A kernel-rt security and bug fix update has been released for Red Hat Enterprise Linux 8.4.

RHSA-2022:0187-04: Important: kernel-rt security and bug fix update

=====================================================================
Red Hat Security Advisory

Synopsis: Important: kernel-rt security and bug fix update
Advisory ID: RHSA-2022:0187-01
Product: Red Hat Enterprise Linux
Advisory URL:   https://access.redhat.com/errata/RHSA-2022:0187
Issue date: 2022-01-19
CVE Names: CVE-2021-4154 CVE-2021-4155 CVE-2022-0185
=====================================================================

1. Summary:

An update for kernel-rt is now available for Red Hat Enterprise Linux 8.4
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.8.4) - x86_64
Red Hat Enterprise Linux Real Time for NFV EUS (v.8.4) - 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: local privilege escalation by exploiting the fsconfig syscall
parameter leads to container breakout (CVE-2021-4154)

* kernel: xfs: raw block device data leak in XFS_IOC_ALLOCSP IOCTL
(CVE-2021-4155)

* kernel: fs_context: heap overflow in legacy parameter handling
(CVE-2022-0185)

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):

* kernnel-rt-debug: do not call blocking ops when !TASK_RUNNING; state=1
set at [] handle_userfault+0x530/0x1820 (BZ#2029421)

* kernel-rt: update RT source tree to the RHEL-8.4.z6 source tree
(BZ#2029592)

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/):

2034514 - CVE-2021-4154 kernel: local privilege escalation by exploiting the fsconfig syscall parameter leads to container breakout
2034813 - CVE-2021-4155 kernel: xfs: raw block device data leak in XFS_IOC_ALLOCSP IOCTL
2040358 - CVE-2022-0185 kernel: fs_context: heap overflow in legacy parameter handling

6. Package List:

Red Hat Enterprise Linux Real Time for NFV EUS (v.8.4):

Source:
kernel-rt-4.18.0-305.34.2.rt7.107.el8_4.src.rpm

x86_64:
kernel-rt-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-core-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-core-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-debuginfo-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-devel-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-kvm-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-modules-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-modules-extra-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debuginfo-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-devel-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-kvm-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-modules-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-modules-extra-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm

Red Hat Enterprise Linux Real Time EUS (v.8.4):

Source:
kernel-rt-4.18.0-305.34.2.rt7.107.el8_4.src.rpm

x86_64:
kernel-rt-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-core-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-core-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-debuginfo-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-devel-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-modules-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debug-modules-extra-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debuginfo-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-devel-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-modules-4.18.0-305.34.2.rt7.107.el8_4.x86_64.rpm
kernel-rt-modules-extra-4.18.0-305.34.2.rt7.107.el8_4.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-2021-4154
  https://access.redhat.com/security/cve/CVE-2021-4155
  https://access.redhat.com/security/cve/CVE-2022-0185
  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 2022 Red Hat, Inc.