Re: [PATCH v5 9/9] x86-64: Add CONFIG_UNSAFE_VSYSCALLS to feature-removal-schedule

[pageexec]

On 6 Jun 2011 at 16:44, Ingo Molnar wrote:
> * pageexec@xxxxxxxxxxx <pageexec@xxxxxxxxxxx> wrote:
> 
> > > > Seriously. The whole patch series just seems annoying.
> > 
> > what is annoying is your covering up of security fixes on grounds 
> > that you don't want to help script kiddies (a bullshit argument as 
> > it were) but at the same time question proactive security measures 
> > (one can debate the implementation, see my other mail) that would 
> > *actually* prevent the same kiddies from writing textbook exploits.
> 
> You are mixing up several issues here, and rather unfairly so.

but it's very simple logic Ingo. it goes like 'I am not willing to
do A because it would help script kiddies but I'd rather do B that
would help script kiddies'. with A = 'disclose security bugs' and
B = 'keep the last roadblock that prevents full ASLR'.

if someone's that worried about script kiddies as Linus claims to be
(which i always called a BS argument, but let's accept here), he can't
possibly argue for keeping the vsyscall page at a fixed address around,
simple as that.

and it is for security, no other reason, else you'd have to accept a patch
that maps the vdso at a fixed address again or come up with some very
convincing arguments why the vdso must stay randomized but the vsyscall
page is fine at a fixed address (i guess neither is forthcoming but you
guys can act in surprising ways, so i'm not placing any bets ;).

> Firstly, see my other mail, there's an imperfect balance to be
> found between statistical 'proactive' measures and the incentives
> that remove the *real* bugs.

i hope i replied to this already now to your satisfaction else feel free
to elaboarte.

> Secondly, *once* a real security bug has been found the correct 
> action is different from the considerations of proactive measures. 

as i said already, you're mixing up fixing bugs and fighting exploit
techniques. apples vs. oranges.

> How can you possibly draw equivalence between disclosure policies
> and the handling of statistical security measures?

see the simple logic above.

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