Commit e6bb9193 authored by Namjae Jeon's avatar Namjae Jeon Committed by Steve French
Browse files

ksmbd: limit repeated connections from clients with the same IP 



Repeated connections from clients with the same IP address may exhaust
the max connections and prevent other normal client connections.
This patch limit repeated connections from clients with the same IP.

Reported-by: default avatartianshuo han <hantianshuo233@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent a6c015b7

fs/smb/server/connection.h

+1 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ struct ksmbd_conn { 
	struct mutex			srv_mutex;

	int				status;

	unsigned int			cli_cap;

	__be32				inet_addr;

	char				*request_buf;

	struct ksmbd_transport		*transport;

	struct nls_table		*local_nls;

fs/smb/server/transport_tcp.c

+17 −0
Original line number Diff line number Diff line
@@ -87,6 +87,7 @@ static struct tcp_transport *alloc_transport(struct socket *client_sk) 
		return NULL;

	}



	conn->inet_addr = inet_sk(client_sk->sk)->inet_daddr;

	conn->transport = KSMBD_TRANS(t);

	KSMBD_TRANS(t)->conn = conn;

	KSMBD_TRANS(t)->ops = &ksmbd_tcp_transport_ops;
@@ -230,6 +231,8 @@ static int ksmbd_kthread_fn(void *p) 
{

	struct socket *client_sk = NULL;

	struct interface *iface = (struct interface *)p;

	struct inet_sock *csk_inet;

	struct ksmbd_conn *conn;

	int ret;



	while (!kthread_should_stop()) {
@@ -248,6 +251,20 @@ static int ksmbd_kthread_fn(void *p) 
			continue;

		}



		/*

		 * Limits repeated connections from clients with the same IP.

		 */

		csk_inet = inet_sk(client_sk->sk);

		down_read(&conn_list_lock);

		list_for_each_entry(conn, &conn_list, conns_list)

			if (csk_inet->inet_daddr == conn->inet_addr) {

				ret = -EAGAIN;

				break;

			}

		up_read(&conn_list_lock);

		if (ret == -EAGAIN)

			continue;



		if (server_conf.max_connections &&

		    atomic_inc_return(&active_num_conn) >= server_conf.max_connections) {

			pr_info_ratelimited("Limit the maximum number of connections(%u)\n",