From: Florian Weimer <fweimer@redhat.com>
To: David Herrmann <dh.herrmann@gmail.com>, linux-kernel@vger.kernel.org
Cc: "Hugh Dickins" <hughd@google.com>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
"Matthew Wilcox" <matthew@wil.cx>,
"Karol Lewandowski" <k.lewandowsk@samsung.com>,
"Kay Sievers" <kay@vrfy.org>, "Daniel Mack" <zonque@gmail.com>,
"Lennart Poettering" <lennart@poettering.net>,
"Kristian Høgsberg" <krh@bitplanet.net>,
john.stultz@linaro.org, "Greg Kroah-Hartman" <greg@kroah.com>,
"Tejun Heo" <tj@kernel.org>,
"Johannes Weiner" <hannes@cmpxchg.org>,
dri-devel@lists.freedesktop.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, "Andrew Morton" <akpm@linux-foundation.org>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Ryan Lortie" <desrt@desrt.ca>,
"Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Subject: Re: [PATCH 0/6] File Sealing & memfd_create()
Date: Tue, 08 Apr 2014 15:00:28 +0200 [thread overview]
Message-ID: <5343F2EC.3050508@redhat.com> (raw)
In-Reply-To: <1395256011-2423-1-git-send-email-dh.herrmann@gmail.com>
On 03/19/2014 08:06 PM, David Herrmann wrote:
> Unlike existing techniques that provide similar protection, sealing allows
> file-sharing without any trust-relationship. This is enforced by rejecting seal
> modifications if you don't own an exclusive reference to the given file. So if
> you own a file-descriptor, you can be sure that no-one besides you can modify
> the seals on the given file. This allows mapping shared files from untrusted
> parties without the fear of the file getting truncated or modified by an
> attacker.
How do you keep these promises on network and FUSE file systems? Surely
there is still some trust involved for such descriptors?
What happens if you create a loop device on a sealed descriptor?
Why does memfd_create not create a file backed by a memory region in the
current process? Wouldn't this be a far more generic primitive?
Creating aliases of memory regions would be interesting for many things
(not just libffi bypassing SELinux-enforced NX restrictions :-).
--
Florian Weimer / Red Hat Product Security Team
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next prev parent reply other threads:[~2014-04-08 13:00 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-19 19:06 [PATCH 0/6] File Sealing & memfd_create() David Herrmann
2014-03-19 19:06 ` [PATCH 1/6] fs: fix i_writecount on shmem and friends David Herrmann
2014-03-19 19:06 ` [PATCH 2/6] shm: add sealing API David Herrmann
2014-03-19 19:06 ` [PATCH 3/6] shm: add memfd_create() syscall David Herrmann
2014-03-20 8:47 ` Cyrill Gorcunov
2014-03-20 9:01 ` Pavel Emelyanov
2014-03-20 11:29 ` David Herrmann
2014-03-20 11:50 ` Pavel Emelyanov
2014-03-20 19:22 ` John Stultz
2014-04-02 13:38 ` Konstantin Khlebnikov
2014-04-02 14:18 ` David Herrmann
2014-04-02 14:52 ` Konstantin Khlebnikov
2014-04-10 19:07 ` Andy Lutomirski
2014-03-19 19:06 ` [PATCH 4/6] selftests: add memfd_create() + sealing tests David Herrmann
2014-03-19 19:06 ` [PATCH man-pages 5/6] fcntl.2: document SHMEM_SET/GET_SEALS commands David Herrmann
2014-03-19 19:06 ` [PATCH man-pages 6/6] memfd_create.2: add memfd_create() man-page David Herrmann
2014-03-20 2:55 ` [PATCH 0/6] File Sealing & memfd_create() Greg Kroah-Hartman
2014-03-20 3:49 ` Linus Torvalds
2014-03-20 8:07 ` David Herrmann
2014-03-20 14:41 ` One Thousand Gnomes
2014-03-20 15:12 ` David Herrmann
2014-03-20 15:26 ` One Thousand Gnomes
2014-03-20 15:32 ` tytso
2014-03-20 15:39 ` One Thousand Gnomes
2014-03-20 15:48 ` David Herrmann
2014-03-20 16:38 ` tytso
2014-04-10 19:14 ` Andy Lutomirski
2014-04-10 20:32 ` Theodore Ts'o
2014-04-10 20:37 ` Andy Lutomirski
2014-04-10 20:49 ` David Herrmann
2014-04-10 21:16 ` Andy Lutomirski
2014-04-10 22:57 ` David Herrmann
2014-04-10 23:05 ` Andy Lutomirski
2014-04-10 23:16 ` David Herrmann
2014-04-10 23:32 ` Andy Lutomirski
2014-04-20 15:03 ` Pavel Machek
2014-06-17 9:48 ` Florian Weimer
2014-06-17 16:21 ` Andy Lutomirski
2014-04-10 14:45 ` Colin Walters
2014-04-10 19:15 ` Andy Lutomirski
2014-04-10 19:45 ` Colin Walters
2014-04-11 6:09 ` Alex Elsayed
2014-04-08 13:00 ` Florian Weimer [this message]
2014-04-09 21:31 ` David Herrmann
2014-04-22 9:10 ` Florian Weimer
2014-04-22 11:55 ` David Herrmann
2014-04-22 12:44 ` Florian Weimer
2014-04-22 12:55 ` David Herrmann
2014-04-10 19:17 ` Andy Lutomirski
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