The mechanics behind the headlines
A logic bug buried in the Linux kernel's cryptographic subsystem since 2017 now lets any unprivileged user become root — reliably, silently, and in 732 bytes of Python. Here is exactly how it works, why containers make it worse, and what to do about it.
Before Linux can run, something else has to find it, load it into memory, and hand over control. That process starts with a CPU executing from a fixed address in firmware — with no kernel, no filesystem, and no concept of a process.
A program compiled for Linux won't run on Windows, and a macOS binary won't run on Linux. The reason isn't the code — it's what the binary expects the operating system to do for it.
Your machine is running hundreds of processes right now. Memory is being translated, interrupts are firing, the scheduler is switching contexts faster than you can blink. None of this appeared fully formed.
A program can't read a file, open a socket, or allocate memory without crossing into the kernel. Here's exactly how that crossing works — registers, privilege levels, and what strace shows you.