From 3c3f35c8c5002476f0f70590af96df127cd058b2 Mon Sep 17 00:00:00 2001
From: Daniel Liu <139250065@qq.com>
Date: Thu, 21 May 2026 15:30:40 +0800
Subject: [PATCH] fix(eth/bft): avoid broadcast send blocking during shutdown

Guard BFT broadcast enqueue with the quit channel so Vote/Timeout/SyncInfo exit cleanly once shutdown starts.

Add a regression test to ensure Vote returns after BFT loop stop and does not hang.
---
 eth/bft/bft_handler.go      | 21 ++++++++++++++++++---
 eth/bft/bft_handler_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/eth/bft/bft_handler.go b/eth/bft/bft_handler.go
index 72d4e2283f5c..6122ff9ddecd 100644
--- a/eth/bft/bft_handler.go
+++ b/eth/bft/bft_handler.go
@@ -94,7 +94,9 @@ func (b *Bfter) Vote(peer string, vote *types.Vote) error {
 	}
 
 	if verified {
-		b.broadcastCh <- vote
+		if !b.enqueueForBroadcast(vote) {
+			return nil
+		}
 		err = b.consensus.voteHandler(b.blockChainReader, vote)
 		if err != nil {
 			if _, ok := err.(*utils.ErrIncomingMessageRoundTooFarFromCurrentRound); ok {
@@ -129,7 +131,9 @@ func (b *Bfter) Timeout(peer string, timeout *types.Timeout) error {
 	log.Debug("[Timeout] Received Timeout", "gap", gapNum, "hash", timeout.Hash().Hex(), "round", timeout.Round, "signer", timeout.GetSigner().Hex()) //get signer after verifyTimeout
 
 	if verified {
-		b.broadcastCh <- timeout
+		if !b.enqueueForBroadcast(timeout) {
+			return nil
+		}
 		err = b.consensus.timeoutHandler(b.blockChainReader, timeout)
 		if err != nil {
 			if _, ok := err.(*utils.ErrIncomingMessageRoundNotEqualCurrentRound); ok {
@@ -170,7 +174,9 @@ func (b *Bfter) SyncInfo(peer string, syncInfo *types.SyncInfo) error {
 
 	// Process only if verified and qualified
 	if verified {
-		b.broadcastCh <- syncInfo
+		if !b.enqueueForBroadcast(syncInfo) {
+			return nil
+		}
 		err = b.consensus.syncInfoHandler(b.blockChainReader, syncInfo)
 		if err != nil {
 			log.Error("[SyncInfo] Handle BFT SyncInfo", "error", err)
@@ -180,6 +186,15 @@ func (b *Bfter) SyncInfo(peer string, syncInfo *types.SyncInfo) error {
 	return nil
 }
 
+func (b *Bfter) enqueueForBroadcast(msg interface{}) bool {
+	select {
+	case <-b.quit:
+		return false
+	case b.broadcastCh <- msg:
+		return true
+	}
+}
+
 // Start Bft receiver
 func (b *Bfter) Start() {
 	go b.loop()
diff --git a/eth/bft/bft_handler_test.go b/eth/bft/bft_handler_test.go
index b338e64a6664..23f3cc26851b 100644
--- a/eth/bft/bft_handler_test.go
+++ b/eth/bft/bft_handler_test.go
@@ -393,3 +393,28 @@ func TestTooFarSyncInfo(t *testing.T) {
 		t.Fatalf("count mismatch: have %v on verify, have %v on handler, %v on broadcast, want %v", verifyCounter, handlerCounter, broadcastCounter, targetSyncInfo)
 	}
 }
+
+func TestVoteReturnsAfterBftStop(t *testing.T) {
+	tester := newTester()
+	tester.bfter.consensus.verifyVote = func(chain consensus.ChainReader, vote *types.Vote) (bool, error) {
+		return true, nil
+	}
+	tester.bfter.consensus.voteHandler = func(chain consensus.ChainReader, vote *types.Vote) error {
+		return nil
+	}
+
+	tester.bfter.Stop()
+
+	vote := types.Vote{ProposedBlockInfo: &types.BlockInfo{Number: big.NewInt(1350)}}
+	done := make(chan struct{})
+	go func() {
+		_ = tester.bfter.Vote(peerID, &vote)
+		close(done)
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(300 * time.Millisecond):
+		t.Fatal("Vote blocks after bft loop is stopped")
+	}
+}