forked from luck/tmp_suning_uos_patched
60592f16a4
[ Upstream commit ee3b0826b4764f6c13ad6db67495c5a1c38e9025 ] A recent patch[1] from Eric Dumazet flipped the order in which the keepalive timer and the keepalive worker were cancelled in order to fix a syzbot reported issue[2]. Unfortunately, this enables the mirror image bug whereby the timer races with rxrpc_exit_net(), restarting the worker after it has been cancelled: CPU 1 CPU 2 =============== ===================== if (rxnet->live) <INTERRUPT> rxnet->live = false; cancel_work_sync(&rxnet->peer_keepalive_work); rxrpc_queue_work(&rxnet->peer_keepalive_work); del_timer_sync(&rxnet->peer_keepalive_timer); Fix this by restoring the removed del_timer_sync() so that we try to remove the timer twice. If the timer runs again, it should see ->live == false and not restart the worker. Fixes: 1946014ca3b1 ("rxrpc: fix a race in rxrpc_exit_net()") Signed-off-by: David Howells <dhowells@redhat.com> cc: Eric Dumazet <edumazet@google.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20220404183439.3537837-1-eric.dumazet@gmail.com/ [1] Link: https://syzkaller.appspot.com/bug?extid=724378c4bb58f703b09a [2] Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
133 lines
3.7 KiB
C
133 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* rxrpc network namespace handling.
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*
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* Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#include <linux/proc_fs.h>
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#include "ar-internal.h"
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unsigned int rxrpc_net_id;
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static void rxrpc_client_conn_reap_timeout(struct timer_list *timer)
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{
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struct rxrpc_net *rxnet =
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container_of(timer, struct rxrpc_net, client_conn_reap_timer);
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if (rxnet->live)
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rxrpc_queue_work(&rxnet->client_conn_reaper);
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}
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static void rxrpc_service_conn_reap_timeout(struct timer_list *timer)
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{
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struct rxrpc_net *rxnet =
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container_of(timer, struct rxrpc_net, service_conn_reap_timer);
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if (rxnet->live)
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rxrpc_queue_work(&rxnet->service_conn_reaper);
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}
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static void rxrpc_peer_keepalive_timeout(struct timer_list *timer)
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{
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struct rxrpc_net *rxnet =
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container_of(timer, struct rxrpc_net, peer_keepalive_timer);
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if (rxnet->live)
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rxrpc_queue_work(&rxnet->peer_keepalive_work);
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}
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/*
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* Initialise a per-network namespace record.
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*/
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static __net_init int rxrpc_init_net(struct net *net)
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{
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struct rxrpc_net *rxnet = rxrpc_net(net);
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int ret, i;
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rxnet->live = true;
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get_random_bytes(&rxnet->epoch, sizeof(rxnet->epoch));
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rxnet->epoch |= RXRPC_RANDOM_EPOCH;
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INIT_LIST_HEAD(&rxnet->calls);
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rwlock_init(&rxnet->call_lock);
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atomic_set(&rxnet->nr_calls, 1);
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atomic_set(&rxnet->nr_conns, 1);
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INIT_LIST_HEAD(&rxnet->conn_proc_list);
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INIT_LIST_HEAD(&rxnet->service_conns);
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rwlock_init(&rxnet->conn_lock);
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INIT_WORK(&rxnet->service_conn_reaper,
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rxrpc_service_connection_reaper);
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timer_setup(&rxnet->service_conn_reap_timer,
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rxrpc_service_conn_reap_timeout, 0);
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atomic_set(&rxnet->nr_client_conns, 0);
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rxnet->kill_all_client_conns = false;
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spin_lock_init(&rxnet->client_conn_cache_lock);
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spin_lock_init(&rxnet->client_conn_discard_lock);
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INIT_LIST_HEAD(&rxnet->idle_client_conns);
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INIT_WORK(&rxnet->client_conn_reaper,
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rxrpc_discard_expired_client_conns);
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timer_setup(&rxnet->client_conn_reap_timer,
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rxrpc_client_conn_reap_timeout, 0);
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INIT_LIST_HEAD(&rxnet->local_endpoints);
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mutex_init(&rxnet->local_mutex);
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hash_init(rxnet->peer_hash);
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spin_lock_init(&rxnet->peer_hash_lock);
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for (i = 0; i < ARRAY_SIZE(rxnet->peer_keepalive); i++)
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INIT_LIST_HEAD(&rxnet->peer_keepalive[i]);
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INIT_LIST_HEAD(&rxnet->peer_keepalive_new);
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timer_setup(&rxnet->peer_keepalive_timer,
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rxrpc_peer_keepalive_timeout, 0);
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INIT_WORK(&rxnet->peer_keepalive_work, rxrpc_peer_keepalive_worker);
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rxnet->peer_keepalive_base = ktime_get_seconds();
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ret = -ENOMEM;
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rxnet->proc_net = proc_net_mkdir(net, "rxrpc", net->proc_net);
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if (!rxnet->proc_net)
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goto err_proc;
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proc_create_net("calls", 0444, rxnet->proc_net, &rxrpc_call_seq_ops,
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sizeof(struct seq_net_private));
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proc_create_net("conns", 0444, rxnet->proc_net,
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&rxrpc_connection_seq_ops,
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sizeof(struct seq_net_private));
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proc_create_net("peers", 0444, rxnet->proc_net,
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&rxrpc_peer_seq_ops,
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sizeof(struct seq_net_private));
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return 0;
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err_proc:
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rxnet->live = false;
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return ret;
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}
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/*
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* Clean up a per-network namespace record.
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*/
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static __net_exit void rxrpc_exit_net(struct net *net)
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{
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struct rxrpc_net *rxnet = rxrpc_net(net);
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rxnet->live = false;
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del_timer_sync(&rxnet->peer_keepalive_timer);
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cancel_work_sync(&rxnet->peer_keepalive_work);
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/* Remove the timer again as the worker may have restarted it. */
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del_timer_sync(&rxnet->peer_keepalive_timer);
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rxrpc_destroy_all_calls(rxnet);
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rxrpc_destroy_all_connections(rxnet);
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rxrpc_destroy_all_peers(rxnet);
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rxrpc_destroy_all_locals(rxnet);
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proc_remove(rxnet->proc_net);
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}
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struct pernet_operations rxrpc_net_ops = {
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.init = rxrpc_init_net,
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.exit = rxrpc_exit_net,
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.id = &rxrpc_net_id,
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.size = sizeof(struct rxrpc_net),
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};
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