Ubuntu 16.04 LTS: USN-4116-1 Critical: Kernel Denial of Service

ubuntu

September 2, 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-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:

It was discovered that a use-after-free error existed in the block layer

subsystem of the Linux kernel when certain failure conditions occurred. A

local attacker could possibly use this to cause a denial of service (system

crash) or possibly execute arbitrary code. (CVE-2018-20856)

Amit Klein and Benny Pinkas discovered that the Linux kernel did not

sufficiently randomize IP ID values generated for connectionless networking

protocols. A remote attacker could use this to track particular Linux

devices. (CVE-2019-10638)

Praveen Pandey discovered that the Linux kernel did not properly validate

sent signals in some situations on PowerPC systems with transacti...

Read the Full Advisory

Topics Covered

security advisory DoS Ubuntu kernel AWS buffer overread exec code

Update Instructions

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1056-kvm      4.4.0-1056.63
  linux-image-4.4.0-1092-aws      4.4.0-1092.103
  linux-image-4.4.0-1120-raspi2   4.4.0-1120.129
  linux-image-4.4.0-1124-snapdragon  4.4.0-1124.130
  linux-image-4.4.0-161-generic   4.4.0-161.189
  linux-image-4.4.0-161-generic-lpae  4.4.0-161.189
  linux-image-4.4.0-161-lowlatency  4.4.0-161.189
  linux-image-4.4.0-161-powerpc-e500mc  4.4.0-161.189
  linux-image-4.4.0-161-powerpc-smp  4.4.0-161.189
  linux-image-4.4.0-161-powerpc64-emb  4.4.0-161.189
  linux-image-4.4.0-161-powerpc64-smp  4.4.0-161.189
  linux-image-aws                 4.4.0.1092.96
  linux-image-generic             4.4.0.161.169
  linux-image-generic-lpae        4.4.0.161.169
  linux-image-kvm                 4.4.0.1056.56
  linux-image-lowlatency          4.4.0.161.169
  linux-image-powerpc-e500mc      4.4.0.161.169
  linux-image-powerpc-smp         4.4.0.161.169
  linux-image-powerpc64-emb       4.4.0.161.169
  linux-image-powerpc64-smp       4.4.0.161.169
  linux-image-raspi2              4.4.0.1120.120
  linux-image-snapdragon          4.4.0.1124.116
  linux-image-virtual             4.4.0.161.169

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.