From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Biggers Subject: Re: [RFC PATCH v3 00/18] fscrypt: key management improvements Date: Wed, 20 Feb 2019 10:36:20 -0800 Message-ID: <20190220183619.GA177939@gmail.com> References: <20190220065249.32099-1-ebiggers@kernel.org> <14023.1550686042@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <14023.1550686042@warthog.procyon.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+gldm-linux-mtd-36=gmane.org@lists.infradead.org To: David Howells Cc: linux-ext4@vger.kernel.org, linux-api@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-crypto@vger.kernel.org, linux-fsdevel@vger.kernel.org, Satya Tangirala , Paul Crowley List-Id: linux-f2fs-devel.lists.sourceforge.net Hi David, On Wed, Feb 20, 2019 at 06:07:22PM +0000, David Howells wrote: > I have a couple of patches that add ACLs to keyrings, that you can find at the > top of the branch here: > > https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=keys-acl > > I have other patches that allow tags to be used as subjects in the ACL, with a > container supplying a tag, e.g.: > > https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/commit/?h=container&id=e0fdc5613a32b9475b025f58e7a2267329b3f3a4 > > Might something similar be of use to you here, perhaps specifying a tag > referring to the blockdev of interest rather than the container? > > David I don't think so. The main point of adding keys directly to the filesystem is that it's generally inappropriate to apply OS-level access control or process-based visibility restrictions to fscrypt keys given that: - The unlocked/locked status of files is already filesystem-level. - The purpose of encryption is orthogonal to OS-level access control. The ioctl based interface also makes it *much* easier to implement all the semantics needed for removing fscrypt keys. I don't see how key ACLs would be appropriate here, except that key ACLs would allow userspace to opt-in to fixing the denial of service vulnerability where keyctl_invalidate() only requires Search permission. But for fscrypt that's addressed by my proposal too, and is just one of many problems it addresses. - Eric ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/