Commit 9a4b2410 authored by Shiraz Saleem's avatar Shiraz Saleem Committed by Jason Gunthorpe
Browse files

i40iw: Do an RCU lookup in i40iw_add_ipv4_addr 

The in_dev_for_each_ifa_rtnl() iterator in i40iw_add_ipv4_addr requires
that the rtnl lock be held. But the rtnl_trylock/unlock scheme in this
function does not guarantee it.

Replace the rtnl locking with an RCU lookup using
in_dev_for_each_ifa_rcu()

Fixes: 8e06af71 ("i40iw: add main, hdr, status")
Link: https://lore.kernel.org/r/20200204223840.2151-1-shiraz.saleem@intel.com


Signed-off-by: default avatarShiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent d7e2d343

drivers/infiniband/hw/i40iw/i40iw_main.c

+6 −12
Original line number Diff line number Diff line
@@ -1212,22 +1212,19 @@ static void i40iw_add_ipv4_addr(struct i40iw_device *iwdev) 
{

	struct net_device *dev;

	struct in_device *idev;

	bool got_lock = true;

	u32 ip_addr;



	if (!rtnl_trylock())

		got_lock = false;



	for_each_netdev(&init_net, dev) {

	rcu_read_lock();

	for_each_netdev_rcu(&init_net, dev) {

		if ((((rdma_vlan_dev_vlan_id(dev) < 0xFFFF) &&

		      (rdma_vlan_dev_real_dev(dev) == iwdev->netdev)) ||

		    (dev == iwdev->netdev)) && (dev->flags & IFF_UP)) {

		    (dev == iwdev->netdev)) && (READ_ONCE(dev->flags) & IFF_UP)) {

			const struct in_ifaddr *ifa;



			idev = in_dev_get(dev);

			idev = __in_dev_get_rcu(dev);

			if (!idev)

				continue;

			in_dev_for_each_ifa_rtnl(ifa, idev) {

			in_dev_for_each_ifa_rcu(ifa, idev) {

				i40iw_debug(&iwdev->sc_dev, I40IW_DEBUG_CM,

					    "IP=%pI4, vlan_id=%d, MAC=%pM\n", &ifa->ifa_address,

					     rdma_vlan_dev_vlan_id(dev), dev->dev_addr);
@@ -1239,12 +1236,9 @@ static void i40iw_add_ipv4_addr(struct i40iw_device *iwdev) 
						       true,

						       I40IW_ARP_ADD);

			}



			in_dev_put(idev);

		}

	}

	if (got_lock)

		rtnl_unlock();

	rcu_read_unlock();

}



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