Same results for me. This is a security issue since it allows an unauthorized user with physical access to log into a sensitive account without a password.
In my case, the 2nd user is not guest, but another user with a password. I'm using gdm and gnome-shell session. Ubuntu 3.5.0-21.32-generic 3.5.7.1 gnome-screensaver 3.6.0-0ubuntu2 upgraded to quantal on 2013-01-10 (7 days ago) = from dmsg: = [177116.024201] gnome-shell[31699]: segfault at 18 ip 00007f63b1b32589 sp 00007fff9c944778 error 4 in libgio-2.0.so.0.3400.1[\ 7f63b1afd000+14e000] [180247.845478] gdm-session-wor[29009]: segfault at c4 ip 00007fa5c640a440 sp 00007fff47482e28 error 4 in libaccountsservice.\ so.0.0.0[7fa5c63f5000+3d000] [180277.554761] gnome-shell[27368]: segfault at 0 ip 00007fc894473589 sp 00007fffe496b318 error 4 in libgio-2.0.so.0.3400.1[7\ fc89443e000+14e000] = from syslog: = Jan 17 07:54:32 workstation gnome-session[29039]: CRITICAL: gsm_manager_set_phase: assertion `GSM_IS_MANAGER (manager)' faile\ d Jan 17 07:54:32 workstation gnome-session[29039]: Gtk-CRITICAL: gtk_main_quit: assertion `main_loops != NULL' failed Jan 17 07:54:32 workstation goa[29335]: goa-daemon version 3.6.0 exiting [main.c:154, main()] Jan 17 07:54:33 workstation acpid: client 1736[0:0] has disconnected Jan 17 07:54:33 workstation acpid: client 28910[0:0] has disconnected Jan 17 07:54:33 workstation acpid: client connected from 1736[0:0] Jan 17 07:54:33 workstation acpid: 1 client rule loaded Jan 17 07:54:33 workstation gdm-simple-slave[28907]: GLib-GIO-CRITICAL: g_dbus_connection_unregister_object: assertion `G_IS_\ DBUS_CONNECTION (connection)' failed Jan 17 07:54:33 workstation gdm-simple-slave[28907]: GLib-GIO-WARNING: (/build/buildd/glib2.0-2.34.1/./gio/gdbusinterfaceskel\ eton.c:739):remove_connection_locked: runtime check failed: (g_dbus_connection_unregister_object (data->connection, data->reg\ istration_id)) Jan 17 07:54:33 workstation gdm-simple-slave[28907]: GLib-GObject-CRITICAL: g_object_unref: assertion `G_IS_OBJECT (object)' \ failed Jan 17 07:54:33 workstation gdm-simple-slave[28907]: GLib-GObject-CRITICAL: g_object_ref: assertion `object->ref_count > 0' f\ ailed Jan 17 07:54:33 workstation gdm-simple-slave[28907]: GLib-GObject-CRITICAL: g_object_unref: assertion `object->ref_count > 0'\ failed Jan 17 07:54:33 workstation kernel: [180277.554761] gnome-shell[27368]: segfault at 0 ip 00007fc894473589 sp 00007fffe496b318\ error 4 in libgio-2.0.so.0.3400.1[7fc89443e000+14e000] Jan 17 07:54:33 workstation gnome-session[2959]: WARNING: Detected that screensaver has left the bus Jan 17 07:54:33 workstation gdm-password][2920]: GLib-GObject-CRITICAL: g_object_unref: assertion `G_IS_OBJECT (object)' fail\ ed Jan 17 07:54:33 workstation gnome-session[2959]: WARNING: Application 'gnome-shell.desktop' killed by signal 11 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gdm in Ubuntu. https://bugs.launchpad.net/bugs/1064584 Title: Locked gnome session unlocks without password authentication Status in “gdm” package in Ubuntu: Confirmed Bug description: When switching between users in ubuntu 12.10 using gdm a rather unpleasant behaviour can occur when a locked session unlocks without password authentication. Steps to reproduce: 1. Login as user1 (password required) 2. Lock screen 3. Select login as other user 4. Login in user2 which does not require any password, e.g. guest 5. Logout user2 6. Screen returns to unlocked session for user1 It doesn't happen every time but rather frequently so I suspect some sort of race involved. ProblemType: Bug DistroRelease: Ubuntu 12.10 Package: gdm 3.6.0-0ubuntu4 ProcVersionSignature: Ubuntu 3.5.0-17.27-generic 3.5.5 Uname: Linux 3.5.0-17-generic x86_64 ApportVersion: 2.6.1-0ubuntu1 Architecture: amd64 Date: Tue Oct 9 20:08:07 2012 InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012) SourcePackage: gdm UpgradeStatus: Upgraded to quantal on 2012-09-07 (32 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm/+bug/1064584/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
