3 files changed, 18 insertions, 26 deletions

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index a3f1c1461874..07fcc86e1fc9 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2769,30 +2769,16 @@ static void __mptcp_wr_shutdown(struct sock *sk)
 
 static void __mptcp_destroy_sock(struct sock *sk)
 {
-	struct mptcp_subflow_context *subflow, *tmp;
 	struct mptcp_sock *msk = mptcp_sk(sk);
-	LIST_HEAD(conn_list);
 
 	pr_debug("msk=%p", msk);
 
 	might_sleep();
 
-	/* join list will be eventually flushed (with rst) at sock lock release time*/
-	list_splice_init(&msk->conn_list, &conn_list);
-
 	mptcp_stop_timer(sk);
 	sk_stop_timer(sk, &sk->sk_timer);
 	msk->pm.status = 0;
 
-	/* clears msk->subflow, allowing the following loop to close
-	 * even the initial subflow
-	 */
-	mptcp_dispose_initial_subflow(msk);
-	list_for_each_entry_safe(subflow, tmp, &conn_list, node) {
-		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
-		__mptcp_close_ssk(sk, ssk, subflow, 0);
-	}
-
 	sk->sk_prot->destroy(sk);
 
 	WARN_ON_ONCE(msk->rmem_fwd_alloc);
@@ -2884,24 +2870,20 @@ static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)
 
 static int mptcp_disconnect(struct sock *sk, int flags)
 {
-	struct mptcp_subflow_context *subflow, *tmp;
 	struct mptcp_sock *msk = mptcp_sk(sk);
 
 	inet_sk_state_store(sk, TCP_CLOSE);
 
-	list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
-		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
-
-		__mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_FASTCLOSE);
-	}
-
 	mptcp_stop_timer(sk);
 	sk_stop_timer(sk, &sk->sk_timer);
 
 	if (mptcp_sk(sk)->token)
 		mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL);
 
-	mptcp_destroy_common(msk);
+	/* msk->subflow is still intact, the following will not free the first
+	 * subflow
+	 */
+	mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE);
 	msk->last_snd = NULL;
 	WRITE_ONCE(msk->flags, 0);
 	msk->cb_flags = 0;
@@ -3051,12 +3033,17 @@ out:
 	return newsk;
 }
 
-void mptcp_destroy_common(struct mptcp_sock *msk)
+void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags)
 {
+	struct mptcp_subflow_context *subflow, *tmp;
 	struct sock *sk = (struct sock *)msk;
 
 	__mptcp_clear_xmit(sk);
 
+	/* join list will be eventually flushed (with rst) at sock lock release time */
+	list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node)
+		__mptcp_close_ssk(sk, mptcp_subflow_tcp_sock(subflow), subflow, flags);
+
 	/* move to sk_receive_queue, sk_stream_kill_queues will purge it */
 	mptcp_data_lock(sk);
 	skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue);
@@ -3078,7 +3065,11 @@ static void mptcp_destroy(struct sock *sk)
 {
 	struct mptcp_sock *msk = mptcp_sk(sk);
 
-	mptcp_destroy_common(msk);
+	/* clears msk->subflow, allowing the following to close
+	 * even the initial subflow
+	 */
+	mptcp_dispose_initial_subflow(msk);
+	mptcp_destroy_common(msk, 0);
 	sk_sockets_allocated_dec(sk);
 }
 
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 5d6043c16b09..40881a7df5d5 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -717,7 +717,7 @@ static inline void mptcp_write_space(struct sock *sk)
 	}
 }
 
-void mptcp_destroy_common(struct mptcp_sock *msk);
+void mptcp_destroy_common(struct mptcp_sock *msk, unsigned int flags);
 
 #define MPTCP_TOKEN_MAX_RETRIES	4
 
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 901c763dcdbb..c7d49fb6e7bd 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -621,7 +621,8 @@ static void mptcp_sock_destruct(struct sock *sk)
 		sock_orphan(sk);
 	}
 
-	mptcp_destroy_common(mptcp_sk(sk));
+	/* We don't need to clear msk->subflow, as it's still NULL at this point */
+	mptcp_destroy_common(mptcp_sk(sk), 0);
 	inet_sock_destruct(sk);
 }