From patchwork Fri Jan 4 13:17:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 1020728 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=strlen.de Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43WQNx6wH5z9rxp for ; Sat, 5 Jan 2019 00:19:29 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728177AbfADNT3 (ORCPT ); Fri, 4 Jan 2019 08:19:29 -0500 Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:52510 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728173AbfADNT0 (ORCPT ); Fri, 4 Jan 2019 08:19:26 -0500 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.89) (envelope-from ) id 1gfPNj-0000rr-6g; Fri, 04 Jan 2019 14:19:23 +0100 From: Florian Westphal To: steffen.klassert@secunet.com Cc: xiyou.wangcong@gmail.com, , Florian Westphal Subject: [PATCH ipsec 5/7] xfrm: policy: fix reinsertion on node merge Date: Fri, 4 Jan 2019 14:17:03 +0100 Message-Id: <20190104131705.9550-6-fw@strlen.de> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190104131705.9550-1-fw@strlen.de> References: <20190104131705.9550-1-fw@strlen.de> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org "newpos" has wrong scope. It must be NULL on each iteration of the loop. Otherwise, when policy is to be inserted at the start, we would instead insert at point found by the previous loop-iteration instead. Also, we need to unlink the policy before we reinsert it to the new node, else we can get next-points-to-self loops. Because policies are only ordered by priority it is irrelevant which policy is "more recent" except when two policies have same priority. (the more recent one is placed after the older one). In these cases, we can use the ->pos id number to know which one is the 'older': the higher the id, the more recent the policy. So we only need to unlink all policies from the node that is about to be removed, and insert them to the replacement node. Fixes: 9cf545ebd591da ("xfrm: policy: store inexact policies in a tree ordered by destination address") Signed-off-by: Florian Westphal --- net/xfrm/xfrm_policy.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 24dfd1e47cf0..e691683223ee 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -823,13 +823,13 @@ static void xfrm_policy_inexact_list_reinsert(struct net *net, u16 family) { unsigned int matched_s, matched_d; - struct hlist_node *newpos = NULL; struct xfrm_policy *policy, *p; matched_s = 0; matched_d = 0; list_for_each_entry_reverse(policy, &net->xfrm.policy_all, walk.all) { + struct hlist_node *newpos = NULL; bool matches_s, matches_d; if (!policy->bydst_reinsert) @@ -839,7 +839,10 @@ static void xfrm_policy_inexact_list_reinsert(struct net *net, policy->bydst_reinsert = false; hlist_for_each_entry(p, &n->hhead, bydst) { - if (policy->priority >= p->priority) + if (policy->priority > p->priority) + newpos = &p->bydst; + else if (policy->priority == p->priority && + policy->pos > p->pos) newpos = &p->bydst; else break; @@ -955,12 +958,11 @@ static void xfrm_policy_inexact_node_merge(struct net *net, family); } - hlist_for_each_entry(tmp, &v->hhead, bydst) - tmp->bydst_reinsert = true; - hlist_for_each_entry(tmp, &n->hhead, bydst) + hlist_for_each_entry(tmp, &v->hhead, bydst) { tmp->bydst_reinsert = true; + hlist_del_rcu(&tmp->bydst); + } - INIT_HLIST_HEAD(&n->hhead); xfrm_policy_inexact_list_reinsert(net, n, family); }