[PATCH 1/4] data: Add systemd-tmpfiles configuration to create

[PATCH 1/4] data: Add systemd-tmpfiles configuration to create

Backport of the following upstream patch:
From 6226cdc57052f4b7057d92f2e549aa169e35cd2d Mon Sep 17 00:00:00 2001

private tmp dir
Backport of the following upstream patch:
From 6226cdc57052f4b7057d92f2e549aa169e35cd2d Mon Sep 17 00:00:00 2001
From: Alex Murray <alex.murray@canonical.com>
Date: Thu, 20 Oct 2022 10:28:42 +1030
Subject: [PATCH 1/4] data: Add systemd-tmpfiles configuration to create
 private tmp dir

Use systemd-tmpfiles to create the private tmp mount namespace root
dir (/tmp/snap-private-tmp) on boot as owned by root with restrictive
permissions. We can use this as a known location to then create per-snap
private tmp mount namespace dirs (/tmp/snap-private-tmp/snap.$SNAP_INSTANCE)
etc.

Signed-off-by: Alex Murray <alex.murray@canonical.com>
Gbp-Pq: Topic cve20223328
Gbp-Pq: Name 0016-cve-2022-3328-1.patch