======================================
| [ 4555.630827][    C2] ==================================================================
| [ 4555.631120][ C2] BUG: KASAN: null-ptr-deref in sock_def_write_space_wfree (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 net/core/sock.c:3397) 
| [ 4555.631324][    C2] Read of size 8 at addr 0000000000000008 by task swapper/2/0
| [ 4555.631518][    C2]
[ 4555.631785][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 4555.632073][    C2] Call Trace:
[ 4555.632174][    C2]  <IRQ>
[ 4555.632243][ C2] dump_stack_lvl (lib/dump_stack.c:117) 
[ 4555.632384][ C2] kasan_report (mm/kasan/report.c:603) 
[ 4555.632484][ C2] ? sock_def_write_space_wfree (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 net/core/sock.c:3397) 
[ 4555.632652][ C2] kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) 
[ 4555.632784][ C2] sock_def_write_space_wfree (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 net/core/sock.c:3397) 
[ 4555.632918][ C2] sock_wfree (./include/linux/rcupdate.h:810 net/core/sock.c:2471) 
[ 4555.633020][ C2] ip6_rcv_core (./include/linux/skbuff.h:3202 net/ipv6/ip6_input.c:291) 
[ 4555.633155][ C2] ipv6_rcv (net/ipv6/ip6_input.c:307) 
[ 4555.633253][ C2] ? __pfx_ipv6_rcv (net/ipv6/ip6_input.c:304) 
[ 4555.633385][ C2] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 4555.633516][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6046) 
[ 4555.633649][ C2] ? __pfx_ipv6_rcv (net/ipv6/ip6_input.c:304) 
[ 4555.633777][ C2] __netif_receive_skb_one_core (net/core/dev.c:5597) 
[ 4555.633943][ C2] ? __pfx___netif_receive_skb_one_core (net/core/dev.c:5597) 
[ 4555.634104][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6046) 
[ 4555.634236][ C2] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 4555.634367][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6046) 
[ 4555.634498][ C2] process_backlog (./include/linux/rcupdate.h:810 net/core/dev.c:6048) 
[ 4555.634630][ C2] __napi_poll.constprop.0 (net/core/dev.c:6701) 
[ 4555.634762][ C2] net_rx_action (net/core/dev.c:6770 net/core/dev.c:6886) 
[ 4555.634899][ C2] ? __pfx_net_rx_action (net/core/dev.c:6850) 
[ 4555.635032][ C2] __do_softirq (kernel/softirq.c:554) 
[ 4555.635165][ C2] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 4555.635265][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[ 4555.635398][    C2]  </IRQ>
[ 4555.635468][    C2]  <TASK>
[ 4555.635535][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 4555.635697][ C2] RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:72 arch/x86/kernel/process.c:743) 
[ 4555.635835][ C2] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a3 dc 32 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
All code
========
   0:	4c 01 c7             	add    %r8,%rdi
   3:	4c 29 c2             	sub    %r8,%rdx
   6:	e9 72 ff ff ff       	jmp    0xffffffffffffff7d
   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:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d a3 dc 32 00 	verw   0x32dca3(%rip)        # 0x32dccb
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	fa                   	cli		<-- trapping instruction
  2b:	c3                   	ret
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	cc                   	int3
  30:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
  37:	00 00 00 00 
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Code starting with the faulting instruction
===========================================
   0:	fa                   	cli
   1:	c3                   	ret
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	cc                   	int3
   6:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
   d:	00 00 00 00 
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
[ 4555.636300][    C2] RSP: 0018:ffffc9000015fdf8 EFLAGS: 00000246
[ 4555.636468][    C2] RAX: 00000000046137ed RBX: 1ffff9200002bfc1 RCX: ffffffffa6133ed5
[ 4555.636664][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa38ac0e4
[ 4555.636856][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c2709c
[ 4555.637050][    C2] R10: ffff8880361384e3 R11: ffff88803612d9b0 R12: 0000000000000000
[ 4555.637248][    C2] R13: ffff888001b8c5c0 R14: dffffc0000000000 R15: 0000000000000000
