===================================================== WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected 6.14.0-rc4-syzkaller #0 Not tainted ----------------------------------------------------- syz.4.2100/12812 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffffffff8f3525d8 (disc_data_lock#4){.+.+}-{3:3}, at: sp_get+0x18/0xf0 drivers/net/hamradio/6pack.c:370 and this task is already holding: ffffffff9ab81298 (&port_lock_key){-.-.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:715 [inline] ffffffff9ab81298 (&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#4){.+.+}-{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 __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:786 [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+0x419/0x1140 drivers/tty/n_tty.c:2389 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write.constprop.0+0x506/0x9a0 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:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 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 to a HARDIRQ-irq-unsafe lock: (disc_data_lock#4){.+.+}-{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_ioctl+0x74/0x430 drivers/net/hamradio/6pack.c:676 tty_ioctl+0x6ee/0x15d0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 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 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(disc_data_lock#4); local_irq_disable(); lock(&port_lock_key); lock(disc_data_lock#4); lock(&port_lock_key); *** DEADLOCK *** 4 locks held by syz.4.2100/12812: #0: ffff88805c6070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffff8880253b8ca0 (&buf->lock){+.+.}-{4:4}, at: tiocsti drivers/tty/tty_io.c:2297 [inline] #1: ffff8880253b8ca0 (&buf->lock){+.+.}-{4:4}, at: tty_ioctl+0x516/0x15d0 drivers/tty/tty_io.c:2716 #2: ffffffff9ab81298 (&port_lock_key){-.-.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:715 [inline] #2: ffffffff9ab81298 (&port_lock_key){-.-.}-{3:3}, at: uart_write+0x13b/0xb30 drivers/tty/serial/serial_core.c:626 #3: ffff88805c6070a0 (&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 __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:786 [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+0x419/0x1140 drivers/tty/n_tty.c:2389 iterate_tty_write drivers/tty/tty_io.c:1015 [inline] file_tty_write.constprop.0+0x506/0x9a0 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:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 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 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_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+0x61/0xe0 arch/x86/kernel/irq.c:278 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 variable_ffs arch/x86/include/asm/bitops.h:321 [inline] handle_softirqs+0x1da/0x8f0 kernel/softirq.c:549 __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 console_flush_all+0x9a4/0xc60 kernel/printk/printk.c:3211 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432 _printk+0xc8/0x100 kernel/printk/printk.c:2457 kauditd_printk_skb kernel/audit.c:546 [inline] kauditd_hold_skb+0x205/0x250 kernel/audit.c:581 kauditd_send_queue+0x236/0x290 kernel/audit.c:766 kauditd_thread+0x611/0xa60 kernel/audit.c:890 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_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:2782 serial8250_set_termios+0x6e/0x80 drivers/tty/serial/8250/8250_port.c:2907 uart_set_options+0x31b/0x5f0 drivers/tty/serial/serial_core.c:2311 serial8250_console_setup+0x18a/0x460 drivers/tty/serial/8250/8250_port.c:3528 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#4){.+.+}-{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_ioctl+0x74/0x430 drivers/net/hamradio/6pack.c:676 tty_ioctl+0x6ee/0x15d0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 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 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_ioctl+0x74/0x430 drivers/net/hamradio/6pack.c:676 tty_ioctl+0x6ee/0x15d0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 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_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+0x17b/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 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+0x27b/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_ioctl+0x74/0x430 drivers/net/hamradio/6pack.c:676 tty_ioctl+0x6ee/0x15d0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 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 } ... key at: [] disc_data_lock+0x18/0xfe0 ... 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 tiocsti drivers/tty/tty_io.c:2299 [inline] tty_ioctl+0x575/0x15d0 drivers/tty/tty_io.c:2716 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 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 stack backtrace: CPU: 1 UID: 0 PID: 12812 Comm: syz.4.2100 Not tainted 6.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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 tiocsti drivers/tty/tty_io.c:2299 [inline] tty_ioctl+0x575/0x15d0 drivers/tty/tty_io.c:2716 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 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 RIP: 0033:0x7fb30cb8d169 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:00007fb30a9f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb30cda6080 RCX: 00007fb30cb8d169 RDX: 0000400000000040 RSI: 0000000000005412 RDI: 0000000000000003 RBP: 00007fb30cc0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fb30cda6080 R15: 00007ffed9c757c8