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,USER_AGENT_GIT autolearn=unavailable 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 F4208CA9EBD for ; Sun, 27 Oct 2019 21:27:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C18F7222BE for ; Sun, 27 Oct 2019 21:27:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572211653; bh=3v2CFzO8u+SwFTSx3GvJ7V2Rq8W5YnaxDv4MV1yXFjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nJhVpT7jYrmN12IwV7wWo2aMGaHr42dGtM8+Xn9+qBvrhfByrIuZ5vUm10pMDbc8p 1JG+N4ZmXW97nK22Tbw2aQHP7T/cfRMfBuQCvVNPB3iBuEkZ3Qptxz5JalvzjOi3qL C5JFfhsmCK46QD/gsAlCzzjfrxoN13zIuNyAUNv0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731773AbfJ0VZE (ORCPT ); Sun, 27 Oct 2019 17:25:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:46720 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732634AbfJ0VZB (ORCPT ); Sun, 27 Oct 2019 17:25:01 -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 0F29221848; Sun, 27 Oct 2019 21:24:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572211500; bh=3v2CFzO8u+SwFTSx3GvJ7V2Rq8W5YnaxDv4MV1yXFjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RFN7OwTOR+nPTbeHxx0iegMIZGOiGeeTqLXbJT0UdKTH+1aGKrjWjvwMUF8QHv8oC ADknZ5a7f0pTmqEOZeBZ5Gj/xK7rpMybYJ1S5thHtcp83T+nOIZb5JQCNKKMFeBakT 5rSgFcYbrkhYZ8V6Ll4cjN4MFoEcEJ1H9CkdKP74= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Hildenbrand , Naoya Horiguchi , Michal Hocko , "Rafael J. Wysocki" , Andrew Morton , Linus Torvalds Subject: [PATCH 5.3 136/197] drivers/base/memory.c: dont access uninitialized memmaps in soft_offline_page_store() Date: Sun, 27 Oct 2019 22:00:54 +0100 Message-Id: <20191027203359.053510896@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191027203351.684916567@linuxfoundation.org> References: <20191027203351.684916567@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: David Hildenbrand commit 641fe2e9387a36f9ee01d7c69382d1fe147a5e98 upstream. Uninitialized memmaps contain garbage and in the worst case trigger kernel BUGs, especially with CONFIG_PAGE_POISONING. They should not get touched. Right now, when trying to soft-offline a PFN that resides on a memory block that was never onlined, one gets a misleading error with CONFIG_PAGE_POISONING: :/# echo 5637144576 > /sys/devices/system/memory/soft_offline_page [ 23.097167] soft offline: 0x150000 page already poisoned But the actual result depends on the garbage in the memmap. soft_offline_page() can only work with online pages, it returns -EIO in case of ZONE_DEVICE. Make sure to only forward pages that are online (iow, managed by the buddy) and, therefore, have an initialized memmap. Add a check against pfn_to_online_page() and similarly return -EIO. Link: http://lkml.kernel.org/r/20191010141200.8985-1-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 Acked-by: Naoya Horiguchi Acked-by: Michal Hocko Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Cc: [4.13+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/base/memory.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -554,6 +554,9 @@ static ssize_t soft_offline_page_store(s pfn >>= PAGE_SHIFT; if (!pfn_valid(pfn)) return -ENXIO; + /* Only online pages can be soft-offlined (esp., not ZONE_DEVICE). */ + if (!pfn_to_online_page(pfn)) + return -EIO; ret = soft_offline_page(pfn_to_page(pfn), 0); return ret == 0 ? count : ret; }