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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 BA8D2C4320E for ; Sat, 14 Aug 2021 10:51:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A4DE160F39 for ; Sat, 14 Aug 2021 10:51:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238079AbhHNKwM (ORCPT ); Sat, 14 Aug 2021 06:52:12 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:8019 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237914AbhHNKwD (ORCPT ); Sat, 14 Aug 2021 06:52:03 -0400 Received: from dggeme703-chm.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Gmy022YL3zYnkc; Sat, 14 Aug 2021 18:51:14 +0800 (CST) Received: from huawei.com (10.175.124.27) by dggeme703-chm.china.huawei.com (10.1.199.99) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Sat, 14 Aug 2021 18:51:32 +0800 From: Miaohe Lin To: , CC: , , , Subject: [PATCH 2/4] mm/hwpoison: fix potential pte_unmap_unlock pte error Date: Sat, 14 Aug 2021 18:51:29 +0800 Message-ID: <20210814105131.48814-3-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20210814105131.48814-1-linmiaohe@huawei.com> References: <20210814105131.48814-1-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggeme703-chm.china.huawei.com (10.1.199.99) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If the first pte is equal to poisoned_pfn, i.e. check_hwpoisoned_entry() return 1, the wrong ptep - 1 would be passed to pte_unmap_unlock(). Fixes: ad9c59c24095 ("mm,hwpoison: send SIGBUS with error virutal address") Signed-off-by: Miaohe Lin --- mm/memory-failure.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 052ec9ee7cf6..54f61133bf60 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -632,7 +632,7 @@ static int hwpoison_pte_range(pmd_t *pmdp, unsigned long addr, { struct hwp_walk *hwp = (struct hwp_walk *)walk->private; int ret = 0; - pte_t *ptep; + pte_t *ptep, *mapped_pte; spinlock_t *ptl; ptl = pmd_trans_huge_lock(pmdp, walk->vma); @@ -645,14 +645,15 @@ static int hwpoison_pte_range(pmd_t *pmdp, unsigned long addr, if (pmd_trans_unstable(pmdp)) goto out; - ptep = pte_offset_map_lock(walk->vma->vm_mm, pmdp, addr, &ptl); + mapped_pte = ptep = pte_offset_map_lock(walk->vma->vm_mm, pmdp, + addr, &ptl); for (; addr != end; ptep++, addr += PAGE_SIZE) { ret = check_hwpoisoned_entry(*ptep, addr, PAGE_SHIFT, hwp->pfn, &hwp->tk); if (ret == 1) break; } - pte_unmap_unlock(ptep - 1, ptl); + pte_unmap_unlock(mapped_pte, ptl); out: cond_resched(); return ret; -- 2.23.0