I'm experiencing the same issue. Here is the output from /var/log/auth.log after attempting to login:
Jan 30 17:52:39 computername login[3483]: pam_unix(login:auth): conversation failed Jan 30 17:52:39 computername login[3483]: pam_unix(login:auth): auth could not identify password for [username] Jan 30 17:52:42 computername login[3483]: FAILED LOGIN (1) on '/dev/tty2' FOR 'UNKNOWN', Authentication failure Jan 30 17:52:42 computername login[3483]: pam_securetty(login:auth): cannot determine username Jan 30 17:52:46 computername login[3483]: FAILED LOGIN (2) on '/dev/tty2' FOR 'UNKNOWN', Error in service module Jan 30 17:52:46 computername login[3483]: pam_securetty(login:auth): cannot determine username Jan 30 17:52:49 computername login[3483]: FAILED LOGIN (3) on '/dev/tty2' FOR 'UNKNOWN', Error in service module -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to shadow in Ubuntu. https://bugs.launchpad.net/bugs/1812095 Title: console login loop after entering username followed by RETURN Status in shadow package in Ubuntu: Confirmed Bug description: <hostname> login: <user> password: Just do nothing. About two seconds later ... login: password: login: password: login: password: After this being displayed three times: "Too many failure" or so and login is restarting. You cant login at all. Only solution: clear the password for the account you want to login with. ProblemType: Bug DistroRelease: Ubuntu 18.10 Package: login 1:4.5-1ubuntu1 ProcVersionSignature: Ubuntu 4.18.0-14.15-generic 4.18.20 Uname: Linux 4.18.0-14-generic x86_64 ApportVersion: 2.20.10-0ubuntu13.1 Architecture: amd64 CurrentDesktop: XFCE Date: Wed Jan 16 19:34:30 2019 InstallationDate: Installed on 2011-10-19 (2645 days ago) InstallationMedia: Xubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012) SourcePackage: shadow UpgradeStatus: Upgraded to cosmic on 2018-11-03 (74 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/1812095/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
