Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 27A1743F089; Mon, 17 Aug 2026 14:54:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786978492; cv=none; b=Zz9uzYMkRldB9GOfYZLD8yoQptc2vcPNylYQ0syR8mQjCKxqu3RW/ZiDWXj31ZBFX3AJQs0E1AzF2TWMg9B0eUE/a8rBFX7AoN9jGyWtyg8EE8DWDzEaNyEGZC6RKJUQ51qo6+XZI/AUkmkEAI0JGphR8nBWJQbXjaFnnKawa7I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786978492; c=relaxed/simple; bh=Jnn1Ew0UxBAoPFgaUs+y5MAXrI3krWz8DyC0ERBQifg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FqHzlbDTA183I7wJ6FUJMCv/sesYwwRUat2MZuhQR6053jVP/gRI7nF2mpKh+4s7kHb9EaObvAbhiaYYtsO/zpWgQUlQ8uWPMVjdwPKkBJH5PHWwDxgvU/HA57xtkvPmRtuU6CI7T9Boh6GD3sA7DuExF97twJ2eDO+iyhW9/ag= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=wGQhSeKH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="wGQhSeKH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EA001F00A3A; Mon, 17 Aug 2026 14:54:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786978490; bh=RqRRdGv5gPsr/f0MRh/HCmwQuSL805UpDkhJg+K1M0A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=wGQhSeKHwQ1UAObegquusRF/aFuzIrZC8dHzDlyIWZKHNwo8sgsLH6zGzDvguigDx ZEwdBTVwmqPz9gk3kEOMb61mBkUuBl0ihYA8wS47lJzE5WscWg7mBv7pS5NU9Hlt42 30pex8Du9lTMuW3vKJ0a7BbTo1QEdj6qVES0QnZ8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Francesco Ruggeri , Salam Noureddine , Dmitry Safonov , David Ahern , "David S. Miller" , Sasha Levin Subject: [PATCH 6.6 055/156] net/tcp: Add TCP-AO config and structures Date: Mon, 17 Aug 2026 15:33:09 +0200 Message-ID: <20260817132536.742310657@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132534.666299318@linuxfoundation.org> References: <20260817132534.666299318@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dmitry Safonov [ Upstream commit c845f5f3590ef4669fe5464f8a42be6442cd174b ] Introduce new kernel config option and common structures as well as helpers to be used by TCP-AO code. 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 Acked-by: David Ahern Signed-off-by: David S. Miller Stable-dep-of: d0c80dbb9704 ("net/atm: fix slab-out-of-bounds read in vcc_setsockopt()") Signed-off-by: Sasha Levin --- include/linux/tcp.h | 9 +++- include/net/tcp.h | 8 +--- include/net/tcp_ao.h | 90 ++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/tcp.h | 2 + net/ipv4/Kconfig | 13 ++++++ 5 files changed, 114 insertions(+), 8 deletions(-) create mode 100644 include/net/tcp_ao.h diff --git a/include/linux/tcp.h b/include/linux/tcp.h index e15452df9804f..c38778b0baa05 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -445,13 +445,18 @@ struct tcp_sock { bool syn_smc; /* SYN includes SMC */ #endif -#ifdef CONFIG_TCP_MD5SIG -/* TCP AF-Specific parts; only used by MD5 Signature support so far */ +#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) +/* TCP AF-Specific parts; only used by TCP-AO/MD5 Signature support so far */ const struct tcp_sock_af_ops *af_specific; +#ifdef CONFIG_TCP_MD5SIG /* TCP MD5 Signature Option information */ struct tcp_md5sig_info __rcu *md5sig_info; #endif +#ifdef CONFIG_TCP_AO + struct tcp_ao_info __rcu *ao_info; +#endif +#endif /* TCP fastopen related information */ struct tcp_fastopen_request *fastopen_req; diff --git a/include/net/tcp.h b/include/net/tcp.h index 9c3ec3200e27b..0eb9341f74888 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -1681,12 +1682,7 @@ static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) tp->retransmit_skb_hint = NULL; } -union tcp_md5_addr { - struct in_addr a4; -#if IS_ENABLED(CONFIG_IPV6) - struct in6_addr