[Bug 882878] Re: With IPv6 disabled, openssh will not forward X connections

[ChristianEhrhardt]

I don't like to delta for that with upstream agreement - as it is a hard change in behavior.
I checked latest openssh git and the code is still as-is.

@CJWatson - with your openssh experience - what do you think about
suggesting the Suse patch [1] or [2] - actually[3] is the latest version
of the same - to upstream?

[1]: https://bugzilla.novell.com/attachment.cgi?id=580591&action=diff
[2]: https://build.opensuse.org/package/view_file/openSUSE:Factory/openssh/openssh-6.5p1-X_forward_with_disabled_ipv6.patch?rev=1c09c84b8dda320105cf7b59928951c4
[3]: https://build.opensuse.org/package/view_file/openSUSE:Factory/openssh/openssh-7.2p2-X_forward_with_disabled_ipv6.patch?expand=1

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to openssh in Ubuntu.
https://bugs.launchpad.net/bugs/882878

Title:
  With IPv6 disabled, openssh will not forward X connections

Status in openssh package in Ubuntu:
  Confirmed
Status in openssh package in Debian:
  New
Status in openssh package in openSUSE:
  Fix Released

Bug description:
  If you disable IPv6 in /etc/sysctl.conf sshd will not forward X11.

  It logs the failue in /var/log/auth.log

  Oct 27 18:49:26 uscps002 sshd[14722]: Accepted password for root from 172.20.10.50 port 60322 ssh2
  Oct 27 18:49:26 uscps002 sshd[14722]: pam_unix(sshd:session): session opened for user root by (uid=0)
  Oct 27 18:49:27 uscps002 sshd[14722]: error: Failed to allocate internet-domain X11 display socket.

  Aparently the compiled sshd version will not try an ipv4 localhost if
  an ipv6 localhost does not exist.

  Placing the following line in /etc/ssh/sshd_config fixes the issue

  X11UseLocalHost no


  
  root at uscps002:/var/log# lsb_release -rd
  Description:	Ubuntu 11.10
  Release:	11.10
  root at uscps002:/var/log# 

  
  root at uscps002:/var/log# uname -a
  Linux uscps002 3.0.0-12-server #20-Ubuntu SMP Fri Oct 7 16:36:30 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/882878/+subscriptions