------------[ cut here ]------------
sk->sk_forward_alloc
WARNING: net/ipv4/af_inet.c:163 at inet_sock_destruct+0x653/0x800 net/ipv4/af_inet.c:163, CPU#0: kworker/0:1/10
Modules linked in:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 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
Workqueue:  0x0 (sock_diag_events)
RIP: 0010:inet_sock_destruct+0x653/0x800 net/ipv4/af_inet.c:163
Code: f1 4e ff e9 06 fd ff ff e8 aa 8a ff f7 90 0f 0b 90 e9 35 fe ff ff e8 9c 8a ff f7 90 0f 0b 90 e9 c5 fe ff ff e8 8e 8a ff f7 90 <0f> 0b 90 e9 04 ff ff ff e8 80 8a ff f7 90 0f 0b 90 e9 65 fe ff ff
RSP: 0018:ffffc90000007d98 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888021ee9980 RCX: ffffffff8a095477
RDX: ffff88801e6a24c0 RSI: ffffffff8a095572 RDI: ffff88801e6a24c0
RBP: 0000000000000f70 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000f70 R11: 000000000000761b R12: ffff888021ee9980
R13: ffff888021ee9a10 R14: ffffffff81eea5bd R15: 0000000000000005
FS:  0000000000000000(0000) GS:ffff8880d633f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4a59d4ff8 CR3: 000000005b6a8000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 __sk_destruct+0x85/0xbb0 net/core/sock.c:2350
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch.isra.0+0x20e/0xb80 kernel/sched/core.c:5155
Code: 86 03 0f 48 85 d2 0f 85 84 06 00 00 85 c0 0f 85 a7 01 00 00 48 89 df e8 20 e5 ff ff e8 9b 8e 3a 00 fb 49 8d bc 24 80 16 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84
RSP: 0018:ffffc900000d7bd0 EFLAGS: 00000206
RAX: 000000000001be47 RBX: ffff88806a43b140 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8de782ff RDI: ffff88801e6a3b40
RBP: ffffc900000d7c18 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801e6a24c0
R13: ffff88802bf98000 R14: ffff88802bf98000 R15: ffff88806a43bf80
 context_switch kernel/sched/core.c:5301 [inline]
 __schedule+0xff6/0x6120 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7008
 worker_thread+0x53b/0xe50 kernel/workqueue.c:3455
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	03 0f                	add    (%rdi),%ecx
   2:	48 85 d2             	test   %rdx,%rdx
   5:	0f 85 84 06 00 00    	jne    0x68f
   b:	85 c0                	test   %eax,%eax
   d:	0f 85 a7 01 00 00    	jne    0x1ba
  13:	48 89 df             	mov    %rbx,%rdi
  16:	e8 20 e5 ff ff       	call   0xffffe53b
  1b:	e8 9b 8e 3a 00       	call   0x3a8ebb
  20:	fb                   	sti
  21:	49 8d bc 24 80 16 00 	lea    0x1680(%r12),%rdi
  28:	00
* 29:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax <-- trapping instruction
  30:	fc ff df
  33:	48 89 fa             	mov    %rdi,%rdx
  36:	48 c1 ea 03          	shr    $0x3,%rdx
  3a:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax
  3e:	84                   	.byte 0x84