Ubuntu 16.04 LTS: 4486-1 Critical: Kernel Crash via XFS Filesystem

ubuntu

September 2, 2020

The Linux kernel could be made to crash if it mounted a malicious XFS file system.

Summary

The Linux kernel could be made to crash if it mounted a malicious XFS

file system.

Software Description:

- linux: Linux kernel

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

- linux-kvm: Linux kernel for cloud environments

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

- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty

Details:

Wen Xu discovered that the XFS filesystem implementation in the Linux

kernel did not properly validate meta-data information. An attacker could

use this to construct a malicious xfs image that, when mounted, could cause

a denial of service (system crash).

Topics Covered

security advisory denial of service kernel filesystem issue ubuntu

Update Instructions

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1079-kvm      4.4.0-1079.86
  linux-image-4.4.0-1113-aws      4.4.0-1113.126
  linux-image-4.4.0-1138-raspi2   4.4.0-1138.147
  linux-image-4.4.0-1142-snapdragon  4.4.0-1142.151
  linux-image-4.4.0-189-generic   4.4.0-189.219
  linux-image-4.4.0-189-generic-lpae  4.4.0-189.219
  linux-image-4.4.0-189-lowlatency  4.4.0-189.219
  linux-image-4.4.0-189-powerpc-e500mc  4.4.0-189.219
  linux-image-4.4.0-189-powerpc-smp  4.4.0-189.219
  linux-image-4.4.0-189-powerpc64-emb  4.4.0-189.219
  linux-image-4.4.0-189-powerpc64-smp  4.4.0-189.219
  linux-image-aws                 4.4.0.1113.118
  linux-image-generic             4.4.0.189.195
  linux-image-generic-lpae        4.4.0.189.195
  linux-image-kvm                 4.4.0.1079.77
  linux-image-lowlatency          4.4.0.189.195
  linux-image-powerpc-e500mc      4.4.0.189.195
  linux-image-powerpc-smp         4.4.0.189.195
  linux-image-powerpc64-emb       4.4.0.189.195
  linux-image-powerpc64-smp       4.4.0.189.195
  linux-image-raspi2              4.4.0.1138.138
  linux-image-snapdragon          4.4.0.1142.134
  linux-image-virtual             4.4.0.189.195

Ubuntu 14.04 ESM:
  linux-image-4.4.0-1077-aws      4.4.0-1077.81
  linux-image-4.4.0-189-generic   4.4.0-189.219~14.04.1
  linux-image-4.4.0-189-generic-lpae  4.4.0-189.219~14.04.1
  linux-image-4.4.0-189-lowlatency  4.4.0-189.219~14.04.1
  linux-image-4.4.0-189-powerpc-e500mc  4.4.0-189.219~14.04.1
  linux-image-4.4.0-189-powerpc-smp  4.4.0-189.219~14.04.1
  linux-image-4.4.0-189-powerpc64-emb  4.4.0-189.219~14.04.1
  linux-image-4.4.0-189-powerpc64-smp  4.4.0-189.219~14.04.1
  linux-image-aws                 4.4.0.1077.74
  linux-image-generic-lpae-lts-xenial  4.4.0.189.165
  linux-image-generic-lts-xenial  4.4.0.189.165
  linux-image-lowlatency-lts-xenial  4.4.0.189.165
  linux-image-powerpc-e500mc-lts-xenial  4.4.0.189.165
  linux-image-powerpc-smp-lts-xenial  4.4.0.189.165
  linux-image-powerpc64-emb-lts-xenial  4.4.0.189.165
  linux-image-powerpc64-smp-lts-xenial  4.4.0.189.165
  linux-image-virtual-lts-xenial  4.4.0.189.165

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.