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 04A28C4360F for ; Sat, 30 Mar 2019 01:35:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9312217F5 for ; Sat, 30 Mar 2019 01:35:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909713; bh=h59oNUj2ZgAJrh7bWqOspb/P244TvCd298Eq9lf726g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sMwP9bJr3s0YWhUeZ67Gpph/0YuNccJ4xEO0S5DbZNSL82hrgLYSddfDMNkcbE6rk eg+ex8fyJFGGsB90GcINmuUrKAYFZw9OaAIv83JmVlBvGkgseJpt3Q0DQ8fRmt1Oj/ AIeMUdTKtGvsw9Gu4eEgzFZJ2UEhSYgYqSYAERtk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731402AbfC3BfN (ORCPT ); Fri, 29 Mar 2019 21:35:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:39604 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731261AbfC3Bbs (ORCPT ); Fri, 29 Mar 2019 21:31:48 -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 138B32184C; Sat, 30 Mar 2019 01:31:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553909507; bh=h59oNUj2ZgAJrh7bWqOspb/P244TvCd298Eq9lf726g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=s62er4sOerGuEbfYY0q6uF35GT3WuZGrJCbt9gLBg8S2JPLvYaqjKVcRgzXtpGOnR v7xy5nFi338Nsf0f1sqPjxUT2wypGMJdHSLERpD0V82t7UU9N/QsgnSsbZSa+V8ILj 2zBsieMoSjldpEzK5Cp8wtoCPHyuoO0PeoUe1rf4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Christophe Leroy , Kees Cook , Sasha Levin Subject: [PATCH AUTOSEL 4.9 17/21] lkdtm: Add tests for NULL pointer dereference Date: Fri, 29 Mar 2019 21:31:08 -0400 Message-Id: <20190330013112.784-17-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190330013112.784-1-sashal@kernel.org> References: <20190330013112.784-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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.h | 2 ++ drivers/misc/lkdtm_core.c | 2 ++ drivers/misc/lkdtm_perms.c | 18 ++++++++++++++++++ 3 files changed, 22 insertions(+) diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h index fdf954c2107f..6abc97b245e4 100644 --- a/drivers/misc/lkdtm.h +++ b/drivers/misc/lkdtm.h @@ -40,7 +40,9 @@ 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_rodata.c */ void lkdtm_rodata_do_nothing(void); diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c index b2989f2d3126..035e51bea450 100644 --- a/drivers/misc/lkdtm_core.c +++ b/drivers/misc/lkdtm_core.c @@ -214,7 +214,9 @@ 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_perms.c b/drivers/misc/lkdtm_perms.c index 45f1c0f96612..1a9dcdaa95f0 100644 --- a/drivers/misc/lkdtm_perms.c +++ b/drivers/misc/lkdtm_perms.c @@ -160,6 +160,11 @@ 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; @@ -191,6 +196,19 @@ 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