Bug#903025: systemd-run -p IPAddressDeny=any does not stop network in systemd-nspawn

[root]

Package: systemd-container
Version: 239-4
Severity: important
Tags: security

Dear Maintainer,

systemd-run -t -p "IPAddressDeny=any" ping -c 1 192.168.1.1 normally generates
ping: sendmsg: Operation not permitted

When we run the above command in systemd-nspawn -b -M some-machine,
it generates
64 bytes from 192.168.1.1: icmp_seq=1 ttl=255 time=0.305 ms

By the same reason, "IPAddressDeny=any" has no effect in the systemd
service configuration files inside a systemd container.
The protection mechanism by "IPAddressDeny=any" does not work
at all inside a systemd container.
I saw this failure of protection as potentially dangerous,
and gave "important" severity and "security" tag.

On the host linux the versions of systemd and systemd-nspawn are
both 239-4. On the guest linux the version of systemd is also 239-4.

Best regards,
Ryutaroh

-- System Information:
Debian Release: 9.4
  APT prefers stable
  APT policy: (990, 'stable'), (500, 'stable-updates'), (500, 'unstable'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.16.0-0.bpo.2-amd64 (SMP w/8 CPU cores)
Locale: LANG=ja_JP.UTF-8, LC_CTYPE=ja_JP.UTF-8 (charmap=UTF-8), LANGUAGE=ja_JP.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages systemd-container depends on:
ii  dbus             1.12.8-3
ii  libacl1          2.2.52-3+b1
ii  libbz2-1.0       1.0.6-8.1
ii  libc6            2.27-3
ii  libcurl3-gnutls  7.52.1-5+deb9u6
ii  libgcrypt20      1.8.3-1
ii  liblzma5         5.2.2-1.2+b1
ii  libseccomp2      2.3.1-2.1
ii  libselinux1      2.6-3+b3
ii  systemd          239-4
ii  zlib1g           1:1.2.8.dfsg-5

Versions of packages systemd-container recommends:
pn  btrfs-progs        <none>
pn  libnss-mymachines  <none>

systemd-container suggests no packages.

-- no debconf information