alistair23-linux/include/linux/hid-debug.h
Vladis Dronov 13054abbaa HID: debug: fix the ring buffer implementation
Ring buffer implementation in hid_debug_event() and hid_debug_events_read()
is strange allowing lost or corrupted data. After commit 717adfdaf1
("HID: debug: check length before copy_to_user()") it is possible to enter
an infinite loop in hid_debug_events_read() by providing 0 as count, this
locks up a system. Fix this by rewriting the ring buffer implementation
with kfifo and simplify the code.

This fixes CVE-2019-3819.

v2: fix an execution logic and add a comment
v3: use __set_current_state() instead of set_current_state()

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1669187
Cc: stable@vger.kernel.org # v4.18+
Fixes: cd667ce247 ("HID: use debugfs for events/reports dumping")
Fixes: 717adfdaf1 ("HID: debug: check length before copy_to_user()")
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
2019-01-29 12:09:11 +01:00

67 lines
2.1 KiB
C

#ifndef __HID_DEBUG_H
#define __HID_DEBUG_H
/*
* Copyright (c) 2007-2009 Jiri Kosina
*/
/*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifdef CONFIG_DEBUG_FS
#include <linux/kfifo.h>
#define HID_DEBUG_BUFSIZE 512
#define HID_DEBUG_FIFOSIZE 512
void hid_dump_input(struct hid_device *, struct hid_usage *, __s32);
void hid_dump_report(struct hid_device *, int , u8 *, int);
void hid_dump_device(struct hid_device *, struct seq_file *);
void hid_dump_field(struct hid_field *, int, struct seq_file *);
char *hid_resolv_usage(unsigned, struct seq_file *);
void hid_debug_register(struct hid_device *, const char *);
void hid_debug_unregister(struct hid_device *);
void hid_debug_init(void);
void hid_debug_exit(void);
void hid_debug_event(struct hid_device *, char *);
struct hid_debug_list {
DECLARE_KFIFO_PTR(hid_debug_fifo, char);
struct fasync_struct *fasync;
struct hid_device *hdev;
struct list_head node;
struct mutex read_mutex;
};
#else
#define hid_dump_input(a,b,c) do { } while (0)
#define hid_dump_report(a,b,c,d) do { } while (0)
#define hid_dump_device(a,b) do { } while (0)
#define hid_dump_field(a,b,c) do { } while (0)
#define hid_resolv_usage(a,b) do { } while (0)
#define hid_debug_register(a, b) do { } while (0)
#define hid_debug_unregister(a) do { } while (0)
#define hid_debug_init() do { } while (0)
#define hid_debug_exit() do { } while (0)
#define hid_debug_event(a,b) do { } while (0)
#endif
#endif