[B/D][SRU] Fix for CVE-2019-5108

[Connor Kuehl]

https://people.canonical.com/~ubuntu-security/cve/2019/CVE-2019-5108.html

>From the link above:

    "An exploitable denial-of-service vulnerability exists in the Linux kernel
    prior to mainline 5.3. An attacker could exploit this vulnerability by
    triggering AP to send IAPP location updates for stations before the
    required authentication process has completed. This could lead to different
    denial-of-service scenarios, either by causing CAM table attacks, or by
    leading to traffic flapping if faking already existing clients in other
    nearby APs of the same wireless infrastructure. An attacker can forge
    Authentication and Association Request packets to trigger this
    vulnerability."

This fix is making its way into Xenial via upstream stable update 4.4.211.

Clean cherry pick into Disco. Picked its pre-requisite patch to make it a clean
cherry pick into Bionic which also allows it to have more parity with Xenial as
the pre-requisite patch was also a part of that upstream stable update.