linux-lts-xenial, linux-aws vulnerabilities

USN-3540-1 addressed vulnerabilities in the Linux kernel for Ubuntu
16.04 LTS. This update provides the corresponding updates for the
Linux Hardware Enablement (HWE) kernel from Ubuntu 16.04 LTS for
Ubuntu 14.04 LTS.

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. This update provides mitigations for the
i386 (CVE-2017-5753 only), amd64, ppc64el, and s390x architectures.
(CVE-2017-5715, CVE-2017-5753)

USN-3522-2 mitigated CVE-2017-5754 (Meltdown) for the amd64
architecture in the Linux Hardware Enablement (HWE) kernel from Ubuntu
16.04 LTS for Ubuntu 14.04 LTS. This update provides the corresponding
mitigations for the ppc64el 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)