------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.155/6661 is trying to acquire lock:
ffffffff8e2d6ba0 (console_owner){....}-{0:0}, at: console_lock_spinning_enable+0x61/0x80 kernel/printk/printk.c:1900

but task is already holding lock:
ffff88801b4a8018 (&pool->lock){-.-.}-{2:2}, at: destroy_workqueue+0x1e2/0xab0 kernel/workqueue.c:5920

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&pool->lock){-.-.}-{2:2}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       __queue_work+0x26b/0x10e0 kernel/workqueue.c:2295
       queue_work_on+0x15f/0x1f0 kernel/workqueue.c:2386
       queue_work include/linux/workqueue.h:669 [inline]
       rpm_suspend+0xe8f/0x11b0 drivers/base/power/runtime.c:688
       rpm_idle+0x5dc/0x760 drivers/base/power/runtime.c:562
       __pm_runtime_idle+0xba/0x1a0 drivers/base/power/runtime.c:1129
       pm_runtime_put include/linux/pm_runtime.h:563 [inline]
       __device_attach+0x37e/0x4e0 drivers/base/dd.c:1049
       device_initial_probe+0xaa/0xc0 drivers/base/dd.c:1086
       bus_probe_device+0x64/0x150 drivers/base/bus.c:574
       device_add+0x116e/0x1980 drivers/base/core.c:3689
       serial_base_port_add+0x227/0x2b0 drivers/tty/serial/serial_base_bus.c:183
       serial_core_port_device_add drivers/tty/serial/serial_core.c:3252 [inline]
       serial_core_register_port+0x13c/0x25d0 drivers/tty/serial/serial_core.c:3291
       serial8250_register_8250_port+0x155a/0x2380 drivers/tty/serial/8250/8250_core.c:822
       serial_pnp_probe+0x431/0x930 drivers/tty/serial/8250/8250_pnp.c:480
       pnp_device_probe+0x2a8/0x4d0 drivers/pnp/driver.c:111
       call_driver_probe drivers/base/dd.c:581 [inline]
       really_probe+0x241/0xb20 drivers/base/dd.c:659
       __driver_probe_device+0x1de/0x470 drivers/base/dd.c:801
       driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:831
       __driver_attach+0x283/0x5e0 drivers/base/dd.c:1225
       bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
       bus_add_driver+0x30f/0x6c0 drivers/base/bus.c:715
       driver_register+0x15c/0x4b0 drivers/base/driver.c:249
       serial8250_init+0xca/0x1e0 drivers/tty/serial/8250/8250_platform.c:317
       do_one_initcall+0x123/0x680 init/main.c:1378
       do_initcall_level init/main.c:1440 [inline]
       do_initcalls init/main.c:1456 [inline]
       do_basic_setup init/main.c:1475 [inline]
       kernel_init_freeable+0x5c8/0x920 init/main.c:1688
       kernel_init+0x1c/0x2b0 init/main.c:1578
       ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

-> #2 (&dev->power.lock){-...}-{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
       __pm_runtime_resume+0xa9/0x170 drivers/base/power/runtime.c:1196
       pm_runtime_get include/linux/pm_runtime.h:494 [inline]
       __uart_start+0x1b0/0x500 drivers/tty/serial/serial_core.c:149
       uart_write+0x218/0xb30 drivers/tty/serial/serial_core.c:633
       process_output_block drivers/tty/n_tty.c:557 [inline]
       n_tty_write+0x434/0x1280 drivers/tty/n_tty.c:2366
       iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
       file_tty_write.constprop.0+0x503/0x9b0 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+0xd4/0x120 drivers/tty/tty_io.c:1105
       new_sync_write fs/read_write.c:593 [inline]
       vfs_write+0x7d3/0x11d0 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/0xf80 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:3301
       console_emit_next_record kernel/printk/printk.c:3129 [inline]
       console_flush_one_record+0x796/0xc60 kernel/printk/printk.c:3215
       console_flush_all kernel/printk/printk.c:3289 [inline]
       __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
       console_unlock+0xef/0x240 kernel/printk/printk.c:3359
       vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426
       _printk+0xc7/0x100 kernel/printk/printk.c:2451
       register_console+0x823/0x1210 kernel/printk/printk.c:4170
       univ8250_console_init+0x5f/0x90 drivers/tty/serial/8250/8250_core.c:515
       console_init+0x152/0x600 kernel/printk/printk.c:4369
       start_kernel+0x298/0x4d0 init/main.c:1143
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
       x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
       common_startup_64+0x13e/0x148

-> #0 (console_owner){....}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x1669/0x2890 kernel/locking/lockdep.c:5237
       lock_acquire kernel/locking/lockdep.c:5868 [inline]
       lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
       console_lock_spinning_enable+0x72/0x80 kernel/printk/printk.c:1900
       console_emit_next_record kernel/printk/printk.c:3123 [inline]
       console_flush_one_record+0x73f/0xc60 kernel/printk/printk.c:3215
       console_flush_all kernel/printk/printk.c:3289 [inline]
       __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
       console_unlock+0xef/0x240 kernel/printk/printk.c:3359
       vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426
       _printk+0xc7/0x100 kernel/printk/printk.c:2451
       __report_bug+0x3a6/0x520 lib/bug.c:239
       report_bug+0xb2/0x220 lib/bug.c:277
       handle_bug+0x127/0x260 arch/x86/kernel/traps.c:435
       exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:489
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:616
       destroy_workqueue+0x322/0xab0 kernel/workqueue.c:5921
       nci_unregister_device+0x68/0x300 net/nfc/nci/core.c:1314
       virtual_ncidev_close+0x4b/0xa0 drivers/nfc/virtual_ncidev.c:172
       __fput+0x402/0xb70 fs/file_table.c:468
       task_work_run+0x150/0x240 kernel/task_work.c:233
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
       exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75
       __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
       syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
       syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
       syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
       do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  console_owner --> &dev->power.lock --> &pool->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&pool->lock);
                               lock(&dev->power.lock);
                               lock(&pool->lock);
  lock(console_owner);

