6.8 - RHSA-2019:0188

Problem Description:

An update for kernel-rt is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Realtime (v. 7) - noarch, x86_64 Red Hat Enterprise Linux for Real Time for NFV (v. 7) - noarch, x86_64

3. Description:

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

* kernel: Use-after-free due to race condition in AF_PACKET implementation (CVE-2018-18559)

For more details about the security issue(s), including the impact, a CVSS score, and other related information, refer to the CVE page(s) listed in the References section.

Bug Fix(es):

* The kernel-rt packages have been upgraded to the 3.10.0-957.5.1 source tree, which provides a number of bug fixes over the previous version. (BZ#1653822)

* Under certain circumstances, the following warning message, which indicated a SCHED_DEADLINE bandwidth tracking mechanism error, occurred:

WARNING: CPU: 8 PID: 19536 at kernel/sched/deadline.c:64 dequeue_task_dl+0x121/0x140

This update fixes the sched_setscheduler() core kernel function, and backports multiple upstream patches to the SCHED_DEADLINE scheduler. As a result, the SCHED_DEADLINE bandwidth tracking mechanism is prevented from error conditions, and the warning message no longer occurs. (BZ#1655439)

4. Solution:

For details on how to apply this update, which includes the changes described in this advisory, refer to:

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

The system must be rebooted for this update to take effect.

5. Bugs fixed (https://bugzilla.redhat.com/):

1641878 - CVE-2018-18559 kernel: Use-after-free due to race condition in AF_PACKET implementation