From: WANG Cong <xiyou.wangcong@gmail.com>

Since sparse_index_alloc() can return NULL on memory allocation failure,
we must deal with the failure condition when calling it.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/sparse.c |    2 ++
 1 file changed, 2 insertions(+)

diff -puN mm/sparse.c~mm-sparsec-check-the-return-value-of-sparse_index_alloc mm/sparse.c
--- a/mm/sparse.c~mm-sparsec-check-the-return-value-of-sparse_index_alloc
+++ a/mm/sparse.c
@@ -83,6 +83,8 @@ static int __meminit sparse_index_init(u
 		return -EEXIST;
 
 	section = sparse_index_alloc(nid);
+	if (!section)
+		return -ENOMEM;
 	/*
 	 * This lock keeps two different sections from
 	 * reallocating for the same index
_