diff --git a/config.c b/config.c
index 19b570e..8886366 100644
--- a/config.c
+++ b/config.c
@@ -729,6 +729,7 @@ int cwmp_init(int argc, char** argv,struct cwmp *cwmp)
     }
     /* Only One instance should run*/
     cwmp->pid_file = open("/var/run/cwmpd.pid", O_CREAT | O_RDWR, 0666);
+    fcntl(cwmp->pid_file, F_SETFD, fcntl(cwmp->pid_file, F_GETFD) | FD_CLOEXEC);
     int rc = flock(cwmp->pid_file, LOCK_EX | LOCK_NB);
     if(rc) {
         if(EWOULDBLOCK != errno)
diff --git a/ubus.c b/ubus.c
index c5170a4..c201736 100644
--- a/ubus.c
+++ b/ubus.c
@@ -128,6 +128,7 @@ cwmp_handle_command(struct ubus_context *ctx, struct ubus_object *obj,
 		int error;
 		CWMP_LOG(INFO, "triggered ubus exit");
 		int rc = flock(cwmp_main.pid_file, LOCK_UN | LOCK_NB);
+		close(cwmp_main.pid_file);
 		if(rc) {
 			char *piderr = "PID file unlock failed!";
 			fprintf(stderr, "%s\n", piderr);