Re: disabling Intel PSN

sinster@balltech.net
Mon, 20 Dec 1999 08:28:00 -0800 (PST)


Sprach nil <laredo@stradis.com>:
> > It has nothing to do with whether or not we want the end user to be able
> > to use the PSN, it's about the ability of vendors to force users thta
> > don't want to to use the PSN.
>
> Well to summarize: The kernel should not dictate policy.
> That's the end of that.
[...]
> in that network support PSN). The kernel should never dictate policy. If
> someone wants to hang himself in the opinion of someone else, it should
> let him.

The kernel should not have a feature that is not used on the system. This
is a basic principle of both information security and computer security:
if you don't use something, disable it.

This is one (I'd claim the main) reason why the ability to disable
(for instance) the networking stack in the kernel at compile time is
so useful: there is no way for that kernel to do networking no matter
how the boot gets tweaked.

> There are no checks in the kernel for unlink of / or /lib, nor should
> there be.

Actually, there is for /. In kernel version 2.2.13 (the version I'm currently
running, mostly because I haven't had time to upgrade), in fs/namei.c,
lines 514 and 515 (in a utility function called may_delete()... gee,
I wonder what that does?):
if (IS_ROOT(victim))
return -EBUSY;
So you see, there _is_ a check in the kernel that prevents you from
deleting the root directory.

-- 
Jon Paul Nollmann ne' Darren Senn                      sinster@balltech.net
Unsolicited commercial email will be archived at $1/byte/day.
Oh, yes. I'm just a laborer in the vineyard, near the 2A vine.  Others can
tend 1A, 5A... I sure wish somebody would volunteer to take care of 9A and
10A, though. Lot of weeds growing in there.                 Woodchuck, 1999

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