From patchwork Wed Apr 3 07:52:40 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amerigo Wang X-Patchwork-Id: 233300 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 EA9D22C011A for ; Wed, 3 Apr 2013 18:53:08 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759775Ab3DCHxF (ORCPT ); Wed, 3 Apr 2013 03:53:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54585 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759083Ab3DCHxD (ORCPT ); Wed, 3 Apr 2013 03:53:03 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r337quZC010218 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 3 Apr 2013 03:52:57 -0400 Received: from cr0.redhat.com (vpn1-114-152.nay.redhat.com [10.66.114.152]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id r337qljw026396; Wed, 3 Apr 2013 03:52:50 -0400 From: Cong Wang To: netdev@vger.kernel.org Cc: Eric Dumazet , "David S. Miller" , David Ward , "Jorge Boncompte [DTI2]" , Cong Wang Subject: [PATCH net-next] 802: fix a possible race condition Date: Wed, 3 Apr 2013 15:52:40 +0800 Message-Id: <1364975560-6812-1-git-send-email-amwang@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Cong Wang (Resend with a better changelog) garp_pdu_queue() should ways be called with this spin lock. garp_uninit_applicant() only holds rtnl lock which is not enough here. A possible race can happen as garp_pdu_rcv() is called in BH context: garp_pdu_rcv() |->garp_pdu_parse_msg() |->garp_pdu_parse_attr() |-> garp_gid_event() Found by code inspection. Cc: Eric Dumazet Cc: "David S. Miller" Cc: David Ward Cc: "Jorge Boncompte [DTI2]" Signed-off-by: Cong Wang --- net/802/garp.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/net/802/garp.c b/net/802/garp.c index 8456f5d..5d9630a 100644 --- a/net/802/garp.c +++ b/net/802/garp.c @@ -609,8 +609,12 @@ void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl /* Delete timer and generate a final TRANSMIT_PDU event to flush out * all pending messages before the applicant is gone. */ del_timer_sync(&app->join_timer); + + spin_lock_bh(&app->lock); garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU); garp_pdu_queue(app); + spin_unlock_bh(&app->lock); + garp_queue_xmit(app); dev_mc_del(dev, appl->proto.group_address);