The following commit has been merged in the maint branch: commit 05bfe357936a59fd23752599586ea76c3e79e920 Author: Marek Lindner lindner_marek@yahoo.de Date: Wed Jan 19 20:01:39 2011 +0000

batman-adv: protect neigh_nodes used outside of rcu_locks with refcounting

Signed-off-by: Marek Lindner lindner_marek@yahoo.de

diff --git a/routing.c b/routing.c index 97f3216..c15e6c1 100644 --- a/routing.c +++ b/routing.c @@ -151,6 +151,7 @@ static int is_bidirectional_neigh(struct orig_node *orig_node, struct neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL; struct hlist_node *node; unsigned char total_count; + int ret = 0;

if (orig_node == orig_neigh_node) { rcu_read_lock(); @@ -162,7 +163,6 @@ static int is_bidirectional_neigh(struct orig_node *orig_node, (tmp_neigh_node->if_incoming == if_incoming)) neigh_node = tmp_neigh_node; } - rcu_read_unlock();

if (!neigh_node) neigh_node = create_neighbor(orig_node, @@ -171,7 +171,10 @@ static int is_bidirectional_neigh(struct orig_node *orig_node, if_incoming); /* create_neighbor failed, return 0 */ if (!neigh_node) - return 0; + goto unlock; + + kref_get(&neigh_node->refcount); + rcu_read_unlock();

neigh_node->last_valid = jiffies; } else { @@ -185,7 +188,6 @@ static int is_bidirectional_neigh(struct orig_node *orig_node, (tmp_neigh_node->if_incoming == if_incoming)) neigh_node = tmp_neigh_node; } - rcu_read_unlock();

if (!neigh_node) neigh_node = create_neighbor(orig_neigh_node, @@ -194,7 +196,10 @@ static int is_bidirectional_neigh(struct orig_node *orig_node, if_incoming); /* create_neighbor failed, return 0 */ if (!neigh_node) - return 0; + goto unlock; + + kref_get(&neigh_node->refcount); + rcu_read_unlock(); }

orig_node->last_valid = jiffies; @@ -250,9 +255,16 @@ static int is_bidirectional_neigh(struct orig_node *orig_node, /* if link has the minimum required transmission quality * consider it bidirectional */ if (batman_packet->tq >= TQ_TOTAL_BIDRECT_LIMIT) - return 1; + ret = 1;

- return 0; + goto out; + +unlock: + rcu_read_unlock(); +out: + if (neigh_node) + kref_put(&neigh_node->refcount, neigh_node_free_ref); + return ret; }

static void update_orig(struct bat_priv *bat_priv, @@ -287,23 +299,25 @@ static void update_orig(struct bat_priv *bat_priv, tmp_neigh_node->tq_avg = ring_buffer_avg(tmp_neigh_node->tq_recv); } - rcu_read_unlock();

if (!neigh_node) { struct orig_node *orig_tmp;

orig_tmp = get_orig_node(bat_priv, ethhdr->h_source); if (!orig_tmp) - return; + goto unlock;

neigh_node = create_neighbor(orig_node, orig_tmp, ethhdr->h_source, if_incoming); if (!neigh_node) - return; + goto unlock; } else bat_dbg(DBG_BATMAN, bat_priv, "Updating existing last-hop neighbor of originator\n");

+ kref_get(&neigh_node->refcount); + rcu_read_unlock(); + orig_node->flags = batman_packet->flags; neigh_node->last_valid = jiffies;

@@ -357,6 +371,14 @@ update_gw: (atomic_read(&bat_priv->gw_mode) == GW_MODE_CLIENT) && (atomic_read(&bat_priv->gw_sel_class) > 2)) gw_check_election(bat_priv, orig_node); + + goto out; + +unlock: + rcu_read_unlock(); +out: + if (neigh_node) + kref_put(&neigh_node->refcount, neigh_node_free_ref); }

/* checks whether the host restarted and is in the protection time.