From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752888AbbCMV4w (ORCPT ); Fri, 13 Mar 2015 17:56:52 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:32929 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751054AbbCMV4u (ORCPT ); Fri, 13 Mar 2015 17:56:50 -0400 From: Matthew Garrett To: linux-security-module@vger.kernel.org Cc: james.l.morris@oracle.com, serge@hallyn.com, linux-kernel@vger.kernel.org, keescook@chromium.org, hpa@zytor.com, gnomes@lxorguk.ukuu.org.uk, Matthew Garrett Date: Fri, 13 Mar 2015 11:38:27 -1000 Message-Id: <1426282708-21485-12-git-send-email-matthew.garrett@nebula.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1426282708-21485-1-git-send-email-matthew.garrett@nebula.com> References: <1426282708-21485-1-git-send-email-matthew.garrett@nebula.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 72.253.89.114 X-SA-Exim-Mail-From: matthew.garrett@nebula.com X-Spam-ASN: Subject: [PATCH 11/12] asus-wmi: Restrict debugfs interface when trusted_kernel is true X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:54:46 +0000) X-SA-Exim-Scanned: Yes (on cavan.codon.org.uk) 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 7543a56..d708fdc 100644 --- a/drivers/platform/x86/asus-wmi.c +++ b/drivers/platform/x86/asus-wmi.c @@ -47,6 +47,7 @@ #include #include #include +#include #include #include "asus-wmi.h" @@ -1589,6 +1590,9 @@ 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) @@ -1605,6 +1609,9 @@ 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); @@ -1629,6 +1636,9 @@ 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); -- 2.1.0