Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754185AbdCFTKe (ORCPT ); Mon, 6 Mar 2017 14:10:34 -0500 Received: from mail-pf0-f177.google.com ([209.85.192.177]:36512 "EHLO mail-pf0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932496AbdCFTKL (ORCPT ); Mon, 6 Mar 2017 14:10:11 -0500 From: Kees Cook To: kernel-hardening@lists.openwall.com Cc: Kees Cook , Andrew Morton , Rik van Riel , "Paul E. McKenney" , Jakub Kicinski , Viresh Kumar , Ingo Molnar , Thomas Gleixner , Dmitry Vyukov , Olof Johansson , Peter Zijlstra , Josh Poimboeuf , linux-kernel@vger.kernel.org Subject: [PATCH 5/6] notifiers: Use CHECK_DATA_CORRUPTION() on checks Date: Mon, 6 Mar 2017 11:09:45 -0800 Message-Id: <1488827386-87193-6-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488827386-87193-1-git-send-email-keescook@chromium.org> References: <1488827386-87193-1-git-send-email-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1670 Lines: 50 When performing notifier function pointer sanity checking, allow CONFIG_BUG_ON_DATA_CORRUPTION to upgrade from a WARN to a BUG. Additionally enables CONFIG_DEBUG_NOTIFIERS when selecting CONFIG_BUG_ON_DATA_CORRUPTION. Signed-off-by: Kees Cook --- kernel/notifier.c | 5 +++-- lib/Kconfig.debug | 3 ++- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/notifier.c b/kernel/notifier.c index 6196af8a8223..58cc14958d92 100644 --- a/kernel/notifier.c +++ b/kernel/notifier.c @@ -84,8 +84,9 @@ static int notifier_call_chain(struct notifier_block **nl, next_nb = rcu_dereference_raw(nb->next); #ifdef CONFIG_DEBUG_NOTIFIERS - if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) { - WARN(1, "Invalid notifier called!"); + if (CHECK_DATA_CORRUPTION( + !func_ptr_is_kernel_text(nb->notifier_call), + "Invalid notifier called!")) { nb = next_nb; continue; } diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 42c61cfe7d19..70e9f2c1bb30 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1277,7 +1277,7 @@ config DEBUG_SG config DEBUG_NOTIFIERS bool "Debug notifier call chains" - depends on DEBUG_KERNEL + depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION help Enable this to turn on sanity checking for notifier call chains. This is most useful for kernel developers to make sure that @@ -1995,6 +1995,7 @@ config BUG_ON_DATA_CORRUPTION bool "Trigger a BUG when data corruption is detected" select DEBUG_CREDENTIALS select DEBUG_LIST + select DEBUG_NOTIFIERS select DEBUG_SG help This option enables several inexpensive data corruption checks. -- 2.7.4