syzbot

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Tainted: G             L     
-----------------------------------------------------
syz.4.6328/29974 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffff888079d10c90 (&new->fa_lock){...-}-{3:3}, at: kill_fasync_rcu fs/fcntl.c:1135 [inline]
ffff888079d10c90 (&new->fa_lock){...-}-{3:3}, at: kill_fasync+0x199/0x4d0 fs/fcntl.c:1159

and this task is already holding:
ffff888080fcb028 (&client->buffer_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
ffff888080fcb028 (&client->buffer_lock){..-.}-{3:3}, at: evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261
which would create a new lock dependency:
 (&client->buffer_lock){..-.}-{3:3} -> (&new->fa_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+0x3e5/0x6b0 drivers/input/input.c:353
  input_event+0x84/0xc0 drivers/input/input.c:396
  hidinput_hid_event+0x143a/0x1ec0 drivers/hid/hid-input.c:1762
  hid_process_event+0x4be/0x620 drivers/hid/hid-core.c:1576
  hid_process_report drivers/hid/hid-core.c:1724 [inline]
  hid_report_raw_event+0xed6/0x1850 drivers/hid/hid-core.c:2095
  __hid_input_report+0x45c/0x590 drivers/hid/hid-core.c:2166
  hid_irq_in+0x495/0x710 drivers/hid/usbhid/hid-core.c:286
  __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
  lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
  __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]
  slab_pre_alloc_hook mm/slub.c:4520 [inline]
  slab_alloc_node mm/slub.c:4875 [inline]
  kmem_cache_alloc_noprof+0x40/0x650 mm/slub.c:4905
  vm_area_dup+0x2b/0x680 mm/vma_init.c:123
  dup_mmap+0x8b1/0x1d90 mm/mmap.c:1786
  dup_mm kernel/fork.c:1534 [inline]
  copy_mm+0x13b/0x4a0 kernel/fork.c:1586
  copy_process+0x1f1c/0x4440 kernel/fork.c:2264
  kernel_clone+0x284/0x8f0 kernel/fork.c:2721
  __do_sys_clone kernel/fork.c:2862 [inline]
  __se_sys_clone kernel/fork.c:2846 [inline]
  __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2846
  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:1679
  do_wait+0x1e7/0x510 kernel/exit.c:1723
  kernel_wait+0xd6/0x1c0 kernel/exit.c:1899
  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:3314 [inline]
  process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
  worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
  kthread+0x389/0x470 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 ***

7 locks held by syz.4.6328/29974:
 #0: ffff88823bf68910 (&evdev->mutex){+.+.}-{4:4}, at: evdev_write+0x1ae/0x4c0 drivers/input/evdev.c:511
 #1: ffff88801fb76230 (&dev->event_lock#2){..-.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:619 [inline]
 #1: ffff88801fb76230 (&dev->event_lock#2){..-.}-{3:3}, at: input_inject_event+0xa4/0x330 drivers/input/input.c:419
 #2: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #2: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
 #2: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: input_inject_event+0xb5/0x330 drivers/input/input.c:420
 #3: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #3: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #3: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
 #3: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: input_pass_values+0x8d/0x890 drivers/input/input.c:119
 #4: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #4: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #4: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: evdev_events+0x79/0x340 drivers/input/evdev.c:298
 #5: ffff888080fcb028 (&client->buffer_lock){..-.}-{3:3}, at: spin_lock include/linux/spinlock.h:342 [inline]
 #5: ffff888080fcb028 (&client->buffer_lock){..-.}-{3:3}, at: evdev_pass_values+0xb9/0xbd0 drivers/input/evdev.c:261
 #6: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #6: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #6: ffffffff8e95cde0 (rcu_read_lock){....}-{1:3}, at: kill_fasync+0x53/0x4d0 fs/fcntl.c:1158

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+0x3e5/0x6b0 drivers/input/input.c:353
                    input_event+0x84/0xc0 drivers/input/input.c:396
                    hidinput_hid_event+0x143a/0x1ec0 drivers/hid/hid-input.c:1762
                    hid_process_event+0x4be/0x620 drivers/hid/hid-core.c:1576
                    hid_process_report drivers/hid/hid-core.c:1724 [inline]
                    hid_report_raw_event+0xed6/0x1850 drivers/hid/hid-core.c:2095
                    __hid_input_report+0x45c/0x590 drivers/hid/hid-core.c:2166
                    hid_irq_in+0x495/0x710 drivers/hid/usbhid/hid-core.c:286
                    __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
                    lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
                    __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]
                    slab_pre_alloc_hook mm/slub.c:4520 [inline]
                    slab_alloc_node mm/slub.c:4875 [inline]
                    kmem_cache_alloc_noprof+0x40/0x650 mm/slub.c:4905
                    vm_area_dup+0x2b/0x680 mm/vma_init.c:123
                    dup_mmap+0x8b1/0x1d90 mm/mmap.c:1786
                    dup_mm kernel/fork.c:1534 [inline]
                    copy_mm+0x13b/0x4a0 kernel/fork.c:1586
                    copy_process+0x1f1c/0x4440 kernel/fork.c:2264
                    kernel_clone+0x284/0x8f0 kernel/fork.c:2721
                    __do_sys_clone kernel/fork.c:2862 [inline]
                    __se_sys_clone kernel/fork.c:2846 [inline]
                    __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2846
                    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_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_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: [<ffffffff9a7e38a0>] evdev_open.__key.27+0x0/0x20

