Fuzzing Zephyr Apps - Struggles of Dynamic Analysis on Embedded Applications - Jayashree Srinivasan

Join us at the premier vendor-neutral open source conference, where developers and technologists come together to collaborate, share knowledge, and explore the latest innovations and advancements in open source technology. Learn more at https://events.linuxfoundation.org/ Fuzzing Zephyr Apps - Struggles of Dynamic Analysis on Embedded Applications - Jayashree Srinivasan, Analog Devices Fuzzing, a type of dynamic analysis, is a testing method to find security flaws in software during execution. It involves providing randomized inputs to the application and observing for crashes. Embedded applications present unique fuzzing challenges. Unlike general-purpose software, they run continuously in real-time without terminating, making it hard to use traditional fuzzing approaches. They receive inputs through specialized peripherals or direct memory/register accesses that require accurate modeling. Fuzzers must generate inputs satisfying highly constrained validation checks while maintaining application state, and crash detection is complicated by the lack of clear program termination. Existing solutions use hardware, emulation, or rehosted systems with modeled peripherals, employing full source code level, binary-only or API-level fuzzing. Zephyr's current libFuzzer integration targets unit-level API fuzzing but misses system-wide bugs. We aim to integrate AFL++, a popular fuzzing engine, to create a generalized fuzzing strategy across Zephyr's supported platforms. Though still in development, we're exploring the optimal approach to achieve this integration.