RHBA-2015:0551 - Bug Fix Advisory

Topic

Updated gdm packages that fix several bugs are now available for Red Hat
Enterprise Linux 7.

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 the following bugs:

• Previously, the gdm service could not be reliably restarted. Consequently,

when the user ran the "systemctl restart gdm" command, GDM failed to display a
login dialog window and the user was not able to log in. Also, when the user
tried to restart or power off the machine from the top right menu of the GDM
login screen, the reboot or shutdown hung for a minute and then proceeded with
error messages. A patch has been applied to fix these bugs, and the described
problems no longer occur. (BZ#1058061, BZ#1107811)

• Due to a UID comparison bug in the GDM code, users were not allowed to

re-authenticate and unlock the screen if they locked the screen after starting a
VNC session within a shell prompt initiated by the "su" command. Each attempt to
unlock the screen was causing resource leaks, eventually leading to file
descriptor depletion and a GDM crash. This update corrects the erroneous UID
comparison, ensuring that GDM works as intended in the described situation.
(BZ#1086189)

• Prior to this update, if a smart card was used for authentication, the user

was logged in as soon as the authentication was complete. As a consequence, it
was impossible to select a session other than GNOME Classic. This bug has been
fixed, and now any other installed session can be selected by the user.
(BZ#1159056)

Users of gdm are advised to upgrade to these updated packages, which fix these
bugs. The system must be rebooted for this update to take effect.

Solution

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

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64

Fixes

• BZ - 1086189 - [abrt] gdm: g_wakeup_new(): gdm killed by SIGTRAP
• BZ - 1107811 - shutting down or rebooting from GDM hangs for a minute or so
• BZ - 1159056 - pam_pkcs11 with card_only breaks session selection

CVEs

(none)

References

(none)