------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc1-syzkaller-00203-g4774cfe3543a #0 Not tainted
------------------------------------------------------
kworker/u32:2/46 is trying to acquire lock:
ffffffff8e4d1dc0 (console_owner){....}-{0:0}, at: console_lock_spinning_enable+0x9f/0xd0 kernel/printk/printk.c:1924

but task is already holding lock:
ffff88806a63bc98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:606

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:606
       raw_spin_rq_lock kernel/sched/sched.h:1532 [inline]
       task_rq_lock+0xcf/0x490 kernel/sched/core.c:708
       cgroup_move_task+0x81/0x2a0 kernel/sched/psi.c:1161
       css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:918
       cgroup_post_fork+0x201/0x9e0 kernel/cgroup/cgroup.c:6754
       copy_process+0x5cfc/0x76a0 kernel/fork.c:2413
       kernel_clone+0xfc/0x960 kernel/fork.c:2599
       user_mode_thread+0xc7/0x110 kernel/fork.c:2677
       rest_init+0x23/0x2b0 init/main.c:709
       start_kernel+0x3ee/0x4d0 init/main.c:1101
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
       x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
       common_startup_64+0x13e/0x148

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
       try_to_wake_up+0xb2/0x1680 kernel/sched/core.c:4226
       __wake_up_common+0x135/0x1f0 kernel/sched/wait.c:89
       __wake_up_common_lock kernel/sched/wait.c:106 [inline]
       __wake_up+0x31/0x60 kernel/sched/wait.c:127
       tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1838
       serial8250_handle_irq+0x761/0xcb0 drivers/tty/serial/8250/8250_port.c:1946
       serial8250_default_handle_irq+0x9a/0x210 drivers/tty/serial/8250/8250_port.c:1966
       serial8250_interrupt+0x103/0x210 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x229/0x7d0 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210
       handle_edge_irq+0x28e/0xab0 kernel/irq/chip.c:789
       generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
       handle_irq arch/x86/kernel/irq.c:254 [inline]
       call_irq_handler arch/x86/kernel/irq.c:266 [inline]
       __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:292
       common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:285
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81
       arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
       default_idle+0x13/0x20 arch/x86/kernel/process.c:749
       default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
       cpuidle_idle_call kernel/sched/idle.c:185 [inline]
       do_idle+0x391/0x510 kernel/sched/idle.c:325
       cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
       rest_init+0x16b/0x2b0 init/main.c:744
       start_kernel+0x3ee/0x4d0 init/main.c:1101
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
       x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
       common_startup_64+0x13e/0x148

-> #2 (&tty->write_wait){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       __wake_up_common_lock kernel/sched/wait.c:105 [inline]
       __wake_up+0x1c/0x60 kernel/sched/wait.c:127
       tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1838
       __start_tx+0x3e9/0x4a0 drivers/tty/serial/8250/8250_port.c:1543
       serial8250_start_tx+0x368/0x530 drivers/tty/serial/8250/8250_port.c:1653
       __uart_start+0x292/0x4c0 drivers/tty/serial/serial_core.c:161
       uart_write+0x218/0xb30 drivers/tty/serial/serial_core.c:636
       process_output_block drivers/tty/n_tty.c:561 [inline]
       n_tty_write+0x40f/0x1160 drivers/tty/n_tty.c:2377
       iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
       file_tty_write.constprop.0+0x504/0x9b0 drivers/tty/tty_io.c:1081
       tty_write drivers/tty/tty_io.c:1102 [inline]
       redirected_tty_write drivers/tty/tty_io.c:1125 [inline]
       redirected_tty_write+0xd4/0x150 drivers/tty/tty_io.c:1105
       new_sync_write fs/read_write.c:593 [inline]
       vfs_write+0x6c4/0x1150 fs/read_write.c:686
       ksys_write+0x12a/0x250 fs/read_write.c:738
       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
       do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{3:3}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:717 [inline]
       serial8250_console_write+0x181/0x1890 drivers/tty/serial/8250/8250_port.c:3415
       console_emit_next_record kernel/printk/printk.c:3138 [inline]
       console_flush_all+0x801/0xc60 kernel/printk/printk.c:3226
       __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
       console_unlock+0xd8/0x210 kernel/printk/printk.c:3325
       vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450
       _printk+0xc7/0x100 kernel/printk/printk.c:2475
       register_console+0xc2d/0x11b0 kernel/printk/printk.c:4125
       univ8250_console_init+0x5f/0x90 drivers/tty/serial/8250/8250_core.c:513
       console_init+0x14f/0x680 kernel/printk/printk.c:4323
       start_kernel+0x29f/0x4d0 init/main.c:1035
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
       x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
       common_startup_64+0x13e/0x148

