KDE failed to unlock after locked

davidshen84 · Guru Joined: 09 Aug 2008 Posts: 315

Hi,

My system is KDE 5, Plasma, up to date. I can start and log in the DE successfully. But if I lock the screen, either by issue a screen lock or put the computer to sleep. I won't be able to unlock the screen.

The error is "Unlock failed". From the journal, it says authentication failed...but I am pretty sure I typed in the correct log in password, and I did not set a dedicated screen lock password.
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David Shen

toralf · Posted: Fri Aug 07, 2015 11:46 am Post subject:

And you didn't used an "Y" at a german keyboard - whilst a (assumed to be buggy) screen locker switched to US or <foo bar> layout while being in locked state?

davidshen84 · Guru Joined: 09 Aug 2008 Posts: 315

Well~ that is possible. But from the lock screen, I don't think I can switch keyboard layout. I always use US keyboard layout.
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David Shen

toralf · Posted: Fri Aug 07, 2015 5:58 pm Post subject:

Just curious - do you use sddm as login manager ?

asturm · Developer Joined: 05 Apr 2007 Posts: 9135

Try to re-emerge pam.

davidshen84 · Guru Joined: 09 Aug 2008 Posts: 315

toralf · Posted: Sat Aug 08, 2015 8:19 am Post subject:

davidshen84 · Guru Joined: 09 Aug 2008 Posts: 315

After a long time, i figured it out. It is because NetworkManager changed my hostname after it connected to my WIFI. And for some reason, the screen locker relies on my static hostname.

Any idea why NM changes my host name?
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David Shen

Fitzcarraldo · Posted: Sat Aug 08, 2015 7:18 pm Post subject:

You need to specify the hostname in the file /etc/NetworkManager/NetworkManager.conf. For example, the hostname of my laptop is clevow230ss so my NetworkManager.conf looks like the following:

kakarot · n00b Joined: 02 Feb 2004 Posts: 10

Although this thread is 2 years old, I have to add this for reference.
I migrated to an SSD EVO 250 using tar...
The new system is now on btrfs with subvolumes
The profile is 17 with plasma.
The migration went smoothly, login on sddm was ok but when plasma locks I couldn't login back.

The solution that worked was to re-emerge pam, as mentioned by asturm.
Thanks.

Fitzcarraldo · Posted: Thu Jan 04, 2018 1:37 pm Post subject:

Aquideon · n00b Joined: 12 Jan 2007 Posts: 4

For information and documentation:
I'm not sure what just happened, but my case is exactly the same as described above by "kakarot".
I just replaced my normal hard drive with an SSD Samsung 860 EVO and could log in after start, but not after "suspend to ram" and "hibernate".
After trying something around I could break down the problem to a simple scenario: Activate the screenlock. Could not login.

A simple "emerge --oneshot pam" did instantly the trick.

For reference:
- migration from HDD to SSD with rsync (on SysRescCD)
- login-manager SDDM 0.18.0

I don't really expect an answer, but there is something very strange going on.

asturm · Developer Joined: 05 Apr 2007 Posts: 9135

rsync did not copy xattr filecaps and `emerge -1 pam` restored that. Other things may be broken as well before rebuild.

Aquideon · n00b Joined: 12 Jan 2007 Posts: 4

Thanks for the explanation asturm. I completely wasn't aware of the xattrs.
As it seems, I missed a lot of stuff/changes with my well-running Gentoo over the last few years.

A comparison of the former and new root file systems revealed, that the xattrs were missing.
I've done the migration with 'rsync -ravHS' and without 'X', which should preserve extended attributes (at least the manpage claims this).

The hint that more things could be broken is very useful. Thank you!

Update/Edit: Just to be sure and avoid further problems I wiped the partition and did a new "rsync -ravHSAX". After reboot the login on a locked screen worked immediately.
Edit: Typo