Following the Pebble Trail
Bogdan Pavel Deac, Adrian Coleşa · 2020
It is widely known that return-oriented programming (ROP) attack can be mounted on x86, ARM and SPARC architectures. However, it remained an open question if ROP was possible on RISC-V, a new and promising free and open instruction set architecture (ISA). In this paper we present a novel ROP technique specific to RISC-V architecture. Our method relies on the processor's saved registers and its function calling convention. We use functional gadgets (that perform primitive operations) ended in a jump instruction to an address held in a saved register. The order of gadgets chaining is given by a novel gadget, which we call the charger gadget, which loads the saved registers with the gadgets? addresses from the stack. We constructed a library of gadgets extracted from the standard Linux libraries. Finally, we evaluated our method by exploiting a buffer-overflow vulnerable application.