Re: [PATCH] Undo some of the pseudo-security madness

[Arjan van de Ven <arjan@infradead.org>]

On Sat, 2007-01-20 at 17:37 +0300, Samium Gromoff wrote:
> This patch removes the dropping of ADDR_NO_RANDOMIZE upon execution of setuid
> binaries.
> 
> Why? The answer consists of two parts:
> 
> Firstly, there are valid applications which need an unadulterated memory map.
> Some of those which do their memory management, like lisp systems (like SBCL).
> They try to achieve this by setting ADDR_NO_RANDOMIZE and reexecuting themselves.

this is a ... funny way of achieving this

if an application for some reason wants some fixed address for a piece
of memory there are other ways to do that.... (but to some degree all
apps that can't take randomization broken; for example a glibc upgrade
on a system will also move the address space around by virtue of being
bigger or smaller etc etc)


> [1]. See the excellent, 'Hackers Hut' by Andries Brouwer, which describes
> how AS randomisation can be got around by the means of linux-gate.so.1

got a URL to this? If this is exploiting the fact that the vdso is at a
fixed spot... it's no longer the case since quite a while.


-- 
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

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