Bug 2392454

Summary:	Kwin crashes when unplugging a usb-c monitor
Product:	[Fedora] Fedora	Reporter:	marcdeop
Component:	kwin	Assignee:	marcdeop
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	rawhide	CC:	jgrulich, kde-sig, marcdeop, suraj.ghimire7, than
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kwin-6.4.4-4.fc42 kwin-6.4.4-5.fc43	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2025-09-02 01:47:39 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2324224

Description marcdeop 2025-09-01 21:01:48 UTC

This is just a downstream bug from https://bugs.kde.org/show_bug.cgi?id=509004

A fix has already been issued here: https://src.fedoraproject.org/rpms/kwin/c/7525f9657c8b6fdd425cfd8dd9b7f04713164a24?branch=rawhide

Reproducible: Always

Steps to Reproduce:
(copy&paste from upstream bug)

Lenovo T14s Gen 2 laptop. I have two similar monitor setups at home & work. Both are 2x 2560x1440 monitors connected via USB-C -> left monitor -> MST/DP Out -> right monitor. The crash is reproducible in both setups.

Every time I unplug the USB-C cable to the external monitors, after a few seconds kwin_wayland crashes, taking most of the desktop applications with it (Firefox, Thunderbird, VSCode). The only windows that survive the crash are Konsole, Dolphin & LibreOffice (I'm using the kf6 integration for it).

The problem started after I upgraded to Plasma 6.4.4.

I have already verified that it is not related to the kernel 6.15.x -> 6.16.x upgrade in Fedora. The crash also happens under 6.15.x, where Plasma & external monitor setup was working fine before the upgrade to 6.4.4.

I have another laptop at home that is connected via HDMI & AVR to a TV. I have not observed the crash in that setup.

The crash can be reproduced every time.
Actual Results:
Kwin crash

Expected Results:
No crash :-)

Comment 1 Fedora Update System 2025-09-01 21:03:03 UTC

FEDORA-2025-9e6e523ee6 (kwin-6.4.4-4.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2025-9e6e523ee6

Comment 2 Fedora Blocker Bugs Application 2025-09-01 21:06:03 UTC

Proposed as a Freeze Exception for 43-beta by Fedora user marcdeop using the blocker tracking app because:

 A kwin bug causes a severe crash on a fairly common situation: unplug a monitor from the system.

I request an update to be allowed to proceed :-)

Comment 3 Fedora Update System 2025-09-01 21:07:26 UTC

FEDORA-2025-8d8664913d (kwin-6.4.4-4.fc42) has been submitted as an update to Fedora 42.
https://bodhi.fedoraproject.org/updates/FEDORA-2025-8d8664913d

Comment 4 Fedora Update System 2025-09-02 01:14:26 UTC

FEDORA-2025-9e6e523ee6 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2025-9e6e523ee6`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2025-9e6e523ee6

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 5 Fedora Update System 2025-09-02 01:47:39 UTC

FEDORA-2025-8d8664913d (kwin-6.4.4-4.fc42) has been pushed to the Fedora 42 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 6 Fedora Update System 2025-09-16 00:19:32 UTC

FEDORA-2025-cca3b373bd (calibre-8.7.0-5.fc43, dtk6core-6.0.27-7.fc43, and 55 more) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.