RHSA-2021:3725 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 7.4 Advanced 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 packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks (CVE-2021-22543)
• kernel: out-of-bounds write in xt_compat_target_from_user() in net/netfilter/x_tables.c (CVE-2021-22555)
• kernel: race condition for removal of the HCI controller (CVE-2021-32399)
• kernel: powerpc: KVM guest OS users can cause host OS memory corruption (CVE-2021-37576)

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):

• [CKI kernel builds]: x86 binaries in non-x86 kernel rpms breaks systemtap [7.9.z] (BZ#1975161)

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 7.4 x86_64

Fixes

• BZ - 1965461 - CVE-2021-22543 kernel: Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks
• BZ - 1970807 - CVE-2021-32399 kernel: race condition for removal of the HCI controller
• BZ - 1980101 - CVE-2021-22555 kernel: out-of-bounds write in xt_compat_target_from_user() in net/netfilter/x_tables.c
• BZ - 1986506 - CVE-2021-37576 kernel: powerpc: KVM guest OS users can cause host OS memory corruption

CVEs

• CVE-2021-22543
• CVE-2021-22555
• CVE-2021-32399
• CVE-2021-37576

References

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