Ubuntu 18.04 LTS: USN-4094-1 Critical Kernel DoS Issues

ubuntu

August 13, 2019

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

- linux-gke-4.15: Linux kernel for Google Container Engine (GKE) systems

- linux-kvm: Linux kernel for cloud environments

- linux-oem: Linux kernel for OEM processors- linux-oracle: Linux kernel for Oracle Cloud systems

- linux-raspi2: Linux kernel for Raspberry Pi 2

- linux-snapdragon: Linux kernel for Snapdragon processors- linux-azure: Linux kernel for Microsoft Azure Cloud systems

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

Details:

It was discovered that the alarmtimer implementation in the Linux kernel

contained an integer overflow vulnerability. A local attacker could use

this to cause a denial of service. (CVE-2018-13053)

Wen Xu discovered that the XFS filesystem implementation in the Linux

kernel did not properly track inode validations. An attacker could use this

to construct a malicious XFS image...

Read the Full Advisory

Topics Covered

security advisory denial of service kernel integer overflow ubuntu file system linux

Update Instructions

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

Ubuntu 18.04 LTS:
  linux-image-4.15.0-1021-oracle  4.15.0-1021.23
  linux-image-4.15.0-1040-gcp     4.15.0-1040.42
  linux-image-4.15.0-1040-gke     4.15.0-1040.42
  linux-image-4.15.0-1042-kvm     4.15.0-1042.42
  linux-image-4.15.0-1043-raspi2  4.15.0-1043.46
  linux-image-4.15.0-1050-oem     4.15.0-1050.57
  linux-image-4.15.0-1060-snapdragon  4.15.0-1060.66
  linux-image-4.15.0-58-generic   4.15.0-58.64
  linux-image-4.15.0-58-generic-lpae  4.15.0-58.64
  linux-image-4.15.0-58-lowlatency  4.15.0-58.64
  linux-image-gcp                 4.15.0.1040.42
  linux-image-generic             4.15.0.58.60
  linux-image-generic-lpae        4.15.0.58.60
  linux-image-gke                 4.15.0.1040.43
  linux-image-gke-4.15            4.15.0.1040.43
  linux-image-kvm                 4.15.0.1042.42
  linux-image-lowlatency          4.15.0.58.60
  linux-image-oem                 4.15.0.1050.54
  linux-image-oracle              4.15.0.1021.24
  linux-image-powerpc-e500mc      4.15.0.58.60
  linux-image-powerpc-smp         4.15.0.58.60
  linux-image-powerpc64-emb       4.15.0.58.60
  linux-image-powerpc64-smp       4.15.0.58.60
  linux-image-raspi2              4.15.0.1043.41
  linux-image-snapdragon          4.15.0.1060.63
  linux-image-virtual             4.15.0.58.60

Ubuntu 16.04 LTS:
  linux-image-4.15.0-1021-oracle  4.15.0-1021.23~16.04.1
  linux-image-4.15.0-1040-gcp     4.15.0-1040.42~16.04.1
  linux-image-4.15.0-1055-azure   4.15.0-1055.60
  linux-image-4.15.0-58-generic   4.15.0-58.64~16.04.1
  linux-image-4.15.0-58-generic-lpae  4.15.0-58.64~16.04.1
  linux-image-4.15.0-58-lowlatency  4.15.0-58.64~16.04.1
  linux-image-azure               4.15.0.1055.58
  linux-image-gcp                 4.15.0.1040.54
  linux-image-generic-hwe-16.04   4.15.0.58.79
  linux-image-generic-lpae-hwe-16.04  4.15.0.58.79
  linux-image-gke                 4.15.0.1040.54
  linux-image-lowlatency-hwe-16.04  4.15.0.58.79
  linux-image-oem                 4.15.0.58.79
  linux-image-oracle              4.15.0.1021.15
  linux-image-virtual-hwe-16.04   4.15.0.58.79

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.