It looks like systemd is changing the mode (see argument=3) on VT1 on
logouts.
#define K_RAW 0x00
#define K_XLATE 0x01
#define K_MEDIUMRAW 0x02
#define K_UNICODE 0x04
#define K_OFF 0x04
#define KDGKBMODE 0x4B44 /* gets current keyboard mode */
#define KDSKBMODE 0x4B45 /* sets current keyboard mode */
test@test-Standard-PC-i440FX-PIIX-1996:~$ sudo sysdig evt.type=ioctl | grep
request=4B45
[sudo] password for test:
5657343 15:21:51.819076315 1 Xorg (1069) > ioctl fd=11(<f>/dev/tty1)
request=4B45 argument=4
5657453 15:21:51.820019063 0 systemd-logind (575) > ioctl fd=22(<f>/dev/tty1)
request=4B45 argument=3
5753055 15:21:52.771635876 0 systemd-logind (575) > ioctl fd=21(<f>/dev/tty1)
request=4B45 argument=4
20723813 15:49:41.368621972 1 systemd (23717) > ioctl fd=3(<f>/dev/tty2)
request=4B45 argument=3
22605710 15:53:04.107253025 1 systemd-logind (575) > ioctl fd=23(<f>/dev/tty3)
request=4B45 argument=4
22612602 15:53:04.142057934 1 Xorg (24089) > ioctl fd=11(<f>/dev/tty3)
request=4B45 argument=4
24077108 15:53:28.705600119 0 Xorg (24089) > ioctl fd=11(<f>/dev/tty3)
request=4B45 argument=4
24077278 15:53:28.706353493 1 systemd-logind (575) > ioctl fd=24(<f>/dev/tty3)
request=4B45 argument=3
24626343 15:53:58.336589416 0 systemd-logind (575) > ioctl fd=22(<f>/dev/tty1)
request=4B45 argument=3
24804326 15:53:59.385872243 0 systemd-logind (575) > ioctl fd=21(<f>/dev/tty1)
request=4B45 argument=4
25515114 15:54:12.915072995 1 systemd-logind (575) > ioctl fd=23(<f>/dev/tty3)
request=4B45 argument=4
25520504 15:54:12.929480424 1 Xorg (25112) > ioctl fd=11(<f>/dev/tty3)
request=4B45 argument=4
26921037 15:54:46.872029874 1 Xorg (25112) > ioctl fd=11(<f>/dev/tty3)
request=4B45 argument=4
26921239 15:54:46.872654795 1 systemd-logind (575) > ioctl fd=24(<f>/dev/tty3)
request=4B45 argument=3
27104852 15:54:53.870639078 1 systemd-logind (575) > ioctl fd=23(<f>/dev/tty3)
request=4B45 argument=4
27112208 15:54:53.894217722 1 Xorg (25697) > ioctl fd=11(<f>/dev/tty3)
request=4B45 argument=4
28677455 15:55:44.581119464 0 Xorg (25697) > ioctl fd=11(<f>/dev/tty3)
request=4B45 argument=4
28678288 15:55:44.592966138 1 systemd-logind (575) > ioctl fd=24(<f>/dev/tty3)
request=4B45 argument=3
** Also affects: systemd (Ubuntu)
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to systemd in Ubuntu.
https://bugs.launchpad.net/bugs/1803993
Title:
Password appears on the VT1 screen
Status in gdm3 package in Ubuntu:
Confirmed
Status in plymouth package in Ubuntu:
Confirmed
Status in systemd package in Ubuntu:
New
Bug description:
(continued from bug 1767918)
This was found when an administrative error made /home directory
inaccessible. Any users that tried to login after that, were not able
to (which is expected) but their password appears on the VT1 screen.
Under normal circumstances, VT1 is not visible. But once the system
was sent into this compromised mode, one can press ctrl+alt+F1 and
then ctrl+alt+F2 and get a momentary glance at VT1. One can keep
toggling between these key combinations in order to make out the
password(s) on VT1.
As a further test, I wanted to see if a non-super user could cause
this condition, and it is in fact possible. As a regular user, I made
their own home directory not writable and then removed ~/.config and
logged out. Then logged in as that user again, and although that user
can't login the system does go into that mode where passwords appear
on VT1 and are viewable with the key combinations mentioned herein.
Further, any other users that login will see no problem, but when they
logon their passwords also appear on VT1 and are viewable.
ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gdm3 3.28.3-0ubuntu18.04.3
Uname: Linux 4.19.2-041902-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Mon Nov 19 08:32:59 2018
InstallationDate: Installed on 2018-08-25 (85 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
ProcEnviron:
TERM=xterm-256color
PATH=(custom, no user)
XDG_RUNTIME_DIR=<set>
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: gdm3
UpgradeStatus: No upgrade log present (probably fresh install)
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1803993/+subscriptions
--
Mailing list: https://launchpad.net/~touch-packages
Post to : touch-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~touch-packages
More help : https://help.launchpad.net/ListHelp
