From nobody Wed Feb 11 12:07:23 2026 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 C6A02C7EE22 for ; Tue, 9 May 2023 22:16:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235513AbjEIWQc (ORCPT ); Tue, 9 May 2023 18:16:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235163AbjEIWQW (ORCPT ); Tue, 9 May 2023 18:16:22 -0400 Received: from mail-wm1-x331.google.com (mail-wm1-x331.google.com [IPv6:2a00:1450:4864:20::331]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EDE93AA3 for ; Tue, 9 May 2023 15:16:20 -0700 (PDT) Received: by mail-wm1-x331.google.com with SMTP id 5b1f17b1804b1-3f315712406so225563695e9.0 for ; Tue, 09 May 2023 15:16:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=google; t=1683670579; x=1686262579; 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=5EJY8QyVbpJhiPPm5kdYZASszxMCuGSjGBPUFVMUXvI=; b=FcjLRwJPwp06s9w82pX/hEkZrz5VOfCVr8glc6TOnWPf+LMM++AznMYK87XQS5co7y +4+YmedtGpd3XT+lF2S5FOOFzFcD1jLk/tEjfMVh5b5X9Lup1KkvIQRepDVQ7GHSYrJN rZNg3MXT522o93w68sSY3QzKK1RRscQorcBZXU2gEddOWpJt+W10X/6Pg7Anh1MbDD07 nFjJWAnW6d3kc1vddRzE5N9cipB5louiR7A4DfMMh58WzS38lnfV6v/WOgdTspHz6t3Y +TvoKX6KWNt07ETKyePmGCg2deRczsaKd5qPyQqWPq7feqFebU6KbWBtXfO4KPLjFTGM qruw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683670579; x=1686262579; 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=5EJY8QyVbpJhiPPm5kdYZASszxMCuGSjGBPUFVMUXvI=; b=OCn2CPynjXHijmH5PoGfB9uRwqNX33j08ABB3kqMzxmF/S09dhqPe2Oh987RraQNEb LtLMDv+3KJRn8X8z/2vInrLM+nkh6GT0ZJf0G+7x+rPB/tBTwcEojJVI0+WaQqvmWWux 5QQ9abYKZeoHL8ZFjht8GuSYQKVJmhRqPteohYod55ZmEyy8F6JCLeyZ3UhVsdF41ECg 3KoDZksdSbd/mgu+sLsX+gNsfRQxhFeSvoEbPAGb/qOCGJXE4wp/LJmtbI5SwCMrIYlY I3xJS1D0IzZIT3YbecQh2jLzJR35blsI7xunjclWj+Iy1PP/UsW+Bzpm4HrAjl81zk39 hi0A== X-Gm-Message-State: AC+VfDyvYqvRzV/U8sTZXOHGqSJNQkoXwLPVu2DpK5+kFuOksv7j/sTc YtqIVh7/s3rlV1yLnDWHhb0qfPqXRSH3+eErX64= X-Google-Smtp-Source: ACHHUZ4oKL1FJ8j955YZRxPMmcgVnkpvDuwo1LJcxMsaqA/A4/rFsAnUsMPungai8eg5gPgvvfbQNA== X-Received: by 2002:adf:f2ca:0:b0:307:8b6f:dcf1 with SMTP id d10-20020adff2ca000000b003078b6fdcf1mr8185594wrp.25.1683670578783; Tue, 09 May 2023 15:16:18 -0700 (PDT) Received: from Mindolluin.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id t25-20020a7bc3d9000000b003f42d3111b8sm2052888wmj.30.2023.05.09.15.16.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 May 2023 15:16:18 -0700 (PDT) From: Dmitry Safonov To: linux-kernel@vger.kernel.org, David Ahern , Eric Dumazet , Paolo Abeni , Jakub Kicinski , "David S. Miller" Cc: Dmitry Safonov , Dmitry Safonov <0x7f454c46@gmail.com>, Hideaki YOSHIFUJI , Leonard Crestez , Salam Noureddine , netdev@vger.kernel.org Subject: [RFC 3/5] net/tcp-md5: Verify inbound segments on twsk Date: Tue, 9 May 2023 23:16:06 +0100 Message-Id: <20230509221608.2569333-4-dima@arista.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230509221608.2569333-1-dima@arista.com> References: <20230509221608.2569333-1-dima@arista.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" It seems rare for BGP to have twsk socket and quite unlikely on server side, in addition I don't see any major concern of destroying twsk early by unsigned segments. But on the other hand, it seems better not to change TCP state by unsigned inbound segments and fixing this seems not hard. So, lets avoid replying or doing any TCP state changes as long as the segments weren't verified. Signed-off-by: Dmitry Safonov --- include/net/tcp.h | 7 ++++--- net/ipv4/tcp_ipv4.c | 9 +++++++-- net/ipv6/tcp_ipv6.c | 10 ++++++++-- 3 files changed, 19 insertions(+), 7 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index e127fc685ca6..db13dc7558f4 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1705,12 +1705,16 @@ extern struct static_key_false_deferred tcp_md5_nee= ded; struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3in= dex, const union tcp_md5_addr *addr, int family); + +#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) 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; + if (unlikely(sk->sk_state =3D=3D TCP_TIME_WAIT)) + return tcp_twsk_md5_key(tcp_twsk(sk)); return __tcp_md5_do_lookup(sk, l3index, addr, family); } =20 @@ -1718,9 +1722,6 @@ enum skb_drop_reason tcp_inbound_md5_hash(const struct sock *sk, const struct sk_buff *skb, const void *saddr, const void *daddr, int family, int dif, int sdif); - - -#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) #else static inline struct tcp_md5sig_key * tcp_md5_do_lookup(const struct sock *sk, int l3index, diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index b1056a4af60f..f5b870943dcb 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -676,7 +676,7 @@ static bool tcp_v4_md5_sign_reset(struct net *net, cons= t struct sock *sk, return !!hash_location; =20 rcu_read_lock(); - if (sk && sk_fullsock(sk)) { + if (sk && sk->sk_state !=3D TCP_NEW_SYN_RECV) { const union tcp_md5_addr *addr; int l3index; =20 @@ -2195,8 +2195,13 @@ int tcp_v4_rcv(struct sk_buff *skb) goto discard_it; =20 do_time_wait: - if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) drop_reason =3D SKB_DROP_REASON_XFRM_POLICY; + else + drop_reason =3D tcp_inbound_md5_hash(sk, skb, + &iph->saddr, &iph->daddr, + AF_INET, dif, sdif); + if (drop_reason) { inet_twsk_put(inet_twsk(sk)); goto discard_it; } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 574398a89970..3756a43367a3 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -987,7 +987,7 @@ static int tcp_v6_md5_lookup_reset_key(struct net *net,= const struct sock *sk, if (!static_branch_unlikely(&tcp_md5_needed.key)) return !!hash_location; =20 - if (sk && sk_fullsock(sk)) { + if (sk && sk->sk_state !=3D TCP_NEW_SYN_RECV) { /* sdif set, means packet ingressed via a device * in an L3 domain and inet_iif is set to it. */ @@ -1795,8 +1795,14 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buf= f *skb) goto discard_it; =20 do_time_wait: - if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { + if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) drop_reason =3D SKB_DROP_REASON_XFRM_POLICY; + else + drop_reason =3D tcp_inbound_md5_hash(sk, skb, + &hdr->saddr, &hdr->daddr, + AF_INET6, dif, sdif); + + if (drop_reason) { inet_twsk_put(inet_twsk(sk)); goto discard_it; } --=20 2.40.0