======================================
| [  703.410303][    C1] TCP: request_sock_TCP: Possible SYN flooding on port 127.0.0.1:23456. Sending cookies.
| [  703.589173][    C2] TCP: request_sock_TCP: Possible SYN flooding on port 127.0.0.1:23456. Sending cookies.
| [  705.582639][    C3] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [  705.583081][    C3] KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077]
[  705.583632][    C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 705.584009][ C3] RIP: 0010:__inet_csk_reqsk_queue_drop (./include/linux/list.h:958 ./include/net/sock.h:744 ./include/net/sock.h:749 net/ipv4/inet_connection_sock.c:1042 net/ipv4/inet_connection_sock.c:1058) 
[ 705.584229][ C3] Code: 00 00 00 00 00 fc ff df 41 57 4c 8d 7e 70 41 56 41 55 41 89 d5 4c 89 fa 41 54 48 c1 ea 03 55 48 89 f5 53 48 89 fb 48 83 ec 08 <80> 3c 02 00 0f 85 6c 05 00 00 45 31 e4 48 83 7d 70 00 0f 84 0f 01
All code
========
   0:	00 00                	add    %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	00 fc                	add    %bh,%ah
   6:	ff                   	(bad)
   7:	df 41 57             	filds  0x57(%rcx)
   a:	4c 8d 7e 70          	lea    0x70(%rsi),%r15
   e:	41 56                	push   %r14
  10:	41 55                	push   %r13
  12:	41 89 d5             	mov    %edx,%r13d
  15:	4c 89 fa             	mov    %r15,%rdx
  18:	41 54                	push   %r12
  1a:	48 c1 ea 03          	shr    $0x3,%rdx
  1e:	55                   	push   %rbp
  1f:	48 89 f5             	mov    %rsi,%rbp
  22:	53                   	push   %rbx
  23:	48 89 fb             	mov    %rdi,%rbx
  26:	48 83 ec 08          	sub    $0x8,%rsp
  2a:*	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)		<-- trapping instruction
  2e:	0f 85 6c 05 00 00    	jne    0x5a0
  34:	45 31 e4             	xor    %r12d,%r12d
  37:	48 83 7d 70 00       	cmpq   $0x0,0x70(%rbp)
  3c:	0f                   	.byte 0xf
  3d:	84 0f                	test   %cl,(%rdi)
  3f:	01                   	.byte 0x1

Code starting with the faulting instruction
===========================================
   0:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   4:	0f 85 6c 05 00 00    	jne    0x576
   a:	45 31 e4             	xor    %r12d,%r12d
   d:	48 83 7d 70 00       	cmpq   $0x0,0x70(%rbp)
  12:	0f                   	.byte 0xf
  13:	84 0f                	test   %cl,(%rdi)
  15:	01                   	.byte 0x1
[  705.584855][    C3] RSP: 0018:ffffc90000298c28 EFLAGS: 00010296
[  705.585070][    C3] RAX: dffffc0000000000 RBX: ffff888006a10040 RCX: 1ffff11000f4a5a7
[  705.585347][    C3] RDX: 000000000000000e RSI: 0000000000000000 RDI: ffff888006a10040
[  705.585618][    C3] RBP: 0000000000000000 R08: ffffffff8bb3fe6f R09: fffffbfff1bee809
[  705.585873][    C3] R10: ffffffff8df7404f R11: 0000000000000001 R12: 0000000000000000
[  705.586140][    C3] R13: 0000000000000001 R14: ffff888009d074e8 R15: 0000000000000070
[  705.586428][    C3] FS:  0000000000000000(0000) GS:ffff888036180000(0000) knlGS:0000000000000000
[  705.586743][    C3] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  705.586948][    C3] CR2: 00007f1921adc270 CR3: 0000000009788003 CR4: 0000000000772ef0
[  705.587211][    C3] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  705.587476][    C3] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  705.587733][    C3] PKRU: 55555554
[  705.587865][    C3] Call Trace:
[  705.587996][    C3]  <IRQ>
[ 705.588086][ C3] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 705.588239][ C3] ? exc_general_protection (arch/x86/kernel/traps.c:751 arch/x86/kernel/traps.c:693) 
[ 705.588425][ C3] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[ 705.588596][ C3] ? reuseport_migrate_sock (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/sock_reuseport.c:674) 
