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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 29F9FC43381 for ; Sat, 30 Mar 2019 01:38:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDB77217F5 for ; Sat, 30 Mar 2019 01:38:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909911; bh=+oGEJGlWZ3n+aKt5lLM28Dlds+Sx0OaLv3xQF9+r2G0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ukvJNMY65inCjIwJDkhlq7roqoQQkNszkL9fOciR046smgTkqlwIkFSGIWIklbUWU CQDoIdnUGoTVDXFnmtUjHFcKSyjAqYhm/MApmxi+0RJXOxfHk4dvnOb8otlW342tNa Z/fi6VaesjBPuexzr7XIq11jAKxv5FIhay2Lt0mg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731698AbfC3BiY (ORCPT ); Fri, 29 Mar 2019 21:38:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:37492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731450AbfC3BaU (ORCPT ); Fri, 29 Mar 2019 21:30:20 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8041B218D8; Sat, 30 Mar 2019 01:30:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909419; bh=+oGEJGlWZ3n+aKt5lLM28Dlds+Sx0OaLv3xQF9+r2G0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DZriNhXSlYB0oLCtuq6l6XX4HAIWgXzrfGlyBK/XdH3BJljdDm/UZrDdfEf3LFcXp ufoPJ3bmeeS3VjVWV1vwUSmT51Rqavf9DVqTcCclnp2Y5nz4X7p2zFBFyI/hv6mKog V7ZDRsBdpHLyxPMOQwohiC75D+IxS0QKyyjpogKA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Christophe Leroy , Kees Cook , Sasha Levin Subject: [PATCH AUTOSEL 4.19 44/57] lkdtm: Add tests for NULL pointer dereference Date: Fri, 29 Mar 2019 21:28:37 -0400 Message-Id: <20190330012854.32212-44-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190330012854.32212-1-sashal@kernel.org> References: <20190330012854.32212-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 [ Upstream commit 59a12205d3c32aee4c13ca36889fdf7cfed31126 ] Introduce lkdtm tests for NULL pointer dereference: check access or exec at NULL address, since these errors tend to be reported differently from the general fault error text. For example from x86: pr_alert("BUG: unable to handle kernel %s at %px\n", address < PAGE_SIZE ? "NULL pointer dereference" : "paging request", (void *)address); Signed-off-by: Christophe Leroy Signed-off-by: Kees Cook Signed-off-by: Sasha Levin --- drivers/misc/lkdtm/core.c | 2 ++ drivers/misc/lkdtm/lkdtm.h | 2 ++ drivers/misc/lkdtm/perms.c | 18 ++++++++++++++++++ 3 files changed, 22 insertions(+) diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index 2154d1bfd18b..07caaa2cfe1e 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -152,7 +152,9 @@ static const struct crashtype crashtypes[] = { CRASHTYPE(EXEC_VMALLOC), CRASHTYPE(EXEC_RODATA), CRASHTYPE(EXEC_USERSPACE), + CRASHTYPE(EXEC_NULL), CRASHTYPE(ACCESS_USERSPACE), + CRASHTYPE(ACCESS_NULL), CRASHTYPE(WRITE_RO), CRASHTYPE(WRITE_RO_AFTER_INIT), CRASHTYPE(WRITE_KERN), diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index 9e513dcfd809..8c3f2e6af256 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -45,7 +45,9 @@ void lkdtm_EXEC_KMALLOC(void); void lkdtm_EXEC_VMALLOC(void); void lkdtm_EXEC_RODATA(void); void lkdtm_EXEC_USERSPACE(void); +void lkdtm_EXEC_NULL(void); void lkdtm_ACCESS_USERSPACE(void); +void lkdtm_ACCESS_NULL(void); /* lkdtm_refcount.c */ void lkdtm_REFCOUNT_INC_OVERFLOW(void); diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index fa54add6375a..62f76d506f04 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -164,6 +164,11 @@ void lkdtm_EXEC_USERSPACE(void) vm_munmap(user_addr, PAGE_SIZE); } +void lkdtm_EXEC_NULL(void) +{ + execute_location(NULL, CODE_AS_IS); +} + void lkdtm_ACCESS_USERSPACE(void) { unsigned long user_addr, tmp = 0; @@ -195,6 +200,19 @@ void lkdtm_ACCESS_USERSPACE(void) vm_munmap(user_addr, PAGE_SIZE); } +void lkdtm_ACCESS_NULL(void) +{ + unsigned long tmp; + unsigned long *ptr = (unsigned long *)NULL; + + pr_info("attempting bad read at %px\n", ptr); + tmp = *ptr; + tmp += 0xc0dec0de; + + pr_info("attempting bad write at %px\n", ptr); + *ptr = tmp; +} + void __init lkdtm_perms_init(void) { /* Make sure we can write to __ro_after_init values during __init */ -- 2.19.1