RHSA-2021:4648: Important: kernel-rt security and bug fix update

Published Nov 15, 2021
·
Updated

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: Insufficient validation of user-supplied sizes for the MSGCRYPTO message type (CVE-2021-43267) kernel: timer tree corruption leads to missing wakeup and system freeze (CVE-2021-20317) kernel: fuse: stall on CPU can occur because a retry loop continually finds the same bad inode (CVE-2021-28950) 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 RHEL-8.4.z5 source tree (BZ#2017122)

Affected Software

15 affected componentsFixes available
redhat/kernel-rt<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-core<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-debug<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-debug-core<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-debug-debuginfo<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-debug-devel<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-debug-modules<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-debug-modules-extra<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-debuginfo<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-devel<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-modules<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-modules-extra<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-debug-kvm<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4
redhat/kernel-rt-kvm<4.18.0-305.28.1.rt7.100.el8_4
4.18.0-305.28.1.rt7.100.el8_4

Remediation

Event History

Mar 14, 2026
Advisory Published
via Red Hat·02:40 PM
Data Sourced
via Red Hat·02:40 PM
RemedyDescriptionAffected Software
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Frequently Asked Questions

1

What is the severity of RHSA-2021:4648?

The severity of RHSA-2021:4648 is considered to be moderate due to the information leakage and potential impact on system security.

2

How do I fix RHSA-2021:4648?

To fix RHSA-2021:4648, update the kernel-rt packages to version 4.18.0-305.28.1.rt7.100.el8_4 or later.

3

Which systems are affected by RHSA-2021:4648?

RHSA-2021:4648 affects systems running the kernel-rt packages prior to version 4.18.0-305.28.1.rt7.100.el8_4 on Red Hat Enterprise Linux.

4

What vulnerabilities does RHSA-2021:4648 address?

RHSA-2021:4648 addresses the CVE-2021-43267 vulnerability related to insufficient validation of user-supplied sizes for the MSG_CRYPTO message type.

5

Is a system reboot required after applying the fix for RHSA-2021:4648?

Yes, a system reboot is required to apply the kernel updates from RHSA-2021:4648.

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