3.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Antonio Quartulli <anto...@open-mesh.com>

[ Upstream commit 377fe0f968b30a1a714fab53a908061914f30e26 ]

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 <anto...@open-mesh.com>
Signed-off-by: Marek Lindner <mareklind...@neomailbox.ch>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 net/batman-adv/gateway_client.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

--- 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 *
@@ -408,9 +410,14 @@ static void batadv_gw_node_add(struct ba
        if (gateway->bandwidth_down == 0)
                return;
 
+       if (!atomic_inc_not_zero(&orig_node->refcount))
+               return;
+
        gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
-       if (!gw_node)
+       if (!gw_node) {
+               batadv_orig_node_free_ref(orig_node);
                return;
+       }
 
        INIT_HLIST_NODE(&gw_node->list);
        gw_node->orig_node = orig_node;


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