Ubuntu 20.04 LTS: Important Kernel Updates for USN-4389-1 Released

ubuntu

June 9, 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-azure: Linux kernel for Microsoft Azure Cloud 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

Details:

It was discovered that the F2FS file system implementation in the Linux

kernel did not properly perform bounds checking on xattrs in some

situations. A local attacker could possibly use this to expose sensitive

information (kernel memory). (CVE-2020-0067)

It was discovered that memory contents previously stored in

microarchitectural special registers after RDRAND, RDSEED, and SGX EGETKEY

read operations on Intel client and Xeon E3 processors may be briefly

exposed to processes on the same or different processor cores. A local

attacker could use this to expose sensitive information....

Read the Full Advisory

Topics Covered

security advisory denial of service kernel information disclosure ubuntu bounds checking

Update Instructions

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

Ubuntu 20.04 LTS:
  linux-image-5.4.0-1015-aws      5.4.0-1015.15
  linux-image-5.4.0-1015-gcp      5.4.0-1015.15
  linux-image-5.4.0-1015-kvm      5.4.0-1015.15
  linux-image-5.4.0-1015-oracle   5.4.0-1015.15
  linux-image-5.4.0-1016-azure    5.4.0-1016.16
  linux-image-5.4.0-37-generic    5.4.0-37.41
  linux-image-5.4.0-37-generic-lpae  5.4.0-37.41
  linux-image-5.4.0-37-lowlatency  5.4.0-37.41
  linux-image-aws                 5.4.0.1015.16
  linux-image-azure               5.4.0.1016.16
  linux-image-gcp                 5.4.0.1015.14
  linux-image-generic             5.4.0.37.40
  linux-image-generic-hwe-20.04   5.4.0.37.40
  linux-image-generic-lpae        5.4.0.37.40
  linux-image-generic-lpae-hwe-20.04  5.4.0.37.40
  linux-image-gke                 5.4.0.1015.14
  linux-image-kvm                 5.4.0.1015.14
  linux-image-lowlatency          5.4.0.37.40
  linux-image-lowlatency-hwe-20.04  5.4.0.37.40
  linux-image-oem                 5.4.0.37.40
  linux-image-oem-osp1            5.4.0.37.40
  linux-image-oracle              5.4.0.1015.14
  linux-image-virtual             5.4.0.37.40
  linux-image-virtual-hwe-20.04   5.4.0.37.40

Please note that the mitigation for CVE-2020-0543 requires a processor
microcode update to be applied, either from your system manufacturer
or via the intel-microcode package. The kernel update for this issue
provides the ability to disable the mitigation and to report
vulnerability status.

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.