mm: check the return value of lookup_page_ext for all call sites

[cascardo/linux.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index f8f3bfc..d27e8b9 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -656,6 +656,9 @@ static inline void set_page_guard(struct zone *zone, struct page *page,
                return;
 
        page_ext = lookup_page_ext(page);
+       if (unlikely(!page_ext))
+               return;
+
        __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
 
        INIT_LIST_HEAD(&page->lru);
@@ -673,6 +676,9 @@ static inline void clear_page_guard(struct zone *zone, struct page *page,
                return;
 
        page_ext = lookup_page_ext(page);
+       if (unlikely(!page_ext))
+               return;
+
        __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
 
        set_page_private(page, 0);