Randomize message processing peer order

1 files changed, 6 insertions, 0 deletions

diff --git a/src/net.cpp b/src/net.cpp
index 6f9f17ed4e..9c6cb379d2 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -2173,6 +2173,7 @@ void CConnman::OpenNetworkConnection(const CAddress& addrConnect, bool fCountFai
 
 void CConnman::ThreadMessageHandler()
 {
+    FastRandomContext rng;
     while (!flagInterruptMsgProc)
     {
         std::vector<CNode*> vNodesCopy;
@@ -2186,6 +2187,11 @@ void CConnman::ThreadMessageHandler()
 
         bool fMoreWork = false;
 
+        // Randomize the order in which we process messages from/to our peers.
+        // This prevents attacks in which an attacker exploits having multiple
+        // consecutive connections in the vNodes list.
+        Shuffle(vNodesCopy.begin(), vNodesCopy.end(), rng);
+
         for (CNode* pnode : vNodesCopy)
         {
             if (pnode->fDisconnect)