==========================================================================
Ubuntu Security Notice USN-3847-2
December 20, 2018

linux-hwe, linux-aws-hwe, linux-azure, linux-gcp vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-aws-hwe: Linux kernel for Amazon Web Services (AWS-HWE) systems
- linux-azure: Linux kernel for Microsoft Azure Cloud systems
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
- linux-hwe: Linux hardware enablement (HWE) kernel

Details:

USN-3847-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04
LTS. This update provides the corresponding updates for the Linux
Hardware Enablement (HWE) kernel from Ubuntu 18.04 LTS for Ubuntu
16.04 LTS.

It was discovered that a race condition existed in the raw MIDI driver for
the Linux kernel, leading to a double free vulnerability. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2018-10902)

It was discovered that an integer overrun vulnerability existed in the
POSIX timers implementation in the Linux kernel. A local attacker could use
this to cause a denial of service. (CVE-2018-12896)

Noam Rathaus discovered that a use-after-free vulnerability existed in the
Infiniband implementation in the Linux kernel. An attacker could use this
to cause a denial of service (system crash). (CVE-2018-14734)

It was discovered that the YUREX USB device driver for the Linux kernel did
not properly restrict user space reads or writes. A physically proximate
attacker could use this to cause a denial of service (system crash) or
possibly execute arbitrary code. (CVE-2018-16276)

It was discovered that the BPF verifier in the Linux kernel did not
correctly compute numeric bounds in some situations. A local attacker could
use this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2018-18445)

Kanda Motohiro discovered that writing extended attributes to an XFS file
system in the Linux kernel in certain situations could cause an error
condition to occur. A local attacker could use this to cause a denial of
service. (CVE-2018-18690)

It was discovered that an integer overflow vulnerability existed in the
CDROM driver of the Linux kernel. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2018-18710)

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.15.0-1026-gcp     4.15.0-1026.27~16.04.1
  linux-image-4.15.0-1031-aws     4.15.0-1031.33~16.04.1
  linux-image-4.15.0-1036-azure   4.15.0-1036.38~16.04.1
  linux-image-4.15.0-43-generic   4.15.0-43.46~16.04.1
  linux-image-4.15.0-43-generic-lpae  4.15.0-43.46~16.04.1
  linux-image-4.15.0-43-lowlatency  4.15.0-43.46~16.04.1
  linux-image-aws-hwe             4.15.0.1031.32
  linux-image-azure               4.15.0.1036.41
  linux-image-gcp                 4.15.0.1026.40
  linux-image-generic-hwe-16.04   4.15.0.43.64
  linux-image-generic-lpae-hwe-16.04  4.15.0.43.64
  linux-image-gke                 4.15.0.1026.40
  linux-image-lowlatency-hwe-16.04  4.15.0.43.64

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.

References:
  https://usn.ubuntu.com/usn/usn-3847-2
  https://usn.ubuntu.com/usn/usn-3847-1
  CVE-2018-10902, CVE-2018-12896, CVE-2018-14734, CVE-2018-16276,
  CVE-2018-18445, CVE-2018-18690, CVE-2018-18710

Package Information:
  https://launchpad.net/ubuntu/+source/linux-aws-hwe/4.15.0-1031.33~16.04.1
  https://launchpad.net/ubuntu/+source/linux-azure/4.15.0-1036.38~16.04.1
  https://launchpad.net/ubuntu/+source/linux-gcp/4.15.0-1026.27~16.04.1
  https://launchpad.net/ubuntu/+source/linux-hwe/4.15.0-43.46~16.04.1