Security and the Linux Kernel (LFD441)
Security expertise for Linux systems is in high demand and will remain so for the foreseeable future.
Description
Security expertise for Linux systems is in high demand and will remain so for the foreseeable future. Master Linux kernel security to protect critical infrastructure and open doors to high-impact roles in cybersecurity, staying ahead in the rapidly growing cybersecurity field.
Summary
Security expertise for Linux systems is in high demand and will remain so for the foreseeable future.
What You'll Learn
- The course covers the fundamentals of Linux kernel security, including memory protection, process management, system calls, and filesystem security.
- Students will learn about various security mechanisms in the Linux kernel, such as Mandatory Access Control (MAC), Linux Security Modules (LSM), and secureboot.
- Throughout the course, students will gain hands-on experience in securing both userspace and the Linux kernel through various security mechanisms.
Prerequisites
- Be proficient in the C programming language.
- Be familiar with basic Linux (UNIX) utilities such as ls, grep and tar.
- Be comfortable using any of the available text editors (e.g. emacs, vi, etc.).
- Experience with any major Linux distribution is helpful but not strictly required.
- Have experience equivalent to having taken LFD420: Linux Kernel Internals and Development.
- Pre-class preparation material will be provided before class.
Outline
37 modules
•
4 Days total
- Objectives
- Who You Are
- The Linux Foundation®
- Copyright and No Confidential Information
- The Linux Foundation® Training
- Certification Programs and Digital Badging
- Linux Distributions
- Platforms
- Things Change in Linux and Open Source Projects
- Kernel Versions
- Kernel Sources and Use of git
- Virtual Machine
- Why proxmox ®?
- Our Lab Environment
- Labs
- Overview on How to Contribute Properly
- Know Where the Code is Coming From: DCO and CLA
- Stay Close to Mainline for Security and Quality
- Study and Understand the Project DNA
- Figure Out What Itch You Want to Scratch
- Identify Maintainers and Their Work Flows and Methods
- Get Early Input and Work in the Open
- Contribute Incremental Bits, Not Large Code Dumps
- Leave Your Ego at the Door: Don't Be Thin-Skinned
- Be Patient, Develop Long Term Relationships, Be Helpful
- Why Security?
- Types of Security
- Vulnerabilities
- Layers of Protection
- Software Exploits
- Labs
- Components of the Kernel
- User-Space vs. Kernel-Space
- What are System Calls?
- Available System Calls
- Scheduling Algorithms and Task Structures
- Process Context
- Labs
- Why Deprecated
- __deprecated
- BUG() and BUG_ON()
- Computed Sizes for kmalloc()
- simple_strtol() Family of Routines
- strcpy(), strncpy(), strlcpy()
- printk() %p Format Specifier
- Variable Length Arrays
- Switch Case Fall-Through
- Zero-Length and One-Element Arrays in Structs
- Why ASLR?
- How to Use ASLR
- Disabling ASLR for Specific Programs
- Kernel Configuration
- Kernel Address Space Layout Randomization (KASLR)
- How KASLR Works
- Enabling KASLR
- Labs
- Benefits
- How Structure Randomization Works
- Structure Initialization
- Opt-in vs Opt-out
- Partial Randomization
- Enabling Structure Randomization
- Building Out-of-tree Modules with Structure Randomization
- Linux Kernel Security Basics
- Discretionary Access Control (DAC)
- POSIX ACLs
- POSIX Capabilities
- Namespaces
- Linux Security Modules (LSM)
- Netfilter
- Cryptographic Methods
- The Kernel Self Protection Project
- Introduction to CGroups
- Overview
- Components of CGroup
- cgroup initialization
- cgroup Activation
- cgroups Parameters
- Testing cgroups
- systemd and cgroups
- Labs
- BPF
- eBPF
- Installation
- bcc Tools
- bpftrace
- Labs
- What is seccomp
- The seccomp Interface
- seccomp Strict Mode
- seccomp Filter Mode
- Labs
- Why Secure Boot?
- Secure Boot x86
- Embedded Systems Secure Boot
- Labs
- What is Module Signing?
