Important: kernel security and bug fix update

Topic

An update for kernel is now available for Red Hat Enterprise Linux 7.7 Advanced Update Support, Red Hat Enterprise Linux 7.7 Telco Extended Update Support, and Red Hat Enterprise Linux 7.7 Update Services for SAP Solutions.

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 packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: Use After Free in unix_gc() which could result in a local privilege escalation (CVE-2021-0920)
• kernel: use-after-free in RDMA listen() (CVE-2021-4028)
• kernel: fget: check that the fd still exists after getting a ref to it (CVE-2021-4083)
• kernel: failing usercopy allows for use-after-free exploitation (CVE-2022-22942)

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):

• guest using rtl8139 can not connect to network (BZ#2063889)

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 Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.7 x86_64

Fixes

• BZ - 2027201 - CVE-2021-4028 kernel: use-after-free in RDMA listen()
• BZ - 2029923 - CVE-2021-4083 kernel: fget: check that the fd still exists after getting a ref to it
• BZ - 2031930 - CVE-2021-0920 kernel: Use After Free in unix_gc() which could result in a local privilege escalation
• BZ - 2044809 - CVE-2022-22942 kernel: failing usercopy allows for use-after-free exploitation

CVEs

• CVE-2021-0920
• CVE-2021-4028
• CVE-2021-4083
• CVE-2022-22942

References

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