Re: mount_nullfs inside a jail

From: Pawel Jakub Dawidek <pjd_at_FreeBSD.org>
Date: Mon, 23 Jul 2007 15:33:33 +0200
On Sun, Jul 22, 2007 at 04:18:06AM +0400, Boris Samorodov wrote:
> Hi!
> 
> 
> Is it possible to use mount_nullfs inside a jail?
> 
> With amd64-current:
> -----
> # sysctl security.jail
> security.jail.jailed: 1
> security.jail.mount_allowed: 1
> security.jail.chflags_allowed: 1
> security.jail.allow_raw_sockets: 0
> security.jail.enforce_statfs: 2
> security.jail.sysvipc_allowed: 1
> security.jail.socket_unixiproute_only: 1
> security.jail.set_hostname_allowed: 1
> # mount_nullfs /usr/ports /mnt
> mount_nullfs: Operation not permitted
> -----

It is not possible. From jail(8):

     security.jail.mount_allowed
          This MIB entry determines if a privileged user inside a jail will be
          able to mount and unmount file system types marked as jail-friendly.
          The lsvfs(1) command can be used to find file system types available
          for mount from within a jail.  This functionality is disabled by
          default, but can be enabled by setting this MIB entry to 1.

	# lsvfs
	Filesystem                        Refs Flags
	-------------------------------- ----- ---------------
	zfs                                  0 jail
	nullfs                               0 loopback

As you can see, nullfs doesn't have 'jail' flag. The only jail-friendly
file system currently is ZFS. Nullfs is a good candidate for a
jail-friendly file system, but is not marked as such yet.

-- 
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd_at_FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!

Received on Mon Jul 23 2007 - 12:02:56 UTC

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