From 7dc5e785a8fda2485515203c302fdd113dd5313e Mon Sep 17 00:00:00 2001
From: yihuang <huang@crypto.com>
Date: Wed, 9 Nov 2022 14:52:13 +0800
Subject: [PATCH] core/vm: deepcopy jumptable when enabling extra eips (#26137)

When the interpreter is configured to use extra-eips, this change makes it so that all the opcodes are deep-copied, to prevent accidental modification of the 'base' jumptable.

Closes: #26136

Co-authored-by: Martin Holst Swende <martin@swende.se>
---
 core/vm/interpreter.go     |  8 +++++---
 core/vm/jump_table.go      | 11 +++++++++++
 core/vm/jump_table_test.go | 35 +++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+), 3 deletions(-)
 create mode 100644 core/vm/jump_table_test.go

diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index 312977b755..c99e54b76d 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -82,15 +82,17 @@ func NewEVMInterpreter(evm *EVM, cfg Config) *EVMInterpreter {
 			cfg.JumpTable = &frontierInstructionSet
 		}
 		var extraEips []int
+		if len(cfg.ExtraEips) > 0 {
+			// Deep-copy jumptable to prevent modification of opcodes in other tables
+			cfg.JumpTable = copyJumpTable(cfg.JumpTable)
+		}
 		for _, eip := range cfg.ExtraEips {
-			copy := *cfg.JumpTable
-			if err := EnableEIP(eip, &copy); err != nil {
+			if err := EnableEIP(eip, cfg.JumpTable); err != nil {
 				// Disable it, so caller can check if it's activated or not
 				log.Error("EIP activation failed", "eip", eip, "error", err)
 			} else {
 				extraEips = append(extraEips, eip)
 			}
-			cfg.JumpTable = &copy
 		}
 		cfg.ExtraEips = extraEips
 	}
diff --git a/core/vm/jump_table.go b/core/vm/jump_table.go
index 94229436d2..7cbcc56c5a 100644
--- a/core/vm/jump_table.go
+++ b/core/vm/jump_table.go
@@ -1043,3 +1043,14 @@ func newFrontierInstructionSet() JumpTable {
 
 	return validate(tbl)
 }
+
+func copyJumpTable(source *JumpTable) *JumpTable {
+	dest := *source
+	for i, op := range source {
+		if op != nil {
+			opCopy := *op
+			dest[i] = &opCopy
+		}
+	}
+	return &dest
+}
diff --git a/core/vm/jump_table_test.go b/core/vm/jump_table_test.go
new file mode 100644
index 0000000000..f67915fff3
--- /dev/null
+++ b/core/vm/jump_table_test.go
@@ -0,0 +1,35 @@
+// Copyright 2022 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package vm
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+// TestJumpTableCopy tests that deep copy is necessery to prevent modify shared jump table
+func TestJumpTableCopy(t *testing.T) {
+	tbl := newMergeInstructionSet()
+	require.Equal(t, uint64(0), tbl[SLOAD].constantGas)
+
+	// a deep copy won't modify the shared jump table
+	deepCopy := copyJumpTable(&tbl)
+	deepCopy[SLOAD].constantGas = 100
+	require.Equal(t, uint64(100), deepCopy[SLOAD].constantGas)
+	require.Equal(t, uint64(0), tbl[SLOAD].constantGas)
+}