syzbot

=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
syzkaller #0 Tainted: G             L     
-----------------------------------------------------
syz.8.5536/23060 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffffffff8e00c098 (tasklist_lock){.+.+}-{3:3}, at: send_sigurg+0xed/0xc80 fs/fcntl.c:978

and this task is already holding:
ffff888064e3bda0 (&f_owner->lock){....}-{3:3}, at: send_sigurg+0x5f/0xc80 fs/fcntl.c:962
which would create a new lock dependency:
 (&f_owner->lock){....}-{3:3} -> (tasklist_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 kernel/locking/lockdep.c:5868 [inline]
  lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
  __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
  _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
  spin_lock include/linux/spinlock.h:351 [inline]
  evdev_pass_values+0x10e/0x9b0 drivers/input/evdev.c:261
  evdev_events+0x1bb/0x390 drivers/input/evdev.c:306
  input_pass_values+0x74e/0x880 drivers/input/input.c:128
  input_event_dispose drivers/input/input.c:353 [inline]
  input_handle_event+0xb29/0x14d0 drivers/input/input.c:370
  input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424
  kd_sound_helper+0x17a/0x280 drivers/tty/vt/keyboard.c:256
  input_handler_for_each_handle+0xd7/0x250 drivers/input/input.c:2520
  call_timer_fn+0x19a/0x5a0 kernel/time/timer.c:1748
  expire_timers kernel/time/timer.c:1799 [inline]
  __run_timers+0x74a/0xae0 kernel/time/timer.c:2373
  __run_timer_base kernel/time/timer.c:2385 [inline]
  __run_timer_base kernel/time/timer.c:2377 [inline]
  run_timer_base+0x114/0x190 kernel/time/timer.c:2394
  run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2404
  handle_softirqs+0x219/0x950 kernel/softirq.c:622
  __do_softirq kernel/softirq.c:656 [inline]
  invoke_softirq kernel/softirq.c:496 [inline]
  __irq_exit_rcu+0x109/0x170 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+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056
  asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
  ___slab_alloc+0x1ba/0x1c90 mm/slub.c:4531
  __kmem_cache_alloc_bulk+0x1fb/0x6c0 mm/slub.c:7424
  kmem_cache_alloc_bulk_noprof+0x4e1/0x800 mm/slub.c:7490
  __io_alloc_req_refill+0x9d/0x5e0 io_uring/io_uring.c:1025
  io_alloc_req io_uring/io_uring.h:562 [inline]
  io_submit_sqes+0xf94/0x28e0 io_uring/io_uring.c:2423
  __do_sys_io_uring_enter+0xd6b/0x1630 io_uring/io_uring.c:3277
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0xcd/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 kernel/locking/lockdep.c:5868 [inline]
  lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
  __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
  _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228
  __do_wait+0x105/0x890 kernel/exit.c:1672
  do_wait+0x21d/0x570 kernel/exit.c:1716
  kernel_wait+0x9f/0x160 kernel/exit.c:1892
  call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
  call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163
  process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
  process_scheduled_works kernel/workqueue.c:3340 [inline]
  worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
  kthread+0x3c5/0x780 kernel/kthread.c:463
  ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

other info that might help us debug this:

Chain exists of:
  &client->buffer_lock --> &f_owner->lock --> tasklist_lock

 Possible interrupt unsafe locking scenario:

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

 *** DEADLOCK ***

2 locks held by syz.8.5536/23060:
 #0: ffff8880347f6fe0 (&u->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #0: ffff8880347f6fe0 (&u->lock){+.+.}-{3:3}, at: queue_oob net/unix/af_unix.c:2336 [inline]
 #0: ffff8880347f6fe0 (&u->lock){+.+.}-{3:3}, at: unix_stream_sendmsg+0xd33/0x1320 net/unix/af_unix.c:2491
 #1: ffff888064e3bda0 (&f_owner->lock){....}-{3:3}, at: send_sigurg+0x5f/0xc80 fs/fcntl.c:962

