sayan_ - gas limit DoS via unbounded loop

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sayan_

medium

gas limit DoS via unbounded loop

Summary

Unbounded loop in accrueAll(),whitelistTokens(),whitelistSpells(),whitelistContracts() can lead to DoS

Vulnerability Detail

If a very large array of token/spell/contract addresses is passed in the mentioned functions then the the loop inside has to iterate through all of that & perform all the instructions.With all of this happening in the loop and costing gas it may revert due to exceeding the block size gas limit.

Impact

Execution fails due to exceeding the block size gas limit

Code Snippet

BlueBerryBank.sol#L261-#L265

File: contracts/BlueBerryBank.sol
261:     function accrueAll(address[] memory tokens) external {
262:         for (uint256 idx = 0; idx < tokens.length; idx++) {
263:             accrue(tokens[idx]);
264:         }
265:     }

BlueBerryBank.sol#L140-#L146

File: contracts/BlueBerryBank.sol
140:         for (uint256 idx = 0; idx < contracts.length; idx++) { 
141:             if (contracts[idx] == address(0)) {
142:                 revert ZERO_ADDRESS();
143:             }
144:             whitelistedContracts[contracts[idx]] = statuses[idx];
145:         }

BlueBerryBank.sol#L158-#L164

File: contracts/BlueBerryBank.sol
158:         for (uint256 idx = 0; idx < spells.length; idx++) { 
159:             if (spells[idx] == address(0)) {
160:                 revert ZERO_ADDRESS();
161:             }
162:             whitelistedSpells[spells[idx]] = statuses[idx];
163:         }

BlueBerryBank.sol#L176-#L181

File: contracts/BlueBerryBank.sol
176:         for (uint256 idx = 0; idx < tokens.length; idx++) {//@audit unbounded loop DoS
177:             if (statuses[idx] && !oracle.support(tokens[idx]))
178:                 revert ORACLE_NOT_SUPPORT(tokens[idx]);
179:             whitelistedTokens[tokens[idx]] = statuses[idx];
180:         }

Tool used

Manual Review

Recommendation

Consider avoiding all the actions executed in a single transaction, especially when calls are executed as part of a loop.