[PATCH 4.15 082/122] tcp: tracepoint: only call trace_tcp_send_reset with full socket

From: Greg Kroah-Hartman
Date: Wed Mar 07 2018 - 15:29:57 EST


4.15-stable review patch. If anyone has any objections, please let me know.

------------------

From: Song Liu <songliubraving@xxxxxx>


[ Upstream commit 5c487bb9adddbc1d23433e09d2548759375c2b52 ]

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@xxxxxx>
Reviewed-by: Lawrence Brakmo <brakmo@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/tcp_ipv4.c | 3 ++-
net/ipv6/tcp_ipv6.c | 3 ++-
2 files changed, 4 insertions(+), 2 deletions(-)

--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -705,7 +705,8 @@ static void tcp_v4_send_reset(const stru
*/
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) !=
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -943,7 +943,8 @@ static void tcp_v6_send_reset(const stru

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);