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).
In macvtap_device_event it also avoids cleaning up in NETDEV_UNREGISTER
if NETDEV_REGISTER had previously failed.
Signed-off-by: Francesco Ruggeri <frugg...@arista.com>
---
drivers/net/macvlan.c | 10 ++++------
drivers/net/macvtap.c | 2 ++
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 2bcf1f3..cb01023 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;
}
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 95394ed..e770221 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -1303,6 +1303,8 @@ static int macvtap_device_event(struct notifier_block
*unused,
}
break;
case NETDEV_UNREGISTER:
+ if (vlan->minor == 0)
+ break;
devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
device_destroy(macvtap_class, devt);
macvtap_free_minor(vlan);
--
1.8.1.4
