USN-4325-1: Linux kernel vulnerabilities

07 April 2020

Several security issues were fixed in the Linux kernel.

Releases

Packages

  • linux-azure - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke-5.0 - Linux kernel for Google Container Engine (GKE) systems
  • linux-oem-osp1 - Linux kernel for OEM processors
  • linux-oracle-5.0 - Linux kernel for Oracle Cloud systems

Details

It was discovered that the IPMI message handler implementation in the Linux
kernel did not properly deallocate memory in certain situations. A local
attacker could use this to cause a denial of service (kernel memory
exhaustion). (CVE-2019-19046)

Al Viro discovered that the vfs layer in the Linux kernel contained a use-
after-free vulnerability. A local attacker could use this to cause a denial
of service (system crash) or possibly expose sensitive information (kernel
memory). (CVE-2020-8428)

Update instructions

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

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.