the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
  -> (&client->buffer_lock){..-.}-{3:3} {
     IN-SOFTIRQ-W at:
                        lock_acquire kernel/locking/lockdep.c:5868 [inline]
                        lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                        __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
                        _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                        spin_lock include/linux/spinlock.h:351 [inline]
                        evdev_pass_values+0x10e/0x9b0 drivers/input/evdev.c:261
                        evdev_events+0x1bb/0x390 drivers/input/evdev.c:306
                        input_pass_values+0x74e/0x880 drivers/input/input.c:128
                        input_event_dispose drivers/input/input.c:353 [inline]
                        input_handle_event+0xb29/0x14d0 drivers/input/input.c:370
                        input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424
                        kd_sound_helper+0x17a/0x280 drivers/tty/vt/keyboard.c:256
                        input_handler_for_each_handle+0xd7/0x250 drivers/input/input.c:2520
                        call_timer_fn+0x19a/0x5a0 kernel/time/timer.c:1748
                        expire_timers kernel/time/timer.c:1799 [inline]
                        __run_timers+0x74a/0xae0 kernel/time/timer.c:2373
                        __run_timer_base kernel/time/timer.c:2385 [inline]
                        __run_timer_base kernel/time/timer.c:2377 [inline]
                        run_timer_base+0x114/0x190 kernel/time/timer.c:2394
                        run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2404
                        handle_softirqs+0x219/0x950 kernel/softirq.c:622
                        __do_softirq kernel/softirq.c:656 [inline]
                        invoke_softirq kernel/softirq.c:496 [inline]
                        __irq_exit_rcu+0x109/0x170 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+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056
                        asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
                        ___slab_alloc+0x1ba/0x1c90 mm/slub.c:4531
                        __kmem_cache_alloc_bulk+0x1fb/0x6c0 mm/slub.c:7424
                        kmem_cache_alloc_bulk_noprof+0x4e1/0x800 mm/slub.c:7490
                        __io_alloc_req_refill+0x9d/0x5e0 io_uring/io_uring.c:1025
                        io_alloc_req io_uring/io_uring.h:562 [inline]
                        io_submit_sqes+0xf94/0x28e0 io_uring/io_uring.c:2423
                        __do_sys_io_uring_enter+0xd6b/0x1630 io_uring/io_uring.c:3277
                        do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                        do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
                        entry_SYSCALL_64_after_hwframe+0x77/0x7f
     INITIAL USE at:
                       lock_acquire kernel/locking/lockdep.c:5868 [inline]
                       lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
                       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
                       spin_lock include/linux/spinlock.h:351 [inline]
                       evdev_pass_values+0x10e/0x9b0 drivers/input/evdev.c:261
                       evdev_events+0x1bb/0x390 drivers/input/evdev.c:306
                       input_pass_values+0x74e/0x880 drivers/input/input.c:128
                       input_event_dispose drivers/input/input.c:342 [inline]
                       input_handle_event+0xf00/0x14d0 drivers/input/input.c:370
                       input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424
                       evdev_write+0x457/0x750 drivers/input/evdev.c:528
                       vfs_write+0x2a0/0x11d0 fs/read_write.c:684
                       ksys_write+0x1f8/0x250 fs/read_write.c:738
                       do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                       do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
                       entry_SYSCALL_64_after_hwframe+0x77/0x7f
   }
   ... key      at: [<ffffffff9af1bba0>] __key.88+0x0/0x40
 -> (&new->fa_lock){...-}-{3:3} {
    IN-SOFTIRQ-R at:
                      lock_acquire kernel/locking/lockdep.c:5868 [inline]
                      lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                      __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
                      _raw_read_lock_irqsave+0x46/0x90 kernel/locking/spinlock.c:236
                      kill_fasync_rcu fs/fcntl.c:1135 [inline]
                      kill_fasync fs/fcntl.c:1159 [inline]
                      kill_fasync+0x138/0x510 fs/fcntl.c:1152
                      sock_wake_async+0x132/0x160 net/socket.c:1509
                      sk_wake_async_rcu include/net/sock.h:2570 [inline]
                      sk_wake_async_rcu include/net/sock.h:2567 [inline]
                      sock_def_readable+0x4f7/0x5d0 net/core/sock.c:3613
                      tcp_data_ready+0x114/0x5a0 net/ipv4/tcp_input.c:5371
                      tcp_data_queue+0x1ac2/0x4ff0 net/ipv4/tcp_input.c:5461
                      tcp_rcv_established+0xa7f/0x36e0 net/ipv4/tcp_input.c:6474
                      tcp_v4_do_rcv+0xc65/0x10a0 net/ipv4/tcp_ipv4.c:1881
