Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754279AbeAAOuB (ORCPT + 1 other); Mon, 1 Jan 2018 09:50:01 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:47104 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933131AbeAAOry (ORCPT ); Mon, 1 Jan 2018 09:47:54 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefano Brivio , Matteo Croce , Erik Kline , Nicolas Dichtel , "David S. Miller" Subject: [PATCH 4.14 112/146] ipv6: set all.accept_dad to 0 by default Date: Mon, 1 Jan 2018 15:38:23 +0100 Message-Id: <20180101140140.200810821@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180101140123.743014891@linuxfoundation.org> References: <20180101140123.743014891@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicolas Dichtel [ Upstream commit 094009531612246d9e13f9e0c3ae2205d7f63a0a ] With commits 35e015e1f577 and a2d3f3e33853, the global 'accept_dad' flag is also taken into account (default value is 1). If either global or per-interface flag is non-zero, DAD will be enabled on a given interface. This is not backward compatible: before those patches, the user could disable DAD just by setting the per-interface flag to 0. Now, the user instead needs to set both flags to 0 to actually disable DAD. Restore the previous behaviour by setting the default for the global 'accept_dad' flag to 0. This way, DAD is still enabled by default, as per-interface flags are set to 1 on device creation, but setting them to 0 is enough to disable DAD on a given interface. - Before 35e015e1f57a7 and a2d3f3e33853: global per-interface DAD enabled [default] 1 1 yes X 0 no X 1 yes - After 35e015e1f577 and a2d3f3e33853: global per-interface DAD enabled [default] 1 1 yes 0 0 no 0 1 yes 1 0 yes - After this fix: global per-interface DAD enabled 1 1 yes 0 0 no [default] 0 1 yes 1 0 yes Fixes: 35e015e1f577 ("ipv6: fix net.ipv6.conf.all interface DAD handlers") Fixes: a2d3f3e33853 ("ipv6: fix net.ipv6.conf.all.accept_dad behaviour for real") CC: Stefano Brivio CC: Matteo Croce CC: Erik Kline Signed-off-by: Nicolas Dichtel Acked-by: Stefano Brivio Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/addrconf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -231,7 +231,7 @@ static struct ipv6_devconf ipv6_devconf .proxy_ndp = 0, .accept_source_route = 0, /* we do not accept RH0 by default. */ .disable_ipv6 = 0, - .accept_dad = 1, + .accept_dad = 0, .suppress_frag_ndisc = 1, .accept_ra_mtu = 1, .stable_secret = {