RHSA-2021:2719 - 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: size_t-to-int conversion vulnerability in the filesystem layer (CVE-2021-33909)
• kernel: use-after-free in net/bluetooth/hci_event.c when destroying an hci_chan (CVE-2021-33034)
• kernel: perf_event_parse_addr_filter memory (CVE-2020-25704)
• kernel: security bypass in certs/blacklist.c and certs/system_keyring.c (CVE-2020-26541)
• kernel: fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent (CVE-2020-35508)

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.z10 Batch source tree (BZ#1968022)

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 - 1886285 - CVE-2020-26541 kernel: security bypass in certs/blacklist.c and certs/system_keyring.c
• BZ - 1895961 - CVE-2020-25704 kernel: perf_event_parse_addr_filter memory
• BZ - 1902724 - CVE-2020-35508 kernel: fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent
• BZ - 1961305 - CVE-2021-33034 kernel: use-after-free in net/bluetooth/hci_event.c when destroying an hci_chan
• BZ - 1968022 - kernel-rt: update RT source tree to the latest RHEL-8.2.z10 Batch source tree
• BZ - 1970273 - CVE-2021-33909 kernel: size_t-to-int conversion vulnerability in the filesystem layer

CVEs

• CVE-2020-25704
• CVE-2020-26541
• CVE-2020-35508
• CVE-2021-33034
• CVE-2021-33909

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/security/vulnerabilities/RHSB-2021-006