0x52 - safeApprove breaks logic and functions in many locations

[sherlock-admin]

0x52

medium

safeApprove breaks logic and functions in many locations

Summary

safeApprove will revert if there is any leftover allowance. This causes broken logic in many spots.

Periphery#sponsorSeries - full allowance may not be used causing that stake ERC20 to be broken afterwards

Periphery#onBoardAdapter - will fail if the same target is used across multiple different adapters

Periphery/RollerPeriphery#_fillQuote - always approves max which will cause revert on subsequent calls for same token to same spender

Vulnerability Detail

See summary.

Impact

Users will be unable to sponsor series or create adapters with those tokens

Code Snippet

https://github.com/sherlock-audit/2023-03-sense/blob/main/sense-v1/pkg/core/src/Periphery.sol#L128

https://github.com/sherlock-audit/2023-03-sense/blob/main/sense-v1/pkg/core/src/Periphery.sol#L491

https://github.com/sherlock-audit/2023-03-sense/blob/main/sense-v1/pkg/core/src/Periphery.sol#L908

Tool used

Manual Review

Recommendation

Check if current allowance is enough and only increase if needed

[jparklev]

Disputed: This is true on the safeERC20 contract from OZ, but as far as I know, you don't have that restriction on Solmate's one.