Bug#739593: unshare -m aka unshare(CLONE_NEWNS) mounts are visible globally

[Christoph Berg <christoph.berg@credativ.de>]

Source: linux
Version: 3.12.9-1
Severity: important

Mounts done in a unshare(CLONE_NEWNS) or unshare -m environment are
globally visible, and are not automatically removed once the process
exits:

$ mount | grep foobar
$ sudo unshare -m -- mount -t tmpfs foobar /tmp
$ mount | grep foobar
foobar on /tmp type tmpfs (rw,relatime)

This system is running systemd 204-6.

-- System Information:
Debian Release: jessie/sid
  APT prefers testing
  APT policy: (700, 'testing'), (150, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.12-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=de_DE.utf8, LC_CTYPE=de_DE.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Christoph
-- 
cb@df7cb.de | http://www.df7cb.de/