From c39c66fb9c1b10fa3021893255e0b5b10f403f67 Mon Sep 17 00:00:00 2001
From: Pratik Patil <pratikspatil024@gmail.com>
Date: Thu, 11 May 2023 12:20:58 +0530
Subject: [PATCH] Added check for circular and out-of-range dependency problem
 (#841)

* added check for circular and out-of-range dependency problem

* addressed comment

* addressed comments
---
 core/parallel_state_processor.go | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/core/parallel_state_processor.go b/core/parallel_state_processor.go
index 9eb56c766f..e72fb4e6d8 100644
--- a/core/parallel_state_processor.go
+++ b/core/parallel_state_processor.go
@@ -290,6 +290,11 @@ func (p *ParallelStateProcessor) Process(block *types.Block, statedb *state.Stat
 
 	if block.Header().TxDependency != nil {
 		metadata = true
+
+		if !VerifyDeps(deps) {
+			metadata = false
+			deps = GetDeps([][]uint64{})
+		}
 	}
 
 	blockContext := NewEVMBlockContext(header, p.bc, nil)
@@ -431,3 +436,20 @@ func GetDeps(txDependency [][]uint64) map[int][]int {
 
 	return deps
 }
+
+// returns true if dependencies are correct
+func VerifyDeps(deps map[int][]int) bool {
+	// number of transactions in the block
+	n := len(deps)
+
+	// Handle out-of-range and circular dependency problem
+	for tx, val := range deps {
+		for depTx := range val {
+			if depTx >= n || depTx < tx {
+				return false
+			}
+		}
+	}
+
+	return true
+}