From patchwork Wed Feb 15 18:33:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Safonov X-Patchwork-Id: 13142040 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02F30C636CC for ; Wed, 15 Feb 2023 18:34:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230226AbjBOSe0 (ORCPT ); Wed, 15 Feb 2023 13:34:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230138AbjBOSd5 (ORCPT ); Wed, 15 Feb 2023 13:33:57 -0500 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [IPv6:2a00:1450:4864:20::332]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB3F639CEF for ; Wed, 15 Feb 2023 10:33:52 -0800 (PST) Received: by mail-wm1-x332.google.com with SMTP id z13so14021448wmp.2 for ; Wed, 15 Feb 2023 10:33:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=TOlhgDIYmtKFs9SA0Zk35wqmjyypaHp/x6eyU8/miKA=; b=PrBN7vDEdRdziV62LMlKC/T3An+Q9cNrhJKL8xuYIf+inYBy+KAHMbVQ6CtWaK2G8a ///LvENxrBaIOP5wu59n8fC5LzV4+YBPmv5x3XDcTkkxmQswTEZja6GkyAe0VHrOLFpV 29Jhryri+ZU9tLXQzqfj/Ic5sdXf2MBvt/A5B2wYs3HZoasLzHqqTB8fyOb+9WDapQ8o /ovRN8wKiov/OA5fB9msGrKitk99nBGVPBR2Ao1BD6Dz76+d0fyibl+OkSV4nrYs5JUe YiNcwfARGQ2F5WDxuwwxqpduQBUwWCsjxjuPWX4xX8N8Y2P6ENOOLo9l4MLkIOtdf08n 3u9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=TOlhgDIYmtKFs9SA0Zk35wqmjyypaHp/x6eyU8/miKA=; b=4Os3sZLRF6T4FjxxQBQmFMcx92HooEDool4zjOKnMGcyfngXb9QGMVU6g1OnvDlbAt MlnpvCAB5LVxuztxVjSoJTM5EkbXks0NXNyLkfZ98C3DkPmmd9LwrBsmjuy4A50DkXAP hywl9vEf/cLKiZfETBXFhhDl8CixG89F2ApyJ35EAf8Jw+lvHKw7w62GE3NyStcwiZ6R TocMMDXXvheNprZ1f0mNWLPd88Kr+qC7GkMhTC1zOcD2p5L4FwrnZ7j8Abynnuy9m0MB 4nFeXjCasKdBe3+CT0jJ3t4H2yc74ceaT/FYcvh+I8pT7HmgMoDGu1P25nFn0kQ6t5YF 0g6Q== X-Gm-Message-State: AO0yUKXjrsdbW6fripQStu8jg6LId2Ba1elueuYvzMhDoyaWgGzMo/fr +hkmOQP51e0zirnCKbR01dLpmw== X-Google-Smtp-Source: AK7set8wmFHPPBOnWsgzLkeL9htLP0DVsPY5yz7OdPjivFZ8aFP87xVFCGCYOgc1h6SZRbkdHknUAA== X-Received: by 2002:a05:600c:4f07:b0:3df:7948:886b with SMTP id l7-20020a05600c4f0700b003df7948886bmr2843138wmq.31.1676486031335; Wed, 15 Feb 2023 10:33:51 -0800 (PST) Received: from Mindolluin.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id s9-20020a05600c45c900b003e00c9888besm3196306wmo.30.2023.02.15.10.33.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Feb 2023 10:33:50 -0800 (PST) From: Dmitry Safonov To: linux-kernel@vger.kernel.org, David Ahern , Eric Dumazet , Paolo Abeni , Jakub Kicinski , "David S. Miller" Cc: Dmitry Safonov , Andy Lutomirski , Ard Biesheuvel , Bob Gilligan , Dan Carpenter , David Laight , Dmitry Safonov <0x7f454c46@gmail.com>, Eric Biggers , "Eric W. Biederman" , Francesco Ruggeri , Herbert Xu , Hideaki YOSHIFUJI , Ivan Delalande , Leonard Crestez , Salam Noureddine , netdev@vger.kernel.org, Francesco Ruggeri Subject: [PATCH v4 04/21] net/tcp: Prevent TCP-MD5 with TCP-AO being set Date: Wed, 15 Feb 2023 18:33:18 +0000 Message-Id: <20230215183335.800122-5-dima@arista.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230215183335.800122-1-dima@arista.com> References: <20230215183335.800122-1-dima@arista.