On Wed, Apr 21, 2021 at 10:38 PM Paul Moore <paul@xxxxxxxxxxxxxx> wrote: > On Wed, Apr 21, 2021 at 1:14 PM Ondrej Mosnacek <omosnace@xxxxxxxxxx> wrote: > > > > This series aims to correct a design flaw in the original anon_inode > > SELinux support that would make it hard to write policies for anonymous > > inodes once more types of them are supported (currently only userfaultfd > > inodes are). A more detailed rationale is provided in the second patch. > > > > The first patch extends the anon_inode_getfd_secure() function to accept > > an additional numeric identifier that represents the type of the > > anonymous inode being created, which is passed to the LSMs via > > security_inode_init_security_anon(). > > > > The second patch then introduces a new SELinux policy capability that > > allow policies to opt-in to have a separate class used for each type of > > anon inode. That means that the "old way" will still > > ... will what? :) Whoops, I thought I had gone over all the text enough times, but apparently not :) It should have said something along the lines of: ...will still work and will be used by default. > > I think it would be a very good idea if you could provide some > concrete examples of actual policy problems encountered using the > current approach. I haven't looked at these patches very seriously > yet, but my initial reaction is not "oh yes, we definitely need this". An example is provided in patch 2. It is a generalized problem that we would eventually run into in Fedora policy (at least) with the unconfined_domain_type attribute and so far only hypothetical future types of anon inodes. -- Ondrej Mosnacek Software Engineer, Linux Security - SELinux kernel Red Hat, Inc.
