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-rw-r--r--include/linux/hid.h42
1 files changed, 29 insertions, 13 deletions
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 875f71132b14..c7044a14200e 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -959,34 +959,49 @@ static inline void hid_device_io_stop(struct hid_device *hid) {
* @max: maximal valid usage->code to consider later (out parameter)
* @type: input event type (EV_KEY, EV_REL, ...)
* @c: code which corresponds to this usage and type
+ *
+ * The value pointed to by @bit will be set to NULL if either @type is
+ * an unhandled event type, or if @c is out of range for @type. This
+ * can be used as an error condition.
*/
static inline void hid_map_usage(struct hid_input *hidinput,
struct hid_usage *usage, unsigned long **bit, int *max,
- __u8 type, __u16 c)
+ __u8 type, unsigned int c)
{
struct input_dev *input = hidinput->input;
-
- usage->type = type;
- usage->code = c;
+ unsigned long *bmap = NULL;
+ unsigned int limit = 0;
switch (type) {
case EV_ABS:
- *bit = input->absbit;
- *max = ABS_MAX;
+ bmap = input->absbit;
+ limit = ABS_MAX;
break;
case EV_REL:
- *bit = input->relbit;
- *max = REL_MAX;
+ bmap = input->relbit;
+ limit = REL_MAX;
break;
case EV_KEY:
- *bit = input->keybit;
- *max = KEY_MAX;
+ bmap = input->keybit;
+ limit = KEY_MAX;
break;
case EV_LED:
- *bit = input->ledbit;
- *max = LED_MAX;
+ bmap = input->ledbit;
+ limit = LED_MAX;
break;
}
+
+ if (unlikely(c > limit || !bmap)) {
+ pr_warn_ratelimited("%s: Invalid code %d type %d\n",
+ input->name, c, type);
+ *bit = NULL;
+ return;
+ }
+
+ usage->type = type;
+ usage->code = c;
+ *max = limit;
+ *bit = bmap;
}
/**
@@ -1000,7 +1015,8 @@ static inline void hid_map_usage_clear(struct hid_input *hidinput,
__u8 type, __u16 c)
{
hid_map_usage(hidinput, usage, bit, max, type, c);
- clear_bit(c, *bit);
+ if (*bit)
+ clear_bit(usage->code, *bit);
}
/**