From d9a44960d7efacc0143b391df5aaf44d44e57d43 Mon Sep 17 00:00:00 2001
From: hklcf <hklcf@users.noreply.github.com>
Date: Sat, 23 May 2026 09:53:20 +0800
Subject: [PATCH] fix(route): prevent use-after-close race on PacketConn in
 sniffing loop

When ctx is cancelled during packet sniffing, inputPacketConn.Close()
is called while a goroutine may still be calling ReadPacket() and
SetReadDeadline() on the same conn. Wait for the goroutine to finish
after close to prevent concurrent access.

Fixes #4161
---
 route/route.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/route/route.go b/route/route.go
index d7894c6f1a..9828efd32c 100644
--- a/route/route.go
+++ b/route/route.go
@@ -726,6 +726,7 @@ func (r *Router) actionSniff(
 			case <-done:
 			case <-ctx.Done():
 				inputPacketConn.Close()
+				<-done
 				fatalErr = ctx.Err()
 				return
 			}