[v3,2/2] usb: core: Make default authorization mode configurable
Commit Message
From: Niko Mauno <niko.mauno@vaisala.com>
Make the default USB device authorization mode configurable at build
time. This is useful for systems that require a mode that is stricter
than the standard setting, as it avoids relying on the kernel command
line being properly set.
Signed-off-by: Niko Mauno <niko.mauno@vaisala.com>
---
drivers/usb/core/Kconfig | 28 ++++++++++++++++++++++++++++
drivers/usb/core/hcd.c | 2 +-
2 files changed, 29 insertions(+), 1 deletion(-)
@@ -116,3 +116,31 @@ config USB_AUTOSUSPEND_DELAY
The default value Linux has always had is 2 seconds. Change
this value if you want a different delay and cannot modify
the command line or module parameter.
+
+config USB_DEFAULT_AUTHORIZATION_MODE
+ int "Default authorization mode for USB devices"
+ range 0 2
+ default 1
+ depends on USB
+ help
+ Select the default USB device authorization mode. Can be overridden
+ with usbcore.authorized_default command line or module parameter.
+
+ This option allows you to choose whether USB devices that are
+ connected to the system can be used by default, or if they are
+ locked down.
+
+ With value 0 all connected USB devices with the exception of root
+ hub require user space authorization before they can be used.
+
+ With value 1 (default) no user space authorization is required to
+ use connected USB devices.
+
+ With value 2 all connected USB devices with exception of internal
+ USB devices require user space authorization before they can be
+ used. Note that in this mode the differentiation between internal
+ and external USB devices relies on ACPI, and on systems without
+ ACPI selecting value 2 is analogous to selecting value 0.
+
+ If the default value is too permissive but you are unsure which
+ mode to use, say 2.
@@ -357,7 +357,7 @@ static const u8 ss_rh_config_descriptor[] = {
#define USB_AUTHORIZE_ALL 1
#define USB_AUTHORIZE_INTERNAL 2
-static int authorized_default = USB_AUTHORIZE_ALL;
+static int authorized_default = CONFIG_USB_DEFAULT_AUTHORIZATION_MODE;
module_param(authorized_default, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(authorized_default,
"Default USB device authorization: 0 is not authorized, 1 is authorized (default), 2 is authorized for internal devices, -1 is authorized (same as 1)");