[B.A.T.M.A.N.] [PATCH 7/7] batman-adv: Increase orig_node refcount before releasing rcu read lock

Linus Lüssing
2011-02-04T15:21:36Z

When unicast_send_skb() is increasing the orig_node's refcount another
thread might have been freeing this orig_node already. We need to
increase the refcount in the rcu read lock protected area to avoid that.

Signed-off-by: Linus Lüssing <linus.luessing@ascom.ch>
---
gateway_client.c | 3 +++
unicast.c | 1 -
2 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/batman-adv/gateway_client.c b/batman-adv/gateway_client.c
index 4624515..b3cda22 100644
--- a/batman-adv/gateway_client.c
+++ b/batman-adv/gateway_client.c
@@ -55,6 +55,9 @@ void *gw_get_selected(struct bat_priv *bat_priv)
}

orig_node = curr_gateway_tmp->orig_node;
+ if (orig_node)
+ kref_get(&orig_node->refcount);
+
rcu_read_unlock();

return orig_node;
diff --git a/batman-adv/unicast.c b/batman-adv/unicast.c
index 580b547..f4f5115 100644
--- a/batman-adv/unicast.c
+++ b/batman-adv/unicast.c
@@ -298,7 +298,6 @@ int unicast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv)
if (!orig_node)
goto trans_search;

- kref_get(&orig_node->refcount);
goto find_router;
} else {
rcu_read_lock();
--
1.7.2.3