Unidentified Causes of MultiFuzz Runtime Errors

Identify the causes of the `InternalError` and `UnknownError` failures reported by MultiFuzz during ARM Cortex-M firmware emulation and fuzzing initialization.

Background

The large-scale evaluation categorizes failures produced by MultiFuzz during emulation-based fuzzing of ARM Cortex-M firmware. Among the minor “Other” failure categories, the study records InternalError and UnknownError cases but does not determine what causes them. Resolving these causes is necessary for distinguishing implementation defects from failures caused by firmware behavior, inaccurate emulation, or other pipeline limitations.

References

The causes of InternalError and UnknownError remain unidentified.

— SoK: A Large-Scale Empirical Study of Emulation-Based Dynamic Analysis Research for ARM Cortex-M Firmware (Extended Version)  (2609.38872 - Li et al., 30 Sep 2026) in Appendix, subsection “Crash Counts in Minor ‘Other’ Categories,” paragraph following Table `multifuzz_minor`