From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758618Ab3K0A6s (ORCPT ); Tue, 26 Nov 2013 19:58:48 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:39320 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932418Ab3K0A6g (ORCPT ); Tue, 26 Nov 2013 19:58:36 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook Subject: [PATCH 3.12 028/116] lkdtm: isolate stack corruption test Date: Tue, 26 Nov 2013 16:56:41 -0800 Message-Id: <20131127005738.887480864@linuxfoundation.org> X-Mailer: git-send-email 1.8.5.rc3 In-Reply-To: <20131127005736.915454872@linuxfoundation.org> References: <20131127005736.915454872@linuxfoundation.org> User-Agent: quilt/0.60-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook commit 629c66a22c21b692b6e58b9c1d8fa56a60ccb52d upstream. When tests were added to lkdtm that grew the stack frame, the stack corruption test stopped working. This isolates the test in its own function, and forces it not to be inlined. Signed-off-by: Kees Cook Fixes: cc33c537c12f ("lkdtm: add "EXEC_*" triggers") Signed-off-by: Greg Kroah-Hartman --- drivers/misc/lkdtm.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) --- a/drivers/misc/lkdtm.c +++ b/drivers/misc/lkdtm.c @@ -297,6 +297,14 @@ static void do_nothing(void) return; } +static noinline void corrupt_stack(void) +{ + /* Use default char array length that triggers stack protection. */ + char data[8]; + + memset((void *)data, 0, 64); +} + static void execute_location(void *dst) { void (*func)(void) = dst; @@ -327,13 +335,9 @@ static void lkdtm_do_action(enum ctype w case CT_OVERFLOW: (void) recursive_loop(0); break; - case CT_CORRUPT_STACK: { - /* Make sure the compiler creates and uses an 8 char array. */ - volatile char data[8]; - - memset((void *)data, 0, 64); + case CT_CORRUPT_STACK: + corrupt_stack(); break; - } case CT_UNALIGNED_LOAD_STORE_WRITE: { static u8 data[5] __attribute__((aligned(4))) = {1, 2, 3, 4, 5};