------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc7-syzkaller-g2c8b09ac2537 #0 Not tainted
------------------------------------------------------
kworker/u8:14/6459 is trying to acquire lock:
ffffffff8e815360 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline]
ffffffff8e815360 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:267 [inline]
ffffffff8e815360 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
ffffffff8e815360 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3157

but task is already holding lock:
ffff8880b863ead8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&rq->__lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
       raw_spin_rq_lock kernel/sched/sched.h:1506 [inline]
       task_rq_lock+0xc6/0x360 kernel/sched/core.c:700
       cgroup_move_task+0x9b/0x5a0 kernel/sched/psi.c:1161
       css_set_move_task+0x72e/0x950 kernel/cgroup/cgroup.c:898
       cgroup_post_fork+0x256/0x880 kernel/cgroup/cgroup.c:6692
       copy_process+0x39e9/0x3d50 kernel/fork.c:2600
       kernel_clone+0x226/0x8f0 kernel/fork.c:2786
       user_mode_thread+0x132/0x1a0 kernel/fork.c:2864
       rest_init+0x23/0x300 init/main.c:712
       start_kernel+0x47f/0x500 init/main.c:1105
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x147

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
       try_to_wake_up+0xbe/0x14b0 kernel/sched/core.c:4165
       __wake_up_common kernel/sched/wait.c:89 [inline]
       __wake_up_common_lock+0x130/0x1e0 kernel/sched/wait.c:106
       tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1821
       serial8250_handle_irq+0x630/0xb80 drivers/tty/serial/8250/8250_port.c:1929
       serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1949
       serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x29a/0xa80 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
       handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
       handle_irq arch/x86/kernel/irq.c:247 [inline]
       call_irq_handler arch/x86/kernel/irq.c:259 [inline]
       __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:285
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:278
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
       acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111
       acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:702
       cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:264
       cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:385
       call_cpuidle kernel/sched/idle.c:155 [inline]
       cpuidle_idle_call kernel/sched/idle.c:230 [inline]
       do_idle+0x375/0x5d0 kernel/sched/idle.c:326
       cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424
       rest_init+0x2dc/0x300 init/main.c:747
       start_kernel+0x47f/0x500 init/main.c:1105
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x147

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       __wake_up_common_lock+0x25/0x1e0 kernel/sched/wait.c:105
       tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1821
       serial8250_handle_irq+0x630/0xb80 drivers/tty/serial/8250/8250_port.c:1929
       serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1949
       serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x29a/0xa80 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x89/0x1f0 kernel/irq/handle.c:210
       handle_edge_irq+0x25f/0xc20 kernel/irq/chip.c:831
       generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
       handle_irq arch/x86/kernel/irq.c:247 [inline]
       call_irq_handler arch/x86/kernel/irq.c:259 [inline]
       __common_interrupt+0x136/0x230 arch/x86/kernel/irq.c:285
       common_interrupt+0xb4/0xd0 arch/x86/kernel/irq.c:278
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
       arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
       acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111
       acpi_idle_enter+0xe4/0x140 drivers/acpi/processor_idle.c:702
       cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:264
       cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:385
       call_cpuidle kernel/sched/idle.c:155 [inline]
       cpuidle_idle_call kernel/sched/idle.c:230 [inline]
       do_idle+0x375/0x5d0 kernel/sched/idle.c:326
       cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:424
       rest_init+0x2dc/0x300 init/main.c:747
       start_kernel+0x47f/0x500 init/main.c:1105
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x147

-> #1 (&port_lock_key){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:711 [inline]
       serial8250_console_write+0x1a7/0x1ed0 drivers/tty/serial/8250/8250_port.c:3352
       console_emit_next_record kernel/printk/printk.c:3092 [inline]
       console_flush_all+0x86b/0xeb0 kernel/printk/printk.c:3180
       __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
       console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279
       vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407
       _printk+0xd5/0x120 kernel/printk/printk.c:2432
       register_console+0xbf5/0xfd0 kernel/printk/printk.c:4069
       univ8250_console_init+0x52/0x90 drivers/tty/serial/8250/8250_core.c:513
       console_init+0x1b8/0x6f0 kernel/printk/printk.c:4262
       start_kernel+0x2d8/0x500 init/main.c:1040
       x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x147

