Class 07 · KP 06 / 18

What Is a Gadget?

A ROP chain: each 'ret' launches the next gadget already present in the code.

A gadget is a short sequence of instructions that ends in ret (0xc3).
Examples: pop rdi ; ret pop rsi ; pop r15 ; ret add rax, rbx ; ret
ret pops the next value off the stack into RIP.
So a stack full of {gadget addr, data, gadget addr, data, ...} becomes a program whose "instruction pointer" is the stack pointer.
Each ret advances us to the next gadget: the stack drives control flow.

Key Takeaway

The stack becomes the instruction stream; ret is the "fetch next gadget" engine.