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,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 EE81DECDE5F for ; Thu, 19 Jul 2018 23:32:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACAE820673 for ; Thu, 19 Jul 2018 23:32:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ACAE820673 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.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 S1731262AbeGTAR1 (ORCPT ); Thu, 19 Jul 2018 20:17:27 -0400 Received: from terminus.zytor.com ([198.137.202.136]:52165 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728087AbeGTAR1 (ORCPT ); Thu, 19 Jul 2018 20:17:27 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w6JNV4lM2453829 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 19 Jul 2018 16:31:04 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w6JNV4nG2453824; Thu, 19 Jul 2018 16:31:04 -0700 Date: Thu, 19 Jul 2018 16:31:04 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Joerg Roedel Message-ID: Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, bp@alien8.de, dave.hansen@intel.com, boris.ostrovsky@oracle.com, jpoimboe@redhat.com, brgerst@gmail.com, David.Laight@aculab.com, jkosina@suse.cz, pavel@ucw.cz, tglx@linutronix.de, dvlasenk@redhat.com, dhgutteridge@sympatico.ca, jroedel@suse.de, hpa@zytor.com, llong@redhat.com, peterz@infradead.org, aarcange@redhat.com, eduval@amazon.com, jgross@suse.com, mingo@kernel.org, will.deacon@arm.com, gregkh@linuxfoundation.org, luto@kernel.org Reply-To: hpa@zytor.com, jroedel@suse.de, eduval@amazon.com, llong@redhat.com, aarcange@redhat.com, peterz@infradead.org, jgross@suse.com, will.deacon@arm.com, luto@kernel.org, gregkh@linuxfoundation.org, mingo@kernel.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, bp@alien8.de, dave.hansen@intel.com, boris.ostrovsky@oracle.com, David.Laight@aculab.com, jkosina@suse.cz, jpoimboe@redhat.com, brgerst@gmail.com, tglx@linutronix.de, pavel@ucw.cz, dhgutteridge@sympatico.ca, dvlasenk@redhat.com In-Reply-To: <1531906876-13451-25-git-send-email-joro@8bytes.org> References: <1531906876-13451-25-git-send-email-joro@8bytes.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/pti] x86/mm/pti: Add an overflow check to pti_clone_pmds() Git-Commit-ID: 935232ce28dfabff1171e5a7113b2d865fa9ee63 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 935232ce28dfabff1171e5a7113b2d865fa9ee63 Gitweb: https://git.kernel.org/tip/935232ce28dfabff1171e5a7113b2d865fa9ee63 Author: Joerg Roedel AuthorDate: Wed, 18 Jul 2018 11:41:01 +0200 Committer: Thomas Gleixner CommitDate: Fri, 20 Jul 2018 01:11:43 +0200 x86/mm/pti: Add an overflow check to pti_clone_pmds() The addr counter will overflow if the last PMD of the address space is cloned, resulting in an endless loop. Check for that and bail out of the loop when it happens. Signed-off-by: Joerg Roedel Signed-off-by: Thomas Gleixner Tested-by: Pavel Machek Cc: "H . Peter Anvin" Cc: linux-mm@kvack.org Cc: Linus Torvalds Cc: Andy Lutomirski Cc: Dave Hansen Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Peter Zijlstra Cc: Borislav Petkov Cc: Jiri Kosina Cc: Boris Ostrovsky Cc: Brian Gerst Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Cc: Andrea Arcangeli Cc: Waiman Long Cc: "David H . Gutteridge" Cc: joro@8bytes.org Link: https://lkml.kernel.org/r/1531906876-13451-25-git-send-email-joro@8bytes.org --- arch/x86/mm/pti.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 71fba17c9d7c..79217868dd13 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -297,6 +297,10 @@ pti_clone_pmds(unsigned long start, unsigned long end, pmdval_t clear) p4d_t *p4d; pud_t *pud; + /* Overflow check */ + if (addr < start) + break; + pgd = pgd_offset_k(addr); if (WARN_ON(pgd_none(*pgd))) return;