------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc1-syzkaller #0 Not tainted
------------------------------------------------------
kworker/u8:5/4337 is trying to acquire lock:
ffffffff8465bd20 (console_owner){-.-.}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:331 [inline]
ffffffff8465bd20 (console_owner){-.-.}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:267 [inline]
ffffffff8465bd20 (console_owner){-.-.}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:286 [inline]
ffffffff8465bd20 (console_owner){-.-.}-{0:0}, at: console_flush_all+0x14d/0xd10 kernel/printk/printk.c:3041

but task is already holding lock:
ffff8881f713b1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:579 [inline]
ffff8881f713b1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1419 [inline]
ffff8881f713b1d8 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1718 [inline]
ffff8881f713b1d8 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x31a/0x2510 kernel/sched/core.c:6474

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:5759
       _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
       raw_spin_rq_lock_nested kernel/sched/core.c:579 [inline]
       raw_spin_rq_lock kernel/sched/sched.h:1419 [inline]
       __task_rq_lock+0xdc/0x300 kernel/sched/core.c:657
       wake_up_new_task+0x52b/0x9f0 kernel/sched/core.c:4716
       kernel_clone+0x384/0x6b0 kernel/fork.c:2812
       user_mode_thread+0x12d/0x190 kernel/fork.c:2859
       rest_init+0x1c/0x250 init/main.c:712
       start_kernel+0x305/0x370 init/main.c:1103
       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+0x12c/0x137

-> #3 (&p->pi_lock){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       __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+0xa8/0x1050 kernel/sched/core.c:4082
       __wake_up_common kernel/sched/wait.c:89 [inline]
       __wake_up_common_lock+0x130/0x1e0 kernel/sched/wait.c:106
       tty_port_default_wakeup+0x85/0xc0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x21e/0x780 drivers/tty/serial/8250/8250_port.c:1821
       serial8250_handle_irq+0x3d6/0x570 drivers/tty/serial/8250/8250_port.c:1929
       serial8250_default_handle_irq+0x9a/0x170 drivers/tty/serial/8250/8250_port.c:1949
       serial8250_interrupt+0xa2/0x180 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x23f/0x7b0 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x83/0x1c0 kernel/irq/handle.c:210
       handle_edge_irq+0x21c/0x9f0 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+0xda/0x1b0 arch/x86/kernel/irq.c:285
       common_interrupt+0xa0/0xc0 arch/x86/kernel/irq.c:278
       asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
       seqcount_lockdep_reader_access+0x184/0x1e0 include/linux/seqlock.h:75
       nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:345 [inline]
       gc_worker+0x2b6/0x10f0 net/netfilter/nf_conntrack_core.c:1488
       process_one_work kernel/workqueue.c:3231 [inline]
       process_scheduled_works+0x953/0x1500 kernel/workqueue.c:3312
       worker_thread+0x748/0xb40 kernel/workqueue.c:3390
       kthread+0x2e0/0x380 kernel/kthread.c:389
       ret_from_fork+0x32/0x60 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #2 (&tty->write_wait){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       __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+0x85/0xc0 drivers/tty/tty_port.c:69
       serial8250_tx_chars+0x21e/0x780 drivers/tty/serial/8250/8250_port.c:1821
       serial8250_handle_irq+0x3d6/0x570 drivers/tty/serial/8250/8250_port.c:1929
       serial8250_default_handle_irq+0x9a/0x170 drivers/tty/serial/8250/8250_port.c:1949
       serial8250_interrupt+0xa2/0x180 drivers/tty/serial/8250/8250_core.c:86
       __handle_irq_event_percpu+0x23f/0x7b0 kernel/irq/handle.c:158
       handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
       handle_irq_event+0x83/0x1c0 kernel/irq/handle.c:210
       handle_edge_irq+0x21c/0x9f0 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+0xda/0x1b0 arch/x86/kernel/irq.c:285
       common_interrupt+0xa0/0xc0 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:152 [inline]
       _raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
       spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
       uart_port_unlock_irqrestore include/linux/serial_core.h:669 [inline]
       uart_write+0x10f/0x2a0 drivers/tty/serial/serial_core.c:634
       process_output_block drivers/tty/n_tty.c:574 [inline]
       n_tty_write+0xe6c/0x1250 drivers/tty/n_tty.c:2389
       iterate_tty_write drivers/tty/tty_io.c:1021 [inline]
       file_tty_write+0x489/0x810 drivers/tty/tty_io.c:1096
       new_sync_write fs/read_write.c:497 [inline]
       vfs_write+0x63a/0xc30 fs/read_write.c:590
       ksys_write+0x163/0x250 fs/read_write.c:643
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x210 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&port_lock_key){-.-.}-{2:2}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       __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:618 [inline]
       serial8250_console_write+0x175/0x15e0 drivers/tty/serial/8250/8250_port.c:3352
       console_emit_next_record kernel/printk/printk.c:2983 [inline]
       console_flush_all+0x686/0xd10 kernel/printk/printk.c:3049
       console_unlock+0x136/0x420 kernel/printk/printk.c:3118
       vprintk_emit+0x3ef/0x5f0 kernel/printk/printk.c:2348
       _printk+0xce/0x120 kernel/printk/printk.c:2373
       register_console+0x6b0/0x9c0 kernel/printk/printk.c:3654
       univ8250_console_init+0x3a/0x70 drivers/tty/serial/8250/8250_core.c:513
       console_init+0x11c/0x450 kernel/printk/printk.c:3800
       start_kernel+0x249/0x370 init/main.c:1038
       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+0x12c/0x137

