rtnetlink: call ->dellink on failure when ->newlink exists
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>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 5be499b..ab293a3 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2162,7 +2162,14 @@
}
err = rtnl_configure_link(dev, ifm);
if (err < 0) {
- unregister_netdevice(dev);
+ if (ops->newlink) {
+ LIST_HEAD(list_kill);
+
+ ops->dellink(dev, &list_kill);
+ unregister_netdevice_many(&list_kill);
+ } else {
+ unregister_netdevice(dev);
+ }
goto out;
}