USN-4313-1: Linux kernel vulnerability

30 March 2020

The system could be made to expose sensitive information or run programs as an administrator.

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-azure-5.3 - Linux kernel for Microsoft Azure Cloud systems
  • linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gcp-5.3 - Linux kernel for Google Cloud Platform (GCP) systems
  • linux-gke-5.3 - Linux kernel for Google Container Engine (GKE) systems
  • linux-hwe - Linux hardware enablement (HWE) kernel
  • linux-kvm - Linux kernel for cloud environments
  • linux-oracle - Linux kernel for Oracle Cloud systems
  • linux-oracle-5.3 - Linux kernel buildinfo for version 5.3.0 on 64 bit x86 SMP
  • linux-raspi2 - Linux kernel for Raspberry Pi 2
  • linux-raspi2-5.3 - Linux kernel for Raspberry Pi 2

Details

Manfred Paul discovered that the bpf verifier in the Linux kernel did not
properly calculate register bounds for certain operations. A local attacker
could use this to expose sensitive information (kernel memory) or gain
administrative privileges.

Update instructions

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

Ubuntu 19.10
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.

References