-> #0 (console_owner){....}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3168 [inline]
       check_prevs_add kernel/locking/lockdep.c:3287 [inline]
       validate_chain kernel/locking/lockdep.c:3911 [inline]
       __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
       lock_acquire kernel/locking/lockdep.c:5871 [inline]
       lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
       console_lock_spinning_enable+0xb0/0xd0 kernel/printk/printk.c:1924
       console_emit_next_record kernel/printk/printk.c:3132 [inline]
       console_flush_all+0x7aa/0xc60 kernel/printk/printk.c:3226
       __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
       console_unlock+0xd8/0x210 kernel/printk/printk.c:3325
       vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450
       _printk+0xc7/0x100 kernel/printk/printk.c:2475
       __warn_printk+0x157/0x350 kernel/panic.c:823
       native_smp_send_reschedule+0x55/0x70 arch/x86/kernel/apic/ipi.c:71
       arch_smp_send_reschedule arch/x86/include/asm/smp.h:90 [inline]
       __resched_curr+0x2a3/0x3a0 kernel/sched/core.c:1122
       wakeup_preempt+0x115/0x320 kernel/sched/core.c:2200
       ttwu_do_activate+0x1c3/0xb10 kernel/sched/core.c:3747
       ttwu_queue kernel/sched/core.c:4014 [inline]
       try_to_wake_up+0x76e/0x1680 kernel/sched/core.c:4342
       kthread_stop+0x18a/0x650 kernel/kthread.c:790
       destroy_workqueue+0x154/0xaa0 kernel/workqueue.c:5883
       wg_destruct+0x24d/0x3d0 drivers/net/wireguard/device.c:257
       netdev_run_todo+0x78c/0x1320 net/core/dev.c:11405
       default_device_exit_batch+0x858/0xaf0 net/core/dev.c:12645
       ops_exit_list net/core/net_namespace.c:206 [inline]
       ops_undo_list+0x363/0xab0 net/core/net_namespace.c:253
       cleanup_net+0x408/0x890 net/core/net_namespace.c:686
       process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
       process_scheduled_works kernel/workqueue.c:3321 [inline]
       worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
       kthread+0x3c2/0x780 kernel/kthread.c:464
       ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

other info that might help us debug this:

Chain exists of:
  console_owner --> &p->pi_lock --> &rq->__lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&rq->__lock);
                               lock(&p->pi_lock);
                               lock(&rq->__lock);
  lock(console_owner);

 *** DEADLOCK ***

8 locks held by kworker/u32:2/46:
 #0: ffff88801ca8d148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc900007efd10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffffffff90336cd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662
 #3: ffff8880399554e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x151/0x3d0 drivers/net/wireguard/device.c:249
 #4: ffff88802a1952a8 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
 #4: ffff88802a1952a8 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb2/0x1680 kernel/sched/core.c:4226
 #5: ffff88806a63bc98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:606
 #6: ffffffff8e5b2200 (console_lock){+.+.}-{0:0}, at: _printk+0xc7/0x100 kernel/printk/printk.c:2475
 #7: ffffffff8e5b2270 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
 #7: ffffffff8e5b2270 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:346 [inline]
 #7: ffffffff8e5b2270 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
 #7: ffffffff8e5b2270 (console_srcu){....}-{0:0}, at: console_flush_all+0x158/0xc60 kernel/printk/printk.c:3203

