> It would appearat first glance that RSX uses the same technique as PAX.
> Naturally, the PAX and RSX teams should confer to make a definitive
> statement on similarities and differences.

Just for the record, the technique bears no similarity. PAX provides
real, non-executable PAGES on x86 -- RSX remaps the heap segments
outside of the code segment limit.

Sometimes it is a pity there is such a grotesque lack of understanding
of x86 operating system architecture around.
(This is not intendet to be an attack towards anyone, please do not take
this personally. It is just a general observation that a lack of
understanding
can lead to security problems -- see the recent FreeBSD/Solaris patch
concerning GDT descriptors which cost Argus half a fortune :-)

Generally, I have to agree with Crispins statements to a certain degree:
While it is possible to argue that both PAX and RSX are obscurity defenses,
at least PAX can, when properly implemented, stop ALL foreign-code execution
and make sure only code that resides inside the process address space
already
can be executed.

Cheers,
dulliengmx.de

-- 
Machen Sie Ihr Hobby zu Geld bei unserem Partner 1&1!
http://profiseller.de/info/index.php3?ac=OM.PS.PS003K00596T0409a
--
GMX - Die Kommunikationsplattform im Internet.
http://www.gmx.net

• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]