Commit e1443d28 authored by Stephen Chandler Paul's avatar Stephen Chandler Paul Committed by Dmitry Torokhov
Browse files

Input: i8042 - add unmask_kbd_data option 



A big problem with the current i8042 debugging option is that it outputs
data going to and from the keyboard by default. As a result, many dmesg
logs uploaded by users will unintentionally contain sensitive information
such as their password, as such it's probably a good idea not to output
data coming from the keyboard unless specifically enabled by the user.

Signed-off-by: default avatarStephen Chandler Paul <cpaul@redhat.com>
Reviewed-by: default avatarAndreas Mohr <andim2@users.sf.net>
Reviewed-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 339d6b88

Documentation/kernel-parameters.txt

+4 −0
Original line number Diff line number Diff line
@@ -1274,6 +1274,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			     <bus_id>,<clkrate>



	i8042.debug	[HW] Toggle i8042 debug mode

	i8042.unmask_kbd_data

			[HW] Enable printing of interrupt data from the KBD port

			     (disabled by default, and as a pre-condition

			     requires that i8042.debug=1 be enabled)

	i8042.direct	[HW] Put keyboard port into non-translated mode

	i8042.dumbkbd	[HW] Pretend that controller can only read data from

			     keyboard and cannot control its state

drivers/input/serio/i8042.c

+39 −4
Original line number Diff line number Diff line
@@ -88,6 +88,10 @@ MODULE_PARM_DESC(nopnp, "Do not use PNP to detect controller settings"); 
static bool i8042_debug;

module_param_named(debug, i8042_debug, bool, 0600);

MODULE_PARM_DESC(debug, "Turn i8042 debugging mode on and off");



static bool i8042_unmask_kbd_data;

module_param_named(unmask_kbd_data, i8042_unmask_kbd_data, bool, 0600);

MODULE_PARM_DESC(unmask_kbd_data, "Unconditional enable (may reveal sensitive data) of normally sanitize-filtered kbd data traffic debug log [pre-condition: i8042.debug=1 enabled]");

#endif



static bool i8042_bypass_aux_irq_test;
@@ -116,6 +120,7 @@ struct i8042_port { 
	struct serio *serio;

	int irq;

	bool exists;

	bool driver_bound;

	signed char mux;

};
@@ -133,6 +138,7 @@ static bool i8042_kbd_irq_registered; 
static bool i8042_aux_irq_registered;

static unsigned char i8042_suppress_kbd_ack;

static struct platform_device *i8042_platform_device;

static struct notifier_block i8042_kbd_bind_notifier_block;



static irqreturn_t i8042_interrupt(int irq, void *dev_id);

static bool (*i8042_platform_filter)(unsigned char data, unsigned char str,
@@ -528,8 +534,8 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id) 
	port = &i8042_ports[port_no];

	serio = port->exists ? port->serio : NULL;



	dbg("%02x <- i8042 (interrupt, %d, %d%s%s)\n",

	    data, port_no, irq,

	filter_dbg(port->driver_bound, data, "<- i8042 (interrupt, %d, %d%s%s)\n",

		   port_no, irq,

		   dfl & SERIO_PARITY ? ", bad parity" : "",

		   dfl & SERIO_TIMEOUT ? ", timeout" : "");
@@ -1438,6 +1444,29 @@ static int __init i8042_setup_kbd(void) 
	return error;

}



static int i8042_kbd_bind_notifier(struct notifier_block *nb,

				   unsigned long action, void *data)

{

	struct device *dev = data;

	struct serio *serio = to_serio_port(dev);

	struct i8042_port *port = serio->port_data;



	if (serio != i8042_ports[I8042_KBD_PORT_NO].serio)

		return 0;



	switch (action) {

	case BUS_NOTIFY_BOUND_DRIVER:

		port->driver_bound = true;

		break;



	case BUS_NOTIFY_UNBIND_DRIVER:

		port->driver_bound = false;

		break;

	}



	return 0;

}



static int __init i8042_probe(struct platform_device *dev)

{

	int error;
@@ -1507,6 +1536,10 @@ static struct platform_driver i8042_driver = { 
	.shutdown	= i8042_shutdown,

};



static struct notifier_block i8042_kbd_bind_notifier_block = {

	.notifier_call = i8042_kbd_bind_notifier,

};



static int __init i8042_init(void)

{

	struct platform_device *pdev;
@@ -1528,6 +1561,7 @@ static int __init i8042_init(void) 
		goto err_platform_exit;

	}



	bus_register_notifier(&serio_bus, &i8042_kbd_bind_notifier_block);

	panic_blink = i8042_panic_blink;



	return 0;
@@ -1543,6 +1577,7 @@ static void __exit i8042_exit(void) 
	platform_driver_unregister(&i8042_driver);

	i8042_platform_exit();



	bus_unregister_notifier(&serio_bus, &i8042_kbd_bind_notifier_block);

	panic_blink = NULL;

}

drivers/input/serio/i8042.h

+13 −0
Original line number Diff line number Diff line
@@ -73,6 +73,17 @@ static unsigned long i8042_start_time; 
			printk(KERN_DEBUG KBUILD_MODNAME ": [%d] " format,	\

			       (int) (jiffies - i8042_start_time), ##arg);	\

	} while (0)



#define filter_dbg(filter, data, format, args...)		\

	do {							\

		if (!i8042_debug)				\

			break;					\

								\

		if (!filter || i8042_unmask_kbd_data)		\

			dbg("%02x " format, data, ##args);	\

		else						\

			dbg("** " format, ##args);		\

	} while (0)

#else

#define dbg_init() do { } while (0)

#define dbg(format, arg...)							\
@@ -80,6 +91,8 @@ static unsigned long i8042_start_time; 
		if (0)								\

			printk(KERN_DEBUG pr_fmt(format), ##arg);		\

	} while (0)



#define filter_dbg(filter, data, format, args...) do { } while (0)

#endif



#endif /* _I8042_H */

drivers/input/serio/serio.c

+2 −3
Original line number Diff line number Diff line
@@ -49,8 +49,6 @@ static DEFINE_MUTEX(serio_mutex); 


static LIST_HEAD(serio_list);



static struct bus_type serio_bus;



static void serio_add_port(struct serio *serio);

static int serio_reconnect_port(struct serio *serio);

static void serio_disconnect_port(struct serio *serio);
@@ -1017,7 +1015,7 @@ irqreturn_t serio_interrupt(struct serio *serio, 
}

EXPORT_SYMBOL(serio_interrupt);



static struct bus_type serio_bus = {

struct bus_type serio_bus = {

	.name		= "serio",

	.drv_groups	= serio_driver_groups,

	.match		= serio_bus_match,
@@ -1029,6 +1027,7 @@ static struct bus_type serio_bus = { 
	.pm		= &serio_pm_ops,

#endif

};

EXPORT_SYMBOL(serio_bus);



static int __init serio_init(void)

{

include/linux/serio.h

+2 −0
Original line number Diff line number Diff line
@@ -18,6 +18,8 @@ 
#include <linux/mod_devicetable.h>

#include <uapi/linux/serio.h>



extern struct bus_type serio_bus;



struct serio {

	void *port_data;