Kernel modules and security – an overview
An ironic reality is that enormous efforts spent on improving user-space security considerations have resulted in a large payoff over recent years. A malicious user performing a Buffer Overflow (BoF) attack was relatively straightforward a couple of decades back, but today it is really hard to pull off well. Why? Because there are many layers of beefed-up security mechanisms to prevent many of these attack classes.
To quickly name a few countermeasures: compiler protections (-fstack-protector[...], -Wformat-security, -D_FORTIFY_SOURCE=3), partial/full RELRO, better sanity and security checker tools (checksec.sh, address sanitizers, PaxTest, static analysis tools, and so on), secure libraries, hardware-level protection mechanisms (NX, SMEP, SMAP, and so on), [K]ASLR, better testing (fuzzing), and so on. Whew.
The irony is that kernel-space attacks have become increasingly common over the last several years! It has...
