From patchwork Thu Mar 10 01:57:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wenchao Hao X-Patchwork-Id: 12775038 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5E97C433EF for ; Wed, 9 Mar 2022 12:48:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232841AbiCIMtF (ORCPT ); Wed, 9 Mar 2022 07:49:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232818AbiCIMsp (ORCPT ); Wed, 9 Mar 2022 07:48:45 -0500 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8AF827B1F; Wed, 9 Mar 2022 04:47:45 -0800 (PST) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4KDBgH5NJVz1GCK2; Wed, 9 Mar 2022 20:42:51 +0800 (CST) Received: from dggpemm500017.china.huawei.com (7.185.36.178) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 9 Mar 2022 20:47:40 +0800 Received: from huawei.com (10.175.101.6) by dggpemm500017.china.huawei.com (7.185.36.178) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 9 Mar 2022 20:47:40 +0800 From: Wenchao Hao To: Mike Christie , Lee Duncan , Chris Leech , "James E . J . Bottomley" , "Martin K . Petersen" , , , CC: Wu Bo , Zhiqiang Liu , , Wenchao Hao Subject: [PATCH v3 3/3] scsi:libiscsi: teradown iscsi_cls_conn gracefully Date: Wed, 9 Mar 2022 20:57:59 -0500 Message-ID: <20220310015759.3296841-4-haowenchao@huawei.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220310015759.3296841-1-haowenchao@huawei.com> References: <20220310015759.3296841-1-haowenchao@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500017.china.huawei.com (7.185.36.178) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org 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, the implement looks ugly. We can fix this UAF with the help of device_del() gracefully. Call iscsi_remove_conn() at the beginning of iscsi_conn_teardown would make userspace unable to see iscsi_cls_conn any more, then we can free memory safely. And remove iscsi_destroy_conn() by hand since it is not used now. Signed-off-by: Wenchao Hao Signed-off-by: Wu Bo --- drivers/scsi/libiscsi.c | 10 +++++----- drivers/scsi/scsi_transport_iscsi.c | 27 +++++---------------------- include/scsi/scsi_transport_iscsi.h | 1 - 3 files changed, 10 insertions(+), 28 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 38e68b449c08..da583a39b307 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -3109,8 +3109,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) { struct iscsi_conn *conn = cls_conn->dd_data; struct iscsi_session *session = conn->session; - char *tmp_persistent_address = conn->persistent_address; - char *tmp_local_ipaddr = conn->local_ipaddr; + + iscsi_remove_conn(cls_conn); del_timer_sync(&conn->transport_timer); @@ -3132,6 +3132,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) spin_lock_bh(&session->frwd_lock); free_pages((unsigned long) conn->data, get_order(ISCSI_DEF_MAX_RECV_SEG_LEN)); + kfree(conn->persistent_address); + kfree(conn->local_ipaddr); /* regular RX path uses back_lock */ spin_lock_bh(&session->back_lock); kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task, @@ -3142,9 +3144,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) spin_unlock_bh(&session->frwd_lock); mutex_unlock(&session->eh_mutex); - iscsi_destroy_conn(cls_conn); - kfree(tmp_persistent_address); - kfree(tmp_local_ipaddr); + iscsi_put_conn(cls_conn); } EXPORT_SYMBOL_GPL(iscsi_conn_teardown); diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index fc33000a6af9..d0f996d14782 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -2165,7 +2165,11 @@ 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) @@ -2437,27 +2441,6 @@ 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); diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h index 4af6768e8195..aedbc4488149 100644 --- a/include/scsi/scsi_transport_iscsi.h +++ b/include/scsi/scsi_transport_iscsi.h @@ -447,7 +447,6 @@ extern int iscsi_add_conn(struct iscsi_cls_conn *conn); extern void iscsi_remove_conn(struct iscsi_cls_conn *conn); extern void iscsi_put_conn(struct iscsi_cls_conn *conn); extern void iscsi_get_conn(struct iscsi_cls_conn *conn); -extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn); extern void iscsi_unblock_session(struct iscsi_cls_session *session); extern void iscsi_block_session(struct iscsi_cls_session *session); extern int iscsi_scan_finished(struct Scsi_Host *shost, unsigned long time);