Commit 8652a96c authored Feb 13, 2015 by WANG Cong Committed by Sasha Levin Mar 14, 2015

rtnetlink: call ->dellink on failure when ->newlink exists



[ Upstream commit 7afb8886a05be68e376655539a064ec672de8a8e ]

Ignacy reported that when eth0 is down and add a vlan device
on top of it like:

  ip link add link eth0 name eth0.1 up type vlan id 1

We will get a refcount leak:

  unregister_netdevice: waiting for eth0.1 to become free. Usage count = 2

The problem is when rtnl_configure_link() fails in rtnl_newlink(),
we simply call unregister_device(), but for stacked device like vlan,
we almost do nothing when we unregister the upper device, more work
is done when we unregister the lower device, so call its ->dellink().

Reported-by: Ignacy Gawedzki <ignacy.gawedzki@green-communications.fr>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent 677aa4a2

net/core/rtnetlink.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -2099,8 +2099,16 @@ replay:
		}
		}
		err = rtnl_configure_link(dev, ifm);
		if (err < 0)
		if (err < 0) {
		if (ops->newlink) {
		LIST_HEAD(list_kill);

		ops->dellink(dev, &list_kill);
		unregister_netdevice_many(&list_kill);
		} else {
		unregister_netdevice(dev);
		}
		}
		out:
		put_net(dest_net);
		return err;