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

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@gmail.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index bfcf153bc82907f31ccc1921256622a82bf20d2f..2b57cd96dd58da446266ae6fb50f295d1941401a 100644 (file)
--- 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;