------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc4-next-20240823-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.27/5416 is trying to acquire lock:
ffffffff8e815120 (console_owner){-.-.}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:2024 [inline]
ffffffff8e815120 (console_owner){-.-.}-{0:0}, at: vprintk_emit+0x602/0xa10 kernel/printk/printk.c:2398

but task is already holding lock:
ffff8880b903ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:595

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:587
       raw_spin_rq_lock kernel/sched/sched.h:1488 [inline]
       task_rq_lock+0xc6/0x360 kernel/sched/core.c:689
       cgroup_move_task+0x92/0x2d0 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:6690
       copy_process+0x39e9/0x3d50 kernel/fork.c:2598
       kernel_clone+0x226/0x8f0 kernel/fork.c:2784
       user_mode_thread+0x132/0x1a0 kernel/fork.c:2862
       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+0xb0/0x1480 kernel/sched/core.c:4150
       __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+0x112/0x480 drivers/cpuidle/cpuidle.c:267
       cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388
       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
       start_secondary+0x102/0x110 arch/x86/kernel/smpboot.c:313
       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+0x112/0x480 drivers/cpuidle/cpuidle.c:267
       cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:388
       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
       start_secondary+0x102/0x110 arch/x86/kernel/smpboot.c:313
       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:3010 [inline]
       console_flush_all+0x882/0xf50 kernel/printk/printk.c:3082
       console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3153
       vprintk_emit+0x87d/0xa10 kernel/printk/printk.c:2399
       _printk+0xd5/0x120 kernel/printk/printk.c:2424
       register_console+0xbf5/0xfd0 kernel/printk/printk.c:3737
       univ8250_console_init+0x52/0x90 drivers/tty/serial/8250/8250_core.c:513
       console_init+0x1b8/0x6f0 kernel/printk/printk.c:3919
       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_trylock_spinning kernel/printk/printk.c:2024 [inline]
       vprintk_emit+0x61f/0xa10 kernel/printk/printk.c:2398
       _printk+0xd5/0x120 kernel/printk/printk.c:2424
       __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
       dequeue_top_rt_rq kernel/sched/rt.c:1035 [inline]
       dequeue_rt_stack+0xb93/0xbc0 kernel/sched/rt.c:1434
       dequeue_rt_entity kernel/sched/rt.c:1455 [inline]
       dequeue_task_rt+0x12a/0x740 kernel/sched/rt.c:1491
       block_task kernel/sched/core.c:2079 [inline]
       __schedule+0x5d9/0x4b30 kernel/sched/core.c:6627
       __schedule_loop kernel/sched/core.c:6754 [inline]
       schedule+0x14b/0x320 kernel/sched/core.c:6769
       futex_wait_queue+0x14e/0x1d0 kernel/futex/waitwake.c:370
       __futex_wait+0x17f/0x320 kernel/futex/waitwake.c:669
       futex_wait+0x101/0x360 kernel/futex/waitwake.c:697
       do_futex+0x33b/0x560 kernel/futex/syscalls.c:102
       __do_sys_futex kernel/futex/syscalls.c:179 [inline]
       __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

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 ***

1 lock held by syz.0.27/5416:
 #0: ffff8880b903ea58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:595

