ShadowStack: A new approach for secure program execution

In recent years, computer systems belonging to large companies, governments as well as personal computers have been experiencing an increasing wave of attacks that disrupt their normal operation or leak sensitive data. This implies in loss of privacy, financial and national security damages. In this context, “computer security” is no longer an afterthought. Dynamic integrity checking has emerged as a possible solution to protect computer systems by thwarting various attacks. In this context, this paper presents ShadowStack, a new dynamic integrity checking technique based on a watchdog implemented in hardware. The watchdog observes specific instructions in the code being executed through the processor pipeline, compares them against reference values generated at runtime and in the event of detecting a tentative of intrusion, the pipeline is stalled and the instructions are not allowed to commit by flushing them from the pipe. The attack type is stack smashing buffer overflow. This threatening type is by far the most common found in the literature. Experimental results obtained throughout simulations demonstrate the technique's efficiency and the corresponding overheads incurred by the use of the proposed approach.