vcan0: j1939_tp_rxtimer: 0xffff88807d948000: rx timeout, send abort vcan0: j1939_xtp_rx_abort_one: 0xffff88807d948000: 0x00000: (3) A timeout occurred and this is the connection abort to close the session. ====================================================== WARNING: possible circular locking dependency detected 6.2.0-rc6-syzkaller-00174-g0b6d6425103a #0 Not tainted ------------------------------------------------------ ksoftirqd/1/21 is trying to acquire lock: ffff888058be9088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] ffff888058be9088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_list_lock net/can/j1939/transport.c:238 [inline] ffff888058be9088 (&priv->active_session_list_lock){+.-.}-{2:2}, at: j1939_session_activate+0x47/0x4b0 net/can/j1939/transport.c:1557 but task is already holding lock: ffff8880228995c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] ffff8880228995c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_activate_next+0x5f/0x450 net/can/j1939/socket.c:207 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&jsk->sk_session_queue_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_sk_queue_drop_all+0x3b/0x2f0 net/can/j1939/socket.c:139 j1939_sk_netdev_event_netdown+0x7f/0x160 net/can/j1939/socket.c:1275 j1939_netdev_notify+0x19d/0x1d0 net/can/j1939/main.c:379 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline] call_netdevice_notifiers net/core/dev.c:1996 [inline] __dev_notify_flags+0x1ea/0x2d0 net/core/dev.c:8571 dev_change_flags+0x11b/0x170 net/core/dev.c:8607 do_setlink+0x9f1/0x3bb0 net/core/rtnetlink.c:2827 __rtnl_newlink+0xd69/0x1840 net/core/rtnetlink.c:3590 rtnl_newlink+0x68/0xa0 net/core/rtnetlink.c:3637 rtnetlink_rcv_msg+0x43e/0xca0 net/core/rtnetlink.c:6141 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2574 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1942 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (&priv->j1939_socks_lock){+.-.}-{2:2}: __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_sk_errqueue+0xa3/0x1a0 net/can/j1939/socket.c:1081 __j1939_session_cancel+0x3b9/0x460 net/can/j1939/transport.c:1128 j1939_tp_rxtimer.cold+0x19a/0x1e6 net/can/j1939/transport.c:1253 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x690/0xfb0 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17f/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x9/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 lock_acquire+0x227/0x630 kernel/locking/lockdep.c:5636 rcu_lock_acquire include/linux/rcupdate.h:325 [inline] rcu_read_lock include/linux/rcupdate.h:764 [inline] inet_twsk_purge+0x132/0x8a0 net/ipv4/inet_timewait_sock.c:295 ops_exit_list+0x125/0x170 net/core/net_namespace.c:174 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:606 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 -> #0 (&priv->active_session_list_lock){+.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x47/0x4b0 net/can/j1939/transport.c:1557 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x1b6/0x450 net/can/j1939/socket.c:208 j1939_session_deactivate_activate_next+0x69/0x72 net/can/j1939/transport.c:1105 j1939_xtp_rx_abort_one.cold+0x301/0x403 net/can/j1939/transport.c:1344 j1939_xtp_rx_abort net/can/j1939/transport.c:1355 [inline] j1939_tp_cmd_recv net/can/j1939/transport.c:2104 [inline] j1939_tp_recv+0xb63/0xcd0 net/can/j1939/transport.c:2137 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78e/0xa30 net/can/j1939/main.c:38 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:606 can_receive+0x31d/0x580 net/can/af_can.c:663 can_rcv+0x1e1/0x230 net/can/af_can.c:687 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5482 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5596 process_backlog+0x3e4/0x810 net/core/dev.c:5924 __napi_poll+0xb8/0x770 net/core/dev.c:6485 napi_poll net/core/dev.c:6552 [inline] net_rx_action+0xa00/0xde0 net/core/dev.c:6663 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:934 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:926 smpboot_thread_fn+0x659/0xa20 kernel/smpboot.c:164 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 other info that might help us debug this: Chain exists of: &priv->active_session_list_lock --> &priv->j1939_socks_lock --> &jsk->sk_session_queue_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&jsk->sk_session_queue_lock); lock(&priv->j1939_socks_lock); lock(&jsk->sk_session_queue_lock); lock(&priv->active_session_list_lock); *** DEADLOCK *** 3 locks held by ksoftirqd/1/21: #0: ffffffff8c790300 (rcu_read_lock){....}-{1:2}, at: __skb_unlink include/linux/skbuff.h:2327 [inline] #0: ffffffff8c790300 (rcu_read_lock){....}-{1:2}, at: __skb_dequeue include/linux/skbuff.h:2342 [inline] #0: ffffffff8c790300 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x38f/0x810 net/core/dev.c:5922 #1: ffffffff8c790300 (rcu_read_lock){....}-{1:2}, at: can_receive+0x1ef/0x580 net/can/af_can.c:653 #2: ffff8880228995c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:355 [inline] #2: ffff8880228995c8 (&jsk->sk_session_queue_lock){+.-.}-{2:2}, at: j1939_sk_queue_activate_next+0x5f/0x450 net/can/j1939/socket.c:207 stack backtrace: CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.2.0-rc6-syzkaller-00174-g0b6d6425103a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:355 [inline] j1939_session_list_lock net/can/j1939/transport.c:238 [inline] j1939_session_activate+0x47/0x4b0 net/can/j1939/transport.c:1557 j1939_sk_queue_activate_next_locked net/can/j1939/socket.c:181 [inline] j1939_sk_queue_activate_next+0x1b6/0x450 net/can/j1939/socket.c:208 j1939_session_deactivate_activate_next+0x69/0x72 net/can/j1939/transport.c:1105 j1939_xtp_rx_abort_one.cold+0x301/0x403 net/can/j1939/transport.c:1344 j1939_xtp_rx_abort net/can/j1939/transport.c:1355 [inline] j1939_tp_cmd_recv net/can/j1939/transport.c:2104 [inline] j1939_tp_recv+0xb63/0xcd0 net/can/j1939/transport.c:2137 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78e/0xa30 net/can/j1939/main.c:38 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:606 can_receive+0x31d/0x580 net/can/af_can.c:663 can_rcv+0x1e1/0x230 net/can/af_can.c:687 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5482 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5596 process_backlog+0x3e4/0x810 net/core/dev.c:5924 __napi_poll+0xb8/0x770 net/core/dev.c:6485 napi_poll net/core/dev.c:6552 [inline] net_rx_action+0xa00/0xde0 net/core/dev.c:6663 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:934 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:926 smpboot_thread_fn+0x659/0xa20 kernel/smpboot.c:164 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 vcan0: j1939_tp_rxtimer: 0xffff888059828400: rx timeout, send abort vcan0: j1939_xtp_rx_abort_one: 0xffff888059828400: 0x00000: (3) A timeout occurred and this is the connection abort to close the session. vcan0: j1939_tp_rxtimer: 0xffff88807c34fc00: rx timeout, send abort vcan0: j1939_xtp_rx_abort_one: 0xffff88807c34fc00: 0x00000: (3) A timeout occurred and this is the connection abort to close the session.