Laoise Nic Giolla Uidhir on Nostr: "With securelevel, they are locked out of the kernel.” except that ...

"With securelevel, they are locked out of the kernel.”

except that /boot/kernel/kernel isn't schg, so they can just replace the kernel itself and wait for you to reboot. but then, if they can replace /boot/kernel/kernel, they already have root... so what is securelevel protecting against?

if the answer is persistence - did you modify *every* executable that root can run (including everything installed from ports/packages) to ensure it can't be replaced? did you make atrun and crontab read-only (thus breaking at(1) for everyone on the system)?

if you're put the required effort into building a system which is actually secure enough for schg/securelevel to make a difference, perhaps it can marginally increases security, but your original toot makes it sound like simply setting securelevel increases security, which it doesn’t. and i think it's a shame we trick users into thinking it does by calling it 'securelevel'. (it should be called immutable_level, or something, or more usefully, split into multiple sysctls.)