In a vnc session, user can not input password at gnome login screen with ”Authentication error” messages

Solution Verified - Updated -

Environment

  • Red Hat Enterprise Linux 8.1
  • tigervnc-server-1.9.0-15.el8_1.x86_64

Issue

For the users who setup the vnc service follow the way provided by /usr/lib/systemd/user/vncserver@.service.
How to configure VNC Server in Red Hat Enterprise Linux 8?

  • In a vnc session, after Screen Lock occurred, user can not input password .
  • ”Authentication error” message shows up under the password input box.

login screen

Resolution

  • Bug#1827469 has been filed against this issue.

  • As a vnc user, ssh to the vnc server, do

$ vncserver -kill :<display No. of user session> 
$ vncserver :<the same display No. you just killed>

can somehow be a workaround. The issue won't show up again until the next OS reboot.

  • The procedure used on RHEL 7 also works on RHEL 8. It is another option for users to setup vnc server.
/usr/lib/systemd/system/vncserver@.service
# The vncserver service unit file
#
# Quick HowTo:
# 1. Copy this file to /etc/systemd/system/vncserver@.service
# 2. Replace <USER> with the actual user name and edit vncserver
#    parameters in the wrapper script located in /usr/bin/vncserver_wrapper
# 3. Run `systemctl daemon-reload`
# 4. Run `systemctl enable vncserver@:<display>.service`
#

Also see, How to configure VNC Server in Red Hat Enterprise Linux 7

Root Cause

  • From RHEL 8, a user systemd service file "/usr/lib/systemd/user/vncserver@.service" provides a way for non-root users to configure the vnc service. But Screen Lock triggers this login issue.
  • Component
  • vnc

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