From: Matthew Garrett Date: Wed, 8 Nov 2017 15:11:34 +0000 (+0000) Subject: asus-wmi: Restrict debugfs interface when the kernel is locked down X-Git-Tag: archive/raspbian/4.18.20-2+rpi1^2~36 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=094673a6c223a054377c789175899ac8039d41cb;p=linux.git asus-wmi: Restrict debugfs interface when the kernel is locked down 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 Signed-off-by: David Howells Reviewed-by: "Lee, Chun-Yi" cc: acpi4asus-user@lists.sourceforge.net cc: platform-driver-x86@vger.kernel.org Gbp-Pq: Topic features/all/lockdown Gbp-Pq: Name 0014-asus-wmi-Restrict-debugfs-interface-when-the-kernel-.patch --- diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c index 3d523ca6469..2ccafec9f9c 100644 --- a/drivers/platform/x86/asus-wmi.c +++ b/drivers/platform/x86/asus-wmi.c @@ -1980,6 +1980,9 @@ static int show_dsts(struct seq_file *m, void *data) int err; u32 retval = -1; + if (kernel_is_locked_down("Asus WMI")) + return -EPERM; + err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval); if (err < 0) @@ -1996,6 +1999,9 @@ static int show_devs(struct seq_file *m, void *data) int err; u32 retval = -1; + if (kernel_is_locked_down("Asus WMI")) + return -EPERM; + err = asus_wmi_set_devstate(asus->debug.dev_id, asus->debug.ctrl_param, &retval); @@ -2020,6 +2026,9 @@ static int show_call(struct seq_file *m, void *data) union acpi_object *obj; acpi_status status; + if (kernel_is_locked_down("Asus WMI")) + return -EPERM; + status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID, 0, asus->debug.method_id, &input, &output);