it.
This patch just moves the put_device() down a bit to avoid the
use after free.

Fixes: 5c54fcac9a9d ("usb: roles: Take care of driver module reference counting")
Signed-off-by: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx>
Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
drivers/usb/roles/class.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index 8273126..63a00ff 100644
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -169,8 +169,8 @@ struct usb_role_switch *fwnode_usb_role_switch_get(struct fwnode_handle *fwnode)
void usb_role_switch_put(struct usb_role_switch *sw)
{
if (!IS_ERR_OR_NULL(sw)) {
- put_device(&sw->dev);
module_put(sw->dev.parent->driver->owner);
+ put_device(&sw->dev);
}
}
EXPORT_SYMBOL_GPL(usb_role_switch_put);
--
1.8.3.1