USN-4209-1: Linux kernel vulnerabilities

02 December 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-5.0 - Linux kernel for Amazon Web Services (AWS) systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) 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-osp1 - Linux kernel for OEM processors
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-oracle-5.0 - Linux kernel for Oracle Cloud systems
  • linux-raspi2 - Linux kernel for Raspberry Pi 2

Details

Jann Horn discovered that the OverlayFS and ShiftFS Drivers in the Linux
kernel did not properly handle reference counting during memory mapping
operations when used in conjunction with AUFS. A local attacker could use
this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2019-15794)

It was discovered that a buffer overflow existed in the 802.11 Wi-Fi
configuration interface for the Linux kernel when handling beacon settings.
A local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code. (CVE-2019-16746)

It was discovered that there was a memory leak in the Advanced Buffer
Management functionality of the Netronome NFP4000/NFP6000 NIC Driver in the
Linux kernel during certain error scenarios. A local attacker could use
this to cause a denial of service (memory exhaustion). (CVE-2019-19076)

Update instructions

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

Ubuntu 19.04
Ubuntu 18.04

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.