======================================
| [ 4593.733827][    C2] ==================================================================
| [ 4593.734134][ 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:3399) 
| [ 4593.734341][    C2] Read of size 8 at addr 0000000000000008 by task swapper/2/0
| [ 4593.734535][    C2]
[ 4593.734808][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 4593.735091][    C2] Call Trace:
[ 4593.735189][    C2]  <IRQ>
[ 4593.735257][ C2] dump_stack_lvl (lib/dump_stack.c:117) 
[ 4593.735393][ C2] kasan_report (mm/kasan/report.c:603) 
[ 4593.735492][ 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:3399) 
[ 4593.735653][ C2] kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) 
[ 4593.735779][ 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:3399) 
[ 4593.735906][ C2] sock_wfree (./include/linux/rcupdate.h:810 net/core/sock.c:2471) 
[ 4593.736003][ C2] ip6_rcv_core (./include/linux/skbuff.h:3202 net/ipv6/ip6_input.c:291) 
[ 4593.736132][ C2] ipv6_rcv (net/ipv6/ip6_input.c:307) 
[ 4593.736230][ C2] ? __pfx_ipv6_rcv (net/ipv6/ip6_input.c:304) 
[ 4593.736365][ C2] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 4593.736492][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6047) 
[ 4593.736623][ C2] ? __pfx_ipv6_rcv (net/ipv6/ip6_input.c:304) 
[ 4593.736749][ C2] __netif_receive_skb_one_core (net/core/dev.c:5598) 
[ 4593.736907][ C2] ? __pfx___netif_receive_skb_one_core (net/core/dev.c:5598) 
[ 4593.737065][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6047) 
[ 4593.737193][ C2] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 4593.737319][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6047) 
[ 4593.737448][ C2] process_backlog (./include/linux/rcupdate.h:810 net/core/dev.c:6049) 
[ 4593.737575][ C2] ? __lock_release (kernel/locking/lockdep.c:5430) 
[ 4593.737703][ C2] ? rebalance_domains (./include/linux/rcupdate.h:339 ./include/linux/rcupdate.h:814 kernel/sched/fair.c:11753) 
[ 4593.737834][ C2] __napi_poll.constprop.0 (net/core/dev.c:6702) 
[ 4593.737962][ C2] net_rx_action (net/core/dev.c:6771 net/core/dev.c:6887) 
[ 4593.738092][ C2] ? __pfx_net_rx_action (net/core/dev.c:6851) 
[ 4593.738220][ C2] ? __pfx_tmigr_handle_remote (kernel/time/timer_migration.c:1026) 
[ 4593.738351][ C2] ? spin_bug (./include/linux/pid.h:232 kernel/locking/spinlock_debug.c:64 kernel/locking/spinlock_debug.c:78) 
[ 4593.738449][ C2] ? __pfx_rebalance_domains (kernel/sched/fair.c:11684) 
[ 4593.738580][ C2] __do_softirq (kernel/softirq.c:554) 
[ 4593.738710][ C2] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 4593.738808][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[ 4593.738934][    C2]  </IRQ>
[ 4593.739000][    C2]  <TASK>
[ 4593.739063][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 4593.739221][ 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) 
[ 4593.739359][ 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 e3 bc 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 e3 bc 32 00 	verw   0x32bce3(%rip)        # 0x32bd0b
  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
[ 4593.739803][    C2] RSP: 0018:ffffc9000015fdf8 EFLAGS: 00000242
[ 4593.739966][    C2] RAX: 0000000004809f01 RBX: 1ffff9200002bfc1 RCX: ffffffff94d35e95
[ 4593.740154][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff924ac0e4
[ 4593.740347][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c2709c
[ 4593.740534][    C2] R10: ffff8880361384e3 R11: ffff88803612d9b0 R12: 0000000000000000
[ 4593.740722][    C2] R13: ffff888001b8c5c0 R14: dffffc0000000000 R15: 0000000000000000
