================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. syz.2.858/9009 [HC0[0]:SC0[2]:HE1:SE0] takes: ffff88803165a868 (&dev->spinlock){?...}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline] ffff88803165a868 (&dev->spinlock){?...}-{3:3}, at: waveform_ao_cancel+0x8d/0x120 drivers/comedi/drivers/comedi_test.c:628 {IN-HARDIRQ-W} state was registered at: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] das16m1_interrupt+0x5e/0x180 drivers/comedi/drivers/das16m1.c:460 __handle_irq_event_percpu+0x216/0x9a0 kernel/irq/handle.c:209 handle_irq_event_percpu kernel/irq/handle.c:246 [inline] handle_irq_event+0x8b/0x1e0 kernel/irq/handle.c:263 handle_edge_irq+0x23b/0x9f0 kernel/irq/chip.c:855 generic_handle_irq_desc include/linux/irqdesc.h:186 [inline] handle_irq arch/x86/kernel/irq.c:262 [inline] call_irq_handler arch/x86/kernel/irq.c:-1 [inline] __common_interrupt+0x141/0x1f0 arch/x86/kernel/irq.c:333 common_interrupt+0xb6/0xe0 arch/x86/kernel/irq.c:326 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] uart_port_unlock_irqrestore include/linux/serial_core.h:788 [inline] autoconfig drivers/tty/serial/8250/8250_port.c:1201 [inline] serial8250_config_port+0x1464/0x53b0 drivers/tty/serial/8250/8250_port.c:3097 univ8250_config_port+0x3b9/0x980 drivers/tty/serial/8250/8250_rsa.c:72 uart_do_autoconfig drivers/tty/serial/serial_core.c:1173 [inline] uart_ioctl+0x1513/0x1aa0 drivers/tty/serial/serial_core.c:1565 tty_ioctl+0x928/0xde0 drivers/tty/tty_io.c:2792 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 8298 hardirqs last enabled at (8297): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] hardirqs last enabled at (8297): [] _raw_spin_unlock_irqrestore+0x30/0x80 kernel/locking/spinlock.c:198 hardirqs last disabled at (8296): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:130 [inline] hardirqs last disabled at (8296): [] _raw_spin_lock_irqsave+0x1a/0x60 kernel/locking/spinlock.c:166 softirqs last enabled at (8292): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (8292): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (8292): [] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 softirqs last disabled at (8298): [] spin_lock_bh include/linux/spinlock.h:348 [inline] softirqs last disabled at (8298): [] waveform_ao_cancel+0x8d/0x120 drivers/comedi/drivers/comedi_test.c:628 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dev->spinlock); lock(&dev->spinlock); *** DEADLOCK *** 1 lock held by syz.2.858/9009: #0: ffff88803165a8f0 (&dev->mutex#4){+.+.}-{4:4}, at: comedi_close+0x70/0x5e0 drivers/comedi/comedi_fops.c:3029 stack backtrace: CPU: 0 UID: 0 PID: 9009 Comm: syz.2.858 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_usage_bug+0x28b/0x2e0 kernel/locking/lockdep.c:4042 valid_state kernel/locking/lockdep.c:4056 [inline] mark_lock_irq+0x410/0x420 kernel/locking/lockdep.c:-1 mark_lock+0x115/0x190 kernel/locking/lockdep.c:4753 mark_usage kernel/locking/lockdep.c:4662 [inline] __lock_acquire+0x9d0/0x2cf0 kernel/locking/lockdep.c:5191 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:150 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:182 spin_lock_bh include/linux/spinlock.h:348 [inline] waveform_ao_cancel+0x8d/0x120 drivers/comedi/drivers/comedi_test.c:628 do_cancel drivers/comedi/comedi_fops.c:818 [inline] comedi_close+0x27e/0x5e0 drivers/comedi/comedi_fops.c:3036 __fput+0x44f/0xa60 fs/file_table.c:473 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff2d3f9c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fffee800cd8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007ff2d4217da0 RCX: 00007ff2d3f9c819 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007ff2d4217da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00000000003ffcc0 R11: 0000000000000246 R12: 000000000003ce79 R13: 00007ff2d4215fac R14: 000000000003cc1c R15: 00007ff2d4215fa0