======================================
| [ 3442.038169][    C0] ==================================================================
| [ 3442.038440][ C0] BUG: KASAN: slab-use-after-free in vrf_xmit (drivers/net/vrf.c:567)
| [ 3442.038635][    C0] Read of size 4 at addr ffff88800213faf0 by task ping/28868
| [ 3442.038858][    C0]
[ 3442.039162][    C0] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 3442.039366][    C0] Call Trace:
[ 3442.039483][    C0]  <IRQ>
[ 3442.039562][ C0] dump_stack_lvl (lib/dump_stack.c:123)
[ 3442.039718][ C0] print_address_description.constprop.0 (mm/kasan/report.c:379)
[ 3442.039912][ C0] ? vrf_xmit (drivers/net/vrf.c:567)
[ 3442.040030][ C0] print_report (mm/kasan/report.c:490)
[ 3442.040182][ C0] ? kasan_addr_to_slab (./include/linux/mm.h:1294 mm/kasan/../slab.h:211 mm/kasan/common.c:38)
[ 3442.040334][ C0] kasan_report (mm/kasan/report.c:604)
[ 3442.040456][ C0] ? vrf_xmit (drivers/net/vrf.c:567)
[ 3442.040575][ C0] vrf_xmit (drivers/net/vrf.c:567)
[ 3442.040692][ C0] dev_hard_start_xmit (./include/linux/netdevice.h:5042 ./include/linux/netdevice.h:5051 net/core/dev.c:3590 net/core/dev.c:3606)
[ 3442.040847][ C0] __dev_queue_xmit (net/core/dev.h:291 net/core/dev.c:4435)
[ 3442.041001][ C0] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 3442.041156][ C0] ? ip_finish_output2 (./include/net/neighbour.h:537 net/ipv4/ip_output.c:236)
[ 3442.041311][ C0] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 3442.041469][ C0] ? 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)
[ 3442.041623][ C0] ? __pfx___dev_queue_xmit (net/core/dev.c:4343)
[ 3442.041776][ C0] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 3442.041931][ C0] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4339 kernel/locking/lockdep.c:4406)
[ 3442.042120][ C0] ? neigh_hh_output (./include/linux/seqlock.h:74 ./include/linux/seqlock.h:813 ./include/net/neighbour.h:493)
[ 3442.042275][ C0] ip_finish_output2 (./include/net/neighbour.h:537 net/ipv4/ip_output.c:236)
[ 3442.042431][ C0] ? __pfx_ip_finish_output2 (net/ipv4/ip_output.c:200)
[ 3442.042590][ C0] ? __ip_finish_output (./include/linux/skbuff.h:1670 ./include/linux/skbuff.h:5049 net/ipv4/ip_output.c:308 net/ipv4/ip_output.c:296)
[ 3442.042745][ C0] ip_output (./include/linux/netfilter.h:303 net/ipv4/ip_output.c:434)
[ 3442.042860][ C0] ? __pfx_ip_output (net/ipv4/ip_output.c:428)
[ 3442.043014][ C0] ? ip_route_input_noref (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/ipv4/route.c:2520)
[ 3442.043169][ C0] ? ip_forward_finish (./include/linux/skbuff.h:1144 ./include/net/dst.h:450 net/ipv4/ip_forward.c:80)
[ 3442.043321][ C0] NF_HOOK.constprop.0 (./include/linux/netfilter.h:314)
[ 3442.043472][ C0] ? __pfx_NF_HOOK.constprop.0 (./include/linux/netfilter.h:308)
[ 3442.043624][ C0] ? ip_dst_mtu_maybe_forward.constprop.0 (./include/net/net_namespace.h:387 ./include/linux/netdevice.h:2635 ./include/net/ip.h:474)
[ 3442.043816][ C0] ? ip_forward (net/ipv4/ip_forward.c:45 net/ipv4/ip_forward.c:135)
[ 3442.043969][ C0] ip_rcv (./include/net/dst.h:460 ./include/net/dst.h:458 net/ipv4/ip_input.c:447 ./include/linux/netfilter.h:314 ./include/linux/netfilter.h:308 net/ipv4/ip_input.c:567)
[ 3442.044085][ C0] ? __pfx_ip_rcv (net/ipv4/ip_input.c:560)
[ 3442.044241][ C0] ? process_backlog (./include/linux/local_lock_internal.h:38 net/core/dev.c:6115)
[ 3442.044393][ C0] ? lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 3442.044547][ C0] ? process_backlog (./include/linux/local_lock_internal.h:38 net/core/dev.c:6115)
[ 3442.044698][ C0] ? __pfx_ip_rcv (net/ipv4/ip_input.c:560)
[ 3442.044855][ C0] ? process_backlog (./include/linux/local_lock_internal.h:38 net/core/dev.c:6115)
[ 3442.045006][ C0] __netif_receive_skb_one_core (net/core/dev.c:5672 (discriminator 4))
[ 3442.045194][ C0] ? __pfx___netif_receive_skb_one_core (net/core/dev.c:5665)
[ 3442.045384][ C0] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 3442.045536][ C0] ? process_backlog (./include/linux/local_lock_internal.h:38 net/core/dev.c:6115)
[ 3442.045689][ C0] process_backlog (./include/linux/rcupdate.h:878 net/core/dev.c:6118)
[ 3442.045842][ C0] __napi_poll.constprop.0 (net/core/dev.c:6883)
[ 3442.045999][ C0] net_rx_action (net/core/dev.c:6952 net/core/dev.c:7074)
[ 3442.046155][ C0] ? __pfx_net_rx_action (net/core/dev.c:7036)
