Comment 0 for bug 795324

Binary package hint: lightdm

On an Oneiric i386 system, I updated a number of packages yesterday (/var/log/dpkg.log attached compressed as dpkg.log.gz), and was given the choice between remaining with gdm (2.32.1-0ubuntu5) as my display manager, or switching to lightdm (0.3.7-0ubuntu1). I decided to try out lightdm. It appeared to work without problems, and defaulted to my default gdm session type as desired. But immediately after log in (to a unity-2d session), Apport informed me that lightdm had crashed with with SIGSEGV in g_child_watch_dispatch().

I don't have any more information, except that this bug looks similar to bug 795050, which is a SIGSEGV in a similar bug different dispatch function (g_main_context_dispatch()). But I did *not* also experience bug 795050. In that bug, Jean-Baptiste Lallement posted (https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/795050/comments/2) saying he got it at the same time as bug 795062, so perhaps this bug is actually a duplicate of (inaccessible to me, thus presumably private) bug 795062.

Since this crash was in a display manager, which provides a login screen, I am concerned about possible disclosure of sensitive information, so I'm keeping this bug private until it is processed by "Apport retracting service" or a bug triager (or I myself) examine it and determine that it's probably safe. However, I am manually subscribing Jean-Baptiste Lallement to this bug, so he can compare it to bug 795062.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: lightdm 0.3.7-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.39-3.10-generic 2.6.39
Uname: Linux 2.6.39-3-generic i686
Architecture: i386
Date: Wed Jun 8 19:14:16 2011
ExecutablePath: /usr/bin/lightdm
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha i386 (20110604)
ProcCmdline: lightdm
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
SegvAnalysis:
 Segfault happened at: 0x804bb73: mov 0x20(%eax),%eax
 PC (0x0804bb73) ok
 source "0x20(%eax)" (0xaaaaaaca) not located in a known VMA region (needed readable region)!
 destination "%eax" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: lightdm
StacktraceTop:
 ?? ()
 g_child_watch_dispatch (source=0x9c7fbc0, callback=0x804bb10, user_data=0x9c81000) at /build/buildd/glib2.0-2.29.4/./glib/gmain.c:4471
 g_main_dispatch (context=0x9c5b850) at /build/buildd/glib2.0-2.29.4/./glib/gmain.c:2477
 g_main_context_dispatch (context=0x9c5b850) at /build/buildd/glib2.0-2.29.4/./glib/gmain.c:3050
 g_main_context_iterate (context=0x9c5b850, block=1448320, dispatch=1, self=<value optimized out>) at /build/buildd/glib2.0-2.29.4/./glib/gmain.c:3128
Title: lightdm crashed with SIGSEGV in g_child_watch_dispatch()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: