From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 953C5C433E7 for ; Sat, 17 Oct 2020 05:58:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61F1320720 for ; Sat, 17 Oct 2020 05:58:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436819AbgJQF6n (ORCPT ); Sat, 17 Oct 2020 01:58:43 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:15753 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2436811AbgJQF6n (ORCPT ); Sat, 17 Oct 2020 01:58:43 -0400 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 28753F2EBE1BB435542E; Sat, 17 Oct 2020 10:12:16 +0800 (CST) Received: from huawei.com (10.175.104.175) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.487.0; Sat, 17 Oct 2020 10:12:07 +0800 From: Shijie Luo To: CC: , , , , , , Subject: [PATCH V2] mm: fix potential pte_unmap_unlock pte error Date: Fri, 16 Oct 2020 22:11:51 -0400 Message-ID: <20201017021151.28104-1-luoshijie1@huawei.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.104.175] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When flags don't have MPOL_MF_MOVE or MPOL_MF_MOVE_ALL bits, code breaks and passing origin pte - 1 to pte_unmap_unlock seems like not a good idea. Signed-off-by: Shijie Luo Signed-off-by: Michal Hocko Signed-off-by: Miaohe Lin --- mm/mempolicy.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 3fde772ef5ef..3ca4898f3f24 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -525,7 +525,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, unsigned long flags = qp->flags; int ret; bool has_unmovable = false; - pte_t *pte; + pte_t *pte, *mapped_pte; spinlock_t *ptl; ptl = pmd_trans_huge_lock(pmd, vma); @@ -539,7 +539,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, if (pmd_trans_unstable(pmd)) return 0; - pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); + mapped_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl); for (; addr != end; pte++, addr += PAGE_SIZE) { if (!pte_present(*pte)) continue; @@ -571,7 +571,7 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr, } else break; } - pte_unmap_unlock(pte - 1, ptl); + pte_unmap_unlock(mapped_pte, ptl); cond_resched(); if (has_unmovable) -- 2.19.1