[PATCH 4.18 005/235] tipc: orphan sock in tipc_release()

[Greg Kroah-Hartman]

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

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

From: Cong Wang <xiyou.wangcong@xxxxxxxxx>

[ Upstream commit 0a3b8b2b215f9e84b82ae97df71292ccfd92b1e7 ]

Before we unlock the sock in tipc_release(), we have to
detach sk->sk_socket from sk, otherwise a parallel
tipc_sk_fill_sock_diag() could stil read it after we
free this socket.

Fixes: c30b70deb5f4 ("tipc: implement socket diagnostics for AF_TIPC")
Reported-and-tested-by: syzbot+48804b87c16588ad491d@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: Jon Maloy <jon.maloy@xxxxxxxxxxxx>
Cc: Ying Xue <ying.xue@xxxxxxxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Acked-by: Ying Xue <ying.xue@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/tipc/socket.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -578,6 +578,7 @@ static int tipc_release(struct socket *s
 	sk_stop_timer(sk, &sk->sk_timer);
 	tipc_sk_remove(tsk);
 
+	sock_orphan(sk);
 	/* Reject any messages that accumulated in backlog queue */
 	release_sock(sk);
 	tipc_dest_list_purge(&tsk->cong_links);