Public bug reported: Closing the laptop lid whilst a screen cast stream is live kills the whole GNOME session with SIGSEGV. Disabling a monitor clears its `current_mode`, and mutter's renderer passes that NULL straight into a function that dereferences it. I lost every open application. Reproduced twice locally so far, and appears to match some upstream reports,
- https://gitlab.gnome.org/GNOME/mutter/-/work_items/4708 - https://gitlab.gnome.org/GNOME/mutter/-/work_items/2718 I see in journal, 23:39:58 systemd-logind[2027]: Lid closed. 23:39:58 gnome-shell[95979]: meta_monitor_manager_get_logical_monitor_from_number: assertion '(unsigned int) number < g_list_length (manager->logical_monitors)' failed 23:39:58 gnome-shell[95979]: meta_workspace_get_work_area_for_monitor: assertion 'logical_monitor != NULL' failed 23:39:58 xdg-desktop-portal-gnome[96894]: Monitor 'Built-in display' has no configuration which is-current! 23:39:58 gnome-shell[95979]: GNOME Shell crashed with signal 11 23:40:07 org.gnome.Nautilus[470360]: Lost connection to Wayland compositor. 23:40:07 gvim[1562673]: Error reading events from display: Broken pipe 23:40:08 kernel: PM: suspend entry (s2idle) I manually symbolized a backtrace, #4 meta_monitor_mode_foreach_crtc (monitor=0x60a8883408f0, mode=0x0, func=0x71a8dcad0590 <collect_views>, user_data=0x7fff1179f9f0, error=0x0) at ../src/backends/meta-monitor.c:2698 #5 meta_renderer_real_get_views_for_monitor (monitor=0x60a8883408f0) at ../src/backends/meta-renderer.c:248 #6 meta_renderer_get_views_for_monitor (renderer=0x60a887c340a0) at ../src/backends/meta-renderer.c:260 #7 is_redraw_queued (source_monitor=0x60a893107180) at ../src/backends/meta-stream-source-monitor.c:278 #8 sync_cursor_state (source_monitor=0x60a893107180) at ../src/backends/meta-stream-source-monitor.c:297 #9 on_prepare_frame (source_monitor=0x60a893107180) at ../src/backends/meta-stream-source-monitor.c:332 #10 _clutter_marshal_VOID__OBJECT_BOXEDv () at clutter/clutter/clutter-marshal.c:1931 #14 clutter_stage_emit_prepare_frame () at ../clutter/clutter/clutter-stage.c:477 #15 handle_frame_clock_frame () at ../clutter/clutter/clutter-stage-view.c:1039 #16 clutter_frame_clock_dispatch () at ../clutter/clutter/clutter-frame-clock.c:1850 #17 frame_clock_source_dispatch () at ../clutter/clutter/clutter-frame-clock.c:1892 What I do not understand is why the stream source is still running its prepare-frame callback against a monitor that has just lost its mode. ProblemType: Crash DistroRelease: Ubuntu 26.10 Package: gnome-shell 51~beta-0ubuntu1 ProcVersionSignature: Ubuntu 7.2.0-5.5-generic 7.2.0 Uname: Linux 7.2.0-5-generic x86_64 NonfreeKernelModules: zfs ApportVersion: 2.36.0-0ubuntu1 Architecture: amd64 CasperMD5CheckResult: pass CrashCounter: 1 CurrentDesktop: ubuntu:GNOME Date: Tue Sep 8 23:39:59 2026 DisplayManager: gdm3 ExecutablePath: /usr/bin/gnome-shell ExecutableTimestamp: 1787261668 InstallationDate: Installed on 2026-04-14 (147 days ago) InstallationMedia: Ubuntu 24.04.4 LTS "Noble Numbat" - Release amd64 (20260210) ProcCmdline: /usr/bin/gnome-shell --mode=ubuntu ProcCwd: /home/charles Signal: 11 SignalName: SIGSEGV SourcePackage: gnome-shell StacktraceTop: __pthread_kill_implementation (threadid=<optimized out>, signo=11, no_tid=0) at ./nptl/pthread_kill.c:44 __pthread_kill_internal (threadid=<optimized out>, signo=11) at ./nptl/pthread_kill.c:89 __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=11) at ./nptl/pthread_kill.c:100 __GI_raise (sig=11) at ../sysdeps/posix/raise.c:26 ??? () Title: gnome-shell crashed with SIGSEGV in meta_monitor_mode_foreach_crtc() from meta_renderer_real_get_views_for_monitor() when closing the lid during a screen cast UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip libvirt lpadmin lxd plugdev sbuild sudo users separator: ** Affects: gnome-shell (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-crash stonking third-party-packages wayland-session -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2166855 Title: gnome-shell crashed with SIGSEGV in meta_monitor_mode_foreach_crtc() from meta_renderer_real_get_views_for_monitor() when closing the lid during a screen cast To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/2166855/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
