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linux-next/net/tipc/discover.h
Ying Xue a8b9b96e95 tipc: fix race in disc create/delete
Commit a21a584d67 (tipc: fix neighbor
detection problem after hw address change) introduces a race condition
involving tipc_disc_delete() and tipc_disc_add/remove_dest that can
cause TIPC to dereference the pointer to the bearer discovery request
structure after it has been freed since a stray pointer is left in the
bearer structure.

In order to fix the issue, the process of resetting the discovery
request handler is optimized: the discovery request handler and request
buffer are just reset instead of being freed, allocated and initialized.
As the request point is always valid and the request's lock is taken
while the request handler is reset, the race doesn't happen any more.

Reported-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Tested-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-22 21:17:53 -04:00

50 lines
2.2 KiB
C

/*
* net/tipc/discover.h
*
* Copyright (c) 2003-2006, Ericsson AB
* Copyright (c) 2005, 2010-2011, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _TIPC_DISCOVER_H
#define _TIPC_DISCOVER_H
struct tipc_link_req;
int tipc_disc_create(struct tipc_bearer *b_ptr, struct tipc_media_addr *dest);
void tipc_disc_delete(struct tipc_link_req *req);
void tipc_disc_reset(struct tipc_bearer *b_ptr);
void tipc_disc_add_dest(struct tipc_link_req *req);
void tipc_disc_remove_dest(struct tipc_link_req *req);
void tipc_disc_rcv(struct sk_buff *buf, struct tipc_bearer *b_ptr);
#endif