Re: Users locking memory using futexes
Rusty Russell (rusty@rustcorp.com.au)
Wed, 13 Nov 2002 04:17:47 +1100
In message <20021112034648.GA11766@bjl1.asuk.net> you write:
> Perez-Gonzalez, Inaky wrote:
> > [...] each time you lock a futex you are pinning the containing page
> > into physical memory, that would cause that if you have, for
> > example, 4000 futexes locked in 4000 different pages, there is going
> > to be 4 MB of memory locked in [...]
>
> Ouch! It looks to me like userspace can use FUTEX_FD to lock many
> pages of memory, achieving the same as mlock() but without the
> resource checks.
>
> Denial of service attack?
See "pipe".
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
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