Commit 9ca488dd authored Sep 29, 2016 by Sven Eckelmann Committed by Simon Wunderlich Oct 17, 2016

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: cef63419 ("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>

parent 29fbff86

net/batman-adv/originator.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);

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