[PATCH 3.2 027/140] batman-adv: Fix lock for ogm cnt access in batadv_iv_ogm_calc_tq

Ben Hutchings
2018-02-28T17:00:39Z

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>
[bwh: Backported to 3.2:
- s/bat_iv\.ogm_cnt_lock/ogm_cnt_lock/
- Adjust context]
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
@@ -760,10 +760,10 @@ static int bat_ogm_calc_tq(struct orig_n
orig_node->last_valid = jiffies;

/* find packet count of corresponding one hop neighbor */
- spin_lock_bh(&orig_node->ogm_cnt_lock);
+ spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num];
neigh_rq_count = neigh_node->real_packet_count;
- spin_unlock_bh(&orig_node->ogm_cnt_lock);
+ spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);

/* pay attention to not get a value bigger than 100 % */
total_count = (orig_eq_count > neigh_rq_count ?