======================================
| [ 4216.002379][    C2] ==================================================================
| [ 4216.002681][ 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) 
| [ 4216.002962][    C2] Read of size 8 at addr 0000000000000008 by task ksoftirqd/2/28
| [ 4216.003191][    C2]
[ 4216.003467][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 4216.003760][    C2] Call Trace:
[ 4216.003865][    C2]  <TASK>
[ 4216.003939][ C2] dump_stack_lvl (lib/dump_stack.c:117) 
[ 4216.004085][ C2] kasan_report (mm/kasan/report.c:603) 
[ 4216.004193][ 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) 
[ 4216.004364][ C2] kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) 
[ 4216.004499][ 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) 
[ 4216.004630][ C2] sock_wfree (./include/linux/rcupdate.h:810 net/core/sock.c:2471) 
[ 4216.004730][ C2] skb_release_head_state (net/core/skbuff.c:1162 (discriminator 3)) 
[ 4216.004863][ C2] consume_skb (net/core/skbuff.c:1174 net/core/skbuff.c:1189 net/core/skbuff.c:1405 net/core/skbuff.c:1399) 
[ 4216.004963][ C2] skb_pp_cow_data (net/core/skbuff.c:987) 
[ 4216.005097][ C2] ? __pfx_skb_pp_cow_data (net/core/skbuff.c:916) 
[ 4216.005232][ C2] ? veth_xdp_rcv_skb (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 drivers/net/veth.c:775) 
[ 4216.005366][ C2] veth_xdp_rcv_skb (drivers/net/veth.c:732 drivers/net/veth.c:783) 
[ 4216.005505][ C2] ? __pfx_veth_xdp_rcv_skb (drivers/net/veth.c:765) 
[ 4216.005636][ C2] ? dev_gro_receive (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 net/core/gro.c:537) 
[ 4216.005771][ C2] ? trace_napi_gro_receive_exit (./include/trace/events/net.h:288 (discriminator 52)) 
[ 4216.005933][ C2] ? napi_gro_receive (net/core/gro.c:617) 
[ 4216.006065][ C2] veth_xdp_rcv (drivers/net/veth.c:905) 
[ 4216.006197][ C2] ? stack_trace_save (kernel/stacktrace.c:123) 
[ 4216.006333][ C2] ? __pfx_stack_trace_save (kernel/stacktrace.c:114) 
[ 4216.006464][ C2] ? __pfx_veth_xdp_rcv (drivers/net/veth.c:875) 
[ 4216.006598][ C2] ? kasan_save_stack (mm/kasan/common.c:49) 
[ 4216.006730][ C2] ? kasan_save_stack (mm/kasan/common.c:48) 
[ 4216.006862][ C2] ? 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) 
[ 4216.006993][ C2] ? validate_chain (./include/linux/hash.h:78 kernel/locking/lockdep.c:3759 kernel/locking/lockdep.c:3782 kernel/locking/lockdep.c:3837) 
[ 4216.007125][ C2] veth_poll (drivers/net/veth.c:943) 
[ 4216.007225][ C2] ? __pfx_validate_chain (kernel/locking/lockdep.c:3825) 
[ 4216.007356][ C2] ? __pfx_veth_poll (drivers/net/veth.c:931) 
[ 4216.007491][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 4216.007624][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 4216.007755][ C2] ? __lock_release (kernel/locking/lockdep.c:5430) 
[ 4216.007886][ C2] ? finish_task_switch.isra.0 (kernel/sched/sched.h:1397 kernel/sched/core.c:5163 kernel/sched/core.c:5281) 
[ 4216.008051][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5406) 
[ 4216.008183][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 4216.008315][ C2] __napi_poll.constprop.0 (net/core/dev.c:6701) 
[ 4216.008450][ C2] net_rx_action (net/core/dev.c:6770 net/core/dev.c:6886) 
[ 4216.008585][ C2] ? __schedule (kernel/sched/core.c:6617) 
[ 4216.008717][ C2] ? __pfx_net_rx_action (net/core/dev.c:6850) 
[ 4216.008850][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 4216.008982][ C2] __do_softirq (kernel/softirq.c:554) 
[ 4216.009116][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:917) 
[ 4216.009248][ C2] run_ksoftirqd (kernel/softirq.c:411 kernel/softirq.c:925 kernel/softirq.c:916) 
[ 4216.009379][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 4216.009513][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 4216.009646][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 4216.009776][ C2] kthread (kernel/kthread.c:388) 
[ 4216.009876][ C2] ? __pfx_kthread (kernel/kthread.c:341) 
[ 4216.010009][ C2] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 4216.010142][ C2] ? __pfx_kthread (kernel/kthread.c:341) 
[ 4216.010272][ C2] ret_from_fork_asm (arch/x86/entry/entry_64.S:256) 
| [ 4216.010508][    C2] ==================================================================
| [ 4216.010719][    C2] Disabling lock debugging due to kernel taint
| [ 4216.010922][    C2] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [ 4216.011218][    C2] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
[ 4216.011643][    C2] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 4216.011943][ 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) 
[ 4216.012117][ 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
[ 4216.012603][    C2] RSP: 0018:ffffc900002076b8 EFLAGS: 00010202
