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From: riel@surriel.com (Rik van Riel)
To: kernelnewbies@lists.kernelnewbies.org
Subject: How to change page permission from inside the kernel?
Date: Fri, 06 Jul 2018 22:13:02 -0400	[thread overview]
Message-ID: <1530929582.5350.28.camel@surriel.com> (raw)
In-Reply-To: <CAAGnT3YTAfNr5mkVPR1OPHot+ByGy12njihtC6Tco7ee6AUh0Q@mail.gmail.com>

On Fri, 2018-07-06 at 21:29 +0200, Ahmed Soliman wrote:

> > 2) And why from inside the kernel?
> 
> Because this needs to be done from inside KVM.
> 
> Note: I am aware that this won't be effective against rootkits that
> live in userspace, rootkits that target kernel dynamic data, files on
> disk, as well as VMM escapes, but I believe if the attack surface is
> reduced by just a little bit, it is not that bad, so please lets not
> discuss that :P.

It sounds like the only permission you care about is
the permission of the _guest_ writing to that memory,
not the permission of the qemu-kvm userspace program
writing to that memory.

You may be looking at the wrong page mapping to
manipulate.

-- 
All Rights Reversed.
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  parent reply	other threads:[~2018-07-07  2:13 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-06 18:06 How to change page permission from inside the kernel? Ahmed Soliman
2018-07-06 18:42 ` valdis.kletnieks at vt.edu
2018-07-06 19:29   ` Ahmed Soliman
2018-07-06 21:10     ` valdis.kletnieks at vt.edu
     [not found]       ` <CAAGnT3Ymh6EcdaLo=rGR4-oH0nYub8v9VCZaCtppyxxJAmh5Ag@mail.gmail.com>
2018-07-06 21:59         ` Fwd: " Ahmed Soliman
2018-07-06 22:32           ` valdis.kletnieks at vt.edu
2018-07-06 23:31             ` Ahmed Soliman
2018-07-07  2:06               ` valdis.kletnieks at vt.edu
2018-07-07  2:13     ` Rik van Riel [this message]
2018-07-07 11:05       ` Ahmed Soliman
2018-07-06 18:49 ` Ruben Safir

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