===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 Tainted: G U ----------------------------------------------------- kworker/u8:8/6845 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff8f344058 (disc_data_lock#2){.+.+}-{3:3}, at: sp_get+0x18/0xf0 drivers/net/hamradio/6pack.c:370 and this task is already holding: ffffffff9aad5578 (&port_lock_key){-.-.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:715 [inline] ffffffff9aad5578 (&port_lock_key){-.-.}-{3:3}, at: uart_write+0x13b/0xb30 drivers/tty/serial/serial_core.c:626 which would create a new lock dependency: (&port_lock_key){-.-.}-{3:3} -> (disc_data_lock#2){.+.+}-{3:3} but this new dependency connects a HARDIRQ-irq-safe lock: (&port_lock_key){-.-.}-{3:3} ... which became HARDIRQ-irq-safe at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __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:715 [inline] serial8250_handle_irq+0x95/0xc80 drivers/tty/serial/8250/8250_port.c:1923 serial8250_default_handle_irq+0x9a/0x210 drivers/tty/serial/8250/8250_port.c:1972 serial8250_interrupt+0x103/0x210 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x229/0x7d0 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+0xdf/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:699 cpuidle_enter_state+0xaa/0x4f0 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:389 cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x310/0x3f0 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:743 start_kernel+0x3e9/0x4d0 init/main.c:1099 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:515 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:496 common_startup_64+0x13e/0x148 to a HARDIRQ-irq-unsafe lock: (disc_data_lock#2){.+.+}-{3:3} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 sp_get+0x18/0xf0 drivers/net/hamradio/6pack.c:370 sixpack_receive_buf drivers/net/hamradio/6pack.c:433 [inline] sixpack_receive_buf+0x59/0x1c80 drivers/net/hamradio/6pack.c:424 tty_ldisc_receive_buf+0x153/0x190 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(disc_data_lock#2); local_irq_disable(); lock(&port_lock_key); lock(disc_data_lock#2); lock(&port_lock_key); *** DEADLOCK *** 6 locks held by kworker/u8:8/6845: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3211 #1: ffffc900192bfd18 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3212 #2: ffff8880252308a8 (&buf->lock){+.+.}-{4:4}, at: flush_to_ldisc+0x31/0x780 drivers/tty/tty_buffer.c:467 #3: ffff888030ea10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x80 drivers/tty/tty_ldisc.c:263 #4: ffffffff9aad5578 (&port_lock_key){-.-.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:715 [inline] #4: ffffffff9aad5578 (&port_lock_key){-.-.}-{3:3}, at: uart_write+0x13b/0xb30 drivers/tty/serial/serial_core.c:626 #5: ffff888030ea10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x80 drivers/tty/tty_ldisc.c:263 the dependencies between HARDIRQ-irq-safe lock and the holding lock: -> (&port_lock_key){-.-.}-{3:3} { IN-HARDIRQ-W at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __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:715 [inline] serial8250_handle_irq+0x95/0xc80 drivers/tty/serial/8250/8250_port.c:1923 serial8250_default_handle_irq+0x9a/0x210 drivers/tty/serial/8250/8250_port.c:1972 serial8250_interrupt+0x103/0x210 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x229/0x7d0 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+0xdf/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:699 cpuidle_enter_state+0xaa/0x4f0 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:389 cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x310/0x3f0 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:743 start_kernel+0x3e9/0x4d0 init/main.c:1099 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:515 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:496 common_startup_64+0x13e/0x148 IN-SOFTIRQ-W