[ 4593.740910][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 4593.741036][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 4593.741167][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 4593.741291][ C2] cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 4593.741417][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 4593.741543][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 4593.741670][ C2] do_idle (kernel/sched/idle.c:332) 
[ 4593.741765][ C2] cpu_startup_entry (kernel/sched/idle.c:429 (discriminator 1)) 
[ 4593.741891][ C2] start_secondary (arch/x86/kernel/smpboot.c:201 arch/x86/kernel/smpboot.c:281) 
[ 4593.742018][ C2] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:231) 
[ 4593.742146][ C2] common_startup_64 (arch/x86/kernel/head_64.S:421) 
| [ 4593.742369][    C2] ==================================================================
| [ 4593.742553][    C2] Disabling lock debugging due to kernel taint
| [ 4593.742740][    C2] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [ 4593.743013][    C2] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
[ 4593.743414][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 4593.743689][ 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:3399) 
[ 4593.743848][ C2] Code: 00 4c 8b b3 a0 01 00 00 be 08 00 00 00 4d 8d 7e 08 4c 89 ff e8 b0 0b 8b fe 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 1e 01 00 00 49 8b 46 08 a8 04 0f 84 5c fe ff ff
All code
========
   0:	00 4c 8b b3          	add    %cl,-0x4d(%rbx,%rcx,4)
   4:	a0 01 00 00 be 08 00 	movabs 0x8be000001,%al
   b:	00 00 
   d:	4d 8d 7e 08          	lea    0x8(%r14),%r15
  11:	4c 89 ff             	mov    %r15,%rdi
  14:	e8 b0 0b 8b fe       	call   0xfffffffffe8b0bc9
  19:	4c 89 fa             	mov    %r15,%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 1e 01 00 00    	jne    0x152
  34:	49 8b 46 08          	mov    0x8(%r14),%rax
  38:	a8 04                	test   $0x4,%al
  3a:	0f 84 5c fe ff ff    	je     0xfffffffffffffe9c

Code starting with the faulting instruction
===========================================
   0:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   4:	0f 85 1e 01 00 00    	jne    0x128
   a:	49 8b 46 08          	mov    0x8(%r14),%rax
   e:	a8 04                	test   $0x4,%al
  10:	0f 84 5c fe ff ff    	je     0xfffffffffffffe72
[ 4593.744286][    C2] RSP: 0018:ffffc90000230b28 EFLAGS: 00010202
[ 4593.744442][    C2] RAX: dffffc0000000000 RBX: ffff88800a5399c0 RCX: ffffffff9239564a
[ 4593.744627][    C2] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff978ffa00
[ 4593.744812][    C2] RBP: ffff88800a539a20 R08: 0000000000000001 R09: fffffbfff2f1ff40
[ 4593.745001][    C2] R10: ffffffff978ffa07 R11: 205d324320202020 R12: 0000000000000000
[ 4593.745186][    C2] R13: ffff88800a539b40 R14: 0000000000000000 R15: 0000000000000008
[ 4593.745372][    C2] FS:  0000000000000000(0000) GS:ffff888036100000(0000) knlGS:0000000000000000
[ 4593.745589][    C2] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4593.745746][    C2] CR2: 00007fc42acd5258 CR3: 000000002ff38005 CR4: 0000000000770ef0
[ 4593.745936][    C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 4593.746120][    C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 4593.746311][    C2] PKRU: 55555554
[ 4593.746405][    C2] Call Trace:
[ 4593.746501][    C2]  <IRQ>
[ 4593.746565][ C2] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 4593.746677][ C2] ? exc_general_protection (arch/x86/kernel/traps.c:702 arch/x86/kernel/traps.c:644) 
[ 4593.746808][ C2] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[ 4593.746934][ C2] ? add_taint (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 kernel/panic.c:555) 
[ 4593.747030][ 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:3399) 
