Screensharing from my browser (Firefox snap) freezes the display requiring a hard reboot

[Oliver Smith]

In the firefox snap (although I'm not convinced it is specific to the firefox snap) when in a google meets session, I choose to share either my screen or a specific browser tab.

In ~40% of instances this results in a complete visual freeze of my system with no interactivity.

Audio / Microphone / Webcam /keyboard are still functional during this time. But I need to hard restart to be able to interact with my system again.

This happens more often the longer my system has been running and is pretty much guaranteed to happen once a day if I am presenting multiple times.

For reference I have two monitors: A UHD Monitor 1440p (60HZ) and a high refresh (144HZ) 1080p Monitor, both have scaling set to 100%. It does not seem to matter which screen I'm presenting to the other.

I have attached the journalctl of my previous boot.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: gnome-shell 42.5-0ubuntu1
ProcVersionSignature: Ubuntu 5.15.0-58.64-generic 5.15.74
Uname: Linux 5.15.0-58-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu82.3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Wed Jan 25 08:51:10 2023
DisplayManager: gdm3
InstallationDate: Installed on 2022-07-31 (177 days ago)
InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Release amd64 (20220419)
RelatedPackageVersions: mutter-common 42.5-0ubuntu1
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

Thanks for the bug report.

There doesn't seem to be anything freeze-related being written to the log so there are a few possibilities:

* The kernel froze (most likely in nvidia)
* gnome-shell or Xorg froze without crashing
* gnome-shell or Xorg did crash and there might be evidence in /var/crash

If you find no evidence in /var/crash then I would try either uninstalling the Nvidia driver or the card itself, or disabling the card in the BIOS. Just to see what it takes to avoid the freeze. Because I'm guessing if you boot with purely Intel graphics then the bug will stop happening (and not just because that will default to Wayland instead of Xorg).

[Daniel van Vugt (vanvugt)]

If you can ssh in then have a look to see if the Xorg and gnome-shell processes are still running during the freeze.

[Daniel van Vugt (vanvugt)]

If they are still running during the freeze then I would try:

  killall -ABRT gnome-shell

to force it to dump core and submit it as a crash report.

[Daniel van Vugt (vanvugt)]

When you ssh into the machine during a freeze, please also run 'top' to check if anything is spinning.