Important: kernel security and bug fix update

Topic

An update for kernel 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 packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: Use After Free in unix_gc() which could result in a local privilege escalation (CVE-2021-0920)
• kernel: use-after-free in RDMA listen() (CVE-2021-4028)
• kernel: xfs: raw block device data leak in XFS_IOC_ALLOCSP IOCTL (CVE-2021-4155)

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):

• bpf: update to v5.7 (BZ#2019883)
• Backport leftover migrate_disable BPF related change (BZ#2027687)
• assuming atomic context at include/linux/filter.h:597 (BZ#2043427)

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 x86_64 - Extended Update Support 8.2 x86_64
• Red Hat Enterprise Linux Server - AUS 8.2 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 8.2 s390x
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 8.2 ppc64le
• Red Hat Enterprise Linux Server - TUS 8.2 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 8.2 aarch64
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 8.2 ppc64le
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 8.2 x86_64
• Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 8.2 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 8.2 ppc64le
• Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 8.2 aarch64

Fixes

• BZ - 2027201 - CVE-2021-4028 kernel: use-after-free in RDMA listen()
• BZ - 2031930 - CVE-2021-0920 kernel: Use After Free in unix_gc() which could result in a local privilege escalation
• BZ - 2034813 - CVE-2021-4155 kernel: xfs: raw block device data leak in XFS_IOC_ALLOCSP IOCTL

CVEs

• CVE-2021-0920
• CVE-2021-4028
• CVE-2021-4155

References

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