Ubuntu 20.04 LTS USN-4525-1: Critical DoS Issues in Linux Kernel

ubuntu

September 22, 2020

Several security issues were fixed in the Linux kernel.

Summary

Several security issues were fixed in the Linux kernel.

Software Description:

- linux: Linux kernel

- linux-azure: Linux kernel for Microsoft Azure Cloud systems

- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems

- linux-oracle: Linux kernel for Oracle Cloud systems

Details:

It was discovered that the AMD Cryptographic Coprocessor device driver in

the Linux kernel did not properly deallocate memory in some situations. A

local attacker could use this to cause a denial of service (memory

exhaustion). (CVE-2019-18808)

It was discovered that the Conexant 23885 TV card device driver for the

Linux kernel did not properly deallocate memory in some error conditions. A

local attacker could use this to cause a denial of service (memory

exhaustion). (CVE-2019-19054)

It was discovered that the VFIO PCI driver in the Linux kernel did not

properly handle attempts to access disabled memory spaces. A local attacker

could use this to cause a denial of service (system crash).

(CV...

Read the Full Advisory

Topics Covered

security advisory DoS Ubuntu kernel memory exhaustion system crash security issues

Update Instructions

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

Ubuntu 20.04 LTS:
  linux-image-5.4.0-1025-gcp      5.4.0-1025.25
  linux-image-5.4.0-1025-oracle   5.4.0-1025.25
  linux-image-5.4.0-1026-azure    5.4.0-1026.26
  linux-image-5.4.0-48-generic    5.4.0-48.52
  linux-image-5.4.0-48-generic-lpae  5.4.0-48.52
  linux-image-5.4.0-48-lowlatency  5.4.0-48.52
  linux-image-azure               5.4.0.1026.25
  linux-image-gcp                 5.4.0.1025.22
  linux-image-generic             5.4.0.48.51
  linux-image-generic-lpae        5.4.0.48.51
  linux-image-gke                 5.4.0.1025.22
  linux-image-lowlatency          5.4.0.48.51
  linux-image-oem                 5.4.0.48.51
  linux-image-oem-osp1            5.4.0.48.51
  linux-image-oracle              5.4.0.1025.22
  linux-image-virtual             5.4.0.48.51

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.