android_kernel_xiaomi_sm8350/drivers/hid/usbhid/usbhid.h
Alan Stern 613045bfc6 HID: usbhid: Fix race between usbhid_close() and usbhid_stop()
commit 0ed08faded1da03eb3def61502b27f81aef2e615 upstream.

The syzbot fuzzer discovered a bad race between in the usbhid driver
between usbhid_stop() and usbhid_close().  In particular,
usbhid_stop() does:

	usb_free_urb(usbhid->urbin);
	...
	usbhid->urbin = NULL; /* don't mess up next start */

and usbhid_close() does:

	usb_kill_urb(usbhid->urbin);

with no mutual exclusion.  If the two routines happen to run
concurrently so that usb_kill_urb() is called in between the
usb_free_urb() and the NULL assignment, it will access the
deallocated urb structure -- a use-after-free bug.

This patch adds a mutex to the usbhid private structure and uses it to
enforce mutual exclusion of the usbhid_start(), usbhid_stop(),
usbhid_open() and usbhid_close() callbacks.

Reported-and-tested-by: syzbot+7bf5a7b0f0a1f9446f4c@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-14 07:58:24 +02:00

98 lines
3.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef __USBHID_H
#define __USBHID_H
/*
* Copyright (c) 1999 Andreas Gal
* Copyright (c) 2000-2001 Vojtech Pavlik
* Copyright (c) 2006 Jiri Kosina
*/
/*
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/input.h>
/* API provided by hid-core.c for USB HID drivers */
void usbhid_init_reports(struct hid_device *hid);
struct usb_interface *usbhid_find_interface(int minor);
/* iofl flags */
#define HID_CTRL_RUNNING 1
#define HID_OUT_RUNNING 2
#define HID_IN_RUNNING 3
#define HID_RESET_PENDING 4
#define HID_SUSPENDED 5
#define HID_CLEAR_HALT 6
#define HID_DISCONNECTED 7
#define HID_STARTED 8
#define HID_KEYS_PRESSED 10
#define HID_NO_BANDWIDTH 11
#define HID_RESUME_RUNNING 12
/*
* The device is opened, meaning there is a client that is interested
* in data coming from the device.
*/
#define HID_OPENED 13
/*
* We are polling input endpoint by [re]submitting IN URB, because
* either HID device is opened or ALWAYS POLL quirk is set for the
* device.
*/
#define HID_IN_POLLING 14
/*
* USB-specific HID struct, to be pointed to
* from struct hid_device->driver_data
*/
struct usbhid_device {
struct hid_device *hid; /* pointer to corresponding HID dev */
struct usb_interface *intf; /* USB interface */
int ifnum; /* USB interface number */
unsigned int bufsize; /* URB buffer size */
struct urb *urbin; /* Input URB */
char *inbuf; /* Input buffer */
dma_addr_t inbuf_dma; /* Input buffer dma */
struct urb *urbctrl; /* Control URB */
struct usb_ctrlrequest *cr; /* Control request struct */
struct hid_control_fifo ctrl[HID_CONTROL_FIFO_SIZE]; /* Control fifo */
unsigned char ctrlhead, ctrltail; /* Control fifo head & tail */
char *ctrlbuf; /* Control buffer */
dma_addr_t ctrlbuf_dma; /* Control buffer dma */
unsigned long last_ctrl; /* record of last output for timeouts */
struct urb *urbout; /* Output URB */
struct hid_output_fifo out[HID_CONTROL_FIFO_SIZE]; /* Output pipe fifo */
unsigned char outhead, outtail; /* Output pipe fifo head & tail */
char *outbuf; /* Output buffer */
dma_addr_t outbuf_dma; /* Output buffer dma */
unsigned long last_out; /* record of last output for timeouts */
struct mutex mutex; /* start/stop/open/close */
spinlock_t lock; /* fifo spinlock */
unsigned long iofl; /* I/O flags (CTRL_RUNNING, OUT_RUNNING) */
struct timer_list io_retry; /* Retry timer */
unsigned long stop_retry; /* Time to give up, in jiffies */
unsigned int retry_delay; /* Delay length in ms */
struct work_struct reset_work; /* Task context for resets */
wait_queue_head_t wait; /* For sleeping */
};
#define hid_to_usb_dev(hid_dev) \
to_usb_device(hid_dev->dev.parent->parent)
#endif