[ 4555.637446][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 4555.637576][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 4555.637707][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 4555.637835][ C2] cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 4555.637966][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 4555.638096][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 4555.638231][ C2] do_idle (kernel/sched/idle.c:332) 
[ 4555.638330][ C2] cpu_startup_entry (kernel/sched/idle.c:429 (discriminator 1)) 
[ 4555.638461][ C2] start_secondary (arch/x86/kernel/smpboot.c:201 arch/x86/kernel/smpboot.c:281) 
[ 4555.638590][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:231) 
[ 4555.638720][ C2] common_startup_64 (arch/x86/kernel/head_64.S:421) 
| [ 4555.638950][    C2] ==================================================================
| [ 4555.639140][    C2] Disabling lock debugging due to kernel taint
| [ 4555.639327][    C2] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [ 4555.639609][    C2] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
[ 4555.640027][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 4555.640315][ C2] RIP: 0010:sock_def_write_space_wfree (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 net/core/sock.c:3397) 
[ 4555.640478][ C2] Code: 00 4c 8b bb a0 01 00 00 be 08 00 00 00 4d 8d 77 08 4c 89 f7 e8 e0 0e 8b fe 4c 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 fe 00 00 00 49 8b 47 08 a8 04 0f 85 dc fe ff ff
All code
========
   0:	00 4c 8b bb          	add    %cl,-0x45(%rbx,%rcx,4)
   4:	a0 01 00 00 be 08 00 	movabs 0x8be000001,%al
   b:	00 00 
   d:	4d 8d 77 08          	lea    0x8(%r15),%r14
  11:	4c 89 f7             	mov    %r14,%rdi
  14:	e8 e0 0e 8b fe       	call   0xfffffffffe8b0ef9
  19:	4c 89 f2             	mov    %r14,%rdx
  1c:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  23:	fc ff df 
  26:	48 c1 ea 03          	shr    $0x3,%rdx
  2a:*	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)		<-- trapping instruction
  2e:	0f 85 fe 00 00 00    	jne    0x132
  34:	49 8b 47 08          	mov    0x8(%r15),%rax
  38:	a8 04                	test   $0x4,%al
  3a:	0f 85 dc fe ff ff    	jne    0xffffffffffffff1c

Code starting with the faulting instruction
===========================================
   0:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   4:	0f 85 fe 00 00 00    	jne    0x108
   a:	49 8b 47 08          	mov    0x8(%r15),%rax
   e:	a8 04                	test   $0x4,%al
  10:	0f 85 dc fe ff ff    	jne    0xfffffffffffffef2
[ 4555.640926][    C2] RSP: 0018:ffffc90000230b28 EFLAGS: 00010202
[ 4555.641090][    C2] RAX: dffffc0000000000 RBX: ffff8880090f0040 RCX: ffffffffa379564a
[ 4555.641281][    C2] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffffa8cfda00
[ 4555.641470][    C2] RBP: ffff8880090f00a0 R08: 0000000000000001 R09: fffffbfff519fb40
[ 4555.641660][    C2] R10: ffffffffa8cfda07 R11: 205d324320202020 R12: 0000000000000000
[ 4555.641850][    C2] R13: ffff8880090f01c0 R14: 0000000000000008 R15: 0000000000000000
[ 4555.642042][    C2] FS:  0000000000000000(0000) GS:ffff888036100000(0000) knlGS:0000000000000000
[ 4555.642264][    C2] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4555.642424][    C2] CR2: 00007fc7d77c8270 CR3: 0000000008fd0002 CR4: 0000000000770ef0
[ 4555.642617][    C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 4555.642806][    C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 4555.642997][    C2] PKRU: 55555554
[ 4555.643094][    C2] Call Trace:
[ 4555.643191][    C2]  <IRQ>
[ 4555.643258][ C2] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 4555.643356][ C2] ? exc_general_protection (arch/x86/kernel/traps.c:702 arch/x86/kernel/traps.c:644) 
[ 4555.643486][ C2] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[ 4555.643614][ C2] ? add_taint (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 kernel/panic.c:555) 
[ 4555.643712][ C2] ? sock_def_write_space_wfree (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 net/core/sock.c:3397) 
[ 4555.643871][ C2] ? sock_def_write_space_wfree (./arch/x86/include/asm/bitops.h:206 ./arch/x86/include/asm/bitops.h:238 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 net/core/sock.c:3397) 
