From 0eb3a6cdbb1647a2d5bd216a7cd5c529e626a3b4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Wed, 31 May 2023 13:08:15 +0300
Subject: [PATCH] core, eth/downloader: validate blobtx.To at serialization
 time (#27393)

---
 core/block_validator.go               | 3 ---
 core/types/receipt_test.go            | 4 ++--
 core/types/transaction_marshalling.go | 5 +++--
 core/types/tx_blob.go                 | 6 +++---
 eth/downloader/queue.go               | 3 ---
 5 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/core/block_validator.go b/core/block_validator.go
index 6dc9a3fa051a5..1bca444451275 100644
--- a/core/block_validator.go
+++ b/core/block_validator.go
@@ -89,9 +89,6 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 
 		// Validate the data blobs individually too
 		if tx.Type() == types.BlobTxType {
-			if tx.To() == nil {
-				return errors.New("contract creation attempt by blob transaction") // TODO(karalabe): Why not make the field non-nil-able
-			}
 			if len(tx.BlobHashes()) == 0 {
 				return errors.New("no-blob blob transaction present in block body")
 			}
diff --git a/core/types/receipt_test.go b/core/types/receipt_test.go
index 168f36208b9eb..5722eceac13d6 100644
--- a/core/types/receipt_test.go
+++ b/core/types/receipt_test.go
@@ -130,7 +130,7 @@ var (
 		}),
 		// EIP-4844 transactions.
 		NewTx(&BlobTx{
-			To:         &to6,
+			To:         to6,
 			Nonce:      6,
 			Value:      uint256.NewInt(6),
 			Gas:        6,
@@ -139,7 +139,7 @@ var (
 			BlobFeeCap: uint256.NewInt(100066),
 		}),
 		NewTx(&BlobTx{
-			To:         &to7,
+			To:         to7,
 			Nonce:      7,
 			Value:      uint256.NewInt(7),
 			Gas:        7,
diff --git a/core/types/transaction_marshalling.go b/core/types/transaction_marshalling.go
index 6c6c50d498d72..070927484cc7c 100644
--- a/core/types/transaction_marshalling.go
+++ b/core/types/transaction_marshalling.go
@@ -290,9 +290,10 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 			return errors.New("missing required field 'nonce' in transaction")
 		}
 		itx.Nonce = uint64(*dec.Nonce)
-		if dec.To != nil {
-			itx.To = dec.To
+		if dec.To == nil {
+			return errors.New("missing required field 'to' in transaction")
 		}
+		itx.To = *dec.To
 		if dec.Gas == nil {
 			return errors.New("missing required field 'gas' for txdata")
 		}
diff --git a/core/types/tx_blob.go b/core/types/tx_blob.go
index 58065d0017d31..34c01ee014c3a 100644
--- a/core/types/tx_blob.go
+++ b/core/types/tx_blob.go
@@ -31,7 +31,7 @@ type BlobTx struct {
 	GasTipCap  *uint256.Int // a.k.a. maxPriorityFeePerGas
 	GasFeeCap  *uint256.Int // a.k.a. maxFeePerGas
 	Gas        uint64
-	To         *common.Address `rlp:"nil"` // nil means contract creation
+	To         common.Address
 	Value      *uint256.Int
 	Data       []byte
 	AccessList AccessList
@@ -48,7 +48,7 @@ type BlobTx struct {
 func (tx *BlobTx) copy() TxData {
 	cpy := &BlobTx{
 		Nonce: tx.Nonce,
-		To:    copyAddressPtr(tx.To),
+		To:    tx.To,
 		Data:  common.CopyBytes(tx.Data),
 		Gas:   tx.Gas,
 		// These are copied below.
@@ -104,7 +104,7 @@ func (tx *BlobTx) gasTipCap() *big.Int       { return tx.GasTipCap.ToBig() }
 func (tx *BlobTx) gasPrice() *big.Int        { return tx.GasFeeCap.ToBig() }
 func (tx *BlobTx) value() *big.Int           { return tx.Value.ToBig() }
 func (tx *BlobTx) nonce() uint64             { return tx.Nonce }
-func (tx *BlobTx) to() *common.Address       { return tx.To }
+func (tx *BlobTx) to() *common.Address       { tmp := tx.To; return &tmp }
 func (tx *BlobTx) blobGas() uint64           { return params.BlobTxDataGasPerBlob * uint64(len(tx.BlobHashes)) }
 func (tx *BlobTx) blobGasFeeCap() *big.Int   { return tx.BlobFeeCap.ToBig() }
 func (tx *BlobTx) blobHashes() []common.Hash { return tx.BlobHashes }
diff --git a/eth/downloader/queue.go b/eth/downloader/queue.go
index 25449d87724b2..8c82d7f072d0d 100644
--- a/eth/downloader/queue.go
+++ b/eth/downloader/queue.go
@@ -806,9 +806,6 @@ func (q *queue) DeliverBodies(id string, txLists [][]*types.Transaction, txListH
 
 			// Validate the data blobs individually too
 			if tx.Type() == types.BlobTxType {
-				if tx.To() == nil {
-					return errInvalidBody // TODO(karalabe): Why not make the field non-nil-able
-				}
 				if len(tx.BlobHashes()) == 0 {
 					return errInvalidBody
 				}