Re: [RFC] prevention of syscalls from writable segments, breaking

Mark Zealey (
Wed, 3 Jan 2001 22:39:39 +0000 (GMT)

On Wed, 3 Jan 2001, Alexander Viro wrote:

> On Wed, 3 Jan 2001, Dan Hollis wrote:
> > On Wed, 3 Jan 2001, Alexander Viro wrote:
> > > On Wed, 3 Jan 2001, Dan Aloni wrote:
> > > > without breaking anything. It also reports of such calls by using printk.
> > > Get real.
> >
> > Why do you always have to be insulting alex? Sheesh.
> Sigh... Not intended to be an insult. Plain and simple advice. Idea is
> broken for absolutely obvious reasons (namely, every real-life program

This doesnt stop syscalls, only syscalls from writable areas.

> contains at least one syscall that it _can_ execute). Expecting _any_
> part of userland to be rewritten into the form that would not have
> such places (i.e. all IO is done by trusted processes that poll
> memory areas shared with the programs needing said IO, exit is done
> either by explicit kill() from another process or by dumping core, signals
> are done by putting request into shared area and letting a trusted process
> do the thing, etc.) warrants such suggestion, doesn't it? If somebody
> seriously believes that it can be done (and that's the only way how this
> patch could give any protection)... Well, scratch "get real", I've got a
> nice bridge for sale.

That's a bit OTT, no? ;)



Mark Zealey (aka JALH on #zealos and many more)

UL++++$ (GCM/GCS/GS/GM)GUG! dpu? s-:-@ a15! C+++>$ P++$>+++@ L+++>+++++$ !E---? W+++>$ N++@>+ o->+ w--- !M--? !V--? PS- PE--@ !PGP----? r++ !t---?@ !X---? !R- b+ !DI---? e->+++++ h+++*! y-


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