Lock screen password incorrect

[nemeek]

When i lock the screen and type my password it say me: Password Incorrect

And my password not is incorrect, then i click in change user, in the gdm it work fine then.

[Richard Mitchell (mitchellrj)]

Confirmed on ubuntu-eee 8.04 on an Eee PC 1000h

I have an encrypted swap partition, could this be something to do with it?

[Richard Mitchell (mitchellrj)]

/var/logs/auth.log shows:

Dec 12 12:49:18 my-hostname unix_chkpwd[7693]: check pass; user unknown
Dec 12 12:49:18 my-hostname unix_chkpwd[7693]: password check failed for user (my-username)
Dec 12 12:49:18 my-hostname gnome-screensaver-dialog: pam_unix(gnome-screensaver:auth): authentication failure; logname= uid=1000 euid=1000 tty=:0.0 ruser= rhost= user=my-username

repeatedly. Unfortunately there is no entry for the successful authentication via gdm.

[Zarah Mattox (wawalak)]

I have the same issue on my EEE PC 1000. Found a similar bug: Bug #26175.

/var/logs/auth.log shows:
Dec 15 14:03:29 zarah-laptop unix_chkpwd[7282]: check pass; user unknown
Dec 15 14:03:29 zarah-laptop unix_chkpwd[7282]: password check failed for user (zarah)
Dec 15 14:03:29 zarah-laptop gnome-screensaver-dialog: pam_unix(gnome-screensaver:auth): authentication failure; logname= uid=1000 euid=1000 t$

# /var/log$ ls -l /etc/shadow
-rw-r----- 1 root shadow 966 2008-12-14 13:56 /etc/shadow

# uname -a
Linux mycomputer 2.6.24-21-eeepc #1 SMP Thu Aug 7 22:18:05 MDT 2008 i686 GNU/Linux

[Zarah Mattox (wawalak)]

Found a fix in the following thread and Ubuntu EEE question #45385

http://ubuntuforums.org/showthread.php?t=804647
https://answers.launchpad.net/ubuntu-eee/+question/45385

Fix is as follows (from iLoveRuby's post on the thread):
CAUSE:
/sbin/unix_chkpwd and /etc/shadow have wrong group/permissions

SOLUTION:
chown root:shadow /sbin/unix_chkpwd
chmod 2755 /sbin/unix_chkpwd
chown root:shadow /etc/shadow

[baseman_2007 (baseman-2001)]

This problem also exists when continuing after the standby mode.
The first time typing in the password tells you, your password is incorrect. The second time it works.

[glass.dimly (jmjohn)]

Tested Zarah's solution and it works.

Thank you!

[Launchpad Janitor (janitor)]

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

[NYR101 (nyr101-deactivatedaccount)]

I had this issue and can confirm it was resolved by:

chown root:shadow /sbin/unix_chkpwd
chmod 2755 /sbin/unix_chkpwd
chown root:shadow /etc/shadow
sudo chmod g+r /etc/shadow

Ubuntu version: 13.10
gnome-screensaver version: 3.6.1

Not sure if it makes a difference, but my /home/ is encrypted.