From e1443d2849b146be4ed8d4ef89ae7e215aafaa5b Mon Sep 17 00:00:00 2001 From: Stephen Chandler Paul Date: Wed, 15 Jul 2015 10:20:17 -0700 Subject: [PATCH] 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: Stephen Chandler Paul Reviewed-by: Andreas Mohr Reviewed-by: Benjamin Tissoires Signed-off-by: Dmitry Torokhov --- Documentation/kernel-parameters.txt | 4 +++ drivers/input/serio/i8042.c | 43 ++++++++++++++++++++++++++--- drivers/input/serio/i8042.h | 13 +++++++++ drivers/input/serio/serio.c | 5 ++-- include/linux/serio.h | 2 ++ 5 files changed, 60 insertions(+), 7 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index bfcb1a62a7b4..fd0f7cd8e496 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1274,6 +1274,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. , 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 diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index cb5ece77fd7d..c9c98f0ab284 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -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, @@ -528,10 +534,10 @@ 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, - dfl & SERIO_PARITY ? ", bad parity" : "", - dfl & SERIO_TIMEOUT ? ", timeout" : ""); + 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" : ""); filtered = i8042_filter(data, str, serio); @@ -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; } diff --git a/drivers/input/serio/i8042.h b/drivers/input/serio/i8042.h index fc080beffedc..1db0a40c9bab 100644 --- a/drivers/input/serio/i8042.h +++ b/drivers/input/serio/i8042.h @@ -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 */ diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c index a05a5179da32..8f828975ab10 100644 --- a/drivers/input/serio/serio.c +++ b/drivers/input/serio/serio.c @@ -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) { diff --git a/include/linux/serio.h b/include/linux/serio.h index 9f779c7a2da4..df4ab5de1586 100644 --- a/include/linux/serio.h +++ b/include/linux/serio.h @@ -18,6 +18,8 @@ #include #include +extern struct bus_type serio_bus; + struct serio { void *port_data; -- 2.20.1