Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Bug 1998356

Summary: Screen Locking Failure "Lock was blocked by application"
Product: Red Hat Enterprise Linux 8 Reporter: Brandon Clark <brclark>
Component: gnome-shellAssignee: Florian Müllner <fmuellner>
Status: CLOSED CANTFIX QA Contact: Desktop QE <desktop-qa-list>
Severity: high Docs Contact:
Priority: medium    
Version: 8.4CC: alanm, amike, brclark, casantos, jadahl, jwright, mbliss, mkolbas, sbarcomb
Target Milestone: rcFlags: pm-rhel: mirror+
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2022-02-15 14:02:35 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Brandon Clark 2021-08-26 22:17:20 UTC
Description of problem:
When attempting to lock screen, the following error is observed:
	“Lock was blocked by an application”

The line outputted by the messages log is the following:

	gnome-shell[22519]: pushModal: invocation of begin_modal failed
	gnome-shell[22519]: pushModal: invocation of begin_modal failed
	gnome-shell[22519]: error :Unable to lock: Lock was blocked by an application

Certain applications such as firefox an gnome-terminal are two applications that were observed by the customer this was opened for that could cause this behavior. It appears that the screen lock signal is even ignored wholesale in certain cases as it is not registered in dbus diagnostic output.

Version-Release number of selected component (if applicable):
gdm-3.28.3.39.el8.x86_64
libXi-1.7.10-1.el8.x86_64
gnome-shell-3.32.2-30.el8.x86_64
dbus-1.12.8-12.el8_4.2.x86_64


How reproducible:
Consistent

Steps to Reproduce:
	1)Install system via a kickstart with STIG implemented, though with FIPS disabled. Ensure 'use_nfs_home_dir is set to "on"'.
	2) Login
	3) Attempt to induce issue by idle or <Super>l combination while programs such as firefox or gnome-terminal are open.

Actual results:
	Error output 

Expected results:
	Screen locks successfully.

Additional info:
	I was unable to reproduce this behavior myself after considerable testing. This issue is evident in RHEL 7 as well, though customer confirmed they observed it in 8.

Comment 1 Florian Müllner 2021-08-27 11:29:13 UTC
The most likely reason is what the warning message says: An application has grabbed the keyboard or pointer (most probably because of an open (popup) menu).

Not locking the screen is the best we can do in that situation. The alternative leaves the user without a way to unlock the session in the best case, and sends the password to the application that holds the grab in the worst case.

So unless there's an indication that the failure is not triggered by an existing grab, this is WONTFIX/CANTFIX.

Comment 2 Steve Barcomb 2022-02-15 14:02:35 UTC
Marking this bug closed since we have not heard back for sometime and the customer case is closed.  If there is renewed interest in this bug please reach out to me directly.

-Steve