================================
WARNING: inconsistent lock state
syzkaller #0 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
syz.1.674/7992 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffff888077f82130 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
ffff888077f82130 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782
{SOFTIRQ-ON-W} state was registered at:
  lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
  lock_sock_nested+0x48/0x100 net/core/sock.c:3544
  lock_sock include/net/sock.h:1780 [inline]
  x25_bind+0x20a/0x460 net/x25/af_x25.c:698
  __sys_bind+0x2f0/0x3f0 net/socket.c:1856
  __do_sys_bind net/socket.c:1867 [inline]
  __se_sys_bind net/socket.c:1865 [inline]
  __x64_sys_bind+0x7a/0x90 net/socket.c:1865
  do_syscall_x64 arch/x86/entry/common.c:46 [inline]
  do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
  entry_SYSCALL_64_after_hwframe+0x68/0xd2
irq event stamp: 34488
hardirqs last  enabled at (34488): [<ffffffff8152ccba>] __local_bh_enable_ip+0x13a/0x1c0 kernel/softirq.c:411
hardirqs last disabled at (34487): [<ffffffff8152cc5b>] __local_bh_enable_ip+0xdb/0x1c0 kernel/softirq.c:388
softirqs last  enabled at (32184): [<ffffffff8152d8f3>] __do_softirq kernel/softirq.c:612 [inline]
softirqs last  enabled at (32184): [<ffffffff8152d8f3>] invoke_softirq kernel/softirq.c:452 [inline]
softirqs last  enabled at (32184): [<ffffffff8152d8f3>] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
softirqs last disabled at (34101): [<ffffffff8152d8f3>] __do_softirq kernel/softirq.c:612 [inline]
softirqs last disabled at (34101): [<ffffffff8152d8f3>] invoke_softirq kernel/softirq.c:452 [inline]
softirqs last disabled at (34101): [<ffffffff8152d8f3>] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661

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 ***

3 locks held by syz.1.674/7992:
 #0: ffff88807e7f14a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:146 [inline]
 #0: ffff88807e7f14a0 (&mm->mmap_lock){++++}-{3:3}, at: __mm_populate+0x183/0x390 mm/gup.c:1675
 #1: ffff8880b8f36c78 (lock#4){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
 #1: ffff8880b8f36c78 (lock#4){+.+.}-{2:2}, at: folio_add_lru+0x323/0xce0 mm/swap.c:507
 #2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb_core+0x34/0x230 net/core/dev.c:5670

stack backtrace:
CPU: 1 PID: 7992 Comm: syz.1.674 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 valid_state+0x13b/0x1d0 kernel/locking/lockdep.c:4013
 mark_lock_irq+0xad/0x900 kernel/locking/lockdep.c:4216
 mark_lock+0x208/0x320 kernel/locking/lockdep.c:4678
 mark_usage kernel/locking/lockdep.c:-1 [inline]
 __lock_acquire+0xcfc/0x7d80 kernel/locking/lockdep.c:5091
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 lock_sock_nested+0x48/0x100 net/core/sock.c:3544
 lock_sock include/net/sock.h:1780 [inline]
 x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782
 x25_lapb_receive_frame+0x1a7/0xef0 net/x25/x25_dev.c:138
 __netif_receive_skb_one_core net/core/dev.c:5646 [inline]
 netif_receive_skb_core+0x16a/0x230 net/core/dev.c:5671
 lapbeth_napi_poll+0x42/0x80 drivers/net/wan/lapbether.c:99
 __napi_poll+0xbb/0x460 net/core/dev.c:6650
 napi_poll net/core/dev.c:6717 [inline]
 net_rx_action+0x65f/0xcc0 net/core/dev.c:6853
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 6b 28 c4 f6 65 8b 05 cc f6 6a 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000523f4c0 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: f9a6e1d121d66d00
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001
RBP: ffffc9000523f550 R08: ffffffff911ed547 R09: 1ffffffff223daa8
R10: dffffc0000000000 R11: fffffbfff223daa9 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88807cdfa050 R15: 1ffff92000a47e98
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1618 [inline]
 folio_batch_move_lru+0x546/0x660 mm/swap.c:215
 folio_add_lru+0x41c/0xce0 mm/swap.c:509
 shmem_get_folio_gfp+0x1124/0x2b40 mm/shmem.c:2077
 shmem_fault+0x1b8/0x820 mm/shmem.c:2248
 __do_fault+0x13b/0x4d0 mm/memory.c:4244
 do_read_fault mm/memory.c:4638 [inline]
 do_fault mm/memory.c:4775 [inline]
 do_pte_missing mm/memory.c:3689 [inline]
 handle_pte_fault mm/memory.c:5047 [inline]
 __handle_mm_fault mm/memory.c:5188 [inline]
 handle_mm_fault+0x3945/0x4a50 mm/memory.c:5353
 faultin_page mm/gup.c:868 [inline]
 __get_user_pages+0x604/0x1580 mm/gup.c:1167
 populate_vma_page_range+0x2c1/0x380 mm/gup.c:1593
 __mm_populate+0x260/0x390 mm/gup.c:1696
 mm_populate include/linux/mm.h:3383 [inline]
 vm_mmap_pgoff+0x2da/0x3f0 mm/util.c:561
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff0d779e0d9
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:00007ff0d85e1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ff0d7a25fa0 RCX: 00007ff0d779e0d9
RDX: b635773f06ebbeeb RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007ff0d7835024 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff0d7a26038 R14: 00007ff0d7a25fa0 R15: 00007ffe999d8018
 </TASK>
BUG: sleeping function called from invalid context at net/core/sock.c:3546
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 7992, name: syz.1.674
preempt_count: 102, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff81ba6c70>] folio_add_lru+0x2d0/0xce0 mm/swap.c:507
CPU: 1 PID: 7992 Comm: syz.1.674 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 __might_resched+0x48d/0x5f0 kernel/sched/core.c:10212
 lock_sock_nested+0x5d/0x100 net/core/sock.c:3546
 lock_sock include/net/sock.h:1780 [inline]
 x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782
 x25_lapb_receive_frame+0x1a7/0xef0 net/x25/x25_dev.c:138
 __netif_receive_skb_one_core net/core/dev.c:5646 [inline]
 netif_receive_skb_core+0x16a/0x230 net/core/dev.c:5671
 lapbeth_napi_poll+0x42/0x80 drivers/net/wan/lapbether.c:99
 __napi_poll+0xbb/0x460 net/core/dev.c:6650
 napi_poll net/core/dev.c:6717 [inline]
 net_rx_action+0x65f/0xcc0 net/core/dev.c:6853
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 6b 28 c4 f6 65 8b 05 cc f6 6a 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000523f4c0 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a06 RCX: f9a6e1d121d66d00
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001
RBP: ffffc9000523f550 R08: ffffffff911ed547 R09: 1ffffffff223daa8
R10: dffffc0000000000 R11: fffffbfff223daa9 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88807cdfa050 R15: 1ffff92000a47e98
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1618 [inline]
 folio_batch_move_lru+0x546/0x660 mm/swap.c:215
 folio_add_lru+0x41c/0xce0 mm/swap.c:509
 shmem_get_folio_gfp+0x1124/0x2b40 mm/shmem.c:2077
 shmem_fault+0x1b8/0x820 mm/shmem.c:2248
 __do_fault+0x13b/0x4d0 mm/memory.c:4244
 do_read_fault mm/memory.c:4638 [inline]
 do_fault mm/memory.c:4775 [inline]
 do_pte_missing mm/memory.c:3689 [inline]
 handle_pte_fault mm/memory.c:5047 [inline]
 __handle_mm_fault mm/memory.c:5188 [inline]
 handle_mm_fault+0x3945/0x4a50 mm/memory.c:5353
 faultin_page mm/gup.c:868 [inline]
 __get_user_pages+0x604/0x1580 mm/gup.c:1167
 populate_vma_page_range+0x2c1/0x380 mm/gup.c:1593
 __mm_populate+0x260/0x390 mm/gup.c:1696
 mm_populate include/linux/mm.h:3383 [inline]
 vm_mmap_pgoff+0x2da/0x3f0 mm/util.c:561
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff0d779e0d9
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:00007ff0d85e1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ff0d7a25fa0 RCX: 00007ff0d779e0d9
RDX: b635773f06ebbeeb RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007ff0d7835024 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff0d7a26038 R14: 00007ff0d7a25fa0 R15: 00007ffe999d8018
 </TASK>
----------------
Code disassembly (best guess):
   0:	c7 44 24 20 00 00 00 	movl   $0x0,0x20(%rsp)
   7:	00
   8:	9c                   	pushf
   9:	8f 44 24 20          	pop    0x20(%rsp)
   d:	f7 44 24 20 00 02 00 	testl  $0x200,0x20(%rsp)
  14:	00
  15:	41 c6 04 07 f8       	movb   $0xf8,(%r15,%rax,1)
  1a:	75 4b                	jne    0x67
  1c:	f7 c3 00 02 00 00    	test   $0x200,%ebx
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 6b 28 c4 f6       	call   0xf6c4289a <-- trapping instruction
  2f:	65 8b 05 cc f6 6a 75 	mov    %gs:0x756af6cc(%rip),%eax        # 0x756af702
  36:	85 c0                	test   %eax,%eax
  38:	74 3c                	je     0x76
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss