RHSA-2022:0187 - Security Advisory

Topic

An update for kernel-rt is now available for Red Hat Enterprise Linux 8.4 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: local privilege escalation by exploiting the fsconfig syscall parameter leads to container breakout (CVE-2021-4154)
• kernel: xfs: raw block device data leak in XFS_IOC_ALLOCSP IOCTL (CVE-2021-4155)
• kernel: fs_context: heap overflow in legacy parameter handling (CVE-2022-0185)

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):

• kernnel-rt-debug: do not call blocking ops when !TASK_RUNNING; state=1 set at [<0000000050e86018>] handle_userfault+0x530/0x1820 (BZ#2029421)
• kernel-rt: update RT source tree to the RHEL-8.4.z6 source tree (BZ#2029592)

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 Extension 8.4 x86_64
• Red Hat Enterprise Linux for Real Time - Telecommunications Update Service 8.4 x86_64
• Red Hat Enterprise Linux for Real Time for NFV - Telecommunications Update Service 8.4 x86_64

Fixes

• BZ - 2034514 - CVE-2021-4154 kernel: local privilege escalation by exploiting the fsconfig syscall parameter leads to container breakout
• BZ - 2034813 - CVE-2021-4155 kernel: xfs: raw block device data leak in XFS_IOC_ALLOCSP IOCTL
• BZ - 2040358 - CVE-2022-0185 kernel: fs_context: heap overflow in legacy parameter handling

CVEs

• CVE-2021-4154
• CVE-2021-4155
• CVE-2022-0185

References

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