1 files changed, 13 insertions, 2 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index ee97d38ed7d9..4bad3267537a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -734,9 +734,20 @@ void page_move_anon_rmap(struct page *page,
 static void __page_set_anon_rmap(struct page *page,
         struct vm_area_struct *vma, unsigned long address)
 {
-        struct anon_vma *anon_vma = vma->anon_vma;
+        struct anon_vma_chain *avc;
+        struct anon_vma *anon_vma;
+
+        BUG_ON(!vma->anon_vma);
+
+        /*
+         * We must use the _oldest_ possible anon_vma for the page mapping!
+         *
+         * So take the last AVC chain entry in the vma, which is the deepest
+         * ancestor, and use the anon_vma from that.
+         */
+        avc = list_entry(vma->anon_vma_chain.prev, struct anon_vma_chain, same_vma);
+        anon_vma = avc->anon_vma;
 
-        BUG_ON(!anon_vma);
         anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
         page->mapping = (struct address_space *) anon_vma;
         page->index = linear_page_index(vma, address);