Commit 963ad948 authored Jul 22, 2015 by Nikolay Aleksandrov Committed by David S. Miller Jul 26, 2015

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 <nikolay@cumulusnetworks.com>
Fixes: 3ac636b8 ("bridge: implement rtnl_link_ops->slave_changelink")
Reviewed-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 48516438

net/bridge/br_netlink.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -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,

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