syzbot

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Tainted: G             L     
-----------------------------------------------------
syz.2.19886/16173 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff888075cf29a0 (&f_owner->lock){....}-{3:3}, at: send_sigio+0x38/0x370 fs/fcntl.c:918

and this task is already holding:
ffff8880565f3408 (&new->fa_lock){....}-{3:3}, at: kill_fasync_rcu fs/fcntl.c:1135 [inline]
ffff8880565f3408 (&new->fa_lock){....}-{3:3}, at: kill_fasync+0x199/0x4d0 fs/fcntl.c:1159
which would create a new lock dependency:
 (&new->fa_lock){....}-{3:3} -> (&f_owner->lock){....}-{3:3}

but this new dependency connects a SOFTIRQ-irq-safe lock:
 (&client->buffer_lock){..-.}-{3:3}

... which became SOFTIRQ-irq-safe 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]
  evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261
  evdev_events+0x1e6/0x340 drivers/input/evdev.c:306
  input_pass_values+0x288/0x890 drivers/input/input.c:128
  input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
  input_event+0x84/0xc0 drivers/input/input.c:396
  input_sync include/linux/input.h:464 [inline]
  xpad360_process_packet+0x641/0xdc0 drivers/input/joystick/xpad.c:933
  xpad_irq_in+0x14e/0x25c0 drivers/input/joystick/xpad.c:1226
  __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
  dummy_timer+0xbc0/0x4650 drivers/usb/gadget/udc/dummy_hcd.c:2005
  __run_hrtimer kernel/time/hrtimer.c:1930 [inline]
  __hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
  hrtimer_run_softirq+0x17a/0x240 kernel/time/hrtimer.c:2011
  handle_softirqs+0x22a/0x840 kernel/softirq.c:622
  __do_softirq kernel/softirq.c:656 [inline]
  invoke_softirq kernel/softirq.c:496 [inline]
  __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
  irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
  instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
  sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
  __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]
  dummy_queue+0x6e4/0x8d0 drivers/usb/gadget/udc/dummy_hcd.c:749
  usb_ep_queue+0xf1/0x3c0 drivers/usb/gadget/udc/core.c:303
  raw_process_ep_io+0x5e4/0xd90 drivers/usb/gadget/legacy/raw_gadget.c:1114
  raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1153 [inline]
  raw_ioctl+0x252c/0x41c0 drivers/usb/gadget/legacy/raw_gadget.c:1325
  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

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

... which became SOFTIRQ-irq-unsafe at:
...
  lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
  __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline]
  _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232
  __do_wait+0xde/0x740 kernel/exit.c:1677
  do_wait+0x1e7/0x510 kernel/exit.c:1721
  kernel_wait+0xd6/0x1c0 kernel/exit.c:1897
  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:3302 [inline]
  process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
  worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
  kthread+0x388/0x470 kernel/kthread.c:436
  ret_from_fork+0x514/0xb70 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:
  &client->buffer_lock --> &new->fa_lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(tasklist_lock);
                               local_irq_disable();
                               lock(&client->buffer_lock);
                               lock(&new->fa_lock);
  <Interrupt>
    lock(&client->buffer_lock);

 *** DEADLOCK ***

4 locks held by syz.2.19886/16173:
 #0: ffff88805a5a2c40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff88805a5a2c40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:721 [inline]
 #0: ffff88805a5a2c40 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1514
 #1: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:836 [inline]
 #1: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: sk_wake_async+0x7f/0x280 include/net/sock.h:2584
 #2: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #2: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: kill_fasync+0x53/0x4d0 fs/fcntl.c:1158
 #3: ffff8880565f3408 (&new->fa_lock){....}-{3:3}, at: kill_fasync_rcu fs/fcntl.c:1135 [inline]
 #3: ffff8880565f3408 (&new->fa_lock){....}-{3:3}, at: kill_fasync+0x199/0x4d0 fs/fcntl.c:1159

