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 <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Antonio Quartulli 2013-04-19 11:04:52 +02:00 committed by David S. Miller
parent 6e0895c2ea
commit 0c501345ce
1 changed files with 7 additions and 0 deletions

View File

@ -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);
}