I've already provided the requested crash information directly on the bug report via the Launchpad web form (see my comment above), including:
- The retraced backtrace with debug symbols (libmutter-18-0-dbgsym 50.1-0ubuntu2.2), showing the identical crash location to the original report (meta_kms_impl_get_kms / meta_kms_impl_device_get_fd). - journalctl output covering both crash sessions (Sept 4 and Sept 6), redacted of identifying details (hostname, MAC/IP addresses, disk/network-connection UUIDs, NextDNS account ID). Regarding the two automated steps in this notification: 1. ubuntu-bug on the .crash file: I attempted this, but apport-gtk crashed/failed silently when processing the file (large gnome-shell coredump, ~63MB). I worked around this by extracting the backtrace manually via gdb and posting it directly as a comment instead. 2. errors.ubuntu.com/user/<whoopsie-id>: this endpoint currently returns HTTP 500 (Internal Server Error) for my whoopsie-id. I confirmed this is server-side, not a local network/DNS issue: $ curl -sI https://errors.ubuntu.com/ HTTP/2 200 $ curl -sI https://errors.ubuntu.com/user/<my-whoopsie-id> HTTP/2 500 The main errors.ubuntu.com page loads fine, only the per-user page fails. Let me know if any additional data would be helpful. poniedziałek, 7 września 2026 04:05, Daniel van Vugt <[email protected]> napisał(a): > To help us find the correct crash bucket, please follow these steps: > > 1. Look in /var/crash for crash files and if found run: > ubuntu-bug YOURFILE.crash > Then tell us the ID of the newly-created bug. > > 2. If step 1 failed then look at https://errors.ubuntu.com/user/ID where > ID is the content of file /var/lib/whoopsie/whoopsie-id on the machine. > Do you find any links to recent problems on that page? If so then please > send the links to us. > > Please take care to avoid attaching .crash files to bugs as we are > unable to process them as file attachments. It would also be a security > risk for yourself. > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/2165888 > > Title: > gnome-shell 50.1 SIGSEGV in KMS thread during mode set on display wake > after privacy screen toggle (regression of bug 2085420) > > Status in mutter package in Ubuntu: > Incomplete > > Bug description: > gnome-shell 50.1 SIGSEGV in KMS thread during mode set on display wake > after privacy screen toggle (regression of bug 2085420) > > gnome-shell crashes with SIGSEGV in mutter's KMS thread when the > built-in panel is re-enabled after idle blanking, if the hardware > privacy screen was toggled earlier in the session. The crash is in the > atomic mode-set path: meta_kms_mode_create_blob_id() calls > meta_kms_impl_device_get_fd() with an invalid MetaKmsImplDevice > pointer. > > This is the trigger condition of bug 2085420, closed via bug 2085423 > with the fix landing upstream in mutter 49.rc (merge request > mutter!4742). The fix is present in 50.1, so this is a regression or a > new bug with the same trigger. > > Environment: > - libmutter-18-0 50.1-0ubuntu2.2, gnome-shell 50.1-0ubuntu1.2, Ubuntu 26.04 > - Wayland session, native backend, i915, atomic mode setting > - Linux 7.0.0-30-generic > - Lenovo ThinkPad T14 Gen 1 (20S00078MX), PrivacyGuard panel, DRM privacy > screen provider privacy_screen-thinkpad_acpi > > Steps to reproduce: > 1. Fresh boot, Wayland session. Blank the screen on idle and wake it — > survives, repeatedly (verified with several cycles at a 60 s blank delay). > 2. Toggle the privacy screen with Fn+D: on, then off (sw_state and hw_state > back to Disabled). > 3. Let the screen blank, wake with any input. > > gnome-shell segfaults during the wake mode set and the session is > lost. Reproduced 4 times over two days, the last with exactly this > protocol. No suspend/resume involved, no monitor hotplug. > > Backtrace from the apport core dump, retraced with > libmutter-18-0-dbgsym 50.1-0ubuntu2.2. Crashing thread is the KMS > thread processing META_KMS_UPDATE_FLAG_MODE_SET: > > #6 meta_kms_impl_get_kms (impl=<error reading variable: Cannot access > memory at address 0x638bea15a607>) at > ../src/backends/native/meta-kms-impl.c:52 > #7 meta_kms_impl_device_get_fd (impl_device=0x638bea15a6af) at > ../src/backends/native/meta-kms-impl-device.c:1235 > #8 meta_kms_mode_create_blob_id (mode=0x7dc4c401fc50, > error=0x7dc4d91fe118) at ../src/backends/native/meta-kms-mode.c:51 > #9 process_mode_set (...) at > ../src/backends/native/meta-kms-impl-device-atomic.c:409 > #10 process_entries (...) at > ../src/backends/native/meta-kms-impl-device-atomic.c:978 > #11 meta_kms_impl_device_atomic_process_update (impl_device=0x7dc4c40052c0, > ...) at ../src/backends/native/meta-kms-impl-device-atomic.c:1204 > #12 do_process (impl_device=0x7dc4c40052c0, ..., > flags=META_KMS_UPDATE_FLAG_MODE_SET) at > ../src/backends/native/meta-kms-impl-device.c:1649 > #13 process_mode_set_update (...) at > ../src/backends/native/meta-kms-impl-device.c:2330 > #14 meta_kms_impl_device_process_update (...) at > ../src/backends/native/meta-kms-impl-device.c:2370 > #15 process_sync_update_in_impl (...) at > ../src/backends/native/meta-kms-device.c:304 > #16 meta_thread_impl_dispatch (...) at > ../src/backends/native/meta-thread-impl.c:543 > #17 impl_source_dispatch (...) at > ../src/backends/native/meta-thread-impl.c:177 > > The impl_device argument in frame #7 (0x638bea15a6af) is unreadable > and misaligned, while the impl_device in frames #10-#14 > (0x7dc4c40052c0) is valid — the MetaKmsMode in frame #8 appears to > hold a dangling pointer to a freed or stale MetaKmsImplDevice. > > Journal at crash: > > Aug 31 08:29:23 gnome-shell[24522]: Launching DING process > Aug 31 08:29:23 gnome-shell[24522]: GNOME Shell crashed with signal 11 > > To manage notifications about this bug go to: > https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2165888/+subscriptions > > > -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2165888 Title: gnome-shell 50.1 SIGSEGV in KMS thread during mode set on display wake after privacy screen toggle (regression of bug 2085420) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2165888/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
