Index: head/sys/compat/linux/linux_file.h
===================================================================
--- head/sys/compat/linux/linux_file.h
+++ head/sys/compat/linux/linux_file.h
@@ -127,4 +127,11 @@
 #define	LINUX_F_UNLCK		2
 #endif
 
+/*
+ * renameat2 flags
+ */
+#define	LINUX_RENAME_NOREPLACE	0x00000001
+#define	LINUX_RENAME_EXCHANGE	0x00000002
+#define	LINUX_RENAME_WHITEOUT	0x00000004
+
 #endif	/* !_LINUX_FILE_H_ */
Index: head/sys/compat/linux/linux_file.c
===================================================================
--- head/sys/compat/linux/linux_file.c
+++ head/sys/compat/linux/linux_file.c
@@ -704,6 +704,13 @@
 	int error, olddfd, newdfd;
 
 	if (args->flags != 0) {
+		if (args->flags & ~(LINUX_RENAME_EXCHANGE |
+		    LINUX_RENAME_NOREPLACE | LINUX_RENAME_WHITEOUT))
+			return (EINVAL);
+		if (args->flags & LINUX_RENAME_EXCHANGE &&
+		    args->flags & (LINUX_RENAME_NOREPLACE |
+		    LINUX_RENAME_WHITEOUT))
+			return (EINVAL);
 		linux_msg(td, "renameat2 unsupported flags 0x%x",
 		    args->flags);
 		return (EINVAL);