Commit 0e0eee24 authored Feb 11, 2014 by Cong Wang Committed by David S. Miller Feb 13, 2014

net: correct error path in rtnl_newlink()



I saw the following BUG when ->newlink() fails in rtnl_newlink():

[   40.240058] kernel BUG at net/core/dev.c:6438!

this is due to free_netdev() is not supposed to be called before
netdev is completely unregistered, therefore it is not correct
to call free_netdev() here, at least for ops->newlink!=NULL case,
many drivers call it in ->destructor so that rtnl_unlock() will
take care of it, we probably don't need to do anything here.

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent da37705c

net/core/rtnetlink.c

+12 −7

Original line number	Diff line number	Diff line
		@@ -1963,16 +1963,21 @@ static int rtnl_newlink(struct sk_buff skb, struct nlmsghdr nlh)

		dev->ifindex = ifm->ifi_index;

		if (ops->newlink)
		if (ops->newlink) {
		err = ops->newlink(net, dev, tb, data);
		else
		/* Drivers should call free_netdev() in ->destructor
		* and unregister it on failure so that device could be
		* finally freed in rtnl_unlock.
		*/
		if (err < 0)
		goto out;
		} else {
		err = register_netdevice(dev);

		if (err < 0) {
		free_netdev(dev);
		goto out;
		}

		}
		err = rtnl_configure_link(dev, ifm);
		if (err < 0)
		unregister_netdevice(dev);