Kernel live patching
Applying security fixes to a running Linux kernel without rebooting the server, useful when scheduled downtime is difficult to arrange.
Why this matters for uptime-sensitive servers
A kernel security fix traditionally requires a full reboot to take effect, which means a window of downtime, however brief, on every server that needs it. Live patching applies the fix to the running kernel in memory, avoiding that window entirely for supported updates.
Its limits
Not every kernel fix can be applied live; some structural changes still require a traditional reboot. Live patching is typically used to buy time until a scheduled maintenance window, rather than as a permanent substitute for eventually rebooting onto the fully updated kernel.
Frequently asked questions
Does live patching replace the need to ever reboot?
No. It defers the need for an immediate reboot for supported fixes, but a scheduled reboot is still generally recommended periodically to ensure the running kernel matches what is actually installed on disk.
Is kernel live patching available on every Linux distribution?
It depends on the distribution and often requires a specific subscription or package, such as Canonical Livepatch on Ubuntu or kpatch on RHEL-based systems.
Is live patching risky compared to a normal reboot?
It carries its own, generally small, risk profile, since it modifies a running kernel in memory, but for supported patches it is considered production-safe by the vendors who offer it.
Want to see where your own server stands?
Run the free, read-only server check, or open the Security Lab and watch the detect, contain, recover, verify loop in action.
Get your free server checkOpen the Security Lab