Important: kernel security and bug fix update

Synopsis

Important: kernel security and bug fix update

Type/Severity

Security Advisory: Important

Topic

An update for kernel is now available for Red Hat Enterprise Linux 7.4 Advanced Update Support, Red Hat Enterprise Linux 7.4 Telco Extended Update Support, and Red Hat Enterprise Linux 7.4 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 __blk_drain_queue() function in block/blk-core.c (CVE-2018-20856)
  
• Kernel: KVM: potential use-after-free via kvm_ioctl_create_device() (CVE-2019-6974)
  
• kernel: kvm: guest userspace to guest kernel write (CVE-2018-10853)
  
• kernel: TLB flush happens too late on mremap (CVE-2018-18281)
  
• kernel: fix race condition between mmget_not_zero()/get_task_mm() and core dumping (CVE-2019-11599)
  

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 softlockup in mem_cgroup_reparent_charges with 800GB guests (BZ#1770111)
  
• [RHEL7.7] Refined TSC clocksource calibration occasionally fails on some SkyLake-X servers (BZ#1775682)

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
• Red Hat Enterprise Linux Server - TUS 7.4 x86_64
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.4 ppc64le
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.4 x86_64

Fixes

• BZ - 1589890 - CVE-2018-10853 kernel: kvm: guest userspace to guest kernel write
• BZ - 1645121 - CVE-2018-18281 kernel: TLB flush happens too late on mremap
• BZ - 1671913 - CVE-2019-6974 Kernel: KVM: potential use-after-free via kvm_ioctl_create_device()
• BZ - 1705937 - CVE-2019-11599 kernel: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
• BZ - 1738705 - CVE-2018-20856 kernel: Use-after-free in __blk_drain_queue() function in block/blk-core.c

CVEs

• CVE-2018-10853
• CVE-2018-18281
• CVE-2018-20856
• CVE-2019-6974
• CVE-2019-11599

References

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