Important: kernel-rt security and bug fix update

Topic

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.

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: Small table perturb size in the TCP source port generation algorithm can lead to information leak (CVE-2022-1012)
• kernel: race condition in perf_event_open leads to privilege escalation (CVE-2022-1729)
• kernel: a use-after-free write in the netfilter subsystem can lead to privilege escalation to root (CVE-2022-32250)
• kernel: cgroup: Use open-time creds and namespace for migration perm checks (CVE-2021-4197)
• kernel: Race condition in races in sk_peer_pid and sk_peer_cred accesses (CVE-2021-4203)
• kernel: the copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check (CVE-2020-29368)

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.z10 source tree (BZ#2087922)

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

• Red Hat Enterprise Linux for Real Time - Telecommunications Update Service 8.4 x86_64

Fixes

• BZ - 1903244 - CVE-2020-29368 kernel: the copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check
• BZ - 2035652 - CVE-2021-4197 kernel: cgroup: Use open-time creds and namespace for migration perm checks
• BZ - 2036934 - CVE-2021-4203 kernel: Race condition in races in sk_peer_pid and sk_peer_cred accesses
• BZ - 2064604 - CVE-2022-1012 kernel: Small table perturb size in the TCP source port generation algorithm can lead to information leak
• BZ - 2086753 - CVE-2022-1729 kernel: race condition in perf_event_open leads to privilege escalation
• BZ - 2092427 - CVE-2022-32250 kernel: a use-after-free write in the netfilter subsystem can lead to privilege escalation to root

CVEs

• CVE-2020-29368
• CVE-2021-4197
• CVE-2021-4203
• CVE-2022-1012
• CVE-2022-1729
• CVE-2022-32250

References

• https://access.redhat.com/security/updates/classification/#important