From patchwork Fri Jan 15 14:30:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 12023023 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C2ADC433E6 for ; Fri, 15 Jan 2021 14:32:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F22BD23877 for ; Fri, 15 Jan 2021 14:32:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732271AbhAOOb2 (ORCPT ); Fri, 15 Jan 2021 09:31:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726030AbhAOOb2 (ORCPT ); Fri, 15 Jan 2021 09:31:28 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 778D6C0613D3 for ; Fri, 15 Jan 2021 06:30:47 -0800 (PST) Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l0Q7b-0002jd-LQ; Fri, 15 Jan 2021 15:30:39 +0100 Received: from ore by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1l0Q7Z-00089T-K2; Fri, 15 Jan 2021 15:30:37 +0100 From: Oleksij Rempel To: mkl@pengutronix.de, "David S. Miller" , Jakub Kicinski , Oliver Hartkopp , Robin van der Gracht Cc: Oleksij Rempel , kernel@pengutronix.de, linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH net 2/2] net: can: j1939: fix check for valid CAN devices Date: Fri, 15 Jan 2021 15:30:36 +0100 Message-Id: <20210115143036.31275-2-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210115143036.31275-1-o.rempel@pengutronix.de> References: <20210115143036.31275-1-o.rempel@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC With the last patch a dedicated struct can_ml pointer was added to the struct netdevice to store CAN stack related private data. The data is only allocated and the pointer is only set by CAN devices. Now we use a NULL pointer check on ndev->can to check for real CAN devices. Only checking the ARPHRD via ndev->type is not sufficient, since it can be set by user space to an arbitrary value for tun/tap devices. Since the ndev->type and ndev->can are now checked early, this patch removes obsolete checks further down the call stacks. Signed-off-by: Oleksij Rempel --- net/can/j1939/main.c | 12 +++--------- net/can/j1939/socket.c | 2 +- 2 files changed, 4 insertions(+), 10 deletions(-) diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c index 62088074230d..fbc0d25046e2 100644 --- a/net/can/j1939/main.c +++ b/net/can/j1939/main.c @@ -213,9 +213,6 @@ static inline struct j1939_priv *j1939_ndev_to_priv(struct net_device *ndev) { struct can_ml_priv *can_ml_priv = ndev->can; - if (!can_ml_priv) - return NULL; - return can_ml_priv->j1939_priv; } @@ -225,9 +222,6 @@ static struct j1939_priv *j1939_priv_get_by_ndev_locked(struct net_device *ndev) lockdep_assert_held(&j1939_netdev_lock); - if (ndev->type != ARPHRD_CAN) - return NULL; - priv = j1939_ndev_to_priv(ndev); if (priv) j1939_priv_get(priv); @@ -350,13 +344,13 @@ static int j1939_netdev_notify(struct notifier_block *nb, struct net_device *ndev = netdev_notifier_info_to_dev(data); struct j1939_priv *priv; + if (ndev->type != ARPHRD_CAN || !ndev->can) + goto notify_put; + priv = j1939_priv_get_by_ndev(ndev); if (!priv) goto notify_done; - if (ndev->type != ARPHRD_CAN) - goto notify_put; - switch (msg) { case NETDEV_DOWN: j1939_cancel_active_session(priv, NULL); diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c index 8010fbc8bd29..61732e558980 100644 --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -461,7 +461,7 @@ static int j1939_sk_bind(struct socket *sock, struct sockaddr *uaddr, int len) goto out_release_sock; } - if (ndev->type != ARPHRD_CAN) { + if (ndev->type != ARPHRD_CAN || !ndev->can) { dev_put(ndev); ret = -ENODEV; goto out_release_sock;