Ubuntu 16.04 LTS: USN-4076-1 Critical Denial of Service Issues

ubuntu

July 25, 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

Details:

It was discovered that a race condition existed in the Serial Attached SCSI

(SAS) implementation in the Linux kernel. A local attacker could possibly

use this to cause a denial of service (system crash) or execute arbitrary

code. (CVE-2018-20836)

It was discovered that the ext4 file system implementation in the Linux

kernel did not properly zero out memory in some situations. A local

attacker could use this to expose sensitive information (kernel memory).

(CVE-2019-11833)

It was discovered that the Bluetooth Human Interface Device Protocol (HIDP)

implementation in the Linux kernel did not properly verify strings were

NULL terminated in certain situations. A local attacker could use this to

expose sensitive infor...

Read the Full Advisory

Topics Covered

security advisory denial of service remote code execution Ubuntu kernel information exposure cloud security

Update Instructions

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

Ubuntu 16.04 LTS:
  linux-image-4.4.0-1052-kvm      4.4.0-1052.59
  linux-image-4.4.0-1088-aws      4.4.0-1088.99
  linux-image-4.4.0-1117-raspi2   4.4.0-1117.126
  linux-image-4.4.0-157-generic   4.4.0-157.185
  linux-image-4.4.0-157-generic-lpae  4.4.0-157.185
  linux-image-4.4.0-157-lowlatency  4.4.0-157.185
  linux-image-4.4.0-157-powerpc-e500mc  4.4.0-157.185
  linux-image-4.4.0-157-powerpc-smp  4.4.0-157.185
  linux-image-4.4.0-157-powerpc64-emb  4.4.0-157.185
  linux-image-4.4.0-157-powerpc64-smp  4.4.0-157.185
  linux-image-aws                 4.4.0.1088.91
  linux-image-generic             4.4.0.157.165
  linux-image-generic-lpae        4.4.0.157.165
  linux-image-kvm                 4.4.0.1052.52
  linux-image-lowlatency          4.4.0.157.165
  linux-image-powerpc-e500mc      4.4.0.157.165
  linux-image-powerpc-smp         4.4.0.157.165
  linux-image-powerpc64-emb       4.4.0.157.165
  linux-image-powerpc64-smp       4.4.0.157.165
  linux-image-raspi2              4.4.0.1117.117
  linux-image-virtual             4.4.0.157.165

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.