bridge: fix bridge netlink RCU usage (2f56f6be) · Commits · 戴 / test

When the STP timer fires, it can call br_ifinfo_notify(), which in turn ends up in the new br_get_link_af_size(). This function is annotated to be using RTNL locking, which clearly isn't the case here, and thus lockdep warns: =============================== [ INFO: suspicious RCU usage. ] 3.19.0+ #569 Not tainted ------------------------------- net/bridge/br_private.h:204 suspicious rcu_dereference_protected() usage! Fix this by doing RCU locking here. Fixes: ("bridge: add vlan info to bridge setlink and dellink notification messages") Signed-off-by:

Johannes Berg <johannes.berg@intel.com> Acked-by:

Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/bridge/br_netlink.c

+8 −6

Original line number	Original line	Diff line number	Diff line
	@@ -81,17 +81,19 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
	struct net_port_vlans *pv;		struct net_port_vlans *pv;
	int num_vlan_infos;		int num_vlan_infos;

			rcu_read_lock();
	if (br_port_exists(dev))		if (br_port_exists(dev))
	pv = nbp_get_vlan_info(br_port_get_rtnl(dev));		pv = nbp_get_vlan_info(br_port_get_rcu(dev));
	else if (dev->priv_flags & IFF_EBRIDGE)		else if (dev->priv_flags & IFF_EBRIDGE)
	pv = br_get_vlan_info((struct net_bridge *)netdev_priv(dev));		pv = br_get_vlan_info((struct net_bridge *)netdev_priv(dev));
	else		else
	return 0;		pv = NULL;
			if (pv)
	if (!pv)
	return 0;

	num_vlan_infos = br_get_num_vlan_infos(pv, filter_mask);		num_vlan_infos = br_get_num_vlan_infos(pv, filter_mask);
			else
			num_vlan_infos = 0;
			rcu_read_unlock();

	if (!num_vlan_infos)		if (!num_vlan_infos)
	return 0;		return 0;

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