Runtime Recovery for Integer Overflows

Despite decades of effort in research and engineering, integer overflows remain a severe threat to software security. Many tools are developed to detect integer overflows at runtime. However, the vast majority of them terminates program execution when an integer overflow is detected. This essentially causes denial-of-service, which is undesirable in many scenarios in practice. We propose a recovery mechanism designed for safe recovery from integer overflows. The recovery mechanism detects integer overflows and rectifies the values involved in arithmetic operations causing integer overflows so that it prevents the occurrence of the integer overflows and enables the program to continue execute safely. We have designed and developed a tool called RIO that can automatically synthesize and instrument our recovery mechanism into target programs. Our evaluation shows that RIO can successfully synthesize and instrument the recovery mechanism into programs containing real world vulnerabilities and the instrumented recovery mechanism allows the programs to recover safely in the face of exploits intending to trigger the vulnerabilities.