From patchwork Wed Mar 2 16:30:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Wunderlich X-Patchwork-Id: 12766306 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D95BC433F5 for ; Wed, 2 Mar 2022 16:40:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243314AbiCBQkt (ORCPT ); Wed, 2 Mar 2022 11:40:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230372AbiCBQks (ORCPT ); Wed, 2 Mar 2022 11:40:48 -0500 Received: from simonwunderlich.de (simonwunderlich.de [23.88.38.48]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDEA5CF38B for ; Wed, 2 Mar 2022 08:40:03 -0800 (PST) Received: from kero.packetmixer.de (p200300C597470fc0d439fbe5C3508408.dip0.t-ipconnect.de [IPv6:2003:c5:9747:fc0:d439:fbe5:c350:8408]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simonwunderlich.de (Postfix) with ESMTPSA id 3B1D6FA1EC; Wed, 2 Mar 2022 17:30:52 +0100 (CET) From: Simon Wunderlich To: davem@davemloft.net, kuba@kernel.org Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, Sven Eckelmann , Simon Wunderlich Subject: [PATCH 1/3] batman-adv: Request iflink once in batadv-on-batadv check Date: Wed, 2 Mar 2022 17:30:47 +0100 Message-Id: <20220302163049.101957-2-sw@simonwunderlich.de> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220302163049.101957-1-sw@simonwunderlich.de> References: <20220302163049.101957-1-sw@simonwunderlich.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Sven Eckelmann There is no need to call dev_get_iflink multiple times for the same net_device in batadv_is_on_batman_iface. And since some of the .ndo_get_iflink callbacks are dynamic (for example via RCUs like in vxcan_get_iflink), it could easily happen that the returned values are not stable. The pre-checks before __dev_get_by_index are then of course bogus. Fixes: b7eddd0b3950 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface") Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/hard-interface.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index 8a2b78f9c4b2..35aa1122043b 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -149,22 +149,23 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev) struct net *net = dev_net(net_dev); struct net_device *parent_dev; struct net *parent_net; + int iflink; bool ret; /* check if this is a batman-adv mesh interface */ if (batadv_softif_is_valid(net_dev)) return true; + iflink = dev_get_iflink(net_dev); + /* no more parents..stop recursion */ - if (dev_get_iflink(net_dev) == 0 || - dev_get_iflink(net_dev) == net_dev->ifindex) + if (iflink == 0 || iflink == net_dev->ifindex) return false; parent_net = batadv_getlink_net(net_dev, net); /* recurse over the parent device */ - parent_dev = __dev_get_by_index((struct net *)parent_net, - dev_get_iflink(net_dev)); + parent_dev = __dev_get_by_index((struct net *)parent_net, iflink); /* if we got a NULL parent_dev there is something broken.. */ if (!parent_dev) { pr_err("Cannot find parent device\n");