unity-greeter crashed with SIGSEGV in g_object_unref()

[Andreas Schultz]

graphical login not working at all

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: unity-greeter 0.0.5-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-9.14-generic 3.0.3
Uname: Linux 3.0.0-9-generic x86_64
Architecture: amd64
Date: Thu Aug 25 14:10:24 2011
ExecutablePath: /usr/sbin/unity-greeter
ProcCmdline: /usr/sbin/unity-greeter
ProcEnviron:
 LANG=en_GB.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/false
SegvAnalysis:
 Segfault happened at: 0x7f606badae80: mov (%rdi),%rax
 PC (0x7f606badae80) ok
 source "(%rdi)" (0x00000000) not located in a known VMA region (needed readable region)!
 destination "%rax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity-greeter
StacktraceTop:
 ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
 ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
 g_object_unref () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
 ?? ()
 ?? ()
Title: unity-greeter crashed with SIGSEGV in g_object_unref()
UpgradeStatus: Upgraded to oneiric on 2011-07-05 (52 days ago)
UserGroups:

[Apport retracing service (apport)]

StacktraceTop:
 g_settings_backend_unsubscribe (backend=0x0, name=0x0) at /build/buildd/glib2.0-2.29.16/./gio/gsettingsbackend.c:863
 g_settings_finalize (object=0x14b0630) at /build/buildd/glib2.0-2.29.16/./gio/gsettings.c:555
 g_object_unref (_object=0x14b0630) at /build/buildd/glib2.0-2.29.16/./gobject/gobject.c:2746
 settings_daemon_configure (self=<optimized out>) at settings-daemon.c:209
 settings_daemon_start_co (_data_=0x14bde90) at settings-daemon.c:149

[Robert Ancell (robert-ancell)]

Michael, hoping you can shed some light on this. I can't see anything obviously wrong with the code in settings-daemon.vala.

[Michael Terry (mterry)]

I don't see anything obviously wrong either. But the stack trace given is memory-corrupted:
 * The line it points to in the source is just a g_strdup.
 * The memory passed to g_object_unref is the __tmp6__ pointer, which is just a string.
 * cairo_pattern_create_rgb is high up in the stack (which then apparently calls __libc_start_main...)

So it may not be a bug in settings-daemon.vala itself.

[Puppu Tuppu (puppu-tuppu)]

I don't understand how this is medium. It stops my system from booting and I don't know how to turn lightdm off! (and if I boot straight to command line and start x from there, sound isn't working etc.)

[Robert Ancell (robert-ancell)]

I'm closing this fix released as all the duplicates are on version 0.0.5 and it hasn't been reported since. Please open a new bug if this occurs again.

[Puppu Tuppu (puppu-tuppu)]

Reopen the bug, my computer still is not working at all, I get an infinite crash loop upon boot.

Please change Importance to High.

[Puppu Tuppu (puppu-tuppu)]

Is there some debugging packages I can install to provide you with further data.

[Andreas Schultz (aschultz)]

got a new chrash with 0.0.8, submitted as #850937

[Dmitry Shachnev (mitya57)]

Reopening per comments 9 and 11.

@Puppu: you may want to use lightdm-greeter-gtk for now. Install this package and change "greeter-session=unity-greeter" to "greeter-session=lightdm-greeter-gtk" in /etc/lightdm/lightdm.conf.

@Robert: it has the same stacktrace, so it's not a new bug but this one.

[Dmitry Shachnev (mitya57)]

Well, OK, bug 850937 may be more useful. Keeping as is.

[Ricardo Bánffy (rbanffy)]

Just did a dist-upgrade and the problem re-ocuurred. :-/