------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc7-syzkaller-00216-gf66d6acccbc0 #0 Not tainted
------------------------------------------------------
kworker/1:2/1210 is trying to acquire lock:
ffffffff8e0c5680 (console_owner){..-.}-{0:0}, at: console_lock_spinning_enable+0x9f/0xd0 kernel/printk/printk.c:1905

but task is already holding lock:
ffff8880b873eed8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 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}:
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:598
       raw_spin_rq_lock kernel/sched/sched.h:1506 [inline]
       task_rq_lock+0xcf/0x3b0 kernel/sched/core.c:700
       cgroup_move_task+0x82/0x250 kernel/sched/psi.c:1161
       css_set_move_task+0x288/0x5f0 kernel/cgroup/cgroup.c:898
       cgroup_post_fork+0x1c6/0x910 kernel/cgroup/cgroup.c:6692
       copy_process+0x51a5/0x8cb0 kernel/fork.c:2600
       kernel_clone+0xfd/0x960 kernel/fork.c:2786
       user_mode_thread+0xb4/0xf0 kernel/fork.c:2864
       rest_init+0x23/0x2b0 init/main.c:712
       start_kernel+0x3e4/0x4d0 init/main.c:1105
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488
       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:551 [inline]
       try_to_wake_up+0xa1/0x14f0 kernel/sched/core.c:4165
       __wake_up_common+0x134/0x1e0 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:1821
       serial8250_handle_irq+0x74d/0xc80 drivers/tty/serial/8250/8250_port.c:1929
       serial8250_default_handle_irq+0x9a/0x210 drivers/tty/serial/8250/8250_port.c:1949
       serial8250_interrupt+0x106/0x210 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x22c/0x7c0 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+0x263/0xd10 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+0xe2/0x250 arch/x86/kernel/irq.c:285
       common_interrupt+0xba/0xe0 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+0x1a/0x20 drivers/acpi/processor_idle.c:111
       acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:702
       cpuidle_enter_state+0xad/0x4f0 drivers/cpuidle/cpuidle.c:264
       cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:385
       cpuidle_idle_call kernel/sched/idle.c:230 [inline]
       do_idle+0x313/0x3f0 kernel/sched/idle.c:326
       cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:424
       start_secondary+0x222/0x2b0 arch/x86/kernel/smpboot.c:314
       common_startup_64+0x13e/0x148

-> #2 (&tty->write_wait){-.-.}-{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
       __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:1821
       serial8250_handle_irq+0x74d/0xc80 drivers/tty/serial/8250/8250_port.c:1929
       serial8250_default_handle_irq+0x9a/0x210 drivers/tty/serial/8250/8250_port.c:1949
       serial8250_interrupt+0x106/0x210 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x22c/0x7c0 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+0x263/0xd10 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+0xe2/0x250 arch/x86/kernel/irq.c:285
       common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:278
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
       _raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_port_unlock_irqrestore include/linux/serial_core.h:782 [inline]
       uart_write+0x2a4/0xb30 drivers/tty/serial/serial_core.c:636
       process_output_block drivers/tty/n_tty.c:574 [inline]
       n_tty_write+0x41c/0x1140 drivers/tty/n_tty.c:2389
       iterate_tty_write drivers/tty/tty_io.c:1015 [inline]
       file_tty_write.constprop.0+0x509/0x9a0 drivers/tty/tty_io.c:1090
       tty_write drivers/tty/tty_io.c:1111 [inline]
       redirected_tty_write drivers/tty/tty_io.c:1134 [inline]
       redirected_tty_write+0xcc/0x140 drivers/tty/tty_io.c:1114
       new_sync_write fs/read_write.c:590 [inline]
       vfs_write+0x5b1/0x1150 fs/read_write.c:683
       ksys_write+0x12f/0x260 fs/read_write.c:736
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{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
       uart_port_lock_irqsave include/linux/serial_core.h:711 [inline]
       serial8250_console_write+0xb56/0x17c0 drivers/tty/serial/8250/8250_port.c:3352
       console_emit_next_record kernel/printk/printk.c:3092 [inline]
       console_flush_all+0x803/0xc60 kernel/printk/printk.c:3180
       __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
       console_unlock+0xd9/0x210 kernel/printk/printk.c:3279
       vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2407
       vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68
       _printk+0xc8/0x100 kernel/printk/printk.c:2432
       register_console+0xbfd/0x1170 kernel/printk/printk.c:4069
       univ8250_console_init+0x5f/0x90 drivers/tty/serial/8250/8250_core.c:513
       console_init+0xcc/0x680 kernel/printk/printk.c:4262
       start_kernel+0x29a/0x4d0 init/main.c:1040
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x148

