Ubuntu 20.04 LTS: USN-4425-1 Moderate: Kernel Denial of Service

ubuntu

July 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-aws: Linux kernel for Amazon Web Services (AWS) systems

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

- linux-kvm: Linux kernel for cloud environments

- linux-oracle: Linux kernel for Oracle Cloud systems

- linux-riscv: Linux kernel for RISC-V systems

- linux-hwe-5.4: Linux hardware enablement (HWE) kernel

- linux-raspi-5.4: Linux kernel for Raspberry Pi (V8) systems

Details:

It was discovered that the network block device (nbd) implementation in the

Linux kernel did not properly check for error conditions in some

situations. An attacker could possibly use this to cause a denial of

service (system crash). (CVE-2019-16089)

It was discovered that the kernel->user space relay implementation in the

Linux kernel did not properly check return values in some situations. A

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

crash). (...

Read the Full Advisory

Topics Covered

security advisory kernel update Ubuntu Denial of Service kernel issue system crash cloud environments

Update Instructions

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

Ubuntu 20.04 LTS:
  linux-image-5.4.0-1020-aws      5.4.0-1020.20
  linux-image-5.4.0-1021-gcp      5.4.0-1021.21
  linux-image-5.4.0-1021-oracle   5.4.0-1021.21
  linux-image-5.4.0-30-generic    5.4.0-30.34
  linux-image-5.4.0-42-generic    5.4.0-42.46
  linux-image-5.4.0-42-generic-lpae  5.4.0-42.46
  linux-image-5.4.0-42-lowlatency  5.4.0-42.46
  linux-image-aws                 5.4.0.1020.21
  linux-image-gcp                 5.4.0.1021.19
  linux-image-generic             5.4.0.30.37
  linux-image-generic-lpae        5.4.0.42.45
  linux-image-gke                 5.4.0.1021.19
  linux-image-kvm                 5.4.0.1020.19
  linux-image-lowlatency          5.4.0.42.45
  linux-image-oem                 5.4.0.42.45
  linux-image-oem-osp1            5.4.0.42.45
  linux-image-oracle              5.4.0.1021.19
  linux-image-virtual             5.4.0.30.37

Ubuntu 18.04 LTS:
  linux-image-5.4.0-1015-raspi    5.4.0-1015.15~18.04.1
  linux-image-5.4.0-42-generic    5.4.0-42.46~18.04.1
  linux-image-5.4.0-42-generic-lpae  5.4.0-42.46~18.04.1
  linux-image-5.4.0-42-lowlatency  5.4.0-42.46~18.04.1
  linux-image-generic-hwe-18.04   5.4.0.42.46~18.04.35
  linux-image-generic-lpae-hwe-18.04  5.4.0.42.46~18.04.35
  linux-image-gkeop-5.4           5.4.0.42.46~18.04.35
  linux-image-lowlatency-hwe-18.04  5.4.0.42.46~18.04.35
  linux-image-raspi-hwe-18.04     5.4.0.1015.19
  linux-image-snapdragon-hwe-18.04  5.4.0.42.46~18.04.35
  linux-image-virtual-hwe-18.04   5.4.0.42.46~18.04.35

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.