[BBLISA] Secure, authenticated file serving to untrusted clients

[Tom Metro]

Dean Anderson wrote:
> Michael Sprague wrote:
>> ...couldn't you use something like grsecurity or selinux to prevent
>> even root from doing anything bad to the network attached storage?
> 
> "No, they won't help if root can't be trusted". The reason is that once
> you have kernel loader privilege, you can alter the kernel to circumvent
> whatever security has been added to it...

Your answer may be correct, but I'm not sure it is relevant in the 
context of the original question.

If the original question is about providing access to a file system over 
a network where the remote *clients* don't have a secure and trusted 
root, then obtaining "kernel loader privilege" on the server is not 
likely to happen.

Where SELinux comes into play is if you want to retain some of the 
behaviors you get when you configure NFS to be cooperative with root 
users on the client machines, but want finer grain control over what 
those users can do. In this case you use SELinux to clamp down on what 
the NFS server is capable of doing, and the clients can't bypass that 
security as long as the server isn't breached.

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/