From patchwork Sun Jun 26 21:55:32 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Lutomirski X-Patchwork-Id: 9199657 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 07CFF60752 for ; Sun, 26 Jun 2016 21:57:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EE98C28521 for ; Sun, 26 Jun 2016 21:57:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E2B5E2855A; Sun, 26 Jun 2016 21:57:38 +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 3251A28521 for ; Sun, 26 Jun 2016 21:57:38 +0000 (UTC) Received: (qmail 32472 invoked by uid 550); 26 Jun 2016 21:56:27 -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 Received: (qmail 32359 invoked from network); 26 Jun 2016 21:56:24 -0000 From: Andy Lutomirski To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Borislav Petkov , Nadav Amit , Kees Cook , Brian Gerst , "kernel-hardening@lists.openwall.com" , Linus Torvalds , Josh Poimboeuf , Jann Horn , Heiko Carstens , Andy Lutomirski Date: Sun, 26 Jun 2016 14:55:32 -0700 Message-Id: <37ac7589ff0ea147e8a21cda5eb84d3af1f6cd60.1466974736.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 v4 10/29] 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 ef8017ca5ba9..352f022cfd5b 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -245,6 +245,9 @@ 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);