1946014ca3
Current code can lead to the following race: CPU0 CPU1 rxrpc_exit_net() rxrpc_peer_keepalive_worker() if (rxnet->live) rxnet->live = false; del_timer_sync(&rxnet->peer_keepalive_timer); timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay); cancel_work_sync(&rxnet->peer_keepalive_work); rxrpc_exit_net() exits while peer_keepalive_timer is still armed, leading to use-after-free. syzbot report was: ODEBUG: free active (active state 0) object type: timer_list hint: rxrpc_peer_keepalive_timeout+0x0/0xb0 WARNING: CPU: 0 PID: 3660 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505 Modules linked in: CPU: 0 PID: 3660 Comm: kworker/u4:6 Not tainted 5.17.0-syzkaller-13993-g88e6c0207623 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:505 Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd 00 1c 26 8a 4c 89 ee 48 c7 c7 00 10 26 8a e8 b1 e7 28 05 <0f> 0b 83 05 15 eb c5 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3 RSP: 0018:ffffc9000353fb00 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: ffff888029196140 RSI: ffffffff815efad8 RDI: fffff520006a7f52 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815ea4ae R11: 0000000000000000 R12: ffffffff89ce23e0 R13: ffffffff8a2614e0 R14: ffffffff816628c0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f2908924 CR3: 0000000043720000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __debug_check_no_obj_freed lib/debugobjects.c:992 [inline] debug_check_no_obj_freed+0x301/0x420 lib/debugobjects.c:1023 kfree+0xd6/0x310 mm/slab.c:3809 ops_free_list.part.0+0x119/0x370 net/core/net_namespace.c:176 ops_free_list net/core/net_namespace.c:174 [inline] cleanup_net+0x591/0xb00 net/core/net_namespace.c:598 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 </TASK> Fixes: ace45bec6d77 ("rxrpc: Fix firewall route keepalive") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: David Howells <dhowells@redhat.com> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: linux-afs@lists.infradead.org Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
131 lines
3.6 KiB
C
131 lines
3.6 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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cancel_work_sync(&rxnet->peer_keepalive_work);
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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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