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3d09fc4244
In the function tipc_nodesub_notify() we call a function pointer aggregated into the object to be notified, whereafter we set the function pointer to NULL. However, in some cases the function pointed to will free the struct containing the function pointer, resulting in a write to already freed memory. This bug seems to always have been there, without causing any notable harm. In this commit we fix the problem by inverting the order of the zeroing and the function call. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
97 lines
3.3 KiB
C
97 lines
3.3 KiB
C
/*
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* net/tipc/node_subscr.c: TIPC "node down" subscription handling
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*
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* Copyright (c) 1995-2006, Ericsson AB
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* Copyright (c) 2005, 2010-2011, Wind River Systems
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the names of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* Alternatively, this software may be distributed under the terms of the
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* GNU General Public License ("GPL") version 2 as published by the Free
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* Software Foundation.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "core.h"
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#include "node_subscr.h"
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#include "node.h"
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/**
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* tipc_nodesub_subscribe - create "node down" subscription for specified node
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*/
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void tipc_nodesub_subscribe(struct tipc_node_subscr *node_sub, u32 addr,
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void *usr_handle, net_ev_handler handle_down)
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{
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if (in_own_node(addr)) {
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node_sub->node = NULL;
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return;
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}
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node_sub->node = tipc_node_find(addr);
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if (!node_sub->node) {
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pr_warn("Node subscription rejected, unknown node 0x%x\n",
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addr);
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return;
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}
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node_sub->handle_node_down = handle_down;
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node_sub->usr_handle = usr_handle;
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tipc_node_lock(node_sub->node);
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list_add_tail(&node_sub->nodesub_list, &node_sub->node->nsub);
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tipc_node_unlock(node_sub->node);
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}
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/**
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* tipc_nodesub_unsubscribe - cancel "node down" subscription (if any)
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*/
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void tipc_nodesub_unsubscribe(struct tipc_node_subscr *node_sub)
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{
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if (!node_sub->node)
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return;
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tipc_node_lock(node_sub->node);
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list_del_init(&node_sub->nodesub_list);
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tipc_node_unlock(node_sub->node);
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}
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/**
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* tipc_nodesub_notify - notify subscribers that a node is unreachable
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*
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* Note: node is locked by caller
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*/
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void tipc_nodesub_notify(struct list_head *nsub_list)
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{
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struct tipc_node_subscr *ns, *safe;
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net_ev_handler handle_node_down;
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list_for_each_entry_safe(ns, safe, nsub_list, nodesub_list) {
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handle_node_down = ns->handle_node_down;
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if (handle_node_down) {
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ns->handle_node_down = NULL;
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handle_node_down(ns->usr_handle);
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}
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}
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}
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