package openssh-server 1:7.2p2-4ubuntu2.6 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[Norbert]

I have installed all updates to my system recently.
Then I tried to connect to this system from my LAN and was unable to connect.
So I tried to restart ssh service:

sudo service ssh restart
Job for ssh.service failed because the control process exited with error code. See "systemctl status ssh.service" and "journalctl -xe" for details.

фев 04 23:22:00 norbert-vaio systemd[1]: Failed to start OpenBSD Secure Shell server.
фев 04 23:22:00 norbert-vaio systemd[1]: ssh.service: Unit entered failed state.
фев 04 23:22:00 norbert-vaio systemd[1]: ssh.service: Failed with result 'exit-code'.
фев 04 23:22:00 norbert-vaio systemd[1]: ssh.service: Service hold-off time over, scheduling restart.
фев 04 23:22:00 norbert-vaio systemd[1]: Stopped OpenBSD Secure Shell server.
фев 04 23:22:00 norbert-vaio systemd[1]: ssh.service: Start request repeated too quickly.
фев 04 23:22:00 norbert-vaio systemd[1]: Failed to start OpenBSD Secure Shell server.
фев 04 23:22:00 norbert-vaio systemd[1]: ssh.service: Unit entered failed state.
фев 04 23:22:00 norbert-vaio systemd[1]: ssh.service: Failed with result 'start-limit-hit'.

Then I tried to reinstall it

$ sudo apt-get install --reinstall openssh-server
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0 B/335 kB of archives.
After this operation, 0 B of additional disk space will be used.
Preconfiguring packages ...
(Reading database ... 878149 files and directories currently installed.)
Preparing to unpack .../openssh-server_1%3a7.2p2-4ubuntu2.6_amd64.deb ...
Unpacking openssh-server (1:7.2p2-4ubuntu2.6) over (1:7.2p2-4ubuntu2.6) ...
Processing triggers for ureadahead (0.100.0-19) ...
Processing triggers for systemd (229-4ubuntu21.15) ...
Processing triggers for ufw (0.35-0ubuntu2) ...
WARN: uid is 0 but '/' is owned by 1004
WARN: / is group writable!
Processing triggers for man-db (2.7.5-1) ...
Setting up openssh-server (1:7.2p2-4ubuntu2.6) ...
Unsafe symlinks encountered in /var/run/sshd, refusing.
initctl: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused
insserv: warning: script 'screen-cleanup' missing LSB tags and overrides
insserv: Default-Start undefined, assuming empty start runlevel(s) for script `screen-cleanup'
insserv: Default-Stop undefined, assuming empty stop runlevel(s) for script `screen-cleanup'
initctl: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused
insserv: warning: script 'binfmt-support' missing LSB tags and overrides
insserv: Default-Start undefined, assuming empty start runlevel(s) for script `binfmt-support'
insserv: Default-Stop undefined, assuming empty stop runlevel(s) for script `binfmt-support'
Job for ssh.service failed because the control process exited with error code. See "systemctl status ssh.service" and "journalctl -xe" for details.
invoke-rc.d: initscript ssh, action "restart" failed.
● ssh.service - OpenBSD Secure Shell server
   Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
   Active: activating (auto-restart) (Result: exit-code) since Пн 2019-02-04 23:28:33 MSK; 9ms ago
  Process: 23843 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=255)
 Main PID: 23206 (code=exited, status=0/SUCCESS)

фев 04 23:28:33 norbert-vaio systemd[1]: Failed to start OpenBSD Secure Shell server.
фев 04 23:28:33 norbert-vaio systemd[1]: ssh.service: Unit entered failed state.
фев 04 23:28:33 norbert-vaio systemd[1]: ssh.service: Failed with result 'exit-code'.
dpkg: error processing package openssh-server (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 openssh-server
E: Sub-process /usr/bin/dpkg returned an error code (1)

and got this bug.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: openssh-server 1:7.2p2-4ubuntu2.6
ProcVersionSignature: Ubuntu 4.4.0-138.164-generic 4.4.155
Uname: Linux 4.4.0-138-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.18
AptOrdering:
 openssh-server: Install
 openssh-server: Configure
 NULL: ConfigurePending
Architecture: amd64
Date: Mon Feb 4 23:26:36 2019
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2010-12-05 (2983 days ago)
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.5
 apt 1.2.29ubuntu0.1
SourcePackage: openssh
Title: package openssh-server 1:7.2p2-4ubuntu2.6 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to xenial on 2017-06-24 (589 days ago)
modified.conffile..etc.ufw.applications.d.openssh-server: [deleted]

[Andreas Hasenack (ahasenack)]

Thanks for filing this bug in Ubuntu.

There are some interesting warnings in the logs you provided:

WARN: uid is 0 but '/' is owned by 1004
WARN: / is group writable!

and

Setting up openssh-server (1:7.2p2-4ubuntu2.6) ...
Unsafe symlinks encountered in /var/run/sshd, refusing.

More details should be present in /var/log/syslog, /var/log/auth.log and/or in the output of journalctl -xe.

Could you please inspect those and report back, or attach them to this bug?

[Norbert (nrbrtx)]

I have checked about 1004 and got:

    ls -ld /
    drwxrwxr-x 32 1004 1004 4096 Dec 9 23:22 /

- it is really strange.

So I ran

    sudo chown root: /
    ls -ld /
    drwxrwxr-x 32 root root 4096 Dec 9 23:22 /

And reinstalled SSHD again:

    sudo apt-get install --reinstall openssh-server

without errors:

$ systemctl status sshd.service
● ssh.service - OpenBSD Secure Shell server
   Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
   Active: active (running) since Ср 2019-02-06 22:02:53 MSK; 51s ago
  Process: 5011 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
 Main PID: 5031 (sshd)
   CGroup: /system.slice/ssh.service
           └─5031 /usr/sbin/sshd -D

Feb 06 22:02:53 norbert-vaio systemd[1]: Starting OpenBSD Secure Shell server...
Feb 06 22:02:53 norbert-vaio sshd[5031]: Server listening on 0.0.0.0 port 22.
Feb 06 22:02:53 norbert-vaio sshd[5031]: Server listening on :: port 22.
Feb 06 22:02:53 norbert-vaio systemd[1]: Started OpenBSD Secure Shell server.

then rebooted.

[Norbert (nrbrtx)]

Finally I have ran `sudo chmod g-w /` to be completely sure and rebooted again.
As the result I can connect to this machine from my LAN.

Just curious - why did I have 1004:1004 rights on /?

[Seth Arnold (seth-arnold)]

The easiest way to get that is to unpack a tarball, zip, package, etc., using sudo. Chances are really good *other* files and directories also have incorrect owner or permissions.

Thanks