5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kaixin Wang <kxwang23@xxxxxxxxxxxxxx>
[ Upstream commit e51aded92d42784313ba16c12f4f88cc4f973bbb ]
In the switchtec_ntb_add function, it can call switchtec_ntb_init_sndev
function, then &sndev->check_link_status_work is bound with
check_link_status_work. switchtec_ntb_link_notification may be called
to start the work.
If we remove the module which will call switchtec_ntb_remove to make
cleanup, it will free sndev through kfree(sndev), while the work
mentioned above will be used. The sequence of operations that may lead
to a UAF bug is as follows:
CPU0 CPU1
| check_link_status_work
switchtec_ntb_remove |
kfree(sndev); |
| if (sndev->link_force_down)
| // use sndev
Fix it by ensuring that the work is canceled before proceeding with
the cleanup in switchtec_ntb_remove.
Signed-off-by: Kaixin Wang <kxwang23@xxxxxxxxxxxxxx>
Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Signed-off-by: Jon Mason <jdmason@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index ec9cb6c81edae..759248415b5c2 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -1556,6 +1556,7 @@ static void switchtec_ntb_remove(struct device *dev,
switchtec_ntb_deinit_db_msg_irq(sndev);
switchtec_ntb_deinit_shared_mw(sndev);
switchtec_ntb_deinit_crosslink(sndev);
+ cancel_work_sync(&sndev->check_link_status_work);
kfree(sndev);
dev_info(dev, "ntb device unregistered\n");
}
--
2.43.0