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       console_lock_spinning_enable kernel/printk/printk.c:1905 [inline]
       console_emit_next_record kernel/printk/printk.c:3086 [inline]
       console_flush_all+0x7f8/0xeb0 kernel/printk/printk.c:3180
       __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
       console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279
       vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407
       _printk+0xd5/0x120 kernel/printk/printk.c:2432
       __report_bug lib/bug.c:195 [inline]
       report_bug+0x346/0x500 lib/bug.c:219
       handle_bug+0x60/0x90 arch/x86/kernel/traps.c:285
       exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:309
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
       enqueue_dl_entity+0x1630/0x1d60 kernel/sched/deadline.c:1995
       dl_server_start+0xc9/0x240 kernel/sched/deadline.c:1650
       enqueue_task_fair+0xb5c/0xea0 kernel/sched/fair.c:7044
       enqueue_task+0x7a/0x340 kernel/sched/core.c:2020
       activate_task+0x61/0xc0 kernel/sched/core.c:2067
       attach_task+0xee/0x190 kernel/sched/fair.c:9641
       attach_tasks kernel/sched/fair.c:9676 [inline]
       sched_balance_rq+0x664a/0x8620 kernel/sched/fair.c:11753
       sched_balance_newidle+0x6ba/0xfd0 kernel/sched/fair.c:12795
       pick_next_task_fair+0x40/0xc90 kernel/sched/fair.c:8943
       __pick_next_task+0xdd/0x400 kernel/sched/core.c:5971
       __schedule+0x776/0x4c30 kernel/sched/core.c:6647
       __schedule_loop kernel/sched/core.c:6770 [inline]
       schedule+0x14b/0x320 kernel/sched/core.c:6785
       schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6842
       __mutex_lock_common kernel/locking/mutex.c:684 [inline]
       __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
       linkwatch_event+0xe/0x60 net/core/link_watch.c:276
       process_one_work kernel/workqueue.c:3229 [inline]
       process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
       worker_thread+0x870/0xd30 kernel/workqueue.c:3391
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

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 ***

7 locks held by kworker/u8:14/6459:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900184afd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900184afd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcd5b48 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
 #3: ffffffff8e939de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #3: ffffffff8e939de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8e939de0 (rcu_read_lock){....}-{1:2}, at: sched_balance_newidle+0x2c0/0xfd0 kernel/sched/fair.c:12765
 #4: ffff8880b863ead8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
 #5: ffffffff8e8153c0 (console_lock){+.+.}-{0:0}, at: _printk+0xd5/0x120 kernel/printk/printk.c:2432
 #6: ffffffff8e814fd0 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline]
 #6: ffffffff8e814fd0 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:267 [inline]
 #6: ffffffff8e814fd0 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
 #6: ffffffff8e814fd0 (console_srcu){....}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3157

