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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 4CACBCA9EAC for ; Sat, 19 Oct 2019 03:20:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 02E7722459 for ; Sat, 19 Oct 2019 03:20:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="wV2bVCa4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 02E7722459 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A96E48E0013; Fri, 18 Oct 2019 23:20:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A46CA8E0003; Fri, 18 Oct 2019 23:20:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 95CB08E0013; Fri, 18 Oct 2019 23:20:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0229.hostedemail.com [216.40.44.229]) by kanga.kvack.org (Postfix) with ESMTP id 740298E0003 for ; Fri, 18 Oct 2019 23:20:07 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 26FA11803006C for ; Sat, 19 Oct 2019 03:20:07 +0000 (UTC) X-FDA: 76059080454.03.store08_1e18e1502a23c X-HE-Tag: store08_1e18e1502a23c X-Filterd-Recvd-Size: 3348 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Sat, 19 Oct 2019 03:20:06 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 778D32245A; Sat, 19 Oct 2019 03:20:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571455205; bh=QGcY+R8WdQTLLhix30lDEMJ+sG1VSyhWy0K+M9oeQxI=; h=Date:From:To:Subject:From; b=wV2bVCa4k0DTS2V/5tlCoGVcggRtDghN5Wqv9pTVIkqWDhmfUtpDYVka+rJGOUDW1 54uoaH9p5ywdKdt3nVwZNgapPu9tK7i3lIPoxGAcpqWXK21ASDnvYvUi14aIpugpxQ j0DCCgxpk7776o8o6zqzTZxEKLgmVI0XvfUnyzIQ= Date: Fri, 18 Oct 2019 20:20:05 -0700 From: akpm@linux-foundation.org To: akpm@linux-foundation.org, anshuman.khandual@arm.com, david@redhat.com, linux-mm@kvack.org, mhocko@kernel.org, mhocko@suse.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, stable@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 14/26] hugetlbfs: don't access uninitialized memmaps in pfn_range_valid_gigantic() Message-ID: <20191019032005.sgsUejgDW%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: David Hildenbrand Subject: hugetlbfs: don't access uninitialized memmaps in pfn_range_valid_gigantic() Uninitialized memmaps contain garbage and in the worst case trigger kernel BUGs, especially with CONFIG_PAGE_POISONING. They should not get touched. Let's make sure that we only consider online memory (managed by the buddy) that has initialized memmaps. ZONE_DEVICE is not applicable. page_zone() will call page_to_nid(), which will trigger VM_BUG_ON_PGFLAGS(PagePoisoned(page), page) with CONFIG_PAGE_POISONING and CONFIG_DEBUG_VM_PGFLAGS when called on uninitialized memmaps. This can be the case when an offline memory block (e.g., never onlined) is spanned by a zone. Note: As explained by Michal in [1], alloc_contig_range() will verify the range. So it boils down to the wrong access in this function. [1] http://lkml.kernel.org/r/20180423000943.GO17484@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20191015120717.4858-1-david@redhat.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319] Signed-off-by: David Hildenbrand Reported-by: Michal Hocko Acked-by: Michal Hocko Reviewed-by: Mike Kravetz Cc: Anshuman Khandual Cc: [4.13+] Signed-off-by: Andrew Morton --- mm/hugetlb.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/mm/hugetlb.c~hugetlbfs-dont-access-uninitialized-memmaps-in-pfn_range_valid_gigantic +++ a/mm/hugetlb.c @@ -1084,11 +1084,10 @@ static bool pfn_range_valid_gigantic(str struct page *page; for (i = start_pfn; i < end_pfn; i++) { - if (!pfn_valid(i)) + page = pfn_to_online_page(i); + if (!page) return false; - page = pfn_to_page(i); - if (page_zone(page) != z) return false; _