at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __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:715 [inline] serial8250_console_write+0x17c/0x1870 drivers/tty/serial/8250/8250_port.c:3415 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x800/0xc60 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 wake_up_klogd_work_func+0xcf/0x110 kernel/printk/printk.c:4492 irq_work_single+0x1bc/0x260 kernel/irq_work.c:221 irq_work_run_list+0x92/0xc0 kernel/irq_work.c:252 update_process_times+0x1d4/0x2d0 kernel/time/timer.c:2518 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x376/0x530 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x5fb/0xae0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 queue_work_on+0x98/0x140 kernel/workqueue.c:2394 __ieee80211_queue_skb_to_iface net/mac80211/rx.c:233 [inline] ieee80211_queue_skb_to_iface net/mac80211/rx.c:244 [inline] ieee80211_rx_h_mgmt net/mac80211/rx.c:4069 [inline] ieee80211_rx_handlers+0x6d14/0xc5b0 net/mac80211/rx.c:4227 ieee80211_invoke_rx_handlers net/mac80211/rx.c:4257 [inline] ieee80211_prepare_and_rx_handle+0x2dbc/0x7180 net/mac80211/rx.c:5107 ieee80211_rx_for_interface+0x10a/0x1f0 net/mac80211/rx.c:5192 __ieee80211_rx_handle_packet net/mac80211/rx.c:5348 [inline] ieee80211_rx_list+0x108e/0x2990 net/mac80211/rx.c:5483 ieee80211_rx_napi+0xdd/0x400 net/mac80211/rx.c:5506 ieee80211_rx include/net/mac80211.h:5172 [inline] ieee80211_handle_queued_frames+0xd5/0x130 net/mac80211/main.c:441 tasklet_action_common+0x251/0x3f0 kernel/softirq.c:811 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 kasan_mem_to_shadow include/linux/kasan.h:65 [inline] memory_is_poisoned_n mm/kasan/generic.c:129 [inline] memory_is_poisoned mm/kasan/generic.c:161 [inline] check_region_inline mm/kasan/generic.c:180 [inline] kasan_check_range+0x5a/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_add_negative include/linux/atomic/atomic-instrumented.h:1420 [inline] __folio_remove_rmap mm/rmap.c:1547 [inline] folio_remove_rmap_ptes+0x94/0x3c0 mm/rmap.c:1620 zap_present_folio_ptes mm/memory.c:1535 [inline] zap_present_ptes mm/memory.c:1596 [inline] do_zap_pte_range mm/memory.c:1698 [inline] zap_pte_range mm/memory.c:1740 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x1b1d/0x4350 mm/memory.c:1894 unmap_single_vma+0x194/0x2b0 mm/memory.c:1940 unmap_vmas+0x22f/0x490 mm/memory.c:1984 exit_mmap+0x1c1/0xba0 mm/mmap.c:1284 __mmput+0x12a/0x410 kernel/fork.c:1356 mmput+0x62/0x70 kernel/fork.c:1378 exit_mm kernel/exit.c:570 [inline] do_exit+0x9ba/0x2d70 kernel/exit.c:925 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232 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 INITIAL USE at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __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:715 [inline] serial8250_do_set_termios+0x307/0x16f0 drivers/tty/serial/8250/8250_port.c:2774 serial8250_set_termios+0x6e/0x80 drivers/tty/serial/8250/8250_port.c:2899 uart_set_options+0x31b/0x5f0 drivers/tty/serial/serial_core.c:2311 serial8250_console_setup+0x18a/0x460 drivers/tty/serial/8250/8250_port.c:3519 univ8250_console_setup+0x1d4/0x2c0 drivers/tty/serial/8250/8250_core.c:428 console_call_setup kernel/printk/printk.c:3773 [inline] console_call_setup kernel/printk/printk.c:3764 [inline] try_enable_preferred_console+0x2fd/0x530 kernel/printk/printk.c:3817 register_console+0x3ac/0x1170 kernel/printk/printk.c:4011 univ8250_console_init+0x5f/0x90 drivers/tty/serial/8250/8250_core.c:513 console_init+0x154/0x690 kernel/printk/printk.c:4292 start_kernel+0x29f/0x4d0 init/main.c:1034 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:515 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:496 common_startup_64+0x13e/0x148 } ... key at: [] port_lock_key+0x0/0x40 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (disc_data_lock#2){.+.