[PATCH 3.16.y-ckt 098/133] batman-adv: fix multicast counter when purging originators

[Luis Henriques]

3.16.7-ckt18 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@xxxxxxxxx>

commit a5164886b0bdadd662f9715a7541432c4d1a0d99 upstream.

When purging an orig_node we should only decrease counter tracking the
number of nodes without multicast optimizations support if it was
increased through this orig_node before.

A not yet quite initialized orig_node (meaning it did not have its turn
in the mcast-tvlv handler so far) which gets purged would not adhere to
this and will lead to a counter imbalance.

Fixing this by adding a check whether the orig_node is mcast-initalized
before decreasing the counter in the mcast-orig_node-purging routine.

Introduced by 60432d756cf06e597ef9da511402dd059b112447
("batman-adv: Announce new capability via multicast TVLV")

Reported-by: Tobias Hachmer <tobias@xxxxxxxxxx>
Signed-off-by: Linus LÃssing <linus.luessing@xxxxxxxxx>
Signed-off-by: Marek Lindner <mareklindner@xxxxxxxxxxxxx>
Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 net/batman-adv/multicast.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index 96b66fd30f96..a5e457ec4916 100644
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -739,7 +739,8 @@ void batadv_mcast_purge_orig(struct batadv_orig_node *orig)
 {
 	struct batadv_priv *bat_priv = orig->bat_priv;
 
-	if (!(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST))
+	if (!(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST) &&
+	    orig->capa_initialized & BATADV_ORIG_CAPA_HAS_MCAST)
 		atomic_dec(&bat_priv->mcast.num_disabled);
 
 	batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS);
--
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