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=-8.8 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 3BFE7C4360F for ; Wed, 13 Feb 2019 22:42:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BA84222D0 for ; Wed, 13 Feb 2019 22:42:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qXZ2Vu+P" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395227AbfBMWmg (ORCPT ); Wed, 13 Feb 2019 17:42:36 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:33956 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2395185AbfBMWmc (ORCPT ); Wed, 13 Feb 2019 17:42:32 -0500 Received: by mail-wr1-f65.google.com with SMTP id f14so4414094wrg.1; Wed, 13 Feb 2019 14:42:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references:reply-to :mime-version:content-transfer-encoding; bh=hKpBmvKhY62YcE+qk2JyFeoOHJdEVTVCpq3mJ7wKHeo=; b=qXZ2Vu+P6kthMEkjo4iNmgotT7rvJqsgrxxwiFIZl81jupiKBpLSUH2abdTiMlSLJs YahkFPUw4qFNOTutD7eS0RkUg8/4x71BFfYo03YVardx8EzGJKYPhLTp7k9S+a53JLMv M0pdfY2WiUJrH05PCxiQNB/qHgXxlZuJ3TU+QrEu0FcGIo457jatHpc7OPuJqaa9AZl6 RGP/Zel8+olUZCL6uwyRtRpnAnITyKhXcOeL8t64zoh8KvFaWjZqdhMCNOoDamFRVbxm WFsxWPvhhEzgW6QvSW1k6TbPE36aOAgqq9OpmuIO5LEScw602S7o8oXyO3Tc0d4i2nNa pjag== 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:in-reply-to :references:reply-to:mime-version:content-transfer-encoding; bh=hKpBmvKhY62YcE+qk2JyFeoOHJdEVTVCpq3mJ7wKHeo=; b=AdeS86nrwvnGRsPWHCm6nevP1UA/TuwDy7BJ8NYP9yhi/o0e8KudH6WS91jQeuN1u8 hsMHKWzVVHwB76L90Vf1I9Umz3EqQox+anIeGK/SSlzI32o3CY+uh/t+5enIE9Lb7Kr0 7U0cZpUPVIXwQS8vxTMDlEDKWah+2t/5EF88fp5byXnW4yG5xjV5wGQZFKoTO6+MrRSs 6lY9cd8ppnV3eUlfMxbTqzpuAQkVB4NNQpGVkbnUpMMQJbXIttS8+OCMs5/OEx4WQG3c CPZg0D3FHhpuHvh72WX7wcmXNfUVmjCXQHYVNSGc/4MaB0XIJCW6JAUhSh4uwh3NP8EB O0aQ== X-Gm-Message-State: AHQUAubH1BTYgkuTh0QnDvSXKbMWOWF9yGDU9ZOehDQyCfk8BMUKdSv2 1Mi4hGhyayO7l0icVwFSZMI= X-Google-Smtp-Source: AHgI3IawnVj1KBrwvlzP2l4yYPQzxhp3IgPK38fpbbnsPGtbn+e/GwYjxoGB2EAAlzWjGvPfKesd0w== X-Received: by 2002:a5d:538a:: with SMTP id d10mr283768wrv.121.1550097750621; Wed, 13 Feb 2019 14:42:30 -0800 (PST) Received: from localhost.localdomain ([91.75.74.250]) by smtp.gmail.com with ESMTPSA id f196sm780810wme.36.2019.02.13.14.42.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 13 Feb 2019 14:42:30 -0800 (PST) From: Igor Stoppa X-Google-Original-From: Igor Stoppa Cc: Igor Stoppa , Andy Lutomirski , Nadav Amit , Matthew Wilcox , Peter Zijlstra , Kees Cook , Dave Hansen , Mimi Zohar , Thiago Jung Bauermann , Ahmed Soliman , linux-integrity@vger.kernel.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v5 10/12] __wr_after_init: rodata_test: test __wr_after_init Date: Thu, 14 Feb 2019 00:41:39 +0200 Message-Id: X-Mailer: git-send-email 2.19.1 In-Reply-To: References: Reply-To: Igor Stoppa MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: unlisted-recipients:; (no To-header on input) Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The write protection of the __wr_after_init data can be verified with the same methodology used for const data. Signed-off-by: Igor Stoppa CC: Andy Lutomirski CC: Nadav Amit CC: Matthew Wilcox CC: Peter Zijlstra CC: Kees Cook CC: Dave Hansen CC: Mimi Zohar CC: Thiago Jung Bauermann CC: Ahmed Soliman CC: linux-integrity@vger.kernel.org CC: kernel-hardening@lists.openwall.com CC: linux-mm@kvack.org CC: linux-kernel@vger.kernel.org --- mm/rodata_test.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/mm/rodata_test.c b/mm/rodata_test.c index e1349520b436..a669cf9f5a61 100644 --- a/mm/rodata_test.c +++ b/mm/rodata_test.c @@ -16,8 +16,23 @@ #define INIT_TEST_VAL 0xC3 +/* + * Note: __ro_after_init data is, for every practical effect, equivalent to + * const data, since they are even write protected at the same time; there + * is no need for separate testing. + * __wr_after_init data, otoh, is altered also after the write protection + * takes place and it cannot be exploitable for altering more permanent + * data. + */ + static const int rodata_test_data = INIT_TEST_VAL; +#ifdef CONFIG_PRMEM +static int wr_after_init_test_data __wr_after_init = INIT_TEST_VAL; +extern long __start_wr_after_init; +extern long __end_wr_after_init; +#endif + static bool test_data(char *data_type, const int *data, unsigned long start, unsigned long end) { @@ -59,7 +74,13 @@ static bool test_data(char *data_type, const int *data, void rodata_test(void) { - test_data("rodata", &rodata_test_data, - (unsigned long)&__start_rodata, - (unsigned long)&__end_rodata); + if (!test_data("rodata", &rodata_test_data, + (unsigned long)&__start_rodata, + (unsigned long)&__end_rodata)) + return; +#ifdef CONFIG_PRMEM + test_data("wr after init data", &wr_after_init_test_data, + (unsigned long)&__start_wr_after_init, + (unsigned long)&__end_wr_after_init); +#endif } -- 2.19.1