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=-6.8 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,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 A6D91CA9EAF for ; Sun, 27 Oct 2019 21:32:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7977320717 for ; Sun, 27 Oct 2019 21:32:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572211922; bh=DBvde18xu0b7T6PFX7Da40x3Js9/MlrRtGfYxpnYZJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=03l5VcCC2VfQ7nzx6SeqwZeDxRC9NES+bQJyKEcIoy1hRbWm3nuXV7ZbJs6QQOI2/ Mzk7dgxjFsp6mPtSDh2zlECa7BZ+w/pVz73bHLXEMHNUc5za68Gsa08WrNRyO+2Zxl 7qhmyOqPWkgJ4AYz9ySMLmb11CGWgjSO/UTJP7EQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730695AbfJ0VPr (ORCPT ); Sun, 27 Oct 2019 17:15:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:35098 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730673AbfJ0VPl (ORCPT ); Sun, 27 Oct 2019 17:15:41 -0400 Received: from localhost (100.50.158.77.rev.sfr.net [77.158.50.100]) (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 D901E20B7C; Sun, 27 Oct 2019 21:15:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572210940; bh=DBvde18xu0b7T6PFX7Da40x3Js9/MlrRtGfYxpnYZJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z0vYvpff2W3tkGZG8JkemsCvzo45K5c7IOFG8mzQnh59JptbFBtJdFpm4sA9iI8qo NX5NQhWDWoOHKh0nLoz55Hxkt4dvMNy+GuEJmAuzFJq9ug1AHcxmLDkySaE3IXdz0/ 0145v/QoE6RQYrFVaIlOOTW4S24UIrrju2ZtJub4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Hildenbrand , Michal Hocko , Michal Hocko , Mike Kravetz , Anshuman Khandual , Andrew Morton , Linus Torvalds Subject: [PATCH 4.19 68/93] hugetlbfs: dont access uninitialized memmaps in pfn_range_valid_gigantic() Date: Sun, 27 Oct 2019 22:01:20 +0100 Message-Id: <20191027203308.085426069@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191027203251.029297948@linuxfoundation.org> References: <20191027203251.029297948@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Hildenbrand commit f231fe4235e22e18d847e05cbe705deaca56580a upstream. 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 Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1073,11 +1073,10 @@ 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;