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  1. 22 Mar, 2017 1 commit
  3. 20 Mar, 2017 9 commits
  5. 07 Mar, 2017 1 commit
  7. 27 Feb, 2017 1 commit
  9. 27 Jan, 2017 1 commit
    • Make lxc-start-ephemeral Python 3.2-compatible · 70cd3b8f
      Colin Watson authored 
      On Ubuntu 12.04 LTS with Python 3.2, `lxc-start-ephemeral` breaks as
follows:

    Traceback (most recent call last):
      File "/usr/bin/lxc-start-ephemeral", line 371, in attach_as_user
      File "/usr/lib/python3.2/subprocess.py", line 515, in check_output
      File "/usr/lib/python3.2/subprocess.py", line 732, in __init__
    LookupError: unknown encoding: ANSI_X3.4-1968

This is because `universal_newlines=True` causes `subprocess` to use
`io.TextIOWrapper`, and in versions of Python earlier than 3.3 that
fetched the preferred encoding using `locale.getpreferredencoding()`
rather than `locale.getpreferredencoding(False)`, thereby changing the
locale and causing codecs to be reloaded.  However, `attach_as_user`
runs inside the container and thus can't rely on having access to the
same Python standard library on disk.

The workaround is to decode by hand instead, avoiding the temporary
change of locale.
Signed-off-by: 's avatarColin Watson <cjwatson@ubuntu.com>
  11. 23 Jan, 2017 1 commit
  13. 03 Jan, 2017 4 commits
  15. 15 Dec, 2016 4 commits
  17. 09 Dec, 2016 1 commit
  19. 08 Dec, 2016 3 commits
  21. 01 Dec, 2016 3 commits
  23. 23 Nov, 2016 2 commits
    • change version to 1.0.9 in configure.ac · 7b483176
      Stéphane Graber authored 
      Signed-off-by: 's avatarStéphane Graber <stgraber@ubuntu.com>
    • attach: do not send procfd to attached process · 9f27a410
      Christian Brauner authored 
      So far, we opened a file descriptor refering to proc on the host inside the
host namespace and handed that fd to the attached process in
attach_child_main(). This was done to ensure that LSM labels were correctly
setup. However, by exploiting a potential kernel bug, ptrace could be used to
prevent the file descriptor from being closed which in turn could be used by an
unprivileged container to gain access to the host namespace. Aside from this
needing an upstream kernel fix, we should make sure that we don't pass the fd
for proc itself to the attached process. However, we cannot completely prevent
this, as the attached process needs to be able to change its apparmor profile
by writing to /proc/self/attr/exec or /proc/self/attr/current. To minimize the
attack surface, we only send the fd for /proc/self/attr/exec or
/proc/self/attr/current to the attached process. To do this we introduce a
little more IPC between the child and parent:

	 * IPC mechanism: (X is receiver)
	 *   initial process        intermediate          attached
	 *        X           <---  send pid of
	 *                          attached proc,
	 *                          then exit
	 *    send 0 ------------------------------------>    X
	 *                                              [do initialization]
	 *        X  <------------------------------------  send 1
	 *   [add to cgroup, ...]
	 *    send 2 ------------------------------------>    X
	 *						[set LXC_ATTACH_NO_NEW_PRIVS]
	 *        X  <------------------------------------  send 3
	 *   [open LSM label fd]
	 *    send 4 ------------------------------------>    X
	 *   						[set LSM label]
	 *   close socket                                 close socket
	 *                                                run program

The attached child tells the parent when it is ready to have its LSM labels set
up. The parent then opens an approriate fd for the child PID to
/proc/<pid>/attr/exec or /proc/<pid>/attr/current and sends it via SCM_RIGHTS
to the child. The child can then set its LSM laben. Both sides then close the
socket fds and the child execs the requested process.
Signed-off-by: 's avatarChristian Brauner <christian.brauner@canonical.com>
  25. 22 Nov, 2016 2 commits
  27. 18 Nov, 2016 7 commits