Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751205Ab3HSQRp (ORCPT ); Mon, 19 Aug 2013 12:17:45 -0400 Received: from cavan.codon.org.uk ([93.93.128.6]:49981 "EHLO cavan.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751178Ab3HSQLK (ORCPT ); Mon, 19 Aug 2013 12:11:10 -0400 From: Matthew Garrett To: linux-kernel@vger.kernel.org Cc: linux-efi@vger.kernel.org, jwboyer@redhat.com, keescook@chromium.org, Matthew Garrett Subject: [PATCH 05/10] asus-wmi: Restrict debugfs interface when module loading is restricted Date: Mon, 19 Aug 2013 12:10:14 -0400 Message-Id: <1376928619-3775-5-git-send-email-matthew.garrett@nebula.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1376928619-3775-1-git-send-email-matthew.garrett@nebula.com> References: <1376928619-3775-1-git-send-email-matthew.garrett@nebula.com> X-SA-Do-Not-Run: Yes X-SA-Exim-Connect-IP: 2001:470:1f07:1371:6267:20ff:fec3:2318 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 Content-Length: 1700 Lines: 53 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, circumventing module loading restrictions. Prevent that if any of these features are enabled. 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 19c313b..8105530 100644 --- a/drivers/platform/x86/asus-wmi.c +++ b/drivers/platform/x86/asus-wmi.c @@ -1618,6 +1618,9 @@ static int show_dsts(struct seq_file *m, void *data) int err; u32 retval = -1; + if (secure_modules()) + return -EPERM; + err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval); if (err < 0) @@ -1634,6 +1637,9 @@ 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); @@ -1658,6 +1664,9 @@ 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); -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/