Careful with uint8

[gpersoon]

Vulnerability details

Note: the current version of GeneralConvexStrategy.sol doesn't compile as far as I can see.

using SafeMath for uint8; ==> could lead to using uint8.

Using uint8 might lead to overflows. The Solidity compiler 6.12 gives the following warning when doing 10**uint8variable:

Warning: Result of exponentiation has type uint8 and thus might overflow. 

Luckily because balances(..) is an uint256 the code of getMostPremium() doesn't go wrong.

Proof of concept

metavault/contracts/v3/strategies/GeneralConvexStrategy.sol

Line 14 in 8f35c3d

using SafeMath for uint8;

metavault/contracts/v3/strategies/GeneralConvexStrategy.sol

Lines 107 to 110 in 8f35c3d

	function getMostPremium() public view returns (address, uint256) {
	uint256 balance0 = IStableSwap3Pool(stableSwapPool).balances(0).mul(
	10**(decimalMultiples[0])
	);

Recommended mitigation steps

replace:

• using SafeMath for uint8;

with:

• using SafeMath for uint;

And use typecasts to change uint8 to uint256 before doing non-trivial calculations:

uint256 balance0 = IStableSwap3Pool(stableSwapPool).balances(0).mul(10**uint256(decimalMultiples[0]));