From patchwork Mon Feb 18 12:45:30 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikolay Aleksandrov X-Patchwork-Id: 221294 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 54B502C0ADE for ; Mon, 18 Feb 2013 23:47:59 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756192Ab3BRMrt (ORCPT ); Mon, 18 Feb 2013 07:47:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:24757 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755349Ab3BRMrs (ORCPT ); Mon, 18 Feb 2013 07:47:48 -0500 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r1IClibj011357 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 18 Feb 2013 07:47:45 -0500 Received: from boza.brq.redhat.com (dhcp-1-132.brq.redhat.com [10.34.1.132]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r1IClgu0018565; Mon, 18 Feb 2013 07:47:43 -0500 From: Nikolay Aleksandrov To: netdev@vger.kernel.org Cc: andy@greyhouse.net, fubar@us.ibm.com, davem@davemloft.net Subject: [PATCH] bonding: Fix race condition between bond_enslave() and bond_3ad_update_lacp_rate() Date: Mon, 18 Feb 2013 13:45:30 +0100 Message-Id: <1361191530-7616-1-git-send-email-nikolay@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org port->slave can be NULL since it's being initialized in bond_enslave thus dereferencing a NULL pointer in bond_3ad_update_lacp_rate() Also fix a minor bug, which could cause a port not to have AD_STATE_LACP_TIMEOUT since there's no sync between bond_3ad_update_lacp_rate() and bond_3ad_bind_slave(), by changing the read_lock to a write_lock_bh in bond_3ad_update_lacp_rate(). Signed-off-by: Nikolay Aleksandrov --- drivers/net/bonding/bond_3ad.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/bonding/bond_3ad.c b/drivers/net/bonding/bond_3ad.c index a030e63..1720742 100644 --- a/drivers/net/bonding/bond_3ad.c +++ b/drivers/net/bonding/bond_3ad.c @@ -2494,11 +2494,13 @@ void bond_3ad_update_lacp_rate(struct bonding *bond) struct port *port = NULL; int lacp_fast; - read_lock(&bond->lock); + write_lock_bh(&bond->lock); lacp_fast = bond->params.lacp_fast; bond_for_each_slave(bond, slave, i) { port = &(SLAVE_AD_INFO(slave).port); + if (port->slave == NULL) + continue; __get_state_machine_lock(port); if (lacp_fast) port->actor_oper_port_state |= AD_STATE_LACP_TIMEOUT; @@ -2507,5 +2509,5 @@ void bond_3ad_update_lacp_rate(struct bonding *bond) __release_state_machine_lock(port); } - read_unlock(&bond->lock); + write_unlock_bh(&bond->lock); }