[PATCH 3.16 052/254] batman-adv: Fix lock for ogm cnt access in batadv_iv_ogm_calc_tq

Ben Hutchings
2018-02-28T16:34:10Z

From: Sven Eckelmann <sven@narfation.org>

commit 5ba7dcfe77037b67016263ea597a8b431692ecab upstream.

The originator node object orig_neigh_node is used to when accessing the
bcast_own(_sum) and real_packet_count information. The access to them has
to be protected with the spinlock in orig_neigh_node.

But the function uses the lock in orig_node instead. This is incorrect
because they could be two different originator node objects.

Fixes: 0ede9f41b217 ("batman-adv: protect bit operations to count OGMs with spinlock")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
net/batman-adv/bat_iv_ogm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1174,7 +1174,7 @@ static int batadv_iv_ogm_calc_tq(struct
orig_node->last_seen = jiffies;

/* find packet count of corresponding one hop neighbor */
- spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);
+ spin_lock_bh(&orig_neigh_node->bat_iv.ogm_cnt_lock);
if_num = if_incoming->if_num;
orig_eq_count = orig_neigh_node->bat_iv.bcast_own_sum[if_num];
neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
@@ -1184,7 +1184,7 @@ static int batadv_iv_ogm_calc_tq(struct
} else {
neigh_rq_count = 0;
}
- spin_unlock_bh(&orig_node->bat_iv.ogm_cnt_lock);
+ spin_unlock_bh(&orig_neigh_node->bat_iv.ogm_cnt_lock);

/* pay attention to not get a value bigger than 100 % */
if (orig_eq_count > neigh_rq_count)