SUMMARY I have an openconnect VPN I use to connect to work. This involves using SAML credentials to supply a cookie for authentication. These credentials are entered in an SSO webview. Since the most recent Plasma update, it no longer renders, instead creating a hall of mirrors effect until kded6 eventually crashes with a segfault. See attached files. STEPS TO REPRODUCE 1. Click "connect" on plasma-nm VPN connection 2. Click "Login" to open the SSO embedded webview OBSERVED RESULT You get a hall of mirrors effect and kded6 crashes EXPECTED RESULT The SSO embedded webview renders properly SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 6.3.4 KDE Frameworks Version: 6.12.0 Qt Version: 6.9.0 Kernel Version: 6.14.1-arch1-1 (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 7 7800X3D 8-Core Processor Memory: 61.9 GiB of RAM Graphics Processor 1: AMD Radeon RX 6600 XT Graphics Processor 2: AMD Radeon Graphics Manufacturer: ASUS ADDITIONAL INFORMATION I labelled this under "generic-crash" because I'm not sure which component is at fault - feel free to move it. I thought this may have been due to a webkit2gtk4 update, but rolling that back doesn't resolve the issue. I thought it might be openconnect itself, but that hasn't had an update since december last year. This first started when Tuesday's KDE/QT/Plasma packages were updated (the release on the 2nd of April). I can confirm that rolling back everything to April 1st resolves the issue: https://wiki.archlinux.org/title/Arch_Linux_Archive#How_to_restore_all_packages_to_a_specific_date
Created attachment 180139 [details] Video of reproduction I had to end the recording short, else once kded6 segfaults I can't figure out how to stop the recording.
Created attachment 180140 [details] coredumpctl info output
Created attachment 180141 [details] backtrace log
Created attachment 180142 [details] journal output encompasing the reproduction
The coredump is too large to attach. You can download it from my s3 here https://s4.maybe.sh/public/core.kded6.1000.604777578f4d4276b94cfb3524ff9b08.1475.1744256644000000.zst
This is unfortunately a bug in Qt 6.9 that affects hardware acceleration of Qt web views when using an AMD GPU; see https://bugreports.qt.io/browse/QTBUG-135786. You may be able to work around it by setting QTWEBENGINE_CHROMIUM_FLAGS="--disable-gpu --disable-gpu-compositing" in /etc/environment and rebooting.
Thanks Nate, I'll give the workaround a try and CC myself on the upstream bug so I know when to disable the workaround.
Followup: I can confirm that the workaround works
*** Bug 504218 has been marked as a duplicate of this bug. ***