From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59692 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933362AbbIZVSN (ORCPT ); Sat, 26 Sep 2015 17:18:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nikolay Aleksandrov , Jiri Pirko , "David S. Miller" Subject: [PATCH 4.1 142/159] bridge: netlink: fix slave_changelink/br_setport race conditions Date: Sat, 26 Sep 2015 13:56:28 -0700 Message-Id: <20150926205321.603089405@linuxfoundation.org> In-Reply-To: <20150926205313.363686083@linuxfoundation.org> References: <20150926205313.363686083@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: stable-owner@vger.kernel.org List-ID: 4.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikolay Aleksandrov [ Upstream commit 963ad94853000ab100f5ff19eea80095660d41b4 ] 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: Greg Kroah-Hartman --- net/bridge/br_netlink.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -711,9 +711,17 @@ static int br_port_slave_changelink(stru 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,