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>
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index c835e13..90cff58 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -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 @@
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);