forked from mirrors/linux
		
	 13054abbaa
			
		
	
	
		13054abbaa
		
	
	
	
	
		
			
			Ring buffer implementation in hid_debug_event() and hid_debug_events_read() is strange allowing lost or corrupted data. After commit717adfdaf1("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>
		
			
				
	
	
		
			66 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			66 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef __HID_DEBUG_H
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| #define __HID_DEBUG_H
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| 
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| /*
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|  *  Copyright (c) 2007-2009	Jiri Kosina
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|  */
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| 
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| /*
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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|  *
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|  */
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| 
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| #ifdef CONFIG_DEBUG_FS
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| 
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| #include <linux/kfifo.h>
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| 
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| #define HID_DEBUG_BUFSIZE 512
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| #define HID_DEBUG_FIFOSIZE 512
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| 
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| void hid_dump_input(struct hid_device *, struct hid_usage *, __s32);
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| void hid_dump_report(struct hid_device *, int , u8 *, int);
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| void hid_dump_device(struct hid_device *, struct seq_file *);
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| void hid_dump_field(struct hid_field *, int, struct seq_file *);
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| char *hid_resolv_usage(unsigned, struct seq_file *);
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| void hid_debug_register(struct hid_device *, const char *);
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| void hid_debug_unregister(struct hid_device *);
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| void hid_debug_init(void);
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| void hid_debug_exit(void);
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| void hid_debug_event(struct hid_device *, char *);
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| 
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| struct hid_debug_list {
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| 	DECLARE_KFIFO_PTR(hid_debug_fifo, char);
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| 	struct fasync_struct *fasync;
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| 	struct hid_device *hdev;
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| 	struct list_head node;
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| 	struct mutex read_mutex;
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| };
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| 
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| #else
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| 
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| #define hid_dump_input(a,b,c)		do { } while (0)
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| #define hid_dump_report(a,b,c,d)	do { } while (0)
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| #define hid_dump_device(a,b)		do { } while (0)
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| #define hid_dump_field(a,b,c)		do { } while (0)
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| #define hid_resolv_usage(a,b)		do { } while (0)
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| #define hid_debug_register(a, b)	do { } while (0)
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| #define hid_debug_unregister(a)		do { } while (0)
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| #define hid_debug_init()		do { } while (0)
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| #define hid_debug_exit()		do { } while (0)
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| #define hid_debug_event(a,b)		do { } while (0)
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| 
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| #endif
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| 
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| #endif
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