MultiWithDefaultProviderSelector Manual Review Findings

MWD-01M: Incorrect Assignment

Type	Severity	Location
Language Specific		MultiWithDefaultProviderSelector.sol:L121

Description:

The referenced statement is meant to assign the zero-address to the _currentProvider, however, it instead performs an equality check causing the system to enter a corrupt state when the default provider is removed.

Impact:

Presently, a removal of the default provider will cause them to not be in the validProviders entry but still be yielded by the MultiWithDefaultProviderSelector::getProvider function which we consider invalid behaviour.

Example:

Copy
114function _removeProvider(address provider) internal {
115    if (provider == address(0)) revert ZeroAddressProvider();
116    if (!this.isValidProvider(provider)) revert ProviderNotFound();
117
118    validProviders[provider] = false;
119
120    if (provider == _currentProvider) {
121        _currentProvider == address(0);
122    }
123}

Recommendation:

We advise the referenced line to have one = character omitted, ensuring it is properly performed as an assignment.

Alleviation (e6f704512a03e960f6cd0802fb70aa284591fe37):

The assignment has been corrected, ensuring that the default provider is correctly cleared when it has been removed.