Understand Heap Exploitation Concepts

Implement a C program demonstrating heap exploitation concepts.

Requirements:

• Show heap chunk structure conceptually (size, fd, bk)
• Demonstrate use-after-free conceptually
• Demonstrate double-free conceptually
• Explain how heap metadata corruption leads to arbitrary writes
• Document modern allocator defenses (safe unlinking, tcache checks)
• Explain heap spraying concept

Success Criteria:

• Heap chunk structure is explained
• Use-after-free and double-free are documented
• Modern defenses are described