[ 705.588792][ C3] ? __inet_csk_reqsk_queue_drop (./include/linux/list.h:958 ./include/net/sock.h:744 ./include/net/sock.h:749 net/ipv4/inet_connection_sock.c:1042 net/ipv4/inet_connection_sock.c:1058) 
[ 705.589000][ C3] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5827) 
[ 705.589186][ C3] reqsk_timer_handler (./include/net/request_sock.h:148 net/ipv4/inet_connection_sock.c:1194) 
[ 705.589379][ C3] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5790) 
[ 705.589560][ C3] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 705.589742][ C3] ? __pfx_reqsk_timer_handler (net/ipv4/inet_connection_sock.c:1085) 
[ 705.589916][ C3] ? call_timer_fn (kernel/time/timer.c:1791) 
[ 705.590101][ C3] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 705.590291][ C3] ? __pfx_reqsk_timer_handler (net/ipv4/inet_connection_sock.c:1085) 
[ 705.590485][ C3] call_timer_fn (kernel/time/timer.c:1794) 
[ 705.590665][ C3] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1784) 
[ 705.590834][ C3] ? call_timer_fn (./include/linux/lockdep.h:31 kernel/time/timer.c:1784) 
[ 705.591011][ C3] ? __pfx_call_timer_fn (kernel/time/timer.c:1771) 
[ 705.591183][ C3] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 705.591326][ C3] __run_timers (kernel/time/timer.c:1846 kernel/time/timer.c:2419) 
[ 705.591494][ C3] ? __pfx_reqsk_timer_handler (net/ipv4/inet_connection_sock.c:1085) 
[ 705.591667][ C3] ? __pfx___run_timers (kernel/time/timer.c:2390) 
[ 705.591850][ C3] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:107 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116) 
[ 705.592021][ C3] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 705.592215][ C3] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 705.592398][ C3] ? run_timer_softirq (kernel/time/timer.c:2430 kernel/time/timer.c:2423 kernel/time/timer.c:2439 kernel/time/timer.c:2447) 
[ 705.592564][ C3] run_timer_softirq (kernel/time/timer.c:2431 kernel/time/timer.c:2423 kernel/time/timer.c:2439 kernel/time/timer.c:2447) 
[ 705.592755][ C3] handle_softirqs (kernel/softirq.c:554) 
[ 705.592925][ C3] irq_exit_rcu (kernel/softirq.c:589 kernel/softirq.c:428 kernel/softirq.c:637 kernel/softirq.c:649) 
[ 705.593068][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1037 arch/x86/kernel/apic/apic.c:1037) 
[  705.593236][    C3]  </IRQ>
[  705.593335][    C3]  <TASK>
[ 705.593436][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 705.593646][ C3] RIP: 0010:_raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:152 kernel/locking/spinlock.c:194) 
[ 705.593873][ C3] Code: 10 e8 d1 0e 88 fd 48 89 ef e8 e9 7f 88 fd 81 e3 00 02 00 00 75 1d 9c 58 f6 c4 02 75 29 48 85 db 74 01 fb 65 ff 0d 95 76 db 73 <74> 0e 5b 5d c3 cc cc cc cc e8 3f 61 b0 fd eb dc 0f 1f 44 00 00 5b
All code
========
   0:	10 e8                	adc    %ch,%al
   2:	d1 0e                	rorl   (%rsi)
   4:	88 fd                	mov    %bh,%ch
   6:	48 89 ef             	mov    %rbp,%rdi
   9:	e8 e9 7f 88 fd       	call   0xfffffffffd887ff7
   e:	81 e3 00 02 00 00    	and    $0x200,%ebx
  14:	75 1d                	jne    0x33
  16:	9c                   	pushf
  17:	58                   	pop    %rax
  18:	f6 c4 02             	test   $0x2,%ah
  1b:	75 29                	jne    0x46
  1d:	48 85 db             	test   %rbx,%rbx
  20:	74 01                	je     0x23
  22:	fb                   	sti
  23:	65 ff 0d 95 76 db 73 	decl   %gs:0x73db7695(%rip)        # 0x73db76bf
  2a:*	74 0e                	je     0x3a		<-- trapping instruction
  2c:	5b                   	pop    %rbx
  2d:	5d                   	pop    %rbp
  2e:	c3                   	ret
  2f:	cc                   	int3
  30:	cc                   	int3
  31:	cc                   	int3
  32:	cc                   	int3
  33:	e8 3f 61 b0 fd       	call   0xfffffffffdb06177
  38:	eb dc                	jmp    0x16
  3a:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  3f:	5b                   	pop    %rbx

