USB: serial: io_edgeport: fix memory leaks in attach error path

commit c5c0c555 upstream.

Private data, URBs and buffers allocated for Epic devices during
attach were never released on errors (e.g. missing endpoints).

Fixes: 6e8cf775 ("USB: add EPIC support to the io_edgeport driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/usb/serial/io_edgeport.c

@@ -2856,14 +2856,16 @@ static int edge_startup(struct usb_serial *serial)
 				/* not set up yet, so do it now */
 				edge_serial->interrupt_read_urb =
 						usb_alloc_urb(0, GFP_KERNEL);
-				if (!edge_serial->interrupt_read_urb)
-					return -ENOMEM;
+				if (!edge_serial->interrupt_read_urb) {
+					response = -ENOMEM;
+					break;
+				}
 
 				edge_serial->interrupt_in_buffer =
 					kmalloc(buffer_size, GFP_KERNEL);
 				if (!edge_serial->interrupt_in_buffer) {
-					usb_free_urb(edge_serial->interrupt_read_urb);
-					return -ENOMEM;
+					response = -ENOMEM;
+					break;
 				}
 				edge_serial->interrupt_in_endpoint =
 						endpoint->bEndpointAddress;
@@ -2891,14 +2893,16 @@ static int edge_startup(struct usb_serial *serial)
 				/* not set up yet, so do it now */
 				edge_serial->read_urb =
 						usb_alloc_urb(0, GFP_KERNEL);
-				if (!edge_serial->read_urb)
-					return -ENOMEM;
+				if (!edge_serial->read_urb) {
+					response = -ENOMEM;
+					break;
+				}
 
 				edge_serial->bulk_in_buffer =
 					kmalloc(buffer_size, GFP_KERNEL);
 				if (!edge_serial->bulk_in_buffer) {
-					usb_free_urb(edge_serial->read_urb);
-					return -ENOMEM;
+					response = -ENOMEM;
+					break;
 				}
 				edge_serial->bulk_in_endpoint =
 						endpoint->bEndpointAddress;
@@ -2924,9 +2928,22 @@ static int edge_startup(struct usb_serial *serial)
 			}
 		}
 
-		if (!interrupt_in_found || !bulk_in_found || !bulk_out_found) {
-			dev_err(ddev, "Error - the proper endpoints were not found!\n");
-			return -ENODEV;
+		if (response || !interrupt_in_found || !bulk_in_found ||
+							!bulk_out_found) {
+			if (!response) {
+				dev_err(ddev, "expected endpoints not found\n");
+				response = -ENODEV;
+			}
+
+			usb_free_urb(edge_serial->interrupt_read_urb);
+			kfree(edge_serial->interrupt_in_buffer);
+
+			usb_free_urb(edge_serial->read_urb);
+			kfree(edge_serial->bulk_in_buffer);
+
+			kfree(edge_serial);
+
+			return response;
 		}
 
 		/* start interrupt read for this edgeport this interrupt will