From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934485Ab3DGWzr (ORCPT ); Sun, 7 Apr 2013 18:55:47 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46308 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758909Ab3DGWzq (ORCPT ); Sun, 7 Apr 2013 18:55:46 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Eric Dumazet" , "Patrick McHardy" , "David S. Miller" , "Cong Wang" Date: Sun, 07 Apr 2013 23:45:42 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [56/74] 8021q: fix a potential use-after-free In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:b4b3:7e2a:e2d0:3478 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.43-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Cong Wang [ Upstream commit 4a7df340ed1bac190c124c1601bfc10cde9fb4fb ] vlan_vid_del() could possibly free ->vlan_info after a RCU grace period, however, we may still refer to the freed memory area by 'grp' pointer. Found by code inspection. This patch moves vlan_vid_del() as behind as possible. Cc: Patrick McHardy Cc: "David S. Miller" Signed-off-by: Cong Wang Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/8021q/vlan.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 5471628..963f285 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -110,13 +110,6 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head) grp = rtnl_dereference(real_dev->vlgrp); BUG_ON(!grp); - /* Take it out of our own structures, but be sure to interlock with - * HW accelerating devices or SW vlan input packet processing if - * VLAN is not 0 (leave it there for 802.1p). - */ - if (vlan_id && (real_dev->features & NETIF_F_HW_VLAN_FILTER)) - ops->ndo_vlan_rx_kill_vid(real_dev, vlan_id); - grp->nr_vlans--; if (vlan->flags & VLAN_FLAG_GVRP) @@ -139,6 +132,13 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head) call_rcu(&grp->rcu, vlan_rcu_free); } + /* Take it out of our own structures, but be sure to interlock with + * HW accelerating devices or SW vlan input packet processing if + * VLAN is not 0 (leave it there for 802.1p). + */ + if (vlan_id && (real_dev->features & NETIF_F_HW_VLAN_FILTER)) + ops->ndo_vlan_rx_kill_vid(real_dev, vlan_id); + /* Get rid of the vlan's reference to real_dev */ dev_put(real_dev); }