e65f7ee39b
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable cn_callback_entry.refcnt is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
89 lines
2.4 KiB
C
89 lines
2.4 KiB
C
/*
|
|
* connector.h
|
|
*
|
|
* 2004-2005 Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
|
|
* All rights reserved.
|
|
*
|
|
* 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
|
|
*/
|
|
#ifndef __CONNECTOR_H
|
|
#define __CONNECTOR_H
|
|
|
|
|
|
#include <linux/refcount.h>
|
|
|
|
#include <linux/list.h>
|
|
#include <linux/workqueue.h>
|
|
|
|
#include <net/sock.h>
|
|
#include <uapi/linux/connector.h>
|
|
|
|
#define CN_CBQ_NAMELEN 32
|
|
|
|
struct cn_queue_dev {
|
|
atomic_t refcnt;
|
|
unsigned char name[CN_CBQ_NAMELEN];
|
|
|
|
struct list_head queue_list;
|
|
spinlock_t queue_lock;
|
|
|
|
struct sock *nls;
|
|
};
|
|
|
|
struct cn_callback_id {
|
|
unsigned char name[CN_CBQ_NAMELEN];
|
|
struct cb_id id;
|
|
};
|
|
|
|
struct cn_callback_entry {
|
|
struct list_head callback_entry;
|
|
refcount_t refcnt;
|
|
struct cn_queue_dev *pdev;
|
|
|
|
struct cn_callback_id id;
|
|
void (*callback) (struct cn_msg *, struct netlink_skb_parms *);
|
|
|
|
u32 seq, group;
|
|
};
|
|
|
|
struct cn_dev {
|
|
struct cb_id id;
|
|
|
|
u32 seq, groups;
|
|
struct sock *nls;
|
|
void (*input) (struct sk_buff *skb);
|
|
|
|
struct cn_queue_dev *cbdev;
|
|
};
|
|
|
|
int cn_add_callback(struct cb_id *id, const char *name,
|
|
void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
|
|
void cn_del_callback(struct cb_id *);
|
|
int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 group, gfp_t gfp_mask);
|
|
int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask);
|
|
|
|
int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
|
|
struct cb_id *id,
|
|
void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
|
|
void cn_queue_del_callback(struct cn_queue_dev *dev, struct cb_id *id);
|
|
void cn_queue_release_callback(struct cn_callback_entry *);
|
|
|
|
struct cn_queue_dev *cn_queue_alloc_dev(const char *name, struct sock *);
|
|
void cn_queue_free_dev(struct cn_queue_dev *dev);
|
|
|
|
int cn_cb_equal(struct cb_id *, struct cb_id *);
|
|
|
|
#endif /* __CONNECTOR_H */
|