Important: kernel security and bug fix update

Topic

An update for kernel is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.4 Telecommunications Update Service, and Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions.

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 packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: net/sched: cls_u32 component reference counter leak if tcf_change_indev() fails (CVE-2023-3609)
• kernel: net/sched: cls_fw component can be exploited as result of failure in tcf_change_indev function (CVE-2023-3776)
• kernel: net/sched: Use-after-free vulnerabilities in the net/sched classifiers: cls_fw, cls_u32 and cls_route (CVE-2023-4128)
• kernel: netfilter: NULL pointer dereference in nf_tables due to zeroed list head (CVE-2023-1095)
• kernel: save/restore speculative MSRs during S3 suspend/resume (CVE-2023-1637)

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):

• avoid unnecessary page fault retires on shared memory types (BZ#2221102)
• [Hyper-V][RHEL-8] Fix VM crash/hang Issues due to fast VF add/remove events (BZ#2227261)
• kernel-devel RPM cross-compiled by CKI contains host-arch scripts (BZ#2232139)
• iavf: hang in iavf_remove() - SNO node hangs after running systemctl reboot (BZ#2232405)
• netfilter: RHEL 8.8 phase 2 backports from upstream (BZ#2236818)

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 Server - AUS 8.4 x86_64
• Red Hat Enterprise Linux Server - TUS 8.4 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 8.4 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 8.4 x86_64

Fixes

• BZ - 2173973 - CVE-2023-1095 kernel: netfilter: NULL pointer dereference in nf_tables due to zeroed list head
• BZ - 2181891 - CVE-2023-1637 kernel: save/restore speculative MSRs during S3 suspend/resume
• BZ - 2225097 - CVE-2023-3776 kernel: net/sched: cls_fw component can be exploited as result of failure in tcf_change_indev function
• BZ - 2225201 - CVE-2023-3609 kernel: net/sched: cls_u32 component reference counter leak if tcf_change_indev() fails
• BZ - 2225511 - CVE-2023-4128 kernel: net/sched: Use-after-free vulnerabilities in the net/sched classifiers: cls_fw, cls_u32 and cls_route

CVEs

• CVE-2023-1095
• CVE-2023-1637
• CVE-2023-3609
• CVE-2023-3776
• CVE-2023-4128

References

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