fees calculations are not accurate

[code423n4]

Handle

certora

Vulnerability details

after that fee is calculated, it is minted to the feeBeneficiary.
simply minting the exact amount results lower fee than it should be.

Impact

feeBeneficiary will get less fees than it should.

Proof of Concept

let's assume that the basket assets are worth 1M dollars, and totalSupply = 1M.
the result of calcOutStandingAnnualizedFee is 100,00 so the feeBeneficiary should get 100,00 dollars.
however, when minting 100,00 the totalSupply will increase to 1,100,000 so they will own 100000/1100000* (1M dollars) = 90909.09 dollars instead of 100k

[loki-sama]

This is mitigated by the feeBeneficiary diluting his own shares if he gets fees on his fees.

[0xleastwood]

I'm not exactly sure if I understand what the warden is stating here. Could you confirm @loki-sama ?

[loki-sama]

Ok, I myself misunderstood. He is correct that we don't get the full value. When we take a fee of 10% like from his example. What we do is mint 10% of the basket to ourselves. That 10% after minting is not holding 10% of the underling.