                      tcp_v4_rcv+0x3077/0x4db0 net/ipv4/tcp_ipv4.c:2324
                      ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:207
                      ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:241
                      NF_HOOK include/linux/netfilter.h:318 [inline]
                      NF_HOOK include/linux/netfilter.h:312 [inline]
                      ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:262
                      dst_input include/net/dst.h:474 [inline]
                      ip_rcv_finish net/ipv4/ip_input.c:453 [inline]
                      NF_HOOK include/linux/netfilter.h:318 [inline]
                      NF_HOOK include/linux/netfilter.h:312 [inline]
                      ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:573
                      __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6137
                      __netif_receive_skb+0x1d/0x160 net/core/dev.c:6250
                      process_backlog+0x4a2/0x1650 net/core/dev.c:6602
                      __napi_poll.constprop.0+0xb3/0x540 net/core/dev.c:7666
                      napi_poll net/core/dev.c:7729 [inline]
                      net_rx_action+0x9f9/0xfa0 net/core/dev.c:7881
                      handle_softirqs+0x219/0x950 kernel/softirq.c:622
                      do_softirq kernel/softirq.c:523 [inline]
                      do_softirq+0xb2/0xf0 kernel/softirq.c:510
                      __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450
                      sk_stream_wait_memory+0x65c/0x10e0 net/core/stream.c:149
                      tcp_sendmsg_locked+0x15d0/0x42a0 net/ipv4/tcp.c:1365
                      tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1412
                      inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:859
                      sock_sendmsg_nosec net/socket.c:727 [inline]
                      __sock_sendmsg net/socket.c:742 [inline]
                      __sys_sendto+0x43c/0x520 net/socket.c:2206
                      __do_sys_sendto net/socket.c:2213 [inline]
                      __se_sys_sendto net/socket.c:2209 [inline]
                      __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2209
                      do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                      do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
                      entry_SYSCALL_64_after_hwframe+0x77/0x7f
    INITIAL USE at:
                     lock_acquire kernel/locking/lockdep.c:5868 [inline]
                     lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                     __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                     _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326
                     fasync_remove_entry+0xb2/0x1e0 fs/fcntl.c:1012
                     fasync_helper+0xaf/0xd0 fs/fcntl.c:1115
                     lease_modify+0x232/0x500 fs/locks.c:1455
                     locks_remove_lease fs/locks.c:2726 [inline]
                     locks_remove_file+0x29e/0x5c0 fs/locks.c:2751
                     __fput+0x351/0xb70 fs/file_table.c:460
                     task_work_run+0x150/0x240 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:44 [inline]
                     exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75
                     __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_work include/linux/entry-common.h:159 [inline]
                     syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
                     do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
                     entry_SYSCALL_64_after_hwframe+0x77/0x7f
    INITIAL READ USE at:
                          lock_acquire kernel/locking/lockdep.c:5868 [inline]
                          lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                          __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
                          _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236
                          kill_fasync_rcu fs/fcntl.c:1135 [inline]
                          kill_fasync fs/fcntl.c:1159 [inline]
                          kill_fasync+0x138/0x510 fs/fcntl.c:1152
                          lease_break_callback+0x23/0x30 fs/locks.c:558
                          __break_lease+0x6cd/0x1800 fs/locks.c:1598
                          break_lease include/linux/filelock.h:476 [inline]
                          do_dentry_open+0x6e7/0x1590 fs/open.c:953
                          vfs_open+0x82/0x3f0 fs/open.c:1094
                          do_open fs/namei.c:4628 [inline]
                          path_openat+0x2078/0x3140 fs/namei.c:4787
                          do_filp_open+0x20b/0x470 fs/namei.c:4814
                          do_sys_openat2+0x11f/0x280 fs/open.c:1430
                          do_sys_open fs/open.c:1436 [inline]
                          __do_sys_open fs/open.c:1444 [inline]
                          __se_sys_open fs/open.c:1440 [inline]
                          __x64_sys_open+0x153/0x1e0 fs/open.c:1440
                          do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                          do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
                          entry_SYSCALL_64_after_hwframe+0x77/0x7f
  }
