3 ms·
From your link: > securelevel may no longer be lowered except by init > The list of securelevel's effects may not be comprehensive. So yes, it's a nice sandb
by shaded-enmity 4y ago
From your link:
> securelevel may no longer be lowered except by init
> The list of securelevel's effects may not be comprehensive.
So yes, it's a nice sandbox that can help prevent accidents, but doesn't sound like something you should rely on for actual defense.
- rollcat 4y agoYou sound like you're dismissing it, but even if it wasn't all that useful on its own, it's a part of defense in depth strategy - it's just one layer in a carefully thought out system. Pledge/unveil is another, so is privsep+imsg, W^X, (K)ASLR, syscall origin verification, boot-time libc/kernel relinking, and a couple dozen other features I can't even recall now. Most importantly, all of these features and mitigations are enabled by default, and are pretty much invisible to the end user or administrator; and actually easy to use for a developer. Contrast this with e.g. seccomp or SELinux. Google is even hinting "selinux permissive" and "selinux disable" in top 3 suggestions...