From patchwork Tue Jan 12 09:34:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 361796 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=-13.8 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 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 D1EE6C433E0 for ; Tue, 12 Jan 2021 09:36:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7AB5523105 for ; Tue, 12 Jan 2021 09:36:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392716AbhALJfk (ORCPT ); Tue, 12 Jan 2021 04:35:40 -0500 Received: from mga18.intel.com ([134.134.136.126]:57028 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392715AbhALJfk (ORCPT ); Tue, 12 Jan 2021 04:35:40 -0500 IronPort-SDR: 7L535RC0Cs7jRkuW4IZTaH24Nnh6R5tGbXmrRZgKZKBQEnU09Ifv4pr3Cw5v/yRRfMBxYoNdto 9Shj7uCDeDXQ== X-IronPort-AV: E=McAfee;i="6000,8403,9861"; a="165691367" X-IronPort-AV: E=Sophos;i="5.79,341,1602572400"; d="scan'208";a="165691367" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2021 01:34:59 -0800 IronPort-SDR: 4TSrFpjxdyLfaLml0thLClygScVZvIKkcaXY0+AZZr2Jl3jmQhCIG29P4PmSL8NQX5bZfRWq/5 4B8qgPvs6sjw== X-IronPort-AV: E=Sophos;i="5.79,341,1602572400"; d="scan'208";a="571641600" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.25]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2021 01:34:58 -0800 Subject: [PATCH v2 4/5] mm: Fix page reference leak in soft_offline_page() From: Dan Williams To: linux-mm@kvack.org Cc: Andrew Morton , Naoya Horiguchi , David Hildenbrand , Michal Hocko , Oscar Salvador , stable@vger.kernel.org, vishal.l.verma@intel.com, linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org Date: Tue, 12 Jan 2021 01:34:58 -0800 Message-ID: <161044409809.1482714.11965583624142790079.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <161044407603.1482714.16630477578392768273.stgit@dwillia2-desk3.amr.corp.intel.com> References: <161044407603.1482714.16630477578392768273.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The conversion to move pfn_to_online_page() internal to soft_offline_page() missed that the get_user_pages() reference needs to be dropped when pfn_to_online_page() fails. When soft_offline_page() is handed a pfn_valid() && !pfn_to_online_page() pfn the kernel hangs at dax-device shutdown due to a leaked reference. Fixes: feec24a6139d ("mm, soft-offline: convert parameter to pfn") Cc: Andrew Morton Cc: Naoya Horiguchi Cc: David Hildenbrand Cc: Michal Hocko Cc: Oscar Salvador Cc: Signed-off-by: Dan Williams Reviewed-by: David Hildenbrand --- mm/memory-failure.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 5a38e9eade94..78b173c7190c 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1885,6 +1885,12 @@ static int soft_offline_free_page(struct page *page) return rc; } +static void put_ref_page(struct page *page) +{ + if (page) + put_page(page); +} + /** * soft_offline_page - Soft offline a page. * @pfn: pfn to soft-offline @@ -1910,20 +1916,26 @@ static int soft_offline_free_page(struct page *page) int soft_offline_page(unsigned long pfn, int flags) { int ret; - struct page *page; bool try_again = true; + struct page *page, *ref_page = NULL; + + WARN_ON_ONCE(!pfn_valid(pfn) && (flags & MF_COUNT_INCREASED)); if (!pfn_valid(pfn)) return -ENXIO; + if (flags & MF_COUNT_INCREASED) + ref_page = pfn_to_page(pfn); + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */ page = pfn_to_online_page(pfn); - if (!page) + if (!page) { + put_ref_page(ref_page); return -EIO; + } if (PageHWPoison(page)) { pr_info("%s: %#lx page already poisoned\n", __func__, pfn); - if (flags & MF_COUNT_INCREASED) - put_page(page); + put_ref_page(ref_page); return 0; }