Xorg receives SIGALRM and freezes during screen lock with Wine/GE-Proton application running - nvidia-driver-580-open, Ubuntu 24.04

Environment

Component Details
OS Ubuntu 24.04 LTS
Kernel 6.17.0-19-generic (#19~24.04.2-Ubuntu SMP PREEMPT_DYNAMIC)
GPU NVIDIA GeForce RTX 4070 Ti
Driver nvidia-driver-580-open 580.126.09
Session X11, GNOME Shell 46.2 / mutter 46.2
nvidia_drm modeset 1
NVreg_PreserveVideoMemoryAllocations 1

Application running at time of freeze:

  • Lutris (Flatpak) 0.5.22

  • Battle.net Launcher via GE-Proton10-34 / umu-launcher 1.4.0

  • DXVK enabled, WINEESYNC=1, WINEFSYNC=1


Behavior

Pressing Ctrl+L to lock the screen while Battle.net is running via Lutris/GE-Proton causes the display to freeze permanently. TTY remains accessible. systemctl restart gdm recovers the session.

Does not occur when Battle.net is closed before pressing Ctrl+L. 100% reproducible on demand.


What the logs show

1. DBus trace at moment of freeze dbus-monitor --session "interface='org.gnome.ScreenSaver'"

Lock request reached gnome-shell. No reply was ever returned. Log ends here.

method call sender=:1.60 -> destination=:1.74
    path=/org/gnome/ScreenSaver; member=Lock

method call sender=:1.74 -> destination=:1.33
    path=/org/gnome/ScreenSaver; member=Lock

2. strace on gnome-shell at moment of freeze strace -p <gnome-shell pid> -e trace=all -T -tt

gnome-shell blocked indefinitely on poll() on fd=10. Confirmed via ss as the X11 Unix socket connected to Xorg. gnome-shell sent a request to Xorg and Xorg never responded.

poll([{fd=10, events=POLLIN}], 1, -1

3. strace on Xorg at moment of freeze strace -p <xorg pid> -e trace=all -T -tt

Xorg was actively writing to client sockets and not blocked or hung when SIGALRM arrived from the kernel. After SIGALRM the process stopped responding entirely.

17:09:14.886203  writev(11, ...) = 32
17:09:14.886213  writev(11, ...) = 32
17:09:14.886222  writev(11, ...) = 32
17:09:14.900162  --- SIGALRM {si_signo=SIGALRM, si_code=SI_KERNEL} ---

4. Kernel log

Clean throughout. No GPU errors, no hung task warnings, no OOM events.