- Basics of Signatures
- Module Signing Keys
- Enabling Module Signature Verification
- How It Works
- Signing Modules
- Labs
- Why IMA?
- Conceptual Operations
- Modes of Operation
- Collect Mode (Collect and Store)
- Logging Mode (Appraise and Audit)
- Enforcing Mode (Appraise and Protect)
- Extended Verification Module (EVM)
- Labs
- What is dm-verity?
- How dm-verity Works
- Enabling dm-verity
- Setting up dm-verity
- Using dm-verity
- Signing with dm-verity
- Booting with dm-verity
- Labs
- Why Encrypted Storage?
- Data Encryption Solutions
- Survey of Storage Encryption Options
- Block Encryption
- Block Encryption Use
- Filesystem Encryption
- Filesystem Encryption Use
- Layered Filesystem Encryption
- Layered Filesystem Encryption Use
- Labs
- What are Linux Security Modules?
- LSM Basics
- LSM Choices
- How LSM Works
- An LSM Example: Yama
- Labs
- SELinux
- SELinux Overview
- SELinux Modes
- SELinux Policies
- Context Utilities
- SELinux and Standard Command Line Tools
- SELinux Context Inheritance and Preservation
- restorecon
- semanage fcontext
- Using SELinux Booleans
- getsebool and setsebool
- Troubleshooting Tools
- Labs
- What is AppArmor?
- Checking Status
- Modes and Profiles
- Profiles
- Utilities
- Why Yama?
- Configuring Yama
- How Yama Works
- Labs
- Why LoadPin?
- Enabling LoadPin
- Using LoadPin
- How LoadPin Works
- Why Lockdown?
- Lockdown Modes
- What Things are Locked Down?
- How It Works
- A Few Notes
- Labs
- Why Safesetid?
- Configuring Safesetid
- How Safesetid Works
- Labs
- What is netfilter?
- Netfilter Hooks
- Netfilter Implementation
- Hooking into Netfilter
- Iptables
- nftables
- Labs
- What are netlink Sockets?
- Opening a netlink Socket
- netlink Messages
- Labs
- Evaluation Survey
- UNIX and Linux
- Monolithic and Micro Kernels
- Object-Oriented Methods
- Main Kernel Components
- User-Space and Kernel-Space
- Task Structure
- Memory Allocation
- Transferring Data between User and Kernel Spaces
- Object-Oriented Inheritance - Sort Of
- Linked Lists
- Jiffies
- Labs
- What are Modules?
- A Trivial Example
- Compiling Modules
- Modules vs Built-in
- Module Utilities
- Automatic Module Loading
- Module Usage Count
- Module Licensing
- Exporting Symbols
- Resolving Symbols
- Labs
- Processes, Threads, and Tasks
- Kernel Preemption
- Real Time Preemption Patch
- Labs
- Installation and Layout of the Kernel Source
- Kernel Browsers
- Kernel Configuration Files
- Kernel Building and Makefiles
- initrd and initramfs
- Labs
- Coding Style
- Using Generic Kernel Routines and Methods
- Making a Kernel Patch
- sparse
- Using likely() and unlikely()
- Writing Portable Code, CPU, 32/64-bit, Endianness
- Writing for SMP
- Writing for High Memory Systems
- Power Management
- Keeping Security in Mind
- Labs
- Concurrency and Synchronization Methods
- Atomic Operations
- Bit Operations
- Spinlocks
- Seqlocks
- Disabling Preemption
- Mutexes
- Semaphores
- Completion Functions
- Read-Copy-Update (RCU)
- Reference Counts
- Labs
- Virtual Memory Management
- Systems With and Without MMU and the TLB
- Memory Addresses
- High and Low Memory
- Memory Zones
- Special Device Nodes
- NUMA
- Paging
- Page Tables
- page structure
- Labs
- Requesting and Releasing Pages
- Buddy System
- Slabs and Cache Allocations
- Memory Pools
- kmalloc()
- vmalloc()
- Early Allocations and bootmem()
- Memory Defragmentation
- Labs