Code starting with the faulting instruction
===========================================
   0:	74 0e                	je     0x10
   2:	5b                   	pop    %rbx
   3:	5d                   	pop    %rbp
   4:	c3                   	ret
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   8:	cc                   	int3
   9:	e8 3f 61 b0 fd       	call   0xfffffffffdb0614d
   e:	eb dc                	jmp    0xffffffffffffffec
  10:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  15:	5b                   	pop    %rbx
[  705.594514][    C3] RSP: 0018:ffffc90000f9f3a0 EFLAGS: 00000282
[  705.594736][    C3] RAX: 0000000000000006 RBX: 0000000000000200 RCX: 1ffffffff1bedf91
[  705.594991][    C3] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c285241
[  705.595265][    C3] RBP: ffff888001041080 R08: 0000000000000001 R09: 0000000000000001
[  705.595564][    C3] R10: ffffffff8df7404f R11: ffffc90000f9f1c9 R12: ffff888001041080
[  705.595816][    C3] R13: ffffea00002d5e00 R14: ffff8880010433c0 R15: ffff88800b579000
[ 705.596103][ C3] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 705.596316][ C3] get_partial_node.part.0 (mm/slub.c:2863) 
[ 705.596530][ C3] ___slab_alloc (mm/slub.c:2824 mm/slub.c:2941 mm/slub.c:3799) 
[ 705.596701][ C3] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 705.596875][ C3] ? fs_reclaim_acquire (mm/page_alloc.c:3826 mm/page_alloc.c:3816 mm/page_alloc.c:3846) 
[ 705.597084][ C3] ? p9_fcall_init (net/9p/client.c:233) 
[ 705.597251][ C3] ? lock_downgrade (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5729) 
[ 705.597453][ C3] ? p9_fcall_init (net/9p/client.c:233) 
[ 705.597628][ C3] ? __kmalloc_noprof (mm/slub.c:3909 mm/slub.c:3962 mm/slub.c:4123 mm/slub.c:4264 mm/slub.c:4277) 
[ 705.597952][ C3] __kmalloc_noprof (mm/slub.c:3909 mm/slub.c:3962 mm/slub.c:4123 mm/slub.c:4264 mm/slub.c:4277) 
[ 705.598130][ C3] p9_fcall_init (net/9p/client.c:233) 
[ 705.598312][ C3] p9_tag_alloc (net/9p/client.c:300) 
[ 705.598486][ C3] ? __pfx_p9_tag_alloc (net/9p/client.c:280) 
[ 705.598780][ C3] ? __pfx_i_callback (fs/inode.c:249) 
[ 705.598983][ C3] ? kasan_save_stack (mm/kasan/common.c:49) 
[ 705.599164][ C3] ? kasan_save_stack (mm/kasan/common.c:48) 
[ 705.599328][ C3] p9_client_prepare_req (net/9p/client.c:644) 
[ 705.599599][ C3] ? vfs_statx (fs/stat.c:313) 
[ 705.599727][ C3] ? vfs_fstatat (fs/stat.c:342) 
[ 705.599896][ C3] ? __pfx_p9_client_prepare_req (net/9p/client.c:628) 
[ 705.600113][ C3] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860) 
[ 705.600378][ C3] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:228) 
[ 705.600587][ C3] ? mark_lock (kernel/locking/lockdep.c:4703 (discriminator 3)) 
[ 705.600715][ C3] p9_client_rpc (net/9p/client.c:691 (discriminator 4)) 
[ 705.601014][ C3] ? __pfx_p9_client_rpc (net/9p/client.c:675) 
[ 705.601205][ C3] ? find_held_lock (kernel/locking/lockdep.c:5315) 
[ 705.601485][ C3] ? v9fs_dentry_release (fs/9p/vfs_dentry.c:60) 
[ 705.601666][ C3] ? __pfx___lock_release (kernel/locking/lockdep.c:5477) 
[ 705.601847][ C3] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5790) 
[ 705.602017][ C3] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:107 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116) 
[ 705.602324][ C3] p9_client_clunk (net/9p/client.c:1441 (discriminator 3)) 
[ 705.602497][ C3] v9fs_dentry_release (fs/9p/vfs_dentry.c:60) 
[ 705.602681][ C3] ? __pfx_v9fs_dentry_release (fs/9p/vfs_dentry.c:49) 
[ 705.602976][ C3] ? _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 705.603199][ C3] ? iput_final (fs/inode.c:1875) 
[ 705.603367][ C3] __dentry_kill (fs/dcache.c:620) 
[ 705.603550][ C3] ? __pfx_kfree_link (fs/libfs.c:1628) 
[ 705.603835][ C3] dput.part.0 (fs/dcache.c:857) 
[ 705.604002][ C3] walk_component (fs/namei.c:569 fs/namei.c:1034 fs/namei.c:2058) 
[ 705.604306][ C3] link_path_walk.part.0.constprop.0 (fs/namei.c:2420) 
