From mboxrd@z Thu Jan 1 00:00:00 1970 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 DC86AC433FE for ; Sat, 19 Nov 2022 03:35:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229687AbiKSDfc (ORCPT ); Fri, 18 Nov 2022 22:35:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbiKSDf3 (ORCPT ); Fri, 18 Nov 2022 22:35:29 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6367BBB9C2 for ; Fri, 18 Nov 2022 19:35:27 -0800 (PST) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NDfMV5dLkzqSQk; Sat, 19 Nov 2022 11:31:34 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Sat, 19 Nov 2022 11:35:25 +0800 Received: from octopus.huawei.com (10.67.174.191) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Sat, 19 Nov 2022 11:35:25 +0800 From: Wang Weiyang To: , , , , , , , CC: Subject: [PATCH v2] rapidio: fix possible UAF when kfifo_alloc() fails Date: Sat, 19 Nov 2022 12:03:35 +0800 Message-ID: <20221119040335.46794-1-wangweiyang2@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.174.191] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If kfifo_alloc() fails in mport_cdev_open(), goto err_fifo and just free priv. But priv is still in the chdev->file_list, then list traversal may cause UAF. This fixes the following smatch warning: drivers/rapidio/devices/rio_mport_cdev.c:1930 mport_cdev_open() warn: '&priv->list' not removed from list Fixes: e8de370188d0 ("rapidio: add mport char device driver") Signed-off-by: Wang Weiyang --- Changes in v2: - Avoid adding the new instance onto the list until the new instance has been fully initialized. drivers/rapidio/devices/rio_mport_cdev.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c index 3cc83997a1f8..86b28c4cd906 100644 --- a/drivers/rapidio/devices/rio_mport_cdev.c +++ b/drivers/rapidio/devices/rio_mport_cdev.c @@ -1904,10 +1904,6 @@ static int mport_cdev_open(struct inode *inode, struct file *filp) priv->md = chdev; - mutex_lock(&chdev->file_mutex); - list_add_tail(&priv->list, &chdev->file_list); - mutex_unlock(&chdev->file_mutex); - INIT_LIST_HEAD(&priv->db_filters); INIT_LIST_HEAD(&priv->pw_filters); spin_lock_init(&priv->fifo_lock); @@ -1920,6 +1916,9 @@ static int mport_cdev_open(struct inode *inode, struct file *filp) ret = -ENOMEM; goto err_fifo; } + mutex_lock(&chdev->file_mutex); + list_add_tail(&priv->list, &chdev->file_list); + mutex_unlock(&chdev->file_mutex); #ifdef CONFIG_RAPIDIO_DMA_ENGINE INIT_LIST_HEAD(&priv->async_list); -- 2.17.1