stack backtrace:
CPU: 1 UID: 0 PID: 5416 Comm: syz.0.27 Not tainted 6.11.0-rc4-next-20240823-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: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_trylock_spinning kernel/printk/printk.c:2024 [inline]
 vprintk_emit+0x61f/0xa10 kernel/printk/printk.c:2398
 _printk+0xd5/0x120 kernel/printk/printk.c:2424
 __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:dequeue_top_rt_rq kernel/sched/rt.c:1035 [inline]
RIP: 0010:dequeue_rt_stack+0xb93/0xbc0 kernel/sched/rt.c:1434
Code: 00 00 00 fc ff df e9 0d f5 ff ff 48 c7 c7 80 e0 7f 8e 48 89 de e8 ad ca 83 03 48 ba 00 00 00 00 00 fc ff df e9 fb fd ff ff 90 <0f> 0b f3 0f 1e fa 8b 74 24 10 f7 de 4c 89 f7 e8 59 93 f8 ff 48 ba
RSP: 0018:ffffc900048e7730 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff816d583b
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff888140ac21d0
RBP: 1ffff11017227d50 R08: ffff888140ac21d7 R09: 1ffff1102815843a
R10: dffffc0000000000 R11: ffffed102815843b R12: ffff8880b913ea80
R13: 1ffff11017227e77 R14: ffff8880b913ea40 R15: ffff8880b913f3b8
 dequeue_rt_entity kernel/sched/rt.c:1455 [inline]
 dequeue_task_rt+0x12a/0x740 kernel/sched/rt.c:1491
 block_task kernel/sched/core.c:2079 [inline]
 __schedule+0x5d9/0x4b30 kernel/sched/core.c:6627
 __schedule_loop kernel/sched/core.c:6754 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6769
 futex_wait_queue+0x14e/0x1d0 kernel/futex/waitwake.c:370
 __futex_wait+0x17f/0x320 kernel/futex/waitwake.c:669
 futex_wait+0x101/0x360 kernel/futex/waitwake.c:697
 do_futex+0x33b/0x560 kernel/futex/syscalls.c:102
 __do_sys_futex kernel/futex/syscalls.c:179 [inline]
 __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb669579e79
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:00007ffcf94c0478 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 0000000000015166 RCX: 00007fb669579e79
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb669715f8c
RBP: 00007fb669715f8c R08: 00007fb669715f80 R09: 00007ffcf94c075f
R10: 00007ffcf94c0570 R11: 0000000000000246 R12: 0000000000000032
R13: 00007ffcf94c0570 R14: 00007ffcf94c0590 R15: 0000000000015134
 </TASK>
kernel BUG at kernel/sched/rt.c:1035!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5416 Comm: syz.0.27 Not tainted 6.11.0-rc4-next-20240823-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:dequeue_top_rt_rq kernel/sched/rt.c:1035 [inline]
RIP: 0010:dequeue_rt_stack+0xb93/0xbc0 kernel/sched/rt.c:1434
Code: 00 00 00 fc ff df e9 0d f5 ff ff 48 c7 c7 80 e0 7f 8e 48 89 de e8 ad ca 83 03 48 ba 00 00 00 00 00 fc ff df e9 fb fd ff ff 90 <0f> 0b f3 0f 1e fa 8b 74 24 10 f7 de 4c 89 f7 e8 59 93 f8 ff 48 ba
RSP: 0018:ffffc900048e7730 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff816d583b
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff888140ac21d0
RBP: 1ffff11017227d50 R08: ffff888140ac21d7 R09: 1ffff1102815843a
R10: dffffc0000000000 R11: ffffed102815843b R12: ffff8880b913ea80
R13: 1ffff11017227e77 R14: ffff8880b913ea40 R15: ffff8880b913f3b8
FS:  000055558916b500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2ef25d CR3: 0000000061f5e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dequeue_rt_entity kernel/sched/rt.c:1455 [inline]
 dequeue_task_rt+0x12a/0x740 kernel/sched/rt.c:1491
 block_task kernel/sched/core.c:2079 [inline]
 __schedule+0x5d9/0x4b30 kernel/sched/core.c:6627
 __schedule_loop kernel/sched/core.c:6754 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6769
 futex_wait_queue+0x14e/0x1d0 kernel/futex/waitwake.c:370
 __futex_wait+0x17f/0x320 kernel/futex/waitwake.c:669
 futex_wait+0x101/0x360 kernel/futex/waitwake.c:697
 do_futex+0x33b/0x560 kernel/futex/syscalls.c:102
 __do_sys_futex kernel/futex/syscalls.c:179 [inline]
 __se_sys_futex+0x3f9/0x480 kernel/futex/syscalls.c:160
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb669579e79
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:00007ffcf94c0478 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 0000000000015166 RCX: 00007fb669579e79
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb669715f8c
RBP: 00007fb669715f8c R08: 00007fb669715f80 R09: 00007ffcf94c075f
R10: 00007ffcf94c0570 R11: 0000000000000246 R12: 0000000000000032
R13: 00007ffcf94c0570 R14: 00007ffcf94c0590 R15: 0000000000015134
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dequeue_top_rt_rq kernel/sched/rt.c:1035 [inline]
RIP: 0010:dequeue_rt_stack+0xb93/0xbc0 kernel/sched/rt.c:1434
Code: 00 00 00 fc ff df e9 0d f5 ff ff 48 c7 c7 80 e0 7f 8e 48 89 de e8 ad ca 83 03 48 ba 00 00 00 00 00 fc ff df e9 fb fd ff ff 90 <0f> 0b f3 0f 1e fa 8b 74 24 10 f7 de 4c 89 f7 e8 59 93 f8 ff 48 ba
RSP: 0018:ffffc900048e7730 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff816d583b
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff888140ac21d0
RBP: 1ffff11017227d50 R08: ffff888140ac21d7 R09: 1ffff1102815843a
R10: dffffc0000000000 R11: ffffed102815843b R12: ffff8880b913ea80
R13: 1ffff11017227e77 R14: ffff8880b913ea40 R15: ffff8880b913f3b8
FS:  000055558916b500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2ef25d CR3: 0000000061f5e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400