From: Song Liu <songliubraving@fb.com>
Date: Wed, 7 Feb 2018 04:50:23 +0000 (-0800)
Subject: tcp: tracepoint: only call trace_tcp_send_reset with full socket
X-Git-Tag: v4.19~1593^2~25
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5c487bb9adddbc1d23433e09d2548759375c2b52;p=platform%2Fkernel%2Flinux-rpi.git

tcp: tracepoint: only call trace_tcp_send_reset with full socket

tracepoint tcp_send_reset requires a full socket to work. However, it
may be called when in TCP_TIME_WAIT:

        case TCP_TW_RST:
                tcp_v6_send_reset(sk, skb);
                inet_twsk_deschedule_put(inet_twsk(sk));
                goto discard_it;

To avoid this problem, this patch checks the socket with sk_fullsock()
before calling trace_tcp_send_reset().

Fixes: c24b14c46bb8 ("tcp: add tracepoint trace_tcp_send_reset")
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 95738aa..f8ad397 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -705,7 +705,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
 	 */
 	if (sk) {
 		arg.bound_dev_if = sk->sk_bound_dev_if;
-		trace_tcp_send_reset(sk, skb);
+		if (sk_fullsock(sk))
+			trace_tcp_send_reset(sk, skb);
 	}
 
 	BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) !=
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index a1ab29e..412139f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -942,7 +942,8 @@ static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
 
 	if (sk) {
 		oif = sk->sk_bound_dev_if;
-		trace_tcp_send_reset(sk, skb);
+		if (sk_fullsock(sk))
+			trace_tcp_send_reset(sk, skb);
 	}
 
 	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, 0);