Uploading selinuxnode test VM


Sven Vermeulen Mon 25 February 2013

At the time of writing (but I'll delay the publication of this post a few hours), I'm uploading a new SELinux-enabled KVM guest image. This is not an update on the previous image though (it's a reinstalled system - after all, I use VMs for testing, so it makes sense to reinstall from time to time to check if the installation instructions are still accurate). However, the focus remains the same:

  • A minimal Gentoo Linux installation for amd64 (x86_64) as guest within a KVM hypervisor. The image is about 190 Mb in size compressed, and 1.6 Gb in size uncompressed. The file format is Qemu's QCOW2 so expect the image to grow as you work with it. The file systems are, in total, sized to about 50 Gb.
  • The installation has SELinux enabled (strict policy, enforcing mode), various grSecurity settings enabled (including PaX and TPE), but now also includes IMA (Integrity Measurement Architecture) and EVM (Extended Verification Module) although EVM is by default started in fix mode.
  • The image will not start any network-facing daemons by default (unlike the previous image) for security reasons (if I let this image stay around this long as I did with the previous, it's prone to have some vulnerabilities in the future, although I'm hoping I can update the image more frequently). This includes SSH, so you'll need access to the image console first after which you can configure the network and start SSH (run_init rc-service sshd start does the trick).
  • A couple of default accounts are created, and the image will display those accounts and their passwords on the screen (it is a test/play VM, not a production VM).

There are still a few minor issues with it, that I hope to fix by the next upload:

  • Bug 457812 is still applicable to the image, so you'll notice lots of SELinux denials on the mknod capability. They seem to be cosmetic though.
  • At shutdown, udev somewhere fails with a SELinux initial context problem. I thought I had it covered, but I noticed after compressing the image that it is still there. I'll fix it - I promise ;)
  • EVM is enabled in fix mode, because otherwise EVM is prohibiting mode changes on files in /run. I still have to investigate this further though - I had to use the EVM=fix workaround due to time pressure.

When uploaded, I'll ask the Gentoo infrastructure team to synchronise the image with our mirrors so you can enjoy it. It'll be on the distfiles, under experimental/amd64/qemu-selinux (it has the 20130224 date in the name, so you can see for yourself if the sync has already occurred or not).