 *** DEADLOCK ***

5 locks held by syz.2.155/6661:
 #0: ffffffff8e27f148 (wq_pool_mutex){+.+.}-{4:4}, at: destroy_workqueue+0x178/0xab0 kernel/workqueue.c:5917
 #1: ffff8880245e4088 (&wq->mutex){+.+.}-{4:4}, at: destroy_workqueue+0x183/0xab0 kernel/workqueue.c:5918
 #2: ffff88801b4a8018 (&pool->lock){-.-.}-{2:2}, at: destroy_workqueue+0x1e2/0xab0 kernel/workqueue.c:5920
 #3: ffffffff8e3b6fe0 (console_lock){+.+.}-{0:0}, at: _printk+0xc7/0x100 kernel/printk/printk.c:2451
 #4: ffffffff8e3b7058 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:336 [inline]
 #4: ffffffff8e3b7058 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:409 [inline]
 #4: ffffffff8e3b7058 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:289 [inline]
 #4: ffffffff8e3b7058 (console_srcu){....}-{0:0}, at: console_flush_one_record+0x103/0xc60 kernel/printk/printk.c:3192

stack backtrace:
CPU: 1 UID: 0 PID: 6661 Comm: syz.2.155 Not tainted syzkaller #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
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x275/0x340 kernel/locking/lockdep.c:2043
 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x1669/0x2890 kernel/locking/lockdep.c:5237
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
 console_lock_spinning_enable+0x72/0x80 kernel/printk/printk.c:1900
 console_emit_next_record kernel/printk/printk.c:3123 [inline]
 console_flush_one_record+0x73f/0xc60 kernel/printk/printk.c:3215
 console_flush_all kernel/printk/printk.c:3289 [inline]
 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
 console_unlock+0xef/0x240 kernel/printk/printk.c:3359
 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426
 _printk+0xc7/0x100 kernel/printk/printk.c:2451
 __report_bug+0x3a6/0x520 lib/bug.c:239
 report_bug+0xb2/0x220 lib/bug.c:277
 handle_bug+0x127/0x260 arch/x86/kernel/traps.c:435
 exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:489
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:616
RIP: 0010:destroy_workqueue+0x322/0xab0 kernel/workqueue.c:5921
Code: e8 d3 85 39 00 49 8d 6d 68 48 89 e8 48 c1 e8 03 42 80 3c 30 00 0f 85 35 07 00 00 49 8b 45 68 48 39 c5 74 7f e8 af 85 39 00 90 <0f> 0b 90 48 c7 c6 20 71 8c 8b 48 8d 93 78 01 00 00 48 c7 c7 40 66
RSP: 0018:ffffc90005a97d10 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff8880245e4000 RCX: ffffffff81855d13
RDX: ffff8880246024c0 RSI: ffffffff81855e11 RDI: 0000000000000005
RBP: ffff88802b600024 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff888024602ff0 R12: 0000000000000002
R13: ffff88802b600000 R14: dffffc0000000000 R15: 0000000000000001
 nci_unregister_device+0x68/0x300 net/nfc/nci/core.c:1314
 virtual_ncidev_close+0x4b/0xa0 drivers/nfc/virtual_ncidev.c:172
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f17bb58f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd4b4b1bb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f17bb7e7da0 RCX: 00007f17bb58f7c9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f17bb7e7da0 R08: 0000000000000834 R09: 000000084b4b1eaf
R10: 00000000003ff5a8 R11: 0000000000000246 R12: 0000000000011b81
R13: 00007f17bb7e6090 R14: ffffffffffffffff R15: 00007ffd4b4b1cd0
 </TASK>
WARNING: kernel/workqueue.c:5921 at destroy_workqueue+0x322/0xab0 kernel/workqueue.c:5921, CPU#1: syz.2.155/6661
Modules linked in:
CPU: 1 UID: 0 PID: 6661 Comm: syz.2.155 Not tainted syzkaller #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
RIP: 0010:destroy_workqueue+0x322/0xab0 kernel/workqueue.c:5921
Code: e8 d3 85 39 00 49 8d 6d 68 48 89 e8 48 c1 e8 03 42 80 3c 30 00 0f 85 35 07 00 00 49 8b 45 68 48 39 c5 74 7f e8 af 85 39 00 90 <0f> 0b 90 48 c7 c6 20 71 8c 8b 48 8d 93 78 01 00 00 48 c7 c7 40 66
RSP: 0018:ffffc90005a97d10 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff8880245e4000 RCX: ffffffff81855d13
RDX: ffff8880246024c0 RSI: ffffffff81855e11 RDI: 0000000000000005
RBP: ffff88802b600024 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff888024602ff0 R12: 0000000000000002
R13: ffff88802b600000 R14: dffffc0000000000 R15: 0000000000000001
FS:  000055556d08e500(0000) GS:ffff8880d69fb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f17bc362f98 CR3: 000000005724b000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 nci_unregister_device+0x68/0x300 net/nfc/nci/core.c:1314
 virtual_ncidev_close+0x4b/0xa0 drivers/nfc/virtual_ncidev.c:172
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f17bb58f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd4b4b1bb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f17bb7e7da0 RCX: 00007f17bb58f7c9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f17bb7e7da0 R08: 0000000000000834 R09: 000000084b4b1eaf
R10: 00000000003ff5a8 R11: 0000000000000246 R12: 0000000000011b81
R13: 00007f17bb7e6090 R14: ffffffffffffffff R15: 00007ffd4b4b1cd0
 </TASK>