[PATCH] hugetlb: release pages in the error path of hugetlb_cow()

[Hillf Danton]

commit ea4039a34c4c206d015d34a49d0b00868e37db1d upstream.

If we fail to prepare an anon_vma, the {new, old}_page should be released,
or they will leak.

Signed-off-by: Hillf Danton <dhillf at gmail.com>
Reviewed-by: Andrea Arcangeli <aarcange at redhat.com>
Cc: Hugh Dickins <hughd at google.com>
Cc: Johannes Weiner <jweiner at redhat.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
---
 mm/hugetlb.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index bfcf153..2b57cd9 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2415,6 +2415,8 @@ retry_avoidcopy:
         * anon_vma prepared.
         */
        if (unlikely(anon_vma_prepare(vma))) {
+               page_cache_release(new_page);
+               page_cache_release(old_page);
                /* Caller expects lock to be held */
                spin_lock(&mm->page_table_lock);
                return VM_FAULT_OOM;
-- 
1.7.7.3


-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic