syzbot


possible deadlock in kbd_event

Status: upstream: reported on 2025/10/14 00:10
Subsystems: fs serial
[Documentation on labels]
Reported-by: syzbot+781c8bb5e4d62cc883d3@syzkaller.appspotmail.com
First crash: 173d, last: 1d07h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
6a5e4858-605f-4a7b-9c77-899114b2fd94 repro possible deadlock in kbd_event 2026/03/06 01:30 2026/03/06 01:30 2026/03/06 01:38 31e9c887f7dc24e04b3ca70d0d54fc34141844b0
Discussions (5)
Title Replies (including bot) Last reply
[syzbot] Monthly serial report (Apr 2026) 0 (1) 2026/04/01 13:14
[syzbot] Monthly serial report (Nov 2025) 0 (1) 2025/11/27 12:43
[syzbot] Monthly kernfs report (Nov 2025) 0 (1) 2025/11/25 08:46
[syzbot] Monthly serial report (Oct 2025) 0 (1) 2025/10/27 05:54
[syzbot] [serial?] possible deadlock in kbd_event 0 (1) 2025/10/14 00:10

Sample crash report:
=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Tainted: G             L     
-----------------------------------------------------
syz.8.7188/27391 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff88802ba52468 (&tty->flow.lock){....}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
ffff88802ba52468 (&tty->flow.lock){....}-{3:3}, at: stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765

and this task is already holding:
ffffffff8effe078 (kbd_event_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
ffffffff8effe078 (kbd_event_lock){..-.}-{3:3}, at: class_spinlock_constructor include/linux/spinlock.h:586 [inline]
ffffffff8effe078 (kbd_event_lock){..-.}-{3:3}, at: kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510
which would create a new lock dependency:
 (kbd_event_lock){..-.}-{3:3} -> (&tty->flow.lock){....}-{3:3}

but this new dependency connects a SOFTIRQ-irq-safe lock:
 (kbd_event_lock){..-.}-{3:3}

... which became SOFTIRQ-irq-safe at:
  lock_acquire+0xf0/0x2e0 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:154
  spin_lock include/linux/spinlock.h:341 [inline]
  class_spinlock_constructor include/linux/spinlock.h:586 [inline]
  kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510
  input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
  input_pass_values+0x288/0x890 drivers/input/input.c:128
  input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
  input_event+0x89/0xe0 drivers/input/input.c:396
  rc_keydown+0x62/0x1e0 drivers/media/rc/rc-main.c:856
  imon_incoming_packet+0x1ecb/0x31c0 drivers/media/rc/imon.c:1677
  usb_rx_callback_intf0+0xba/0x210 drivers/media/rc/imon.c:1769
  __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
  dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
  __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
  __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
  hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
  handle_softirqs+0x22a/0x870 kernel/softirq.c:622
  __do_softirq kernel/softirq.c:656 [inline]
  invoke_softirq kernel/softirq.c:496 [inline]
  __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
  irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
  sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
  folios_put_refs+0x63b/0x8d0 mm/swap.c:-1
  free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:423
  __tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline]
  tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
  tlb_flush_mmu_free mm/mmu_gather.c:398 [inline]
  tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:405
  tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:530
  exit_mmap+0x498/0xa10 mm/mmap.c:1315
  __mmput+0x118/0x430 kernel/fork.c:1175
  exit_mm+0x168/0x220 kernel/exit.c:581
  do_exit+0x6a2/0x23c0 kernel/exit.c:964
  do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
  get_signal+0x1284/0x1330 kernel/signal.c:3034
  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+0x86/0x480 kernel/entry/common.c:98
  __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
  syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [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

to a SOFTIRQ-irq-unsafe lock:
 (tasklist_lock){.+.+}-{3:3}

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
  __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
  _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
  __do_wait+0xde/0x740 kernel/exit.c:1678
  do_wait+0x1e7/0x540 kernel/exit.c:1722
  kernel_wait+0xd6/0x1c0 kernel/exit.c:1898
  call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
  call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
  process_one_work kernel/workqueue.c:3276 [inline]
  process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
  worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
  kthread+0x388/0x470 kernel/kthread.c:436
  ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

other info that might help us debug this:

