From patchwork Mon Jul 16 08:09:37 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wei Li X-Patchwork-Id: 171143 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9A71A2C00DB for ; Mon, 16 Jul 2012 18:10:33 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751290Ab2GPIKb (ORCPT ); Mon, 16 Jul 2012 04:10:31 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:9515 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750843Ab2GPIK2 (ORCPT ); Mon, 16 Jul 2012 04:10:28 -0400 X-IronPort-AV: E=Sophos;i="4.77,592,1336320000"; d="scan'208";a="5404339" Received: from unknown (HELO tang.cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 16 Jul 2012 16:09:31 +0800 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id q6G8AL1U004217; Mon, 16 Jul 2012 16:10:22 +0800 Received: from [127.0.0.1] ([10.167.225.252]) by fnstmail02.fnst.cn.fujitsu.com (Lotus Domino Release 8.5.3) with ESMTP id 2012071616100832-708448 ; Mon, 16 Jul 2012 16:10:08 +0800 Message-ID: <5003CC41.9080204@cn.fujitsu.com> Date: Mon, 16 Jul 2012 16:09:37 +0800 From: Li Wei User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko/20120312 Thunderbird/11.0 MIME-Version: 1.0 To: "David S. Miller" CC: netdev , Stephen Hemminger Subject: [PATCH] ipv6: fix incorrect route 'expires' value passed to userspace. X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/16 16:10:08, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/16 16:10:10, Serialize complete at 2012/07/16 16:10:10 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When userspace use RTM_GETROUTE to dump route table, with a already expired route entry, we always got an 'expires' value(2147157) calculated base on INT_MAX. The reason of this problem is in the following satement: rt->dst.expires - jiffies < INT_MAX gcc promoted the type of both sides of '<' to unsigned long, thus a small negative value would be considered greater than INT_MAX. This patch fix this by cast the result of subtraction to an 'int' which I think is large enough for the expires. Also we should do some fix in rtnl_put_cacheinfo() which use jiffies_to_clock_t(which take an unsigned log as parameter) to convert jiffies to clock_t to handle the negative expires. --- net/core/rtnetlink.c | 3 ++- net/ipv6/route.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 21318d1..f92f3d8 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -641,7 +641,8 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id, }; if (expires) - ci.rta_expires = jiffies_to_clock_t(expires); + ci.rta_expires = expires > 0 ? jiffies_to_clock_t(expires) + : -jiffies_to_clock_t(-expires); return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci); } diff --git a/net/ipv6/route.c b/net/ipv6/route.c index becb048..a7fec9d 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2516,7 +2516,7 @@ static int rt6_fill_node(struct net *net, goto nla_put_failure; if (!(rt->rt6i_flags & RTF_EXPIRES)) expires = 0; - else if (rt->dst.expires - jiffies < INT_MAX) + else if ((int)(rt->dst.expires - jiffies) < INT_MAX) expires = rt->dst.expires - jiffies; else expires = INT_MAX;