From bfa10bc7193d6309dc8029e18fe7d844f9a3a1c0 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <matthew.garrett@nebula.com>
Date: Wed, 5 Apr 2017 17:40:30 +0100
Subject: [PATCH 53/62] asus-wmi: Restrict debugfs interface when the kernel is
locked down
Patch-mainline: No, submitted
References: fate#314486
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 the
kernel is locked down.
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
drivers/platform/x86/asus-wmi.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -1905,6 +1905,9 @@ static int show_dsts(struct seq_file *m,
int err;
u32 retval = -1;
+ if (kernel_is_locked_down())
+ return -EPERM;
+
err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval);
if (err < 0)
@@ -1921,6 +1924,9 @@ static int show_devs(struct seq_file *m,
int err;
u32 retval = -1;
+ if (kernel_is_locked_down())
+ return -EPERM;
+
err = asus_wmi_set_devstate(asus->debug.dev_id, asus->debug.ctrl_param,
&retval);
@@ -1945,6 +1951,9 @@ static int show_call(struct seq_file *m,
union acpi_object *obj;
acpi_status status;
+ if (kernel_is_locked_down())
+ return -EPERM;
+
status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID,
1, asus->debug.method_id,
&input, &output);