[v2,maint] batman-adv: increase orig refcount when storing ref in gw_node
Commit Message
From: Antonio Quartulli <antonio@open-mesh.com>
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>
---
Change since v1:
- properly release orig_node in case of gw_node allocation failure
gateway_client.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
Comments
On Friday 02 May 2014 01:35:13 Antonio Quartulli wrote:
> From: Antonio Quartulli <antonio@open-mesh.com>
>
> 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>
> ---
>
> Change since v1:
> - properly release orig_node in case of gw_node allocation failure
>
> gateway_client.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
Applied in revision 8dbdee5.
Thanks,
Marek
@@ -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 *
@@ -406,9 +408,14 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
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;