From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 411B81A08D5 for ; Tue, 9 Sep 2014 05:25:46 +1000 (EST) From: Aaron Tomlin To: peterz@infradead.org Subject: [PATCH v2 0/3] sched: Always check the integrity of the canary Date: Mon, 8 Sep 2014 20:23:14 +0100 Message-Id: <1410204197-31204-1-git-send-email-atomlin@redhat.com> In-Reply-To: <20140904161124.GD1436@atomlin.usersys.redhat.com> References: <20140904161124.GD1436@atomlin.usersys.redhat.com> Cc: dzickus@redhat.com, jcastillo@redhat.com, riel@redhat.com, minchan@kernel.org, bmr@redhat.com, x86@kernel.org, oleg@redhat.com, rostedt@goodmis.org, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, mingo@redhat.com, aneesh.kumar@linux.vnet.ibm.com, akpm@google.com, atomlin@redhat.com, tglx@linutronix.de, linuxppc-dev@lists.ozlabs.org, akpm@linux-foundation.org, pzijlstr@redhat.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Currently in the event of a stack overrun a call to schedule() does not check for this type of corruption. This corruption is often silent and can go unnoticed. However once the corrupted region is examined at a later stage, the outcome is undefined and often results in a sporadic page fault which cannot be handled. The first patch adds a canary to init_task's end of stack. While the second patch provides a helper to determine the integrity of the canary. The third checks for a stack overrun and takes appropriate action since the damage is already done, there is no point in continuing. Changes since v1: * Rebased against v3.17-rc4 * Add a canary to init_task - Oleg Nesterov * Fix various code formatting issues - Peter Zijlstra * Introduce Kconfig option - Peter Zijlstra Aaron Tomlin (3): init/main.c: Give init_task a canary sched: Add helper for task stack page overrun checking sched: BUG when stack end location is over written arch/powerpc/mm/fault.c | 5 +---- arch/x86/mm/fault.c | 5 +---- include/linux/sched.h | 4 ++++ init/main.c | 1 + kernel/fork.c | 12 +++++++++--- kernel/sched/core.c | 4 ++++ kernel/trace/trace_stack.c | 4 +--- lib/Kconfig.debug | 12 ++++++++++++ 8 files changed, 33 insertions(+), 14 deletions(-) -- 1.9.3