======================================
| [ 2669.275171][    C3] ==================================================================
| [ 2669.275431][ C3] 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) 
| [ 2669.275660][    C3] Read of size 8 at addr 0000000000000008 by task swapper/3/0
| [ 2669.275873][    C3]
[ 2669.276187][    C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 2669.276523][    C3] Call Trace:
[ 2669.276638][    C3]  <IRQ>
[ 2669.276715][ C3] dump_stack_lvl (lib/dump_stack.c:117) 
[ 2669.276864][ C3] kasan_report (mm/kasan/report.c:603) 
[ 2669.276977][ C3] ? 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) 
[ 2669.277164][ C3] kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) 
[ 2669.277312][ C3] 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) 
[ 2669.277461][ C3] sock_wfree (./include/linux/rcupdate.h:810 net/core/sock.c:2471) 
[ 2669.277576][ C3] skb_release_head_state (net/core/skbuff.c:1162 (discriminator 3)) 
[ 2669.277725][ C3] consume_skb (net/core/skbuff.c:1174 net/core/skbuff.c:1189 net/core/skbuff.c:1405 net/core/skbuff.c:1399) 
[ 2669.277840][ C3] dummy_xmit (drivers/net/dummy.c:66) 
[ 2669.277952][ C3] ? trace_net_dev_start_xmit (./include/trace/events/net.h:14 (discriminator 52)) 
[ 2669.278098][ C3] dev_hard_start_xmit (./include/linux/netdevice.h:4875 ./include/linux/netdevice.h:4889 net/core/dev.c:3563 net/core/dev.c:3579) 
[ 2669.278249][ C3] sch_direct_xmit (net/sched/sch_generic.c:343) 
[ 2669.278398][ C3] ? __pfx_sch_direct_xmit (net/sched/sch_generic.c:318) 
[ 2669.278547][ C3] __qdisc_run (net/sched/sch_generic.c:416) 
[ 2669.278694][ C3] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 2669.278842][ C3] ? __pfx___qdisc_run (net/sched/sch_generic.c:412) 
[ 2669.278990][ C3] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:115 ./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) 
[ 2669.279139][ C3] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 2669.279286][ C3] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 2669.279438][ C3] ? net_tx_action (./include/linux/spinlock.h:352 net/core/dev.c:5250) 
[ 2669.279585][ C3] net_tx_action (./include/net/sch_generic.h:217 ./include/net/pkt_sched.h:128 ./include/net/pkt_sched.h:124 net/core/dev.c:5266) 
[ 2669.279733][ C3] __do_softirq (kernel/softirq.c:554) 
[ 2669.279884][ C3] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 2669.279994][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[ 2669.280142][    C3]  </IRQ>
[ 2669.280220][    C3]  <TASK>
[ 2669.280292][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 2669.280475][ C3] RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:72 arch/x86/kernel/process.c:743) 
[ 2669.280637][ C3] 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 cc 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 cc 32 00 	verw   0x32cce3(%rip)        # 0x32cd0b
  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
[ 2669.281173][    C3] RSP: 0018:ffffc9000016fdf8 EFLAGS: 00000242
[ 2669.281374][    C3] RAX: 0000000003e16ae9 RBX: 1ffff9200002dfc1 RCX: ffffffffb5534e95
[ 2669.281603][    C3] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffb2cac0e4
[ 2669.281828][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c3709c
[ 2669.282056][    C3] R10: ffff8880361b84e3 R11: ffff8880361bde40 R12: 0000000000000000
[ 2669.282283][    C3] R13: ffff888001b98040 R14: dffffc0000000000 R15: 0000000000000000
[ 2669.282506][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 2669.282661][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 2669.282812][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 2669.282965][ C3] cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 2669.283114][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 2669.283260][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 2669.283412][ C3] do_idle (kernel/sched/idle.c:332) 
[ 2669.283527][ C3] cpu_startup_entry (kernel/sched/idle.c:429 (discriminator 1)) 
[ 2669.283690][ C3] start_secondary (arch/x86/kernel/smpboot.c:201 arch/x86/kernel/smpboot.c:281) 
[ 2669.283839][ C3] ? __pfx_start_secondary (arch/x86/kernel/smpboot.c:231) 
[ 2669.283989][ C3] common_startup_64 (arch/x86/kernel/head_64.S:421) 
| [ 2669.284259][    C3] ==================================================================
| [ 2669.284492][    C3] Disabling lock debugging due to kernel taint
| [ 2669.284711][    C3] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [ 2669.285048][    C3] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
[ 2669.285520][    C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 2669.285853][ C3] 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) 
[ 2669.286049][ C3] 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
[ 2669.286574][    C3] RSP: 0018:ffffc90000288c30 EFLAGS: 00010202
[ 2669.286757][    C3] RAX: dffffc0000000000 RBX: ffff8880055e0040 RCX: ffffffffb2b9564a
