From patchwork Thu Jun 16 00:28:29 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 9180481 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 46AFA60760 for ; Thu, 16 Jun 2016 11:07:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3841E27DA4 for ; Thu, 16 Jun 2016 11:07:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2CB7C28308; Thu, 16 Jun 2016 11:07:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 7891227DA4 for ; Thu, 16 Jun 2016 11:07:37 +0000 (UTC) Received: (qmail 26464 invoked by uid 550); 16 Jun 2016 11:07:35 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Delivered-To: moderator for kernel-hardening@lists.openwall.com Received: (qmail 21950 invoked from network); 16 Jun 2016 00:29:04 -0000 From: Andy Lutomirski To: "linux-kernel@vger.kernel.org" , x86@kernel.org, Borislav Petkov Cc: Nadav Amit , Kees Cook , Brian Gerst , "kernel-hardening@lists.openwall.com" , Linus Torvalds , Josh Poimboeuf , Andy Lutomirski Date: Wed, 15 Jun 2016 17:28:29 -0700 Message-Id: <73fa53f32b34bd672d0f0e8f596f7982c71090d2.1466036668.git.luto@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP Subject: [kernel-hardening] [PATCH 07/13] x86/die: Don't try to recover from an OOPS on a non-default stack X-Virus-Scanned: ClamAV using ClamSMTP It's not going to work, because the scheduler will explode if we try to schedule when running on an IST stack or similar. This will matter when we let kernel stack overflows (which are #DF) call die(). Signed-off-by: Andy Lutomirski --- arch/x86/kernel/dumpstack.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index 2bb25c3fe2e8..36effb39c9c9 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -247,6 +247,9 @@ void oops_end(unsigned long flags, struct pt_regs *regs, int signr) return; if (in_interrupt()) panic("Fatal exception in interrupt"); + if (((current_stack_pointer() ^ (current_top_of_stack() - 1)) + & ~(THREAD_SIZE - 1)) != 0) + panic("Fatal exception on special stack"); if (panic_on_oops) panic("Fatal exception"); do_exit(signr);