  ... key      at: [<ffffffff9ac43380>] __key.0+0x0/0x40
  ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
   _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236
   kill_fasync_rcu fs/fcntl.c:1135 [inline]
   kill_fasync fs/fcntl.c:1159 [inline]
   kill_fasync+0x138/0x510 fs/fcntl.c:1152
   __pass_event drivers/input/evdev.c:240 [inline]
   evdev_pass_values+0x619/0x9b0 drivers/input/evdev.c:278
   evdev_events+0x1bb/0x390 drivers/input/evdev.c:306
   input_pass_values+0x74e/0x880 drivers/input/input.c:128
   input_event_dispose drivers/input/input.c:342 [inline]
   input_handle_event+0xf00/0x14d0 drivers/input/input.c:370
   input_inject_event+0x1e8/0x3b0 drivers/input/input.c:424
   evdev_write+0x457/0x750 drivers/input/evdev.c:528
   vfs_write+0x2a0/0x11d0 fs/read_write.c:684
   ksys_write+0x1f8/0x250 fs/read_write.c:738
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xcd/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 kernel/locking/lockdep.c:5868 [inline]
                   lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                   _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326
                   __f_setown+0x61/0x3c0 fs/fcntl.c:136
                   fcntl_dirnotify+0x7b1/0xb60 fs/notify/dnotify/dnotify.c:369
                   do_fcntl+0x504/0x1660 fs/fcntl.c:538
                   __do_sys_fcntl fs/fcntl.c:602 [inline]
                   __se_sys_fcntl fs/fcntl.c:587 [inline]
                   __x64_sys_fcntl+0x163/0x200 fs/fcntl.c:587
                   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                   do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
                   entry_SYSCALL_64_after_hwframe+0x77/0x7f
   INITIAL READ USE at:
                        lock_acquire kernel/locking/lockdep.c:5868 [inline]
                        lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                        __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
                        _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236
                        send_sigio+0x31/0x3e0 fs/fcntl.c:918
                        kill_fasync_rcu fs/fcntl.c:1144 [inline]
                        kill_fasync fs/fcntl.c:1159 [inline]
                        kill_fasync+0x214/0x510 fs/fcntl.c:1152
                        lease_break_callback+0x23/0x30 fs/locks.c:558
                        __break_lease+0x6cd/0x1800 fs/locks.c:1598
                        break_lease include/linux/filelock.h:476 [inline]
                        do_dentry_open+0x6e7/0x1590 fs/open.c:953
                        vfs_open+0x82/0x3f0 fs/open.c:1094
                        do_open fs/namei.c:4628 [inline]
                        path_openat+0x2078/0x3140 fs/namei.c:4787
                        do_filp_open+0x20b/0x470 fs/namei.c:4814
                        do_sys_openat2+0x11f/0x280 fs/open.c:1430
                        do_sys_open fs/open.c:1436 [inline]
                        __do_sys_open fs/open.c:1444 [inline]
                        __se_sys_open fs/open.c:1440 [inline]
                        __x64_sys_open+0x153/0x1e0 fs/open.c:1440
                        do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
                        do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
                        entry_SYSCALL_64_after_hwframe+0x77/0x7f
 }
 ... key      at: [<ffffffff9ac433c0>] __key.1+0x0/0x40
 ... acquired at:
   __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
   _raw_read_lock_irqsave+0x74/0x90 kernel/locking/spinlock.c:236
   send_sigio+0x31/0x3e0 fs/fcntl.c:918
   kill_fasync_rcu fs/fcntl.c:1144 [inline]
   kill_fasync fs/fcntl.c:1159 [inline]
   kill_fasync+0x214/0x510 fs/fcntl.c:1152
   lease_break_callback+0x23/0x30 fs/locks.c:558
   __break_lease+0x6cd/0x1800 fs/locks.c:1598
   break_lease include/linux/filelock.h:476 [inline]
   do_dentry_open+0x6e7/0x1590 fs/open.c:953
   vfs_open+0x82/0x3f0 fs/open.c:1094
   do_open fs/namei.c:4628 [inline]
   path_openat+0x2078/0x3140 fs/namei.c:4787
   do_filp_open+0x20b/0x470 fs/namei.c:4814
   do_sys_openat2+0x11f/0x280 fs/open.c:1430
   do_sys_open fs/open.c:1436 [inline]
   __do_sys_open fs/open.c:1444 [inline]
   __se_sys_open fs/open.c:1440 [inline]
   __x64_sys_open+0x153/0x1e0 fs/open.c:1440
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xcd/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 kernel/locking/lockdep.c:5868 [inline]
                    lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                    __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                    _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228
                    __do_wait+0x105/0x890 kernel/exit.c:1672
                    do_wait+0x21d/0x570 kernel/exit.c:1716
                    kernel_wait+0x9f/0x160 kernel/exit.c:1892
                    call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                    call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163
                    process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
                    process_scheduled_works kernel/workqueue.c:3340 [inline]
                    worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
                    kthread+0x3c5/0x780 kernel/kthread.c:463
                    ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
