From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35862 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933800AbdERNSg (ORCPT ); Thu, 18 May 2017 09:18:36 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jann Horn , Linus Torvalds , Amit Pundir Subject: [PATCH 3.18 44/49] sched: panic on corrupted stack end Date: Thu, 18 May 2017 15:16:53 +0200 Message-Id: <20170518131644.900831583@linuxfoundation.org> In-Reply-To: <20170518131643.028057293@linuxfoundation.org> References: <20170518131643.028057293@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jann Horn commit 29d6455178a09e1dc340380c582b13356227e8df upstream. Until now, hitting this BUG_ON caused a recursive oops (because oops handling involves do_exit(), which calls into the scheduler, which in turn raises an oops), which caused stuff below the stack to be overwritten until a panic happened (e.g. via an oops in interrupt context, caused by the overwritten CPU index in the thread_info). Just panic directly. Signed-off-by: Jann Horn Signed-off-by: Linus Torvalds [AmitP: Minor refactoring of upstream changes for linux-3.18.y] Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- kernel/sched/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2709,7 +2709,8 @@ static noinline void __schedule_bug(stru static inline void schedule_debug(struct task_struct *prev) { #ifdef CONFIG_SCHED_STACK_END_CHECK - BUG_ON(unlikely(task_stack_end_corrupted(prev))); + if (task_stack_end_corrupted(prev)) + panic("corrupted stack end detected inside scheduler\n"); #endif /* * Test if we are atomic. Since do_exit() needs to call into