Beedle - Oracle free perpetual lending

Summary

Pool lender should be able to still sell the loan even after auctionLength has passed.

Vulnerability Details

In some cases where the loan principal will be of pretty close value to the collateral, the lender might prefer receiving the loanToken, despite the collateral being a bit higher in value (e.g. needs specific token and to avoid swapping fees later). If there's another pool lender who has just found out about the loan auction after it has finished, they should still be able to buyLoan as this will give value to both parties.
Furthermore, this becomes even bigger of a problem combined with the fact that upon buyLoan and giveLoan the auctionLength doesn't change. The pool lender auctioning the loan, could've taken the loan from another pool with significantly lower auctionLength and because of it they may end up not being able to sell the loan.

Impact

Loss of value for a loan buyer and a loan seller

Tools Used

Manual review

Recommendations

User's should be able to buyLoan even after auctionLength has passed.