stack backtrace:
CPU: 0 UID: 0 PID: 6459 Comm: kworker/u8:14 Not tainted 6.12.0-rc7-syzkaller-g2c8b09ac2537 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 console_lock_spinning_enable kernel/printk/printk.c:1905 [inline]
 console_emit_next_record kernel/printk/printk.c:3086 [inline]
 console_flush_all+0x7f8/0xeb0 kernel/printk/printk.c:3180
 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
 console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279
 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407
 _printk+0xd5/0x120 kernel/printk/printk.c:2432
 __report_bug lib/bug.c:195 [inline]
 report_bug+0x346/0x500 lib/bug.c:219
 handle_bug+0x60/0x90 arch/x86/kernel/traps.c:285
 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:309
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0010:enqueue_dl_entity+0x1630/0x1d60 kernel/sched/deadline.c:1995
Code: df 0f b6 04 08 84 c0 0f 85 cf 02 00 00 8b 75 00 48 89 df 4c 89 ea 48 83 c4 58 5b 41 5c 41 5d 41 5e 41 5f 5d e9 d1 1f ff ff 90 <0f> 0b 90 e9 09 ea ff ff 90 0f 0b 90 e9 c4 fb ff ff 90 0f 0b 90 e9
RSP: 0018:ffffc900184aedb0 EFLAGS: 00010017
RAX: dffffc0000000000 RBX: ffff8880b863f4c0 RCX: 1ffff110170c7e95
RDX: ffffffff81686240 RSI: 0000000000000001 RDI: ffff8880b863f4a8
RBP: 0000000000000001 R08: ffff888033049827 R09: 0000000000000000
R10: ffff888033049810 R11: ffffed1006609305 R12: ffff8880b863f4a8
R13: ffff8880b863f4a8 R14: ffff8880b863f4fc R15: ffff8880b863f580
 dl_server_start+0xc9/0x240 kernel/sched/deadline.c:1650
 enqueue_task_fair+0xb5c/0xea0 kernel/sched/fair.c:7044
 enqueue_task+0x7a/0x340 kernel/sched/core.c:2020
 activate_task+0x61/0xc0 kernel/sched/core.c:2067
 attach_task+0xee/0x190 kernel/sched/fair.c:9641
 attach_tasks kernel/sched/fair.c:9676 [inline]
 sched_balance_rq+0x664a/0x8620 kernel/sched/fair.c:11753
 sched_balance_newidle+0x6ba/0xfd0 kernel/sched/fair.c:12795
 pick_next_task_fair+0x40/0xc90 kernel/sched/fair.c:8943
 __pick_next_task+0xdd/0x400 kernel/sched/core.c:5971
 __schedule+0x776/0x4c30 kernel/sched/core.c:6647
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6785
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6842
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 linkwatch_event+0xe/0x60 net/core/link_watch.c:276
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
WARNING: CPU: 0 PID: 6459 at kernel/sched/deadline.c:1995 enqueue_dl_entity+0x1630/0x1d60 kernel/sched/deadline.c:1995
Modules linked in:
CPU: 0 UID: 0 PID: 6459 Comm: kworker/u8:14 Not tainted 6.12.0-rc7-syzkaller-g2c8b09ac2537 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue: events_unbound linkwatch_event
RIP: 0010:enqueue_dl_entity+0x1630/0x1d60 kernel/sched/deadline.c:1995
Code: df 0f b6 04 08 84 c0 0f 85 cf 02 00 00 8b 75 00 48 89 df 4c 89 ea 48 83 c4 58 5b 41 5c 41 5d 41 5e 41 5f 5d e9 d1 1f ff ff 90 <0f> 0b 90 e9 09 ea ff ff 90 0f 0b 90 e9 c4 fb ff ff 90 0f 0b 90 e9
RSP: 0018:ffffc900184aedb0 EFLAGS: 00010017
RAX: dffffc0000000000 RBX: ffff8880b863f4c0 RCX: 1ffff110170c7e95
RDX: ffffffff81686240 RSI: 0000000000000001 RDI: ffff8880b863f4a8
RBP: 0000000000000001 R08: ffff888033049827 R09: 0000000000000000
R10: ffff888033049810 R11: ffffed1006609305 R12: ffff8880b863f4a8
R13: ffff8880b863f4a8 R14: ffff8880b863f4fc R15: ffff8880b863f580
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3ad909 CR3: 0000000065f5c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 dl_server_start+0xc9/0x240 kernel/sched/deadline.c:1650
 enqueue_task_fair+0xb5c/0xea0 kernel/sched/fair.c:7044
 enqueue_task+0x7a/0x340 kernel/sched/core.c:2020
 activate_task+0x61/0xc0 kernel/sched/core.c:2067
 attach_task+0xee/0x190 kernel/sched/fair.c:9641
 attach_tasks kernel/sched/fair.c:9676 [inline]
 sched_balance_rq+0x664a/0x8620 kernel/sched/fair.c:11753
 sched_balance_newidle+0x6ba/0xfd0 kernel/sched/fair.c:12795
 pick_next_task_fair+0x40/0xc90 kernel/sched/fair.c:8943
 __pick_next_task+0xdd/0x400 kernel/sched/core.c:5971
 __schedule+0x776/0x4c30 kernel/sched/core.c:6647
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6785
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6842
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 linkwatch_event+0xe/0x60 net/core/link_watch.c:276
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>