===== mm/mremap.c 1.33 vs edited =====
--- 1.33/mm/mremap.c	Sat Aug 23 23:50:10 2003
+++ edited/mm/mremap.c	Mon Jan  5 08:34:21 2004
@@ -315,6 +315,10 @@
 	old_len = PAGE_ALIGN(old_len);
 	new_len = PAGE_ALIGN(new_len);
 
+	/* Don't allow the degenerate cases */
+	if (!(old_len | new_len))
+		goto out;
+
 	/* new_addr is only valid if MREMAP_FIXED is specified */
 	if (flags & MREMAP_FIXED) {
 		if (new_addr & ~PAGE_MASK)