+}-{3:3} { HARDIRQ-ON-R at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 sp_get+0x18/0xf0 drivers/net/hamradio/6pack.c:370 sixpack_receive_buf drivers/net/hamradio/6pack.c:433 [inline] sixpack_receive_buf+0x59/0x1c80 drivers/net/hamradio/6pack.c:424 tty_ldisc_receive_buf+0x153/0x190 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 SOFTIRQ-ON-R at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 sp_get+0x18/0xf0 drivers/net/hamradio/6pack.c:370 sixpack_receive_buf drivers/net/hamradio/6pack.c:433 [inline] sixpack_receive_buf+0x59/0x1c80 drivers/net/hamradio/6pack.c:424 tty_ldisc_receive_buf+0x153/0x190 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INITIAL USE at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326 sixpack_close+0x1e/0x2f0 drivers/net/hamradio/6pack.c:641 tty_ldisc_close+0x111/0x1a0 drivers/tty/tty_ldisc.c:455 tty_ldisc_kill+0x8e/0x150 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x116/0x2a0 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x23/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xe25/0x1410 drivers/tty/tty_io.c:1861 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xad8/0x2d70 kernel/exit.c:938 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087 get_signal+0x2576/0x2610 kernel/signal.c:3036 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 sp_get+0x18/0xf0 drivers/net/hamradio/6pack.c:370 sixpack_receive_buf drivers/net/hamradio/6pack.c:433 [inline] sixpack_receive_buf+0x59/0x1c80 drivers/net/hamradio/6pack.c:424 tty_ldisc_receive_buf+0x153/0x190 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 } ... key at: [] disc_data_lock+0x18/0x1020 ... acquired at: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 sp_get+0x18/0xf0 drivers/net/hamradio/6pack.c:370 sixpack_write_wakeup+0x20/0x390 drivers/net/hamradio/6pack.c:391 tty_wakeup+0xe5/0x120 drivers/tty/tty_io.c:517 tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1844 __start_tx+0x3e9/0x4a0 drivers/tty/serial/8250/8250_port.c:1549 serial8250_start_tx+0x368/0x530 drivers/tty/serial/8250/8250_port.c:1659 __uart_start+0x292/0x4c0 drivers/tty/serial/serial_core.c:160 uart_write+0x218/0xb30 drivers/tty/serial/serial_core.c:635 decode_prio_command drivers/net/hamradio/6pack.c:868 [inline] sixpack_decode drivers/net/hamradio/6pack.c:943 [inline] sixpack_receive_buf drivers/net/hamradio/6pack.c:447 [inline] sixpack_receive_buf+0x3d7/0x1c80 drivers/net/hamradio/6pack.c:424 tty_ldisc_receive_buf+0x153/0x190 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 stack backtrace: CPU: 0 UID: 0 PID: 6845 Comm: kworker/u8:8 Tainted: G U 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound flush_to_ldisc Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_bad_irq_dependency kernel/locking/lockdep.c:2649 [inline] check_irq_usage+0xf22/0x1290 kernel/locking/lockdep.c:2890 check_prev_add kernel/locking/lockdep.c:3167 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x24b4/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228 sp_get+0x18/0xf0 drivers/net/hamradio/6pack.c:370 sixpack_write_wakeup+0x20/0x390 drivers/net/hamradio/6pack.c:391 tty_wakeup+0xe5/0x120 drivers/tty/tty_io.c:517 tty_port_default_wakeup+0x2a/0x40 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x68e/0x860 drivers/tty/serial/8250/8250_port.c:1844 __start_tx+0x3e9/0x4a0 drivers/tty/serial/8250/8250_port.c:1549 serial8250_start_tx+0x368/0x530 drivers/tty/serial/8250/8250_port.c:1659 __uart_start+0x292/0x4c0 drivers/tty/serial/serial_core.c:160 uart_write+0x218/0xb30 drivers/tty/serial/serial_core.c:635 decode_prio_command drivers/net/hamradio/6pack.c:868 [inline] sixpack_decode drivers/net/hamradio/6pack.c:943 [inline] sixpack_receive_buf drivers/net/hamradio/6pack.c:447 [inline] sixpack_receive_buf+0x3d7/0x1c80 drivers/net/hamradio/6pack.c:424 tty_ldisc_receive_buf+0x153/0x190 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x70/0xb0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x264/0x780 drivers/tty/tty_buffer.c:495 process_one_work+0x958/0x1b30 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244