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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 B9CEDC3A5A6 for ; Sun, 22 Sep 2019 18:56:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8838421907 for ; Sun, 22 Sep 2019 18:56:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569178583; bh=LyoWdA0f7wwBcvyqosMNHJUlyBRTJxT4ByefN/vA58U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dnk7XJictaPNtrxdwJdRrQajkP2MMpeOTzKGSl+eqU2fafpqWZARwMrUv2OxJxNEI 7sUWjf3zdmHKR0e7zAGHZc26BRncYHj0e6SohNbNxz2aPLW/4ELUXQlZA6WyyVbn7c tV1z4fIzRVgrsbRPKrme66tK20vslMuIzyUlX1ys= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2438570AbfIVS4W (ORCPT ); Sun, 22 Sep 2019 14:56:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:58340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2438556AbfIVS4V (ORCPT ); Sun, 22 Sep 2019 14:56:21 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B527E2186A; Sun, 22 Sep 2019 18:56:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569178580; bh=LyoWdA0f7wwBcvyqosMNHJUlyBRTJxT4ByefN/vA58U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JisylMhPPVmeM7+0SzUQNT8MyU+GzSJXXtsC2WV9aldeJs/MELyS4+E4fnj8+XRor tS1sCGmqgYwh5YLvm6amjjzf+Kz7/ezR+uNNFdz7AQQ9cy/2mLR1BFbpGjDuMD7tcE Q/gBOczVZ/s707AP4vOyd2aUxHZhWNb8WAojyR5E= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Song Liu , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Sasha Levin Subject: [PATCH AUTOSEL 4.19 090/128] x86/mm/pti: Handle unaligned address gracefully in pti_clone_pagetable() Date: Sun, 22 Sep 2019 14:53:40 -0400 Message-Id: <20190922185418.2158-90-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190922185418.2158-1-sashal@kernel.org> References: <20190922185418.2158-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 c1ba376484a5b..622d5968c9795 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -338,13 +338,15 @@ 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