gdm-simple-chooser crashed with SIGSEGV in _XInternAtom() from assistive_registry_start() from load_a11y()

[orondo jones]

https://errors.ubuntu.com/problem/12f1d97cf7a8838894fd1cb2487acfdda0fb2bad

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NOTE: I didn't get a new bug ID after running ubuntu-bug. I did get a web link which is what I used to submit this bug.

(1) lsb_release-rd output
==============================
Description: Ubuntu 18.04 LTS
Release: 18.04

(2) apt-cache-policy output
==============================gdm3:
  Installed: 3.28.0-0ubuntu1
  Candidate: 3.28.0-0ubuntu1
  Version table:
 *** 3.28.0-0ubuntu1 500
        500 http://us.archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status

(3) I expected to be able login using X

(4) What happened:
Looking in syslog, I see the following message:
May 22 16:47:33 Paradise kernel: [ 5793.249149] gdm-simple-choo[25864]: segfault at 1 ip 00007fb0267de4b9 sp 00007fff46d5e0d0 error 6 in libX11.so.6.3.0[7fb0267b6000+134000]

ProblemType: Crash
DistroRelease: Ubuntu 18.04
Package: gdm3 3.28.0-0ubuntu1
ProcVersionSignature: Ubuntu 4.15.0-22.24-generic 4.15.17
Uname: Linux 4.15.0-22-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: GNOME-Greeter:GNOME
Date: Thu May 24 08:01:56 2018
ExecutablePath: /usr/lib/gdm3/gdm-simple-chooser
ProcCmdline: /usr/lib/gdm3/gdm-simple-chooser
ProcEnviron:
 SHELL=/bin/false
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 XDG_RUNTIME_DIR=<set>
SegvAnalysis:
 Segfault happened at: 0x7fd36a0c314e <_XInternAtom+558>: mov %rdx,(%rax)
 PC (0x7fd36a0c314e) ok
 source "%rdx" ok
 destination "(%rax)" (0x00000001) not located in a known VMA region (needed writable region)!
SegvReason: writing NULL VMA
Signal: 11
SourcePackage: gdm3
StacktraceTop:
 _XInternAtom (dpy=dpy@entry=0x55b606b768e0, name=name@entry=0x55b604f8611b "AT_SPI_IOR", onlyIfExists=onlyIfExists@entry=0, psig=psig@entry=0x7ffdb56073b8, pidx=pidx@entry=0x7ffdb56073b0, pn=pn@entry=0x7ffdb56073b4) at IntAtom.c:76
 XInternAtom (dpy=0x55b606b768e0, name=0x55b604f8611b "AT_SPI_IOR", onlyIfExists=0) at IntAtom.c:175
 ()
 __libc_start_main (main=0x55b604f81d30, argc=1, argv=0x7ffdb5607578, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffdb5607568) at ../csu/libc-start.c:310
 ()
Title: gdm-simple-chooser crashed with SIGSEGV in _XInternAtom()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

mtime.conffile..etc.gdm3.custom.conf: 2018-05-22T15:03:52.418178

[Apport retracing service (apport)]

StacktraceTop:
 XRebindKeysym (dpy=0x55b604f8611b, keysym=140727646450748, mlist=0x21104f00, nm=0, str=0x7ffdb56073b4 "", nbytes=112683232) at ../../src/KeyBind.c:930
 ?? ()
 ?? ()
 ?? ()
 ?? ()

[Launchpad Janitor (janitor)]

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

[Daniel van Vugt (vanvugt)]

Also tracking in:
https://errors.ubuntu.com/problem/12f1d97cf7a8838894fd1cb2487acfdda0fb2bad

[orondo jones (ojones)]

I was looking through the crash results and saw that libX11.6.3.so seemed to be modified. I used apt-get remove libX11-dev and then re-installed it. I still get a crash ; however, libX11.6.3.so no longer shows a modified status (using version provided by ubuntu). Please review the attached log file.