===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 Not tainted ----------------------------------------------------- kworker/u8:39/11417 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff8f4a7e18 (disc_data_lock){.+.+}-{3:3}, at: sp_get drivers/net/hamradio/6pack.c:370 [inline] ffffffff8f4a7e18 (disc_data_lock){.+.+}-{3:3}, at: sixpack_write_wakeup+0x30/0x440 drivers/net/hamradio/6pack.c:391 and this task is already holding: ffffffff9a713958 (&port_lock_key){-.-.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:715 [inline] ffffffff9a713958 (&port_lock_key){-.-.}-{3:3}, at: uart_write+0x107/0xa40 drivers/tty/serial/serial_core.c:626 which would create a new lock dependency: (&port_lock_key){-.-.}-{3:3} -> (disc_data_lock){.+.+}-{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+0x1ed/0x550 kernel/locking/lockdep.c:5851 __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:715 [inline] serial8250_handle_irq+0x6d/0xb80 drivers/tty/serial/8250/8250_port.c:1923 serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1972 serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x29a/0xa60 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:699 cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:389 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x372/0x5c0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 rest_init+0x2dc/0x300 init/main.c:743 start_kernel+0x484/0x510 init/main.c:1099 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:496 common_startup_64+0x13e/0x147 to a HARDIRQ-irq-unsafe lock: (disc_data_lock){.+.+}-{3:3} ... which became HARDIRQ-irq-unsafe at: ... lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 sp_get drivers/net/hamradio/6pack.c:370 [inline] sixpack_ioctl+0x81/0x550 drivers/net/hamradio/6pack.c:676 tty_ioctl+0x998/0xdc0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 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: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(disc_data_lock); local_irq_disable(); lock(&port_lock_key); lock(disc_data_lock); lock(&port_lock_key); *** DEADLOCK *** 6 locks held by kworker/u8:39/11417: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9001037fc60 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9001037fc60 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffff888024cc0ca0 (&buf->lock){+.+.}-{4:4}, at: flush_to_ldisc+0x38/0x860 drivers/tty/tty_buffer.c:467 #3: ffff8880618fc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1c/0x80 drivers/tty/tty_ldisc.c:263 #4: ffffffff9a713958 (&port_lock_key){-.-.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:715 [inline] #4: ffffffff9a713958 (&port_lock_key){-.-.}-{3:3}, at: uart_write+0x107/0xa40 drivers/tty/serial/serial_core.c:626 #5: ffff8880618fc0a0 (&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+0x1ed/0x550 kernel/locking/lockdep.c:5851 __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:715 [inline] serial8250_handle_irq+0x6d/0xb80 drivers/tty/serial/8250/8250_port.c:1923 serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1972 serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x29a/0xa60 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:699 cpuidle_enter_state+0x109/0x470 drivers/cpuidle/cpuidle.c:268 cpuidle_enter+0x5d/0xa0 drivers/cpuidle/cpuidle.c:389 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x372/0x5c0 kernel/sched/idle.c:325 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423 rest_init+0x2dc/0x300 init/main.c:743 start_kernel+0x484/0x510 init/main.c:1099 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:496 common_startup_64+0x13e/0x147 IN-SOFTIRQ-W at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __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:715 [inline] serial8250_handle_irq+0x6d/0xb80 drivers/tty/serial/8250/8250_port.c:1923 serial8250_default_handle_irq+0xd1/0x1f0 drivers/tty/serial/8250/8250_port.c:1972 serial8250_interrupt+0xa9/0x1f0 drivers/tty/serial/8250/8250_core.c:86 __handle_irq_event_percpu+0x29a/0xa60 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+0x5e/0xd0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 arch_local_irq_enable arch/x86/include/asm/irqflags.h:97 [inline] handle_softirqs+0x1ef/0x9b0 kernel/softirq.c:545 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 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+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 native_irq_enable arch/x86/include/asm/irqflags.h:42 [inline] arch_local_irq_enable arch/x86/include/asm/irqflags.h:97 [inline] raw_spin_rq_unlock_irq kernel/sched/sched.h:1533 [inline] finish_lock_switch kernel/sched/core.c:5131 [inline] finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5249 