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: fed2826b490c ("batman-adv: add list of unique single hop neighbors per hard-interface") Signed-off-by: Sven Eckelmann sven.eckelmann@open-mesh.com --- net/batman-adv/originator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 3940b5d..3e9667e 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -537,7 +537,7 @@ 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);