Sky L2MulticallSpell

About Sky L2MulticallSpell

L2MulticallSpell is a generic L2 spell for Sky governance. Deployed once per L2 and delegatecalled by the L2 governance relay, it executes a batch of calls encoded in the L1 spell, so that no dedicated L2 spell has to be deployed for simple actions.

Audit Summary

We have conducted a thorough review of the scope. The most important areas covered in our review are:

• Functional correctness of execute, since it runs with the full privileges of the L2 governance relay: the calls are executed atomically and in order, revert data is bubbled correctly, and the deadline is enforced.
• The integration with every L2 governance relay the spell is intended for (OP Stack, Arbitrum, and LayerZero with and without timelock), since the spell’s guarantees depend on how messages are delivered and retried. We highlight that anyone can retry a failed message until its deadline, see Choosing the Deadline.
• Access control, since execute is permissionless: the spell has no power of its own, as long as it is never granted any permission.

The report contains two system considerations and no issues.

In summary, we find that the codebase provides a high level of security, if operated under the assumptions documented in System Overview, Trust Model and System Considerations.

It is important to note that security audits are time-boxed and cannot uncover all vulnerabilities. They complement but don’t replace other vital measures to secure a project.