fix(evm): ensure stateDB is nil after tx execution

CHANGELOG.md

@@ -84,7 +84,8 @@ needed to include double quotes around the hexadecimal string.
 - [#2169](https://github.com/NibiruChain/nibiru/pull/2169) - fix(evm): Better handling erc20 metadata
 - [#2170](https://github.com/NibiruChain/nibiru/pull/2170) - chore: Remove redundant allowUnprotectedTxs
 - [#2172](https://github.com/NibiruChain/nibiru/pull/2172) - chore: close iterator in IterateEpochInfo
-- 
+- [#2173](https://github.com/NibiruChain/nibiru/pull/2173) - fix(evm): clear `StateDB` between calls
+
 #### Nibiru EVM | Before Audit 2 - 2024-12-06
 
 The codebase went through a third-party [Code4rena

x/evm/keeper/funtoken_from_coin.go

@@ -98,6 +98,9 @@ func (k *Keeper) deployERC20ForBankCoin(
 	if stateDB == nil {
 		stateDB = k.NewStateDB(ctx, txConfig)
 	}
+	defer func() {
+		k.Bank.StateDB = nil
+	}()
 	evmObj := k.NewEVM(ctx, evmMsg, evmCfg, nil /*tracer*/, stateDB)
 	evmResp, err := k.CallContractWithInput(
 		ctx, evmObj, evm.EVM_MODULE_ADDRESS, nil, true /*commit*/, input, Erc20GasLimitDeploy,
@@ -110,8 +113,6 @@ func (k *Keeper) deployERC20ForBankCoin(
 	if err != nil {
 		return gethcommon.Address{}, errors.Wrap(err, "failed to commit stateDB")
 	}
-	// Don't need the StateDB anymore because it's not usable after committing
-	k.Bank.StateDB = nil
 
 	ctx.GasMeter().ConsumeGas(evmResp.GasUsed, "deploy erc20 funtoken contract")
 

x/evm/keeper/funtoken_from_erc20.go

@@ -132,6 +132,9 @@ func (k *Keeper) createFunTokenFromERC20(
 	if stateDB == nil {
 		stateDB = k.NewStateDB(ctx, statedb.NewEmptyTxConfig(gethcommon.BytesToHash(ctx.HeaderHash())))
 	}
+	defer func() {
+		k.Bank.StateDB = nil
+	}()
 	evmMsg := gethcore.NewMessage(
 		evm.EVM_MODULE_ADDRESS,
 		&erc20,
@@ -184,8 +187,6 @@ func (k *Keeper) createFunTokenFromERC20(
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to commit stateDB")
 	}
-	// Don't need the StateDB anymore because it's not usable after committing
-	k.Bank.StateDB = nil
 
 	return funtoken, k.FunTokens.SafeInsert(
 		ctx, erc20, bankDenom, false,

x/evm/keeper/msg_server.go

@@ -60,6 +60,9 @@ func (k *Keeper) EthereumTx(
 	if stateDB == nil {
 		stateDB = k.NewStateDB(ctx, txConfig)
 	}
+	defer func() {
+		k.Bank.StateDB = nil
+	}()
 	evmObj := k.NewEVM(ctx, evmMsg, evmCfg, nil /*tracer*/, stateDB)
 	evmResp, err = k.ApplyEvmMsg(ctx, evmMsg, evmObj, nil /*tracer*/, true /*commit*/, txConfig.TxHash, false /*fullRefundLeftoverGas*/)
 	if err != nil {
@@ -341,8 +344,6 @@ func (k *Keeper) ApplyEvmMsg(
 		if err := evmObj.StateDB.(*statedb.StateDB).Commit(); err != nil {
 			return nil, errors.Wrap(err, "ApplyEvmMsg: failed to commit stateDB")
 		}
-		// after we commit, the StateDB is no longer usable so we discard it and let the Golang garbage collector dispose of it
-		k.Bank.StateDB = nil
 	}
 	// Rare case of uint64 gas overflow
 	if msg.Gas() < leftoverGas {
@@ -544,10 +545,13 @@ func (k Keeper) convertCoinToEvmBornCoin(
 		true,
 	)
 	txConfig := k.TxConfig(ctx, gethcommon.Hash{})
-	var stateDB *statedb.StateDB = k.Bank.StateDB
+	stateDB := k.Bank.StateDB
 	if stateDB == nil {
 		stateDB = k.NewStateDB(ctx, txConfig)
 	}
+	defer func() {
+		k.Bank.StateDB = nil
+	}()
 	evmObj := k.NewEVM(ctx, evmMsg, k.GetEVMConfig(ctx), nil /*tracer*/, stateDB)
 	evmResp, err := k.CallContractWithInput(
 		ctx,
@@ -572,7 +576,6 @@ func (k Keeper) convertCoinToEvmBornCoin(
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to commit stateDB")
 	}
-	k.Bank.StateDB = nil
 
 	_ = ctx.EventManager().EmitTypedEvent(&evm.EventConvertCoinToEvm{
 		Sender:               sender.String(),
@@ -596,10 +599,13 @@ func (k Keeper) convertCoinToEvmBornERC20(
 	funTokenMapping evm.FunToken,
 ) (*evm.MsgConvertCoinToEvmResponse, error) {
 	// needs to run first to populate the StateDB on the BankKeeperExtension
-	var stateDB *statedb.StateDB = k.Bank.StateDB
+	stateDB := k.Bank.StateDB
 	if stateDB == nil {
 		stateDB = k.NewStateDB(ctx, k.TxConfig(ctx, gethcommon.Hash{}))
 	}
+	defer func() {
+		k.Bank.StateDB = nil
+	}()
 
 	erc20Addr := funTokenMapping.Erc20Addr.Address
 	// 1 | Caller transfers Bank Coins to be converted to ERC20 tokens.
@@ -664,7 +670,6 @@ func (k Keeper) convertCoinToEvmBornERC20(
 	if err := stateDB.Commit(); err != nil {
 		return nil, errors.Wrap(err, "failed to commit stateDB")
 	}
-	k.Bank.StateDB = nil
 
 	// Emit event with the actual amount received
 	_ = ctx.EventManager().EmitTypedEvent(&evm.EventConvertCoinToEvm{

x/evm/precompile/funtoken.go

@@ -59,7 +59,6 @@ func (p precompileFunToken) Run(
 	if err != nil {
 		return nil, err
 	}
-	p.evmKeeper.Bank.StateDB = startResult.StateDB
 
 	// Gracefully handles "out of gas"
 	defer HandleOutOfGasPanic(&err)()

x/evm/precompile/wasm.go

@@ -48,11 +48,6 @@ func (p precompileWasm) Run(
 
 	abciEventsStartIdx := len(startResult.CacheCtx.EventManager().Events())
 
-	// NOTE: The NibiruBankKeeper needs to reference the current [vm.StateDB] before
-	// any operation that has the potential to use Bank send methods. This will
-	// guarantee that [evmkeeper.Keeper.SetAccBalance] journal changes are
-	// recorded if wei (NIBI) is transferred.
-	p.Bank.StateDB = startResult.StateDB
 	switch PrecompileMethod(startResult.Method.Name) {
 	case WasmMethod_execute:
 		bz, err = p.execute(startResult, contract.CallerAddress, readonly)