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authorSven Eckelmann <sven@narfation.org>2016-01-05 12:06:17 +0100
committerAntonio Quartulli <a@unstable.cc>2016-01-13 19:28:27 +0800
commitbab7c6c3deac70966a3000402c0ea6d0c20edd15 (patch)
treed6d644c3db05abb5451cd6811f53acd594e9c6be /net
parentaf63cf51b7f960aa73b32bac683cd4078f08fa0e (diff)
downloadlinux-bab7c6c3deac70966a3000402c0ea6d0c20edd15.tar.bz2
batman-adv: Fix list removal of batadv_hardif_neigh_node
The neigh_list with batadv_hardif_neigh_node objects is accessed with only rcu_read_lock in batadv_hardif_neigh_get and batadv_iv_neigh_print. Thus it is not allowed to kfree the object before the rcu grace period ends (which may still protects context accessing this object). Therefore the object has first to be removed from the neigh_list and then it has either wait with synchronize_rcu or call_rcu till the grace period ends before it can be freed. Fixes: cef63419f7db ("batman-adv: add list of unique single hop neighbors per hard-interface") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <a@unstable.cc>
Diffstat (limited to 'net')
-rw-r--r--net/batman-adv/originator.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 3c782a33bdac..ae6d18cafc5a 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -211,10 +211,6 @@ static void batadv_hardif_neigh_free_rcu(struct rcu_head *rcu)
hardif_neigh = container_of(rcu, struct batadv_hardif_neigh_node, rcu);
- spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock);
- hlist_del_init_rcu(&hardif_neigh->list);
- spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock);
-
batadv_hardif_free_ref_now(hardif_neigh->if_incoming);
kfree(hardif_neigh);
}
@@ -227,8 +223,13 @@ static void batadv_hardif_neigh_free_rcu(struct rcu_head *rcu)
static void
batadv_hardif_neigh_free_now(struct batadv_hardif_neigh_node *hardif_neigh)
{
- if (atomic_dec_and_test(&hardif_neigh->refcount))
+ if (atomic_dec_and_test(&hardif_neigh->refcount)) {
+ spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock);
+ hlist_del_init_rcu(&hardif_neigh->list);
+ spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock);
+
batadv_hardif_neigh_free_rcu(&hardif_neigh->rcu);
+ }
}
/**
@@ -238,8 +239,13 @@ batadv_hardif_neigh_free_now(struct batadv_hardif_neigh_node *hardif_neigh)
*/
void batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh)
{
- if (atomic_dec_and_test(&hardif_neigh->refcount))
+ if (atomic_dec_and_test(&hardif_neigh->refcount)) {
+ spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock);
+ hlist_del_init_rcu(&hardif_neigh->list);
+ spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock);
+
call_rcu(&hardif_neigh->rcu, batadv_hardif_neigh_free_rcu);
+ }
}
/**