This is a note to let you know that I've just added the patch titled
ntb: ntb_hw_switchtec: Fix use after free vulnerability in switchtec_ntb_remove due to race condition
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ntb-ntb_hw_switchtec-fix-use-after-free-vulnerabilit.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 295da47bd526622ceb38e52daf09c87bd74d7909
Author: Kaixin Wang <kxwang23@xxxxxxxxxxxxxx>
Date: Tue Sep 10 01:20:07 2024 +0800
ntb: ntb_hw_switchtec: Fix use after free vulnerability in switchtec_ntb_remove due to race condition
[ 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>
diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index 4c6eb61a6ac62..ad09946100b56 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -1558,6 +1558,7 @@ 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");
}
