l2tp: prevent lockdep issue in l2tp_tunnel_register()

[platform/kernel/linux-rpi.git] / net / l2tp / l2tp_core.c

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 68d8b2a..a2b13e2 100644 (file)
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -1041,7 +1041,7 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, uns
        IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED);
        nf_reset_ct(skb);
 
-       bh_lock_sock(sk);
+       bh_lock_sock_nested(sk);
        if (sock_owned_by_user(sk)) {
                kfree_skb(skb);
                ret = NET_XMIT_DROP;
@@ -1387,8 +1387,6 @@ out:
        return err;
 }
 
-static struct lock_class_key l2tp_socket_class;
-
 int l2tp_tunnel_create(int fd, int version, u32 tunnel_id, u32 peer_tunnel_id,
                       struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp)
 {
@@ -1484,6 +1482,7 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
        }
 
        sk = sock->sk;
+       lock_sock(sk);
        write_lock_bh(&sk->sk_callback_lock);
        ret = l2tp_validate_socket(sk, net, tunnel->encap);
        if (ret < 0)
@@ -1491,14 +1490,6 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
        rcu_assign_sk_user_data(sk, tunnel);
        write_unlock_bh(&sk->sk_callback_lock);
 
-       sock_hold(sk);
-       tunnel->sock = sk;
-       tunnel->l2tp_net = net;
-
-       spin_lock_bh(&pn->l2tp_tunnel_idr_lock);
-       idr_replace(&pn->l2tp_tunnel_idr, tunnel, tunnel->tunnel_id);
-       spin_unlock_bh(&pn->l2tp_tunnel_idr_lock);
-
        if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
                struct udp_tunnel_sock_cfg udp_cfg = {
                        .sk_user_data = tunnel,
@@ -1512,9 +1503,16 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
 
        tunnel->old_sk_destruct = sk->sk_destruct;
        sk->sk_destruct = &l2tp_tunnel_destruct;
-       lockdep_set_class_and_name(&sk->sk_lock.slock, &l2tp_socket_class,
-                                  "l2tp_sock");
        sk->sk_allocation = GFP_ATOMIC;
+       release_sock(sk);
+
+       sock_hold(sk);
+       tunnel->sock = sk;
+       tunnel->l2tp_net = net;
+
+       spin_lock_bh(&pn->l2tp_tunnel_idr_lock);
+       idr_replace(&pn->l2tp_tunnel_idr, tunnel, tunnel->tunnel_id);
+       spin_unlock_bh(&pn->l2tp_tunnel_idr_lock);
 
        trace_register_tunnel(tunnel);
 
@@ -1525,6 +1523,7 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
 
 err_inval_sock:
        write_unlock_bh(&sk->sk_callback_lock);
+       release_sock(sk);
 
        if (tunnel->fd < 0)
                sock_release(sock);