macvlan: fix failure during registration v3 (30837960) · Commits · 戴 / test

If macvlan_common_newlink fails in register_netdevice after macvlan_init then it decrements port->count twice, first in macvlan_uninit (from register_netdevice or rollback_registered) and then again in macvlan_common_newlink. A similar problem may exist in the ipvlan driver. This patch consolidates modifications to port->count into macvlan_init and macvlan_uninit (thanks to Eric Biederman for suggesting this approach). v3: remove macvtap specific bits. Signed-off-by:

Francesco Ruggeri <fruggeri@arista.com> Acked-by:

"Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/macvlan.c

+4 −6

Original line number	Diff line number	Diff line
		@@ -795,6 +795,7 @@ static int macvlan_init(struct net_device *dev)
		{
		struct macvlan_dev *vlan = netdev_priv(dev);
		const struct net_device *lowerdev = vlan->lowerdev;
		struct macvlan_port *port = vlan->port;

		dev->state = (dev->state & ~MACVLAN_STATE_MASK) \|
		(lowerdev->state & MACVLAN_STATE_MASK);
		@@ -812,6 +813,8 @@ static int macvlan_init(struct net_device *dev)
		if (!vlan->pcpu_stats)
		return -ENOMEM;

		port->count += 1;

		return 0;
		}

		@@ -1312,10 +1315,9 @@ int macvlan_common_newlink(struct net src_net, struct net_device dev,
		return err;
		}

		port->count += 1;
		err = register_netdevice(dev);
		if (err < 0)
		goto destroy_port;
		return err;

		dev->priv_flags \|= IFF_MACVLAN;
		err = netdev_upper_dev_link(lowerdev, dev);
		@@ -1330,10 +1332,6 @@ int macvlan_common_newlink(struct net src_net, struct net_device dev,

		unregister_netdev:
		unregister_netdevice(dev);
		destroy_port:
		port->count -= 1;
		if (!port->count)
		macvlan_port_destroy(lowerdev);

		return err;
		}

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