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:1679
                        do_wait+0x1e7/0x510 kernel/exit.c:1723
                        kernel_wait+0xd6/0x1c0 kernel/exit.c:1899
                        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:3314 [inline]
                        process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
                        worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
                        kthread+0x389/0x470 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:1679
                        do_wait+0x1e7/0x510 kernel/exit.c:1723
                        kernel_wait+0xd6/0x1c0 kernel/exit.c:1899
                        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:3314 [inline]
                        process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
                        worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
                        kthread+0x389/0x470 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:1679
                            do_wait+0x1e7/0x510 kernel/exit.c:1723
                            kernel_wait+0xd6/0x1c0 kernel/exit.c:1899
                            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:3314 [inline]
                            process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
                            worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
                            kthread+0x389/0x470 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
                     fcntl_dirnotify+0x3f9/0x6a0 fs/notify/dnotify/dnotify.c:369
                     do_fcntl+0x77e/0x1a20 fs/fcntl.c:538
                     __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+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_parent include/linux/fsnotify.h:99 [inline]
                          fsnotify_dentry include/linux/fsnotify.h:108 [inline]
                          fsnotify_change+0x268/0x2c0 include/linux/fsnotify.h:495
                          notify_change+0xc55/0xf40 fs/attr.c:561
                          vfs_utimes+0x45a/0x660 fs/utimes.c:67
                          do_utimes_path fs/utimes.c:99 [inline]
                          do_utimes+0x1b9/0x2c0 fs/utimes.c:139
                          __do_sys_utime fs/utimes.c:220 [inline]
                          __se_sys_utime fs/utimes.c:209 [inline]
                          __x64_sys_utime+0x138/0x200 fs/utimes.c:209
                          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: [<ffffffff9a4c2880>] 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
   lease_break_callback+0x26/0x30 fs/locks.c:577
   __break_lease+0x81f/0x1ea0 fs/locks.c:1669
   break_lease include/linux/filelock.h:485 [inline]
   do_dentry_open+0x1010/0x14e0 fs/open.c:938
   vfs_open+0x3b/0x340 fs/open.c:1079
   do_open fs/namei.c:4699 [inline]
   path_openat+0x2e08/0x3860 fs/namei.c:4858
   do_file_open+0x23e/0x4a0 fs/namei.c:4887
   do_sys_openat2+0x113/0x200 fs/open.c:1364
   do_sys_open fs/open.c:1370 [inline]
   __do_sys_openat fs/open.c:1386 [inline]
   __se_sys_openat fs/open.c:1381 [inline]
   __x64_sys_openat+0x138/0x170 fs/open.c:1381
   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

-> (&new->fa_lock){...-}-{3:3} {
   IN-SOFTIRQ-R 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
                    sock_wake_async+0x137/0x160 net/socket.c:-1
                    sk_wake_async_rcu include/net/sock.h:2593 [inline]
                    sock_def_readable+0x3c1/0x550 net/core/sock.c:3616
                    tcp_data_queue+0x1e6f/0x5ea0 net/ipv4/tcp_input.c:5661
                    tcp_rcv_established+0xf86/0x2800 net/ipv4/tcp_input.c:6656
                    tcp_v4_do_rcv+0x903/0x13c0 net/ipv4/tcp_ipv4.c:1851
                    tcp_v4_rcv+0x26d4/0x3040 net/ipv4/tcp_ipv4.c:2244
                    ip_protocol_deliver_rcu+0x221/0x440 net/ipv4/ip_input.c:207
                    ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241
                    NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
                    NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
                    __netif_receive_skb_one_core net/core/dev.c:6202 [inline]
                    __netif_receive_skb net/core/dev.c:6315 [inline]
                    process_backlog+0xaa3/0x1950 net/core/dev.c:6666
                    __napi_poll+0xae/0x340 net/core/dev.c:7733
                    napi_poll net/core/dev.c:7796 [inline]
                    net_rx_action+0x627/0xf70 net/core/dev.c:7953
                    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
                    on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
                    stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline]
                    deref_stack_reg+0xb3/0x230 arch/x86/kernel/unwind_orc.c:419
                    unwind_next_frame+0x19d5/0x2550 arch/x86/kernel/unwind_orc.c:-1
                    arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
                    stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
                    kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
                    kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
                    slab_free_hook mm/slub.c:2650 [inline]
                    slab_free mm/slub.c:6250 [inline]
                    kmem_cache_free+0x44f/0x650 mm/slub.c:6377
                    __io_req_caches_free+0x1c1/0x270 io_uring/io_uring.c:2153
                    io_req_caches_free+0x1c/0x40 io_uring/io_uring.c:2165
                    io_ring_exit_work+0x42f/0x980 io_uring/io_uring.c:2367
                    process_one_work kernel/workqueue.c:3314 [inline]
                    process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
                    worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
                    kthread+0x389/0x470 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
                   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
                   exit_task_work include/linux/task_work.h:40 [inline]
                   do_exit+0x70f/0x22c0 kernel/exit.c:976
                   do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
                   get_signal+0x1284/0x1330 kernel/signal.c:3037
                   arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
                   __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
                   exit_to_user_mode_loop+0x8c/0x4d0 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
                        mousedev_write+0x8f9/0x950 drivers/input/mousedev.c:710
                        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: [<ffffffff9a4c28a0>] 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


stack backtrace:
CPU: 0 UID: 0 PID: 29974 Comm: syz.4.6328 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
 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
RIP: 0033:0x7f1aa099ce59
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:00007f1aa1822028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f1aa0c16090 RCX: 00007f1aa099ce59
RDX: 0000000000000037 RSI: 0000200000000040 RDI: 0000000000000005
RBP: 00007f1aa0a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1aa0c16128 R14: 00007f1aa0c16090 R15: 00007f1aa0d3fa48
 </TASK>