The following commit has been merged in the merge/master branch: commit 88a7a4ed0b5898315c255ee0cc271686ae2c0ec2 Author: Sven Eckelmann sven@narfation.org Date: Tue Jan 5 12:06:25 2016 +0100

batman-adv: Drop immediate batadv_hard_iface free function

It is not allowed to free the memory of an object which is part of a list which is protected by rcu-read-side-critical sections without making sure that no other context is accessing the object anymore. This usually happens by removing the references to this object and then waiting until the rcu grace period is over and no one (allowedly) accesses it anymore.

But the _now functions ignore this completely. They free the object directly even when a different context still tries to access it. This has to be avoided and thus these functions must be removed and all functions have to use batadv_hardif_free_ref.

Fixes: 9bb33b8d88e3 ("batman-adv: split tq information in neigh_node struct") Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Marek Lindner mareklindner@neomailbox.ch

diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h index 5a31420..7b12ea8 100644 --- a/net/batman-adv/hard-interface.h +++ b/net/batman-adv/hard-interface.h @@ -75,18 +75,6 @@ batadv_hardif_free_ref(struct batadv_hard_iface *hard_iface) call_rcu(&hard_iface->rcu, batadv_hardif_free_rcu); }

-/** - * batadv_hardif_free_ref_now - decrement the hard interface refcounter and - * possibly free it (without rcu callback) - * @hard_iface: the hard interface to free - */ -static inline void -batadv_hardif_free_ref_now(struct batadv_hard_iface *hard_iface) -{ - if (atomic_dec_and_test(&hard_iface->refcount)) - batadv_hardif_free_rcu(&hard_iface->rcu); -} - static inline struct batadv_hard_iface * batadv_primary_if_get_selected(struct batadv_priv *bat_priv) { diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 229651f..f6ca4e5 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -221,18 +221,17 @@ void batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh) }

/** - * batadv_neigh_node_free_rcu - free the neigh_node - * @rcu: rcu pointer of the neigh_node + * batadv_neigh_node_release - release neigh_node from lists and queue for + * free after rcu grace period + * @neigh_node: neigh neighbor to free */ -static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) +static void batadv_neigh_node_release(struct batadv_neigh_node *neigh_node) { struct hlist_node *node_tmp; - struct batadv_neigh_node *neigh_node; struct batadv_hardif_neigh_node *hardif_neigh; struct batadv_neigh_ifinfo *neigh_ifinfo; struct batadv_algo_ops *bao;

- neigh_node = container_of(rcu, struct batadv_neigh_node, rcu); bao = neigh_node->orig_node->bat_priv->bat_algo_ops;

hlist_for_each_entry_safe(neigh_ifinfo, node_tmp, @@ -251,9 +250,9 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) if (bao->bat_neigh_free) bao->bat_neigh_free(neigh_node);

- batadv_hardif_free_ref_now(neigh_node->if_incoming); + batadv_hardif_free_ref(neigh_node->if_incoming);

- kfree(neigh_node); + kfree_rcu(neigh_node, rcu); }

/** @@ -264,7 +263,7 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node) { if (atomic_dec_and_test(&neigh_node->refcount)) - call_rcu(&neigh_node->rcu, batadv_neigh_node_free_rcu); + batadv_neigh_node_release(neigh_node); }

/**