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 47F3BC433F5 for ; Fri, 18 Feb 2022 14:30:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236039AbiBROa3 (ORCPT ); Fri, 18 Feb 2022 09:30:29 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:47506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235491AbiBROa2 (ORCPT ); Fri, 18 Feb 2022 09:30:28 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 983F6B0E8A for ; Fri, 18 Feb 2022 06:30:11 -0800 (PST) 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 51016B8265D for ; Fri, 18 Feb 2022 14:30:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 67CDEC340E9; Fri, 18 Feb 2022 14:30:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1645194609; bh=H4p9cu7s5fXSYL8+TbOv0b6fWRxFU5cVcMHctV7Bvl0=; h=Subject:To:Cc:From:Date:From; b=pAmlV7F3xFL7tMlZLqiQ/OwPC3der+vmFQ2x+klQuMmNmTkykGgIKY/BBZXc1UjyE ooBWVfQ1tL4Mx4giSV5saaN+U5+zwRmbrpam24WMXBF7Nzcm6Jhqpv4g2oHxmwr03S qhCM5eM6lUSMHiQGYu8n4EBF6eEArRzqTaVJOm24= Subject: FAILED: patch "[PATCH] ipv6: per-netns exclusive flowlabel checks" failed to apply to 5.4-stable tree To: willemb@google.com, kuba@kernel.org, liu3101@purdue.edu Cc: From: Date: Fri, 18 Feb 2022 15:30:06 +0100 Message-ID: <164519460610840@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 0b0dff5b3b98c5c7ce848151df9da0b3cdf0cc8b Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Tue, 15 Feb 2022 11:00:37 -0500 Subject: [PATCH] ipv6: per-netns exclusive flowlabel checks Ipv6 flowlabels historically require a reservation before use. Optionally in exclusive mode (e.g., user-private). Commit 59c820b2317f ("ipv6: elide flowlabel check if no exclusive leases exist") introduced a fastpath that avoids this check when no exclusive leases exist in the system, and thus any flowlabel use will be granted. That allows skipping the control operation to reserve a flowlabel entirely. Though with a warning if the fast path fails: This is an optimization. Robust applications still have to revert to requesting leases if the fast path fails due to an exclusive lease. Still, this is subtle. Better isolate network namespaces from each other. Flowlabels are per-netns. Also record per-netns whether exclusive leases are in use. Then behavior does not change based on activity in other netns. Changes v2 - wrap in IS_ENABLED(CONFIG_IPV6) to avoid breakage if disabled Fixes: 59c820b2317f ("ipv6: elide flowlabel check if no exclusive leases exist") Link: https://lore.kernel.org/netdev/MWHPR2201MB1072BCCCFCE779E4094837ACD0329@MWHPR2201MB1072.namprd22.prod.outlook.com/ Reported-by: Congyu Liu Signed-off-by: Willem de Bruijn Tested-by: Congyu Liu Link: https://lore.kernel.org/r/20220215160037.1976072-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski diff --git a/include/net/ipv6.h b/include/net/ipv6.h index 3afcb128e064..92eec13d1693 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -393,17 +393,20 @@ static inline void txopt_put(struct ipv6_txoptions *opt) kfree_rcu(opt, rcu); } +#if IS_ENABLED(CONFIG_IPV6) struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label); extern struct static_key_false_deferred ipv6_flowlabel_exclusive; static inline struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label) { - if (static_branch_unlikely(&ipv6_flowlabel_exclusive.key)) + if (static_branch_unlikely(&ipv6_flowlabel_exclusive.key) && + READ_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl)) return __fl6_sock_lookup(sk, label) ? : ERR_PTR(-ENOENT); return NULL; } +#endif struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space, struct ip6_flowlabel *fl, diff --git a/include/net/netns/ipv6.h b/include/net/netns/ipv6.h index a4b550380316..6bd7e5a85ce7 100644 --- a/include/net/netns/ipv6.h +++ b/include/net/netns/ipv6.h @@ -77,9 +77,10 @@ struct netns_ipv6 { spinlock_t fib6_gc_lock; unsigned int ip6_rt_gc_expire; unsigned long ip6_rt_last_gc; + unsigned char flowlabel_has_excl; #ifdef CONFIG_IPV6_MULTIPLE_TABLES - unsigned int fib6_rules_require_fldissect; bool fib6_has_custom_rules; + unsigned int fib6_rules_require_fldissect; #ifdef CONFIG_IPV6_SUBTREES unsigned int fib6_routes_require_src; #endif diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c index aa673a6a7e43..ceb85c67ce39 100644 --- a/net/ipv6/ip6_flowlabel.c +++ b/net/ipv6/ip6_flowlabel.c @@ -450,8 +450,10 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq, err = -EINVAL; goto done; } - if (fl_shared_exclusive(fl) || fl->opt) + if (fl_shared_exclusive(fl) || fl->opt) { + WRITE_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl, 1); static_branch_deferred_inc(&ipv6_flowlabel_exclusive); + } return fl; done: