================================
WARNING: inconsistent lock state
syzkaller #0 Tainted: G             L     
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/1/24 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffff88802aba4260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
ffff88802aba4260 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778
{SOFTIRQ-ON-W} state was registered at:
  lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
  lock_sock_nested+0x41/0x100 net/core/sock.c:3827
  lock_sock include/net/sock.h:1713 [inline]
  x25_accept+0xfa/0x8a0 net/x25/af_x25.c:885
  do_accept+0x521/0x750 net/socket.c:2059
  __sys_accept4_file net/socket.c:2093 [inline]
  __sys_accept4+0x139/0x230 net/socket.c:2115
  __do_sys_accept4 net/socket.c:2122 [inline]
  __se_sys_accept4 net/socket.c:2119 [inline]
  __x64_sys_accept4+0x9a/0xb0 net/socket.c:2119
  do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
  do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
  entry_SYSCALL_64_after_hwframe+0x77/0x7f
irq event stamp: 3525868
hardirqs last  enabled at (3525868): [<ffffffff8188e0f6>] __local_bh_enable_ip+0xd6/0x140 kernel/softirq.c:478
hardirqs last disabled at (3525867): [<ffffffff8188e092>] __local_bh_enable_ip+0x72/0x140 kernel/softirq.c:455
softirqs last  enabled at (3525806): [<ffffffff81890dd6>] run_ksoftirqd+0x36/0x60 kernel/softirq.c:1108
softirqs last disabled at (3525811): [<ffffffff81890dd6>] run_ksoftirqd+0x36/0x60 kernel/softirq.c:1108

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: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x33/0x2b0 net/core/dev.c:6269

stack backtrace:
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_usage_bug+0x28c/0x2e0 kernel/locking/lockdep.c:4058
 valid_state+0xbe/0xf0 kernel/locking/lockdep.c:4072
 mark_lock_irq+0x36/0x380 kernel/locking/lockdep.c:4283
 mark_lock+0x117/0x190 kernel/locking/lockdep.c:4769
 mark_usage kernel/locking/lockdep.c:-1 [inline]
 __lock_acquire+0x6b7/0x2e50 kernel/locking/lockdep.c:5208
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
 lock_sock_nested+0x41/0x100 net/core/sock.c:3827
 lock_sock include/net/sock.h:1713 [inline]
 x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778
 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138
 __netif_receive_skb_one_core net/core/dev.c:6245 [inline]
 netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6270
 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100
 __napi_poll+0xaa/0x330 net/core/dev.c:7768
 napi_poll net/core/dev.c:7831 [inline]
 net_rx_action+0x61d/0xf50 net/core/dev.c:7988
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1108
 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:3829
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:
[<ffffffff8188e2fb>] softirq_handle_begin kernel/softirq.c:486 [inline]
[<ffffffff8188e2fb>] handle_softirqs+0xab/0x860 kernel/softirq.c:621
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 __might_resched+0x36a/0x4c0 kernel/sched/core.c:9203
 lock_sock_nested+0x56/0x100 net/core/sock.c:3829
 lock_sock include/net/sock.h:1713 [inline]
 x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1778
 x25_lapb_receive_frame+0x1b0/0xfb0 net/x25/x25_dev.c:138
 __netif_receive_skb_one_core net/core/dev.c:6245 [inline]
 netif_receive_skb_core+0x2a6/0x2b0 net/core/dev.c:6270
 lapbeth_napi_poll+0x42/0x90 drivers/net/wan/lapbether.c:100
 __napi_poll+0xaa/0x330 net/core/dev.c:7768
 napi_poll net/core/dev.c:7831 [inline]
 net_rx_action+0x61d/0xf50 net/core/dev.c:7988
 handle_softirqs+0x226/0x860 kernel/softirq.c:645
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1108
 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>