The systemd packages contain systemd, a system and service manager for Linux, compatible with the SysV and LSB init scripts. It provides aggressive parallelism capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons, and keeps track of processes using Linux cgroups. In addition, it supports snapshotting and restoring of the system state, maintains mount and automount points, and implements an elaborate transactional dependency-based service control logic. It can also work as a drop-in replacement for sysvinit.
* A flaw was found in the way systemd handled empty notification messages. A local attacker could use this flaw to make systemd freeze its execution, preventing further management of system services, system shutdown, or zombie process collection via systemd. (CVE-2016-7795)
* Previously, the udev device manager automatically enabled all memory banks on IBM z System installations. As a consequence, hot plug memory was enabled automatically, which was incorrect. With this update, system architecture checks have been added to the udev rules to address the problem. As a result, hot plug memory is no longer automatically enabled. (BZ#1375603)
A local attacker could use this flaw to make systemd freeze its execution, preventing further management of system services, system shutdown, or zombie process collection via systemd.
Upgrade to the latest packages which contain a patch. Refer to Applying Package Updates to RHEL system for details.
Refer to Red Hat security advisory RHSA-2016:2694 to address this issue and obtain more information.
Following are links for downloading patches to fix the vulnerabilities: