diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e50da18912dd..875064ddb9ee 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -503,7 +503,7 @@ static void tcp_grow_window(struct sock *sk, const struct sk_buff *skb)
  */
 static void tcp_init_buffer_space(struct sock *sk)
 {
-	int tcp_app_win = sock_net(sk)->ipv4.sysctl_tcp_app_win;
+	int tcp_app_win = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_app_win);
 	struct tcp_sock *tp = tcp_sk(sk);
 	int maxwin;