From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:49113 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932133AbbH0WNZ (ORCPT ); Thu, 27 Aug 2015 18:13:25 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Nikolay Aleksandrov , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 114/130] bridge: netlink: fix slave_changelink/br_setport race conditions Date: Thu, 27 Aug 2015 15:11:45 -0700 Message-Id: <1440713521-5906-115-git-send-email-kamal@canonical.com> In-Reply-To: <1440713521-5906-1-git-send-email-kamal@canonical.com> References: <1440713521-5906-1-git-send-email-kamal@canonical.com> Sender: stable-owner@vger.kernel.org List-ID: 3.19.8-ckt6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikolay Aleksandrov commit 963ad94853000ab100f5ff19eea80095660d41b4 upstream. Since slave_changelink support was added there have been a few race conditions when using br_setport() since some of the port functions it uses require the bridge lock. It is very easy to trigger a lockup due to some internal spin_lock() usage without bh disabled, also it's possible to get the bridge into an inconsistent state. Signed-off-by: Nikolay Aleksandrov Fixes: 3ac636b8591c ("bridge: implement rtnl_link_ops->slave_changelink") Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- net/bridge/br_netlink.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c index 9f5eb55..36e56a9 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -466,9 +466,17 @@ static int br_port_slave_changelink(struct net_device *brdev, struct nlattr *tb[], struct nlattr *data[]) { + struct net_bridge *br = netdev_priv(brdev); + int ret; + if (!data) return 0; - return br_setport(br_port_get_rtnl(dev), data); + + spin_lock_bh(&br->lock); + ret = br_setport(br_port_get_rtnl(dev), data); + spin_unlock_bh(&br->lock); + + return ret; } static int br_port_fill_slave_info(struct sk_buff *skb, -- 1.9.1