Chain exists of:
  kbd_event_lock --> &tty->flow.lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(kbd_event_lock);
                               lock(&tty->flow.lock);
  <Interrupt>
    lock(kbd_event_lock);

 *** DEADLOCK ***

5 locks held by syz.8.7188/27391:
 #0: ffff88802bd0b118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_write+0x1ae/0x4c0 drivers/input/evdev.c:511
 #1: ffff88802bb33230 (&dev->event_lock#2){..-.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
 #1: ffff88802bb33230 (&dev->event_lock#2){..-.}-{3:3}, at: input_inject_event+0xa5/0x340 drivers/input/input.c:419
 #2: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #2: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #2: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 #2: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: input_inject_event+0xb6/0x340 drivers/input/input.c:420
 #3: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #3: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #3: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 #3: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: input_pass_values+0x8d/0x890 drivers/input/input.c:119
 #4: ffffffff8effe078 (kbd_event_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
 #4: ffffffff8effe078 (kbd_event_lock){..-.}-{3:3}, at: class_spinlock_constructor include/linux/spinlock.h:586 [inline]
 #4: ffffffff8effe078 (kbd_event_lock){..-.}-{3:3}, at: kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (kbd_event_lock){..-.}-{3:3} {
   IN-SOFTIRQ-W at:
                    lock_acquire+0xf0/0x2e0 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:154
                    spin_lock include/linux/spinlock.h:341 [inline]
                    class_spinlock_constructor include/linux/spinlock.h:586 [inline]
                    kbd_event+0xd6/0x40d0 drivers/tty/vt/keyboard.c:1510
                    input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
                    input_pass_values+0x288/0x890 drivers/input/input.c:128
                    input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
                    input_event+0x89/0xe0 drivers/input/input.c:396
                    rc_keydown+0x62/0x1e0 drivers/media/rc/rc-main.c:856
                    imon_incoming_packet+0x1ecb/0x31c0 drivers/media/rc/imon.c:1677
                    usb_rx_callback_intf0+0xba/0x210 drivers/media/rc/imon.c:1769
                    __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
                    dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
                    __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
                    __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
                    hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
                    handle_softirqs+0x22a/0x870 kernel/softirq.c:622
                    __do_softirq kernel/softirq.c:656 [inline]
                    invoke_softirq kernel/softirq.c:496 [inline]
                    __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
                    irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
                    instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
                    sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
                    asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
                    folios_put_refs+0x63b/0x8d0 mm/swap.c:-1
                    free_pages_and_swap_cache+0x2e7/0x5b0 mm/swap_state.c:423
                    __tlb_batch_free_encoded_pages mm/mmu_gather.c:138 [inline]
                    tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
                    tlb_flush_mmu_free mm/mmu_gather.c:398 [inline]
                    tlb_flush_mmu+0x6d3/0xa30 mm/mmu_gather.c:405
                    tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:530
                    exit_mmap+0x498/0xa10 mm/mmap.c:1315
                    __mmput+0x118/0x430 kernel/fork.c:1175
                    exit_mm+0x168/0x220 kernel/exit.c:581
                    do_exit+0x6a2/0x23c0 kernel/exit.c:964
                    do_group_exit+0x21b/0x2d0 kernel/exit.c:1118
                    get_signal+0x1284/0x1330 kernel/signal.c:3034
                    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+0x86/0x480 kernel/entry/common.c:98
                    __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
                    syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [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
   INITIAL USE at:
                   lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
                   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
                   class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
                   vt_reset_unicode+0x2b/0x1a0 drivers/tty/vt/keyboard.c:2126
                   reset_vc+0x68/0x1b0 drivers/tty/vt/vt_ioctl.c:966
                   vc_init+0x70/0x4a0 drivers/tty/vt/vt.c:3729
                   con_init+0x377/0x6a0 drivers/tty/vt/vt.c:3795
                   console_init+0x10b/0x4d0 kernel/printk/printk.c:4407
                   start_kernel+0x22b/0x3d0 init/main.c:1147
                   x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
                   x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
                   common_startup_64+0x13e/0x147
 }
 ... key      at: [<ffffffff8effe078>] kbd_event_lock+0x18/0xa0 keyboard.c:-1

the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
   -> (tasklist_lock){.+.+}-{3:3} {
      HARDIRQ-ON-R at:
                          lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                          __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
                          _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                          __do_wait+0xde/0x740 kernel/exit.c:1678
                          do_wait+0x1e7/0x540 kernel/exit.c:1722
                          kernel_wait+0xd6/0x1c0 kernel/exit.c:1898
                          call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                          call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
                          process_one_work kernel/workqueue.c:3276 [inline]
                          process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
                          worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
                          kthread+0x388/0x470 kernel/kthread.c:436
                          ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
                          ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
      SOFTIRQ-ON-R at:
                          lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                          __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
                          _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                          __do_wait+0xde/0x740 kernel/exit.c:1678
                          do_wait+0x1e7/0x540 kernel/exit.c:1722
                          kernel_wait+0xd6/0x1c0 kernel/exit.c:1898
                          call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                          call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
                          process_one_work kernel/workqueue.c:3276 [inline]
                          process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
                          worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
                          kthread+0x388/0x470 kernel/kthread.c:436
                          ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
                          ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
      INITIAL USE at:
                         lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                         __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline]
                         _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                         copy_process+0x247a/0x3cd0 kernel/fork.c:2369
                         kernel_clone+0x248/0x8e0 kernel/fork.c:2653
                         user_mode_thread+0x110/0x180 kernel/fork.c:2729
                         rest_init+0x23/0x300 init/main.c:725
                         start_kernel+0x385/0x3d0 init/main.c:1210
                         x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
                         x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291
                         common_startup_64+0x13e/0x147
      INITIAL READ USE at:
                              lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                              __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
                              _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
                              __do_wait+0xde/0x740 kernel/exit.c:1678
                              do_wait+0x1e7/0x540 kernel/exit.c:1722
                              kernel_wait+0xd6/0x1c0 kernel/exit.c:1898
                              call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                              call_usermodehelper_exec_work+0xbe/0x230 kernel/umh.c:163
                              process_one_work kernel/workqueue.c:3276 [inline]
                              process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
                              worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
                              kthread+0x388/0x470 kernel/kthread.c:436
                              ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
                              ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
    }
    ... key      at: [<ffffffff8e40c058>] tasklist_lock+0x18/0x40
    ... acquired at:
   __raw_read_lock include/linux/rwlock_api_smp.h:161 [inline]
   _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:228
   send_sigurg+0x12b/0x420 fs/fcntl.c:978
   sk_send_sigurg+0x6c/0x2e0 net/core/sock.c:3669
   queue_oob+0x42c/0x4f0 net/unix/af_unix.c:2354
   unix_stream_sendmsg+0xcb1/0xe80 net/unix/af_unix.c:2488
   sock_sendmsg_nosec net/socket.c:727 [inline]
   __sock_sendmsg net/socket.c:742 [inline]
   ____sys_sendmsg+0x972/0x9f0 net/socket.c:2592
   ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
   __sys_sendmmsg+0x27c/0x4e0 net/socket.c:2735
   __do_sys_sendmmsg net/socket.c:2762 [inline]
   __se_sys_sendmmsg net/socket.c:2759 [inline]
   __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2759
   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

