smb: client: fix iface port assignment in parse_server_interfaces

parse_server_interfaces() initializes interface socket addresses with
CIFS_PORT. When the mount uses a non-default port this overwrites the
configured destination port.

Later, cifs_chan_update_iface() copies this sockaddr into server->dstaddr,
causing reconnect attempts to use the wrong port after server interface
updates.

Use the existing port from server->dstaddr instead.

Cc: stable@vger.kernel.org
Fixes: fe856be ("CIFS: parse and store info on iface queries")
Tested-by: Dr. Thomas Orgis <thomas.orgis@uni-hamburg.de>
Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: hac-v

fs/smb/client/smb2ops.c

@@ -628,6 +628,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 	struct smb_sockaddr_in6 *p6;
 	struct cifs_server_iface *info = NULL, *iface = NULL, *niface = NULL;
 	struct cifs_server_iface tmp_iface;
+	__be16 port;
 	ssize_t bytes_left;
 	size_t next = 0;
 	int nb_iface = 0;
@@ -662,6 +663,15 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 		goto out;
 	}
 
+	spin_lock(&ses->server->srv_lock);
+	if (ses->server->dstaddr.ss_family == AF_INET)
+		port = ((struct sockaddr_in *)&ses->server->dstaddr)->sin_port;
+	else if (ses->server->dstaddr.ss_family == AF_INET6)
+		port = ((struct sockaddr_in6 *)&ses->server->dstaddr)->sin6_port;
+	else
+		port = cpu_to_be16(CIFS_PORT);
+	spin_unlock(&ses->server->srv_lock);
+
 	while (bytes_left >= (ssize_t)sizeof(*p)) {
 		memset(&tmp_iface, 0, sizeof(tmp_iface));
 		/* default to 1Gbps when link speed is unset */
@@ -682,7 +692,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 			memcpy(&addr4->sin_addr, &p4->IPv4Address, 4);
 
 			/* [MS-SMB2] 2.2.32.5.1.1 Clients MUST ignore these */
-			addr4->sin_port = cpu_to_be16(CIFS_PORT);
+			addr4->sin_port = port;
 
 			cifs_dbg(FYI, "%s: ipv4 %pI4\n", __func__,
 				 &addr4->sin_addr);
@@ -696,7 +706,7 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
 			/* [MS-SMB2] 2.2.32.5.1.2 Clients MUST ignore these */
 			addr6->sin6_flowinfo = 0;
 			addr6->sin6_scope_id = 0;
-			addr6->sin6_port = cpu_to_be16(CIFS_PORT);
+			addr6->sin6_port = port;
 
 			cifs_dbg(FYI, "%s: ipv6 %pI6\n", __func__,
 				 &addr6->sin6_addr);