================================
WARNING: inconsistent lock state
syzkaller #0 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffff888025efe260 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
ffff888025efe260 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x168/0x280 net/x25/af_x25.c:1778
{SOFTIRQ-ON-W} state was registered at:
  lock_acquire kernel/locking/lockdep.c:5942 [inline]
  lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
  lock_sock_nested+0x41/0xf0 net/core/sock.c:3837
  lock_sock include/net/sock.h:1713 [inline]
  x25_bind+0x221/0x5c0 net/x25/af_x25.c:694
  __sys_bind_socket net/socket.c:1945 [inline]
  __sys_bind_socket net/socket.c:1937 [inline]
  __sys_bind+0x1a9/0x260 net/socket.c:1976
  __do_sys_bind net/socket.c:1981 [inline]
  __se_sys_bind net/socket.c:1979 [inline]
  __x64_sys_bind+0x72/0xb0 net/socket.c:1979
  do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
  do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
  entry_SYSCALL_64_after_hwframe+0x77/0x7f
irq event stamp: 795156
hardirqs last  enabled at (795156): [<ffffffff81ca5245>] __local_bh_enable_ip+0xa5/0x120 kernel/softirq.c:478
hardirqs last disabled at (795155): [<ffffffff81ca526e>] __local_bh_enable_ip+0xce/0x120 kernel/softirq.c:455
softirqs last  enabled at (794802): [<ffffffff81ca4caa>] __do_softirq kernel/softirq.c:679 [inline]
softirqs last  enabled at (794802): [<ffffffff81ca4caa>] invoke_softirq kernel/softirq.c:519 [inline]
softirqs last  enabled at (794802): [<ffffffff81ca4caa>] __irq_exit_rcu+0x16a/0x210 kernel/softirq.c:758
softirqs last disabled at (794809): [<ffffffff81ca4caa>] __do_softirq kernel/softirq.c:679 [inline]
softirqs last disabled at (794809): [<ffffffff81ca4caa>] invoke_softirq kernel/softirq.c:519 [inline]
softirqs last disabled at (794809): [<ffffffff81ca4caa>] __irq_exit_rcu+0x16a/0x210 kernel/softirq.c:758

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 swapper/1/0: 1, last CPU#1:
 #0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8edec5a0 (rcu_read_lock){....}-{1:3}, at: netif_receive_skb_core+0x25/0x1a0 net/core/dev.c:6321

stack backtrace:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_usage_bug.part.0+0x258/0x340 kernel/locking/lockdep.c:4086
 print_usage_bug kernel/locking/lockdep.c:4054 [inline]
 valid_state kernel/locking/lockdep.c:4100 [inline]
 mark_lock_irq kernel/locking/lockdep.c:4311 [inline]
 mark_lock+0x956/0x1020 kernel/locking/lockdep.c:4797
 mark_usage kernel/locking/lockdep.c:4686 [inline]
 __lock_acquire+0x7f1/0x1f40 kernel/locking/lockdep.c:5242
 lock_acquire kernel/locking/lockdep.c:5942 [inline]
 lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
 lock_sock_nested+0x41/0xf0 net/core/sock.c:3837
 lock_sock include/net/sock.h:1713 [inline]
 x25_kill_by_neigh+0x168/0x280 net/x25/af_x25.c:1778
 x25_lapb_receive_frame+0x4b1/0x1000 net/x25/x25_dev.c:138
 __netif_receive_skb_one_core+0x1b2/0x1e0 net/core/dev.c:6297
 netif_receive_skb_core+0x5a/0x1a0 net/core/dev.c:6322
 lapbeth_napi_poll+0x42/0xc0 drivers/net/wan/lapbether.c:100
 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7830
 napi_poll net/core/dev.c:7893 [inline]
 net_rx_action+0xa40/0xf20 net/core/dev.c:8050
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0x16a/0x210 kernel/softirq.c:758
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: f7 92 02 e9 53 50 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 53 d8 18 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000187e00 EFLAGS: 00000206
RAX: 00000000000c20b7 RBX: ffff88801f2d4b00 RCX: ffffffff8bd2e235
RDX: 0000000000000001 RSI: ffffffff8e38f5e4 RDI: ffffffff8c623a80
RBP: ffffed1003e5a960 R08: 0000000000000001 R09: ffffed100d4a67bd
R10: ffff88806a533deb R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000030fc4 R15: dffffc0000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:768
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x158
 </TASK>
BUG: sleeping function called from invalid context at net/core/sock.c:3839
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/1
preempt_count: 101, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 __might_resched.cold+0x1dc/0x222 kernel/sched/core.c:9264
 lock_sock_nested+0x52/0xf0 net/core/sock.c:3839
 lock_sock include/net/sock.h:1713 [inline]
 x25_kill_by_neigh+0x168/0x280 net/x25/af_x25.c:1778
 x25_lapb_receive_frame+0x4b1/0x1000 net/x25/x25_dev.c:138
 __netif_receive_skb_one_core+0x1b2/0x1e0 net/core/dev.c:6297
 netif_receive_skb_core+0x5a/0x1a0 net/core/dev.c:6322
 lapbeth_napi_poll+0x42/0xc0 drivers/net/wan/lapbether.c:100
 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7830
 napi_poll net/core/dev.c:7893 [inline]
 net_rx_action+0xa40/0xf20 net/core/dev.c:8050
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 __do_softirq kernel/softirq.c:679 [inline]
 invoke_softirq kernel/softirq.c:519 [inline]
 __irq_exit_rcu+0x16a/0x210 kernel/softirq.c:758
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: f7 92 02 e9 53 50 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 53 d8 18 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000187e00 EFLAGS: 00000206
RAX: 00000000000c20b7 RBX: ffff88801f2d4b00 RCX: ffffffff8bd2e235
RDX: 0000000000000001 RSI: ffffffff8e38f5e4 RDI: ffffffff8c623a80
RBP: ffffed1003e5a960 R08: 0000000000000001 R09: ffffed100d4a67bd
R10: ffff88806a533deb R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 1ffff92000030fc4 R15: dffffc0000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:768
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x3ae/0x5b0 kernel/sched/idle.c:355
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x158
 </TASK>
----------------
Code disassembly (best guess):
   0:	f7 92 02 e9 53 50    	notl   0x5053e902(%rdx)
   6:	03 00                	add    (%rax),%eax
   8:	0f 1f 00             	nopl   (%rax)
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	eb 07                	jmp    0x28
  21:	0f 00 2d 53 d8 18 00 	verw   0x18d853(%rip)        # 0x18d87b
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	c3                   	ret <-- trapping instruction
  2b:	cc                   	int3
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  36:	00 00 00
  39:	66 90                	xchg   %ax,%ax
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop