================================
WARNING: inconsistent lock state
syzkaller #0 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/1/24 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffff88807f1f2260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
ffff88807f1f2260 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1775
{SOFTIRQ-ON-W} state was registered at:
  lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
  lock_sock_nested+0x41/0x100 net/core/sock.c:3837
  lock_sock include/net/sock.h:1713 [inline]
  x25_release+0xa0/0x3d0 net/x25/af_x25.c:629
  __sock_release+0xa0/0x1f0 net/socket.c:735
  sock_close+0x1c/0x30 net/socket.c:1529
  __fput+0x418/0xa50 fs/file_table.c:512
  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:70 [inline]
  exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
  __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:230 [inline]
  syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
  do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
  entry_SYSCALL_64_after_hwframe+0x77/0x7f
irq event stamp: 1538138
hardirqs last  enabled at (1538138): [<ffffffff8188f096>] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478
hardirqs last disabled at (1538137): [<ffffffff8188f032>] __local_bh_enable_ip+0x72/0x140 kernel/softirq.c:455
softirqs last  enabled at (1538058): [<ffffffff81891d76>] run_ksoftirqd+0x36/0x60 kernel/softirq.c:1099
softirqs last disabled at (1538065): [<ffffffff81891d76>] run_ksoftirqd+0x36/0x60 kernel/softirq.c:1099

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(sk_lock-AF_X25);
  <Interrupt>
    lock(sk_lock-AF_X25);

 *** DEADLOCK ***

locks held by ksoftirqd/1/24: 1, last CPU#1:
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6357

stack backtrace:
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_usage_bug+0x28c/0x2e0 kernel/locking/lockdep.c:4086
 valid_state+0xbe/0xf0 kernel/locking/lockdep.c:4100
 mark_lock_irq+0x36/0x380 kernel/locking/lockdep.c:4311
 mark_lock+0x117/0x190 kernel/locking/lockdep.c:4797
 mark_usage kernel/locking/lockdep.c:-1 [inline]
 __lock_acquire+0x71e/0x2de0 kernel/locking/lockdep.c:5242
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 lock_sock_nested+0x41/0x100 net/core/sock.c:3837
 lock_sock include/net/sock.h:1713 [inline]
 x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1775
 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138
 __netif_receive_skb_one_core net/core/dev.c:6333 [inline]
 netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6358
 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100
 __napi_poll+0xaa/0x330 net/core/dev.c:7866
 napi_poll net/core/dev.c:7929 [inline]
 net_rx_action+0x61d/0xf50 net/core/dev.c:8086
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1099
 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
 kthread+0x38b/0x480 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
 </TASK>
BUG: sleeping function called from invalid context at net/core/sock.c:3839
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 24, name: ksoftirqd/1
preempt_count: 100, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff8188f29b>] softirq_handle_begin kernel/softirq.c:486 [inline]
[<ffffffff8188f29b>] handle_softirqs+0xab/0x860 kernel/softirq.c:621
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 __might_resched+0x36a/0x4c0 kernel/sched/core.c:9264
 lock_sock_nested+0x56/0x100 net/core/sock.c:3839
 lock_sock include/net/sock.h:1713 [inline]
 x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1775
 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138
 __netif_receive_skb_one_core net/core/dev.c:6333 [inline]
 netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6358
 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100
 __napi_poll+0xaa/0x330 net/core/dev.c:7866
 napi_poll net/core/dev.c:7929 [inline]
 net_rx_action+0x61d/0xf50 net/core/dev.c:8086
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1099
 smpboot_thread_fn+0x565/0xa70 kernel/smpboot.c:160
 kthread+0x38b/0x480 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
 </TASK>