diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index b6466e71f5e1..d21e7ebd91ca 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -480,18 +480,16 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m if (connected) rt = (struct rtable *) __sk_dst_check(sk, 0); + rcu_read_lock(); if (rt == NULL) { - struct ip_options_rcu *inet_opt; + const struct ip_options_rcu *inet_opt; - rcu_read_lock(); inet_opt = rcu_dereference(inet->inet_opt); /* Use correct destination address if we have options. */ if (inet_opt && inet_opt->opt.srr) daddr = inet_opt->opt.faddr; - rcu_read_unlock(); - /* If this fails, retransmit mechanism of transport layer will * keep trying until route appears or the connection times * itself out. @@ -503,12 +501,20 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m sk->sk_bound_dev_if); if (IS_ERR(rt)) goto no_route; - sk_setup_caps(sk, &rt->dst); + if (connected) + sk_setup_caps(sk, &rt->dst); + else + dst_release(&rt->dst); /* safe since we hold rcu_read_lock */ } - skb_dst_set(skb, dst_clone(&rt->dst)); + + /* We dont need to clone dst here, it is guaranteed to not disappear. + * __dev_xmit_skb() might force a refcount if needed. + */ + skb_dst_set_noref(skb, &rt->dst); /* Queue the packet to IP for output */ rc = ip_queue_xmit(skb, &inet->cork.fl); + rcu_read_unlock(); error: /* Update stats */ @@ -525,6 +531,7 @@ out: return rc; no_route: + rcu_read_unlock(); IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); kfree_skb(skb); rc = -EHOSTUNREACH;