From 0c501345ce24983d234fc913e7e81b6abe59cb54 Mon Sep 17 00:00:00 2001 From: Antonio Quartulli Date: Fri, 19 Apr 2013 11:04:52 +0200 Subject: [PATCH] batman-adv: fix global protection fault during soft_iface destruction batadv_mesh_free() schedules some RCU callbacks which need the bat_priv struct to do their jobs, while free_netdev(), which is called immediately after, is destroying the private data. Put an rcu_barrier() in the middle so that free_netdev() is invoked only after all the callbacks returned. This bug has been introduced by ab8f433dd39be94e8617cff2dfe9f7eca162eb15 ("batman-adv: Move deinitialization of soft-interface to destructor") Signed-off-by: Antonio Quartulli Signed-off-by: Marek Lindner Signed-off-by: David S. Miller --- net/batman-adv/soft-interface.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 403b8c46085e..6f20d339e33a 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -582,6 +582,13 @@ static void batadv_softif_free(struct net_device *dev) { batadv_debugfs_del_meshif(dev); batadv_mesh_free(dev); + + /* some scheduled RCU callbacks need the bat_priv struct to accomplish + * their tasks. Wait for them all to be finished before freeing the + * netdev and its private data (bat_priv) + */ + rcu_barrier(); + free_netdev(dev); }