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Be as conservative as possible: if there is TCP-MD5 key for a given peer regardless of L3 interface - don't allow setting TCP-AO key for the same peer. According to RFC5925, TCP-AO is supposed to replace TCP-MD5 and there can't be any switch between both on any connected tuple. Later it can be relaxed, if there's a use, but in the beginning restrict any intersection. Note: it's still should be possible to set both TCP-MD5 and TCP-AO keys on a listening socket for *different* peers. Co-developed-by: Francesco Ruggeri Signed-off-by: Francesco Ruggeri Co-developed-by: Salam Noureddine Signed-off-by: Salam Noureddine Signed-off-by: Dmitry Safonov --- include/net/tcp.h | 24 ++++++++++++++++++++++-- include/net/tcp_ao.h | 15 +++++++++++++++ net/ipv4/tcp_ao.c | 12 ++++++++++++ net/ipv4/tcp_ipv4.c | 12 +++++++++--- net/ipv4/tcp_output.c | 36 ++++++++++++++++++++++++++++++++++++ net/ipv6/tcp_ao.c | 17 +++++++++++++++++ net/ipv6/tcp_ipv6.c | 22 ++++++++++++++++++---- 7 files changed, 129 insertions(+), 9 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index fb18558053cc..2673cc8e5ed5 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1701,6 +1701,7 @@ int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family, u8 prefixlen, int l3index, u8 flags); +void tcp_clear_md5_list(struct sock *sk); struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, const struct sock *addr_sk); @@ -1709,14 +1710,23 @@ struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, extern struct static_key_false_deferred tcp_md5_needed; struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, const union tcp_md5_addr *addr, - int family); + int family, bool any_l3index); static inline struct tcp_md5sig_key * tcp_md5_do_lookup(const struct sock *sk, int l3index, const union tcp_md5_addr *addr, int family) { if (!static_branch_unlikely(&tcp_md5_needed.key)) return NULL; - return __tcp_md5_do_lookup(sk, l3index, addr, family); + return __tcp_md5_do_lookup(sk, l3index, addr, family, false); +} + +static inline struct tcp_md5sig_key * +tcp_md5_do_lookup_any_l3index(const struct sock *sk, + const union tcp_md5_addr *addr, int family) +{ + if (!static_branch_unlikely(&tcp_md5_needed.key)) + return NULL; + return __tcp_md5_do_lookup(sk, 0, addr, family, true); } enum skb_drop_reason @@ -1734,6 +1744,13 @@ tcp_md5_do_lookup(const struct sock *sk, int l3index, return NULL; } +static inline struct tcp_md5sig_key * +tcp_md5_do_lookup_any_l3index(const struct sock *sk, + const union tcp_md5_addr *addr, int family) +{ + return NULL; +} + static inline enum skb_drop_reason tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, const void *saddr, const void *daddr, @@ -2097,6 +2114,9 @@ struct tcp_sock_af_ops { int optname, sockptr_t optval, int optlen); + struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, + struct sock *addr_sk, + int sndid, int rcvid); #endif }; diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index 92c8c3ed42db..d817dac3bb0a 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -91,12 +91,27 @@ struct tcp_ao_info { int tcp_parse_ao(struct sock *sk, int cmd, unsigned short int family, sockptr_t optval, int optlen); void tcp_ao_destroy_sock(struct sock *sk); +struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, + const union tcp_ao_addr *addr, + int family, int sndid, int rcvid, u16 port); /* ipv4 specific functions */ int tcp_v4_parse_ao(struct sock *sk, int optname, sockptr_t optval, int optlen); +struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, + int sndid, int rcvid); /* ipv6 specific functions */ +struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk, + struct sock *addr_sk, + int sndid, int rcvid); int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen); #else +static inline struct tcp_ao_key *tcp_ao_do_lookup(const struct sock *sk, + const union tcp_ao_addr *addr, + int family, int sndid, int rcvid, u16 port) +{ + return NULL; +} + static inline void tcp_ao_destroy_sock(struct sock *sk) { } diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index 2dc8a3e946b1..4861ba9c89b9 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -165,6 +165,14 @@ void tcp_ao_destroy_sock(struct sock *sk) kfree_rcu(ao, rcu); } +struct tcp_ao_key *tcp_v4_ao_lookup(const struct sock *sk, struct sock *addr_sk, + int sndid, int rcvid) +{ + union tcp_ao_addr *addr = (union tcp_ao_addr *)&addr_sk->sk_daddr; + + return tcp_ao_do_lookup(sk, addr, AF_INET, sndid, rcvid, 0); +} + static int tcp_ao_current_rnext(struct sock *sk, u16 tcpa_flags, u8 tcpa_sndid, u8 tcpa_rcvid) { @@ -619,6 +627,10 @@ static int tcp_ao_add_cmd(struct sock *sk, unsigned short int family, if (cmd.tcpa_keyflags & ~TCP_AO_KEYF_ALL) return -EINVAL; + /* Don't allow keys for peers that have a matching TCP-MD5 key */ + if (tcp_md5_do_lookup_any_l3index(sk, addr, family)) + return -EKEYREJECTED; + ao_info = rcu_dereference_protected(tcp_sk(sk)->ao_info, lockdep_sock_is_held(sk)); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 60695942ee2b..b143f5f0ca38 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1073,7 +1073,7 @@ static bool better_md5_match(struct tcp_md5sig_key *old, struct tcp_md5sig_key * /* Find the Key structure for an address. */ struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, const union tcp_md5_addr *addr, - int family) + int family, bool any_l3index) { const struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *key; @@ -1092,7 +1092,8 @@ struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, lockdep_sock_is_held(sk)) { if (key->family != family) continue; - if (key->flags & TCP_MD5SIG_FLAG_IFINDEX && key->l3index != l3index) + if (!any_l3index && key->flags & TCP_MD5SIG_FLAG_IFINDEX && + key->l3index != l3index) continue; if (family == AF_INET) { mask = inet_make_mask(key->prefixlen); @@ -1304,7 +1305,7 @@ int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family, } EXPORT_SYMBOL(tcp_md5_do_del); -static void tcp_clear_md5_list(struct sock *sk) +void tcp_clear_md5_list(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *key; @@ -1374,6 +1375,10 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname, if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) return -EINVAL; + /* Don't allow keys for peers that have a matching TCP-AO key */ + if (tcp_ao_do_lookup(sk, addr, AF_INET, -1, -1, 0)) + return -EKEYREJECTED; + return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags, cmd.tcpm_key, cmd.tcpm_keylen); } @@ -2268,6 +2273,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { .md5_parse = tcp_v4_parse_md5_keys, #endif #ifdef CONFIG_TCP_AO + .ao_lookup = tcp_v4_ao_lookup, .ao_parse = tcp_v4_parse_ao, #endif }; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 71d01cf3c13e..3fe291e4a6a2 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3839,6 +3839,42 @@ int tcp_connect(struct sock *sk) tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_CONNECT_CB, 0, NULL); +#if defined(CONFIG_TCP_MD5SIG) && defined(CONFIG_TCP_AO) + /* Has to be checked late, after setting daddr/saddr/ops. + * Return error if the peer has both a md5 and a tcp-ao key + * configured as this is ambiguous. + */ + if (unlikely(rcu_dereference_protected(tp->md5sig_info, + lockdep_sock_is_held(sk)))) { + bool needs_md5 = !!tp->af_specific->md5_lookup(sk, sk); + bool needs_ao = !!tp->af_specific->ao_lookup(sk, sk, -1, -1); + + if (needs_md5 && needs_ao) + return -EKEYREJECTED; + + /* If we have a matching md5 key and no matching tcp-ao key + * then free up ao_info if allocated. + */ + if (needs_md5) { + tcp_ao_destroy_sock(sk); + } else if (needs_ao) { + tcp_clear_md5_list(sk); + kfree(rcu_replace_pointer(tp->md5sig_info, NULL, + lockdep_sock_is_held(sk))); + } + } +#endif +#ifdef CONFIG_TCP_AO + if (unlikely(rcu_dereference_protected(tp->ao_info, + lockdep_sock_is_held(sk)))) { + /* Don't allow connecting if ao is configured but no + * matching key is found. + */ + if (!tp->af_specific->ao_lookup(sk, sk, -1, -1)) + return -EKEYREJECTED; + } +#endif + if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk)) return -EHOSTUNREACH; /* Routing failure or similar. */ diff --git a/net/ipv6/tcp_ao.c b/net/ipv6/tcp_ao.c index 049ddbabe049..a56ab0a9cf55 100644 --- a/net/ipv6/tcp_ao.c +++ b/net/ipv6/tcp_ao.c @@ -12,6 +12,23 @@ #include #include +struct tcp_ao_key *tcp_v6_ao_do_lookup(const struct sock *sk, + const struct in6_addr *addr, + int sndid, int rcvid) +{ + return tcp_ao_do_lookup(sk, (union tcp_ao_addr *)addr, AF_INET6, + sndid, rcvid, 0); +} + +struct tcp_ao_key *tcp_v6_ao_lookup(const struct sock *sk, + struct sock *addr_sk, + int sndid, int rcvid) +{ + struct in6_addr *addr = &addr_sk->sk_v6_daddr; + + return tcp_v6_ao_do_lookup(sk, addr, sndid, rcvid); +} + int tcp_v6_parse_ao(struct sock *sk, int cmd, sockptr_t optval, int optlen) { diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 9edb84eb457b..8b38c112affb 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -601,6 +601,7 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, { struct tcp_md5sig cmd; struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; + union tcp_ao_addr *addr; int l3index = 0; u8 prefixlen; u8 flags; @@ -655,13 +656,24 @@ static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) return -EINVAL; - if (ipv6_addr_v4mapped(&sin6->sin6_addr)) - return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], + if (ipv6_addr_v4mapped(&sin6->sin6_addr)) { + addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3]; + + /* Don't allow keys for peers that have a matching TCP-AO key */ + if (tcp_ao_do_lookup(sk, addr, AF_INET, -1, -1, 0)) + return -EKEYREJECTED; + return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags, cmd.tcpm_key, cmd.tcpm_keylen); + } + + addr = (union tcp_md5_addr *)&sin6->sin6_addr; + + /* Don't allow keys for peers that have a matching TCP-AO key */ + if (tcp_ao_do_lookup(sk, addr, AF_INET6, -1, -1, 0)) + return -EKEYREJECTED; - return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr, - AF_INET6, prefixlen, l3index, flags, + return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags, cmd.tcpm_key, cmd.tcpm_keylen); } @@ -1902,6 +1914,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { .md5_parse = tcp_v6_parse_md5_keys, #endif #ifdef CONFIG_TCP_AO + .ao_lookup = tcp_v6_ao_lookup, .ao_parse = tcp_v6_parse_ao, #endif }; @@ -1933,6 +1946,7 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { .md5_parse = tcp_v6_parse_md5_keys, #endif #ifdef CONFIG_TCP_AO + .ao_lookup = tcp_v6_ao_lookup, .ao_parse = tcp_v6_parse_ao, #endif };