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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 77591C43219 for ; Sat, 27 Apr 2019 15:24:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44265208C2 for ; Sat, 27 Apr 2019 15:24:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728355AbfD0PYm (ORCPT ); Sat, 27 Apr 2019 11:24:42 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33460 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727455AbfD0PP0 (ORCPT ); Sat, 27 Apr 2019 11:15:26 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hKP2x-00014G-Uw; Sat, 27 Apr 2019 16:15:24 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hKP2m-0004aY-FY; Sat, 27 Apr 2019 16:15:12 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "David S. Miller" , "Wenhao Zhang" , "Zhiqiang Liu" Date: Sat, 27 Apr 2019 16:13:09 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 147/202] net: fix IPv6 prefix route residue In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.66-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Zhiqiang Liu commit e75913c93f7cd5f338ab373c34c93a655bd309cb upstream. Follow those steps: # ip addr add 2001:123::1/32 dev eth0 # ip addr add 2001:123:456::2/64 dev eth0 # ip addr del 2001:123::1/32 dev eth0 # ip addr del 2001:123:456::2/64 dev eth0 and then prefix route of 2001:123::1/32 will still exist. This is because ipv6_prefix_equal in check_cleanup_prefix_route func does not check whether two IPv6 addresses have the same prefix length. If the prefix of one address starts with another shorter address prefix, even though their prefix lengths are different, the return value of ipv6_prefix_equal is true. Here I add a check of whether two addresses have the same prefix to decide whether their prefixes are equal. Fixes: 5b84efecb7d9 ("ipv6 addrconf: don't cleanup prefix route for IFA_F_NOPREFIXROUTE") Signed-off-by: Zhiqiang Liu Reported-by: Wenhao Zhang Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/ipv6/addrconf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -943,7 +943,8 @@ check_cleanup_prefix_route(struct inet6_ list_for_each_entry(ifa, &idev->addr_list, if_list) { if (ifa == ifp) continue; - if (!ipv6_prefix_equal(&ifa->addr, &ifp->addr, + if (ifa->prefix_len != ifp->prefix_len || + !ipv6_prefix_equal(&ifa->addr, &ifp->addr, ifp->prefix_len)) continue; if (ifa->flags & (IFA_F_PERMANENT | IFA_F_NOPREFIXROUTE))