Commit a6ca5f1d authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
Browse files

[MACVLAN]: Prevent nesting macvlan devices 



Don't allow to nest macvlan devices since it will cause lockdep
warnings and isn't really useful for anything.

Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0fe1e567

drivers/net/macvlan.c

+7 −0
Original line number Diff line number Diff line
@@ -384,6 +384,13 @@ static int macvlan_newlink(struct net_device *dev, 
	if (lowerdev == NULL)

		return -ENODEV;



	/* Don't allow macvlans on top of other macvlans - its not really

	 * wrong, but lockdep can't handle it and its not useful for anything

	 * you couldn't do directly on top of the real device.

	 */

	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops)

		return -ENODEV;



	if (!tb[IFLA_MTU])

		dev->mtu = lowerdev->mtu;

	else if (dev->mtu > lowerdev->mtu)