Important: kernel-rt security and bug fix update

Topic

An update for kernel-rt is now available for Red Hat Enterprise Linux 7.

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: Use After Free in unix_gc() which could result in a local privilege escalation (CVE-2021-0920)
• kernel: xfs: raw block device data leak in XFS_IOC_ALLOCSP IOCTL (CVE-2021-4155)
• kernel: possible privileges escalation due to missing TLB flush (CVE-2022-0330)
• kernel: failing usercopy allows for use-after-free exploitation (CVE-2022-22942)
• kernel: out of bounds write in hid-multitouch.c may lead to escalation of privilege (CVE-2020-0465)
• kernel: double free in bluetooth subsystem when the HCI device initialization fails (CVE-2021-3564)
• kernel: use-after-free in function hci_sock_bound_ioctl() (CVE-2021-3573)
• kernel: possible use-after-free in bluetooth module (CVE-2021-3752)

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: update to the latest RHEL7.9.z12 source tree (BZ#2039101)

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 7 x86_64

Fixes

• BZ - 1920471 - CVE-2020-0465 kernel: out of bounds write in hid-multitouch.c may lead to escalation of privilege
• BZ - 1920480 - CVE-2020-0466 kernel: use after free in eventpoll.c may lead to escalation of privilege
• BZ - 1964139 - CVE-2021-3564 kernel: double free in bluetooth subsystem when the HCI device initialization fails
• BZ - 1966578 - CVE-2021-3573 kernel: use-after-free in function hci_sock_bound_ioctl()
• BZ - 1999544 - CVE-2021-3752 kernel: possible use-after-free in bluetooth module
• 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
• BZ - 2042404 - CVE-2022-0330 kernel: possible privileges escalation due to missing TLB flush
• BZ - 2044809 - CVE-2022-22942 kernel: failing usercopy allows for use-after-free exploitation

CVEs

• CVE-2020-0465
• CVE-2020-0466
• CVE-2021-0920
• CVE-2021-3564
• CVE-2021-3573
• CVE-2021-3752
• CVE-2021-4155
• CVE-2022-0330
• CVE-2022-22942

References

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