From: Kaixin Wang kxwang23@m.fudan.edu.cn

stable inclusion from stable-v5.10.227 commit b650189687822b705711f0567a65a164a314d8df 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=...

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[ 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 4c6eb61a6ac6..ad09946100b5 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"); }