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The idea that root has absolute privileges, or even that it is, like in the olden Linux days, kernel-equivalent (through /dev/kmem, ioperm etc.), is outdated.
by anyfoo 6y ago
The idea that root has absolute privileges, or even that it is, like in the olden Linux days, kernel-equivalent (through /dev/kmem, ioperm etc.), is outdated.
Nowadays, the focus going forward is much more on giving every piece the privileges it needs, and not have an "absolute privilege" entity. (Outside of the kernel, although even for that it's less and less true anymore.)
- anyfoo 6y agoAs for not planning to run untrusted code in any of those pieces: It's bad if compromise through bugs of any component, however tiny, potentially leads to the ability to siphon off secrets from your server globally.
- inetknght 6y ago> The idea that root has absolute privileges, or even that it is, like in the olden Linux days, kernel-equivalent (through /dev/kmem, ioperm etc.), is outdated. No. A million times no. Absolutely no. It is not. You are doing a disservice to actual real people when you take away what they own. I own my hardware. I am root. I have absolute privileges. The idea that root has absolute privileges is the core if why I use Linux.
- megous 6y agoDon't panic, just read man capabilities and breath deeply.
- inetknght 6y agoNo. `root` should always have _full_ capabilities. Capabilities are there to allow non-root users access to some root systems
- great22221 6y agoYou are right I think. No idea why you're getting downvoted.
- spijdar 6y agoYou own the hardware, which means you have the ability to boot the system into diagnostic or repair modes for extended privileges. This doesn't mean that during normal operation there should be a superuser account with 100% access. Plan9 from Bell Labs pioneered (edit: they probably weren't the first, but it's the first OS I can think of that does this pervasively -- I bet mainframe systems are similar but that ain't my cup of tea) the idea back in the 90s, where certain processes (like the credential store factotum) were sealed off even from the root equivalent. If you had physical access, you could add a flag at boot to enable access to these services, but this was not enabled by default, which is good.
- pjmlp 6y agoVMS is one example, not only mainframes. Which is why NT was designed from the ground up with capabilities.
- megous 6y agoHad you actually read the manpage you'd realize that "root" has full capabilities, except where you configure it not to for specific processes or under specific conditions that are under your control, which is mostly for situations around setuid-0 marked binaries.