linux/drivers/hid/hid-cherry.c
Jiri Kosina 4ab25786c8 HID: fix a couple of off-by-ones
There are a few very theoretical off-by-one bugs in report descriptor size
checking when performing a pre-parsing fixup. Fix those.

Cc: stable@vger.kernel.org
Reported-by: Ben Hawkes <hawkes@google.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-21 10:43:28 -05:00

75 lines
2.0 KiB
C

/*
* HID driver for some cherry "special" devices
*
* Copyright (c) 1999 Andreas Gal
* Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
* Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
* Copyright (c) 2006-2007 Jiri Kosina
* Copyright (c) 2008 Jiri Slaby
*/
/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*/
#include <linux/device.h>
#include <linux/hid.h>
#include <linux/module.h>
#include "hid-ids.h"
/*
* Cherry Cymotion keyboard have an invalid HID report descriptor,
* that needs fixing before we can parse it.
*/
static __u8 *ch_report_fixup(struct hid_device *hdev, __u8 *rdesc,
unsigned int *rsize)
{
if (*rsize >= 18 && rdesc[11] == 0x3c && rdesc[12] == 0x02) {
hid_info(hdev, "fixing up Cherry Cymotion report descriptor\n");
rdesc[11] = rdesc[16] = 0xff;
rdesc[12] = rdesc[17] = 0x03;
}
return rdesc;
}
#define ch_map_key_clear(c) hid_map_usage_clear(hi, usage, bit, max, \
EV_KEY, (c))
static int ch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
struct hid_field *field, struct hid_usage *usage,
unsigned long **bit, int *max)
{
if ((usage->hid & HID_USAGE_PAGE) != HID_UP_CONSUMER)
return 0;
switch (usage->hid & HID_USAGE) {
case 0x301: ch_map_key_clear(KEY_PROG1); break;
case 0x302: ch_map_key_clear(KEY_PROG2); break;
case 0x303: ch_map_key_clear(KEY_PROG3); break;
default:
return 0;
}
return 1;
}
static const struct hid_device_id ch_devices[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_CHERRY, USB_DEVICE_ID_CHERRY_CYMOTION) },
{ HID_USB_DEVICE(USB_VENDOR_ID_CHERRY, USB_DEVICE_ID_CHERRY_CYMOTION_SOLAR) },
{ }
};
MODULE_DEVICE_TABLE(hid, ch_devices);
static struct hid_driver ch_driver = {
.name = "cherry",
.id_table = ch_devices,
.report_fixup = ch_report_fixup,
.input_mapping = ch_input_mapping,
};
module_hid_driver(ch_driver);
MODULE_LICENSE("GPL");