consensus: require CBlockIndex::GetUndoPos() to hold mutex cs_main

bitcoin · Sep 17, 2021 · e950f0e · e950f0e
1 parent b82ad98
commit e950f0e
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/src/chain.h b/src/chain.h
@@ -225,7 +225,8 @@ class CBlockIndex
         return ret;
     }
 
-    FlatFilePos GetUndoPos() const {
+    FlatFilePos GetUndoPos() const EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+    {
         FlatFilePos ret;
         if (nStatus & BLOCK_HAVE_UNDO) {
             ret.nFile = nFile;

diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
@@ -136,7 +136,8 @@ static bool UndoWriteToDisk(const CBlockUndo& blockundo, FlatFilePos& pos, const
 
 bool UndoReadFromDisk(CBlockUndo& blockundo, const CBlockIndex* pindex)
 {
-    FlatFilePos pos = pindex->GetUndoPos();
+    const FlatFilePos pos{WITH_LOCK(cs_main, return pindex->GetUndoPos())};
+
     if (pos.IsNull()) {
         return error("%s: no undo data available", __func__);
     }
@@ -336,7 +337,7 @@ static bool WriteBlockToDisk(const CBlock& block, FlatFilePos& pos, const CMessa
 bool WriteUndoDataForBlock(const CBlockUndo& blockundo, BlockValidationState& state, CBlockIndex* pindex, const CChainParams& chainparams)
 {
     // Write undo information to disk
-    if (pindex->GetUndoPos().IsNull()) {
+    if (WITH_LOCK(cs_main, return pindex->GetUndoPos()).IsNull()) {
         FlatFilePos _pos;
         if (!FindUndoPos(state, pindex->nFile, _pos, ::GetSerializeSize(blockundo, CLIENT_VERSION) + 40)) {
             return error("ConnectBlock(): FindUndoPos failed");