From 963ad94853000ab100f5ff19eea80095660d41b4 Mon Sep 17 00:00:00 2001 From: Nikolay Aleksandrov Date: Wed, 22 Jul 2015 13:03:40 +0200 Subject: [PATCH] bridge: netlink: fix slave_changelink/br_setport race conditions 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 --- 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 364bdc98bd9b..3da5525eb8a2 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -693,9 +693,17 @@ 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, -- 2.39.5