Fix missing lock in submitblock

Rebased-From: eb63bf86cf6dc99f150574463df6ffb013a34493
Github-Pull: #6007

1 files changed, 14 insertions, 9 deletions

diff --git a/src/rpcmining.cpp b/src/rpcmining.cpp
index 86230521ce..37465eedd0 100644
--- a/src/rpcmining.cpp
+++ b/src/rpcmining.cpp
@@ -637,14 +637,19 @@ Value submitblock(const Array& params, bool fHelp)
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "Block decode failed");
 
     uint256 hash = block.GetHash();
-    BlockMap::iterator mi = mapBlockIndex.find(hash);
-    if (mi != mapBlockIndex.end()) {
-        CBlockIndex *pindex = mi->second;
-        if (pindex->IsValid(BLOCK_VALID_SCRIPTS))
-            return "duplicate";
-        if (pindex->nStatus & BLOCK_FAILED_MASK)
-            return "duplicate-invalid";
-        // Otherwise, we might only have the header - process the block before returning
+    bool fBlockPresent = false;
+    {
+        LOCK(cs_main);
+        BlockMap::iterator mi = mapBlockIndex.find(hash);
+        if (mi != mapBlockIndex.end()) {
+            CBlockIndex *pindex = mi->second;
+            if (pindex->IsValid(BLOCK_VALID_SCRIPTS))
+                return "duplicate";
+            if (pindex->nStatus & BLOCK_FAILED_MASK)
+                return "duplicate-invalid";
+            // Otherwise, we might only have the header - process the block before returning
+            fBlockPresent = true;
+        }
     }
 
     CValidationState state;
@@ -652,7 +657,7 @@ Value submitblock(const Array& params, bool fHelp)
     RegisterValidationInterface(&sc);
     bool fAccepted = ProcessNewBlock(state, NULL, &block);
     UnregisterValidationInterface(&sc);
-    if (mi != mapBlockIndex.end())
+    if (fBlockPresent)
     {
         if (fAccepted && !sc.found)
             return "duplicate-inconclusive";