[PATCH v2 0/6] Harden userfaultfd

[Daniel Colascione]

On Tue, Feb 11, 2020 at 3:13 PM Casey Schaufler <casey at schaufler-ca.com> wrote:
>
> On 2/11/2020 2:55 PM, Daniel Colascione wrote:
> > Userfaultfd in unprivileged contexts could be potentially very
> > useful. We'd like to harden userfaultfd to make such unprivileged use
> > less risky. This patch series allows SELinux to manage userfaultfd
> > file descriptors and allows administrators to limit userfaultfd to
> > servicing user-mode faults, increasing the difficulty of using
> > userfaultfd in exploit chains invoking delaying kernel faults.
> >
> > A new anon_inodes interface allows callers to opt into SELinux
> > management of anonymous file objects. In this mode, anon_inodes
> > creates new ephemeral inodes for anonymous file objects instead of
> > reusing a singleton dummy inode. A new LSM hook gives security modules
> > an opportunity to configure and veto these ephemeral inodes.
> >
> > Existing anon_inodes users must opt into the new functionality.
> >
> > Daniel Colascione (6):
> >   Add a new flags-accepting interface for anonymous inodes
> >   Add a concept of a "secure" anonymous file
> >   Teach SELinux about a new userfaultfd class
> >   Wire UFFD up to SELinux
> >   Let userfaultfd opt out of handling kernel-mode faults
> >   Add a new sysctl for limiting userfaultfd to user mode faults
>
> This must be posted to the linux Security Module list
> <linux-security-module at vger.kernel.org>

Added. I thought selinux@ was sufficient.