While static analysis is useful in detecting early-stage hardware security
bugs, its efficacy is limited because it requires information to form checks
and is often unable to explain the security impact of a detected vulnerability.
Large Language Models can be useful in filling these gaps by identifying
relevant assets, removing false violations flagged by static analysis tools,
and explaining the reported violations. LASHED combines the two approaches
(LLMs and Static Analysis) to overcome each other's limitations for hardware
security bug detection. We investigate our approach on four open-source SoCs
for five Common Weakness Enumerations (CWEs) and present strategies for
improvement with better prompt engineering. We find that 87.5% of instances
flagged by our recommended scheme are plausible CWEs. In-context learning and
asking the model to 'think again' improves LASHED's precision.