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3133 [inline]
       check_prevs_add kernel/locking/lockdep.c:3252 [inline]
       validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
       __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
       console_lock_spinning_enable kernel/printk/printk.c:1873 [inline]
       console_emit_next_record kernel/printk/printk.c:2977 [inline]
       console_flush_all+0x635/0xd10 kernel/printk/printk.c:3049
       console_unlock+0x136/0x420 kernel/printk/printk.c:3118
       vprintk_emit+0x3ef/0x5f0 kernel/printk/printk.c:2348
       _printk+0xce/0x120 kernel/printk/printk.c:2373
       __report_bug lib/bug.c:195 [inline]
       report_bug+0x268/0x420 lib/bug.c:219
       handle_bug+0x3e/0x70 arch/x86/kernel/traps.c:239
       exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:260
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
       lockdep_assert_rq_held kernel/sched/sched.h:1410 [inline]
       rq_clock kernel/sched/sched.h:1558 [inline]
       replenish_dl_new_period kernel/sched/deadline.c:777 [inline]
       update_curr_dl_se+0x644/0x8d0 kernel/sched/deadline.c:1511
       update_curr+0x494/0x6b0 kernel/sched/fair.c:1176
       put_prev_entity kernel/sched/fair.c:5505 [inline]
       put_prev_task_fair+0x7f/0x1c0 kernel/sched/fair.c:8684
       put_prev_task kernel/sched/sched.h:2352 [inline]
       put_prev_task_balance kernel/sched/core.c:5822 [inline]
       __pick_next_task kernel/sched/core.c:5879 [inline]
       pick_next_task kernel/sched/core.c:6374 [inline]
       __schedule+0x8bf/0x2510 kernel/sched/core.c:6522
       preempt_schedule_common kernel/sched/core.c:6746 [inline]
       __cond_resched+0x99/0xe0 kernel/sched/core.c:7079
       _cond_resched include/linux/sched.h:2022 [inline]
       count_strings_kernel fs/exec.c:484 [inline]
       kernel_execve+0x19f/0x830 fs/exec.c:2052
       call_usermodehelper_exec_async+0x204/0x320 kernel/umh.c:110
       ret_from_fork+0x32/0x60 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 ***

3 locks held by kworker/u8:5/4337:
 #0: ffff8881f713b1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:579 [inline]
 #0: ffff8881f713b1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1419 [inline]
 #0: ffff8881f713b1d8 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1718 [inline]
 #0: ffff8881f713b1d8 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x31a/0x2510 kernel/sched/core.c:6474
 #1: ffffffff84543640 (console_lock){+.+.}-{0:0}, at: _printk+0xce/0x120 kernel/printk/printk.c:2373
 #2: ffffffff84543270 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff84543270 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:267 [inline]
 #2: ffffffff84543270 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:286 [inline]
 #2: ffffffff84543270 (console_srcu){....}-{0:0}, at: console_flush_all+0x14d/0xd10 kernel/printk/printk.c:3041

