------------[ cut here ]------------
sk->sk_forward_alloc
WARNING: net/ipv4/af_inet.c:162 at inet_sock_destruct+0x653/0x800 net/ipv4/af_inet.c:162, CPU#3: swapper/3/0
Modules linked in:
CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:inet_sock_destruct+0x653/0x800 net/ipv4/af_inet.c:162
Code: 4e 4d ff e9 06 fd ff ff e8 5a 6d fd f7 90 0f 0b 90 e9 35 fe ff ff e8 4c 6d fd f7 90 0f 0b 90 e9 c5 fe ff ff e8 3e 6d fd f7 90 <0f> 0b 90 e9 04 ff ff ff e8 30 6d fd f7 90 0f 0b 90 e9 65 fe ff ff
RSP: 0018:ffffc900006f8d88 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888039a05d80 RCX: ffffffff8a0b43a7
RDX: ffff88801ee92500 RSI: ffffffff8a0b44a2 RDI: ffff88801ee92500
RBP: 0000000000000090 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000090 R11: 000000000000a9e2 R12: ffff888039a05d80
R13: ffff888039a05e10 R14: ffffffff81ee357d R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880d666a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9f41be5fa8 CR3: 000000000e596000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 __sk_destruct+0x85/0xab0 net/core/sock.c:2352
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 56 92 02 c3 cc cc cc cc 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 43 41 20 00 fb f4 <e9> 7c 42 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000202
RAX: 00000000001687c1 RBX: ffff88801ee92500 RCX: ffffffff8b8b50b5
RDX: 0000000000000000 RSI: ffffffff8df24460 RDI: ffffffff8c1c4500
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed100d4e67b5
R10: ffff88806a733dab R11: 0000000000000000 R12: 0000000000000003
R13: ffffed1003dd24a0 R14: 0000000000000003 R15: ffffffff90d7e950
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x464/0x590 kernel/sched/idle.c:352
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>
----------------
Code disassembly (best guess):
   0:	56                   	push   %rsi
   1:	92                   	xchg   %eax,%edx
   2:	02 c3                	add    %bl,%al
   4:	cc                   	int3
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   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 43 41 20 00 	verw   0x204143(%rip)        # 0x20416b
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	e9 7c 42 03 00       	jmp    0x342ab <-- trapping instruction
  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