cdc_wdm 10-1:1.0: wdm_int_callback - 0 bytes cdc_wdm 10-1:1.0: wdm_int_callback - usb_submit_urb failed with result -19 ================================ WARNING: inconsistent lock state syzkaller #0 Tainted: G L -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage. udevd/5893 [HC1[1]:SC0[0]:HE0:SE1] takes: ffff88803163c868 (&dev->spinlock){?...}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline] ffff88803163c868 (&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+0x451/0x8c0 fs/file_table.c:500 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:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f irq event stamp: 13208546 hardirqs last enabled at (13208545): [] seqcount_lockdep_reader_access+0xa9/0x100 include/linux/seqlock.h:75 hardirqs last disabled at (13208546): [] common_interrupt+0x13/0xe0 arch/x86/kernel/irq.c:326 softirqs last enabled at (13208170): [] local_bh_disable include/linux/bottom_half.h:20 [inline] softirqs last enabled at (13208170): [] __alloc_skb+0x186/0x7d0 net/core/skbuff.c:695 softirqs last disabled at (13208168): [] local_bh_disable include/linux/bottom_half.h:20 [inline] softirqs last disabled at (13208168): [] __alloc_skb+0x186/0x7d0 net/core/skbuff.c:695 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&dev->spinlock); lock(&dev->spinlock); *** DEADLOCK *** no locks held by udevd/5893. stack backtrace: CPU: 0 UID: 0 PID: 5893 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893 Code: 31 7b 11 00 00 00 00 eb b5 e8 e5 2e 0e 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 95 eb 7a 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 82 01 73 RSP: 0018:ffffc90003b17788 EFLAGS: 00000286 RAX: 18fc85bc8fe5e600 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8e1b3c90 RDI: ffffffff8c287c00 RBP: ffff88806cfba9d0 R08: ffffffff826e992c R09: ffffffff8e75d7e0 R10: dffffc0000000000 R11: ffffffff826ee310 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8e75d7e0 R15: ffff88806cfb9e80 rcu_lock_release include/linux/rcupdate.h:322 [inline] rcu_read_unlock include/linux/rcupdate.h:881 [inline] class_rcu_destructor include/linux/rcupdate.h:1193 [inline] kernfs_root+0x1e5/0x230 fs/kernfs/kernfs-internal.h:79 kernfs_dop_revalidate+0x8c/0x5e0 fs/kernfs/dir.c:1197 d_revalidate fs/namei.c:1030 [inline] lookup_fast+0x253/0x5b0 fs/namei.c:-1 walk_component fs/namei.c:2274 [inline] link_path_walk+0x720/0x18d0 fs/namei.c:2646 path_lookupat+0xe4/0x8c0 fs/namei.c:2802 filename_lookup+0x256/0x5d0 fs/namei.c:2832 vfs_statx+0xfc/0x200 fs/stat.c:353 vfs_fstatat+0x11b/0x170 fs/stat.c:373 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc9c2711b0a Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7 RSP: 002b:00007ffc45079888 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffc4507a180 RCX: 00007fc9c2711b0a RDX: 00007ffc450798f0 RSI: 00007ffc45079d80 RDI: 00000000ffffff9c RBP: 00007ffc45079d80 R08: 0202080000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000561564598140 R13: 00005615645a4930 R14: 0000561564588518 R15: 00005615470f4bcc comedi comedi3: fifo overflow ---------------- Code disassembly (best guess): 0: 31 7b 11 xor %edi,0x11(%rbx) 3: 00 00 add %al,(%rax) 5: 00 00 add %al,(%rax) 7: eb b5 jmp 0xffffffbe 9: e8 e5 2e 0e 0a call 0xa0e2ef3 e: f7 c3 00 02 00 00 test $0x200,%ebx 14: 74 b9 je 0xffffffcf 16: 65 48 8b 05 95 eb 7a mov %gs:0x117aeb95(%rip),%rax # 0x117aebb3 1d: 11 1e: 48 3b 44 24 28 cmp 0x28(%rsp),%rax 23: 75 44 jne 0x69 25: fb sti 26: 48 83 c4 30 add $0x30,%rsp * 2a: 5b pop %rbx <-- trapping instruction 2b: 41 5c pop %r12 2d: 41 5d pop %r13 2f: 41 5e pop %r14 31: 41 5f pop %r15 33: 5d pop %rbp 34: c3 ret 35: cc int3 36: cc int3 37: cc int3 38: cc int3 39: cc int3 3a: 48 rex.W 3b: 8d .byte 0x8d 3c: 3d .byte 0x3d 3d: 82 (bad) 3e: 01 .byte 0x1 3f: 73 .byte 0x73