batman-adv: mcast: fix memory leak on deleting a batman-adv interface

The batman-adv multicast tracker TVLV handler is registered for the
new batman-adv multicast packet type upon creating a batman-adv interface,
but not unregistered again upon the interface's deletion, leading to a
memory leak.

Fix this memory leak by calling the according TVLV handler unregister
routine for the multicast tracker TVLV upon batman-adv interface
deletion.

Fixes: 07afe1ba288c ("batman-adv: mcast: implement multicast packet reception and forwarding")
Reported-and-tested-by: syzbot+ebe64cc5950868e77358@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000beadc4060f0cbc23@google.com/
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index b4f8b4af1722620f459491cd2bdcad9d6dfa7e11..14088c4ff2f66f9049858598f30dc0069c27fb70 100644 (file)
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -2175,6 +2175,7 @@ void batadv_mcast_free(struct batadv_priv *bat_priv)
        cancel_delayed_work_sync(&bat_priv->mcast.work);
 
        batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
+       batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST_TRACKER, 1);
        batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 2);
 
        /* safely calling outside of worker, as worker was canceled above */