From: Kaixin Wang <kxwang23@m.fudan.edu.cn> 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=... -------------------------------- [ 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@m.fudan.edu.cn> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Jon Mason <jdmason@kudzu.us> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- 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 d6bbcc7b5b90..0a94c634ddc2 100644 --- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c +++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c @@ -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"); } -- 2.25.1