[ 705.604513][ C3] ? path_init (fs/namei.c:2484) 
[ 705.604682][ C3] ? __pfx_link_path_walk.part.0.constprop.0 (fs/namei.c:2343) 
[ 705.604994][ C3] path_lookupat (fs/namei.c:2348 (discriminator 2) fs/namei.c:2579 (discriminator 2)) 
[ 705.605170][ C3] filename_lookup (fs/namei.c:2610) 
[ 705.605339][ C3] ? __pfx_filename_lookup (fs/namei.c:2603) 
[ 705.605508][ C3] ? __pfx_kfree_link (fs/libfs.c:1628) 
[ 705.605674][ C3] ? __lock_release (kernel/locking/lockdep.c:5501) 
[ 705.605932][ C3] ? __pfx___lock_release (kernel/locking/lockdep.c:5477) 
[ 705.606096][ C3] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 705.606262][ C3] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 705.606430][ C3] ? lock_acquire (kernel/locking/lockdep.c:5798) 
[ 705.606600][ C3] ? __might_fault (mm/memory.c:6700 mm/memory.c:6693) 
[ 705.606764][ C3] vfs_statx (fs/stat.c:313) 
[ 705.606887][ C3] ? __pfx_vfs_statx (fs/stat.c:302) 
[ 705.607053][ C3] ? getname_flags.part.0 (./include/linux/audit.h:369 fs/namei.c:210) 
[ 705.607313][ C3] vfs_fstatat (fs/stat.c:342) 
[ 705.607438][ C3] __do_sys_newfstatat (fs/stat.c:506) 
[ 705.607603][ C3] ? __pfx___do_sys_newfstatat (fs/stat.c:501) 
[ 705.607781][ C3] ? trace_kfree (./include/trace/events/kmem.h:94 (discriminator 52)) 
[ 705.607946][ C3] ? kfree (mm/slub.c:4717) 
[ 705.608167][ C3] ? audit_reset_context.part.0.constprop.0 (./include/linux/list.h:373 kernel/auditsc.c:1023) 
[ 705.608373][ C3] ? __pfx___x64_sys_openat (fs/open.c:1441) 
[ 705.608540][ C3] ? syscall_trace_enter (./include/linux/audit.h:349 kernel/entry/common.c:24 kernel/entry/common.c:69) 
[ 705.608706][ C3] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[ 705.608963][ C3] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[  705.609165][    C3] RIP: 0033:0x7f1921b0feae
[ 705.609435][ C3] Code: 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 07 00 00 00 0f 1f 80 00 00 00 00 f3 0f 1e fa 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 0b 31 c0 c3 0f 1f 84 00 00 00 00 00 f7 d8 89 05
All code
========
   0:	48 89 f2             	mov    %rsi,%rdx
   3:	b9 00 01 00 00       	mov    $0x100,%ecx
   8:	48 89 fe             	mov    %rdi,%rsi
   b:	bf 9c ff ff ff       	mov    $0xffffff9c,%edi
  10:	e9 07 00 00 00       	jmp    0x1c
  15:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  1c:	f3 0f 1e fa          	endbr64
  20:	41 89 ca             	mov    %ecx,%r10d
  23:	b8 06 01 00 00       	mov    $0x106,%eax
  28:	0f 05                	syscall
  2a:*	3d 00 f0 ff ff       	cmp    $0xfffff000,%eax		<-- trapping instruction
  2f:	77 0b                	ja     0x3c
  31:	31 c0                	xor    %eax,%eax
  33:	c3                   	ret
  34:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
  3b:	00 
  3c:	f7 d8                	neg    %eax
  3e:	89                   	.byte 0x89
  3f:	05                   	.byte 0x5

Code starting with the faulting instruction
===========================================
   0:	3d 00 f0 ff ff       	cmp    $0xfffff000,%eax
   5:	77 0b                	ja     0x12
   7:	31 c0                	xor    %eax,%eax
   9:	c3                   	ret
   a:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
  11:	00 
  12:	f7 d8                	neg    %eax
  14:	89                   	.byte 0x89
  15:	05                   	.byte 0x5
[  705.610118][    C3] RSP: 002b:00007ffdc1a1d848 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
[  705.610403][    C3] RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f1921b0feae
[  705.610756][    C3] RDX: 00007ffdc1a1d910 RSI: 00007ffdc1a1d850 RDI: 00000000ffffff9c
[  705.611034][    C3] RBP: 00007ffdc1a1d9d0 R08: 00000000ffffffff R09: 00007ffdc1a1d850
[  705.611296][    C3] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdc1a1d857


Finger prints:
__inet_csk_reqsk_queue_drop:reqsk_timer_handler:call_timer_fn:__run_timers:run_timer_softirq