Ubuntu 18.04 LTS USN-4484-1 Critical: linux-hwe Denial of Service

ubuntu

September 2, 2020

The system could be made to crash or run programs as an administrator.

Summary

The system could be made to crash or run programs as an administrator.

Software Description:

- linux-aws-5.3: Linux kernel for Amazon Web Services (AWS) systems

- linux-gke-5.3: Linux kernel for Google Container Engine (GKE) systems

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

- linux-raspi2-5.3: Linux kernel for Raspberry Pi (V8) systems

Details:

It was discovered that the cgroup v2 subsystem in the Linux kernel did not

properly perform reference counting in some situations, leading to a NULL

pointer dereference. A local attacker could use this to cause a denial of

service or possibly gain administrative privileges. (CVE-2020-14356)

Topics Covered

security advisory denial of service ubuntu linux kernel crash administrative privileges

Update Instructions

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

Ubuntu 18.04 LTS:
  linux-image-5.3.0-1032-raspi2   5.3.0-1032.34
  linux-image-5.3.0-1034-aws      5.3.0-1034.36
  linux-image-5.3.0-1034-gke      5.3.0-1034.36
  linux-image-5.3.0-66-generic    5.3.0-66.60
  linux-image-5.3.0-66-lowlatency  5.3.0-66.60
  linux-image-aws                 5.3.0.1034.33
  linux-image-gke-5.3             5.3.0.1034.19
  linux-image-gkeop-5.3           5.3.0.66.123
  linux-image-raspi2-hwe-18.04    5.3.0.1032.22

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.