Issued:
2021-08-10
Updated:
2021-08-10

RHSA-2021:3088 - Important: kernel-rt security and bug fix update

Synopsis

Important: kernel-rt security and bug fix update

Type/Severity

Security Advisory Important

Topic

An update for kernel-rt is now available for Red Hat Enterprise Linux 8.

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.

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: race condition in net/can/bcm.c leads to local privilege escalation (CVE-2021-3609)

  • kernel: Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks (CVE-2021-22543)

  • kernel: out-of-bounds write in xt_compat_target_from_user() in net/netfilter/x_tables.c (CVE-2021-22555)

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.z source tree (BZ#1985050)

  • kernel-rt: Merge mm/memcg: Fix kmem_cache_alloc() performance regression (BZ#1987102)

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.

Affected Products

ProductVersionArch
Red Hat Enterprise Linux for x86_64 - Extended Update Support Extension8.8x86_64
Red Hat Enterprise Linux for x86_64 - Extended Update Support Extension8.6x86_64
Red Hat Enterprise Linux for x86_64 - Extended Update Support Extension8.4x86_64
Red Hat Enterprise Linux for x86_64 - Extended Life Cycle8.10x86_64
Red Hat Enterprise Linux for Real Time8x86_64
Red Hat Enterprise Linux for Real Time for NFV8x86_64
Red Hat Enterprise Linux for Real Time for NFV - Telecommunications Update Service8.8x86_64
Red Hat Enterprise Linux for Real Time for NFV - Telecommunications Update Service8.6x86_64
Red Hat Enterprise Linux for Real Time for NFV - Telecommunications Update Service8.4x86_64
Red Hat Enterprise Linux for Real Time - Telecommunications Update Service8.8x86_64
Red Hat Enterprise Linux for Real Time - Telecommunications Update Service8.6x86_64
Red Hat Enterprise Linux for Real Time - Telecommunications Update Service8.4x86_64

Updated Packages

  • kernel-rt-devel-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debug-debuginfo-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-kvm-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debuginfo-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debug-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debug-modules-extra-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-modules-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-core-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debug-modules-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debug-devel-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debug-core-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-modules-extra-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debuginfo-common-x86_64-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-debug-kvm-4.18.0-305.12.1.rt7.84.el8_4.x86_64.rpm
  • kernel-rt-4.18.0-305.12.1.rt7.84.el8_4.src.rpm

Fixes

CVEs

References

Additional information