Comment 33 for bug 2011458

I have verified the fix using openssh 1:9.0p1-1ubuntu8.2 from lunar-proposed:

Test 1:

root@lunar:~# apt-cache policy openssh-server
openssh-server:
  Installed: 1:9.0p1-1ubuntu8.2
  Candidate: 1:9.0p1-1ubuntu8.2
  Version table:
 *** 1:9.0p1-1ubuntu8.2 500
        500 http://archive.ubuntu.com/ubuntu lunar-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     1:9.0p1-1ubuntu8 500
        500 http://archive.ubuntu.com/ubuntu lunar/main amd64 Packages
root@lunar:~# ssh localhost
The authenticity of host 'localhost (::1)' can't be established.
ED25519 key fingerprint is SHA256:pGn2A4yGeFN/7Rlk830HLUMQqsybaSmP36MPGpmKXmQ.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added 'localhost' (ED25519) to the list of known hosts.
Welcome to Ubuntu 23.04 (GNU/Linux 6.2.0-20-generic x86_64)

 * Documentation: https://help.ubuntu.com
 * Management: https://landscape.canonical.com
 * Support: https://ubuntu.com/advantage

The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

root@lunar:~# systemctl reload ssh
root@lunar:~# systemctl status ssh
● ssh.service - OpenBSD Secure Shell server
     Loaded: loaded (/lib/systemd/system/ssh.service; disabled; preset: enabled)
    Drop-In: /etc/systemd/system/ssh.service.d
             └─00-socket.conf
             /run/systemd/system/service.d
             └─zzz-lxc-service.conf
     Active: active (running) since Fri 2023-06-02 14:13:03 UTC; 11s ago
TriggeredBy: ● ssh.socket
       Docs: man:sshd(8)
             man:sshd_config(5)
    Process: 1030 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
    Process: 1062 ExecReload=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
    Process: 1063 ExecReload=/bin/kill -HUP $MAINPID (code=exited, status=0/SUCCESS)
   Main PID: 1031 (sshd)
      Tasks: 1 (limit: 18854)
     Memory: 3.2M
        CPU: 101ms
     CGroup: /system.slice/ssh.service
             └─1031 "sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups"

Jun 02 14:13:03 lunar systemd[1]: Starting ssh.service - OpenBSD Secure Shell server...
Jun 02 14:13:03 lunar sshd[1031]: Server listening on :: port 22.
Jun 02 14:13:03 lunar systemd[1]: Started ssh.service - OpenBSD Secure Shell server.
Jun 02 14:13:04 lunar sshd[1032]: Accepted publickey for root from ::1 port 53474 ssh2: RSA SHA256:KzrBiY2sWqLQ5WWGGUo>
Jun 02 14:13:04 lunar sshd[1032]: pam_unix(sshd:session): session opened for user root(uid=0) by (uid=0)
Jun 02 14:13:04 lunar sshd[1032]: pam_env(sshd:session): deprecated reading of user environment enabled
Jun 02 14:13:10 lunar systemd[1]: Reloading ssh.service - OpenBSD Secure Shell server...
Jun 02 14:13:10 lunar sshd[1031]: Received SIGHUP; restarting.
Jun 02 14:13:10 lunar systemd[1]: Reloaded ssh.service - OpenBSD Secure Shell server.
Jun 02 14:13:10 lunar sshd[1031]: Server listening on :: port 22.

Test 2:

root@lunar:~# vi /etc/default/ssh
root@lunar:~# cat /etc/default/ssh
# Default settings for openssh-server. This file is sourced by /bin/sh from
# /etc/init.d/ssh.

# Options to pass to sshd
SSHD_OPTS=-ddd
root@lunar:~# ssh localhost
Welcome to Ubuntu 23.04 (GNU/Linux 6.2.0-20-generic x86_64)

 * Documentation: https://help.ubuntu.com
 * Management: https://landscape.canonical.com
 * Support: https://ubuntu.com/advantage
Last login: Fri Jun 2 14:13:04 2023 from ::1
debug1: PAM: reinitializing credentials
debug1: permanently_set_uid: 0/0
debug3: Copy environment: XDG_SESSION_ID=111
debug3: Copy environment: XDG_RUNTIME_DIR=/run/user/0
debug3: Copy environment: DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/0/bus
debug3: Copy environment: XDG_SESSION_TYPE=tty
debug3: Copy environment: XDG_SESSION_CLASS=user
debug3: Copy environment: PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
debug3: Copy environment: LANG=en_US.UTF-8
Environment:
  LANG=en_US.UTF-8
  USER=root
  LOGNAME=root
  HOME=/root
  PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
  SHELL=/bin/bash
  TERM=xterm-256color
  XDG_SESSION_ID=111
  XDG_RUNTIME_DIR=/run/user/0
  DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/0/bus
  XDG_SESSION_TYPE=tty
  XDG_SESSION_CLASS=user
  SSH_CLIENT=::1 58114 22
  SSH_CONNECTION=::1 58114 ::1 22
  SSH_TTY=/dev/pts/2
root@lunar:~# systemctl status ssh
● ssh.service - OpenBSD Secure Shell server
     Loaded: loaded (/lib/systemd/system/ssh.service; disabled; preset: enabled)
    Drop-In: /etc/systemd/system/ssh.service.d
             └─00-socket.conf
             /run/systemd/system/service.d
             └─zzz-lxc-service.conf
     Active: active (running) since Fri 2023-06-02 14:14:30 UTC; 3s ago
TriggeredBy: ● ssh.socket
       Docs: man:sshd(8)
             man:sshd_config(5)
    Process: 146 ExecStartPre=/usr/sbin/sshd -t (code=exited, status=0/SUCCESS)
   Main PID: 147 (sshd)
      Tasks: 0 (limit: 18854)
     Memory: 1.8M
        CPU: 58ms
     CGroup: /system.slice/ssh.service
             ‣ 147 "sshd: root@pts/2"

Jun 02 14:14:31 lunar sshd[147]: debug1: server_input_channel_req: channel 0 request shell reply 1
Jun 02 14:14:31 lunar sshd[147]: debug1: session_by_channel: session 0 channel 0
Jun 02 14:14:31 lunar sshd[147]: debug1: session_input_channel_req: session 0 req shell
Jun 02 14:14:31 lunar sshd[147]: Starting session: shell on pts/2 for root from ::1 port 58114 id 0
Jun 02 14:14:31 lunar sshd[147]: debug2: fd 4 setting TCP_NODELAY
Jun 02 14:14:31 lunar sshd[147]: debug3: set_sock_tos: set socket 4 IPV6_TCLASS 0x10
Jun 02 14:14:31 lunar sshd[147]: debug2: channel 0: rfd 10 isatty
Jun 02 14:14:31 lunar sshd[147]: debug2: fd 10 setting O_NONBLOCK
Jun 02 14:14:31 lunar sshd[147]: debug3: fd 7 is O_NONBLOCK
Jun 02 14:14:31 lunar sshd[147]: debug3: send packet: type 99