Re: Misc Fixes

Matthias Urlichs (smurf@smurf.noris.de)
Fri, 12 Jul 1996 07:26:50 +0100


In linux.dev.kernel, article <199607101820.LAA08825@netcom.netcom.com>,
robey@netcom.com (Robey Pointer) writes:
>=20
> How about a small kernel function to return the current securelevel v=
alue?
> int get_securelevel();
> Then export THAT to modules.
>=20
The problem is that any truly malicious module can get the address of t=
hat
function, look for the addresss of the securelevel variable, dereferenc=
e
that, and set it to zero.

Duh.

IMHO, securelevel is a stopgap hack until the finer-grained permission =
test
/ ACL stuff is here. "root" can do _anything_ to the system; always cou=
ld,
and always will, until we get rid of that singular root account (eg.,
make susuer() always return false if the securelevel is high enough; bu=
t
that needs the aforementioned stuff in order to work in the real world)=
.

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