RHSA-2021:3445 - Security Advisory

Topic

An update for kernel-rt is now available for Red Hat Enterprise Linux 8.2 Extended Update Support.

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: out-of-bounds write due to a heap buffer overflow in __hidinput_change_resolution_multipliers() of hid-input.c (CVE-2021-0512)
• kernel: use-after-free in route4_change() in net/sched/cls_route.c (CVE-2021-3715)

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#1986064)
• Failure to enter full_nohz due to needless SCHED softirqs (BZ#1990273)
• kernel-rt: update RT source tree to the latest RHEL-8.2.z12 Batch source tree (BZ#1997761)

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 - Telecommunications Update Service 8.2 x86_64
• Red Hat Enterprise Linux for Real Time for NFV - Telecommunications Update Service 8.2 x86_64

Fixes

• BZ - 1974491 - CVE-2021-0512 kernel: out-of-bounds write due to a heap buffer overflow in __hidinput_change_resolution_multipliers() of hid-input.c
• BZ - 1993988 - CVE-2021-3715 kernel: use-after-free in route4_change() in net/sched/cls_route.c

CVEs

• CVE-2021-0512
• CVE-2021-3715

References

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