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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 BD9D5C10F14 for ; Thu, 3 Oct 2019 16:46:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 885F720867 for ; Thu, 3 Oct 2019 16:46:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570121169; bh=YdtB9ERDjqPMpLb1hhSKMnEGtL5LAfOBUuAxVN22O04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PSPIYDdwXSkFEHx8tlMZuGqZTcp+LT34K/W0g1aZHUWLkOooeGbwVPABoYk7IjyPv WPOKziOJWurqjhZ1wNC2vFhMVrX0oeVy9jLbNrmtZWmeGTETM+S6Wb3jLKfDPEPNfJ MX3T6D5AYo3ik10JhD9W9/op9K34K/iguPJxLHdc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405127AbfJCQqJ (ORCPT ); Thu, 3 Oct 2019 12:46:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:59122 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404899AbfJCQqG (ORCPT ); Thu, 3 Oct 2019 12:46:06 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 A8AFC215EA; Thu, 3 Oct 2019 16:46:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570121165; bh=YdtB9ERDjqPMpLb1hhSKMnEGtL5LAfOBUuAxVN22O04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qpMRVHCSHStTrqP21Lx18FExnzOfxLq0wbhu8hka0rM8+Thse1Mt0c+Bf5HrkLoJq Q0m6wA1QqTAIeWyrbTI1lkAIY+vlHY00RwqtfHdCELxfbhnpM8OZsZm9dV8lcfaCCC 4iQnWSU/PgEA8OwuiFtptrwWcqYs40ng8Lec+OI4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Song Liu , Thomas Gleixner , Ingo Molnar , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 5.3 177/344] x86/mm/pti: Handle unaligned address gracefully in pti_clone_pagetable() Date: Thu, 3 Oct 2019 17:52:22 +0200 Message-Id: <20191003154557.695271051@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154540.062170222@linuxfoundation.org> References: <20191003154540.062170222@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: Song Liu [ Upstream commit 825d0b73cd7526b0bb186798583fae810091cbac ] pti_clone_pmds() assumes that the supplied address is either: - properly PUD/PMD aligned or - the address is actually mapped which means that independently of the mapping level (PUD/PMD/PTE) the next higher mapping exists. If that's not the case the unaligned address can be incremented by PUD or PMD size incorrectly. All callers supply mapped and/or aligned addresses, but for the sake of robustness it's better to handle that case properly and to emit a warning. [ tglx: Rewrote changelog and added WARN_ON_ONCE() ] Signed-off-by: Song Liu Signed-off-by: Thomas Gleixner Reviewed-by: Ingo Molnar Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908282352470.1938@nanos.tec.linutronix.de Signed-off-by: Sasha Levin --- arch/x86/mm/pti.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index ba22b50f4eca2..7f2140414440d 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -330,13 +330,15 @@ pti_clone_pgtable(unsigned long start, unsigned long end, pud = pud_offset(p4d, addr); if (pud_none(*pud)) { - addr += PUD_SIZE; + WARN_ON_ONCE(addr & ~PUD_MASK); + addr = round_up(addr + 1, PUD_SIZE); continue; } pmd = pmd_offset(pud, addr); if (pmd_none(*pmd)) { - addr += PMD_SIZE; + WARN_ON_ONCE(addr & ~PMD_MASK); + addr = round_up(addr + 1, PMD_SIZE); continue; } -- 2.20.1