Re: [PATCH v2] futex: mark get_robust_list as deprecated

From: Cyrill Gorcunov
Date: Fri Aug 03 2012 - 07:27:43 EST


On Fri, Aug 03, 2012 at 01:19:24PM +0200, richard -rw- weinberger wrote:
> >>
> >> CRIU folks, how do you deal with futex robust lists?
> >
> > Well, I believe we were over-optimistic in claiming that we don't need this
> > syscall (to be fair I think we simply yet not faced the problem Eric points).
> > So we need some way to fetch this address and set it back. If get_robust_list
> > get deprecated maybe we could print it out in /proc/pid/stat or something?
>
> Kees, you said get_robust_list() can be used to bypass ASLR.
> How? What makes it worse than /proc/pid/maps?
>
> If the robust list address itself is bad, removing get_robust_list()
> and putting the information into /proc is useless.

Look, the /proc entry might check for some CAP and do not allow
a regular user to fetch this address.

Cyrill
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