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