  -> (&f_owner->lock){....}-{3:3} {
     INITIAL USE at:
                       lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                       __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline]
                       _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                       __f_setown+0x67/0x370 fs/fcntl.c:136
                       generic_add_lease fs/locks.c:1908 [inline]
                       generic_setlease+0xacf/0xff0 fs/locks.c:1984
                       do_fcntl_add_lease+0x35e/0x470 fs/locks.c:2086
                       fcntl_setlease+0x123/0x180 fs/locks.c:2111
                       do_fcntl+0x8b3/0x1a20 fs/fcntl.c:535
                       __do_sys_fcntl fs/fcntl.c:602 [inline]
                       __se_sys_fcntl+0xc8/0x150 fs/fcntl.c:587
                       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
     INITIAL READ USE at:
                            lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                            __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
                            _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
                            send_sigio+0x38/0x370 fs/fcntl.c:918
                            kill_fasync_rcu fs/fcntl.c:1144 [inline]
                            kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159
                            lease_break_callback+0x26/0x30 fs/locks.c:577
                            __break_lease+0x81c/0x1e80 fs/locks.c:1657
                            break_deleg include/linux/filelock.h:504 [inline]
                            try_break_deleg+0xfc/0x180 include/linux/filelock.h:523
                            notify_change+0xb5a/0xf40 fs/attr.c:550
                            do_truncate+0x1c2/0x250 fs/open.c:68
                            handle_truncate fs/namei.c:4285 [inline]
                            do_open fs/namei.c:4681 [inline]
                            path_openat+0x2f89/0x3860 fs/namei.c:4836
                            do_file_open+0x23e/0x4a0 fs/namei.c:4865
                            do_sys_openat2+0x113/0x200 fs/open.c:1366
                            do_sys_open fs/open.c:1372 [inline]
                            __do_sys_openat fs/open.c:1388 [inline]
                            __se_sys_openat fs/open.c:1383 [inline]
                            __x64_sys_openat+0x138/0x170 fs/open.c:1383
                            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
   }
   ... key      at: [<ffffffff9a2f56e0>] file_f_owner_allocate.__key+0x0/0x20
   ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
   _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
   send_sigio+0x38/0x370 fs/fcntl.c:918
   kill_fasync_rcu fs/fcntl.c:1144 [inline]
   kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159
   lease_break_callback+0x26/0x30 fs/locks.c:577
   __break_lease+0x81c/0x1e80 fs/locks.c:1657
   break_deleg include/linux/filelock.h:504 [inline]
   try_break_deleg+0xfc/0x180 include/linux/filelock.h:523
   notify_change+0xb5a/0xf40 fs/attr.c:550
   do_truncate+0x1c2/0x250 fs/open.c:68
   handle_truncate fs/namei.c:4285 [inline]
   do_open fs/namei.c:4681 [inline]
   path_openat+0x2f89/0x3860 fs/namei.c:4836
   do_file_open+0x23e/0x4a0 fs/namei.c:4865
   do_sys_openat2+0x113/0x200 fs/open.c:1366
   do_sys_open fs/open.c:1372 [inline]
   __do_sys_openat fs/open.c:1388 [inline]
   __se_sys_openat fs/open.c:1383 [inline]
   __x64_sys_openat+0x138/0x170 fs/open.c:1383
   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