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
 -> (&client->buffer_lock){..-.}-{3:3} {
    IN-SOFTIRQ-W 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]
                      evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261
                      evdev_events+0x1e6/0x340 drivers/input/evdev.c:306
                      input_pass_values+0x288/0x890 drivers/input/input.c:128
                      input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
                      input_event+0x84/0xc0 drivers/input/input.c:396
                      input_sync include/linux/input.h:464 [inline]
                      xpad360_process_packet+0x641/0xdc0 drivers/input/joystick/xpad.c:933
                      xpad_irq_in+0x14e/0x25c0 drivers/input/joystick/xpad.c:1226
                      __usb_hcd_giveback_urb+0x376/0x540 drivers/usb/core/hcd.c:1657
                      dummy_timer+0xbc0/0x4650 drivers/usb/gadget/udc/dummy_hcd.c:2005
                      __run_hrtimer kernel/time/hrtimer.c:1930 [inline]
                      __hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
                      hrtimer_run_softirq+0x17a/0x240 kernel/time/hrtimer.c:2011
                      handle_softirqs+0x22a/0x840 kernel/softirq.c:622
                      __do_softirq kernel/softirq.c:656 [inline]
                      invoke_softirq kernel/softirq.c:496 [inline]
                      __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
                      irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
                      instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
                      sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
                      asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
                      __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]
                      dummy_queue+0x6e4/0x8d0 drivers/usb/gadget/udc/dummy_hcd.c:749
                      usb_ep_queue+0xf1/0x3c0 drivers/usb/gadget/udc/core.c:303
                      raw_process_ep_io+0x5e4/0xd90 drivers/usb/gadget/legacy/raw_gadget.c:1114
                      raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1153 [inline]
                      raw_ioctl+0x252c/0x41c0 drivers/usb/gadget/legacy/raw_gadget.c:1325
                      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
    INITIAL USE 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]
                     evdev_handle_get_val+0x70/0x9f0 drivers/input/evdev.c:898
                     evdev_do_ioctl drivers/input/evdev.c:-1 [inline]
                     evdev_ioctl_handler+0x127b/0x1fe0 drivers/input/evdev.c:1270
                     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
  }
  ... key      at: [<ffffffff9a7dd7e0>] evdev_open.__key.27+0x0/0x20
-> (&new->fa_lock){....}-{3:3} {
   INITIAL USE at:
                   lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:213 [inline]
                   _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:330
                   fasync_remove_entry+0xf1/0x1c0 fs/fcntl.c:1012
                   __fput+0x890/0xa60 fs/file_table.c:507
                   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:207 [inline]
                   syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
                   syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
                   do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   INITIAL READ USE at:
                        lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
                        __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline]
                        _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240
                        kill_fasync_rcu fs/fcntl.c:1135 [inline]
                        kill_fasync+0x199/0x4d0 fs/fcntl.c:1159
                        __pass_event drivers/input/evdev.c:240 [inline]
                        evdev_pass_values+0x627/0xbd0 drivers/input/evdev.c:278
                        evdev_events+0x1e6/0x340 drivers/input/evdev.c:306
                        input_pass_values+0x288/0x890 drivers/input/input.c:128
                        input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
                        input_inject_event+0x1dc/0x330 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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
                        entry_SYSCALL_64_after_hwframe+0x77/0x7f
 }
 ... key      at: [<ffffffff9a4bc8a0>] fasync_insert_entry.__key+0x0/0x20
 ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline]
   _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240
   kill_fasync_rcu fs/fcntl.c:1135 [inline]
   kill_fasync+0x199/0x4d0 fs/fcntl.c:1159
   __pass_event drivers/input/evdev.c:240 [inline]
   evdev_pass_values+0x627/0xbd0 drivers/input/evdev.c:278
   evdev_events+0x1e6/0x340 drivers/input/evdev.c:306
   input_pass_values+0x288/0x890 drivers/input/input.c:128
   input_event_dispose+0x330/0x6b0 drivers/input/input.c:342
   input_inject_event+0x1dc/0x330 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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f


the dependencies between the lock to be acquired
 and SOFTIRQ-irq-unsafe lock:
 -> (tasklist_lock){.+.+}-{3:3} {
    HARDIRQ-ON-R at:
                      lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
                      __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline]
                      _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232
                      __do_wait+0xde/0x740 kernel/exit.c:1677
                      do_wait+0x1e7/0x510 kernel/exit.c:1721
                      kernel_wait+0xd6/0x1c0 kernel/exit.c:1897
                      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:3302 [inline]
                      process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
                      worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
                      kthread+0x388/0x470 kernel/kthread.c:436
                      ret_from_fork+0x514/0xb70 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+0x106/0x350 kernel/locking/lockdep.c:5868
                      __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline]
                      _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232
                      __do_wait+0xde/0x740 kernel/exit.c:1677
                      do_wait+0x1e7/0x510 kernel/exit.c:1721
                      kernel_wait+0xd6/0x1c0 kernel/exit.c:1897
                      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:3302 [inline]
                      process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
                      worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
                      kthread+0x388/0x470 kernel/kthread.c:436
                      ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
                      ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
    INITIAL USE at:
                     lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:213 [inline]
                     _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:330
                     copy_process+0x2b4c/0x4440 kernel/fork.c:2411
                     kernel_clone+0x284/0x8f0 kernel/fork.c:2721
                     user_mode_thread+0x110/0x180 kernel/fork.c:2797
                     rest_init+0x23/0x300 init/main.c:727
                     start_kernel+0x38a/0x3e0 init/main.c:1220
                     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+0x106/0x350 kernel/locking/lockdep.c:5868
                          __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline]
                          _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232
                          __do_wait+0xde/0x740 kernel/exit.c:1677
                          do_wait+0x1e7/0x510 kernel/exit.c:1721
                          kernel_wait+0xd6/0x1c0 kernel/exit.c:1897
                          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:3302 [inline]
                          process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
                          worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
                          kthread+0x388/0x470 kernel/kthread.c:436
                          ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
                          ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
  }
  ... key      at: [<ffffffff8e60a058>] tasklist_lock+0x18/0x40
  ... acquired at:
   __raw_read_lock include/linux/rwlock_api_smp.h:163 [inline]
   _raw_read_lock+0x36/0x50 kernel/locking/spinlock.c:232
   send_sigurg+0x12b/0x420 fs/fcntl.c:978
   sk_send_sigurg+0x6c/0x2e0 net/core/sock.c:3672
   queue_oob+0x42c/0x4f0 net/unix/af_unix.c:2368
   unix_stream_sendmsg+0xcb1/0xe80 net/unix/af_unix.c:2502
   sock_sendmsg_nosec net/socket.c:787 [inline]
   __sock_sendmsg net/socket.c:802 [inline]
   ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
   ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
   __sys_sendmsg net/socket.c:2784 [inline]
   __do_sys_sendmsg net/socket.c:2789 [inline]
   __se_sys_sendmsg net/socket.c:2787 [inline]
   __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
   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

