Hacker News Reader

This goes both ways. Userland systems are susceptible to a myriad of attacks that a kernel, being privileged code, is not. We rely on the kernel (plus CPU rings) for most of the security enforcement in a machine, after all.

However, IF that code is compromised, the consequences are much more catastrophic.

View on HN

That sounds interesting.

Can you elaborate on which attacks userland system are susceptible to that a kernel is not?

A userland process can view/edit the memory of another userland process. Not so with kernel processes.

Viewing/editing of another userland process is usually done using ptrace(2). Yama Linux security module prevents that unless you are root to disable it. It is active by default on Ubuntu.

Also reading /proc/nnnn/mem does not work even for your own processes and even though file node protections seem to allow it, not sure where that security enhancement comes from.

Reply on news.ycombinator.com