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: stack overflow in do_proc_dointvec and proc_skip_spaces (CVE-2022-4378)
• ALSA: pcm: Move rwsem lock inside snd_ctl_elem_read to prevent UAF (CVE-2023-0266)
• kernel: FUSE filesystem low-privileged user privileges escalation (CVE-2023-0386)
• kernel: net: CPU soft lockup in TC mirred egress-to-ingress action (CVE-2022-4269)

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):

• Lazy irq_work does not raise softirq on PREEMPT_RT [rhel-8] (BZ#2172163)
• The latest RHEL 8.7.z3 kernel changes need to be merged into the RT source tree to keep source parity between the two kernels. (BZ#2172278)

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 - 2150272 - CVE-2022-4269 kernel: net: CPU soft lockup in TC mirred egress-to-ingress action
• BZ - 2152548 - CVE-2022-4378 kernel: stack overflow in do_proc_dointvec and proc_skip_spaces
• BZ - 2159505 - CVE-2023-0386 kernel: FUSE filesystem low-privileged user privileges escalation
• BZ - 2163379 - CVE-2023-0266 ALSA: pcm: Move rwsem lock inside snd_ctl_elem_read to prevent UAF

CVEs

• CVE-2022-4269
• CVE-2022-4378
• CVE-2023-0266
• CVE-2023-0386

References

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