[evm] feat/security: Consume the full gas limit of a failed signing.Tx in the case it has multiple EthereumTx messages

[Unique-Divine]

Context

Note

Non-blocking for Nibiru V2 on mainnet

Originally posted by @Unique-Divine in #4

I think this works as a nice-to-have feature ticket but wouldn't consider it a blocker for launch. We can work on this later and put it in one of the upgrades post v2.0

Original Ticket

Target

nibiru/x/evm/keeper/msg_server.go

Lines 64 to 67 in 13c71a7

	evmResp, err = k.ApplyEvmMsg(ctx, evmMsg, evmObj, nil /*tracer*/, true /*commit*/, txConfig.TxHash, false /*fullRefundLeftoverGas*/)
	if err != nil {
	return nil, errors.Wrap(err, "error applying ethereum core message")
	}

Severity:

• Impact: Low
• Likelihood: Medium

Description:

In EthereumTx(..), which handles the MsgEthereumTx message, if a Cosmos tx contains a batch of multiple MsgEthereumTx EVM messages, and one of it errors in ApplyEvmMsg(..) (i.e., err != nil), the full gas limit (e.g. ctx.GasMeter().GasLimit()) is not consumed. This also differs from Ethereum, where all gas is consumed in case of an unexpected error.

64: 	evmResp, err = k.ApplyEvmMsg(ctx, evmMsg, evmObj, nil /*tracer*/, true /*commit*/, txConfig.TxHash, false /*fullRefundLeftoverGas*/)
65: 	if err != nil {
66: 		return nil, errors.Wrap(err, "error applying ethereum core message")
67: 	}

Recommendation:

Consume all of the remaining and unused Cosmos tx's gas limit.