From: Eric Biggers <ebiggers@kernel.org>
To: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Theodore Ts'o <tytso@mit.edu>,
Amir Goldstein <amir73il@gmail.com>,
Richard Weinberger <richard@nod.at>,
Miklos Szeredi <miklos@szeredi.hu>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-fscrypt@vger.kernel.org,
overlayfs <linux-unionfs@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Paul Lawrence <paullawrence@google.com>
Subject: Re: overlayfs vs. fscrypt
Date: Wed, 13 Mar 2019 08:51:45 -0700 [thread overview]
Message-ID: <20190313155144.GC703@sol.localdomain> (raw)
In-Reply-To: <1552491394.3022.8.camel@HansenPartnership.com>
Hi James,
On Wed, Mar 13, 2019 at 08:36:34AM -0700, James Bottomley wrote:
> On Wed, 2019-03-13 at 11:16 -0400, Theodore Ts'o wrote:
> > So before we talk about how to make things work from a technical
> > perspective, we should consider what the use case happens to be, and
> > what are the security requirements. *Why* are we trying to use the
> > combination of overlayfs and fscrypt, and what are the security
> > properties we are trying to provide to someone who is relying on this
> > combination?
>
> I can give one: encrypted containers:
>
> https://github.com/opencontainers/image-spec/issues/747
>
> The current proposal imagines that the key would be delivered to the
> physical node and the physical node containerd would decrypt all the
> layers before handing them off to to the kubelet. However, one could
> imagine a slightly more secure use case where the layers were
> constructed as an encrypted filesystem tar and so the key would go into
> the kernel and the layers would be constructed with encryption in place
> using fscrypt.
>
> Most of the desired security properties are in image at rest but one
> can imagine that the running image wants some protection against
> containment breaches by other tenants and using fscrypt could provide
> that.
>
What do you mean by "containment breaches by other tenants"? Note that while
the key is added, fscrypt doesn't prevent access to the encrypted files.
fscrypt is orthogonal to OS-level access control (UNIX mode bits, ACLs, SELinux,
etc.), which can and should be used alongside fscrypt. fscrypt is a storage
encryption mechanism, not an OS-level access control mechanism.
- Eric
next prev parent reply other threads:[~2019-03-13 15:51 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-13 12:31 overlayfs vs. fscrypt Richard Weinberger
2019-03-13 12:36 ` Miklos Szeredi
2019-03-13 12:47 ` Richard Weinberger
2019-03-13 12:58 ` Miklos Szeredi
2019-03-13 13:00 ` Richard Weinberger
2019-03-13 13:24 ` Miklos Szeredi
2019-03-13 13:32 ` Richard Weinberger
2019-03-13 14:26 ` Amir Goldstein
2019-03-13 15:16 ` Theodore Ts'o
2019-03-13 15:30 ` Richard Weinberger
2019-03-13 15:36 ` James Bottomley
2019-03-13 15:51 ` Eric Biggers [this message]
2019-03-13 16:13 ` James Bottomley
2019-03-13 16:24 ` Richard Weinberger
2019-03-13 16:44 ` Theodore Ts'o
2019-03-13 17:45 ` James Bottomley
2019-03-13 18:58 ` Theodore Ts'o
2019-03-13 19:17 ` James Bottomley
2019-03-13 19:57 ` Eric Biggers
2019-03-13 20:06 ` James Bottomley
2019-03-13 20:25 ` Eric Biggers
2019-03-13 21:04 ` James Bottomley
2019-03-13 22:13 ` Eric Biggers
2019-03-13 22:29 ` James Bottomley
2019-03-13 22:58 ` Eric Biggers
2019-03-13 16:06 ` Al Viro
2019-03-13 16:44 ` Eric Biggers
2019-03-13 19:19 ` Al Viro
2019-03-13 19:43 ` Eric Biggers
2019-03-13 15:30 ` Eric Biggers
2019-03-13 20:33 ` Richard Weinberger
2019-03-13 22:26 ` Eric Biggers
2019-03-13 22:42 ` Richard Weinberger
2019-03-14 7:34 ` Miklos Szeredi
2019-03-14 17:15 ` [RFC] fscrypt_key_required mount option Richard Weinberger
2019-03-14 17:15 ` [PATCH 1/4] fscrypt: Implement FS_CFLG_OWN_D_OPS Richard Weinberger
2019-03-14 17:15 ` [PATCH 2/4] fscrypt: Export fscrypt_d_ops Richard Weinberger
2019-03-14 17:15 ` [PATCH 3/4] ubifs: Simplify fscrypt_get_encryption_info() error handling Richard Weinberger
2019-03-14 17:15 ` [PATCH 4/4] ubifs: Implement new mount option, fscrypt_key_required Richard Weinberger
2019-03-14 17:49 ` Eric Biggers
2019-03-14 20:54 ` Richard Weinberger
2019-03-14 23:07 ` Theodore Ts'o
2019-03-15 7:48 ` Richard Weinberger
2019-03-15 13:51 ` Theodore Ts'o
2019-03-15 13:59 ` Richard Weinberger
2019-03-14 23:15 ` James Bottomley
2019-03-14 23:42 ` Theodore Ts'o
2019-03-14 23:55 ` James Bottomley
2019-03-13 15:01 ` overlayfs vs. fscrypt Eric Biggers
2019-03-13 16:11 ` Al Viro
2019-03-13 16:33 ` Eric Biggers
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