[ 4555.644033][ C2] sock_wfree (./include/linux/rcupdate.h:810 net/core/sock.c:2471) 
[ 4555.644131][ C2] ip6_rcv_core (./include/linux/skbuff.h:3202 net/ipv6/ip6_input.c:291) 
[ 4555.644261][ C2] ipv6_rcv (net/ipv6/ip6_input.c:307) 
[ 4555.644357][ C2] ? __pfx_ipv6_rcv (net/ipv6/ip6_input.c:304) 
[ 4555.644486][ C2] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 4555.644613][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6046) 
[ 4555.644741][ C2] ? __pfx_ipv6_rcv (net/ipv6/ip6_input.c:304) 
[ 4555.644868][ C2] __netif_receive_skb_one_core (net/core/dev.c:5597) 
[ 4555.645028][ C2] ? __pfx___netif_receive_skb_one_core (net/core/dev.c:5597) 
[ 4555.645186][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6046) 
[ 4555.645315][ C2] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 4555.645442][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6046) 
[ 4555.645570][ C2] process_backlog (./include/linux/rcupdate.h:810 net/core/dev.c:6048) 
[ 4555.645700][ C2] __napi_poll.constprop.0 (net/core/dev.c:6701) 
[ 4555.645829][ C2] net_rx_action (net/core/dev.c:6770 net/core/dev.c:6886) 
[ 4555.645960][ C2] ? __pfx_net_rx_action (net/core/dev.c:6850) 
[ 4555.646093][ C2] __do_softirq (kernel/softirq.c:554) 
[ 4555.646221][ C2] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 4555.646319][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[ 4555.646448][    C2]  </IRQ>
[ 4555.646513][    C2]  <TASK>
[ 4555.646577][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 4555.646734][ C2] RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:72 arch/x86/kernel/process.c:743) 
[ 4555.646866][ C2] Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d a3 dc 32 00 fb f4 <fa> c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
All code
========
   0:	4c 01 c7             	add    %r8,%rdi
   3:	4c 29 c2             	sub    %r8,%rdx
   6:	e9 72 ff ff ff       	jmp    0xffffffffffffff7d
   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:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d a3 dc 32 00 	verw   0x32dca3(%rip)        # 0x32dccb
  28:	fb                   	sti
  29:	f4                   	hlt
  2a:*	fa                   	cli		<-- trapping instruction
  2b:	c3                   	ret
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	cc                   	int3
  30:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
  37:	00 00 00 00 
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop

Code starting with the faulting instruction
===========================================
   0:	fa                   	cli
   1:	c3                   	ret
   2:	cc                   	int3
   3:	cc                   	int3
   4:	cc                   	int3
   5:	cc                   	int3
   6:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
   d:	00 00 00 00 
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
[ 4555.647317][    C2] RSP: 0018:ffffc9000015fdf8 EFLAGS: 00000246
[ 4555.647477][    C2] RAX: 00000000046137ed RBX: 1ffff9200002bfc1 RCX: ffffffffa6133ed5
[ 4555.647667][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa38ac0e4
[ 4555.647858][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c2709c
[ 4555.648051][    C2] R10: ffff8880361384e3 R11: ffff88803612d9b0 R12: 0000000000000000
[ 4555.648242][    C2] R13: ffff888001b8c5c0 R14: dffffc0000000000 R15: 0000000000000000
[ 4555.648434][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 4555.648562][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 4555.648690][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 4555.648816][ C2] cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 4555.648944][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 4555.649074][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 4555.649202][ C2] do_idle (kernel/sched/idle.c:332) 
[ 4555.649300][ C2] cpu_startup_entry (kernel/sched/idle.c:429 (discriminator 1)) 
[ 4555.649427][ C2] start_secondary (arch/x86/kernel/smpboot.c:201 arch/x86/kernel/smpboot.c:281) 
[ 4555.649555][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:231) 


Finger prints:
dump_stack_lvl:kasan_report:kasan_check_range:sock_def_write_space_wfree
sock_def_write_space_wfree:sock_wfree:ip6_rcv_core:ipv6_rcv