net: force a list_del() in unregister_netdevice_many()

[ Upstream commit 87757a917b0b3c0787e0563c679762152be81312 ]

unregister_netdevice_many() API is error prone and we had too
many bugs because of dangling LIST_HEAD on stacks.

See commit f87e6f4793 ("net: dont leave active on stack LIST_HEAD")

In fact, instead of making sure no caller leaves an active list_head,
just force a list_del() in the callee. No one seems to need to access
the list after unregister_netdevice_many()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric Dumazet 2014-06-06 06:44:03 -07:00 committed by Greg Kroah-Hartman
parent 9deb5f0852
commit 6a827d8a67
4 changed files with 4 additions and 4 deletions

View File

@ -961,7 +961,6 @@ static int macvlan_device_event(struct notifier_block *unused,
list_for_each_entry_safe(vlan, next, &port->vlans, list)
vlan->dev->rtnl_link_ops->dellink(vlan->dev, &list_kill);
unregister_netdevice_many(&list_kill);
list_del(&list_kill);
break;
case NETDEV_PRE_TYPE_CHANGE:
/* Forbid underlaying device to change its type. */

View File

@ -5827,6 +5827,9 @@ EXPORT_SYMBOL(unregister_netdevice_queue);
/**
* unregister_netdevice_many - unregister many devices
* @head: list of devices
*
* Note: As most callers use a stack allocated list_head,
* we force a list_del() to make sure stack wont be corrupted later.
*/
void unregister_netdevice_many(struct list_head *head)
{
@ -5836,6 +5839,7 @@ void unregister_netdevice_many(struct list_head *head)
rollback_registered_many(head);
list_for_each_entry(dev, head, unreg_list)
net_set_todo(dev);
list_del(head);
}
}
EXPORT_SYMBOL(unregister_netdevice_many);
@ -6252,7 +6256,6 @@ static void __net_exit default_device_exit_batch(struct list_head *net_list)
}
}
unregister_netdevice_many(&dev_kill_list);
list_del(&dev_kill_list);
rtnl_unlock();
}

View File

@ -1601,7 +1601,6 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh)
ops->dellink(dev, &list_kill);
unregister_netdevice_many(&list_kill);
list_del(&list_kill);
return 0;
}

View File

@ -1746,7 +1746,6 @@ void ieee80211_remove_interfaces(struct ieee80211_local *local)
}
mutex_unlock(&local->iflist_mtx);
unregister_netdevice_many(&unreg_list);
list_del(&unreg_list);
list_for_each_entry_safe(sdata, tmp, &wdev_list, list) {
list_del(&sdata->list);