From 308379607548524b8d86dbf20134681024935e0b Mon Sep 17 00:00:00 2001 From: Francesco Ruggeri Date: Sat, 23 Apr 2016 15:03:32 -0700 Subject: [PATCH] macvlan: fix failure during registration v3 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 Acked-by: "Eric W. Biederman" Signed-off-by: David S. Miller --- drivers/net/macvlan.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index 2bcf1f321bea..cb01023eab41 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -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; } -- 2.20.1