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c3317f4db8
When a topology subscription is created, we may encounter (or KASAN
may provoke) a failure to create a corresponding service instance in
the binding table. Instead of letting the tipc_nametbl_subscribe()
report the failure back to the caller, the function just makes a warning
printout and returns, without incrementing the subscription reference
counter as expected by the caller.
This makes the caller believe that the subscription was successful, so
it will at a later moment try to unsubscribe the item. This involves
a sub_put() call. Since the reference counter never was incremented
in the first place, we get a premature delete of the subscription item,
followed by a "use-after-free" warning.
We fix this by adding a return value to tipc_nametbl_subscribe() and
make the caller aware of the failure to subscribe.
This bug seems to always have been around, but this fix only applies
back to the commit shown below. Given the low risk of this happening
we believe this to be sufficient.
Fixes: commit 218527fe27
("tipc: replace name table service range
array with rb tree")
Reported-by: syzbot+aa245f26d42b8305d157@syzkaller.appspotmail.com
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
175 lines
5.4 KiB
C
175 lines
5.4 KiB
C
/*
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* net/tipc/subscr.c: TIPC network topology service
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*
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* Copyright (c) 2000-2017, Ericsson AB
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* Copyright (c) 2005-2007, 2010-2013, 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 "name_table.h"
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#include "subscr.h"
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static void tipc_sub_send_event(struct tipc_subscription *sub,
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u32 found_lower, u32 found_upper,
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u32 event, u32 port, u32 node)
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{
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struct tipc_event *evt = &sub->evt;
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if (sub->inactive)
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return;
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tipc_evt_write(evt, event, event);
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tipc_evt_write(evt, found_lower, found_lower);
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tipc_evt_write(evt, found_upper, found_upper);
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tipc_evt_write(evt, port.ref, port);
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tipc_evt_write(evt, port.node, node);
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tipc_topsrv_queue_evt(sub->net, sub->conid, event, evt);
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}
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/**
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* tipc_sub_check_overlap - test for subscription overlap with the
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* given values
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*
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* Returns 1 if there is overlap, otherwise 0.
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*/
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int tipc_sub_check_overlap(struct tipc_name_seq *seq, u32 found_lower,
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u32 found_upper)
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{
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if (found_lower < seq->lower)
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found_lower = seq->lower;
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if (found_upper > seq->upper)
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found_upper = seq->upper;
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if (found_lower > found_upper)
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return 0;
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return 1;
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}
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void tipc_sub_report_overlap(struct tipc_subscription *sub,
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u32 found_lower, u32 found_upper,
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u32 event, u32 port, u32 node,
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u32 scope, int must)
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{
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struct tipc_subscr *s = &sub->evt.s;
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u32 filter = tipc_sub_read(s, filter);
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struct tipc_name_seq seq;
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seq.type = tipc_sub_read(s, seq.type);
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seq.lower = tipc_sub_read(s, seq.lower);
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seq.upper = tipc_sub_read(s, seq.upper);
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if (!tipc_sub_check_overlap(&seq, found_lower, found_upper))
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return;
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if (!must && !(filter & TIPC_SUB_PORTS))
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return;
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if (filter & TIPC_SUB_CLUSTER_SCOPE && scope == TIPC_NODE_SCOPE)
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return;
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if (filter & TIPC_SUB_NODE_SCOPE && scope != TIPC_NODE_SCOPE)
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return;
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spin_lock(&sub->lock);
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tipc_sub_send_event(sub, found_lower, found_upper,
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event, port, node);
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spin_unlock(&sub->lock);
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}
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static void tipc_sub_timeout(struct timer_list *t)
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{
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struct tipc_subscription *sub = from_timer(sub, t, timer);
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struct tipc_subscr *s = &sub->evt.s;
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spin_lock(&sub->lock);
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tipc_sub_send_event(sub, s->seq.lower, s->seq.upper,
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TIPC_SUBSCR_TIMEOUT, 0, 0);
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sub->inactive = true;
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spin_unlock(&sub->lock);
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}
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static void tipc_sub_kref_release(struct kref *kref)
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{
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kfree(container_of(kref, struct tipc_subscription, kref));
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}
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void tipc_sub_put(struct tipc_subscription *subscription)
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{
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kref_put(&subscription->kref, tipc_sub_kref_release);
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}
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void tipc_sub_get(struct tipc_subscription *subscription)
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{
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kref_get(&subscription->kref);
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}
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struct tipc_subscription *tipc_sub_subscribe(struct net *net,
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struct tipc_subscr *s,
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int conid)
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{
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u32 filter = tipc_sub_read(s, filter);
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struct tipc_subscription *sub;
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u32 timeout;
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if ((filter & TIPC_SUB_PORTS && filter & TIPC_SUB_SERVICE) ||
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(tipc_sub_read(s, seq.lower) > tipc_sub_read(s, seq.upper))) {
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pr_warn("Subscription rejected, illegal request\n");
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return NULL;
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}
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sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
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if (!sub) {
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pr_warn("Subscription rejected, no memory\n");
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return NULL;
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}
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INIT_LIST_HEAD(&sub->service_list);
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INIT_LIST_HEAD(&sub->sub_list);
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sub->net = net;
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sub->conid = conid;
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sub->inactive = false;
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memcpy(&sub->evt.s, s, sizeof(*s));
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spin_lock_init(&sub->lock);
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kref_init(&sub->kref);
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if (!tipc_nametbl_subscribe(sub)) {
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kfree(sub);
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return NULL;
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}
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timer_setup(&sub->timer, tipc_sub_timeout, 0);
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timeout = tipc_sub_read(&sub->evt.s, timeout);
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if (timeout != TIPC_WAIT_FOREVER)
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mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout));
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return sub;
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}
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void tipc_sub_unsubscribe(struct tipc_subscription *sub)
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{
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tipc_nametbl_unsubscribe(sub);
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if (sub->evt.s.timeout != TIPC_WAIT_FOREVER)
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del_timer_sync(&sub->timer);
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list_del(&sub->sub_list);
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tipc_sub_put(sub);
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}
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