Messages in this thread | | | From | Paul Moore <> | Date | Thu, 17 Feb 2022 17:32:39 -0500 | Subject | Re: [RFC PATCH] mm: create security context for memfd_secret inodes |
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On Thu, Feb 17, 2022 at 9:24 AM Christian Göttsche <cgzones@googlemail.com> wrote: > On Thu, 27 Jan 2022 at 00:01, Paul Moore <paul@paul-moore.com> wrote: > > On Tue, Jan 25, 2022 at 9:33 AM Christian Göttsche > > <cgzones@googlemail.com> wrote: > > > > > > Create a security context for the inodes created by memfd_secret(2) via > > > the LSM hook inode_init_security_anon to allow a fine grained control. > > > As secret memory areas can affect hibernation and have a global shared > > > limit access control might be desirable. > > > > > > Signed-off-by: Christian Göttsche <cgzones@googlemail.com> > > > --- > > > An alternative way of checking memfd_secret(2) is to create a new LSM > > > hook and e.g. for SELinux check via a new process class permission. > > > --- > > > mm/secretmem.c | 9 +++++++++ > > > 1 file changed, 9 insertions(+) > > > > This seems reasonable to me, and I like the idea of labeling the anon > > inode as opposed to creating a new set of LSM hooks. If we want to > > apply access control policy to the memfd_secret() fds we are going to > > need to attach some sort of LSM state to the inode, we might as well > > use the mechanism we already have instead of inventing another one. > > Any further comments (on design or implementation)? > > Should I resend a non-rfc?
I personally would really like to see a selinux-testsuite for this so that we can verify it works not just now but in the future too. I think having a test would also help demonstrate the usefulness of the additional LSM controls.
> One naming question: > Should the anonymous inode class be named "[secretmem]", like > "[userfaultfd]", or "[secret_mem]" similar to "[io_uring]"?
The pr_fmt() string in mm/secretmem.c uses "secretmem" so I would suggest sticking with "[secretmem]", although that is question best answered by the secretmem maintainer.
-- paul-moore.com
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