mm/sparse.c: check the return value of sparse_index_alloc()

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/mm/sparse.c b/mm/sparse.c
index e06f514fe04f..d245e59048a8 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -83,6 +83,8 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid)
                 return -EEXIST;
 
         section = sparse_index_alloc(nid);
+        if (!section)
+                return -ENOMEM;
         /*
          * This lock keeps two different sections from
          * reallocating for the same index