From 8709c323091be019f76a49cf783052a5636aca85 Mon Sep 17 00:00:00 2001 From: Wenchao Hao Date: Wed, 9 Mar 2022 20:57:59 -0500 Subject: scsi: libiscsi: Teardown iscsi_cls_conn gracefully Commit 1b8d0300a3e9 ("scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown()") fixed an UAF in iscsi_conn_get_param() and introduced 2 tmp_xxx varibles. We can gracefully fix this UAF with the help of device_del(). Calling iscsi_remove_conn() at the beginning of iscsi_conn_teardown would make userspace unable to see iscsi_cls_conn. This way we we can free memory safely. Remove iscsi_destroy_conn() since it is no longer used. Link: https://lore.kernel.org/r/20220310015759.3296841-4-haowenchao@huawei.com Reviewed-by: Mike Christie Signed-off-by: Wenchao Hao Signed-off-by: Wu Bo Signed-off-by: Martin K. Petersen --- drivers/scsi/scsi_transport_iscsi.c | 27 +++++---------------------- 1 file changed, 5 insertions(+), 22 deletions(-) (limited to 'drivers/scsi/scsi_transport_iscsi.c') diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index 803b6b06d83b..27951ea05dd4 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2137,7 +2137,11 @@ static int iscsi_iter_destroy_conn_fn(struct device *dev, void *data) { if (!iscsi_is_conn_dev(dev)) return 0; - return iscsi_destroy_conn(iscsi_dev_to_conn(dev)); + + iscsi_remove_conn(iscsi_dev_to_conn(dev)); + iscsi_put_conn(iscsi_dev_to_conn(dev)); + + return 0; } void iscsi_remove_session(struct iscsi_cls_session *session) @@ -2414,27 +2418,6 @@ void iscsi_remove_conn(struct iscsi_cls_conn *conn) } EXPORT_SYMBOL_GPL(iscsi_remove_conn); -/** - * iscsi_destroy_conn - destroy iscsi class connection - * @conn: iscsi cls session - * - * This can be called from a LLD or iscsi_transport. - */ -int iscsi_destroy_conn(struct iscsi_cls_conn *conn) -{ - unsigned long flags; - - spin_lock_irqsave(&connlock, flags); - list_del(&conn->conn_list); - spin_unlock_irqrestore(&connlock, flags); - - transport_unregister_device(&conn->dev); - ISCSI_DBG_TRANS_CONN(conn, "Completing conn destruction\n"); - device_unregister(&conn->dev); - return 0; -} -EXPORT_SYMBOL_GPL(iscsi_destroy_conn); - void iscsi_put_conn(struct iscsi_cls_conn *conn) { put_device(&conn->dev); -- cgit v1.2.3-59-g8ed1b