Ubuntu 16.04 LTS: USN-3821-1 Critical: Kernel Denial Of Service Threats

ubuntu

November 14, 2018

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-kvm: Linux kernel for cloud environments

- linux-raspi2: Linux kernel for Raspberry Pi 2

- linux-snapdragon: Linux kernel for Snapdragon processors

Details:

Wen Xu discovered that the ext4 filesystem implementation in the Linux

kernel did not properly ensure that xattr information remained in inode

bodies. An attacker could use this to construct a malicious ext4 image

that, when mounted, could cause a denial of service (system crash).

(CVE-2018-10880)

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 f2fs filesystem implementation in the Linux

kernel did not properly validate metadata. An attacker could use this to

construct a malicious f...

Read the Full Advisory

Topics Covered

security advisory denial of service critical Ubuntu kernel information exposure system crash

Update Instructions

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1037-kvm      4.4.0-1037.43
  linux-image-4.4.0-1072-aws      4.4.0-1072.82
  linux-image-4.4.0-1100-raspi2   4.4.0-1100.108
  linux-image-4.4.0-1104-snapdragon  4.4.0-1104.109
  linux-image-4.4.0-139-generic   4.4.0-139.165
  linux-image-4.4.0-139-generic-lpae  4.4.0-139.165
  linux-image-4.4.0-139-lowlatency  4.4.0-139.165
  linux-image-4.4.0-139-powerpc-e500mc  4.4.0-139.165
  linux-image-4.4.0-139-powerpc-smp  4.4.0-139.165
  linux-image-4.4.0-139-powerpc64-emb  4.4.0-139.165
  linux-image-4.4.0-139-powerpc64-smp  4.4.0-139.165
  linux-image-aws                 4.4.0.1072.74
  linux-image-generic             4.4.0.139.145
  linux-image-generic-lpae        4.4.0.139.145
  linux-image-kvm                 4.4.0.1037.36
  linux-image-lowlatency          4.4.0.139.145
  linux-image-powerpc-e500mc      4.4.0.139.145
  linux-image-powerpc-smp         4.4.0.139.145
  linux-image-powerpc64-emb       4.4.0.139.145
  linux-image-powerpc64-smp       4.4.0.139.145
  linux-image-raspi2              4.4.0.1100.100
  linux-image-snapdragon          4.4.0.1104.96

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.