From 94d55be6faa3655b141ead6159da0705bf41c80a Mon Sep 17 00:00:00 2001
From: Michael Sproul <michael@sigmaprime.io>
Date: Fri, 5 Jul 2024 14:30:15 +1000
Subject: [PATCH] Increase penalty for old block gossip spam (#6050)

* Increase penalty for old block gossip spam
---
 .../gossip_methods.rs                         | 30 +++++++++++++++----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/beacon_node/network/src/network_beacon_processor/gossip_methods.rs b/beacon_node/network/src/network_beacon_processor/gossip_methods.rs
index 07173f2416..ab25053258 100644
--- a/beacon_node/network/src/network_beacon_processor/gossip_methods.rs
+++ b/beacon_node/network/src/network_beacon_processor/gossip_methods.rs
@@ -1012,11 +1012,12 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
                 self.propagate_validation_result(message_id, peer_id, MessageAcceptance::Ignore);
                 return None;
             }
-            Err(e @ BlockError::FutureSlot { .. })
-            | Err(e @ BlockError::WouldRevertFinalizedSlot { .. })
-            | Err(e @ BlockError::NotFinalizedDescendant { .. }) => {
-                debug!(self.log, "Could not verify block for gossip. Ignoring the block";
-                            "error" => %e);
+            Err(e @ BlockError::FutureSlot { .. }) => {
+                debug!(
+                    self.log,
+                    "Could not verify block for gossip. Ignoring the block";
+                    "error" => %e
+                );
                 // Prevent recurring behaviour by penalizing the peer slightly.
                 self.gossip_penalize_peer(
                     peer_id,
@@ -1026,6 +1027,25 @@ impl<T: BeaconChainTypes> NetworkBeaconProcessor<T> {
                 self.propagate_validation_result(message_id, peer_id, MessageAcceptance::Ignore);
                 return None;
             }
+            Err(e @ BlockError::WouldRevertFinalizedSlot { .. })
+            | Err(e @ BlockError::NotFinalizedDescendant { .. }) => {
+                debug!(
+                    self.log,
+                    "Could not verify block for gossip. Ignoring the block";
+                    "error" => %e
+                );
+                // The spec says we must IGNORE these blocks but there's no reason for an honest
+                // and non-buggy client to be gossiping blocks that blatantly conflict with
+                // finalization. Old versions of Erigon/Caplin are known to gossip pre-finalization
+                // blocks and we want to isolate them to encourage an update.
+                self.gossip_penalize_peer(
+                    peer_id,
+                    PeerAction::LowToleranceError,
+                    "gossip_block_low",
+                );
+                self.propagate_validation_result(message_id, peer_id, MessageAcceptance::Ignore);
+                return None;
+            }
             Err(ref e @ BlockError::ExecutionPayloadError(ref epe)) if !epe.penalize_peer() => {
                 debug!(self.log, "Could not verify block for gossip. Ignoring the block";
                             "error" => %e);