From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753023Ab3LPJei (ORCPT ); Mon, 16 Dec 2013 04:34:38 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:9688 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751971Ab3LPJeg (ORCPT ); Mon, 16 Dec 2013 04:34:36 -0500 Message-ID: <52AEC8FD.6050200@huawei.com> Date: Mon, 16 Dec 2013 17:33:49 +0800 From: Jianguo Wu User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Andrew Morton CC: , Naoya Horiguchi , Mel Gorman , , , qiuxishi , Hanjun Guo Subject: [PATCH] mm/hugetlb: check for pte NULL pointer in __page_check_address() Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.135.74.216] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In __page_check_address(), if address's pud is not present, huge_pte_offset() will return NULL, we should check the return value. Signed-off-by: Jianguo Wu --- mm/rmap.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index 55c8b8d..068522d 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -600,7 +600,11 @@ pte_t *__page_check_address(struct page *page, struct mm_struct *mm, spinlock_t *ptl; if (unlikely(PageHuge(page))) { + /* when pud is not present, pte will be NULL */ pte = huge_pte_offset(mm, address); + if (!pte) + return NULL; + ptl = huge_pte_lockptr(page_hstate(page), mm, pte); goto check; } -- 1.7.1