RHSA-2021:2316 - Security Advisory

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: Integer overflow in Intel(R) Graphics Drivers (CVE-2020-12362)
• kernel: Use after free via PI futex state (CVE-2021-3347)
• kernel: use-after-free in n_tty_receive_buf_common function in drivers/tty/n_tty.c (CVE-2020-8648)
• kernel: Improper input validation in some Intel(R) Graphics Drivers (CVE-2020-12363)
• kernel: Null pointer dereference in some Intel(R) Graphics Drivers (CVE-2020-12364)
• kernel: Speculation on pointer arithmetic against bpf_context pointer (CVE-2020-27170)

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):

• lru-add-drain workqueue on RT is allocated without being used (BZ#1894587)
• kernel-rt: update to the latest RHEL7.9.z source tree (BZ#1953118)

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
• Red Hat Enterprise Linux for Real Time for NFV 7 x86_64

Fixes

• BZ - 1802559 - CVE-2020-8648 kernel: use-after-free in n_tty_receive_buf_common function in drivers/tty/n_tty.c
• BZ - 1894587 - lru-add-drain workqueue on RT is allocated without being used
• BZ - 1922249 - CVE-2021-3347 kernel: Use after free via PI futex state
• BZ - 1930246 - CVE-2020-12362 kernel: Integer overflow in Intel(R) Graphics Drivers
• BZ - 1930249 - CVE-2020-12363 kernel: Improper input validation in some Intel(R) Graphics Drivers
• BZ - 1930251 - CVE-2020-12364 kernel: Null pointer dereference in some Intel(R) Graphics Drivers
• BZ - 1940627 - CVE-2020-27170 kernel: Speculation on pointer arithmetic against bpf_context pointer

CVEs

• CVE-2020-8648
• CVE-2020-12362
• CVE-2020-12363
• CVE-2020-12364
• CVE-2020-27170
• CVE-2021-3347

References

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