[B.A.T.M.A.N.] [PATCH] batman-adv: protect bit operations to count OGMs with spinlock

[Marek Lindner]

Reported-by: Linus Lüssing <linus.luess...@saxnet.de>
Signed-off-by: Marek Lindner <lindner_ma...@yahoo.de>
---
 batman-adv/routing.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/batman-adv/routing.c b/batman-adv/routing.c
index a90d105..fe3471a 100644
--- a/batman-adv/routing.c
+++ b/batman-adv/routing.c
@@ -539,18 +539,19 @@ static char count_real_packets(struct ethhdr *ethhdr,
        char is_duplicate = 0;
        int32_t seq_diff;
        int need_update = 0;
-       int set_mark;
+       int set_mark, ret = -1;
 
        orig_node = get_orig_node(bat_priv, batman_packet->orig);
        if (!orig_node)
                return 0;
 
+       spin_lock_bh(&orig_node->ogm_cnt_lock);
        seq_diff = batman_packet->seqno - orig_node->last_real_seqno;
 
        /* signalize caller that the packet is to be dropped. */
        if (window_protected(bat_priv, seq_diff,
                             &orig_node->batman_seqno_reset))
-               goto err;
+               goto out;
 
        rcu_read_lock();
        hlist_for_each_entry_rcu(tmp_neigh_node, node,
@@ -583,12 +584,12 @@ static char count_real_packets(struct ethhdr *ethhdr,
                orig_node->last_real_seqno = batman_packet->seqno;
        }
 
-       kref_put(&orig_node->refcount, orig_node_free_ref);
-       return is_duplicate;
+       ret = is_duplicate;
 
-err:
+out:
+       spin_unlock_bh(&orig_node->ogm_cnt_lock);
        kref_put(&orig_node->refcount, orig_node_free_ref);
-       return -1;
+       return ret;
 }
 
 void receive_bat_packet(struct ethhdr *ethhdr,
-- 
1.7.2.3