 -> (&new->fa_lock){...-}-{3:3} {
    IN-SOFTIRQ-R at:
                      lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                      __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
                      _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
                      kill_fasync_rcu fs/fcntl.c:1135 [inline]
                      kill_fasync+0x199/0x4d0 fs/fcntl.c:1159
                      hidraw_report_event+0x227/0x3b0 drivers/hid/hidraw.c:590
                      hid_report_raw_event+0x311/0x1730 drivers/hid/hid-core.c:2069
                      __hid_input_report drivers/hid/hid-core.c:2145 [inline]
                      hid_input_report+0x44b/0x580 drivers/hid/hid-core.c:2167
                      hid_irq_in+0x47e/0x6d0 drivers/hid/usbhid/hid-core.c:286
                      __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
                      dummy_timer+0xbbd/0x45d0 drivers/usb/gadget/udc/dummy_hcd.c:1995
                      __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
                      __hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
                      hrtimer_run_softirq+0x182/0x5a0 kernel/time/hrtimer.c:1866
                      handle_softirqs+0x22a/0x870 kernel/softirq.c:622
                      __do_softirq kernel/softirq.c:656 [inline]
                      invoke_softirq kernel/softirq.c:496 [inline]
                      __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
                      irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
                      instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
                      sysvec_apic_timer_interrupt+0x57/0xc0 arch/x86/kernel/apic/apic.c:1056
                      asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
    INITIAL USE at:
                     lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:211 [inline]
                     _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:326
                     fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:1012
                     lease_modify+0x4f7/0x6c0 fs/locks.c:1514
                     locks_remove_lease fs/locks.c:2757 [inline]
                     locks_remove_file+0x5f0/0xf70 fs/locks.c:2782
                     __fput+0x3ae/0xa70 fs/file_table.c:461
                     fput_close_sync+0x11f/0x240 fs/file_table.c:574
                     __do_sys_close fs/open.c:1509 [inline]
                     __se_sys_close fs/open.c:1494 [inline]
                     __x64_sys_close+0x7e/0x110 fs/open.c:1494
                     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
    INITIAL READ USE at:
                          lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                          __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
                          _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
                          kill_fasync_rcu fs/fcntl.c:1135 [inline]
                          kill_fasync+0x199/0x4d0 fs/fcntl.c:1159
                          lease_break_callback+0x26/0x30 fs/locks.c:577
                          __break_lease+0x81c/0x1e80 fs/locks.c:1657
                          break_deleg include/linux/filelock.h:504 [inline]
                          try_break_deleg+0xfc/0x180 include/linux/filelock.h:523
                          notify_change+0xb5a/0xf40 fs/attr.c:550
                          do_truncate+0x1c2/0x250 fs/open.c:68
                          handle_truncate fs/namei.c:4285 [inline]
                          do_open fs/namei.c:4681 [inline]
                          path_openat+0x2f89/0x3860 fs/namei.c:4836
                          do_file_open+0x23e/0x4a0 fs/namei.c:4865
                          do_sys_openat2+0x113/0x200 fs/open.c:1366
                          do_sys_open fs/open.c:1372 [inline]
                          __do_sys_openat fs/open.c:1388 [inline]
                          __se_sys_openat fs/open.c:1383 [inline]
                          __x64_sys_openat+0x138/0x170 fs/open.c:1383
                          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
  }
  ... key      at: [<ffffffff9a2f5700>] fasync_insert_entry.__key+0x0/0x20
  ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline]
   _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:236
   kill_fasync_rcu fs/fcntl.c:1135 [inline]
   kill_fasync+0x199/0x4d0 fs/fcntl.c:1159
   tty_wakeup drivers/tty/tty_io.c:515 [inline]
   __start_tty+0x18c/0x220 drivers/tty/tty_io.c:777
   start_tty drivers/tty/tty_io.c:794 [inline]
   tty_send_xchar+0x1d2/0x4d0 drivers/tty/tty_io.c:1153
   tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801
   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+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> (&tty->flow.lock){....}-{3:3} {
   INITIAL USE at:
                   lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
                   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
                   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
                   class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
                   start_tty+0x20/0x70 drivers/tty/tty_io.c:793
                   n_tty_set_termios+0xa7c/0x10c0 drivers/tty/n_tty.c:1848
                   tty_set_termios+0xdb3/0x1800 drivers/tty/tty_ioctl.c:348
                   set_termios+0x566/0x710 drivers/tty/tty_ioctl.c:516
                   tty_mode_ioctl+0x4a6/0x7d0 drivers/tty/tty_ioctl.c:-1
                   tty_ioctl+0x9c5/0xde0 drivers/tty/tty_io.c:2801
                   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+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
 }
 ... key      at: [<ffffffff9a5d4c60>] alloc_tty_struct.__key.35+0x0/0x20
 ... acquired at:
   __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
   _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
   class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
   stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765
   kbd_keycode drivers/tty/vt/keyboard.c:1497 [inline]
   kbd_event+0x2ec1/0x40d0 drivers/tty/vt/keyboard.c:1515
   input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
   input_pass_values+0x288/0x890 drivers/input/input.c:128
   input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
   input_inject_event+0x1dd/0x340 drivers/input/input.c:424
   evdev_write+0x325/0x4c0 drivers/input/evdev.c:528
   vfs_write+0x29a/0xb90 fs/read_write.c:686
   ksys_write+0x150/0x270 fs/read_write.c:740
   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


