1 files changed, 21 insertions, 8 deletions

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 7072556b38f6..1a565095376a 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -124,12 +124,21 @@ static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk,
 					  struct request_sock *req,
 					  struct dst_entry *dst,
 					  struct request_sock *req_unhash,
-					  bool *own_req)
+					  bool *own_req,
+					  void (*opt_child_init)(struct sock *newsk,
+								 const struct sock *sk))
 {
 	struct smc_sock *smc;
 	struct sock *child;
 
-	smc = smc_clcsock_user_data(sk);
+	rcu_read_lock();
+	smc = smc_clcsock_user_data_rcu(sk);
+	if (!smc || !refcount_inc_not_zero(&smc->sk.sk_refcnt)) {
+		rcu_read_unlock();
+		smc = NULL;
+		goto drop;
+	}
+	rcu_read_unlock();
 
 	if (READ_ONCE(sk->sk_ack_backlog) + atomic_read(&smc->queued_smc_hs) >
 				sk->sk_max_ack_backlog)
@@ -142,7 +151,7 @@ static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk,
 
 	/* passthrough to original syn recv sock fct */
 	child = smc->ori_af_ops->syn_recv_sock(sk, skb, req, dst, req_unhash,
-					       own_req);
+					       own_req, opt_child_init);
 	/* child must not inherit smc or its ops */
 	if (child) {
 		rcu_assign_sk_user_data(child, NULL);
@@ -151,11 +160,14 @@ static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk,
 		if (inet_csk(child)->icsk_af_ops == inet_csk(sk)->icsk_af_ops)
 			inet_csk(child)->icsk_af_ops = smc->ori_af_ops;
 	}
+	sock_put(&smc->sk);
 	return child;
 
 drop:
 	dst_release(dst);
 	tcp_listendrop(sk);
+	if (smc)
+		sock_put(&smc->sk);
 	return NULL;
 }
 
@@ -252,7 +264,7 @@ static void smc_fback_restore_callbacks(struct smc_sock *smc)
 	struct sock *clcsk = smc->clcsock->sk;
 
 	write_lock_bh(&clcsk->sk_callback_lock);
-	clcsk->sk_user_data = NULL;
+	rcu_assign_sk_user_data(clcsk, NULL);
 
 	smc_clcsock_restore_cb(&clcsk->sk_state_change, &smc->clcsk_state_change);
 	smc_clcsock_restore_cb(&clcsk->sk_data_ready, &smc->clcsk_data_ready);
@@ -900,7 +912,7 @@ static void smc_fback_replace_callbacks(struct smc_sock *smc)
 	struct sock *clcsk = smc->clcsock->sk;
 
 	write_lock_bh(&clcsk->sk_callback_lock);
-	clcsk->sk_user_data = (void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
+	__rcu_assign_sk_user_data_with_flags(clcsk, smc, SK_USER_DATA_NOCOPY);
 
 	smc_clcsock_replace_cb(&clcsk->sk_state_change, smc_fback_state_change,
 			       &smc->clcsk_state_change);
@@ -2663,8 +2675,8 @@ int smc_listen(struct socket *sock, int backlog)
 	 * smc-specific sk_data_ready function
 	 */
 	write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
-	smc->clcsock->sk->sk_user_data =
-		(void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
+	__rcu_assign_sk_user_data_with_flags(smc->clcsock->sk, smc,
+					     SK_USER_DATA_NOCOPY);
 	smc_clcsock_replace_cb(&smc->clcsock->sk->sk_data_ready,
 			       smc_clcsock_data_ready, &smc->clcsk_data_ready);
 	write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
@@ -2685,10 +2697,11 @@ int smc_listen(struct socket *sock, int backlog)
 		write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
 		smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
 				       &smc->clcsk_data_ready);
-		smc->clcsock->sk->sk_user_data = NULL;
+		rcu_assign_sk_user_data(smc->clcsock->sk, NULL);
 		write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
 		goto out;
 	}
+	sock_set_flag(sk, SOCK_RCU_FREE);
 	sk->sk_max_ack_backlog = backlog;
 	sk->sk_ack_backlog = 0;
 	sk->sk_state = SMC_LISTEN;