schedule_tail+0xf/0xb0 kernel/sched/core.c:5308 ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 INITIAL USE at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __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:715 [inline] serial8250_do_set_termios+0x4da/0x1c70 drivers/tty/serial/8250/8250_port.c:2774 uart_set_options+0x3eb/0x730 drivers/tty/serial/serial_core.c:2311 serial8250_console_setup+0x3db/0x670 drivers/tty/serial/8250/8250_port.c:3519 univ8250_console_setup+0x426/0x530 drivers/tty/serial/8250/8250_core.c:428 console_call_setup kernel/printk/printk.c:3773 [inline] try_enable_preferred_console+0x46b/0x5c0 kernel/printk/printk.c:3817 register_console+0x37a/0xfd0 kernel/printk/printk.c:4011 univ8250_console_init+0x52/0x90 drivers/tty/serial/8250/8250_core.c:513 console_init+0x1b8/0x6f0 kernel/printk/printk.c:4292 start_kernel+0x2dd/0x510 init/main.c:1034 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:515 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:496 common_startup_64+0x13e/0x147 } ... key at: [] port_lock_key+0x0/0x20 the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock: -> (disc_data_lock){.+.+}-{3:3} { HARDIRQ-ON-R at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 sp_get drivers/net/hamradio/6pack.c:370 [inline] sixpack_ioctl+0x81/0x550 drivers/net/hamradio/6pack.c:676 tty_ioctl+0x998/0xdc0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 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 SOFTIRQ-ON-R at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 sp_get drivers/net/hamradio/6pack.c:370 [inline] sixpack_ioctl+0x81/0x550 drivers/net/hamradio/6pack.c:676 tty_ioctl+0x998/0xdc0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 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 INITIAL USE at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline] _raw_write_lock_irq+0xd3/0x120 kernel/locking/spinlock.c:326 sixpack_close+0x2c/0x280 drivers/net/hamradio/6pack.c:641 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x174/0x200 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861 __fput+0x3e9/0x9f0 fs/file_table.c:464 task_work_run+0x24f/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x13f/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f INITIAL READ USE at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 sp_get drivers/net/hamradio/6pack.c:370 [inline] sixpack_ioctl+0x81/0x550 drivers/net/hamradio/6pack.c:676 tty_ioctl+0x998/0xdc0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 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 } ... key at: [] disc_data_lock+0x18/0x100 ... acquired at: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 sp_get drivers/net/hamradio/6pack.c:370 [inline] sixpack_write_wakeup+0x30/0x440 drivers/net/hamradio/6pack.c:391 tty_wakeup+0xbb/0x100 drivers/tty/tty_io.c:517 tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1844 __start_tx+0x32e/0x470 drivers/tty/serial/8250/8250_port.c:1549 __uart_start+0x2bc/0x450 drivers/tty/serial/serial_core.c:160 uart_write+0x280/0xa40 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+0x490/0x1640 drivers/net/hamradio/6pack.c:447 tty_ldisc_receive_buf+0x11f/0x170 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x6d/0xa0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x328/0x860 drivers/tty/tty_buffer.c:495 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 stack backtrace: CPU: 1 UID: 0 PID: 11417 Comm: kworker/u8:39 Not tainted 6.14.0-rc2-syzkaller-00034-gfebbc555cf0f #0 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+0x241/0x360 lib/dump_stack.c:120 print_bad_irq_dependency kernel/locking/lockdep.c:2649 [inline] check_irq_usage kernel/locking/lockdep.c:2890 [inline] check_prev_add kernel/locking/lockdep.c:3167 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x4ebd/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline] _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228 sp_get drivers/net/hamradio/6pack.c:370 [inline] sixpack_write_wakeup+0x30/0x440 drivers/net/hamradio/6pack.c:391 tty_wakeup+0xbb/0x100 drivers/tty/tty_io.c:517 tty_port_default_wakeup+0xa6/0xf0 drivers/tty/tty_port.c:69 serial8250_tx_chars+0x6e2/0x930 drivers/tty/serial/8250/8250_port.c:1844 __start_tx+0x32e/0x470 drivers/tty/serial/8250/8250_port.c:1549 __uart_start+0x2bc/0x450 drivers/tty/serial/serial_core.c:160 uart_write+0x280/0xa40 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+0x490/0x1640 drivers/net/hamradio/6pack.c:447 tty_ldisc_receive_buf+0x11f/0x170 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x6d/0xa0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x328/0x860 drivers/tty/tty_buffer.c:495 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244