Commit 87757a91 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: force a list_del() in unregister_netdevice_many() 



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

See commit f87e6f47 ("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: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ba6de0f5

drivers/net/macvlan.c

+0 −1
Original line number Diff line number Diff line
@@ -1036,7 +1036,6 @@ 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. */

net/core/dev.c

+4 −1
Original line number Diff line number Diff line
@@ -6613,6 +6613,9 @@ 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)

{
@@ -6622,6 +6625,7 @@ 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);
@@ -7077,7 +7081,6 @@ 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();

}

net/core/rtnetlink.c

+0 −1
Original line number Diff line number Diff line
@@ -1744,7 +1744,6 @@ 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;

}

net/mac80211/iface.c

+0 −1
Original line number Diff line number Diff line
@@ -1758,7 +1758,6 @@ 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);

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