Require CBlockIndex::RaiseValidity() to hold cs_main

src/chain.h

@@ -328,8 +328,9 @@ public:
 
     //! Raise the validity level of this block index entry.
     //! Returns true if the validity was changed.
-    bool RaiseValidity(enum BlockStatus nUpTo)
+    bool RaiseValidity(enum BlockStatus nUpTo) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
     {
+        AssertLockHeld(::cs_main);
         assert(!(nUpTo & ~BLOCK_VALID_MASK)); // Only validity flags allowed.
         if (nStatus & BLOCK_FAILED_MASK) return false;
 

src/test/fuzz/chain.cpp

@@ -58,7 +58,7 @@ FUZZ_TARGET(chain)
         if (block_status & ~BLOCK_VALID_MASK) {
             continue;
         }
-        (void)disk_block_index->RaiseValidity(block_status);
+        WITH_LOCK(::cs_main, (void)disk_block_index->RaiseValidity(block_status));
     }
 
     CBlockIndex block_index{block_header};