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

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>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dae27ba3be2c8523cd032ad330e2f5a32fbffaf3..bb28a5f9db8ddbf2f65391fe9206ca99b46a256b 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2422,6 +2422,8 @@ 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;