From 20db2e7162ffd6a632c8d44c6d25fa1a63f35f68 Mon Sep 17 00:00:00 2001
From: j-berman <justinberman@protonmail.com>
Date: Tue, 4 Aug 2026 13:57:57 -0700
Subject: [PATCH] blockchain: if block is known invalid, fail block
 verification

---
 src/cryptonote_core/blockchain.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 6a902110a..218b94d0e 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -4520,10 +4520,13 @@ bool Blockchain::add_new_block(const block& bl, block_verification_context& bvc,
   CRITICAL_REGION_LOCAL(m_tx_pool);//to avoid deadlock lets lock tx_pool for whole add/reorganize process
   CRITICAL_REGION_LOCAL1(m_blockchain_lock);
   db_rtxn_guard rtxn_guard(m_db);
-  if(have_block(id))
+  int where = 0;
+  if(have_block(id, &where))
   {
     LOG_PRINT_L3("block with id = " << id << " already exists");
     bvc.m_already_exists = true;
+    if (where == HAVE_BLOCK_INVALID)
+      bvc.m_verifivation_failed = true;
     return false;
   }