diff --git a/fs/overlay_util.c b/fs/overlay_util.c
index 0daff19..063f8c5 100644
--- a/fs/overlay_util.c
+++ b/fs/overlay_util.c
@@ -10,6 +10,7 @@
 #include <linux/overlay_util.h>
 #include <linux/fs.h>
 #include <linux/file.h>
+#include <linux/mm.h>
 #include "internal.h"
 
 static bool overlay_file_consistent(struct file *file)
@@ -36,4 +37,22 @@ ssize_t overlay_read_iter(struct file *file, struct kiocb *kio,
 }
 EXPORT_SYMBOL(overlay_read_iter);
 
+int overlay_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	if (unlikely(!overlay_file_consistent(file))) {
+		file = filp_clone_open(file);
+		if (IS_ERR(file))
+			return PTR_ERR(file);
+
+		fput(vma->vm_file);
+		/* transfer ref: */
+		vma->vm_file = file;
+
+		if (!file->f_op->mmap)
+			return -ENODEV;
+	}
+	return file->f_op->mmap(file, vma);
+}
+EXPORT_SYMBOL(overlay_mmap);
+
 #endif /* IS_ENABLED(CONFIG_OVERLAY_FS) */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4728c51..6e74b72 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1739,6 +1739,9 @@ static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio,
 
 static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
 {
+	if (unlikely(is_overlay_file(file)))
+		return overlay_mmap(file, vma);
+
 	return file->f_op->mmap(file, vma);
 }
 
diff --git a/include/linux/overlay_util.h b/include/linux/overlay_util.h
index 886be90..2cd66bc 100644
--- a/include/linux/overlay_util.h
+++ b/include/linux/overlay_util.h
@@ -6,8 +6,10 @@
 struct file;
 struct kiocb;
 struct iov_iter;
+struct vm_area_struct;
 
 extern ssize_t overlay_read_iter(struct file *file, struct kiocb *kio,
 				 struct iov_iter *iter);
+extern int overlay_mmap(struct file *file, struct vm_area_struct *vma);
 
 #endif /* _LINUX_OVERLAY_FS_H */
diff --git a/mm/mmap.c b/mm/mmap.c
index 3714aa4..c43dfe1 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1746,6 +1746,9 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 	return error;
 }
 
+/*
+ * Overlay needs special handling after copy-up
+ */
 unsigned long unmapped_area(struct vm_unmapped_area_info *info)
 {
 	/*