A kernel security and bug fix update has been released for Red Hat Enterprise Linux 8.

RHSA-2021:5227-07: Moderate: kernel security and bug fix update

=====================================================================
Red Hat Security Advisory

Synopsis: Moderate: kernel security and bug fix update
Advisory ID: RHSA-2021:5227-01
Product: Red Hat Enterprise Linux
Advisory URL:   https://access.redhat.com/errata/RHSA-2021:5227
Issue date: 2021-12-21
CVE Names: CVE-2021-20321
=====================================================================

1. Summary:

An update for kernel 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.

2. Relevant releases/architectures:

Red Hat CodeReady Linux Builder (v. 8) - aarch64, ppc64le, x86_64
Red Hat Enterprise Linux BaseOS (v. 8) - aarch64, noarch, ppc64le, s390x, x86_64

3. Description:

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

Security Fix(es):

* kernel: In Overlayfs missing a check for a negative dentry before calling
vfs_rename() (CVE-2021-20321)

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):

* panic while breaking a lease/delegation after user mode helper invocation
(BZ#2010333)

* The ASR driver is causing a system crash in RHEL8.4 compared to RHEL8.3
due to kernel changes (BZ#2016384)

* RHEL8: DFS provided SMB shares are not accessible following unprivileged
access (BZ#2017177)

* Avoid hitting the rtnl_trylock/restart_syscall logic in net-sysfs when
possible (BZ#2021165)

* RHEL8: x86/Kconfig: Do not enable AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
(BZ#2024678)

* RHEL8.4-[Regression][P10][DD2.0][Rainier/Denali] - system crashed while
offlining and onlining cores (BZ#2026450)

4. 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.

5. Bugs fixed (  https://bugzilla.redhat.com/):

2013242 - CVE-2021-20321 kernel: In Overlayfs missing a check for a negative dentry before calling vfs_rename()

6. Package List:

Red Hat Enterprise Linux BaseOS (v. 8):

Source:
kernel-4.18.0-348.7.1.el8_5.src.rpm

aarch64:
bpftool-4.18.0-348.7.1.el8_5.aarch64.rpm
bpftool-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-core-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-cross-headers-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debug-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debug-core-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debug-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debug-devel-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debug-modules-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debug-modules-extra-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debuginfo-common-aarch64-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-devel-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-headers-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-modules-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-modules-extra-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-tools-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-tools-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-tools-libs-4.18.0-348.7.1.el8_5.aarch64.rpm
perf-4.18.0-348.7.1.el8_5.aarch64.rpm
perf-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
python3-perf-4.18.0-348.7.1.el8_5.aarch64.rpm
python3-perf-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm

noarch:
kernel-abi-stablelists-4.18.0-348.7.1.el8_5.noarch.rpm
kernel-doc-4.18.0-348.7.1.el8_5.noarch.rpm

ppc64le:
bpftool-4.18.0-348.7.1.el8_5.ppc64le.rpm
bpftool-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-core-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-cross-headers-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debug-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debug-core-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debug-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debug-devel-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debug-modules-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debug-modules-extra-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debuginfo-common-ppc64le-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-devel-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-headers-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-modules-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-modules-extra-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-tools-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-tools-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-tools-libs-4.18.0-348.7.1.el8_5.ppc64le.rpm
perf-4.18.0-348.7.1.el8_5.ppc64le.rpm
perf-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
python3-perf-4.18.0-348.7.1.el8_5.ppc64le.rpm
python3-perf-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm

s390x:
bpftool-4.18.0-348.7.1.el8_5.s390x.rpm
bpftool-debuginfo-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-core-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-cross-headers-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-debug-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-debug-core-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-debug-debuginfo-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-debug-devel-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-debug-modules-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-debug-modules-extra-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-debuginfo-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-debuginfo-common-s390x-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-devel-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-headers-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-modules-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-modules-extra-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-tools-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-tools-debuginfo-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-zfcpdump-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-zfcpdump-core-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-zfcpdump-debuginfo-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-zfcpdump-devel-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-zfcpdump-modules-4.18.0-348.7.1.el8_5.s390x.rpm
kernel-zfcpdump-modules-extra-4.18.0-348.7.1.el8_5.s390x.rpm
perf-4.18.0-348.7.1.el8_5.s390x.rpm
perf-debuginfo-4.18.0-348.7.1.el8_5.s390x.rpm
python3-perf-4.18.0-348.7.1.el8_5.s390x.rpm
python3-perf-debuginfo-4.18.0-348.7.1.el8_5.s390x.rpm

x86_64:
bpftool-4.18.0-348.7.1.el8_5.x86_64.rpm
bpftool-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-core-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-cross-headers-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debug-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debug-core-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debug-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debug-devel-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debug-modules-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debug-modules-extra-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debuginfo-common-x86_64-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-devel-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-headers-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-modules-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-modules-extra-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-tools-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-tools-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-tools-libs-4.18.0-348.7.1.el8_5.x86_64.rpm
perf-4.18.0-348.7.1.el8_5.x86_64.rpm
perf-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
python3-perf-4.18.0-348.7.1.el8_5.x86_64.rpm
python3-perf-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm

Red Hat CodeReady Linux Builder (v. 8):

aarch64:
bpftool-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debug-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-debuginfo-common-aarch64-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-tools-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
kernel-tools-libs-devel-4.18.0-348.7.1.el8_5.aarch64.rpm
perf-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm
python3-perf-debuginfo-4.18.0-348.7.1.el8_5.aarch64.rpm

ppc64le:
bpftool-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debug-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-debuginfo-common-ppc64le-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-tools-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
kernel-tools-libs-devel-4.18.0-348.7.1.el8_5.ppc64le.rpm
perf-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm
python3-perf-debuginfo-4.18.0-348.7.1.el8_5.ppc64le.rpm

x86_64:
bpftool-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debug-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-debuginfo-common-x86_64-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-tools-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
kernel-tools-libs-devel-4.18.0-348.7.1.el8_5.x86_64.rpm
perf-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm
python3-perf-debuginfo-4.18.0-348.7.1.el8_5.x86_64.rpm

These packages are GPG signed by Red Hat for security. Our key and
details on how to verify the signature are available from
  https://access.redhat.com/security/team/key/

7. References:

  https://access.redhat.com/security/cve/CVE-2021-20321
  https://access.redhat.com/security/updates/classification/#moderate

8. Contact:

The Red Hat security contact is . More contact
details at   https://access.redhat.com/security/team/contact/

Copyright 2021 Red Hat, Inc.