diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp
index d625e5a0..9555318a 100644
--- a/src/blockchain_db/lmdb/db_lmdb.cpp
+++ b/src/blockchain_db/lmdb/db_lmdb.cpp
@@ -130,13 +130,16 @@ private:
 template<>
 struct MDB_val_copy<const char*>: public MDB_val
 {
-  MDB_val_copy(const char *s) :
-    data(strdup(s))
+  MDB_val_copy(const char *s):
+    size(strlen(s)+1), // include the NUL, makes it easier for compares
+    data(new char[size])
   {
-    mv_size = strlen(s) + 1; // include the NUL, makes it easier for compares
+    mv_size = size;
     mv_data = data.get();
+    memcpy(mv_data, s, size);
   }
 private:
+  size_t size;
   std::unique_ptr<char[]> data;
 };
 
@@ -923,6 +926,8 @@ BlockchainLMDB::~BlockchainLMDB()
   // batch transaction shouldn't be active at this point. If it is, consider it aborted.
   if (m_batch_active)
     batch_abort();
+  if (m_open)
+    close();
 }
 
 BlockchainLMDB::BlockchainLMDB(bool batch_transactions)
@@ -1153,6 +1158,7 @@ void BlockchainLMDB::close()
 
   // FIXME: not yet thread safe!!!  Use with care.
   mdb_env_close(m_env);
+  m_open = false;
 }
 
 void BlockchainLMDB::sync()
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index feb31f2f..141a42f4 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -2109,6 +2109,7 @@ bool Blockchain::check_tx_inputs(const transaction& tx, uint64_t* pmax_used_bloc
     if(have_tx_keyimg_as_spent(in_to_key.k_image))
     {
       LOG_PRINT_L1("Key image already spent in blockchain: " << epee::string_tools::pod_to_hex(in_to_key.k_image));
+      KILL_IOSERVICE();
       return false;
     }
 
@@ -2122,6 +2123,7 @@ bool Blockchain::check_tx_inputs(const transaction& tx, uint64_t* pmax_used_bloc
       if(!itk->second)
       {
         LOG_PRINT_L1("Failed ring signature for tx " << get_transaction_hash(tx) << "  vin key with k_image: " << in_to_key.k_image << "  sig_index: " << sig_index);
+        KILL_IOSERVICE();
         return false;
       }