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: 3ac636b859 ("bridge: implement rtnl_link_ops->slave_changelink")
Reviewed-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Nikolay Aleksandrov 2015-07-22 13:03:40 +02:00 committed by David S. Miller
parent 485164381c
commit 963ad94853

View File

@ -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,