[ 4216.012785][    C2] RAX: dffffc0000000000 RBX: ffff888003ba3e40 RCX: ffffffff9499564a
[ 4216.012992][    C2] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff99efda00
[ 4216.013196][    C2] RBP: ffff888003ba3ea0 R08: 0000000000000001 R09: fffffbfff33dfb40
[ 4216.013397][    C2] R10: ffffffff99efda07 R11: 205d324320202020 R12: 0000000000000000
[ 4216.013580][    C2] R13: ffff888003ba3fc0 R14: 0000000000000008 R15: 0000000000000000
[ 4216.013769][    C2] FS:  0000000000000000(0000) GS:ffff888036100000(0000) knlGS:0000000000000000
[ 4216.013981][    C2] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4216.014140][    C2] CR2: 00007fbbde4fd000 CR3: 0000000023938003 CR4: 0000000000770ef0
[ 4216.014327][    C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 4216.014509][    C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 4216.014697][    C2] PKRU: 55555554
[ 4216.014793][    C2] Call Trace:
[ 4216.014885][    C2]  <TASK>
[ 4216.014951][ C2] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[ 4216.015046][ C2] ? exc_general_protection (arch/x86/kernel/traps.c:702 arch/x86/kernel/traps.c:644) 
[ 4216.015178][ C2] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[ 4216.015305][ C2] ? add_taint (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 kernel/panic.c:555) 
[ 4216.015400][ 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) 
[ 4216.015557][ 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) 
[ 4216.015713][ C2] sock_wfree (./include/linux/rcupdate.h:810 net/core/sock.c:2471) 
[ 4216.015808][ C2] skb_release_head_state (net/core/skbuff.c:1162 (discriminator 3)) 
[ 4216.015930][ C2] consume_skb (net/core/skbuff.c:1174 net/core/skbuff.c:1189 net/core/skbuff.c:1405 net/core/skbuff.c:1399) 
[ 4216.016024][ C2] skb_pp_cow_data (net/core/skbuff.c:987) 
[ 4216.016152][ C2] ? __pfx_skb_pp_cow_data (net/core/skbuff.c:916) 
[ 4216.016275][ C2] ? veth_xdp_rcv_skb (./include/linux/rcupdate.h:329 ./include/linux/rcupdate.h:781 drivers/net/veth.c:775) 
[ 4216.016399][ C2] veth_xdp_rcv_skb (drivers/net/veth.c:732 drivers/net/veth.c:783) 
[ 4216.016525][ C2] ? __pfx_veth_xdp_rcv_skb (drivers/net/veth.c:765) 
[ 4216.016647][ C2] ? dev_gro_receive (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 net/core/gro.c:537) 
[ 4216.016772][ C2] ? trace_napi_gro_receive_exit (./include/trace/events/net.h:288 (discriminator 52)) 
[ 4216.016927][ C2] ? napi_gro_receive (net/core/gro.c:617) 
[ 4216.017050][ C2] veth_xdp_rcv (drivers/net/veth.c:905) 
[ 4216.017179][ C2] ? stack_trace_save (kernel/stacktrace.c:123) 
[ 4216.017303][ C2] ? __pfx_stack_trace_save (kernel/stacktrace.c:114) 
[ 4216.017424][ C2] ? __pfx_veth_xdp_rcv (drivers/net/veth.c:875) 
[ 4216.017547][ C2] ? kasan_save_stack (mm/kasan/common.c:49) 
[ 4216.017676][ C2] ? kasan_save_stack (mm/kasan/common.c:48) 
[ 4216.017800][ C2] ? 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) 
[ 4216.017922][ C2] ? validate_chain (./include/linux/hash.h:78 kernel/locking/lockdep.c:3759 kernel/locking/lockdep.c:3782 kernel/locking/lockdep.c:3837) 
[ 4216.018046][ C2] veth_poll (drivers/net/veth.c:943) 
[ 4216.018141][ C2] ? __pfx_validate_chain (kernel/locking/lockdep.c:3825) 
[ 4216.018265][ C2] ? __pfx_veth_poll (drivers/net/veth.c:931) 
[ 4216.018388][ C2] ? __lock_acquire (kernel/locking/lockdep.c:5137) 
[ 4216.018511][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 4216.018632][ C2] ? __lock_release (kernel/locking/lockdep.c:5430) 
[ 4216.018759][ C2] ? finish_task_switch.isra.0 (kernel/sched/sched.h:1397 kernel/sched/core.c:5163 kernel/sched/core.c:5281) 
[ 4216.018913][ C2] ? __pfx___lock_release (kernel/locking/lockdep.c:5406) 
[ 4216.019036][ C2] ? find_held_lock (kernel/locking/lockdep.c:5244) 
[ 4216.019161][ C2] __napi_poll.constprop.0 (net/core/dev.c:6701) 
[ 4216.019284][ C2] net_rx_action (net/core/dev.c:6770 net/core/dev.c:6886) 
[ 4216.019410][ C2] ? __schedule (kernel/sched/core.c:6617) 
[ 4216.019534][ C2] ? __pfx_net_rx_action (net/core/dev.c:6850) 
[ 4216.019658][ C2] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5719) 
[ 4216.019785][ C2] __do_softirq (kernel/softirq.c:554) 
[ 4216.019911][ C2] ? __pfx_run_ksoftirqd (kernel/softirq.c:917) 
[ 4216.020035][ C2] run_ksoftirqd (kernel/softirq.c:411 kernel/softirq.c:925 kernel/softirq.c:916) 
[ 4216.020157][ C2] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 4216.020279][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 4216.020401][ C2] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 4216.020522][ C2] kthread (kernel/kthread.c:388) 
[ 4216.020614][ C2] ? __pfx_kthread (kernel/kthread.c:341) 
[ 4216.020739][ C2] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 4216.020862][ C2] ? __pfx_kthread (kernel/kthread.c:341) 


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