ASFuzz: Detecting Linux Kernel Asynchronous Concurrency Bugs via Asynchronous Shadow Fuzzing

ASFuzz is a testing tool that finds concurrency bugs (problems caused by multiple tasks running at the same time) in the Linux kernel, specifically bugs involving asynchronous tasks (operations that happen in the background without waiting for a response). The tool uses a Shadow Dependency Graph (a map of how different tasks relate to and trigger each other) and a dual-mode approach to explore both normal execution paths and stress-test specific interactions between synchronous (waiting) and asynchronous operations. ASFuzz discovered 14 previously unknown bugs in Linux kernel versions 6.6 to 6.15, including 10 asynchronous concurrency bugs, with 5 assigned CVE identifiers (official security vulnerability numbers).