Synopsis

Important: kernel-rt security and bug fix update

Type/Severity

Security Advisory: Important

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: use after free in eventpoll.c may lead to escalation of privilege (CVE-2020-0466)
• kernel: SCSI target (LIO) write to any block on ILO backstore (CVE-2020-28374)
• kernel: Use after free via PI futex state (CVE-2021-3347)
• kernel: race conditions caused by wrong locking in net/vmw_vsock/af_vsock.c (CVE-2021-26708)
• kernel: out-of-bounds read in libiscsi module (CVE-2021-27364)
• kernel: heap buffer overflow in the iSCSI subsystem (CVE-2021-27365)
• Kernel: KVM: host stack overflow due to lazy update IOAPIC (CVE-2020-27152)
• kernel: iscsi: unrestricted access to sessions and handles (CVE-2021-27363)

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):

• kernel-rt possible livelock: WARNING: CPU: 28 PID: 3109 at kernel/ptrace.c:242 ptrace_check_attach+0xdd/0x1a0 (BZ#1925308)
• kernel-rt: update RT source tree to the RHEL-8.3.z3 source tree (BZ#1926369)

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 - 1888886 - CVE-2020-27152 Kernel: KVM: host stack overflow due to lazy update IOAPIC
• BZ - 1899804 - CVE-2020-28374 kernel: SCSI target (LIO) write to any block on ILO backstore
• BZ - 1920480 - CVE-2020-0466 kernel: use after free in eventpoll.c may lead to escalation of privilege
• BZ - 1922249 - CVE-2021-3347 kernel: Use after free via PI futex state
• BZ - 1925588 - CVE-2021-26708 kernel: race conditions caused by wrong locking in net/vmw_vsock/af_vsock.c
• BZ - 1926369 - kernel-rt: update RT source tree to the RHEL-8.3.z3 source tree
• BZ - 1930078 - CVE-2021-27365 kernel: heap buffer overflow in the iSCSI subsystem
• BZ - 1930079 - CVE-2021-27363 kernel: iscsi: unrestricted access to sessions and handles
• BZ - 1930080 - CVE-2021-27364 kernel: out-of-bounds read in libiscsi module

CVEs

• CVE-2020-0466
• CVE-2020-27152
• CVE-2020-28374
• CVE-2021-3347
• CVE-2021-26708
• CVE-2021-27363
• CVE-2021-27364
• CVE-2021-27365

References