RHSA-2021:3801 - Security Advisory

Topic

An update for kernel 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 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: powerpc: KVM guest OS users can cause host OS memory corruption (CVE-2021-37576)
• kernel: SVM nested virtualization issue in KVM (AVIC support) (CVE-2021-3653)
• kernel: SVM nested virtualization issue in KVM (VMLOAD/VMSAVE) (CVE-2021-3656)

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 panic due to double fault with DLM reporting for socket error "sk_err=32/0" (BZ#1834878)
• "MFW indication via attention" message getting logged frequently after every 5 minutes (BZ#1854544)
• lpfc fails to discovery in pt2pt with "2754 PRLI failure DID:0000EF Status:x9/x91e00, data: x0" (BZ#1922479)
• pcpu_get_vm_areas using most memory from VmallocUsed (BZ#1970618)
• RHEL 7.9.z [qedf driver] Racing condition between qedf_cleanup_fcport and releasing command after timeout (BZ#1982702)
• [Azure] RHEL 7.9 reports GPU/IB topology incorrectly on some Azure SKUs (BZ#1984128)
• [stable guest ABI]Hot add CPU after migration cause guest hang (BZ#1991856)
• i40e driver crash at RIP: i40e_config_vf_promiscuous_mode+0x165 (BZ#1993850)
• [nfs] Performance issue since commit 5a4f6f11951e (BZ#1995649)
• [kernel] Indefinite waiting for RCU callback while removing cgroup (BZ#2000973)

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 7 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Virtualization Host 4 for RHEL 7 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• BZ - 1965461 - CVE-2021-22543 kernel: Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks
• BZ - 1983686 - CVE-2021-3653 kernel: SVM nested virtualization issue in KVM (AVIC support)
• BZ - 1983988 - CVE-2021-3656 kernel: SVM nested virtualization issue in KVM (VMLOAD/VMSAVE)
• BZ - 1986506 - CVE-2021-37576 kernel: powerpc: KVM guest OS users can cause host OS memory corruption

CVEs

• CVE-2021-3653
• CVE-2021-3656
• CVE-2021-22543
• CVE-2021-37576

References

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