================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. syz.8.6121/30618 [HC1[1]:SC0[0]:HE0:SE1] takes: ffff888031ced868 (&dev->spinlock){?...}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] ffff888031ced868 (&dev->spinlock){?...}-{3:3}, at: das16m1_interrupt+0x5e/0x180 drivers/comedi/drivers/das16m1.c:460 {HARDIRQ-ON-W} state was registered at: 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 irq event stamp: 70320 hardirqs last enabled at (70319): [] seqcount_lockdep_reader_access+0xa9/0x100 include/linux/seqlock.h:75 hardirqs last disabled at (70320): [] common_interrupt+0x13/0xe0 arch/x86/kernel/irq.c:326 softirqs last enabled at (68980): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (68980): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (68980): [] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 softirqs last disabled at (68933): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (68933): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (68933): [] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dev->spinlock); lock(&dev->spinlock); *** DEADLOCK *** 2 locks held by syz.8.6121/30618: #0: ffff888079b16410 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1132 [inline] #0: ffff888079b16410 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x3807/0x4530 fs/coredump.c:1206 #1: ffff888081aa6908 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #1: ffff888081aa6908 (&sb->s_type->i_mutex_key#15){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3456 stack backtrace: CPU: 0 UID: 0 PID: 30618 Comm: syz.8.6121 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:4639 [inline] __lock_acquire+0x661/0x2cf0 kernel/locking/lockdep.c:5191 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 RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x58/0x350 kernel/locking/lockdep.c:5831 Code: 8b 05 fc 4f 9f 11 48 89 44 24 58 0f 1f 44 00 00 65 8b 05 ff 4f 9f 11 83 f8 08 0f 83 83 01 00 00 89 c0 48 0f a3 05 a8 4e 91 0e <73> 0d e8 01 28 09 00 84 c0 0f 84 ca 01 00 00 83 3d 62 81 91 0e 00 RSP: 0018:ffffc9000347e438 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8ea839e0 RBP: ffffffff8221d952 R08: 0000000000000001 R09: 0000000000000000 R10: ffffc9000347e5a0 R11: fffff5200068fcb9 R12: 0000000000000000 R13: ffffffff8ea839e0 R14: 0000000000000000 R15: 0000000000000001 __fs_reclaim_acquire mm/page_alloc.c:4325 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4339 might_alloc include/linux/sched/mm.h:317 [inline] prepare_alloc_pages+0x152/0x650 mm/page_alloc.c:4995 __alloc_frozen_pages_noprof+0x12f/0x380 mm/page_alloc.c:5215 alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490 folio_alloc_mpol_noprof+0x39/0x160 mm/mempolicy.c:2509 shmem_alloc_folio mm/shmem.c:1933 [inline] shmem_alloc_and_add_folio+0x442/0xf80 mm/shmem.c:1975 shmem_get_folio_gfp+0x4d4/0x1420 mm/shmem.c:2552 shmem_get_folio mm/shmem.c:2658 [inline] shmem_write_begin+0x16c/0x330 mm/shmem.c:3291 generic_perform_write+0x2e2/0x8f0 mm/filemap.c:4325 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3466 __kernel_write_iter+0x41e/0x880 fs/read_write.c:621 dump_emit_page fs/coredump.c:1304 [inline] dump_user_range+0xc19/0x12c0 fs/coredump.c:1378 elf_core_dump+0x34c2/0x3ad0 fs/binfmt_elf.c:2109 coredump_write+0x1216/0x1910 fs/coredump.c:1053 do_coredump fs/coredump.c:1132 [inline] vfs_coredump+0x3807/0x4530 fs/coredump.c:1206 get_signal+0x1107/0x1330 kernel/signal.c:3022 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:283 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:352 [inline] irqentry_exit+0x188/0x700 kernel/entry/common.c:219 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7eff9b79c819 Code: Unable to access opcode bytes at 0x7eff9b79c7ef. RSP: 002b:00000000fffffeb0 EFLAGS: 00010206 RAX: 0000000000000000 RBX: 00007eff9ba15fa0 RCX: 00007eff9b79c819 RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000088820000 RBP: 00007eff9b832c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007eff9ba16038 R14: 00007eff9ba15fa0 R15: 00007ffeb93c2b78 comedi comedi0: fifo overflow ---------------- Code disassembly (best guess): 0: 8b 05 fc 4f 9f 11 mov 0x119f4ffc(%rip),%eax # 0x119f5002 6: 48 89 44 24 58 mov %rax,0x58(%rsp) b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 10: 65 8b 05 ff 4f 9f 11 mov %gs:0x119f4fff(%rip),%eax # 0x119f5016 17: 83 f8 08 cmp $0x8,%eax 1a: 0f 83 83 01 00 00 jae 0x1a3 20: 89 c0 mov %eax,%eax 22: 48 0f a3 05 a8 4e 91 bt %rax,0xe914ea8(%rip) # 0xe914ed2 29: 0e * 2a: 73 0d jae 0x39 <-- trapping instruction 2c: e8 01 28 09 00 call 0x92832 31: 84 c0 test %al,%al 33: 0f 84 ca 01 00 00 je 0x203 39: 83 3d 62 81 91 0e 00 cmpl $0x0,0xe918162(%rip) # 0xe9181a2