stack backtrace:
CPU: 1 UID: 0 PID: 4337 Comm: kworker/u8:5 Not tainted 6.11.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x198/0x250 lib/dump_stack.c:119
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186
 check_prev_add kernel/locking/lockdep.c:3133 [inline]
 check_prevs_add kernel/locking/lockdep.c:3252 [inline]
 validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
 console_lock_spinning_enable kernel/printk/printk.c:1873 [inline]
 console_emit_next_record kernel/printk/printk.c:2977 [inline]
 console_flush_all+0x635/0xd10 kernel/printk/printk.c:3049
 console_unlock+0x136/0x420 kernel/printk/printk.c:3118
 vprintk_emit+0x3ef/0x5f0 kernel/printk/printk.c:2348
 _printk+0xce/0x120 kernel/printk/printk.c:2373
 __report_bug lib/bug.c:195 [inline]
 report_bug+0x268/0x420 lib/bug.c:219
 handle_bug+0x3e/0x70 arch/x86/kernel/traps.c:239
 exc_invalid_op+0x1a/0x50 arch/x86/kernel/traps.c:260
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1410 [inline]
RIP: 0010:rq_clock kernel/sched/sched.h:1558 [inline]
RIP: 0010:replenish_dl_new_period kernel/sched/deadline.c:777 [inline]
RIP: 0010:update_curr_dl_se+0x644/0x8d0 kernel/sched/deadline.c:1511
Code: 24 50 fe ff ff 4c 89 ff ba 20 00 00 00 e8 d4 45 00 00 e9 56 fe ff ff 4c 89 e7 be 20 00 00 00 e8 72 12 00 00 e9 44 fe ff ff 90 <0f> 0b 90 e9 ab fb ff ff 89 f1 80 e1 07 38 c1 0f 8c e0 f9 ff ff 48
RSP: 0018:ffffc9000301fb98 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8881f703b1c0 RCX: 0000000000000003
RDX: dffffc0000000000 RSI: ffffffff83a677c0 RDI: ffffffff83bc8900
RBP: 0000000000000031 R08: ffff8881f702c4c3 R09: 1ffff1103ee05898
R10: dffffc0000000000 R11: ffffed103ee05899 R12: ffff8881f703bb28
R13: ffff8881f703bb68 R14: 1ffff1103ee0776f R15: dffffc0000000000
 update_curr+0x494/0x6b0 kernel/sched/fair.c:1176
 put_prev_entity kernel/sched/fair.c:5505 [inline]
 put_prev_task_fair+0x7f/0x1c0 kernel/sched/fair.c:8684
 put_prev_task kernel/sched/sched.h:2352 [inline]
 put_prev_task_balance kernel/sched/core.c:5822 [inline]
 __pick_next_task kernel/sched/core.c:5879 [inline]
 pick_next_task kernel/sched/core.c:6374 [inline]
 __schedule+0x8bf/0x2510 kernel/sched/core.c:6522
 preempt_schedule_common kernel/sched/core.c:6746 [inline]
 __cond_resched+0x99/0xe0 kernel/sched/core.c:7079
 _cond_resched include/linux/sched.h:2022 [inline]
 count_strings_kernel fs/exec.c:484 [inline]
 kernel_execve+0x19f/0x830 fs/exec.c:2052
 call_usermodehelper_exec_async+0x204/0x320 kernel/umh.c:110
 ret_from_fork+0x32/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
WARNING: CPU: 1 PID: 4337 at kernel/sched/sched.h:1410 lockdep_assert_rq_held kernel/sched/sched.h:1410 [inline]
WARNING: CPU: 1 PID: 4337 at kernel/sched/sched.h:1410 rq_clock kernel/sched/sched.h:1558 [inline]
WARNING: CPU: 1 PID: 4337 at kernel/sched/sched.h:1410 replenish_dl_new_period kernel/sched/deadline.c:777 [inline]
WARNING: CPU: 1 PID: 4337 at kernel/sched/sched.h:1410 update_curr_dl_se+0x644/0x8d0 kernel/sched/deadline.c:1511
Modules linked in:
CPU: 1 UID: 0 PID: 4337 Comm: kworker/u8:5 Not tainted 6.11.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1410 [inline]
RIP: 0010:rq_clock kernel/sched/sched.h:1558 [inline]
RIP: 0010:replenish_dl_new_period kernel/sched/deadline.c:777 [inline]
RIP: 0010:update_curr_dl_se+0x644/0x8d0 kernel/sched/deadline.c:1511
Code: 24 50 fe ff ff 4c 89 ff ba 20 00 00 00 e8 d4 45 00 00 e9 56 fe ff ff 4c 89 e7 be 20 00 00 00 e8 72 12 00 00 e9 44 fe ff ff 90 <0f> 0b 90 e9 ab fb ff ff 89 f1 80 e1 07 38 c1 0f 8c e0 f9 ff ff 48
RSP: 0018:ffffc9000301fb98 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8881f703b1c0 RCX: 0000000000000003
RDX: dffffc0000000000 RSI: ffffffff83a677c0 RDI: ffffffff83bc8900
RBP: 0000000000000031 R08: ffff8881f702c4c3 R09: 1ffff1103ee05898
R10: dffffc0000000000 R11: ffffed103ee05899 R12: ffff8881f703bb28
R13: ffff8881f703bb68 R14: 1ffff1103ee0776f R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa3725d3380 CR3: 00000001205c4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 update_curr+0x494/0x6b0 kernel/sched/fair.c:1176
 put_prev_entity kernel/sched/fair.c:5505 [inline]
 put_prev_task_fair+0x7f/0x1c0 kernel/sched/fair.c:8684
 put_prev_task kernel/sched/sched.h:2352 [inline]
 put_prev_task_balance kernel/sched/core.c:5822 [inline]
 __pick_next_task kernel/sched/core.c:5879 [inline]
 pick_next_task kernel/sched/core.c:6374 [inline]
 __schedule+0x8bf/0x2510 kernel/sched/core.c:6522
 preempt_schedule_common kernel/sched/core.c:6746 [inline]
 __cond_resched+0x99/0xe0 kernel/sched/core.c:7079
 _cond_resched include/linux/sched.h:2022 [inline]
 count_strings_kernel fs/exec.c:484 [inline]
 kernel_execve+0x19f/0x830 fs/exec.c:2052
 call_usermodehelper_exec_async+0x204/0x320 kernel/umh.c:110
 ret_from_fork+0x32/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>