tcp/dccp: fix possible race __inet_lookup_established()

[mirror_ubuntu-bionic-kernel.git] / net / ipv4 / inet_hashtables.c

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 1f26627c7fadbae49b1b3c020997253ac5a1829b..0af13f5bdc9a3ac48b42875a593c51bc7cd3d1fa 100644 (file)
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -219,9 +219,10 @@ struct sock *__inet_lookup_listener(struct net *net,
        int score, hiscore = 0, matches = 0, reuseport = 0;
        bool exact_dif = inet_exact_dif_match(net, skb);
        struct sock *sk, *result = NULL;
+       struct hlist_nulls_node *node;
        u32 phash = 0;
 
-       sk_for_each_rcu(sk, &ilb->head) {
+       sk_nulls_for_each_rcu(sk, node, &ilb->nulls_head) {
                score = compute_score(sk, net, hnum, daddr,
                                      dif, sdif, exact_dif);
                if (score > hiscore) {
@@ -442,10 +443,11 @@ static int inet_reuseport_add_sock(struct sock *sk,
                                   struct inet_listen_hashbucket *ilb)
 {
        struct inet_bind_bucket *tb = inet_csk(sk)->icsk_bind_hash;
+       const struct hlist_nulls_node *node;
        struct sock *sk2;
        kuid_t uid = sock_i_uid(sk);
 
-       sk_for_each_rcu(sk2, &ilb->head) {
+       sk_nulls_for_each_rcu(sk2, node, &ilb->nulls_head) {
                if (sk2 != sk &&
                    sk2->sk_family == sk->sk_family &&
                    ipv6_only_sock(sk2) == ipv6_only_sock(sk) &&
@@ -480,9 +482,9 @@ int __inet_hash(struct sock *sk, struct sock *osk)
        }
        if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
                sk->sk_family == AF_INET6)
-               hlist_add_tail_rcu(&sk->sk_node, &ilb->head);
+               __sk_nulls_add_node_tail_rcu(sk, &ilb->nulls_head);
        else
-               hlist_add_head_rcu(&sk->sk_node, &ilb->head);
+               __sk_nulls_add_node_rcu(sk, &ilb->nulls_head);
        sock_set_flag(sk, SOCK_RCU_FREE);
        sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 unlock:
@@ -525,10 +527,7 @@ void inet_unhash(struct sock *sk)
        spin_lock_bh(lock);
        if (rcu_access_pointer(sk->sk_reuseport_cb))
                reuseport_detach_sock(sk);
-       if (listener)
-               done = __sk_del_node_init(sk);
-       else
-               done = __sk_nulls_del_node_init_rcu(sk);
+       done = __sk_nulls_del_node_init_rcu(sk);
        if (done)
                sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
        spin_unlock_bh(lock);
@@ -664,7 +663,8 @@ void inet_hashinfo_init(struct inet_hashinfo *h)
 
        for (i = 0; i < INET_LHTABLE_SIZE; i++) {
                spin_lock_init(&h->listening_hash[i].lock);
-               INIT_HLIST_HEAD(&h->listening_hash[i].head);
+               INIT_HLIST_NULLS_HEAD(&h->listening_hash[i].nulls_head,
+                                     i + LISTENING_NULLS_BASE);
        }
 }
 EXPORT_SYMBOL_GPL(inet_hashinfo_init);