gdm-session-worker crashed with SIGSEGV in act_user_is_loaded()

[Irwin]

don't know

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: gdm 3.0.4-0ubuntu4
ProcVersionSignature: Ubuntu 3.0-3.4-generic 3.0.0-rc5
Uname: Linux 3.0-3-generic x86_64
Architecture: amd64
Date: Sat Jul 9 16:27:48 2011
ExecutablePath: /usr/lib/gdm/gdm-session-worker
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110705.1)
ProcCmdline: /usr/lib/gdm/gdm-session-worker
ProcEnviron:
 LANG=en_US.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
SegvAnalysis:
 Segfault happened at: 0x7f9fd2d27530 <act_user_is_loaded>: movzbl 0xac(%rdi),%eax
 PC (0x7f9fd2d27530) ok
 source "0xac(%rdi)" (0x000000ac) not located in a known VMA region (needed readable region)!
 destination "%eax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: gdm
StacktraceTop:
 act_user_is_loaded () from /usr/lib/libaccountsservice.so.0
 ?? ()
 ?? ()
 ?? ()
 pam_vprompt () from /lib/x86_64-linux-gnu/libpam.so.0
Title: gdm-session-worker crashed with SIGSEGV in act_user_is_loaded()
UpgradeStatus: Upgraded to oneiric on 2011-07-09 (0 days ago)
UserGroups:

[Apport retracing service (apport)]

StacktraceTop:
 act_user_is_loaded (user=0x0) at act-user.c:1195
 gdm_session_settings_load (settings=0x19ee8a0, username=0x1a0e920 "") at gdm-session-settings.c:358
 attempt_to_load_user_settings (worker=0x19f7020) at gdm-session-worker.c:600
 gdm_session_worker_update_username (worker=0x19f7020) at gdm-session-worker.c:642
 gdm_session_worker_process_pam_message (number_of_messages=1, messages=0x7fff898d4808, responses=0x7fff898d4800, worker=0x19f7020) at gdm-session-worker.c:795