From 495692c9db3c296485ab75a8d69ba1323f0e4553 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 11:12:26 +0300
Subject: [PATCH] core, eth/downloader, params: validate blob tx bodies
 (#27392)

---
 core/block_validator.go   | 16 ++++++++++++++++
 eth/downloader/queue.go   | 16 ++++++++++++++++
 params/protocol_params.go |  1 +
 3 files changed, 33 insertions(+)

diff --git a/core/block_validator.go b/core/block_validator.go
index ce3e6560ee..6dc9a3fa05 100644
--- a/core/block_validator.go
+++ b/core/block_validator.go
@@ -84,7 +84,23 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 	// Blob transactions may be present after the Cancun fork.
 	var blobs int
 	for _, tx := range block.Transactions() {
+		// Count the number of blobs to validate against the header's dataGasUsed
 		blobs += len(tx.BlobHashes())
+
+		// 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")
+			}
+			for _, hash := range tx.BlobHashes() {
+				if hash[0] != params.BlobTxHashVersion {
+					return fmt.Errorf("blob hash version mismatch (have %d, supported %d)", hash[0], params.BlobTxHashVersion)
+				}
+			}
+		}
 	}
 	if header.DataGasUsed != nil {
 		if want := *header.DataGasUsed / params.BlobTxDataGasPerBlob; uint64(blobs) != want { // div because the header is surely good vs the body might be bloated
diff --git a/eth/downloader/queue.go b/eth/downloader/queue.go
index 0a00d48901..25449d8772 100644
--- a/eth/downloader/queue.go
+++ b/eth/downloader/queue.go
@@ -801,7 +801,23 @@ func (q *queue) DeliverBodies(id string, txLists [][]*types.Transaction, txListH
 		// and zero before the Cancun hardfork
 		var blobs int
 		for _, tx := range txLists[index] {
+			// Count the number of blobs to validate against the header's dataGasUsed
 			blobs += len(tx.BlobHashes())
+
+			// 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
+				}
+				for _, hash := range tx.BlobHashes() {
+					if hash[0] != params.BlobTxHashVersion {
+						return errInvalidBody
+					}
+				}
+			}
 		}
 		if header.DataGasUsed != nil {
 			if want := *header.DataGasUsed / params.BlobTxDataGasPerBlob; uint64(blobs) != want { // div because the header is surely good vs the body might be bloated
diff --git a/params/protocol_params.go b/params/protocol_params.go
index 5ddc13c63b..0b4413f409 100644
--- a/params/protocol_params.go
+++ b/params/protocol_params.go
@@ -160,6 +160,7 @@ const (
 	RefundQuotient        uint64 = 2
 	RefundQuotientEIP3529 uint64 = 5
 
+	BlobTxHashVersion                = 0x01    // Version byte of the commitment hash
 	BlobTxMaxDataGasPerBlock         = 1 << 19 // Maximum consumable data gas for data blobs per block
 	BlobTxTargetDataGasPerBlock      = 1 << 18 // Target consumable data gas for data blobs per block (for 1559-like pricing)
 	BlobTxDataGasPerBlob             = 1 << 17 // Gas consumption of a single data blob (== blob byte size)