Re: Proposal: restrict link(2)

Greg Alexander (galexand@sietch.bloomington.in.us)
Wed, 11 Dec 1996 23:00:01 -0500 (EST)


On Wed, 11 Dec 1996, Hubert Mantel wrote:

> I would not like to have /etc/passwd on the same file system as /tmp. I
> think critical systems should have a really small root partition and
> everything else should reside on separate partitions, so no hard linking
> to the files mentioned is possible.

However, for small code-hackers, who do all sorts of funny things to their
systems, finding a single linux partition with all of the files on it is a
_very_ common thing. security should not be denied to these systems.
However, I don't think that this is necessarily a kernel issue.
If compatability is hoped to be maintained with more "standard" flavors
then the commands should probably continue to work basically the same. It
presents a problem that can and should be easily solved in userspace.
Having the kernel take care of everything adds to all sorts of
portability/security problems on other platforms. Even the way that some
of the includes include other stuff automatically for me has proven to be
a pain in the butt when trying to port to SunOS (am I seeing funny
systems, or is every SunOS system's include files really messed up?).
Being able to assume that there are no hardlinks in /tmp that shouldn't be
there is not an assumption that I think programs should be able to make.

Greg Alexander
http://www.cia-g.com/~sietch/