A KAIST research team has developed a groundbreaking system to detect concurrency bugs in CPUs based on out-of-order execution such as Apple M3 processor. Using this newly developed automated technology, the research team identified a total of 11 new bugs in Linux, including several critical ones that could cause severe damage to systems in the Linux kernel, an operating system used for servers

The research team led by Professors Youngjin Kwon and Inshik Shin has developed an operating system bug detection system capable of identifying and diagnosing concurrency bugs caused by out-of-order execution on ARM servers and devices equipped with Apple processors—all without requiring physical CPU hardware.

A notable feature of the developed bug detection technology is its ability to accurately and efficiently emulate such Apple processors called OEMU (Out-of-order EMUlator) as shown in the above figure. This means that even without access to Apple processors or ARM servers, a commonly used Intel CPU-based server can run the operating system in an emulated environment to detect these bugs.

Using this newly developed technology, the research team identified and reported 11 new concurrency bugs in the latest Linux operating system, providing patches to Linux developers. These bugs were found across critical kernel components, including TLS code used for encrypted networks, posing significant security risks.

The team’s technology is not limited to Linux; it is also applicable to other operating systems, such as Android, commonly used on mobile devices, and Windows. Its potential applications are expected to expand significantly in the future. This research was recognized as a Best Paper at the 2024 Symposium on Operating Systems Principles (SOSP), the most prestigious conference in the field of systems research. The research outcomes are publicly available as open source: