[PATCH 5.6 147/177] xfrm: espintcp: save and call old ->sk_destruct

[Greg Kroah-Hartman]

From: Sabrina Dubroca <s...@queasysnail.net>

commit 9f0cadc32d738f0f0c8e30be83be7087c7b85ee5 upstream.

When ESP encapsulation is enabled on a TCP socket, I'm replacing the
existing ->sk_destruct callback with espintcp_destruct. We still need to
call the old callback to perform the other cleanups when the socket is
destroyed. Save the old callback, and call it from espintcp_destruct.

Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)")
Signed-off-by: Sabrina Dubroca <s...@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klass...@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 include/net/espintcp.h |    1 +
 net/xfrm/espintcp.c    |    2 ++
 2 files changed, 3 insertions(+)

--- a/include/net/espintcp.h
+++ b/include/net/espintcp.h
@@ -25,6 +25,7 @@ struct espintcp_ctx {
        struct espintcp_msg partial;
        void (*saved_data_ready)(struct sock *sk);
        void (*saved_write_space)(struct sock *sk);
+       void (*saved_destruct)(struct sock *sk);
        struct work_struct work;
        bool tx_running;
 };
--- a/net/xfrm/espintcp.c
+++ b/net/xfrm/espintcp.c
@@ -379,6 +379,7 @@ static void espintcp_destruct(struct soc
 {
        struct espintcp_ctx *ctx = espintcp_getctx(sk);
 
+       ctx->saved_destruct(sk);
        kfree(ctx);
 }
 
@@ -419,6 +420,7 @@ static int espintcp_init_sk(struct sock
        sk->sk_socket->ops = &espintcp_ops;
        ctx->saved_data_ready = sk->sk_data_ready;
        ctx->saved_write_space = sk->sk_write_space;
+       ctx->saved_destruct = sk->sk_destruct;
        sk->sk_data_ready = espintcp_data_ready;
        sk->sk_write_space = espintcp_write_space;
        sk->sk_destruct = espintcp_destruct;