From 37052fd5bc050f8eaf80b986d511f3c278233cca Mon Sep 17 00:00:00 2001
From: Viktor Liu <17948409+lixmal@users.noreply.github.com>
Date: Thu, 21 May 2026 01:46:51 +0900
Subject: [PATCH] [client] Fix nil channel panic in external chain monitor stop
 (#6224)

---
 client/firewall/nftables/external_chain_monitor_linux.go | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/client/firewall/nftables/external_chain_monitor_linux.go b/client/firewall/nftables/external_chain_monitor_linux.go
index 2a2e04c09..9c91c95cf 100644
--- a/client/firewall/nftables/external_chain_monitor_linux.go
+++ b/client/firewall/nftables/external_chain_monitor_linux.go
@@ -52,9 +52,10 @@ func (m *externalChainMonitor) start() {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	m.cancel = cancel
-	m.done = make(chan struct{})
+	done := make(chan struct{})
+	m.done = done
 
-	go m.run(ctx)
+	go m.run(ctx, done)
 }
 
 func (m *externalChainMonitor) stop() {
@@ -72,8 +73,8 @@ func (m *externalChainMonitor) stop() {
 	<-done
 }
 
-func (m *externalChainMonitor) run(ctx context.Context) {
-	defer close(m.done)
+func (m *externalChainMonitor) run(ctx context.Context, done chan struct{}) {
+	defer close(done)
 
 	bo := &backoff.ExponentialBackOff{
 		InitialInterval:     externalMonitorInitInterval,