[ 4593.747188][ 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:3399) 
[ 4593.747341][ C2] sock_wfree (./include/linux/rcupdate.h:810 net/core/sock.c:2471) 
[ 4593.747437][ C2] ip6_rcv_core (./include/linux/skbuff.h:3202 net/ipv6/ip6_input.c:291) 
[ 4593.747563][ C2] ipv6_rcv (net/ipv6/ip6_input.c:307) 
[ 4593.747657][ C2] ? __pfx_ipv6_rcv (net/ipv6/ip6_input.c:304) 
[ 4593.747786][ C2] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5756) 
[ 4593.747910][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6047) 
[ 4593.748036][ C2] ? __pfx_ipv6_rcv (net/ipv6/ip6_input.c:304) 
[ 4593.748159][ C2] __netif_receive_skb_one_core (net/core/dev.c:5598) 
[ 4593.748315][ C2] ? __pfx___netif_receive_skb_one_core (net/core/dev.c:5598) 
[ 4593.748468][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6047) 
[ 4593.748590][ C2] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 4593.748712][ C2] ? process_backlog (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 net/core/dev.c:6047) 
[ 4593.748837][ C2] process_backlog (./include/linux/rcupdate.h:810 net/core/dev.c:6049) 
[ 4593.748963][ C2] ? __lock_release (kernel/locking/lockdep.c:5430) 
[ 4593.749086][ C2] ? rebalance_domains (./include/linux/rcupdate.h:339 ./include/linux/rcupdate.h:814 kernel/sched/fair.c:11753) 
[ 4593.749211][ C2] __napi_poll.constprop.0 (net/core/dev.c:6702) 
[ 4593.749336][ C2] net_rx_action (net/core/dev.c:6771 net/core/dev.c:6887) 
[ 4593.749461][ C2] ? __pfx_net_rx_action (net/core/dev.c:6851) 
[ 4593.749583][ C2] ? __pfx_tmigr_handle_remote (kernel/time/timer_migration.c:1026) 
[ 4593.749706][ C2] ? spin_bug (./include/linux/pid.h:232 kernel/locking/spinlock_debug.c:64 kernel/locking/spinlock_debug.c:78) 
[ 4593.749799][ C2] ? __pfx_rebalance_domains (kernel/sched/fair.c:11684) 
[ 4593.749926][ C2] __do_softirq (kernel/softirq.c:554) 
[ 4593.750050][ C2] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 4593.750144][ C2] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[ 4593.750266][    C2]  </IRQ>
[ 4593.750330][    C2]  <TASK>
[ 4593.750393][ C2] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 4593.750546][ 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) 
[ 4593.750676][ 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 e3 bc 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 e3 bc 32 00 	verw   0x32bce3(%rip)        # 0x32bd0b
  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
[ 4593.751114][    C2] RSP: 0018:ffffc9000015fdf8 EFLAGS: 00000242
[ 4593.751269][    C2] RAX: 0000000004809f01 RBX: 1ffff9200002bfc1 RCX: ffffffff94d35e95
[ 4593.751453][    C2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff924ac0e4
[ 4593.751639][    C2] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c2709c
[ 4593.751824][    C2] R10: ffff8880361384e3 R11: ffff88803612d9b0 R12: 0000000000000000
[ 4593.752010][    C2] R13: ffff888001b8c5c0 R14: dffffc0000000000 R15: 0000000000000000
[ 4593.752195][ C2] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 4593.752318][ C2] ? cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 4593.752444][ C2] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 4593.752566][ C2] cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 4593.752692][ C2] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 4593.752816][ C2] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 4593.752939][ C2] do_idle (kernel/sched/idle.c:332) 
[ 4593.753034][ C2] cpu_startup_entry (kernel/sched/idle.c:429 (discriminator 1)) 
[ 4593.753159][ C2] start_secondary (arch/x86/kernel/smpboot.c:201 arch/x86/kernel/smpboot.c:281) 
[ 4593.753283][ 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