Tadle
Tadle
DeFiFoundry
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Submission Details
Severity: low
Invalid

CapitalPool will not work for some tokens that don't support approve type(uint256).max amount

vladzaev

Summary

CapitalPool will not work for some tokens that don't support approve type(uint256).max amount

Vulnerability Details

CapitalPool has the next function with hardcoded value for approval:

function approve(address tokenAddr) external {
address tokenManager = tadleFactory.relatedContracts(
RelatedContractLibraries.TOKEN_MANAGER
);
(bool success, ) = tokenAddr.call(
abi.encodeWithSelector(
APPROVE_SELECTOR,
tokenManager,
@> type(uint256).max
)
);
​
if (!success) {
revert ApproveFailed();
}
}

Some tokens, like UNI or COMP will revert on such approves, as they support only type(uint96).max value for it.

Impact

Tokens that don't support approve type(uint256).max amount could not be used by CapitalPool contract.

Tools Used

Manual review

Recommendations

Provide an additional argument for the approval value for that function to make it work with different tokens.

Updates

Lead Judging Commences

0xnevi Lead Judge about 1 year ago
Submission Judgement Published
Validated
Assigned finding tags:

[invalid] finding-CapitalPool-approve-uint256-max

Thanks for flagging, indeed since uint(-1) is representative of max uint256 value, when entering the `if` statement, it will be converted to uint96 max amout, so it will not revert as described. In issue #361, the mockToken utilized does not correctly reflect the below approval behavior. ```Solidity function approve(address spender, uint rawAmount) external returns (bool) { uint96 amount; if (rawAmount == uint(-1)) { amount = uint96(-1); } else { amount = safe96(rawAmount, "Comp::approve: amount exceeds 96 bits"); } ```

Appeal created

kiteweb3 Judge
about 1 year ago
0xnevi Lead Judge
about 1 year ago
0xnevi Lead Judge about 1 year ago
Submission Judgement Published
Invalidated
Reason: Incorrect statement
Assigned finding tags:

[invalid] finding-CapitalPool-approve-uint256-max

Thanks for flagging, indeed since uint(-1) is representative of max uint256 value, when entering the `if` statement, it will be converted to uint96 max amout, so it will not revert as described. In issue #361, the mockToken utilized does not correctly reflect the below approval behavior. ```Solidity function approve(address spender, uint rawAmount) external returns (bool) { uint96 amount; if (rawAmount == uint(-1)) { amount = uint96(-1); } else { amount = safe96(rawAmount, "Comp::approve: amount exceeds 96 bits"); } ```

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