a6; -#endif -}; +#define tcp_md5_addr tcp_ao_addr /* - key database */ struct tcp_md5sig_key { diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h new file mode 100644 index 0000000000000..af76e1c47bea9 --- /dev/null +++ b/include/net/tcp_ao.h @@ -0,0 +1,90 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef _TCP_AO_H +#define _TCP_AO_H + +#define TCP_AO_KEY_ALIGN 1 +#define __tcp_ao_key_align __aligned(TCP_AO_KEY_ALIGN) + +union tcp_ao_addr { + struct in_addr a4; +#if IS_ENABLED(CONFIG_IPV6) + struct in6_addr a6; +#endif +}; + +struct tcp_ao_hdr { + u8 kind; + u8 length; + u8 keyid; + u8 rnext_keyid; +}; + +struct tcp_ao_key { + struct hlist_node node; + union tcp_ao_addr addr; + u8 key[TCP_AO_MAXKEYLEN] __tcp_ao_key_align; + unsigned int tcp_sigpool_id; + unsigned int digest_size; + u8 prefixlen; + u8 family; + u8 keylen; + u8 keyflags; + u8 sndid; + u8 rcvid; + u8 maclen; + struct rcu_head rcu; + u8 traffic_keys[]; +}; + +static inline u8 *rcv_other_key(struct tcp_ao_key *key) +{ + return key->traffic_keys; +} + +static inline u8 *snd_other_key(struct tcp_ao_key *key) +{ + return key->traffic_keys + key->digest_size; +} + +static inline int tcp_ao_maclen(const struct tcp_ao_key *key) +{ + return key->maclen; +} + +static inline int tcp_ao_len(const struct tcp_ao_key *key) +{ + return tcp_ao_maclen(key) + sizeof(struct tcp_ao_hdr); +} + +static inline unsigned int tcp_ao_digest_size(struct tcp_ao_key *key) +{ + return key->digest_size; +} + +static inline int tcp_ao_sizeof_key(const struct tcp_ao_key *key) +{ + return sizeof(struct tcp_ao_key) + (key->digest_size << 1); +} + +struct tcp_ao_info { + /* List of tcp_ao_key's */ + struct hlist_head head; + /* current_key and rnext_key aren't maintained on listen sockets. + * Their purpose is to cache keys on established connections, + * saving needless lookups. Never dereference any of them from + * listen sockets. + * ::current_key may change in RX to the key that was requested by + * the peer, please use READ_ONCE()/WRITE_ONCE() in order to avoid + * load/store tearing. + * Do the same for ::rnext_key, if you don't hold socket lock + * (it's changed only by userspace request in setsockopt()). + */ + struct tcp_ao_key *current_key; + struct tcp_ao_key *rnext_key; + u32 flags; + __be32 lisn; + __be32 risn; + struct rcu_head rcu; +}; + +#endif /* _TCP_AO_H */ diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index d1d08da6331ab..bf93a80809d6a 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -360,6 +360,8 @@ struct tcp_diag_md5sig { __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; }; +#define TCP_AO_MAXKEYLEN 80 + /* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */ #define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1 diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig index 89e2ab023272f..8e94ed7c56a0e 100644 --- a/net/ipv4/Kconfig +++ b/net/ipv4/Kconfig @@ -744,6 +744,19 @@ config DEFAULT_TCP_CONG config TCP_SIGPOOL tristate +config TCP_AO + bool "TCP: Authentication Option (RFC5925)" + select CRYPTO + select TCP_SIGPOOL + depends on 64BIT && IPV6 != m # seq-number extension needs WRITE_ONCE(u64) + help + TCP-AO specifies the use of stronger Message Authentication Codes (MACs), + protects against replays for long-lived TCP connections, and + provides more details on the association of security with TCP + connections than TCP MD5 (See RFC5925) + + If unsure, say N. + config TCP_MD5SIG bool "TCP: MD5 Signature Option support (RFC2385)" select CRYPTO -- 2.53.0