diff --git a/mm/ksm.c b/mm/ksm.c
index 707be52..c842c29 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -569,14 +569,16 @@ out:
 static int is_present_pte(struct mm_struct *mm, unsigned long addr)
 {
 	pte_t *ptep;
+	int r;
 
 	ptep = get_pte(mm, addr);
 	if (!ptep)
 		return 0;
 
-	if (pte_present(*ptep))
-		return 1;
-	return 0;
+	r = pte_present(*ptep);
+	pte_unmap(ptep);
+
+	return r;
 }
 
 #define PAGEHASH_LEN 128
@@ -669,6 +671,7 @@ static int try_to_merge_one_page(struct mm_struct *mm,
 	if (!orig_ptep)
 		goto out_unlock;
 	orig_pte = *orig_ptep;
+	pte_unmap(orig_ptep);
 	if (!pte_present(orig_pte))
 		goto out_unlock;
 	if (page_to_pfn(oldpage) != pte_pfn(orig_pte))