Repository : ssh://git@open-mesh.org/batman-adv
On branch : maint
commit ead9389a3a0af4de210c977a0b11d57180d7c941 Author: Sven Eckelmann sven@narfation.org Date: Sun Jan 31 13:28:00 2016 +0100
batman-adv: Only put orig_node_vlan list reference when removed
The batadv_orig_node_vlan reference counter in batadv_tt_global_size_mod can only be reduced when the list entry was actually removed. Otherwise the reference counter may reach zero when batadv_tt_global_size_mod is called from two different contexts for the same orig_node_vlan but only one context is actually removing the entry from the list.
The release function for this orig_node_vlan is not called inside the vlan_list_lock spinlock protected region because the function batadv_tt_global_size_mod still holds a orig_node_vlan reference for the object pointer on the stack. Thus the actual release function (when required) will be called only at the end of the function.
Fixes: 21a57f6e7a3b ("batman-adv: make the TT CRC logic VLAN specific") Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Marek Lindner mareklindner@neomailbox.ch
ead9389a3a0af4de210c977a0b11d57180d7c941 net/batman-adv/translation-table.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 9fcf6bf..7301a92 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -311,9 +311,11 @@ 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_init_rcu(&vlan->list); + if (!hlist_unhashed(&vlan->list)) { + hlist_del_init_rcu(&vlan->list); + batadv_orig_node_vlan_free_ref(vlan); + } spin_unlock_bh(&orig_node->vlan_list_lock); - batadv_orig_node_vlan_free_ref(vlan); }
batadv_orig_node_vlan_free_ref(vlan);