System And Method Of Dynamically Updating Stack Canaries

摘要

Various embodiments enhance protections against stack buffer overflow attacks in a computing device by dynamically updating stack canaries. Canary values on the stack of a child process may be replaced with new canary values in response to determining that a condition for generating new canary values is satisfied. Canary values on the stack of a child process may be replaced with new canary values when a child process is forked following a crash of a previous child process of the parent process. Canary values on the stack of a child process may be replaced with new canary values in response to expiration of a canary timeout time. The locations of the canaries to replace may be determined by walking the stack to locate entries in each stack frame that match a previous value of the canary or by walking the stack according to a predefined stack frame format.