USN-4135-1: Linux kernel vulnerabilities

18 September 2019

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux - Linux kernel
  • linux-aws - Linux kernel for Amazon Web Services (AWS) systems
  • linux-aws-hwe - Linux kernel for Amazon Web Services (AWS-HWE) systems
  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke-4.15 - Linux kernel for Google Container Engine (GKE) systems
  • linux-gke-5.0 - Linux kernel for Google Container Engine (GKE) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oem - Linux kernel for OEM processors
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-snapdragon - Linux kernel for Snapdragon processors

Details

Peter Pi discovered a buffer overflow in the virtio network backend
(vhost_net) implementation in the Linux kernel. An attacker in a guest may
be able to use this to cause a denial of service (host OS crash) or
possibly execute arbitrary code in the host OS. (CVE-2019-14835)

It was discovered that the Linux kernel on PowerPC architectures did not
properly handle Facility Unavailable exceptions in some situations. A local
attacker could use this to expose sensitive information. (CVE-2019-15030)

It was discovered that the Linux kernel on PowerPC architectures did not
properly handle exceptions on interrupts in some situations. A local
attacker could use this to expose sensitive information. (CVE-2019-15031)

Update instructions

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

Ubuntu 19.04
Ubuntu 18.04
Ubuntu 16.04

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.