[Bug 2152124] Re: Sudden loss of session (back to login/initramfs screen)

Hi Daniel, I have a critical update regarding the i915 Wayland crashes. I have managed to find a 100% reproducible trigger for the hard lockup, and I also discovered a severe UX bug in Plymouth that occurs immediately after this crash. Environment: Hardware: ASUS Zenbook UX331UA (Intel graphics) OS/Kernels tested: Ubuntu 26.04, kernels 7.0.0-15-generic and the latest 7.0.0-22-generic Session: Wayland Bug 1: Reproducible Hard Lockup (GTK / Wayland / i915 regression) The regression is still fully present in the new 7.0.0-22 kernel. The system suffers a hard lockup exactly at the moment specific GTK applications trigger a UI change (such as opening a save dialog or rendering a download completion notification). 100% Reproducible triggers: Firefox: Downloading and saving a PDF file. The system locks up the exact moment the download finishes and the UI attempts to update. Remmina: Exporting to PDF. Thunderbird: Launching the app (happened frequently, though might be partially mitigated in recent TB updates). The Crucial Clue: Google Chrome works perfectly and never crashes. It can download files and run for hours without issues. This strongly suggests the bug is strictly tied to how native GTK interacts with Wayland and the i915 driver. Chrome's Aura/Ozone engine bypasses the faulty calls entirely. Bug 2: LUKS / Plymouth Alt key trapping after the crash After the system hard-reboots from the crash mentioned above, the LUKS decryption screen (Plymouth) behaves erratically regarding keyboard input. The Right Alt (AltGr) key is intercepted by Plymouth and acts as a display switch. Pressing Right Alt + X or Right Alt + 3 (which is required to type the # character on a CZ keyboard layout) does not output the character into the password field. Instead, it forcefully switches Plymouth to the raw text tty console (and back to GUI on the next press). Result: It becomes physically impossible to unlock the encrypted drive if the password contains characters requiring the AltGr modifier. The only workaround is to forcefully power off the machine and do a cold boot, after which Plymouth behaves normally and accepts the # character. Let me know if you need any specific logs, though the hard lockup happens so fast that journalctl usually doesn't have time to flush the exact crash trace to the disk. -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2152124 Title: Sudden loss of session (back to login/initramfs screen) Status in linux package in Ubuntu: New Bug description: When using Thunderbird under Wayland on Ubuntu 26.04 (Intel GPU, ASUS Zenbook UX310UA), pressing the Up/Down arrow keys to scroll through emails causes an immediate and hard crash of the GNOME Shell / Wayland compositor. The system drops connection to xwayland and crashes back to the disk decryption/login screen. The issue is 100% reproducible on Wayland. Workaround: Switching the session to "Ubuntu on Xorg" completely resolves the issue and Thunderbird works normally. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: gnome-shell 50.1-0ubuntu1 ProcVersionSignature: Ubuntu 7.0.0-15.15-generic 7.0.0 Uname: Linux 7.0.0-15-generic x86_64 ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Sun May 10 13:32:06 2026 DisplayManager: gdm3 InstallationDate: Installed on 2025-05-25 (350 days ago) InstallationMedia: Ubuntu 25.04 "Plucky Puffin" - Release amd64 (20250415.3) ProcEnviron: LANG=cs_CZ.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> RelatedPackageVersions: mutter-common 50.1-0ubuntu2 SourcePackage: gnome-shell UpgradeStatus: Upgraded to resolute on 2026-05-10 (0 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2152124/+subscriptions