Commit b1aec41c authored by Kaixin Wang's avatar Kaixin Wang Committed by Yongqiang Liu
Browse files

ntb: ntb_hw_switchtec: Fix use after free vulnerability in... 

ntb: ntb_hw_switchtec: Fix use after free vulnerability in switchtec_ntb_remove due to race condition

stable inclusion
from stable-v6.6.57
commit fa840ba4bd9f3bad7f104e5b32028ee73af8b3dd
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAYRF0
CVE: CVE-2024-50059

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fa840ba4bd9f3bad7f104e5b32028ee73af8b3dd



--------------------------------

[ 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: default avatarKaixin Wang <kxwang23@m.fudan.edu.cn>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarYongqiang Liu <liuyongqiang13@huawei.com>
parent ab348dfd

drivers/ntb/hw/mscc/ntb_hw_switchtec.c

+1 −0
Original line number Diff line number Diff line
@@ -1554,6 +1554,7 @@ 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");

}