diff options
Diffstat (limited to 'drivers/net/ovpn/tcp.c')
| -rw-r--r-- | drivers/net/ovpn/tcp.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/net/ovpn/tcp.c b/drivers/net/ovpn/tcp.c index 0d7f30360d87..ec2bbc28c196 100644 --- a/drivers/net/ovpn/tcp.c +++ b/drivers/net/ovpn/tcp.c @@ -199,7 +199,19 @@ void ovpn_tcp_socket_detach(struct ovpn_socket *ovpn_sock) sk->sk_data_ready = peer->tcp.sk_cb.sk_data_ready; sk->sk_write_space = peer->tcp.sk_cb.sk_write_space; sk->sk_prot = peer->tcp.sk_cb.prot; - sk->sk_socket->ops = peer->tcp.sk_cb.ops; + + /* tcp_close() may race this function and could set + * sk->sk_socket to NULL. It does so by invoking + * sock_orphan(), which holds sk_callback_lock before + * doing the assignment. + * + * For this reason we acquire the same lock to avoid + * sk_socket to disappear under our feet + */ + write_lock_bh(&sk->sk_callback_lock); + if (sk->sk_socket) + sk->sk_socket->ops = peer->tcp.sk_cb.ops; + write_unlock_bh(&sk->sk_callback_lock); rcu_assign_sk_user_data(sk, NULL); } @@ -487,6 +499,7 @@ int ovpn_tcp_socket_attach(struct ovpn_socket *ovpn_sock, /* make sure no pre-existing encapsulation handler exists */ if (ovpn_sock->sk->sk_user_data) return -EBUSY; + rcu_assign_sk_user_data(ovpn_sock->sk, ovpn_sock); /* only a fully connected socket is expected. Connection should be * handled in userspace @@ -495,13 +508,14 @@ int ovpn_tcp_socket_attach(struct ovpn_socket *ovpn_sock, net_err_ratelimited("%s: provided TCP socket is not in ESTABLISHED state: %d\n", netdev_name(peer->ovpn->dev), ovpn_sock->sk->sk_state); - return -EINVAL; + ret = -EINVAL; + goto err; } ret = strp_init(&peer->tcp.strp, ovpn_sock->sk, &cb); if (ret < 0) { DEBUG_NET_WARN_ON_ONCE(1); - return ret; + goto err; } INIT_WORK(&peer->tcp.defer_del_work, ovpn_tcp_peer_del_work); @@ -536,6 +550,9 @@ int ovpn_tcp_socket_attach(struct ovpn_socket *ovpn_sock, strp_check_rcv(&peer->tcp.strp); return 0; +err: + rcu_assign_sk_user_data(ovpn_sock->sk, NULL); + return ret; } static void ovpn_tcp_close(struct sock *sk, long timeout) |