From 716f5855406fd02502859f40cbcdd3a1827d7614 Mon Sep 17 00:00:00 2001
From: Lukasz Klimek <842586+lklimek@users.noreply.github.com>
Date: Mon, 12 Aug 2024 12:39:05 +0200
Subject: [PATCH] fix(consensus): vote extensions verified multiple times

---
 internal/consensus/state_add_vote.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/internal/consensus/state_add_vote.go b/internal/consensus/state_add_vote.go
index 284964cbb..f7bf18251 100644
--- a/internal/consensus/state_add_vote.go
+++ b/internal/consensus/state_add_vote.go
@@ -1,6 +1,7 @@
 package consensus
 
 import (
+	"bytes"
 	"context"
 	"errors"
 
@@ -238,6 +239,14 @@ func addVoteVerifyVoteExtensionMw(
 				return next(ctx, stateData, vote)
 			}
 
+			// If we already know of this vote, return false to not verify it multiple times
+			existing := stateData.Votes.GetVoteSet(vote.Round, vote.Type).GetByIndex(vote.ValidatorIndex)
+			if existing != nil &&
+				bytes.Equal(existing.BlockSignature, vote.BlockSignature) &&
+				bytes.Equal(existing.VoteExtensions.Fingerprint(), vote.VoteExtensions.Fingerprint()) {
+				return false, nil
+			}
+
 			// The core fields of the vote message were already validated in the
 			// consensus reactor when the vote was received.
 			// Here, we verify the signature of the vote extension included in the vote