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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B903C5518A for ; Wed, 22 Apr 2020 12:18:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3261420CC7 for ; Wed, 22 Apr 2020 12:18:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729290AbgDVMSv (ORCPT ); Wed, 22 Apr 2020 08:18:51 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:2872 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729017AbgDVMSK (ORCPT ); Wed, 22 Apr 2020 08:18:10 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 6D3479F84AA3A02A7E97; Wed, 22 Apr 2020 20:18:05 +0800 (CST) Received: from [127.0.0.1] (10.166.215.154) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.487.0; Wed, 22 Apr 2020 20:18:03 +0800 Subject: Re: [PATCH] xfrm: policy: Only use mark as policy lookup key To: Steffen Klassert References: <20200421143149.45108-1-yuehaibing@huawei.com> <20200422093344.GY13121@gauss3.secunet.de> CC: , , , , , From: Yuehaibing Message-ID: <1650fd55-dd70-f687-88b6-d32a04245915@huawei.com> Date: Wed, 22 Apr 2020 20:18:02 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20200422093344.GY13121@gauss3.secunet.de> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.166.215.154] X-CFilter-Loop: Reflected Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2020/4/22 17:33, Steffen Klassert wrote: > On Tue, Apr 21, 2020 at 10:31:49PM +0800, YueHaibing wrote: >> While update xfrm policy as follow: >> >> ip -6 xfrm policy update src fd00::1/128 dst fd00::2/128 dir in \ >> priority 1 mark 0 mask 0x10 >> ip -6 xfrm policy update src fd00::1/128 dst fd00::2/128 dir in \ >> priority 2 mark 0 mask 0x00 >> ip -6 xfrm policy update src fd00::1/128 dst fd00::2/128 dir in \ >> priority 2 mark 0 mask 0x10 >> >> We get this warning: >> >> WARNING: CPU: 0 PID: 4808 at net/xfrm/xfrm_policy.c:1548 >> Kernel panic - not syncing: panic_on_warn set ... >> CPU: 0 PID: 4808 Comm: ip Not tainted 5.7.0-rc1+ #151 >> Call Trace: >> RIP: 0010:xfrm_policy_insert_list+0x153/0x1e0 >> xfrm_policy_inexact_insert+0x70/0x330 >> xfrm_policy_insert+0x1df/0x250 >> xfrm_add_policy+0xcc/0x190 [xfrm_user] >> xfrm_user_rcv_msg+0x1d1/0x1f0 [xfrm_user] >> netlink_rcv_skb+0x4c/0x120 >> xfrm_netlink_rcv+0x32/0x40 [xfrm_user] >> netlink_unicast+0x1b3/0x270 >> netlink_sendmsg+0x350/0x470 >> sock_sendmsg+0x4f/0x60 >> >> Policy C and policy A has the same mark.v and mark.m, so policy A is >> matched in first round lookup while updating C. However policy C and >> policy B has same mark and priority, which also leads to matched. So >> the WARN_ON is triggered. >> >> xfrm policy lookup should only be matched when the found policy has the >> same lookup keys (mark.v & mark.m) no matter priority. >> >> Fixes: 7cb8a93968e3 ("xfrm: Allow inserting policies with matching mark and different priorities") >> Signed-off-by: YueHaibing >> --- >> net/xfrm/xfrm_policy.c | 16 +++++----------- >> 1 file changed, 5 insertions(+), 11 deletions(-) >> >> diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c >> index 297b2fd..67d0469 100644 >> --- a/net/xfrm/xfrm_policy.c >> +++ b/net/xfrm/xfrm_policy.c >> @@ -1436,13 +1436,7 @@ static void xfrm_policy_requeue(struct xfrm_policy *old, >> static bool xfrm_policy_mark_match(struct xfrm_policy *policy, >> struct xfrm_policy *pol) >> { >> - u32 mark = policy->mark.v & policy->mark.m; >> - >> - if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m) >> - return true; >> - >> - if ((mark & pol->mark.m) == pol->mark.v && >> - policy->priority == pol->priority) > > If you remove the priority check, you can't insert policies with matching > mark and different priorities anymore. This brings us back the old bug. Yes, this is true. > > I plan to apply the patch from Xin Long, this seems to be the right way > to address this problem. That still brings an issue, update like this: policy A (mark.v = 1, mark.m = 0, priority = 1) policy B (mark.v = 1, mark.m = 0, priority = 1) A and B will all in the list. So should do this: static bool xfrm_policy_mark_match(struct xfrm_policy *policy, struct xfrm_policy *pol) { - u32 mark = policy->mark.v & policy->mark.m; - - if (policy->mark.v == pol->mark.v && policy->mark.m == pol->mark.m) - return true; - - if ((mark & pol->mark.m) == pol->mark.v && + if ((policy->mark.v & policy->mark.m) == (pol->mark.v & pol->mark.m) && policy->priority == pol->priority) return true; > > . >