USN-3641-1: Linux kernel vulnerabilities

8 May 2018

Several security issues were fixed in the Linux kernel.

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Releases

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)

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.

Learn more about Ubuntu Pro

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.

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