batman-adv: increase orig refcount when storing ref in gw_node

A pointer to the orig_node representing a bat-gateway is
stored in the gw_node->orig_node member, but the refcount
for such orig_node is never increased.
This leads to memory faults when gw_node->orig_node is accessed
and the originator has already been freed.

Fix this by increasing the refcount on gw_node creation
and decreasing it on gw_node free.

Signed-off-by: Antonio Quartulli <antonio@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
This commit is contained in:
Antonio Quartulli 2014-05-02 01:35:13 +02:00 committed by Antonio Quartulli
parent be181015a1
commit 377fe0f968

View File

@ -42,8 +42,10 @@
static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
{
if (atomic_dec_and_test(&gw_node->refcount))
if (atomic_dec_and_test(&gw_node->refcount)) {
batadv_orig_node_free_ref(gw_node->orig_node);
kfree_rcu(gw_node, rcu);
}
}
static struct batadv_gw_node *
@ -406,10 +408,15 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
if (gateway->bandwidth_down == 0)
return;
gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
if (!gw_node)
if (!atomic_inc_not_zero(&orig_node->refcount))
return;
gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
if (!gw_node) {
batadv_orig_node_free_ref(orig_node);
return;
}
INIT_HLIST_NODE(&gw_node->list);
gw_node->orig_node = orig_node;
atomic_set(&gw_node->refcount, 1);