diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2ee0fd3..0ab02fb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -360,9 +360,11 @@
 	__SetPageHead(page);
 	for (i = 1; i < nr_pages; i++) {
 		struct page *p = page + i;
-		__SetPageTail(p);
 		set_page_count(p, 0);
 		p->first_page = page;
+		/* Make sure p->first_page is always valid for PageTail() */
+		smp_wmb();
+		__SetPageTail(p);
 	}
 }