From patchwork Mon May 16 19:36:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 573864 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 79A57C4332F for ; Mon, 16 May 2022 19:43:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346009AbiEPTnS (ORCPT ); Mon, 16 May 2022 15:43:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42580 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346032AbiEPTms (ORCPT ); Mon, 16 May 2022 15:42:48 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F3513ED3C; Mon, 16 May 2022 12:41:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 36347B81610; Mon, 16 May 2022 19:41:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C514C385AA; Mon, 16 May 2022 19:41:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652730067; bh=fBLJJBa4HMdeOHZr3X0XZgfHZVV7cWYDol4q08834Zo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2PevbTgmTh5noRfno/eAfl0/2LvvRRm50XevKap5qYI2wFQZKPNBhcqwVkYP1o/MC L+19tNLs4homqN1kgPO9DeuYUbV0wqmxokFxMex5WLq9KIxSw0an2UPmEbkRtI78NZ m/GEaeyo+UjaJV5ZMe1cLklBveEYwqWMmemM2pSM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Moshe Kol , Yossi Gilad , Amit Klein , "Jason A. Donenfeld" , Willy Tarreau , Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 20/32] tcp: resalt the secret every 10 seconds Date: Mon, 16 May 2022 21:36:34 +0200 Message-Id: <20220516193615.372887470@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220516193614.773450018@linuxfoundation.org> References: <20220516193614.773450018@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit 4dfa9b438ee34caca4e6a4e5e961641807367f6f ] In order to limit the ability for an observer to recognize the source ports sequence used to contact a set of destinations, we should periodically shuffle the secret. 10 seconds looks effective enough without causing particular issues. Cc: Moshe Kol Cc: Yossi Gilad Cc: Amit Klein Cc: Jason A. Donenfeld Tested-by: Willy Tarreau Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/core/secure_seq.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c index af6ad467ed61..3a8128341e6a 100644 --- a/net/core/secure_seq.c +++ b/net/core/secure_seq.c @@ -22,6 +22,8 @@ static siphash_key_t net_secret __read_mostly; static siphash_key_t ts_secret __read_mostly; +#define EPHEMERAL_PORT_SHUFFLE_PERIOD (10 * HZ) + static __always_inline void net_secret_init(void) { net_get_random_once(&net_secret, sizeof(net_secret)); @@ -100,11 +102,13 @@ u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, const struct { struct in6_addr saddr; struct in6_addr daddr; + unsigned int timeseed; __be16 dport; } __aligned(SIPHASH_ALIGNMENT) combined = { .saddr = *(struct in6_addr *)saddr, .daddr = *(struct in6_addr *)daddr, - .dport = dport + .timeseed = jiffies / EPHEMERAL_PORT_SHUFFLE_PERIOD, + .dport = dport, }; net_secret_init(); return siphash(&combined, offsetofend(typeof(combined), dport), @@ -145,8 +149,10 @@ EXPORT_SYMBOL_GPL(secure_tcp_seq); u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport) { net_secret_init(); - return siphash_3u32((__force u32)saddr, (__force u32)daddr, - (__force u16)dport, &net_secret); + return siphash_4u32((__force u32)saddr, (__force u32)daddr, + (__force u16)dport, + jiffies / EPHEMERAL_PORT_SHUFFLE_PERIOD, + &net_secret); } EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral); #endif