USN-3444-1: Linux kernel vulnerabilities

10 October 2017

linux, linux-aws, linux-gke, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 16.04 LTS

Summary

Several security issues were fixed in the Linux kernel.

Software Description

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-gke - Linux kernel for Google Container Engine (GKE) systems
  • linux-kvm - Linux kernel for cloud environments
  • linux-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-snapdragon - Linux kernel for Snapdragon processors

Details

Jan H. Schönherr discovered that the Xen subsystem did not properly handle block IO merges correctly in some situations. An attacker in a guest vm could use this to cause a denial of service (host crash) or possibly gain administrative privileges in the host. (CVE-2017-12134)

Andrey Konovalov discovered that a divide-by-zero error existed in the TCP stack implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-14106)

Otto Ebeling discovered that the memory manager in the Linux kernel did not properly check the effective UID in some situations. A local attacker could use this to expose sensitive information. (CVE-2017-14140)

Update instructions

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

Ubuntu 16.04 LTS
linux-image-4.4.0-1008-kvm - 4.4.0-1008.13
linux-image-4.4.0-1032-gke - 4.4.0-1032.32
linux-image-4.4.0-1038-aws - 4.4.0-1038.47
linux-image-4.4.0-1075-raspi2 - 4.4.0-1075.83
linux-image-4.4.0-1077-snapdragon - 4.4.0-1077.82
linux-image-4.4.0-97-generic - 4.4.0-97.120
linux-image-4.4.0-97-generic-lpae - 4.4.0-97.120
linux-image-4.4.0-97-lowlatency - 4.4.0-97.120
linux-image-4.4.0-97-powerpc-e500mc - 4.4.0-97.120
linux-image-4.4.0-97-powerpc-smp - 4.4.0-97.120
linux-image-4.4.0-97-powerpc64-emb - 4.4.0-97.120
linux-image-4.4.0-97-powerpc64-smp - 4.4.0-97.120
linux-image-aws - 4.4.0.1038.40
linux-image-generic - 4.4.0.97.102
linux-image-generic-lpae - 4.4.0.97.102
linux-image-gke - 4.4.0.1032.33
linux-image-kvm - 4.4.0.1008.8
linux-image-lowlatency - 4.4.0.97.102
linux-image-powerpc-e500mc - 4.4.0.97.102
linux-image-powerpc-smp - 4.4.0.97.102
linux-image-powerpc64-emb - 4.4.0.97.102
linux-image-powerpc64-smp - 4.4.0.97.102
linux-image-raspi2 - 4.4.0.1075.75
linux-image-snapdragon - 4.4.0.1077.69

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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.

References