# In OstiumLinkUpKeep, empty watchlist or keeperIds arguments are not handled Low/Info · Three Sigma · RWA perpetuals DEX · 19th February, 2024 Finding 3S-OS-L15 of the Ostium security review. - Protocol: https://www.ostium.com/ - Report: /reports/ostium - Source: https://cdn.sanity.io/files/qoqld077/production/a95b9c69e0f65d1d6b0e649f0d62a362358ca8ce.pdf --- ### Description In OstiumLinkUpKeep, functions [setWatchList()](https://github.com/0xOstium/smart-contracts-threeSigma/blob/dev/src/OstiumLinkUpKeep.sol#L131), [addToWatchList()](https://github.com/0xOstium/smart-contracts-threeSigma/blob/dev/src/OstiumLinkUpKeep.sol#L142) and [removeFromWatchList()](https://github.com/0xOstium/smart-contracts-threeSigma/blob/dev/src/OstiumLinkUpKeep.sol#L153) don't handle 0 length array inputs, which could lead to incorrect state. ### Recommendation Explicitly check for empty arrays. ### Status Addressed in [#c9ebe98](https://github.com/0xOstium/smart-contracts-threeSigma/pull/58/commits/c9ebe98d766cd8c8adf6477f59d6c745642cba72).