Important: kernel-rt security and bug fix update

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: mm/mremap.c use-after-free vulnerability (CVE-2022-41222)
• kernel: nfsd buffer overflow by RPC message over TCP with garbage data (CVE-2022-43945)
• kernel: an out-of-bounds vulnerability in i2c-ismt driver (CVE-2022-2873)

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):

• RHEL8-RT: Backport use of a dedicate thread for timer wakeups (BZ#2127204)
• SNO Crashed twice - kernel BUG at lib/list_debug.c:28 (BZ#2132062)
• Cannot trigger kernel dump using NMI on SNO node running PAO and RT kernel [RT-8] (BZ#2139851)
• scheduling while atomic in fpu_clone() -> fpu_inherit_perms() (BZ#2154469)
• The latest RHEL 8.7.z2 kernel changes need to be merged into the RT source tree to keep source parity between the two kernels. (BZ#2159806)

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 8 x86_64
• Red Hat Enterprise Linux for Real Time for NFV 8 x86_64

Fixes

• BZ - 2119048 - CVE-2022-2873 kernel: an out-of-bounds vulnerability in i2c-ismt driver
• BZ - 2138818 - CVE-2022-41222 kernel: mm/mremap.c use-after-free vulnerability
• BZ - 2141752 - CVE-2022-43945 kernel: nfsd buffer overflow by RPC message over TCP with garbage data

CVEs

• CVE-2022-2873
• CVE-2022-41222
• CVE-2022-43945

References

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