diff --git a/include/linux/tcp.h b/include/linux/tcp.h index c2025f159641..115389e9b945 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -463,7 +463,7 @@ struct tcp_sock { const struct tcp_sock_af_ops *af_specific; /* TCP MD5 Signature Option information */ - struct tcp_md5sig_info *md5sig_info; + struct tcp_md5sig_info __rcu *md5sig_info; #endif /* When the cookie options are generated and exchanged, then this diff --git a/include/net/tcp.h b/include/net/tcp.h index 10ae4c7b6b4f..78880ba0f560 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1150,6 +1150,7 @@ struct tcp_md5sig_key { /* - sock block */ struct tcp_md5sig_info { struct hlist_head head; + struct rcu_head rcu; }; /* - pseudo header */ diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index da5d3226771b..567cca9b30df 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -879,14 +879,18 @@ struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, struct tcp_md5sig_key *key; struct hlist_node *pos; unsigned int size = sizeof(struct in_addr); + struct tcp_md5sig_info *md5sig; - if (!tp->md5sig_info) + /* caller either holds rcu_read_lock() or socket lock */ + md5sig = rcu_dereference_check(tp->md5sig_info, + sock_owned_by_user(sk)); + if (!md5sig) return NULL; #if IS_ENABLED(CONFIG_IPV6) if (family == AF_INET6) size = sizeof(struct in6_addr); #endif - hlist_for_each_entry_rcu(key, pos, &tp->md5sig_info->head, node) { + hlist_for_each_entry_rcu(key, pos, &md5sig->head, node) { if (key->family != family) continue; if (!memcmp(&key->addr, addr, size)) @@ -932,7 +936,8 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, return 0; } - md5sig = tp->md5sig_info; + md5sig = rcu_dereference_protected(tp->md5sig_info, + sock_owned_by_user(sk)); if (!md5sig) { md5sig = kmalloc(sizeof(*md5sig), gfp); if (!md5sig) @@ -940,7 +945,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, sk_nocaps_add(sk, NETIF_F_GSO_MASK); INIT_HLIST_HEAD(&md5sig->head); - tp->md5sig_info = md5sig; + rcu_assign_pointer(tp->md5sig_info, md5sig); } key = sock_kmalloc(sk, sizeof(*key), gfp); @@ -966,6 +971,7 @@ int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family) { struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *key; + struct tcp_md5sig_info *md5sig; key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&addr, AF_INET); if (!key) @@ -973,7 +979,9 @@ int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family) hlist_del_rcu(&key->node); atomic_sub(sizeof(*key), &sk->sk_omem_alloc); kfree_rcu(key, rcu); - if (hlist_empty(&tp->md5sig_info->head)) + md5sig = rcu_dereference_protected(tp->md5sig_info, + sock_owned_by_user(sk)); + if (hlist_empty(&md5sig->head)) tcp_free_md5sig_pool(); return 0; } @@ -984,10 +992,13 @@ void tcp_clear_md5_list(struct sock *sk) struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *key; struct hlist_node *pos, *n; + struct tcp_md5sig_info *md5sig; - if (!hlist_empty(&tp->md5sig_info->head)) + md5sig = rcu_dereference_protected(tp->md5sig_info, 1); + + if (!hlist_empty(&md5sig->head)) tcp_free_md5sig_pool(); - hlist_for_each_entry_safe(key, pos, n, &tp->md5sig_info->head, node) { + hlist_for_each_entry_safe(key, pos, n, &md5sig->head, node) { hlist_del_rcu(&key->node); atomic_sub(sizeof(*key), &sk->sk_omem_alloc); kfree_rcu(key, rcu); @@ -1009,12 +1020,9 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, char __user *optval, if (sin->sin_family != AF_INET) return -EINVAL; - if (!cmd.tcpm_key || !cmd.tcpm_keylen) { - if (!tcp_sk(sk)->md5sig_info) - return -ENOENT; + if (!cmd.tcpm_key || !cmd.tcpm_keylen) return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, AF_INET); - } if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) return -EINVAL; @@ -1896,7 +1904,7 @@ void tcp_v4_destroy_sock(struct sock *sk) /* Clean up the MD5 key list, if any */ if (tp->md5sig_info) { tcp_clear_md5_list(sk); - kfree(tp->md5sig_info); + kfree_rcu(tp->md5sig_info, rcu); tp->md5sig_info = NULL; } #endif diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index bec41f9a6413..c25018106ef2 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -571,8 +571,6 @@ static int tcp_v6_parse_md5_keys (struct sock *sk, char __user *optval, return -EINVAL; if (!cmd.tcpm_keylen) { - if (!tcp_sk(sk)->md5sig_info) - return -ENOENT; if (ipv6_addr_v4mapped(&sin6->sin6_addr)) return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], AF_INET);