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linux-next/drivers/hid/hid-zpff.c
Alan Stern d9d4b1e46d HID: Fix assumption that devices have inputs
The syzbot fuzzer found a slab-out-of-bounds write bug in the hid-gaff
driver.  The problem is caused by the driver's assumption that the
device must have an input report.  While this will be true for all
normal HID input devices, a suitably malicious device can violate the
assumption.

The same assumption is present in over a dozen other HID drivers.
This patch fixes them by checking that the list of hid_inputs for the
hid_device is nonempty before allowing it to be used.

Reported-and-tested-by: syzbot+403741a091bf41d4ae79@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
2019-10-03 15:36:40 -04:00

142 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Force feedback support for Zeroplus based devices
*
* Copyright (c) 2005, 2006 Anssi Hannula <anssi.hannula@gmail.com>
*/
/*
*/
#include <linux/hid.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/module.h>
#include "hid-ids.h"
#ifdef CONFIG_ZEROPLUS_FF
struct zpff_device {
struct hid_report *report;
};
static int zpff_play(struct input_dev *dev, void *data,
struct ff_effect *effect)
{
struct hid_device *hid = input_get_drvdata(dev);
struct zpff_device *zpff = data;
int left, right;
/*
* The following is specified the other way around in the Zeroplus
* datasheet but the order below is correct for the XFX Executioner;
* however it is possible that the XFX Executioner is an exception
*/
left = effect->u.rumble.strong_magnitude;
right = effect->u.rumble.weak_magnitude;
dbg_hid("called with 0x%04x 0x%04x\n", left, right);
left = left * 0x7f / 0xffff;
right = right * 0x7f / 0xffff;
zpff->report->field[2]->value[0] = left;
zpff->report->field[3]->value[0] = right;
dbg_hid("running with 0x%02x 0x%02x\n", left, right);
hid_hw_request(hid, zpff->report, HID_REQ_SET_REPORT);
return 0;
}
static int zpff_init(struct hid_device *hid)
{
struct zpff_device *zpff;
struct hid_report *report;
struct hid_input *hidinput;
struct input_dev *dev;
int i, error;
if (list_empty(&hid->inputs)) {
hid_err(hid, "no inputs found\n");
return -ENODEV;
}
hidinput = list_entry(hid->inputs.next, struct hid_input, list);
dev = hidinput->input;
for (i = 0; i < 4; i++) {
report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, i, 1);
if (!report)
return -ENODEV;
}
zpff = kzalloc(sizeof(struct zpff_device), GFP_KERNEL);
if (!zpff)
return -ENOMEM;
set_bit(FF_RUMBLE, dev->ffbit);
error = input_ff_create_memless(dev, zpff, zpff_play);
if (error) {
kfree(zpff);
return error;
}
zpff->report = report;
zpff->report->field[0]->value[0] = 0x00;
zpff->report->field[1]->value[0] = 0x02;
zpff->report->field[2]->value[0] = 0x00;
zpff->report->field[3]->value[0] = 0x00;
hid_hw_request(hid, zpff->report, HID_REQ_SET_REPORT);
hid_info(hid, "force feedback for Zeroplus based devices by Anssi Hannula <anssi.hannula@gmail.com>\n");
return 0;
}
#else
static inline int zpff_init(struct hid_device *hid)
{
return 0;
}
#endif
static int zp_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
int ret;
ret = hid_parse(hdev);
if (ret) {
hid_err(hdev, "parse failed\n");
goto err;
}
ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
if (ret) {
hid_err(hdev, "hw start failed\n");
goto err;
}
zpff_init(hdev);
return 0;
err:
return ret;
}
static const struct hid_device_id zp_devices[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_ZEROPLUS, 0x0005) },
{ HID_USB_DEVICE(USB_VENDOR_ID_ZEROPLUS, 0x0030) },
{ }
};
MODULE_DEVICE_TABLE(hid, zp_devices);
static struct hid_driver zp_driver = {
.name = "zeroplus",
.id_table = zp_devices,
.probe = zp_probe,
};
module_hid_driver(zp_driver);
MODULE_LICENSE("GPL");