(RHSA-2021:3440) Moderate: kernel-rt security and bug fix update

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)