How to Secure Linux by Patching in Real-Time

If anyone tells you that they know how to secure linux, but they fail to mention live patching – don’t listen to them. Keeping servers automatically up to date is key to keeping them safe. In the complex security question of how to secure Linux, patching live, in real-time, is the missing link.

Linux is a very stable OS, but it also has a very complicated kernel. The master branch of the Linux kernel git repository contains more than 20,000,000 lines of human-written code! With this much complexity comes vulnerabilities, some of them very threatening.

How to Secure Linux

To counter such vulnerabilities, Linux vendors are constantly providing partial patch updates for the kernel. It’s a constant whack-a-mole of Linux security. If you’re wondering how to secure Linux, this is a big part of the answer: always apply your patches, as quickly as possible!

However, right now, many organisations patch by rebooting their servers. Because rebooting is a major hassle, involving downtime and potential errors, people (understandably) delay for as long as they can, waiting until the patch releases have piled up to the point where they can’t be ignored anymore. But this is a bad, bad idea. Yes, most kernel vulnerabilities with the potential to trigger serious hacks are rare. You might have only a couple every year. But here’s the thing: when they come, they are ruinous. And every day that a vulnerability is discovered but not patched is another day when you are at risk.

So: how to secure Linux with smarter patching? Quit with the rebooting. Reboot-centred kernel Instead, you need live kernel patching.

Keep reading: A Need to Reboot is Delaying Kernel Patching & Making You Noncompliant

Live Kernel Patching

At KernelCare, our kernel team monitors security mailing lists. When a new patch is available for the active kernel, the agent downloads it and applies it to the running kernel, right away. With this system, kernel updates are applied as quickly as possible, protecting you from bad actors, and keeping you compliant. This happens without a moment of kernel downtime or any disruption of its operation. There is no need to reboot, no service interruptions or packet drops, and no need to kill any processes or user sessions.

There is a lot of discussion about how to secure Linux, but this one is a no-brainer. Rebootless kernel patching is like insurance: if you’re lucky, you’ll never find yourself in a bad situation. But if you do, you’ll be damn glad that you have it. And like insurance, rebootless kernel patching is not a nice-to-have; it is an absolute necessity for anyone who wants to stay safe.

To get the full lowdown on why rebooting your servers is making you insecure and noncompliant – and why it’s a matter of time until you discover this the hard way – read our full whitepaper here.

Keep reading: How to use a single key to register KernelCare on multiple servers