Simplicity is a form of art...

Audit buffering and rate limiting

Be it because of SELinux experiments, or through general audit experiments, sometimes you'll get in touch with a message similar to the following:

audit: audit_backlog=321 > audit_backlog_limit=320
audit: audit_lost=44395 audit_rate_limit=0 audit_backlog_limit=320
audit: backlog limit exceeded

The message shows up when certain audit events could not be …

Use change management when you are using SELinux to its fullest

If you are using SELinux on production systems (with which I mean systems that you offer services with towards customers or other parties beyond you, yourself and your ego), please consider proper change management if you don't do already. SELinux is a very sensitive security subsystem - not in the sense …

Moving closer to 2.4 stabilization

The SELinux userspace project has released version 2.4 in february this year, after release candidates have been tested for half a year. After its release, we at the Gentoo Hardened project have been working hard to integrate it within Gentoo. This effort has been made a bit more difficult …

CIL and attributes

I keep on struggling to remember this, so let's make a blog post out of it ;-)

When the SELinux policy is being built, recent userspace (2.4 and higher) will convert the policy into CIL language, and then build the binary policy. When the policy supports type attributes, these are …

SELinux is great for enterprises (but many don't know it yet)

Large companies that handle their own IT often have internal support teams for many of the technologies that they use. Most of the time, this is for reusable components like database technologies, web application servers, operating systems, middleware components (like file transfers, messaging infrastructure, ...) and more. All components that are …

Why does it access /etc/shadow?

While updating the SELinux policy for the Courier IMAP daemon, I noticed that it (well, the authdaemon that is part of Courier) wanted to access /etc/shadow, which is of course a big no-no. It doesn't take long to know that this is through the PAM support (more specifically, pam_unix …

Sometimes I forget how important communication is

Free software (and documentation) developers don't always have all the time they want. Instead, they grab whatever time they have to do what they believe is the most productive - be it documentation editing, programming, updating ebuilds, SELinux policy improvements and what not. But they often don't take the time to …

No more DEPENDs for SELinux policy package dependencies

I just finished updating 102 packages. The change? Removing the following from the ebuilds:

DEPEND="selinux? ( sec-policy/selinux-${packagename} )"

In the past, we needed this construction in both DEPEND and RDEPEND. Recently however, the SELinux eclass got updated with some logic to relabel files after the policy package is deployed …

Using multiple priorities with modules

One of the new features of the 2.4 SELinux userspace is support for module priorities. The idea is that distributions and administrators can override a (pre)loaded SELinux policy module with another module without removing the previous module. This lower-version module will remain in the store, but will not …

Migrating to SELinux userspace 2.4 (small warning for users)

In a few moments, SELinux users which have the \~arch KEYWORDS set (either globally or for the SELinux utilities in particular) will notice that the SELinux userspace will upgrade to version 2.4 (release candidate 5 for now). This upgrade comes with a manual step that needs to be performed …