[lug] Module support (kernel compile)

[rm at mamma.varadinet.de]

On Thu, Aug 10, 2000 at 11:19:25PM -0400, John Starkey wrote:
> Ok. So if I check yes to the modules session that means (only) that i can
> load them and will know they are loaded with the lsmod command. Or do some
> of the not show up. I'm speaking in general regarding any modulable (is
> that even a word) question in make config.

Ah, i see, you're talking about the modules section in the 'make config'
(funny, this is what i'm staring at right now). This means that the kernel
supports loadable modules ...

> And if I conpile everything in, then can I add things later? I may be
> answering my own question (if I understand myself correctly :} ). I'm
> gathering (from myself) that modules are basically there so they "load on
> demand" without having to recompile. 

... yes, as long as you selected the loadable module support. 
> 
> I know this is a really big question and the answer could probably take up
> a book, but.... what makes them a risk?? 

Well, because from within a module you can change every aspect of the kernel.
For example you can change system functions. As a hacker/cracker it's possible
to redifine some of the virtual file system functions so that the hacker tools
won't show up any more, or one could make certain programs/network connections
'invisible'. This is actually pretty easy. (Of course one needs to be root
to load a module but in certain circumstances not having module support adds
an extra layer of security to the box. Not that you would often need this or
that you should rely on it).


 Ralf