[LightDM] LightDM preloads all users from LDAP

[Kamil Wilczek]

Dear Users,

I setup a Debian Bullseye system with users database in LDAP. I can
successfully log in, but I have problems with the LightDM.

On the greeter GUI page when I try to change the focus from the login
field to the password field, the form freezes and I cannot do
anything for about 20-30 seconds, then focus changes to password field
as expected.

In logs I can see that behind the scenes LightDM loads/adds *all* users
from my LDAP. All of them, about 10k.

How to disable this behaviour? Is this an expected behaviour?



I tried this configuration, but it didn't change anything:

# lightdm --show-config
    [Seat:*]
A  greeter-session=lightdm-greeter
B  greeter-hide-users=true
B  session-wrapper=/etc/X11/Xsession
B  greeter-allow-guest=false
B  greeter-show-manual-login=true
B  greeter-show-remote-login=false
B  allow-guest=false

Sources:
A  /usr/share/lightdm/lightdm.conf.d/01_debian.conf
B  /etc/lightdm/lightdm.conf



lightm.log shows (I did not set DEBUG anywhere, don't know where it
comes from):

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.26.0, UID=0 PID=523
[+0.00s] DEBUG: Loading configuration dirs from 
/usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from 
/usr/share/lightdm/lightdm.conf.d/01_debian.conf
[+0.00s] DEBUG: Loading configuration dirs from 
/usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from 
/etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Registered seat module unity
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: _g_io_module_get_default: Found default implementation 
local (GLocalVfs) for ‘gio-vfs’
[+0.01s] DEBUG: Monitoring logind for seats
[+0.01s] DEBUG: New seat added from logind: seat0
[+0.01s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.01s] DEBUG: Seat seat0 has property CanMultiSession=no
[+0.01s] DEBUG: Seat seat0: Starting
[+0.01s] DEBUG: Seat seat0: Creating greeter session
[+0.01s] DEBUG: Seat seat0: Creating display server of type x
[+0.02s] DEBUG: Seat seat0: Plymouth is running on VT 1, but this is 
less than the configured minimum of 7 so not replacing it
[+0.02s] DEBUG: Quitting Plymouth
[+0.04s] DEBUG: Using VT 7
[+0.04s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.04s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.05s] DEBUG: XServer 0: Writing X server authority to 
/var/run/lightdm/root/:0
[+0.05s] DEBUG: XServer 0: Launching X Server
[+0.05s] DEBUG: Launching process 543: /usr/bin/X :0 -seat seat0 -auth 
/var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.05s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.05s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.05s] DEBUG: Registering seat with bus path 
/org/freedesktop/DisplayManager/Seat0
[+0.05s] WARNING: Could not enumerate user data directory 
/var/lib/lightdm/data: Error opening directory '/var/lib/lightdm/data': 
No such file or directory
[+1.94s] DEBUG: Got signal 10 from process 543
[+1.94s] DEBUG: XServer 0: Got signal from X server :0
[+1.94s] DEBUG: XServer 0: Connecting to XServer :0
[+1.97s] DEBUG: Seat seat0: Display server ready, starting session 
authentication
[+1.97s] DEBUG: Session pid=599: Started with service 'lightdm-greeter', 
username 'lightdm'
[+7.82s] DEBUG: Session pid=599: Authentication complete with return 
value 0: Success
[+7.82s] DEBUG: Seat seat0: Session authenticated, running command
[+7.82s] DEBUG: Session pid=599: Running command 
/usr/sbin/lightdm-gtk-greeter
[+7.83s] WARNING: Error getting user list from org.freedesktop.Accounts: 
GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name 
org.freedesktop.Accounts was not provided by any .service files
[+7.83s] DEBUG: Loading user config from /etc/lightdm/users.conf
DEBUG: .. user ... added
DEBUG: .. user ... added
DEBUG: .. user ... added
DEBUG: .. user ... added
(10k times)
...


Kind Regards
-- 
Kamil Wilczek  [https://keys.openpgp.org/]
[D415917E84B8DA5A60E853B6E676ED061316B69B]


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