-> (&f_owner->lock){....}-{3:3} {
   INITIAL USE at:
                   lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:213 [inline]
                   _raw_write_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:330
                   __f_setown+0x67/0x370 fs/fcntl.c:136
                   f_setown+0x23a/0x300 fs/fcntl.c:183
                   sock_ioctl+0x615/0x7f0 net/socket.c:1375
                   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
   INITIAL READ USE at:
                        lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
                        __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline]
                        _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240
                        send_sigio+0x38/0x370 fs/fcntl.c:918
                        dnotify_handle_event+0x169/0x440 fs/notify/dnotify/dnotify.c:113
                        fsnotify_handle_event fs/notify/fsnotify.c:327 [inline]
                        send_to_group fs/notify/fsnotify.c:375 [inline]
                        fsnotify+0x1831/0x1ae0 fs/notify/fsnotify.c:592
                        fsnotify_name include/linux/fsnotify.h:55 [inline]
                        fsnotify_dirent include/linux/fsnotify.h:61 [inline]
                        fsnotify_create+0x121/0x180 include/linux/fsnotify.h:323
                        vfs_create+0x300/0x460 fs/namei.c:4206
                        filename_mknodat+0x3e8/0x660 fs/namei.c:5170
                        __do_sys_mknod fs/namei.c:5207 [inline]
                        __se_sys_mknod+0x3a/0x150 fs/namei.c:5204
                        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
 }
 ... key      at: [<ffffffff9a4bc880>] file_f_owner_allocate.__key+0x0/0x20
 ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline]
   _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240
   send_sigio+0x38/0x370 fs/fcntl.c:918
   kill_fasync_rcu fs/fcntl.c:1144 [inline]
   kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159
   sock_wake_async+0x137/0x160 net/socket.c:-1
   sk_wake_async+0x184/0x280 include/net/sock.h:2585
   unix_release_sock+0x74f/0xc80 net/unix/af_unix.c:712
   unix_release+0x92/0xd0 net/unix/af_unix.c:1184
   __sock_release net/socket.c:722 [inline]
   sock_close+0xc3/0x240 net/socket.c:1514
   __fput+0x44f/0xa60 fs/file_table.c:510
   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:207 [inline]
   syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
   syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
   do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
   entry_SYSCALL_64_after_hwframe+0x77/0x7f


stack backtrace:
CPU: 1 UID: 0 PID: 16173 Comm: syz.2.19886 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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+0x106/0x350 kernel/locking/lockdep.c:5868
 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline]
 _raw_read_lock_irqsave+0x48/0x60 kernel/locking/spinlock.c:240
 send_sigio+0x38/0x370 fs/fcntl.c:918
 kill_fasync_rcu fs/fcntl.c:1144 [inline]
 kill_fasync+0x24d/0x4d0 fs/fcntl.c:1159
 sock_wake_async+0x137/0x160 net/socket.c:-1
 sk_wake_async+0x184/0x280 include/net/sock.h:2585
 unix_release_sock+0x74f/0xc80 net/unix/af_unix.c:712
 unix_release+0x92/0xd0 net/unix/af_unix.c:1184
 __sock_release net/socket.c:722 [inline]
 sock_close+0xc3/0x240 net/socket.c:1514
 __fput+0x44f/0xa60 fs/file_table.c:510
 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:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f81b039cdd9
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:00007f81b117f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000021
RAX: 0000000000000004 RBX: 00007f81b0615fa0 RCX: 00007f81b039cdd9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 00007f81b0432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f81b0616038 R14: 00007f81b0615fa0 R15: 00007f81b073fa48
 </TASK>