-> #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 kernel/locking/lockdep.c:3904 [inline]
       __lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
       console_lock_spinning_enable+0xb0/0xd0 kernel/printk/printk.c:1905
       console_emit_next_record kernel/printk/printk.c:3086 [inline]
       console_flush_all+0x7ac/0xc60 kernel/printk/printk.c:3180
       __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
       console_unlock+0xd9/0x210 kernel/printk/printk.c:3279
       vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2407
       vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68
       _printk+0xc8/0x100 kernel/printk/printk.c:2432
       __report_bug lib/bug.c:195 [inline]
       report_bug+0x4ac/0x580 lib/bug.c:219
       handle_bug+0x54/0xa0 arch/x86/kernel/traps.c:285
       exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:309
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
       enqueue_dl_entity+0x1390/0x2a60 kernel/sched/deadline.c:1995
       dl_server_start+0xb9/0x700 kernel/sched/deadline.c:1650
       enqueue_task_fair+0x550/0xfb0 kernel/sched/fair.c:7044
       enqueue_task+0x7b/0x3e0 kernel/sched/core.c:2020
       activate_task+0x54/0xd0 kernel/sched/core.c:2067
       attach_task+0x116/0x1b0 kernel/sched/fair.c:9641
       attach_tasks kernel/sched/fair.c:9676 [inline]
       sched_balance_rq+0x1456/0x2ec0 kernel/sched/fair.c:11753
       sched_balance_newidle+0x6bb/0x1190 kernel/sched/fair.c:12795
       pick_next_task_fair+0x50/0x1280 kernel/sched/fair.c:8943
       __pick_next_task+0xf1/0x6c0 kernel/sched/core.c:5971
       pick_next_task kernel/sched/core.c:6069 [inline]
       __schedule+0x42c/0x5740 kernel/sched/core.c:6647
       __schedule_loop kernel/sched/core.c:6770 [inline]
       schedule+0xe7/0x350 kernel/sched/core.c:6785
       worker_thread+0x2de/0xf00 kernel/workqueue.c:3406
       kthread+0x2c4/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x48/0x80 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 ***

4 locks held by kworker/1:2/1210:
 #0: ffffffff8e1b83c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_release include/linux/rcupdate.h:347 [inline]
 #0: ffffffff8e1b83c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_unlock include/linux/rcupdate.h:880 [inline]
 #0: ffffffff8e1b83c0 (rcu_read_lock){....}-{1:2}, at: sched_balance_newidle+0x47c/0x1190 kernel/sched/fair.c:12777
 #1: ffff8880b873eed8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:598
 #2: ffffffff8e1a5ac0 (console_lock){+.+.}-{0:0}, at: vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68
 #3: ffffffff8e1a5b30 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline]
 #3: ffffffff8e1a5b30 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:267 [inline]
 #3: ffffffff8e1a5b30 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
 #3: ffffffff8e1a5b30 (console_srcu){....}-{0:0}, at: console_flush_all+0x159/0xc60 kernel/printk/printk.c:3157

