mate-screensaver crashed with SIGSEGV in matemenu_tree_item_ref()

[Gene Soo]

unknown error after first boot MATE Desktop installed on Live Server 21.10 Daily Build.

ProblemType: Crash
DistroRelease: Ubuntu 21.10
Package: mate-screensaver 1.26.0-0ubuntu1
ProcVersionSignature: Ubuntu 5.13.0-14.14-generic 5.13.1
Uname: Linux 5.13.0-14-generic x86_64
ApportVersion: 2.20.11-0ubuntu68
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: MATE
Date: Sun Sep 12 03:03:13 2021
ExecutablePath: /usr/bin/mate-screensaver
InstallationDate: Installed on 2021-09-08 (3 days ago)
InstallationMedia: Ubuntu-Server 21.10 "Impish Indri" - Alpha amd64 (20210907)
ProcCmdline: /usr/bin/mate-screensaver --no-daemon
ProcEnviron:
 XDG_RUNTIME_DIR=<set>
 SHELL=/bin/bash
 LANGUAGE=en
 PATH=(custom, no user)
 LANG=en_US.UTF-8
SegvAnalysis:
 Segfault happened at: 0x7efca446db07 <matemenu_tree_item_ref+7>: lock addl $0x1,(%rdi)
 PC (0x7efca446db07) ok
 source "$0x1" ok
 destination "(%rdi)" (0x00000000) not located in a known VMA region (needed writable region)!
SegvReason: writing NULL VMA
Signal: 11
SourcePackage: mate-screensaver
StacktraceTop:
 matemenu_tree_item_ref () from /lib/x86_64-linux-gnu/libmate-menu.so.2
 gs_theme_manager_lookup_theme_info ()
 ?? ()
 ?? ()
 g_closure_invoke () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
Title: mate-screensaver crashed with SIGSEGV in matemenu_tree_item_ref()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lxd nopasswdlogin plugdev sudo
separator:

[Apport retracing service (apport)]

StacktraceTop:
 matemenu_tree_item_ref (itemp=0x0) at /build/mate-menus-8hX2K9/mate-menus-1.26.0/libmenu/matemenu-tree.c:1799
 matemenu_tree_get_root_directory (tree=<optimized out>) at /build/mate-menus-8hX2K9/mate-menus-1.26.0/libmenu/matemenu-tree.c:869
 find_info_for_id (id=0x555ec6ff3a90 "screensavers-footlogo-floaters.desktop", tree=<optimized out>) at ./src/gs-theme-manager.c:270
 gs_theme_manager_lookup_theme_info (theme_manager=0x7efc9400b080, name=name@entry=0x555ec6c9a4a0 "screensavers-footlogo-floaters") at ./src/gs-theme-manager.c:308
 manager_select_theme_for_job (manager=manager@entry=0x555ec6d15550, job=job@entry=0x555ec6f0e0a0) at ./src/gs-manager.c:257

[Apport retracing service (apport)]

StacktraceTop:
 matemenu_tree_item_ref (itemp=0x0) at /build/mate-menus-8hX2K9/mate-menus-1.26.0/libmenu/matemenu-tree.c:1799
 matemenu_tree_get_root_directory (tree=<optimized out>) at /build/mate-menus-8hX2K9/mate-menus-1.26.0/libmenu/matemenu-tree.c:869
 find_info_for_id (id=0x555ec6ff3a90 "screensavers-footlogo-floaters.desktop", tree=<optimized out>) at ./src/gs-theme-manager.c:270
 gs_theme_manager_lookup_theme_info (theme_manager=0x7efc9400b080, name=name@entry=0x555ec6c9a4a0 "screensavers-footlogo-floaters") at ./src/gs-theme-manager.c:308
 manager_select_theme_for_job (manager=0x555ec6d15550, job=0x555ec6f0e0a0) at ./src/gs-manager.c:257

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[John E Bowman (johnebowman)]

Dual monitors ViewSonic 22" monitors dimming for no reason that I can determine. have to reboot to clear problem.

[Lucy Llewellyn (lucyllewy)]

Unless I've done something wrong in my local build, I do not believe the patch fixes the problem :-(

Edit: though the patch I have been testing is to mate-screensaver, while the fix that Wimpy is working with appears to be related to mate-menus directly.

[Nicholas Guriev (mymedia)]

On Чт, 2021-12-09 at 20:38 +0000, John E Bowman wrote:
> Dual monitors ViewSonic 22" monitors dimming for no reason that I can
> determine. have to reboot to clear problem.
>

You can call to xrandr(1) to set monitors brightness back to one.
Something like:

   xrandr --output eDP-1 --brightness 1 --output DP-1 --brightness 1

[Ubuntu QA Website (ubuntuqa)]

This bug has been reported on the Ubuntu ISO testing tracker.

A list of all reports related to this bug can be found here:
http://iso.qa.ubuntu.com/qatracker/reports/bugs/1943369

[Launchpad Janitor (janitor)]

This bug was fixed in the package mate-menus - 1.26.0-1

---------------
mate-menus (1.26.0-1) unstable; urgency=medium

  [ Martin Wimpress ]
  * New upstream release.
  * debian/patches:
    + Add 1000_revert-matemenuntree.patch. (LP: #1943369)

  [ Mike Gabriel ]
  * debian/control:
    + Bump Standards-Version: to 4.6.0. No changes needed.
    + Drop transitional pkg 'gir1.2-mate-menu' and drop lintian override for
      it.
  * debian/watch:
    + Use format version 4.
  * debian/copyright:
    + Update copyright attributions.

 -- Mike Gabriel <email address hidden> Sat, 11 Dec 2021 18:50:40 +0100

[Martin Wimpress  (flexiondotorg)]

Fixed via mate-screensaver 1.26.1-1 uploaded to Jammy.

[Nicholas Guriev (mymedia)]

This bug should be considered as security critical. I've just run into the bug, the crash happened when screensaver was active and my laptop unlocked by itself. It'd be great to backport the fix to impish.

||/ Name Version Architecture Description
+++-================-===============-============-=================================
ii mate-screensaver 1.26.0-0ubuntu1 amd64 MATE screen saver and locker
ii libmate-menu2:amd64 1.26.0-0ubuntu1 amd64 implementation of the freedesktop menu specification for MATE (library)

dmesg output:

[ +5,223792] mate-screensave[44854]: segfault at 0 ip 00007ff03ff20b07 sp 00007ffce1a529a8 error 6 in libmate-menu.so.2.4.9[7ff03ff1d000+d000]
[ +0,000026] Code: da fe ff ff e8 8a d6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 89 f8 f0 83 07 01 c3 0f 1f 40 00 f3 0f 1e fa 48 89 f8 <f0> 83 07 01 c3 0f 1f 40 00 f3 0f 1e fa f0 83 2f 01 74 06 c3 0f 1f