s1ce - OpenRelay payment doesn't include L1 Data fees

[sherlock-admin4]

s1ce

high

OpenRelay payment doesn't include L1 Data fees

Summary

Keepers will be undercompensated on L2s, such as Optimism or Blast, because the payment calculation does not include L1 Data fees

Vulnerability Detail

There are two types of gas fees on L2s: The L2 execution fees and the L1 Data fees. The current formula, which multiplies the block base fee times the gas used, only takes into account the execution fees. The L1 Data fees can potentially be costly and are not included as part of this calculation, so keepers could be undercompensated for their transactions as a result.

The error is in this computation:

    uint256 _initialGas = gasleft();
    _automationVault.exec(msg.sender, _execData, new IAutomationVault.FeeData[](0));
    uint256 _gasSpent = _initialGas - gasleft();

    // Calculate the payment for the relayer
    uint256 _payment = (_gasSpent + GAS_BONUS) * block.basefee * GAS_MULTIPLIER / BASE;

Impact

Keepers could be undercompensated

Code Snippet

https://github.com/sherlock-audit/2024-04-xkeeper/blob/main/xkeeper-core/solidity/contracts/relays/OpenRelay.sol#L29

Tool used

Manual Review

Recommendation

Account for L1 Data Fee

Duplicate of #57

[s1ce]

Escalate

Not sure why this was excluded. Duplicate of #57

[sherlock-admin2]

Escalate

Not sure why this was excluded. Duplicate of #57

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[Hash01011122]

Agreed this is indeed duplicate of #57

[cvetanovv]

I agree it is a duplicate of #57.

Planning to accept the escalation and duplicate with #57.

[Evert0x]

Result:
Medium
Duplicate of #57

[sherlock-admin2]

Escalations have been resolved successfully!

Escalation status:

• s1ce: accepted