From patchwork Mon Mar 18 21:32:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 228813 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3D84D2C00AE for ; Tue, 19 Mar 2013 08:34:21 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932861Ab3CRVeA (ORCPT ); Mon, 18 Mar 2013 17:34:00 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:35945 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933344Ab3CRVc7 (ORCPT ); Mon, 18 Mar 2013 17:32:59 -0400 Received: from [2001:470:1f07:1371:e0f4:3a1:9c35:d688] (helo=x230.mview.int.nebula.com) by cavan.codon.org.uk with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1UHhfu-0006Ez-9F; Mon, 18 Mar 2013 21:32:58 +0000 From: Matthew Garrett To: linux-kernel@vger.kernel.org Cc: linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, Matthew Garrett Subject: [PATCH 08/12] asus-wmi: Restrict debugfs interface Date: Mon, 18 Mar 2013 17:32:29 -0400 Message-Id: <1363642353-30749-8-git-send-email-matthew.garrett@nebula.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1363642353-30749-1-git-send-email-matthew.garrett@nebula.com> References: <1363642353-30749-1-git-send-email-matthew.garrett@nebula.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 2001:470:1f07:1371:e0f4:3a1:9c35:d688 X-SA-Exim-Mail-From: matthew.garrett@nebula.com X-SA-Exim-Scanned: No (on cavan.codon.org.uk); SAEximRunCond expanded to false Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org We have no way of validating what all of the Asus WMI methods do on a given machine, and there's a risk that some will allow hardware state to be manipulated in such a way that arbitrary code can be executed in the kernel. Add a capability check to prevent that. Signed-off-by: Matthew Garrett --- drivers/platform/x86/asus-wmi.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c index c11b242..6d5f88f 100644 --- a/drivers/platform/x86/asus-wmi.c +++ b/drivers/platform/x86/asus-wmi.c @@ -1617,6 +1617,9 @@ static int show_dsts(struct seq_file *m, void *data) int err; u32 retval = -1; + if (!capable(CAP_COMPROMISE_KERNEL)) + return -EPERM; + err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval); if (err < 0) @@ -1633,6 +1636,9 @@ static int show_devs(struct seq_file *m, void *data) int err; u32 retval = -1; + if (!capable(CAP_COMPROMISE_KERNEL)) + return -EPERM; + err = asus_wmi_set_devstate(asus->debug.dev_id, asus->debug.ctrl_param, &retval); @@ -1657,6 +1663,9 @@ static int show_call(struct seq_file *m, void *data) union acpi_object *obj; acpi_status status; + if (!capable(CAP_COMPROMISE_KERNEL)) + return -EPERM; + status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID, 1, asus->debug.method_id, &input, &output);