I am not satisfied with Linux’s security and have been researching alternative open source OS for privacy and security So far only thing that’s ready to use is GrapheneOS (Based on Android) but that’s not available on desktop (Though when Android release Desktop mode it may become viable)
Qubes OS is wrapper around underlying operating systems, so it doesn’t really fix for example Linux’s security holes it just kinda sandbox/virtualize them
OpenBSD is more secure than Linux on a base level but lack mitigations and patches that are added to linux overtime and it’s security practices while good for it’s time is outdated now
RedoxOS (Written in Rust) got some nice ideas but sticks to same outdated practices and doesn’t break the wheel too much, and security doesn’t seems to be main focus of OS
Haiku and Serenity are outright worse than Linux, especially Haiku as it’s single user only
Serenity adopted Pledge and Unveil from OpenBSD but otherwise lacks basic security features
All new security paradigms seems to be happening in microkernels and these are the ones that caught my eyes
None of these are ready to be used as daily driver OS but in future (hopefully) it may change
Genode seems to be far ahead of game than everything else
Ironclad Written in ADA
Atmosphere And Mesosphere Open Source Re-implementation of Nintendo Switch’s Horizon OS, I didn’t expected this to be security-oriented but seems like Nintendo has done a very solid job
Then there are Managarm, HelenOS, Theseus but I couldn’t figure out how secure they are
Finally there is Kicksecure from creators of Whonix, Kicksecure is a linux distro that plans to fix Linux’s security problems
if you know of any other OS please share it here
I’ve not come across such a topic in a while; what security issues do you see with monolithic kernels that are not present in Microkernels? Other than the “more code so more bugs” part
Worse performance and increased attack surface due to substantial increase in number of system calls required for any given task?
Oh. You were asking how microkernels are better… They’re smaller. I think that’s about it. Great for things like RTOS where the scope of the kernel is much more limited, specialized, and likely needs to live in an MCU’s tiny ROM.
As I understand it, a crude way to specify a micro kernel might be to call it a specialised slice of a monolithic kernel. It’s still a kernel, and it being more/less efficient, have better security etc depends on the code itself rather than something external.
Understandably, I understand that the motivation comes from a combination of embedded projects: I remember that Minix is still a good example of a micro-kernel albeit being extremely vulnerable and buggy. Microkernels are nice, but I suppose one should look for a compromise when thinking of an OS based on Linux which runs around the world, and having a specialised kernel might not be the best idea.
You’ve got a lot of it, yeah. A microkernel tends to try to implement the smallest amount of essential functionality needed. When used in a specialized environment, like embedded controllers (ex. ZMK firmware, which is built on the Zephyr Kernel), microkernels are great and can exhibit great performance and efficiency.
Once one starts trying to build a general-purpose OS with a microkernel, however, things deteriorate very quickly. Things that are essential for general-purpose computing usually do not make it into the scope of the microkernel’s functionality. This means that anytime something as simple as opening a file is required, a lot more communication is needed between processes, increasing the number of times that calls need to cross between the kernel and user context boundary.
Every context change requires one or more operations and the isolation necessary to be secure, means that they microkernel has to act as a messenger any time that a subsystem needs to communicate with another. The total number of system calls grows at an exponential rate, killing performance and increasing the threat surface that an adversary can target (individual components even end up needing greater awareness of security because there are now a lot more potential “weak links” in the data transmission chain).
That’s why a suitable middle-of-the-road approach seems to be statically compiling one’s kernel with the least amount of add-ons (drivers - that’s what most of the kernel is anyway) possible. I see it as a decent idea but annoying in practice since bigger updates mean either a script/manual intervention every time, and I like Debian so you can see how I perceive that.
Exactly. And it also introduces limitations, should your system usage exceed the bounds expected and established when compiling. Like so many other things, context matters.
And now we’ve come a full circle. Microkernels are better because they have less code, but to make them usable across various systems you’d need to add more code. And after a point it’ll stop being a micro kernel.