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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 E276FC4BA21 for ; Wed, 26 Feb 2020 21:50:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF85A24670 for ; Wed, 26 Feb 2020 21:50:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727695AbgBZVum (ORCPT ); Wed, 26 Feb 2020 16:50:42 -0500 Received: from mail-qk1-f196.google.com ([209.85.222.196]:42717 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727503AbgBZVum (ORCPT ); Wed, 26 Feb 2020 16:50:42 -0500 Received: by mail-qk1-f196.google.com with SMTP id o28so1104740qkj.9 for ; Wed, 26 Feb 2020 13:50:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=bVvtoF3dBwjUAYtU4MtEeTRU2gPLqCEKNNfUILCYJ2w=; b=kGMXdz8RsI8BmUG5Z5gl5QRP+Bd48MZg+8N9So7ujcCno6UgK+3a8HqpIvbXl2SC6/ bamzBRZWzCuGtRqYCEPdlUEbEQkdq1s/qVjOsPjiLTlRGhRHdkMzYTt9k5VdK0HSz1j6 35mGRRjwu2JdhVCEresCRwoW/RDlf6l3af3/0DW4HQ6AmeFIHebZBGDDMONW5BSkB48v jNfJln14QANgjYgdurlWIshvnZ2bA5WreUfdGt67S88fWEfNMyrIeMsTlR1TiZYTfwm3 cGlevCt9h4fAt5baN3zS1kPPqzd4rZTcZfR6k08XIsI6iSL4JEO0zd5OzG7XjlBXpy1d vw6Q== X-Gm-Message-State: APjAAAXPq6I5hrBTPWaRLu3zuqpQXE7wQ24xAIROzjxm1GnCpaUzw8RD KPeFFSTEjEmceWFyDm9LqrE= X-Google-Smtp-Source: APXvYqx8UV8YjcThLwuE4pseSIhWF+wgUfrcRuFfFy2RgtZSG7vFhqozsjyBFIY3a73ZGyacvn9lUA== X-Received: by 2002:a37:4e97:: with SMTP id c145mr1416125qkb.253.1582753841181; Wed, 26 Feb 2020 13:50:41 -0800 (PST) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id y62sm1877659qka.19.2020.02.26.13.50.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 Feb 2020 13:50:40 -0800 (PST) From: Arvind Sankar To: "Tobin C . Harding" , Tycho Andersen Cc: kernel-hardening@lists.openwall.com, Dave Hansen , Andy Lutomirski , Peter Zijlstra , x86@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] x86/mm/init_32: Don't print out kernel memory layout if KASLR Date: Wed, 26 Feb 2020 16:50:39 -0500 Message-Id: <20200226215039.2842351-1-nivedita@alum.mit.edu> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For security, only show the virtual kernel memory layout if KASLR is disabled. Signed-off-by: Arvind Sankar --- arch/x86/mm/init_32.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 23df4885bbed..53635be69102 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -788,6 +788,10 @@ void __init mem_init(void) x86_init.hyper.init_after_bootmem(); mem_init_print_info(NULL); + + if (kaslr_enabled()) + goto skip_layout; + printk(KERN_INFO "virtual kernel memory layout:\n" " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n" " cpu_entry : 0x%08lx - 0x%08lx (%4ld kB)\n" @@ -827,6 +831,7 @@ void __init mem_init(void) (unsigned long)&_text, (unsigned long)&_etext, ((unsigned long)&_etext - (unsigned long)&_text) >> 10); +skip_layout: /* * Check boundaries twice: Some fundamental inconsistencies can * be detected at build time already. -- 2.24.1