From 02de6a6bcda8bef4c35eb6c5135529fdf51f0f88 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Barbosa?= <joao.paulo.barbosa@gmail.com>
Date: Thu, 11 Jan 2018 23:32:32 +0000
Subject: [PATCH] Assert cs_main is held when accessing mapBlockIndex

---
 src/validation.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/validation.cpp b/src/validation.cpp
index a77362f5d6..18412d9e94 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -260,6 +260,8 @@ namespace {
 
 CBlockIndex* FindForkInGlobalIndex(const CChain& chain, const CBlockLocator& locator)
 {
+    AssertLockHeld(cs_main);
+
     // Find the first block the caller has in the main chain
     for (const uint256& hash : locator.vHave) {
         BlockMap::iterator mi = mapBlockIndex.find(hash);
@@ -2774,6 +2776,8 @@ bool ResetBlockFailureFlags(CBlockIndex *pindex) {
 
 CBlockIndex* CChainState::AddToBlockIndex(const CBlockHeader& block)
 {
+    AssertLockHeld(cs_main);
+
     // Check for duplicate
     uint256 hash = block.GetHash();
     BlockMap::iterator it = mapBlockIndex.find(hash);
@@ -3654,6 +3658,8 @@ fs::path GetBlockPosFilename(const CDiskBlockPos &pos, const char *prefix)
 
 CBlockIndex * CChainState::InsertBlockIndex(const uint256& hash)
 {
+    AssertLockHeld(cs_main);
+
     if (hash.IsNull())
         return nullptr;
 
@@ -3781,6 +3787,8 @@ bool static LoadBlockIndexDB(const CChainParams& chainparams)
 
 bool LoadChainTip(const CChainParams& chainparams)
 {
+    AssertLockHeld(cs_main);
+
     if (chainActive.Tip() && chainActive.Tip()->GetBlockHash() == pcoinsTip->GetBestBlock()) return true;
 
     if (pcoinsTip->GetBestBlock().IsNull() && mapBlockIndex.size() == 1) {