[ 2669.286975][    C3] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffffb80fda00
[ 2669.287198][    C3] RBP: ffff8880055e00a0 R08: 0000000000000001 R09: fffffbfff701fb40
[ 2669.287419][    C3] R10: ffffffffb80fda07 R11: 205d334320202020 R12: 0000000000000000
[ 2669.287646][    C3] R13: ffff8880055e01c0 R14: 0000000000000008 R15: 0000000000000000
[ 2669.287878][    C3] FS:  0000000000000000(0000) GS:ffff888036180000(0000) knlGS:0000000000000000
[ 2669.288134][    C3] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2669.288328][    C3] CR2: 0000557e47b9fdec CR3: 0000000006a68002 CR4: 0000000000770ef0
[ 2669.288551][    C3] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2669.288779][    C3] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2669.289001][    C3] PKRU: 55555554
[ 2669.289108][    C3] Call Trace:
[ 2669.289221][    C3]  <IRQ>
[ 2669.289294][ C3] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 2669.289406][ C3] ? exc_general_protection (arch/x86/kernel/traps.c:702 arch/x86/kernel/traps.c:644) 
[ 2669.289556][ C3] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[ 2669.289712][ C3] ? add_taint (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 kernel/panic.c:555) 
[ 2669.289828][ C3] ? 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) 
[ 2669.290009][ C3] sock_wfree (./include/linux/rcupdate.h:810 net/core/sock.c:2471) 
[ 2669.290122][ C3] skb_release_head_state (net/core/skbuff.c:1162 (discriminator 3)) 
[ 2669.290276][ C3] consume_skb (net/core/skbuff.c:1174 net/core/skbuff.c:1189 net/core/skbuff.c:1405 net/core/skbuff.c:1399) 
[ 2669.290385][ C3] dummy_xmit (drivers/net/dummy.c:66) 
[ 2669.290500][ C3] ? trace_net_dev_start_xmit (./include/trace/events/net.h:14 (discriminator 52)) 
[ 2669.290654][ C3] dev_hard_start_xmit (./include/linux/netdevice.h:4875 ./include/linux/netdevice.h:4889 net/core/dev.c:3563 net/core/dev.c:3579) 
[ 2669.290813][ C3] sch_direct_xmit (net/sched/sch_generic.c:343) 
[ 2669.290961][ C3] ? __pfx_sch_direct_xmit (net/sched/sch_generic.c:318) 
[ 2669.291112][ C3] __qdisc_run (net/sched/sch_generic.c:416) 
[ 2669.291262][ C3] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 2669.291407][ C3] ? __pfx___qdisc_run (net/sched/sch_generic.c:412) 
[ 2669.291547][ C3] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:115 ./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) 
[ 2669.291689][ C3] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114) 
[ 2669.291828][ C3] ? lock_acquire (kernel/locking/lockdep.c:5727) 
[ 2669.291974][ C3] ? net_tx_action (./include/linux/spinlock.h:352 net/core/dev.c:5250) 
[ 2669.292207][ C3] net_tx_action (./include/net/sch_generic.h:217 ./include/net/pkt_sched.h:128 ./include/net/pkt_sched.h:124 net/core/dev.c:5266) 
[ 2669.292350][ C3] __do_softirq (kernel/softirq.c:554) 
[ 2669.292486][ C3] irq_exit_rcu (kernel/softirq.c:428 kernel/softirq.c:633 kernel/softirq.c:645) 
[ 2669.292596][ C3] sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1043 arch/x86/kernel/apic/apic.c:1043) 
[ 2669.292749][    C3]  </IRQ>
[ 2669.292822][    C3]  <TASK>
[ 2669.292896][ C3] asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:702) 
[ 2669.293161][ C3] RIP: 0010:default_idle (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:72 arch/x86/kernel/process.c:743) 
[ 2669.293309][ C3] 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 cc 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 cc 32 00 	verw   0x32cce3(%rip)        # 0x32cd0b
  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
[ 2669.293821][    C3] RSP: 0018:ffffc9000016fdf8 EFLAGS: 00000242
[ 2669.293999][    C3] RAX: 0000000003e16ae9 RBX: 1ffff9200002dfc1 RCX: ffffffffb5534e95
[ 2669.294212][    C3] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffb2cac0e4
[ 2669.294518][    C3] RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed1006c3709c
[ 2669.294743][    C3] R10: ffff8880361b84e3 R11: ffff8880361bde40 R12: 0000000000000000
[ 2669.294958][    C3] R13: ffff888001b98040 R14: dffffc0000000000 R15: 0000000000000000
[ 2669.295173][ C3] ? ct_kernel_exit.constprop.0 (kernel/context_tracking.c:147) 
[ 2669.295315][ C3] ? cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 2669.295458][ C3] default_idle_call (./include/linux/cpuidle.h:143 kernel/sched/idle.c:118) 
[ 2669.295602][ C3] cpuidle_idle_call (kernel/sched/idle.c:192) 
[ 2669.295818][ C3] ? __pfx_cpuidle_idle_call (kernel/sched/idle.c:168) 
[ 2669.295969][ C3] ? tsc_verify_tsc_adjust (arch/x86/kernel/tsc_sync.c:59) 
[ 2669.296116][ C3] do_idle (kernel/sched/idle.c:332) 
[ 2669.296223][ C3] cpu_startup_entry (kernel/sched/idle.c:429 (discriminator 1)) 
[ 2669.296379][ C3] start_secondary (arch/x86/kernel/smpboot.c:201 arch/x86/kernel/smpboot.c:281) 
[ 2669.296598][ C3] ? __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:skb_release_head_state:consume_skb