From 18c666a1abb7a9225697f7e9dc0ddb91eb3f214e Mon Sep 17 00:00:00 2001
From: Terry Chan <hi@terrychan.me>
Date: Tue, 13 Jun 2023 23:44:48 +0800
Subject: [PATCH] Fix: aysnc exchange with new context (#2788)

---
 dns/resolver.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/dns/resolver.go b/dns/resolver.go
index 50e0c3d..75c907c 100644
--- a/dns/resolver.go
+++ b/dns/resolver.go
@@ -141,7 +141,11 @@ func (r *Resolver) ExchangeContext(ctx context.Context, m *D.Msg) (msg *D.Msg, e
 		msg = cache.(*D.Msg).Copy()
 		if expireTime.Before(now) {
 			setMsgTTL(msg, uint32(1)) // Continue fetch
-			go r.exchangeWithoutCache(ctx, m)
+			go func() {
+				ctx, cancel := context.WithTimeout(context.Background(), resolver.DefaultDNSTimeout)
+				r.exchangeWithoutCache(ctx, m)
+				cancel()
+			}()
 		} else {
 			// updating TTL by subtracting common delta time from each DNS record
 			updateMsgTTL(msg, uint32(time.Until(expireTime).Seconds()))