The following commit has been merged in the master branch: commit 9ca488dd53088d4fcc97258aeeccf21f63b7da1e Author: Sven Eckelmann sven.eckelmann@open-mesh.com Date: Thu Sep 29 17:22:58 2016 +0200

batman-adv: Modify neigh_list only with rcu-list functions

The batadv_hard_iface::neigh_list is accessed via rcu based primitives. Thus all operations done on it have to fulfill the requirements by RCU. So using non-RCU mechanisms like hlist_add_head is not allowed because it misses the barriers required to protect concurrent readers when accessing the data behind the pointer.

Fixes: cef63419f7db ("batman-adv: add list of unique single hop neighbors per hard-interface") Signed-off-by: Sven Eckelmann sven.eckelmann@open-mesh.com Acked-by: Linus Lüssing linus.luessing@c0d3.blue Signed-off-by: Simon Wunderlich sw@simonwunderlich.de

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 5f3bfc4..7c8d160 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -544,7 +544,7 @@ batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface, if (bat_priv->algo_ops->neigh.hardif_init) bat_priv->algo_ops->neigh.hardif_init(hardif_neigh);

- hlist_add_head(&hardif_neigh->list, &hard_iface->neigh_list); + hlist_add_head_rcu(&hardif_neigh->list, &hard_iface->neigh_list);

out: spin_unlock_bh(&hard_iface->neigh_list_lock);