From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933158Ab3E1VZ0 (ORCPT ); Tue, 28 May 2013 17:25:26 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59745 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933076Ab3E1VZX (ORCPT ); Tue, 28 May 2013 17:25:23 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Stephen Hemminger , "David S. Miller" , Kamal Mostafa Subject: [PATCH 67/78] bridge: fix race with topology change timer Date: Tue, 28 May 2013 14:20:16 -0700 Message-Id: <1369776027-17859-68-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1369776027-17859-1-git-send-email-kamal@canonical.com> References: <1369776027-17859-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: stephen hemminger [ Upstream commit 83401eb4990ff6af55aeed8f49681558544192e6 ] A bridge should only send topology change notice if it is not the root bridge. It is possible for message age timer to elect itself as a new root bridge, and still have a topology change timer running but waiting for bridge lock on other CPU. Solve the race by checking if we are root bridge before continuing. This was the root cause of the cases where br_send_tcn_bpdu would OOPS. Reported-by: JerryKang Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- net/bridge/br_stp_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bridge/br_stp_timer.c b/net/bridge/br_stp_timer.c index c3530a8..950663d 100644 --- a/net/bridge/br_stp_timer.c +++ b/net/bridge/br_stp_timer.c @@ -107,7 +107,7 @@ static void br_tcn_timer_expired(unsigned long arg) br_debug(br, "tcn timer expired\n"); spin_lock(&br->lock); - if (br->dev->flags & IFF_UP) { + if (!br_is_root_bridge(br) && (br->dev->flags & IFF_UP)) { br_transmit_tcn(br); mod_timer(&br->tcn_timer,jiffies + br->bridge_hello_time); -- 1.8.1.2