Subject: Re: security sysctl? (was: r/o filesystem restrictions for firewall?)
To: None <firstname.lastname@example.org, email@example.com>
From: Thor Lancelot Simon <firstname.lastname@example.org>
Date: 10/25/2000 23:09:51
On Wed, Oct 25, 2000 at 09:14:11PM -0400, email@example.com wrote:
> Does securelevel 2 prevent you from mounting any new devices as well?
> i.e. can I vnconfig and mount that file?
You know, this discussion is rather frustrating to me because all of the
relevant details are pretty well documented. I quote the init(8) manual
2 Highly secure mode - same as secure mode, plus disks are always
read-only whether mounted or not, new disks may not be mounted, and
existing mounts may only be downgraded from read-write to read-on-
ly. This level precludes tampering with filesystems by unmounting
them, but also inhibits running newfs(8) while the system is multi-
The settimeofday(2) system call can only advance the time.
The state of ipf(8) (the in-kernel IP filtering facility) may not
Users may not change the per-process core name template format, on-
ly the default can be changed.
Downgrading from highly secure mode to insecure mode (that is, to
single-user mode) always requires the root password to be entered
on the console, whether the console is marked as 'secure' in
/etc/ttys or not.