This happens when you try to switch users. Switching to terminal and restarting the lightdm service results in a lock-screen of the first user, from which you can log back in.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to lightdm in Ubuntu. https://bugs.launchpad.net/bugs/833925 Title: lightdm crashed with SIGSEGV in initialize_password_db() Status in “lightdm” package in Ubuntu: Confirmed Bug description: LightDM took a long time to verify my password and after that this bug report appeared. jose@JARR-Laptop:~$ lsb_release -rd Description: Ubuntu oneiric (development branch) Release: 11.10 jose@JARR-Laptop:~$ apt-cache policy lightdm lightdm: Installed: 0.9.3-0ubuntu7 Candidate: 0.9.3-0ubuntu7 Version table: *** 0.9.3-0ubuntu7 0 500 http://archive.ubuntu.com/ubuntu/ oneiric/main amd64 Packages 100 /var/lib/dpkg/status ProblemType: Crash DistroRelease: Ubuntu 11.10 Package: lightdm 0.9.3-0ubuntu7 ProcVersionSignature: Ubuntu 3.0.0-9.14-generic 3.0.3 Uname: Linux 3.0.0-9-generic x86_64 NonfreeKernelModules: wl Architecture: amd64 Date: Thu Aug 25 17:42:30 2011 Disassembly: => 0x0: Cannot access memory at address 0x0 ExecutablePath: /usr/sbin/lightdm InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110803.1) ProcCmdline: lightdm ProcEnviron: PATH=(custom, no user) SegvAnalysis: Segfault happened at: 0x0: Cannot access memory at address 0x0 PC (0x00000000) not located in a known VMA region (needed executable region)! Stack memory exhausted (SP below stack segment) SegvReason: executing NULL VMA Signal: 11 SourcePackage: lightdm StacktraceTop: ?? () ?? () from /lib/security/pam_smbpass.so initialize_password_db () from /lib/security/pam_smbpass.so pam_sm_authenticate () from /lib/security/pam_smbpass.so ?? () from /lib/x86_64-linux-gnu/libpam.so.0 Title: lightdm crashed with SIGSEGV in initialize_password_db() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/833925/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
