100 Linux think you need to know

#kernel #linux

x86 Protection Rings Model

CPU Security Layers for Privilege Separation
In x86 architecture, Protection Rings divide code execution into 4 levels (from Ring 0 with highest CPL to Ring 3 with lowest) to prevent unauthorized access to sensitive resources. This model operates via segment denoscriptors in the GDT and privilege checks (e.g., DPL).

Ring 0 (Kernel Mode):
Full access to CPU and memory; manages scheduler, paging, and interrupts. Only trusted code executes here.

Ring 1 (Driver Mode):
Medium privilege for device drivers; access to I/O ports and DMA, but limited to secure transitions.

Ring 2:
Legacy and rare; for specific execution domains.

Ring 3 (User Mode):
User applications; restricted to non-privileged instructions and system calls (via SYSCALL/INT).


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#os #linux #cpu #ring_model #privilege

learning golang for free
https://github.com/dariubs/GoBooks

Linux Tutorial

This research used the ALICE High Performance Computing Facility at the University of Leicester

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#linux #lpic

how to use the Havoc framework and develop Beacon Object Files

https://lorenzomeacci.com/the-havoc-framework


#c2 #BOF

Portable Executable "PE" anatomy

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#PE #windows

The art of data exfiltration

#Exfiltration