Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751630AbeAPDux (ORCPT + 1 other); Mon, 15 Jan 2018 22:50:53 -0500 Received: from smtps.newmedia-net.de ([185.84.6.167]:35659 "EHLO webmail.newmedia-net.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751506AbeAPDuv (ORCPT ); Mon, 15 Jan 2018 22:50:51 -0500 Subject: Re: [PATCH 4.9 27/75] net: igmp: Use correct source address on IGMPv3 reports To: Greg Kroah-Hartman , linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, Kevin Cernekee , Andrew Lunn , "David S. Miller" References: <20180101140056.475827799@linuxfoundation.org> <20180101140100.858496151@linuxfoundation.org> From: Sebastian Gottschall Message-ID: Date: Tue, 16 Jan 2018 04:50:39 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <20180101140100.858496151@linuxfoundation.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: please revert that on 4.9 and 4.14 it breaks igmp routing. it can be reproduced with any iptv connection using igmp-proxy. reverting this patch fixes the issue. Sebastian Am 01.01.2018 um 15:32 schrieb Greg Kroah-Hartman: > 4.9-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Kevin Cernekee > > > [ Upstream commit a46182b00290839fa3fa159d54fd3237bd8669f0 ] > > Closing a multicast socket after the final IPv4 address is deleted > from an interface can generate a membership report that uses the > source IP from a different interface. The following test script, run > from an isolated netns, reproduces the issue: > > #!/bin/bash > > ip link add dummy0 type dummy > ip link add dummy1 type dummy > ip link set dummy0 up > ip link set dummy1 up > ip addr add 10.1.1.1/24 dev dummy0 > ip addr add 192.168.99.99/24 dev dummy1 > > tcpdump -U -i dummy0 & > socat EXEC:"sleep 2" \ > UDP4-DATAGRAM:239.101.1.68:8889,ip-add-membership=239.0.1.68:10.1.1.1 & > > sleep 1 > ip addr del 10.1.1.1/24 dev dummy0 > sleep 5 > kill %tcpdump > > RFC 3376 specifies that the report must be sent with a valid IP source > address from the destination subnet, or from address 0.0.0.0. Add an > extra check to make sure this is the case. > > Signed-off-by: Kevin Cernekee > Reviewed-by: Andrew Lunn > Signed-off-by: David S. Miller > Signed-off-by: Greg Kroah-Hartman > --- > net/ipv4/igmp.c | 20 +++++++++++++++++++- > 1 file changed, 19 insertions(+), 1 deletion(-) > > --- a/net/ipv4/igmp.c > +++ b/net/ipv4/igmp.c > @@ -89,6 +89,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -321,6 +322,23 @@ igmp_scount(struct ip_mc_list *pmc, int > return scount; > } > > +/* source address selection per RFC 3376 section 4.2.13 */ > +static __be32 igmpv3_get_srcaddr(struct net_device *dev, > + const struct flowi4 *fl4) > +{ > + struct in_device *in_dev = __in_dev_get_rcu(dev); > + > + if (!in_dev) > + return htonl(INADDR_ANY); > + > + for_ifa(in_dev) { > + if (inet_ifa_match(fl4->saddr, ifa)) > + return fl4->saddr; > + } endfor_ifa(in_dev); > + > + return htonl(INADDR_ANY); > +} > + > static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu) > { > struct sk_buff *skb; > @@ -368,7 +386,7 @@ static struct sk_buff *igmpv3_newpack(st > pip->frag_off = htons(IP_DF); > pip->ttl = 1; > pip->daddr = fl4.daddr; > - pip->saddr = fl4.saddr; > + pip->saddr = igmpv3_get_srcaddr(dev, &fl4); > pip->protocol = IPPROTO_IGMP; > pip->tot_len = 0; /* filled in later */ > ip_select_ident(net, skb, NULL); > > > -- Mit freundlichen Grüssen / Regards Sebastian Gottschall / CTO NewMedia-NET GmbH - DD-WRT Firmensitz: Stubenwaldallee 21a, 64625 Bensheim Registergericht: Amtsgericht Darmstadt, HRB 25473 Geschäftsführer: Peter Steinhäuser, Christian Scheele http://www.dd-wrt.com email: s.gottschall@dd-wrt.com Tel.: +496251-582650 / Fax: +496251-5826565