diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index cfa0dba..3a494cf 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -914,6 +914,18 @@ static struct page *khugepaged_alloc_hugepage(bool *wait)
 
 static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
 {
+	/*
+	 * If the hpage allocated earlier was briefly exposed in page cache
+	 * before collapse_file() failed, it is possible that racing lookups
+	 * have not yet completed, and would then be unpleasantly surprised by
+	 * finding the hpage reused for the same mapping at a different offset.
+	 * Just release the previous allocation if there is any danger of that.
+	 */
+	if (*hpage && page_count(*hpage) > 1) {
+		put_page(*hpage);
+		*hpage = NULL;
+	}
+
 	if (!*hpage)
 		*hpage = khugepaged_alloc_hugepage(wait);