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From: Dave Hansen <dave.hansen@intel.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>,
	Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	"Theodore Ts'o" <tytso@mit.edu>, Oleg Nesterov <oleg@redhat.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>
Subject: Re: [RFC][PATCH 1/2] fs proc: make pagemap a privileged interface
Date: Mon, 09 Mar 2015 19:28:22 -0700	[thread overview]
Message-ID: <54FE56C6.7000902@intel.com> (raw)
In-Reply-To: <87h9ttrcpr.fsf@x220.int.ebiederm.org>

On 03/09/2015 04:08 PM, Eric W. Biederman wrote:
> If the concern is to protect against root getting into the kernel the
> "trusted_kernel" snake-oil just compile out the pagemap file.  Nothing
> else is remotely interesting from a mainenance point of view.

The paper I linked to showed one example of how pagemap makes a
user->kernel exploint _easier_.  Note that the authors had another way
of actually doing the exploit when pagemap was not available, but it
required some more trouble than if pagemap was around.

I mentioned the "trusted_kernel" stuff as an aside.  It's really not the
main concern.

  parent reply	other threads:[~2015-03-10  2:28 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20150309204321.AAF412E0@viggo.jf.intel.com>
2015-03-09 21:31 ` [RFC][PATCH 1/2] fs proc: make pagemap a privileged interface Kees Cook
     [not found] ` <20150309204322.50DA6B5D@viggo.jf.intel.com>
2015-03-09 21:32   ` [RFC][PATCH 2/2] proc: config options for making privileged /proc the default Kees Cook
2015-03-09 22:13 ` [RFC][PATCH 1/2] fs proc: make pagemap a privileged interface Eric W. Biederman
2015-03-09 22:22   ` Kees Cook
2015-03-09 23:08     ` Eric W. Biederman
2015-03-09 23:40       ` Kees Cook
2015-03-09 23:43       ` Eric W. Biederman
2015-03-10  0:03         ` Kees Cook
2015-03-10  2:51           ` Dave Hansen
2015-03-10  4:49             ` Eric W. Biederman
2015-03-10  2:28       ` Dave Hansen [this message]
2015-03-12 22:35 ` Andrew Morton
2015-03-13 15:56   ` Dave Hansen
2015-03-13 17:16     ` Eric W. Biederman

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