RHSA-2021:3440: Red Hat Security Advisory: kernel-rt security and bug fix update

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 Moderate. 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.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: slab-out-of-bounds access in xdr_set_page_base() in net/sunrpc/xdr.c (CVE-2021-38201) 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):
• OSLAT spikes on subset of cpus (BZ#1986063)
• kernel-rt: update RT source tree to the RHEL-8.4.z source tree (BZ#1990013)
• Failure to enter full_nohz due to needless SCHED softirqs (BZ#1990272)
• kernel-rt: Make rcu_normal_after_boot writable (BZ#1995431) Related CVEs:
• CVE-2021-38201: kernel: slab-out-of-bounds access in xdr_set_page_base() in net/sunrpc/xdr.c