Re: [gentoo-hardened] Exploitable Weakness: Shared Memory

[Joshua Brindle]

Dan Margolis wrote:
>
> It's entirely possible to set up a restricted system which only allows
> certain kinds of access, and limit that access to the execution of
> specific programs, even if this involves whitelisting if necessary. TPE
> (the way GRSec does it, at least) allows one to whitelist a directory,
> which is (or should be) effective. If you can tell me how it's not, I'd
> appreciate it (not that I use such measures on any of my own machines,
> but I am curious).
>
>
How about running 'untrusted' code through any interpreter in your trusted path, 
  are you going to somehow prevent interpreters from reading anything in 
non-root owned directories? This is a slippery slope and quickly approaches the 
need for MAC. I repeat, TPE is a broken model and should not be relied on for 
anything.
>
>>>It isn't a bug in the documentation.
>
>
>
> It is either a bug in the documentation to be incomplete when
> recommending noexec, or, as you say, perhaps a bug in the documentation
> to recommend noexec at all. Either way, it's internally inconsistent,
> which means it's a bug (i.e. there's no reason to recommend
> nosuid/noexec for only some partitions it can be used on, whether or not
> those flags are even useful).
>

We should not recomment noexec, noexec does nothing at all.


Joshua

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