dependency problem lightdm -> pam

[Hadmut Danisch]

Hi,

I've installed Lubuntu 18.04 and found that problem:

the display-manager service complains:

 ● lightdm.service - Light Display Manager
   Loaded: loaded (/lib/systemd/system/lightdm.service; indirect; vendor preset: enabled)
   Active: active (running) since Wed 2018-05-02 11:36:27 CEST; 1min 22s ago
     Docs: man:lightdm(1)
  Process: 1717 ExecStartPre=/bin/sh -c [ "$(basename $(cat /etc/X11/default-display-manager 2>/dev/null))" = "lightdm" ] (code=exited, status=0/SUCCESS)
 Main PID: 1720 (lightdm)
    Tasks: 6 (limit: 4915)
   CGroup: /system.slice/lightdm.service
           ├─1720 /usr/sbin/lightdm
           ├─1726 /usr/lib/xorg/Xorg -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
           └─1786 lightdm --session-child 12 19

Mai 02 11:36:29 pcdanisch lightdm[1735]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
Mai 02 11:36:29 pcdanisch lightdm[1735]: PAM adding faulty module: pam_kwallet5.so
Mai 02 11:36:29 pcdanisch lightdm[1735]: pam_unix(lightdm-greeter:session): session opened for user lightdm by (uid=0)
Mai 02 11:36:30 pcdanisch lightdm[1786]: PAM unable to dlopen(pam_gnome_keyring.so): /lib/security/pam_gnome_keyring.so: cannot open shared object file: No such file or directory
Mai 02 11:36:30 pcdanisch lightdm[1786]: PAM adding faulty module: pam_gnome_keyring.so
Mai 02 11:36:30 pcdanisch lightdm[1786]: PAM unable to dlopen(pam_kwallet.so): /lib/security/pam_kwallet.so: cannot open shared object file: No such file or directory
Mai 02 11:36:30 pcdanisch lightdm[1786]: PAM adding faulty module: pam_kwallet.so
Mai 02 11:36:30 pcdanisch lightdm[1786]: PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory
Mai 02 11:36:30 pcdanisch lightdm[1786]: PAM adding faulty module: pam_kwallet5.so
Mai 02 11:36:30 pcdanisch lightdm[1786]: pam_succeed_if(lightdm:auth): requirement "user ingroup nopasswdlogin" not met by user "danisch"

It's because /etc/pam.d/lightdm and /etc/pam.d/lightdm-greeter try to load pam modules which are not installed since there are not dependencies to libpam-gnome-keyring libpam-kwallet4 libpam-kwallet5

If it is not intended to let things run into error message (and possible further trouble), you should either remove these lines from the config files or add dependencies to pull in that packages.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: lightdm 1.26.0-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: LXDE
Date: Wed May 2 12:21:26 2018
InstallationDate: Installed on 2018-04-30 (2 days ago)
InstallationMedia: Lubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: lightdm
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Mélodie (meets)]

The following other bugs reports say the same thing: #1861598 and #1830079

I also find the same bug in Xubuntu 20.04 and in my own custom 20.04 Ubuntu. As the bug number here is the smallest, I'll assume it is the first one that has reported it.

I stumbled upon this bug while trying to find why some good computer would crash suddenly with Xubuntu 20.04. Another issue related to ACPI is probably what was happening, however looking out for other bugs while I am at it is something to be done. I also experience some crashes in my own computer at home where no ACPI issue is mentioned in the logs, but this “pam_kwallet*” related message is in my logs. (Not anymore next session because I commented out the lines in the /etc/pam.d/lightdm and lightdm-greeter files, but I know this might be a temporary turn-around if it is not fixed upstream, right?)

Now my first question is : what package does this bug belong to? Is is lightdm as it seems from this present bug report? I might say "yes", because wajig gives information about the packages pam_kwallet belong to, in particular, this part of the error message is interesting:

“ PAM adding faulty module: pam_kwallet.so ”

Well, there is no such file in the kwallet packages.

In details:

***
wajig whichpackage pam_kwallet
UNINSTALLED MATCHES (x3)
------------------------
libpam-kwallet5: /lib/x86_64-linux-gnu/security/pam_kwallet5.so
libpam-kwallet-common: /etc/xdg/autostart/pam_kwallet_init.desktop
libpam-kwallet-common: /usr/share/libpam-kwallet-common/pam_kwallet_init
***

what files do libpam-kwallet5 and libpam-kwallet-common bring in? The wajig command will also answer this question:
***
wajig listfiles libpam-kwallet5
libpam-kwallet5: /lib/x86_64-linux-gnu/security/pam_kwallet5.so
libpam-kwallet5: /usr/share/doc/libpam-kwallet5/changelog.Debian.gz
libpam-kwallet5: /usr/share/doc/libpam-kwallet5/copyright
***

So first thing first, the lines relating to "pam_kwallet.so" should just be removed from the files lightdm and lightdm-greeter, because it simply does not exist, so I guess this is why the message states it is a "faulty module".

As for the rest of the error message from the system, "PAM unable to dlopen(pam_kwallet5.so): /lib/security/pam_kwallet5.so: cannot open shared object file: No such file or directory"
I have no idea what can be done, but surely we need to do something about it.
Does PAM provide other types of conditions when it comes to try to load modules?

Or might there be another way to tell it not to try loading it if we are not in a KDE environment?

[Saverio Miroddi (64kramsystem)]

Still present in Focal and Jammy.