batman-adv: prevent potential hlist double deletion

The hlist_del_rcu() call in batadv_tt_global_size_mod() does not check
if the element still is part of the list prior to deletion. The atomic
list counter should prevent the worst but converting to
hlist_del_init_rcu() ensures the element can't be deleted more than
once.

Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 9e1f866..596e326 100644 (file)
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -315,7 +315,7 @@ static void batadv_tt_global_size_mod(struct batadv_orig_node *orig_node,
 
        if (atomic_add_return(v, &vlan->tt.num_entries) == 0) {
                spin_lock_bh(&orig_node->vlan_list_lock);
-               hlist_del_rcu(&vlan->list);
+               hlist_del_init_rcu(&vlan->list);
                spin_unlock_bh(&orig_node->vlan_list_lock);
                batadv_orig_node_vlan_free_ref(vlan);
        }