Re: [RFC] ext2 and ext3 block reservations can be bypassed

[Jesse Pollard <pollard@tomcat.admin.navo.hpc.mil>]

> 
> A second method was proposed as well - create a file with a hole in it,
> map it, then dirty the pages in the hole and exit.  This would not
> require suid.

Actually, the allocation that fills the partition (and goes one over)
should fail. Even if that is only adding a block to the hole, it should
fail. Now if it DOES continue then you have found a bug since it
shouldn't do that.

> This is basically a documentation issue, unless someone wants to go fix
> it.  I wouldn't bother myself - it's ext[23] only and not really very
> useful.
> 
> The basic problem is this: the documentation states "This is intended to
> allow for the system to continue functioning even if non-priveleged
> users fill up all the space available to them."  This states that it's a
> security feature.  It does not work as intended - all users are
> privileged to do this - so the documentation should be updated.

There is nothing wrong with the documentation. Though it could have
additions to more clearly explain why. The feature can already be disabled.

-------------------------------------------------------------------------
Jesse I Pollard, II
Email: pollard@navo.hpc.mil

Any opinions expressed are solely my own.