Bug 273150

are you sure you didn't configure password-less logins? NoPassEnable and NoPassUsers in kdmrc. alternatively, you could get the same effect by using pam_permit in /etc/pam.d/kde (or whichever service kdm is configured to use).

Here are the configuration for kdmrc and /etc/pam.d/kde. Don't think no pass is enabled.

kde.pam
#%PAM-1.0
auth		required	pam_nologin.so
auth		required	pam_permit.so
account		required	pam_unix.so
password	required	pam_unix.so
session		required	pam_unix.so
session		required	pam_limits.so

kdmrc
[General]
ConfigVersion=2.4
ConsoleTTYs=tty1,tty2,tty3,tty4,tty5,tty6
PidFile=/var/run/kdm.pid
ReserveServers=:1,:2,:3
ServerVTs=-7
StaticServers=:0
AuthDir=/var/run/kdm
GreeterUID=kdm
DataDir=/var/lib/kdm

[Shutdown]
BootManager=None
HaltCmd=/sbin/halt
RebootCmd=/sbin/reboot

[X-*-Core]
AllowNullPasswd=false
AllowRootLogin=false
AllowShutdown=All
AutoReLogin=true
ClientLogFile=.xsession-errors-%d
Reset=/usr/share/config/kdm/Xreset
Session=/usr/share/config/kdm/Xsession
SessionsDirs=/usr/share/config/kdm/sessions,/usr/share/apps/kdm/sessions
Setup=/usr/share/config/kdm/Xsetup
Startup=/usr/share/config/kdm/Xstartup

[X-*-Greeter]
AntiAliasing=true
ColorScheme=
FaceSource=AdminOnly
FailFont=Sans Serif,10,-1,5,75,0,0,0,0,0
ForgingSeed=1232728347
GUIStyle=
GreetFont=Serif,20,-1,5,50,0,0,0,0,0
GreetString=Welcome to %s at %n
GreeterPos=50,50
HiddenUsers=root
Language=en_US
LogoArea=Logo
LogoPixmap=/usr/share/icons/kongoni.png
MaxShowUID=65000
MinShowUID=1000
Preloader=/usr/bin/preloadkde
SelectedUsers=
ShowUsers=NotHidden
SortUsers=true
StdFont=Sans Serif,10,-1,5,50,0,0,0,0,0
Theme=/usr/share/apps/kdm/themes/KongoniSpring
UseBackground=true
UseTheme=true
UserCompletion=false
UserList=true

[X-:*-Core]
AllowNullPasswd=true
AllowShutdown=All
NoPassEnable=false
NoPassUsers=
ServerArgsLocal=-nolisten tcp -dpi 96
ServerCmd=/usr/bin/X -br -quiet

[X-:*-Greeter]
AllowClose=false
DefaultUser=
FocusPasswd=true
LoginMode=DefaultLocal
PreselectUser=None

[X-:0-Core]
AutoLoginEnable=false
AutoLoginLocked=false
AutoLoginUser=
ClientLogFile=.xsession-errors

[Xdmcp]
Enable=false
Willing=/usr/share/config/kdm/Xwilling

OK, I think I found the issue:

This is wrong in /etc/pam.d/kde:

auth        required    pam_nologin.so
auth        required    pam_permit.so

should be:

auth        required    pam_nologin.so
auth        required    pam_unix.so

exactly.

note that there should be _also_ a kde-np pam service (which is used for automatic and password-less logins), which must contain pam_permit for obvious reasons. presumably, the two files got mixed up during installation/configuration.

Actually got a bit more stupid that that, kde-np was linked to kde pam setup and kde pam setup had what kde-np need it :)

On a different note, I got another issue with kdm, but this is not pam related:

klauncher(799) kdemain: No DBUS session-bus found. Check if you have started the DBUS server. 
kdeinit4: Communication error with launcher. Exiting!
kdmgreet(793)/kdecore (K*TimeZone*): KSystemTimeZones: ktimezoned initialize() D-Bus call failed:  "Not connected to D-Bus server" 

Do I open a new ticket? or can continue with this one?

always a new ticket.

but unless this is causing real problems, it's just noise. kdelibs makes it increasingly hard to run in kdm's non-session environment, so cut it some slack.

So shall I take it it's not an issue, just like you said noise?! and it can be totally ignored.

yes