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 BAB38C352A3 for ; Mon, 10 Feb 2020 13:06:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8A3AF20708 for ; Mon, 10 Feb 2020 13:06:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581339993; bh=8u5vfo0W6dwew4wkxSb7nqRjuWXE9FNdYdLLyBEAE/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=aAtQcdZ8WC7zHVsQSK99Q+Vsz8WGnsLzJN/fiV7UBy0MDA0Sd8bM7caDXjz2XjJMx 3cJhT/cH6fPxqwzzz5I0Tw97tv3Ln35X19WS0m18wdvTFKf6wEKBnS2yZt/3q6ooRN n3DA+H9cVyyFfDdpAaLHMyAX2sZ+RMxzxVJCIOow= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730600AbgBJNGc (ORCPT ); Mon, 10 Feb 2020 08:06:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:38534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729554AbgBJMjx (ORCPT ); Mon, 10 Feb 2020 07:39:53 -0500 Received: from localhost (unknown [209.37.97.194]) (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 1C17B208C4; Mon, 10 Feb 2020 12:39:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338392; bh=8u5vfo0W6dwew4wkxSb7nqRjuWXE9FNdYdLLyBEAE/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MdYmF6REsu87ZdFwirY0MaiYf5Ertsfb6A1aDtLNs/yKoWkZKgl7DuUSK64RAMzBg 0dnH0E6Fcw3raSHVSEIuAdPOH3BCBE4iqnKKI3V0P/UxZxf5n/12bD2VtJrLlJo/2J KT3yWGTg93iS/HCJjnpte2G6l/3QqcVmeB/wb4sQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Michael Ellerman Subject: [PATCH 5.5 084/367] powerpc/ptdump: Fix W+X verification Date: Mon, 10 Feb 2020 04:29:57 -0800 Message-Id: <20200210122432.102362739@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122423.695146547@linuxfoundation.org> References: <20200210122423.695146547@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: Christophe Leroy commit d80ae83f1f932ab7af47b54d0d3bef4f4dba489f upstream. Verification cannot rely on simple bit checking because on some platforms PAGE_RW is 0, checking that a page is not W means checking that PAGE_RO is set instead of checking that PAGE_RW is not set. Use pte helpers instead of checking bits. Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/0d894839fdbb19070f0e1e4140363be4f2bb62fc.1578989540.git.christophe.leroy@c-s.fr Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/mm/ptdump/ptdump.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/arch/powerpc/mm/ptdump/ptdump.c +++ b/arch/powerpc/mm/ptdump/ptdump.c @@ -173,10 +173,12 @@ static void dump_addr(struct pg_state *s static void note_prot_wx(struct pg_state *st, unsigned long addr) { + pte_t pte = __pte(st->current_flags); + if (!IS_ENABLED(CONFIG_PPC_DEBUG_WX) || !st->check_wx) return; - if (!((st->current_flags & pgprot_val(PAGE_KERNEL_X)) == pgprot_val(PAGE_KERNEL_X))) + if (!pte_write(pte) || !pte_exec(pte)) return; WARN_ONCE(1, "powerpc/mm: Found insecure W+X mapping at address %p/%pS\n",