3.16.39-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Sabrina Dubroca <[email protected]> commit 2f86953e7436c9b9a4690909c5e2db24799e173b upstream. Tunnel deletion is delayed by both a workqueue (l2tp_tunnel_delete -> wq -> l2tp_tunnel_del_work) and RCU (sk_destruct -> RCU -> l2tp_tunnel_destruct). By the time l2tp_tunnel_destruct() runs to destroy the tunnel and finish destroying the socket, the private data reserved via the net_generic mechanism has already been freed, but l2tp_tunnel_destruct() actually uses this data. Make sure tunnel deletion for the netns has completed before returning from l2tp_exit_net() by first flushing the tunnel removal workqueue, and then waiting for RCU callbacks to complete. Fixes: 167eb17e0b17 ("l2tp: create tunnel sockets in the right namespace") Signed-off-by: Sabrina Dubroca <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- net/l2tp/l2tp_core.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1892,6 +1892,9 @@ static __net_exit void l2tp_exit_net(str (void)l2tp_tunnel_delete(tunnel); } rcu_read_unlock_bh(); + + flush_workqueue(l2tp_wq); + rcu_barrier(); } static struct pernet_operations l2tp_net_ops = {
