{commands,start}: remove element from list first

First remove the client from the list then close the fd. Otherwise we open
ourselves to a race where another codepath might be writing to a bad file
descriptor.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

src/lxc/commands.c

@@ -1021,8 +1021,8 @@ static void lxc_cmd_fd_cleanup(int fd, struct lxc_handler *handler,
 			continue;
 
 		/* kick client from list */
-		close(client->clientfd);
 		lxc_list_del(cur);
+		close(client->clientfd);
 		free(cur->elem);
 		free(cur);
 		/* No need to walk the whole list. If we found the state client

src/lxc/start.c

@@ -418,8 +418,8 @@ int lxc_serve_state_clients(const char *name, struct lxc_handler *handler,
 		}
 
 		/* kick client from list */
-		close(client->clientfd);
 		lxc_list_del(cur);
+		close(client->clientfd);
 		free(cur->elem);
 		free(cur);
 	}