==========================================================================
Ubuntu Security Notice USN-3597-2
March 15, 2018

linux-hwe 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-hwe: Linux hardware enablement (HWE) kernel

Details:

USN-3597-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.10.
This update provides the corresponding updates for the Linux Hardware
Enablement (HWE) kernel from Ubuntu 17.10 for Ubuntu 16.04 LTS.

USNS 3541-2 and 3523-2 provided mitigations for Spectre and Meltdown
(CVE-2017-5715, CVE-2017-5753, CVE-2017-5754) for the i386, amd64,
and ppc64el architectures for Ubuntu 16.04 LTS. This update provides
the corresponding mitigations for the arm64 architecture. Original
advisory details:

 Jann Horn discovered that microprocessors utilizing speculative execution
 and indirect branch prediction may allow unauthorized memory reads via
 sidechannel attacks. This flaw is known as Meltdown. A local attacker could
 use this to expose sensitive information, including kernel memory.
 (CVE-2017-5754)

 Jann Horn discovered that microprocessors utilizing speculative execution
 and branch prediction may allow unauthorized memory reads via sidechannel
 attacks. This flaw is known as Spectre. A local attacker could use this to
 expose sensitive information, including kernel memory. (CVE-2017-5715,
 CVE-2017-5753)

Update instructions:

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

Ubuntu 16.04 LTS:
  linux-image-4.13.0-37-generic   4.13.0-37.42~16.04.1
  linux-image-4.13.0-37-generic-lpae  4.13.0-37.42~16.04.1
  linux-image-4.13.0-37-lowlatency  4.13.0-37.42~16.04.1
  linux-image-generic-hwe-16.04   4.13.0.37.56
  linux-image-generic-lpae-hwe-16.04  4.13.0.37.56
  linux-image-lowlatency-hwe-16.04  4.13.0.37.56

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-3597-2,
  https://usn.ubuntu.com/usn/usn-3597-1,
  https://usn.ubuntu.com/usn/usn-3523-2,
  https://usn.ubuntu.com/usn/usn-3541-2,
  CVE-2017-5715, CVE-2017-5753, CVE-2017-5754

Package Information:
  https://launchpad.net/ubuntu/+source/linux-hwe/4.13.0-37.42~16.04.1