A kernel-rt security and bug fix update has been released for Red Hat Enterprise Linux 8.2.

RHSA-2021:4875-04: Important: kernel-rt security and bug fix update

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Red Hat Security Advisory

Synopsis: Important: kernel-rt security and bug fix update
Advisory ID: RHSA-2021:4875-01
Product: Red Hat Enterprise Linux
Advisory URL:   https://access.redhat.com/errata/RHSA-2021:4875
Issue date: 2021-11-30
CVE Names: CVE-2020-36385 CVE-2021-20317
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1. Summary:

An update for kernel-rt is now available for Red Hat Enterprise Linux 8.2
Extended Update Support.

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 Real Time EUS (v. 8.2) - x86_64
Red Hat Enterprise Linux Real Time for NFV EUS (v. 8.2) - 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 in drivers/infiniband/core/ucma.c ctx
use-after-free (CVE-2020-36385)

* kernel: timer tree corruption leads to missing wakeup and system freeze
(CVE-2021-20317)

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

Bug Fix(es):

* kernel-rt: update RT source tree to the latest RHEL-8.2.z13 Batch source
tree (BZ#2020969)

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/):

1974319 - CVE-2020-36385 kernel: use-after-free in drivers/infiniband/core/ucma.c ctx use-after-free
2005258 - CVE-2021-20317 kernel: timer tree corruption leads to missing wakeup and system freeze

6. Package List:

Red Hat Enterprise Linux Real Time for NFV EUS (v. 8.2):

Source:
kernel-rt-4.18.0-193.70.1.rt13.120.el8_2.src.rpm

x86_64:
kernel-rt-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-core-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-core-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-debuginfo-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-devel-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-kvm-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-modules-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-modules-extra-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debuginfo-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-devel-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-kvm-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-modules-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-modules-extra-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm

Red Hat Enterprise Linux Real Time EUS (v. 8.2):

Source:
kernel-rt-4.18.0-193.70.1.rt13.120.el8_2.src.rpm

x86_64:
kernel-rt-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-core-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-core-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-debuginfo-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-devel-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-modules-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debug-modules-extra-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debuginfo-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-devel-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-modules-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm
kernel-rt-modules-extra-4.18.0-193.70.1.rt13.120.el8_2.x86_64.rpm

These packages are GPG signed by Red Hat for security. Our key and
details on how to verify the signature are available from
  https://access.redhat.com/security/team/key/

7. References:

  https://access.redhat.com/security/cve/CVE-2020-36385
  https://access.redhat.com/security/cve/CVE-2021-20317
  https://access.redhat.com/security/updates/classification/#important

8. Contact:

The Red Hat security contact is . More contact
details at   https://access.redhat.com/security/team/contact/

Copyright 2021 Red Hat, Inc.