[PATCH 4.18 15/53] batman-adv: fix hardif_neigh refcount on queue_work() failure

Greg Kroah-Hartman
2018-10-19T01:58:21Z

From: Marek Lindner <mareklindner@neomailbox.ch>

[ Upstream commit 4c4af6900844ab04c9434c972021d7b48610e06a ]

The hardif_neigh refcounter is to be decreased by the queued work and
currently is never decreased if the queue_work() call fails.
Fix by checking the queue_work() return value and decrease refcount
if necessary.

Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/batman-adv/bat_v_elp.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/net/batman-adv/bat_v_elp.c
+++ b/net/batman-adv/bat_v_elp.c
@@ -268,6 +268,7 @@ static void batadv_v_elp_periodic_work(s
struct batadv_priv *bat_priv;
struct sk_buff *skb;
u32 elp_interval;
+ bool ret;

bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work);
hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v);
@@ -329,8 +330,11 @@ static void batadv_v_elp_periodic_work(s
* may sleep and that is not allowed in an rcu protected
* context. Therefore schedule a task for that.
*/
- queue_work(batadv_event_workqueue,
- &hardif_neigh->bat_v.metric_work);
+ ret = queue_work(batadv_event_workqueue,
+ &hardif_neigh->bat_v.metric_work);
+
+ if (!ret)
+ batadv_hardif_neigh_put(hardif_neigh);
}
rcu_read_unlock();