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=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 34C59C352A3 for ; Mon, 10 Feb 2020 12:38:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 061502085B for ; Mon, 10 Feb 2020 12:38:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338338; bh=8u5vfo0W6dwew4wkxSb7nqRjuWXE9FNdYdLLyBEAE/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2Q+zdDVFbUZRaC8JcJlIiDH3GDGbzSrLdU6iwXUOXd8bqmgkb99jkt/HHwtv1DNYA bFTrqtyIr1C12Qj0/c7bseoczBz97RcyGreJY79YqU6pqJBcFPKkQrHjHTHB1HzdED D85nlt8U1b7xTWkMkPX9MMJETrCr/2mxO00XKOm8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729276AbgBJMi4 (ORCPT ); Mon, 10 Feb 2020 07:38:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:58268 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728094AbgBJMhM (ORCPT ); Mon, 10 Feb 2020 07:37:12 -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 B591520661; Mon, 10 Feb 2020 12:37:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338231; bh=8u5vfo0W6dwew4wkxSb7nqRjuWXE9FNdYdLLyBEAE/Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jyu1VzRKK3ndX7scbQLs04EUSl/ZSGe/lO2RCTTQZd/YHn25m7JW9zjfF0NeZ43M2 6bAmkBZ29BemFwVuk2poW1akFBV0KFXX8blCQiNOa37FIhAOd01kYkq4vtAywF748o SrIZXlgduh2mL6dV8UFL6u8epyTIehoDUR0InkNs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Michael Ellerman Subject: [PATCH 5.4 075/309] powerpc/ptdump: Fix W+X verification Date: Mon, 10 Feb 2020 04:30:31 -0800 Message-Id: <20200210122413.072268305@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122406.106356946@linuxfoundation.org> References: <20200210122406.106356946@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",