RHBA-2011:1721 - Bug Fix Advisory

Topic

Updated gdm packages that fix multiple bugs are now available for Red Hat
Enterprise Linux 6.

Description

The GNOME Display Manager (GDM) provides the graphical login screen, shown
shortly after boot up, log out, and when user-switching.

This update fixes these bugs:

• GDM did not properly queue up multiple authentication messages so that

messages could quickly be overwritten by newer messages. The queueing mechanism
has been modified, and this problem no longer occurs. (BZ#661618)

• If a Russian keyboard layout was chosen during system installation, the login

screen was configured to use Russian input for user names and passwords by
default. However, GDM did not provide any visible way to switch between keyboard
layouts, and pressing Left Shift and Right Shift keys did not cause the input to
change to ASCII mode in GDM. Consequently, users were not able to log in to the
system. With this update, GDM allows users to switch keyboard layout properly
using the keyboard layout indicator, and users can now log in as expected.
(BZ#628462)

• GDM did not properly release file descriptors used with XDMCP indirect

queries. As a consequence, the number of file descriptors used by GDM increased
with every XDMCP chooser restart, which, in some cases, led to memory exhaustion
and a GDM crash. The underlying GDM code has been modified to manage file
descriptors properly, and the problem no longer occurs in this scenario.
(BZ#723515)

• In multi-monitor setups, GDM always displayed the login window on the screen

that was determined as active by the mouse pointer position. This behavior
caused unpredictable login window placement in dual screen setups when using the
NVIDIA's TwinView Dual-Display Architecture because the mouse pointer initially
appeared exactly between the monitors outside of the visible screen. GDM now
uses new logic to ensure that the initial placement of the mouse pointer and the
login window are consistently on one screen. (BZ#670619)

• The GDM simple greeter login window displayed "Suspend", "Restart" and "Shut

Down" buttons even though the buttons were disabled in GDM configuration and the
PolicyKit toolkit disallowed any stop, restart, suspend actions on the system.
With this update, GDM logic responsible for setting up the greeter login window
has been modified and these buttons are no longer displayed under these
circumstances (BZ#645453)

• When authenticating to a system and the fingerprint authentication method was

enabled, but no fingerprint reader was attached to the machine, GDM erroneously
displayed authentication method buttons for a brief moment. With this update,
GDM displays authentication method buttons only if the authentication method is
enabled and a reading device is connected. (BZ#622561)

• GDM did not properly handle its message queue. Therefore, when resetting a

password on user login, GDM displayed an error message from a previous
unsuccessful attempt. The queueing mechanism has been modified, and this problem
no longer occurs. (BZ#708430)

• When logging into a system using LDAP authentication, GDM did not properly

handle LDAP usernames containing backslash characters. As a consequence, such
usernames were not recognized and users were not able to log in even though they
provided valid credentials. With this update, GDM now handles usernames with
backslash characters correctly and users can log in as expected. (BZ#688158)

All users of gdm are advised to upgrade to these updated packages, which fix
these bugs.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 622561 - authentication method buttons show and disappear before they can be used
• BZ - 628462 - [gdm][ru_RU] Cannot enter password (so cannot logon) in gdm using Russian keyboard (layout)
• BZ - 645453 - gdm does not appear to honour gconf key /apps/gdm/simple-greeter/disable_restart_buttons = false or PolicyKit settings
• BZ - 661618 - gdm does not pause, when printing multiple pam messages
• BZ - 670619 - gdm greeter randomly switches screen with nvidia Twinview enabled
• BZ - 688158 - [gdm] Login using LDAP authentication isn't handled well in gdm-binary
• BZ - 708430 - When resetting password, any errors from previous password attemps still show

CVEs

(none)

References

(none)