From: Sven Eckelmann Date: Thu, 29 Sep 2016 15:22:58 +0000 (+0200) Subject: batman-adv: Modify neigh_list only with rcu-list functions X-Git-Tag: v4.8.9~14 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6de98e87effb2078f2bd5bc5b354dc50808b85b5;p=thirdparty%2Fkernel%2Fstable.git batman-adv: Modify neigh_list only with rcu-list functions commit 9ca488dd53088d4fcc97258aeeccf21f63b7da1e upstream. 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 Acked-by: Linus Lüssing Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 3940b5d244214..3e9667e467c3f 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);