                    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
   SOFTIRQ-ON-R at:
                    lock_acquire kernel/locking/lockdep.c:5868 [inline]
                    lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                    __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                    _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228
                    __do_wait+0x105/0x890 kernel/exit.c:1672
                    do_wait+0x21d/0x570 kernel/exit.c:1716
                    kernel_wait+0x9f/0x160 kernel/exit.c:1892
                    call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                    call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163
                    process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
                    process_scheduled_works kernel/workqueue.c:3340 [inline]
                    worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
                    kthread+0x3c5/0x780 kernel/kthread.c:463
                    ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
                    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
   INITIAL USE at:
                   lock_acquire kernel/locking/lockdep.c:5868 [inline]
                   lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                   __raw_write_lock_irq include/linux/rwlock_api_smp.h:195 [inline]
                   _raw_write_lock_irq+0x36/0x50 kernel/locking/spinlock.c:326
                   copy_process+0x4668/0x7430 kernel/fork.c:2367
                   kernel_clone+0xfc/0x910 kernel/fork.c:2651
                   user_mode_thread+0xc8/0x110 kernel/fork.c:2727
                   rest_init+0x23/0x2b0 init/main.c:722
                   start_kernel+0x3ef/0x4d0 init/main.c:1206
                   x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
                   x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
                   common_startup_64+0x13e/0x148
   INITIAL READ USE at:
                        lock_acquire kernel/locking/lockdep.c:5868 [inline]
                        lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
                        __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
                        _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228
                        __do_wait+0x105/0x890 kernel/exit.c:1672
                        do_wait+0x21d/0x570 kernel/exit.c:1716
                        kernel_wait+0x9f/0x160 kernel/exit.c:1892
                        call_usermodehelper_exec_sync kernel/umh.c:136 [inline]
                        call_usermodehelper_exec_work+0xf1/0x170 kernel/umh.c:163
                        process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
                        process_scheduled_works kernel/workqueue.c:3340 [inline]
                        worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
                        kthread+0x3c5/0x780 kernel/kthread.c:463
                        ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
                        ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 }
 ... key      at: [<ffffffff8e00c098>] tasklist_lock+0x18/0x40
 ... acquired at:
   lock_acquire kernel/locking/lockdep.c:5868 [inline]
   lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
   __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
   _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228
   send_sigurg+0xed/0xc80 fs/fcntl.c:978
   sk_send_sigurg+0x76/0x360 net/core/sock.c:3669
   queue_oob net/unix/af_unix.c:2357 [inline]
   unix_stream_sendmsg+0xfa3/0x1320 net/unix/af_unix.c:2491
   sock_sendmsg_nosec net/socket.c:727 [inline]
   __sock_sendmsg net/socket.c:742 [inline]
   ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592
   ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646
   __sys_sendmsg+0x16d/0x220 net/socket.c:2678
   do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
   do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
   entry_SYSCALL_64_after_hwframe+0x77/0x7f


stack backtrace:
CPU: 1 UID: 60928 PID: 23060 Comm: syz.8.5536 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_bad_irq_dependency kernel/locking/lockdep.c:2616 [inline]
 check_irq_usage+0x8e6/0xbc0 kernel/locking/lockdep.c:2857
 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+0x167f/0x2890 kernel/locking/lockdep.c:5237
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825
 __raw_read_lock include/linux/rwlock_api_smp.h:150 [inline]
 _raw_read_lock+0x5f/0x70 kernel/locking/spinlock.c:228
 send_sigurg+0xed/0xc80 fs/fcntl.c:978
 sk_send_sigurg+0x76/0x360 net/core/sock.c:3669
 queue_oob net/unix/af_unix.c:2357 [inline]
 unix_stream_sendmsg+0xfa3/0x1320 net/unix/af_unix.c:2491
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646
 __sys_sendmsg+0x16d/0x220 net/socket.c:2678
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa23f98f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa24082e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa23fbe5fa0 RCX: 00007fa23f98f749
RDX: 00000000240408c1 RSI: 0000200000000080 RDI: 0000000000000003
RBP: 00007fa23fa13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa23fbe6038 R14: 00007fa23fbe5fa0 R15: 00007ffca797f688
 </TASK>