RHSA-2021:0774 - Security Advisory

Topic

An update for kernel-rt 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-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

• kernel: bad kfree in auditfilter.c may lead to escalation of privilege (CVE-2020-0444)
• kernel: Local buffer overflow in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c (CVE-2020-25211)
• kernel: locking issue in drivers/tty/tty_jobctrl.c can lead to an use-after-free (CVE-2020-29661)
• kernel: performance counters race condition use-after-free (CVE-2020-14351)
• kernel: ICMP rate limiting can be used for DNS poisoning attack (CVE-2020-25705)

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 RT source tree to the latest RHEL-8.2.z7 Batch source tree (BZ#1915947)
• kernel-rt possible livelock: WARNING: CPU: 28 PID: 3109 at kernel/ptrace.c:242 ptrace_check_attach+0xdd/0x1a0 (BZ#1925309)

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 - Telecommunications Update Service 8.2 x86_64
• Red Hat Enterprise Linux for Real Time for NFV - Telecommunications Update Service 8.2 x86_64

Fixes

• BZ - 1862849 - CVE-2020-14351 kernel: performance counters race condition use-after-free
• BZ - 1877571 - CVE-2020-25211 kernel: Local buffer overflow in ctnetlink_parse_tuple_filter in net/netfilter/nf_conntrack_netlink.c
• BZ - 1894579 - CVE-2020-25705 kernel: ICMP rate limiting can be used for DNS poisoning attack
• BZ - 1906525 - CVE-2020-29661 kernel: locking issue in drivers/tty/tty_jobctrl.c can lead to an use-after-free
• BZ - 1915947 - kernel-rt: update RT source tree to the latest RHEL-8.2.z7 Batch source tree
• BZ - 1920474 - CVE-2020-0444 kernel: bad kfree in auditfilter.c may lead to escalation of privilege

CVEs

• CVE-2020-0444
• CVE-2020-14351
• CVE-2020-25211
• CVE-2020-25705
• CVE-2020-29661

References

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