From e297fb4e603dbc776564b907614ed40710f795c6 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.cz>
Date: Fri, 20 Jan 2012 14:33:55 -0800
Subject: [PATCH] --- yaml --- r: 286594 b: refs/heads/master c:
 687875fb7de4a95223af20ee024282fa9099f860 h: refs/heads/master v: v3

---
 [refs]                |  2 +-
 trunk/mm/page_alloc.c | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 528f99de2381..122ec76e7b97 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6536e3123e5d3371a6f52e32a3d0694bcc987702
+refs/heads/master: 687875fb7de4a95223af20ee024282fa9099f860
diff --git a/trunk/mm/page_alloc.c b/trunk/mm/page_alloc.c
index 0027d8f4a1bb..21c272d517bc 100644
--- a/trunk/mm/page_alloc.c
+++ b/trunk/mm/page_alloc.c
@@ -5414,6 +5414,17 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
 bool is_pageblock_removable_nolock(struct page *page)
 {
 	struct zone *zone = page_zone(page);
+	unsigned long pfn = page_to_pfn(page);
+
+	/*
+	 * We have to be careful here because we are iterating over memory
+	 * sections which are not zone aware so we might end up outside of
+	 * the zone but still within the section.
+	 */
+	if (!zone || zone->zone_start_pfn > pfn ||
+			zone->zone_start_pfn + zone->spanned_pages <= pfn)
+		return false;
+
 	return __count_immobile_pages(zone, page, 0);
 }