From 398d860a8ad5defbdbb583c7fbd0a49348e94fec Mon Sep 17 00:00:00 2001
From: Roberto Bayardo <roberto.bayardo@coinbase.com>
Date: Sun, 25 Feb 2024 17:09:24 -0800
Subject: [PATCH] make blobpool reject blob transactions with fee below the
 minimum

---
 core/txpool/blobpool/blobpool_test.go | 18 ++++++++++++++++++
 core/txpool/validation.go             |  7 ++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/core/txpool/blobpool/blobpool_test.go b/core/txpool/blobpool/blobpool_test.go
index be5833011a..f7644c1d0a 100644
--- a/core/txpool/blobpool/blobpool_test.go
+++ b/core/txpool/blobpool/blobpool_test.go
@@ -1228,6 +1228,24 @@ func TestAdd(t *testing.T) {
 				},
 			},
 		},
+		// Blob transactions that don't meet the min blob gas price should be rejected
+		{
+			seeds: map[string]seed{
+				"alice": {balance: 10000000},
+			},
+			adds: []addtx{
+				{ // New account, no previous txs, nonce 0, but blob fee cap too low
+					from: "alice",
+					tx:   makeUnsignedTx(0, 1, 1, 0),
+					err:  txpool.ErrUnderpriced,
+				},
+				{ // Same as above but blob fee cap equals minimum, should be accepted
+					from: "alice",
+					tx:   makeUnsignedTx(0, 1, 1, params.BlobTxMinBlobGasprice),
+					err:  nil,
+				},
+			},
+		},
 	}
 	for i, tt := range tests {
 		// Create a temporary folder for the persistent backend
diff --git a/core/txpool/validation.go b/core/txpool/validation.go
index a9bd14020b..ac52c3f8de 100644
--- a/core/txpool/validation.go
+++ b/core/txpool/validation.go
@@ -108,8 +108,12 @@ func ValidateTransaction(tx *types.Transaction, head *types.Header, signer types
 	if tx.GasTipCapIntCmp(opts.MinTip) < 0 {
 		return fmt.Errorf("%w: tip needed %v, tip permitted %v", ErrUnderpriced, opts.MinTip, tx.GasTipCap())
 	}
-	// Ensure blob transactions have valid commitments
 	if tx.Type() == types.BlobTxType {
+		// Ensure the blob fee cap cap satisfies the minimum blob gas price
+		minBlobGasPrice := big.NewInt(params.BlobTxMinBlobGasprice)
+		if tx.BlobGasFeeCapIntCmp(minBlobGasPrice) < 0 {
+			return fmt.Errorf("%w: blob transaction has too low BlobFeeCap: %v, need: %v", ErrUnderpriced, tx.BlobGasFeeCap(), minBlobGasPrice)
+		}
 		sidecar := tx.BlobTxSidecar()
 		if sidecar == nil {
 			return fmt.Errorf("missing sidecar in blob transaction")
@@ -123,6 +127,7 @@ func ValidateTransaction(tx *types.Transaction, head *types.Header, signer types
 		if len(hashes) > params.MaxBlobGasPerBlock/params.BlobTxBlobGasPerBlob {
 			return fmt.Errorf("too many blobs in transaction: have %d, permitted %d", len(hashes), params.MaxBlobGasPerBlock/params.BlobTxBlobGasPerBlob)
 		}
+		// Ensure commitments, proofs, & hashes are valid
 		if err := validateBlobSidecar(hashes, sidecar); err != nil {
 			return err
 		}