From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754201AbaBZUQb (ORCPT ); Wed, 26 Feb 2014 15:16:31 -0500 Received: from cavan.codon.org.uk ([93.93.128.6]:44226 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753930AbaBZUQ3 (ORCPT ); Wed, 26 Feb 2014 15:16:29 -0500 From: Matthew Garrett To: linux-kernel@vger.kernel.org Cc: keescook@chromium.org, gregkh@linuxfoundation.org, hpa@zytor.com, linux-efi@vger.kernel.org, jmorris@namei.org, linux-security-module@vger.kernel.org, Matthew Garrett Subject: [PATCH 11/12] asus-wmi: Restrict debugfs interface when trusted_kernel is true Date: Wed, 26 Feb 2014 15:11:12 -0500 Message-Id: <1393445473-15068-12-git-send-email-matthew.garrett@nebula.com> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1393445473-15068-1-git-send-email-matthew.garrett@nebula.com> References: <1393445473-15068-1-git-send-email-matthew.garrett@nebula.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 209.6.207.143 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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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. Prevent that if trusted_kernel is true. Signed-off-by: Matthew Garrett --- drivers/platform/x86/asus-wmi.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c index c5e082f..4c1000b 100644 --- a/drivers/platform/x86/asus-wmi.c +++ b/drivers/platform/x86/asus-wmi.c @@ -46,6 +46,7 @@ #include #include #include +#include #include #include "asus-wmi.h" @@ -1595,6 +1596,9 @@ static int show_dsts(struct seq_file *m, void *data) int err; u32 retval = -1; + if (get_trusted_kernel()) + return -EPERM; + err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval); if (err < 0) @@ -1611,6 +1615,9 @@ static int show_devs(struct seq_file *m, void *data) int err; u32 retval = -1; + if (get_trusted_kernel()) + return -EPERM; + err = asus_wmi_set_devstate(asus->debug.dev_id, asus->debug.ctrl_param, &retval); @@ -1635,6 +1642,9 @@ static int show_call(struct seq_file *m, void *data) union acpi_object *obj; acpi_status status; + if (get_trusted_kernel()) + return -EPERM; + status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID, 1, asus->debug.method_id, &input, &output); -- 1.8.5.3