diff --git a/kernel/pid.c b/kernel/pid.c
index e02b00996..15bbb9ddb 100755
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -560,6 +560,12 @@ int pidfd_create(struct pid *pid, unsigned int flags)
 {
 	int fd;
 
+	if (!pid || !pid_has_task(pid, PIDTYPE_TGID))
+		return -EINVAL;
+
+	if (flags & ~(O_NONBLOCK | O_RDWR | O_CLOEXEC))
+		return -EINVAL;
+
 	fd = anon_inode_getfd("[pidfd]", &pidfd_fops, get_pid(pid),
 			      flags | O_RDWR | O_CLOEXEC);
 	if (fd < 0)
@@ -599,10 +605,7 @@ SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)
 	if (!p)
 		return -ESRCH;
 
-	if (pid_has_task(p, PIDTYPE_TGID))
-		fd = pidfd_create(p, flags);
-	else
-		fd = -EINVAL;
+	fd = pidfd_create(p, flags);
 
 	put_pid(p);
 	return fd;