stack backtrace:
CPU: 1 UID: 0 PID: 27391 Comm: syz.8.7188 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:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline]
 check_irq_usage kernel/locking/lockdep.c:2857 [inline]
 check_prev_add kernel/locking/lockdep.c:3169 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x2a94/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
 class_spinlock_irqsave_constructor include/linux/spinlock.h:618 [inline]
 stop_tty+0x2f/0x150 drivers/tty/tty_io.c:765
 kbd_keycode drivers/tty/vt/keyboard.c:1497 [inline]
 kbd_event+0x2ec1/0x40d0 drivers/tty/vt/keyboard.c:1515
 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541
 input_pass_values+0x288/0x890 drivers/input/input.c:128
 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
 input_inject_event+0x1dd/0x340 drivers/input/input.c:424
 evdev_write+0x325/0x4c0 drivers/input/evdev.c:528
 vfs_write+0x29a/0xb90 fs/read_write.c:686
 ksys_write+0x150/0x270 fs/read_write.c:740
 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: 0033:0x7fe3d079c819
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:00007fe3d1663028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe3d0a15fa0 RCX: 00007fe3d079c819
RDX: 0000000000002250 RSI: 0000200000000040 RDI: 0000000000000006
RBP: 00007fe3d0832c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe3d0a16038 R14: 00007fe3d0a15fa0 R15: 00007fe3d0b3fa48
 </TASK>

Crashes (151):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/31 13:52 upstream d0c3bcd5b897 aeea1c72 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/30 17:03 upstream 7aaa8047eafd 458630d8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/27 20:02 upstream 46b513250491 74a13a23 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/26 06:45 upstream d2a43e7f89da c6143aac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/21 08:08 upstream c612261bedd6 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/15 06:50 upstream 69237f8c1f69 ee8d34d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/12 23:45 upstream 0257f64bdac7 2f7f359d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/12 10:37 upstream 80234b5ab240 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/11 00:56 upstream b4f0dd314b39 4683d576 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/10 21:06 upstream 1f318b96cc84 4683d576 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/04 11:36 upstream 0031c06807cf e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/03/03 13:54 upstream af4e9ef3d784 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/02/28 20:25 upstream 9197e5949a41 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/02/26 13:49 upstream d9d32e5bd5a4 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/02/20 17:24 upstream 8bf22c33e7a1 741f5161 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in kbd_event
2026/02/18 18:31 upstream 2961f841b025 77d4d919 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/02/09 11:26 upstream 05f7e89ab973 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/02/08 17:12 upstream e7aa57247700 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/02/02 11:10 upstream 18f7fcd5e69a 018ebef2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/18 06:48 upstream e84d960149e7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/18 03:44 upstream d3eeb99bbc99 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/17 03:12 upstream 39d3389331ab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/16 13:51 upstream 983d014aafb1 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/15 22:20 upstream 944aacb68baf d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in kbd_event
2026/01/08 17:45 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/08 09:32 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/06 01:08 upstream 7f98ab9da046 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/05 08:38 upstream 3609fa95fb0f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/03 23:02 upstream aacb0a6d604a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/03 09:21 upstream 805f9a061372 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/01 13:27 upstream b69053dd3ffb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2026/01/01 04:05 upstream 9528d5c091c5 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/12/05 13:37 upstream 2061f18ad76e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/12/05 00:13 upstream aa833fc394ba d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/12/04 10:45 upstream 559e608c4655 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/12/03 21:22 upstream a619fe35ab41 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/12/03 12:08 upstream 3f9f0252130e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/12/03 04:54 upstream 3f9f0252130e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/12/02 15:16 upstream 4a26e7032d7d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/12/02 01:09 upstream 1d18101a644e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/11/30 06:21 upstream 6bda50f4333f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/11/30 01:34 upstream 6bda50f4333f d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/11/28 21:22 upstream 6cf62f0174de d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/11/28 08:05 upstream e538109ac71d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/10/13 18:09 upstream 3a8660878839 b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/10/10 00:07 upstream 18a7e218cfcd 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce possible deadlock in kbd_event
2025/11/26 15:23 upstream 30f09200cc4a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 possible deadlock in kbd_event
2026/01/20 00:38 linux-next d08c85ac8894 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce possible deadlock in kbd_event
2025/12/05 01:33 linux-next bc04acf4aeca d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce possible deadlock in kbd_event
2025/10/10 07:40 linux-next 0b2f041c47ac ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in kbd_event
* Struck through repros no longer work on HEAD.