From 5cec076e130f4ae2d1b704086715d59625358feb Mon Sep 17 00:00:00 2001
From: moneromooo-monero <moneromooo-monero@users.noreply.github.com>
Date: Fri, 25 Dec 2015 22:01:21 +0000
Subject: [PATCH] blockchain: add a missing validity check to
 rollback_blockchain_switching

It was present in the original code
---
 src/cryptonote_core/blockchain.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 64b7a5b2..f3111a96 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -717,6 +717,12 @@ bool Blockchain::rollback_blockchain_switching(std::list<block>& original_chain,
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
+  // fail if rollback_height passed is too high
+  if (rollback_height > m_db->height())
+  {
+    return true;
+  }
+
   m_timestamps_and_difficulties_height = 0;
 
   // remove blocks from blockchain until we get back to where we should be.