From mboxrd@z Thu Jan 1 00:00:00 1970 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 51E7FC433F5 for ; Sun, 24 Apr 2022 19:37:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239456AbiDXTkO (ORCPT ); Sun, 24 Apr 2022 15:40:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238900AbiDXTkK (ORCPT ); Sun, 24 Apr 2022 15:40:10 -0400 Received: from mail-yb1-xb2c.google.com (mail-yb1-xb2c.google.com [IPv6:2607:f8b0:4864:20::b2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5547A369DF for ; Sun, 24 Apr 2022 12:37:09 -0700 (PDT) Received: by mail-yb1-xb2c.google.com with SMTP id r189so23628047ybr.6 for ; Sun, 24 Apr 2022 12:37:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YnAouN3/QaYFQRA8k13sFCBqmUwn7Rgk9ylA4812FH8=; b=c6Em+6CnMcjxwIpmPMF3mQtrjKK1n945ZGOqB2TSqSUOMdIcu6cu/8GQFKj9K02tht wTmKciCz18mtlFc/a4tRAO5YLUunRb99GWyqzWupZi0PwIVgqtTivE5mEL29JvKLE4Bm /BM/rUBriv3TzWh94cx/POpRvspabs4G6hBqjYKdMRC74S25kqA2ApVPtkmnUNYMg4aK q6bUvpH8of+oT8hzjDTBhniZDOPN8r8idVPwaCMlDzgKQarSo8BRRv/v/c97/Q5uPYRq ucMcz+oI/DNPTjsnwjXrDSH07+aGOR6NX4qv8QrASThiwosqMIT+ECB4dXvZyU0DtRjo 7+vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=YnAouN3/QaYFQRA8k13sFCBqmUwn7Rgk9ylA4812FH8=; b=TL2xZQFuwsOIYApWg4ZEQx/J9fZRGiNWCGy/yK7p1mfqspDY8hpTdXQ+Gm7KxTldpf 01UJZrytTNMUwAo5MFBBRjG9upQrf8MM3MWqcAYhzNjEKPa1M6kNXs3JAPHGpo8GGWU9 KOeUhAZlvc276VUsB1bKeyJTfDponrpa/fyWEAVfrUsRrXllvgBpCzaWmZ5RvWeVna3J oPzh1b8+b9kafmBruKSWghasanNkqej/Nu/22Ljw8hkjiyvl+iNmYtL+80531Rv8vSHy tSGqLe6Bnbp2ypOX6CaHMMoh2cUaqbULP+qWR58yjBnF+68O+eVl6++sJgOCGAXzAMWz ugBQ== X-Gm-Message-State: AOAM530VhHFdz4lMFJPMycKQjMhhbythr511DoWp3yY12G6YrBvN4+pV tWJDKRxqggyZoyjL1tZqxUa65916w+67vOg+wAc7yw== X-Google-Smtp-Source: ABdhPJxPee0rQQxRVcJIKv7ARIsp8dN+dBXkPrOltW7JPYE4strNgNlr+7QNfAU8CKBa6dZD3jpZYe8+5LsV3O60wBM= X-Received: by 2002:a05:6902:c9:b0:641:1998:9764 with SMTP id i9-20020a05690200c900b0064119989764mr13153900ybs.427.1650829028283; Sun, 24 Apr 2022 12:37:08 -0700 (PDT) MIME-Version: 1.0 References: <20220421005026.686A45EC01F2@us226.sjc.aristanetworks.com> In-Reply-To: <20220421005026.686A45EC01F2@us226.sjc.aristanetworks.com> From: Eric Dumazet Date: Sun, 24 Apr 2022 12:36:57 -0700 Message-ID: Subject: Re: [PATCH v2 net] tcp: md5: incorrect tcp_header_len for incoming connections To: Francesco Ruggeri Cc: Paolo Abeni , Jakub Kicinski , David Ahern , Hideaki YOSHIFUJI , David Miller , LKML , netdev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 20, 2022 at 5:50 PM Francesco Ruggeri wrote: > > In tcp_create_openreq_child we adjust tcp_header_len for md5 using the > remote address in newsk. But that address is still 0 in newsk at this > point, and it is only set later by the callers (tcp_v[46]_syn_recv_sock). > Use the address from the request socket instead. > > v2: Added "Fixes:" line. > > Fixes: cfb6eeb4c860 ("[TCP]: MD5 Signature Option (RFC2385) support.") > Signed-off-by: Francesco Ruggeri > --- > net/ipv4/tcp_minisocks.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c > index 6366df7aaf2a..6854bb1fb32b 100644 > --- a/net/ipv4/tcp_minisocks.c > +++ b/net/ipv4/tcp_minisocks.c > @@ -531,7 +531,7 @@ struct sock *tcp_create_openreq_child(const struct sock *sk, > newtp->tsoffset = treq->ts_off; > #ifdef CONFIG_TCP_MD5SIG > newtp->md5sig_info = NULL; /*XXX*/ > - if (newtp->af_specific->md5_lookup(sk, newsk)) > + if (treq->af_specific->req_md5_lookup(sk, req_to_sk(req))) Wait a minute. Are you sure treq->af_specific is initialized at this point ? I should have tested this one liner patch really :/ I think that for syncookies, treq->af_specific is not initialized, because we do not go through tcp_conn_request() helper, but instead use cookie_tcp_reqsk_alloc() Before your patch treq->af_specific was only used during SYNACK generation, which does not happen in syncookie more while receiving the third packet. I will test something like this patch. We could move the init after cookie_tcp_reqsk_alloc() has been called, but I prefer using the same construct than tcp_conn_request() diff --git a/include/net/tcp.h b/include/net/tcp.h index be712fb9ddd71b2b320356677f3aa1c6759e2698..9987b3fba9f202632916cc439af9d17f1e68bcd3 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -480,6 +480,7 @@ int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, u32 cookie); struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, + const struct tcp_request_sock_ops *af_ops, struct sock *sk, struct sk_buff *skb); #ifdef CONFIG_SYN_COOKIES diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 2cb3b852d14861231ac47f0b3e4daeb57682ffd2..f191bfa996d71f11ef786a0a3bcb8f737622d37a 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -281,6 +281,7 @@ bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt, EXPORT_SYMBOL(cookie_ecn_ok); struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, + const struct tcp_request_sock_ops *af_ops, struct sock *sk, struct sk_buff *skb) { @@ -297,6 +298,8 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, return NULL; treq = tcp_rsk(req); + /* treq->af_specific might be used to perform TCP_MD5 lookup */ + treq->af_specific = af_ops; treq->syn_tos = TCP_SKB_CB(skb)->ip_dsfield; #if IS_ENABLED(CONFIG_MPTCP) treq->is_mptcp = sk_is_mptcp(sk); @@ -364,7 +367,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) goto out; ret = NULL; - req = cookie_tcp_reqsk_alloc(&tcp_request_sock_ops, sk, skb); + req = cookie_tcp_reqsk_alloc(&tcp_request_sock_ops, + &tcp_request_sock_ipv4_ops, sk, skb); if (!req) goto out; diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index d1b61d00368e1f58725e9997f74a0b144901277e..9cc123f000fbcfbeff7728bfee5339d6dd6470f9 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -170,7 +170,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) goto out; ret = NULL; - req = cookie_tcp_reqsk_alloc(&tcp6_request_sock_ops, sk, skb); + req = cookie_tcp_reqsk_alloc(&tcp6_request_sock_ops, + &tcp_request_sock_ipv6_ops, sk, skb); if (!req) goto out;