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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 2A0C3C433F4 for ; Wed, 29 Aug 2018 02:18:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C82AF2087C for ; Wed, 29 Aug 2018 02:18:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C82AF2087C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727187AbeH2GMb (ORCPT ); Wed, 29 Aug 2018 02:12:31 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:44194 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725882AbeH2GMb (ORCPT ); Wed, 29 Aug 2018 02:12:31 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A1117B5CA; Wed, 29 Aug 2018 02:18:00 +0000 (UTC) Received: from 192.168.1.2 (ovpn-8-16.pek2.redhat.com [10.72.8.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 011782026D6B; Wed, 29 Aug 2018 02:17:56 +0000 (UTC) From: Baoquan He To: tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com, thgarnie@google.com, kirill.shutemov@linux.intel.com Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Baoquan He Subject: [PATCH 1/2] x86/mm/KASLR: Fix the wrong calculation of kalsr region initial size Date: Wed, 29 Aug 2018 10:17:53 +0800 Message-Id: <20180829021754.21850-1-bhe@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 29 Aug 2018 02:18:00 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Wed, 29 Aug 2018 02:18:00 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'bhe@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In memory KASLR, __PHYSICAL_MASK_SHIFT is taken to calculate the initial size of the direct mapping region. This is right in the old code where __PHYSICAL_MASK_SHIFT was equal to MAX_PHYSMEM_BITS, 46bit, and only 4-level mode was supported. Later, in commit: b83ce5ee91471d ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52"), __PHYSICAL_MASK_SHIFT was changed to be 52 always, no matter it's 5-level or 4-level. This is wrong for 4-level paging. Then when adapt phyiscal memory region size based on available memory, it will overflow if the amount of system RAM and the padding is bigger than 64TB. In fact, here MAX_PHYSMEM_BITS should be used instead. Fix it by by replacing __PHYSICAL_MASK_SHIFT with MAX_PHYSMEM_BITS. Signed-off-by: Baoquan He --- arch/x86/mm/kaslr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c index 61db77b0eda9..0988971069c9 100644 --- a/arch/x86/mm/kaslr.c +++ b/arch/x86/mm/kaslr.c @@ -93,7 +93,7 @@ void __init kernel_randomize_memory(void) if (!kaslr_memory_enabled()) return; - kaslr_regions[0].size_tb = 1 << (__PHYSICAL_MASK_SHIFT - TB_SHIFT); + kaslr_regions[0].size_tb = 1 << (MAX_PHYSMEM_BITS - TB_SHIFT); kaslr_regions[1].size_tb = VMALLOC_SIZE_TB; /* -- 2.13.6