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 F1BA3C04FE0 for ; Tue, 1 Aug 2023 09:35:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232931AbjHAJfw (ORCPT ); Tue, 1 Aug 2023 05:35:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232854AbjHAJfa (ORCPT ); Tue, 1 Aug 2023 05:35:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A3CC1BC3 for ; Tue, 1 Aug 2023 02:33:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9B212614F3 for ; Tue, 1 Aug 2023 09:33:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4FC6C433C7; Tue, 1 Aug 2023 09:33:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690882405; bh=lZ2p+7a+qj1f2E9IkI7Z+84izdDVn1Ey2zd9Vxb21nE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gAecuPHl/imYZQIkZSgZIQy6dU3c3vIEDmAIc8nCPX8JGtY/ukKfddw7YtinE96ik iXJry6q1eHS9PzdWSyWhXANwR3MMCaT2J60jiYj19bcazn1APUYO50+nM5+XP6bvJc yTL605iPP+jO3H523qyeqnF+BkPzYRo4yt0ASOLM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jiri Pirko , Xiao Ma , =?UTF-8?q?Maciej=20=C5=BBenczykowski?= , David Ahern , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 094/228] ipv6 addrconf: fix bug where deleting a mngtmpaddr can create a new temporary address Date: Tue, 1 Aug 2023 11:19:12 +0200 Message-ID: <20230801091926.235895846@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230801091922.799813980@linuxfoundation.org> References: <20230801091922.799813980@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Maciej Żenczykowski [ Upstream commit 69172f0bcb6a09110c5d2a6d792627f5095a9018 ] currently on 6.4 net/main: # ip link add dummy1 type dummy # echo 1 > /proc/sys/net/ipv6/conf/dummy1/use_tempaddr # ip link set dummy1 up # ip -6 addr add 2000::1/64 mngtmpaddr dev dummy1 # ip -6 addr show dev dummy1 11: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 inet6 2000::44f3:581c:8ca:3983/64 scope global temporary dynamic valid_lft 604800sec preferred_lft 86172sec inet6 2000::1/64 scope global mngtmpaddr valid_lft forever preferred_lft forever inet6 fe80::e8a8:a6ff:fed5:56d4/64 scope link valid_lft forever preferred_lft forever # ip -6 addr del 2000::44f3:581c:8ca:3983/64 dev dummy1 (can wait a few seconds if you want to, the above delete isn't [directly] the problem) # ip -6 addr show dev dummy1 11: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 inet6 2000::1/64 scope global mngtmpaddr valid_lft forever preferred_lft forever inet6 fe80::e8a8:a6ff:fed5:56d4/64 scope link valid_lft forever preferred_lft forever # ip -6 addr del 2000::1/64 mngtmpaddr dev dummy1 # ip -6 addr show dev dummy1 11: dummy1: mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000 inet6 2000::81c9:56b7:f51a:b98f/64 scope global temporary dynamic valid_lft 604797sec preferred_lft 86169sec inet6 fe80::e8a8:a6ff:fed5:56d4/64 scope link valid_lft forever preferred_lft forever This patch prevents this new 'global temporary dynamic' address from being created by the deletion of the related (same subnet prefix) 'mngtmpaddr' (which is triggered by there already being no temporary addresses). Cc: Jiri Pirko Fixes: 53bd67491537 ("ipv6 addrconf: introduce IFA_F_MANAGETEMPADDR to tell kernel to manage temporary addresses") Reported-by: Xiao Ma Signed-off-by: Maciej Żenczykowski Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20230720160022.1887942-1-maze@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/addrconf.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 51bfc74805ecf..48a6486951cd6 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2561,12 +2561,18 @@ static void manage_tempaddrs(struct inet6_dev *idev, ipv6_ifa_notify(0, ift); } - if ((create || list_empty(&idev->tempaddr_list)) && - idev->cnf.use_tempaddr > 0) { + /* Also create a temporary address if it's enabled but no temporary + * address currently exists. + * However, we get called with valid_lft == 0, prefered_lft == 0, create == false + * as part of cleanup (ie. deleting the mngtmpaddr). + * We don't want that to result in creating a new temporary ip address. + */ + if (list_empty(&idev->tempaddr_list) && (valid_lft || prefered_lft)) + create = true; + + if (create && idev->cnf.use_tempaddr > 0) { /* When a new public address is created as described * in [ADDRCONF], also create a new temporary address. - * Also create a temporary address if it's enabled but - * no temporary address currently exists. */ read_unlock_bh(&idev->lock); ipv6_create_tempaddr(ifp, false); -- 2.39.2