[RHSA-2022:6991-01] Important: kernel-rt security and bug fix update

Tue Oct 18 14:57:29 UTC 2022

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):

* A use-after-free in cls_route filter implementation may lead to privilege
escalation (CVE-2022-2588)

* Information leak in the IPv6 implementation (CVE-2021-45485)

* Information leak in the IPv4 implementation (CVE-2021-45486)

* Incomplete cleanup of multi-core shared buffers (aka SBDR)
(CVE-2022-21123)

* Incomplete cleanup of microarchitectural fill buffers (aka SBDS)
(CVE-2022-21125)

* Incomplete cleanup in specific special register write operations (aka
DRPW) (CVE-2022-21166)

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):

* update RT source tree to the RHEL-8.4.z12 source tree (BZ#2119160)

* using __this_cpu_add() in preemptible [00000000] - caller is
__mod_memcg_lruvec_state+0x69/0x1c0 [None8.4.0.z] (BZ#2124454)

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/):

2039911 - CVE-2021-45485 kernel: information leak in the IPv6 implementation
2039914 - CVE-2021-45486 kernel: information leak in the IPv4 implementation
2090237 - CVE-2022-21123 hw: cpu: Incomplete cleanup of multi-core shared buffers (aka SBDR)
2090240 - CVE-2022-21125 hw: cpu: Incomplete cleanup of microarchitectural fill buffers (aka SBDS)
2090241 - CVE-2022-21166 hw: cpu: Incomplete cleanup in specific special register write operations (aka DRPW)
2114849 - CVE-2022-2588 kernel: a use-after-free in cls_route filter implementation may lead to privilege escalation

6. Package List:

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

Source:
kernel-rt-4.18.0-305.65.1.rt7.137.el8_4.src.rpm

x86_64:
kernel-rt-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-core-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-core-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-debuginfo-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-devel-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-kvm-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-modules-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-modules-extra-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debuginfo-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-devel-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-kvm-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-modules-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-modules-extra-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm

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

Source:
kernel-rt-4.18.0-305.65.1.rt7.137.el8_4.src.rpm

x86_64:
kernel-rt-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-core-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-core-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-debuginfo-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-devel-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-modules-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debug-modules-extra-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debuginfo-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-debuginfo-common-x86_64-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-devel-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-modules-4.18.0-305.65.1.rt7.137.el8_4.x86_64.rpm
kernel-rt-modules-extra-4.18.0-305.65.1.rt7.137.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-2021-45485
https://access.redhat.com/security/cve/CVE-2021-45486
https://access.redhat.com/security/cve/CVE-2022-2588
https://access.redhat.com/security/cve/CVE-2022-21123
https://access.redhat.com/security/cve/CVE-2022-21125
https://access.redhat.com/security/cve/CVE-2022-21166
https://access.redhat.com/security/updates/classification/#important

8. Contact:

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

Copyright 2022 Red Hat, Inc.
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