stack backtrace:
CPU: 1 UID: 0 PID: 1210 Comm: kworker/1:2 Not tainted 6.12.0-rc7-syzkaller-00216-gf66d6acccbc0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue:  0x0 (events)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x41c/0x610 kernel/locking/lockdep.c:2074
 check_noncircular+0x31a/0x400 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 kernel/locking/lockdep.c:3904 [inline]
 __lock_acquire+0x250b/0x3ce0 kernel/locking/lockdep.c:5202
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
 console_lock_spinning_enable+0xb0/0xd0 kernel/printk/printk.c:1905
 console_emit_next_record kernel/printk/printk.c:3086 [inline]
 console_flush_all+0x7ac/0xc60 kernel/printk/printk.c:3180
 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline]
 console_unlock+0xd9/0x210 kernel/printk/printk.c:3279
 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2407
 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68
 _printk+0xc8/0x100 kernel/printk/printk.c:2432
 __report_bug lib/bug.c:195 [inline]
 report_bug+0x4ac/0x580 lib/bug.c:219
 handle_bug+0x54/0xa0 arch/x86/kernel/traps.c:285
 exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:309
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0010:enqueue_dl_entity+0x1390/0x2a60 kernel/sched/deadline.c:1995
Code: f1 ff ff 44 8b 1c 24 45 85 db 0f 84 07 fa ff ff 48 83 c4 28 44 89 e6 48 89 cf 5b 5d 41 5c 41 5d 41 5e 41 5f e9 61 67 ff ff 90 <0f> 0b 90 e9 a0 ec ff ff 90 0f 0b 90 e9 44 f3 ff ff 45 84 f6 0f 85
RSP: 0018:ffffc9000467f700 EFLAGS: 00010082
RAX: dffffc0000000000 RBX: ffff8880b873f8a8 RCX: ffff8880b873f8a8
RDX: 1ffff110170e7f15 RSI: 0000000000000001 RDI: ffff8880b873f8a8
RBP: ffff8880b873f8fc R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff905f854f R11: 0000000000000000 R12: 0000000000000001
R13: ffff8880b873eec0 R14: 000000000016e360 R15: dffffc0000000000
 dl_server_start+0xb9/0x700 kernel/sched/deadline.c:1650
 enqueue_task_fair+0x550/0xfb0 kernel/sched/fair.c:7044
 enqueue_task+0x7b/0x3e0 kernel/sched/core.c:2020
 activate_task+0x54/0xd0 kernel/sched/core.c:2067
 attach_task+0x116/0x1b0 kernel/sched/fair.c:9641
 attach_tasks kernel/sched/fair.c:9676 [inline]
 sched_balance_rq+0x1456/0x2ec0 kernel/sched/fair.c:11753
 sched_balance_newidle+0x6bb/0x1190 kernel/sched/fair.c:12795
 pick_next_task_fair+0x50/0x1280 kernel/sched/fair.c:8943
 __pick_next_task+0xf1/0x6c0 kernel/sched/core.c:5971
 pick_next_task kernel/sched/core.c:6069 [inline]
 __schedule+0x42c/0x5740 kernel/sched/core.c:6647
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6785
 worker_thread+0x2de/0xf00 kernel/workqueue.c:3406
 kthread+0x2c4/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
WARNING: CPU: 1 PID: 1210 at kernel/sched/deadline.c:1995 enqueue_dl_entity+0x1390/0x2a60 kernel/sched/deadline.c:1995
Modules linked in:
CPU: 1 UID: 0 PID: 1210 Comm: kworker/1:2 Not tainted 6.12.0-rc7-syzkaller-00216-gf66d6acccbc0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Workqueue:  0x0 (events)
RIP: 0010:enqueue_dl_entity+0x1390/0x2a60 kernel/sched/deadline.c:1995
Code: f1 ff ff 44 8b 1c 24 45 85 db 0f 84 07 fa ff ff 48 83 c4 28 44 89 e6 48 89 cf 5b 5d 41 5c 41 5d 41 5e 41 5f e9 61 67 ff ff 90 <0f> 0b 90 e9 a0 ec ff ff 90 0f 0b 90 e9 44 f3 ff ff 45 84 f6 0f 85
RSP: 0018:ffffc9000467f700 EFLAGS: 00010082
RAX: dffffc0000000000 RBX: ffff8880b873f8a8 RCX: ffff8880b873f8a8
RDX: 1ffff110170e7f15 RSI: 0000000000000001 RDI: ffff8880b873f8a8
RBP: ffff8880b873f8fc R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff905f854f R11: 0000000000000000 R12: 0000000000000001
R13: ffff8880b873eec0 R14: 000000000016e360 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f82a4910d58 CR3: 000000000df7c000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 dl_server_start+0xb9/0x700 kernel/sched/deadline.c:1650
 enqueue_task_fair+0x550/0xfb0 kernel/sched/fair.c:7044
 enqueue_task+0x7b/0x3e0 kernel/sched/core.c:2020
 activate_task+0x54/0xd0 kernel/sched/core.c:2067
 attach_task+0x116/0x1b0 kernel/sched/fair.c:9641
 attach_tasks kernel/sched/fair.c:9676 [inline]
 sched_balance_rq+0x1456/0x2ec0 kernel/sched/fair.c:11753
 sched_balance_newidle+0x6bb/0x1190 kernel/sched/fair.c:12795
 pick_next_task_fair+0x50/0x1280 kernel/sched/fair.c:8943
 __pick_next_task+0xf1/0x6c0 kernel/sched/core.c:5971
 pick_next_task kernel/sched/core.c:6069 [inline]
 __schedule+0x42c/0x5740 kernel/sched/core.c:6647
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6785
 worker_thread+0x2de/0xf00 kernel/workqueue.c:3406
 kthread+0x2c4/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>