stack backtrace:
CPU: 3 UID: 0 PID: 46 Comm: kworker/u32:2 Not tainted 6.16.0-rc1-syzkaller-00203-g4774cfe3543a #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2046
 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3168 [inline]
 check_prevs_add kernel/locking/lockdep.c:3287 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
 lock_acquire kernel/locking/lockdep.c:5871 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
 console_lock_spinning_enable+0xb0/0xd0 kernel/printk/printk.c:1924
 console_emit_next_record kernel/printk/printk.c:3132 [inline]
 console_flush_all+0x7aa/0xc60 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xd8/0x210 kernel/printk/printk.c:3325
 vprintk_emit+0x418/0x6d0 kernel/printk/printk.c:2450
 _printk+0xc7/0x100 kernel/printk/printk.c:2475
 __warn_printk+0x157/0x350 kernel/panic.c:823
 native_smp_send_reschedule+0x55/0x70 arch/x86/kernel/apic/ipi.c:71
 arch_smp_send_reschedule arch/x86/include/asm/smp.h:90 [inline]
 __resched_curr+0x2a3/0x3a0 kernel/sched/core.c:1122
 wakeup_preempt+0x115/0x320 kernel/sched/core.c:2200
 ttwu_do_activate+0x1c3/0xb10 kernel/sched/core.c:3747
 ttwu_queue kernel/sched/core.c:4014 [inline]
 try_to_wake_up+0x76e/0x1680 kernel/sched/core.c:4342
 kthread_stop+0x18a/0x650 kernel/kthread.c:790
 destroy_workqueue+0x154/0xaa0 kernel/workqueue.c:5883
 wg_destruct+0x24d/0x3d0 drivers/net/wireguard/device.c:257
 netdev_run_todo+0x78c/0x1320 net/core/dev.c:11405
 default_device_exit_batch+0x858/0xaf0 net/core/dev.c:12645
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x363/0xab0 net/core/net_namespace.c:253
 cleanup_net+0x408/0x890 net/core/net_namespace.c:686
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
sched: Unexpected reschedule of offline CPU#2!
WARNING: CPU: 3 PID: 46 at arch/x86/kernel/apic/ipi.c:71 native_smp_send_reschedule+0x56/0x70 arch/x86/kernel/apic/ipi.c:71
Modules linked in:
CPU: 3 UID: 0 PID: 46 Comm: kworker/u32:2 Not tainted 6.16.0-rc1-syzkaller-00203-g4774cfe3543a #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: netns cleanup_net
RIP: 0010:native_smp_send_reschedule+0x56/0x70 arch/x86/kernel/apic/ipi.c:71
Code: a0 bf 3f 0f 73 14 89 df be fd 00 00 00 5b 5d e9 90 29 01 00 90 0f 0b 90 eb c7 90 48 c7 c7 c0 8a a9 8b 89 de e8 db 8f 12 00 90 <0f> 0b 90 90 5b 5d e9 7f a1 1a 0a 66 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc900007ef5e0 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffffffff817ae248
RDX: ffff88801c33a440 RSI: ffffffff817ae255 RDI: 0000000000000001
RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 55203a6465686373 R12: 0000000000000003
R13: 1ffff920000fdebf R14: 0000000000000002 R15: ffffc900007ef618
FS:  0000000000000000(0000) GS:ffff8880d6a54000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b166e7d60 CR3: 000000000e382000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_smp_send_reschedule arch/x86/include/asm/smp.h:90 [inline]
 __resched_curr+0x2a3/0x3a0 kernel/sched/core.c:1122
 wakeup_preempt+0x115/0x320 kernel/sched/core.c:2200
 ttwu_do_activate+0x1c3/0xb10 kernel/sched/core.c:3747
 ttwu_queue kernel/sched/core.c:4014 [inline]
 try_to_wake_up+0x76e/0x1680 kernel/sched/core.c:4342
 kthread_stop+0x18a/0x650 kernel/kthread.c:790
 destroy_workqueue+0x154/0xaa0 kernel/workqueue.c:5883
 wg_destruct+0x24d/0x3d0 drivers/net/wireguard/device.c:257
 netdev_run_todo+0x78c/0x1320 net/core/dev.c:11405
 default_device_exit_batch+0x858/0xaf0 net/core/dev.c:12645
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x363/0xab0 net/core/net_namespace.c:253
 cleanup_net+0x408/0x890 net/core/net_namespace.c:686
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>