The Governance.sol contract, which plays a pivotal role in managing governance operations within the zkSync protocol, is designed to inherit both the IGovernance interface and the Ownable2Step contract. During the contracts deployment, the initial ownership is assigned to the _admin address through the Governance.constructor:
Take a look at https://github.com/code-423n4/2024-03-zksync/blob/4f0ba34f34a864c354c7e8c47643ed8f4a250e13/code/contracts/ethereum/contracts/governance/Governance.sol#L43-L45
This design ensures that critical functions, such as scheduleTransparent and scheduleShadow, are exclusively accessible by the _admin (owner) of the contract. However, the incorporation of the Ownable2Step contract, which extends the Ownable abstract contract, introduces a significant risk. The Ownable contract includes a renounceOwnership function allowing the current owner to relinquish ownership rights, effectively setting the owner to the zero address:
If the _admin executes the renounceOwnership function, it would render all owner-exclusive functionalities, including upgrade scheduling, inoperative, thereby crippling the entire zkSync protocol.
By renouncing ownership, the _admin could unilaterally disable key governance functionalities. Such an action would not only undermine the protocols integrity but also eliminate any possibility of future upgrades, posing a severe threat to the systems sustainability and security.
To safeguard the protocol against potential sabotage through ownership renunciation, it is advisable to override the renounceOwnership function within the Governance.sol contract. By explicitly reverting any attempts to renounce ownership, this modification ensures the continuity and inviolability of governance operations:
