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 298CDC43381 for ; Wed, 13 Feb 2019 22:43:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE8E2222CF for ; Wed, 13 Feb 2019 22:43:03 +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="NjIzVPkQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395147AbfBMWm1 (ORCPT ); Wed, 13 Feb 2019 17:42:27 -0500 Received: from mail-wm1-f68.google.com ([209.85.128.68]:55866 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2395185AbfBMWm0 (ORCPT ); Wed, 13 Feb 2019 17:42:26 -0500 Received: by mail-wm1-f68.google.com with SMTP id r17so4289340wmh.5; Wed, 13 Feb 2019 14:42:24 -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=FDryqu5ur4j9ePg/wc9MnpTPYVkBg8AjJFLLJs3gfA8=; b=NjIzVPkQI+bCcLNEI/Rt4U85tu0DGaKik0uQCOMXvSEkO/SvlHDTcAU8+IhLk21y1p 5m+FNp4iAWRrJ/k/DDDQZG8GEE1PO9QmTNuEZj9sZ3t8GOVxkaHS88LjJhq6BKQ7N9X3 FJu9x7w0j1lXKAVEa9NaOLOiDSwyj28NVgD1R/mi4Ij/muEfi9+4T/7X6PO8M08gwtT4 aaJwB93WJNH0Lk9jcLkQo1ju6chbGRcgdS0TIt45lL7EReQ2hPmGRvbjzBEH7IuKbkQK PTBJS9E+bupu40oKgPBcvq9VxB11GBhj6qIU7b2yqA1Ep6uVGLC5RY2njYXlBvxDI91M RhlQ== 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=FDryqu5ur4j9ePg/wc9MnpTPYVkBg8AjJFLLJs3gfA8=; b=Yw2hQ/LaP+YDXt+txVaKfoPEMJ6p0qbWRXy0sb37cujzMTxqRwgW8faKS2v5U3D05C LANJ9VfQF5v0veXGGP2a0f9P59HqFnhTB2frFGYnrAjUp2J811zamf4stPfD6kv1I5f+ OfJmgSiQ5hiJGJFT0VikTawmqxOD+k/lbo9/R/XVY7iovaPkmoyJRe+WYHMalPlZ2G+e UmxvzAb+myKT1uUjM+lcRR3LqAVUY19nyNPvFFfwetuPDtQQqJ5T2gjKIZrbBWWQtFYF s8x+Ug8+ve1CkXe9PN7dQzqmowH7G3rni8yHOq8YLFs/lFrEdrIjTI4q9EQ9F80q9SaQ /+Nw== X-Gm-Message-State: AHQUAuYBnglnpOhBmqubHsfK+8ZZJRXQSe9vqgpxQFF55WwCmbevm79z ixDqKw2ncZvcFIHs10+aDhE= X-Google-Smtp-Source: AHgI3Ia10COWxjNMWWeGUZ4kyfPoLmhHvf/GKRNqfO/0o20+P2q+df+RyfuyEETkMZNIJGOmGU8VSw== X-Received: by 2002:a1c:e086:: with SMTP id x128mr325384wmg.10.1550097743522; Wed, 13 Feb 2019 14:42:23 -0800 (PST) Received: from localhost.localdomain ([91.75.74.250]) by smtp.gmail.com with ESMTPSA id f196sm780810wme.36.2019.02.13.14.42.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 13 Feb 2019 14:42:22 -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 08/12] __wr_after_init: lkdtm test Date: Thu, 14 Feb 2019 00:41:37 +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 Verify that trying to modify a variable with the __wr_after_init attribute will cause a crash. 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 --- drivers/misc/lkdtm/core.c | 3 +++ drivers/misc/lkdtm/lkdtm.h | 3 +++ drivers/misc/lkdtm/perms.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 35 insertions(+) diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index 2837dc77478e..73c34b17c433 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -155,6 +155,9 @@ static const struct crashtype crashtypes[] = { CRASHTYPE(ACCESS_USERSPACE), CRASHTYPE(WRITE_RO), CRASHTYPE(WRITE_RO_AFTER_INIT), +#ifdef CONFIG_PRMEM + CRASHTYPE(WRITE_WR_AFTER_INIT), +#endif CRASHTYPE(WRITE_KERN), CRASHTYPE(REFCOUNT_INC_OVERFLOW), CRASHTYPE(REFCOUNT_ADD_OVERFLOW), diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index 3c6fd327e166..abba2f52ffa6 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -38,6 +38,9 @@ void lkdtm_READ_BUDDY_AFTER_FREE(void); void __init lkdtm_perms_init(void); void lkdtm_WRITE_RO(void); void lkdtm_WRITE_RO_AFTER_INIT(void); +#ifdef CONFIG_PRMEM +void lkdtm_WRITE_WR_AFTER_INIT(void); +#endif void lkdtm_WRITE_KERN(void); void lkdtm_EXEC_DATA(void); void lkdtm_EXEC_STACK(void); diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 53b85c9d16b8..f681730aa652 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -9,6 +9,7 @@ #include #include #include +#include #include /* Whether or not to fill the target memory area with do_nothing(). */ @@ -27,6 +28,10 @@ static const unsigned long rodata = 0xAA55AA55; /* This is marked __ro_after_init, so it should ultimately be .rodata. */ static unsigned long ro_after_init __ro_after_init = 0x55AA5500; +/* This is marked __wr_after_init, so it should be in .rodata. */ +static +unsigned long wr_after_init __wr_after_init = 0x55AA5500; + /* * This just returns to the caller. It is designed to be copied into * non-executable memory regions. @@ -104,6 +109,28 @@ void lkdtm_WRITE_RO_AFTER_INIT(void) *ptr ^= 0xabcd1234; } +#ifdef CONFIG_PRMEM + +void lkdtm_WRITE_WR_AFTER_INIT(void) +{ + unsigned long *ptr = &wr_after_init; + + /* + * Verify we were written to during init. Since an Oops + * is considered a "success", a failure is to just skip the + * real test. + */ + if ((*ptr & 0xAA) != 0xAA) { + pr_info("%p was NOT written during init!?\n", ptr); + return; + } + + pr_info("attempting bad wr_after_init write at %p\n", ptr); + *ptr ^= 0xabcd1234; +} + +#endif + void lkdtm_WRITE_KERN(void) { size_t size; @@ -200,4 +227,6 @@ void __init lkdtm_perms_init(void) /* Make sure we can write to __ro_after_init values during __init */ ro_after_init |= 0xAA; + /* Make sure we can write to __wr_after_init during __init */ + wr_after_init |= 0xAA; } -- 2.19.1