Ubuntu 20.04 LTS: USN-4984-1 Critical: Linux Kernel Security Issues

ubuntu

June 4, 2021

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

- linux-hwe-5.8: Linux hardware enablement (HWE) kernel

Details:

Jan Beulich discovered that the Xen netback backend in the Linux kernel did

not properly handle certain error conditions under paravirtualization. An

attacker in a guest VM could possibly use this to cause a denial of service

(host domain crash). (CVE-2021-28038)

It was discovered that the Realtek RTL8188EU Wireless device driver in the

Linux kernel did not properly validate ssid lengths in some situations. An

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

(CVE-2021-28660)

It was ...

Read the Full Advisory

Topics Covered

security advisory denial of service critical Ubuntu kernel system crash Linux

Update Instructions

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

Ubuntu 20.10:
  linux-image-5.8.0-1028-kvm      5.8.0-1028.30
  linux-image-5.8.0-1031-oracle   5.8.0-1031.32
  linux-image-5.8.0-1032-gcp      5.8.0-1032.34
  linux-image-5.8.0-1033-azure    5.8.0-1033.35
  linux-image-5.8.0-1035-aws      5.8.0-1035.37
  linux-image-5.8.0-55-generic    5.8.0-55.62
  linux-image-5.8.0-55-generic-64k  5.8.0-55.62
  linux-image-5.8.0-55-generic-lpae  5.8.0-55.62
  linux-image-5.8.0-55-lowlatency  5.8.0-55.62
  linux-image-aws                 5.8.0.1035.37
  linux-image-azure               5.8.0.1033.33
  linux-image-gcp                 5.8.0.1032.32
  linux-image-generic             5.8.0.55.60
  linux-image-generic-64k         5.8.0.55.60
  linux-image-generic-lpae        5.8.0.55.60
  linux-image-gke                 5.8.0.1032.32
  linux-image-kvm                 5.8.0.1028.30
  linux-image-lowlatency          5.8.0.55.60
  linux-image-oracle              5.8.0.1031.30
  linux-image-virtual             5.8.0.55.60

Ubuntu 20.04 LTS:
  linux-image-5.8.0-55-generic    5.8.0-55.62~20.04.1
  linux-image-5.8.0-55-generic-64k  5.8.0-55.62~20.04.1
  linux-image-5.8.0-55-generic-lpae  5.8.0-55.62~20.04.1
  linux-image-5.8.0-55-lowlatency  5.8.0-55.62~20.04.1
  linux-image-generic-64k-hwe-20.04  5.8.0.55.62~20.04.39
  linux-image-generic-hwe-20.04   5.8.0.55.62~20.04.39
  linux-image-generic-lpae-hwe-20.04  5.8.0.55.62~20.04.39
  linux-image-lowlatency-hwe-20.04  5.8.0.55.62~20.04.39
  linux-image-virtual-hwe-20.04   5.8.0.55.62~20.04.39

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.