USN-3641-1: Linux kernel vulnerabilities

08 May 2018

linux, linux-aws, linux-azure, linux-euclid, linux-gcp, linux-hwe, linux-kvm, linux-lts-xenial, linux-oem, linux-raspi2, linux-snapdragon vulnerabilities

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-euclid - Linux kernel for Intel Euclid systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-lts-xenial - Linux hardware enablement kernel from Xenial for Trusty
  • linux-oem - Linux kernel for OEM processors
  • linux-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-snapdragon - Linux kernel for Snapdragon processors

Details

Nick Peterson discovered that the Linux kernel did not
properly handle debug exceptions following a MOV/POP to SS
instruction. A local attacker could use this to cause a denial
of service (system crash). This issue only affected the amd64
architecture. (CVE-2018-8897)

Andy Lutomirski discovered that the KVM subsystem of the Linux kernel
did not properly emulate the ICEBP instruction following a MOV/POP
to SS instruction. A local attacker in a KVM virtual machine could
use this to cause a denial of service (guest VM crash) or possibly
escalate privileges inside of the virtual machine. This issue only
affected the i386 and amd64 architectures. (CVE-2018-1087)

Andy Lutomirski discovered that the Linux kernel did not properly
perform error handling on virtualized debug registers. A local
attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code. (CVE-2018-1000199)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 17.10
Ubuntu 16.04
Ubuntu 14.04

After a standard system update you need to reboot your computer to make
all the necessary changes.

ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.