bind9-host, avahi-daemon-check-dns.sh hang forever causes network connections to get stuck
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
avahi (Debian) |
Fix Released
|
Unknown
|
|||
avahi (Ubuntu) |
Fix Released
|
High
|
Trent Lloyd | ||
Bionic |
Fix Released
|
High
|
Trent Lloyd | ||
Cosmic |
Fix Released
|
High
|
Trent Lloyd | ||
bind9 (Ubuntu) |
Confirmed
|
High
|
Unassigned | ||
Bionic |
Confirmed
|
Undecided
|
Unassigned | ||
Cosmic |
Won't Fix
|
High
|
Unassigned | ||
openconnect (Ubuntu) |
Invalid
|
Undecided
|
Unassigned | ||
strongswan (Ubuntu) |
Invalid
|
Undecided
|
Unassigned |
Bug Description
[Impact]
* Network connections for some users fail (in some cases a direct interface, in others when connecting a VPN) because the 'host' command to check for .local in DNS called by /usr/lib/
[Test Case]
* Multiple people have been unable to create a reproducer on a generic machine (e.g. it does not occur in a VM), I have a specific machine I can reproduce it on (a Skull Canyon NUC with Intel I219-LM) by simply "ifdown br0; ifup br0" and there are clearly 10s of other users affected in varying circumstances that all involve the same symptoms but no clear test case exists. Best I can suggest is that I test the patch on my system to ensure it works as expected, and the change is only 1 line which is fairly easily auditible and understandable.
[Regression Potential]
* The change is a single line change to the shell script to call host with "timeout". When tested on working and non-working system this appears to function as expected. I believe the regression potential for this is subsequently low.
* In attempt to anticipate possible issues, I checked that the timeout command is in the same path (/usr/bin) as the host command that is already called without a path, and the coreutils package (which contains timeout) is an Essential package. I also checked that timeout is not a built-in in bash, for those that have changed /bin/sh to bash (just in case).
[Other Info]
* N/A
[Original Bug Description]
On 18.04 Openconnect connects successfully to any of multiple VPN concentrators but network traffic does not flow across the VPN tunnel connection. When testing on 16.04 this works flawlessly. This also worked on this system when it was on 17.10.
I have tried reducing the mtu of the tun0 network device but this has not resulted in me being able to successfully ping the IP address.
Example showing ping attempt to the IP of DNS server:
~$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.
nameserver 172.29.88.11
nameserver 127.0.0.53
liam@liam-lat:~$ netstat -nr
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 wlp2s0
105.27.198.106 192.168.1.1 255.255.255.255 UGH 0 0 0 wlp2s0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0
172.29.0.0 0.0.0.0 255.255.0.0 U 0 0 0 tun0
172.29.88.11 0.0.0.0 255.255.255.255 UH 0 0 0 tun0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 wlp2s0
liam@liam-lat:~$ ping 172.29.88.11
PING 172.29.88.11 (172.29.88.11) 56(84) bytes of data.
^C
--- 172.29.88.11 ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3054ms
ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: openconnect 7.08-3
ProcVersionSign
Uname: Linux 4.15.0-10-generic x86_64
ApportVersion: 2.20.8-0ubuntu10
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Wed Feb 28 22:11:33 2018
InstallationDate: Installed on 2017-06-15 (258 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: openconnect
UpgradeStatus: Upgraded to bionic on 2018-02-22 (6 days ago)
Related branches
- Andreas Hasenack (community): Approve
- Canonical Server: Pending requested
- git-ubuntu developers: Pending requested
-
Diff: 32 lines (+12/-1)2 files modifieddebian/avahi-daemon-check-dns.sh (+2/-1)
debian/changelog (+10/-0)
Changed in avahi (Debian): | |
status: | Unknown → New |
tags: | added: server-next |
Changed in avahi (Ubuntu Cosmic): | |
status: | In Progress → Fix Released |
tags: |
added: verification-done-bionic removed: verification-needed-bionic |
tags: | removed: server-next |
Changed in avahi (Debian): | |
status: | New → Fix Released |
Changed in bind9 (Ubuntu Cosmic): | |
status: | Confirmed → Won't Fix |
Status changed to 'Confirmed' because the bug affects multiple users.