[ 3442.046308][ C0] ? _nohz_idle_balance.isra.0 (kernel/sched/sched.h:1542 kernel/sched/sched.h:1821 kernel/sched/fair.c:12593)
[ 3442.046496][ C0] ? 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)
[ 3442.046646][ C0] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 3442.046763][ C0] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 3442.046916][ C0] handle_softirqs (kernel/softirq.c:554)
[ 3442.047068][ C0] ? __dev_queue_xmit (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:917 net/core/dev.c:4461)
[ 3442.047222][ C0] do_softirq (kernel/softirq.c:455 kernel/softirq.c:442)
[ 3442.047339][    C0]  </IRQ>
[ 3442.047420][    C0]  <TASK>
[ 3442.047496][ C0] __local_bh_enable_ip (kernel/softirq.c:382)
[ 3442.047647][ C0] ? __dev_queue_xmit (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:917 net/core/dev.c:4461)
[ 3442.047800][ C0] __dev_queue_xmit (net/core/dev.c:4462)
[ 3442.047963][ C0] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 3442.048115][ C0] ? ip_finish_output2 (./include/net/neighbour.h:537 net/ipv4/ip_output.c:236)
[ 3442.048270][ C0] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 3442.048421][ C0] ? 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)
[ 3442.048573][ C0] ? __pfx___dev_queue_xmit (net/core/dev.c:4343)
[ 3442.048726][ C0] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 3442.048883][ C0] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 3442.049073][ C0] ? neigh_hh_output (./include/linux/seqlock.h:74 ./include/linux/seqlock.h:813 ./include/net/neighbour.h:493)
[ 3442.049226][ C0] ? do_csum (lib/checksum.c:56)
[ 3442.049348][ C0] ip_finish_output2 (./include/net/neighbour.h:537 net/ipv4/ip_output.c:236)
[ 3442.049502][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5226)
[ 3442.049673][ C0] ? __pfx_raw_getfrag (net/ipv4/raw.c:453)
[ 3442.049828][ C0] ? __pfx_ip_finish_output2 (net/ipv4/ip_output.c:200)
[ 3442.049980][ C0] ? __ip_finish_output (./include/linux/skbuff.h:1670 ./include/linux/skbuff.h:5049 net/ipv4/ip_output.c:308 net/ipv4/ip_output.c:296)
[ 3442.050133][ C0] ip_output (./include/linux/netfilter.h:303 net/ipv4/ip_output.c:434)
[ 3442.050248][ C0] ? __ip_local_out (net/ipv4/ip_output.c:97 net/ipv4/ip_output.c:108)
[ 3442.050399][ C0] ? __pfx_ip_output (net/ipv4/ip_output.c:428)
[ 3442.050555][ C0] ? __ip_make_skb (net/ipv4/ip_output.c:1386 net/ipv4/ip_output.c:1496)
[ 3442.050708][ C0] ? __pfx_raw_getfrag (net/ipv4/raw.c:453)
[ 3442.050860][ C0] ? ip_append_data (net/ipv4/ip_output.c:1375 net/ipv4/ip_output.c:1354)
[ 3442.051017][ C0] ip_push_pending_frames (./include/net/dst.h:450 net/ipv4/ip_output.c:130 net/ipv4/ip_output.c:1505 net/ipv4/ip_output.c:1525)
[ 3442.051170][ C0] raw_sendmsg (net/ipv4/raw.c:658)
[ 3442.051325][ C0] ? __pfx_raw_sendmsg (net/ipv4/raw.c:483)
[ 3442.051480][ C0] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 3442.051633][ C0] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 3442.051789][ C0] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 47))
[ 3442.051941][ C0] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 3442.052093][ C0] ? __might_fault (mm/memory.c:6751 mm/memory.c:6744)
[ 3442.052250][ C0] ? __might_fault (mm/memory.c:6751 mm/memory.c:6744)
[ 3442.052403][ C0] __sys_sendto (net/socket.c:711 net/socket.c:726 net/socket.c:2197)
[ 3442.052556][ C0] ? __pfx___sys_sendto (net/socket.c:2164)
[ 3442.052709][ C0] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 3442.052866][ C0] ? rseq_update_cpu_node_id (kernel/rseq.c:109 (discriminator 10))
[ 3442.053021][ C0] ? __rseq_handle_notify_resume (kernel/rseq.c:333)
[ 3442.053209][ C0] ? do_user_addr_fault (./include/linux/mmap_lock.h:172 arch/x86/mm/fault.c:1417)
[ 3442.053362][ C0] ? __pfx___rseq_handle_notify_resume (kernel/rseq.c:316)
[ 3442.053555][ C0] __x64_sys_sendto (net/socket.c:2200)
[ 3442.053708][ C0] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 3442.053895][ C0] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 3442.054051][ C0] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 3442.054242][    C0] RIP: 0033:0x7f375245b85a
[ 3442.054400][ C0] Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89
All code
========
   0:	d8 64 89 02          	fsubs  0x2(%rcx,%rcx,4)
   4:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   b:	eb b8                	jmp    0xffffffffffffffc5
   d:	0f 1f 00             	nopl   (%rax)
  10:	f3 0f 1e fa          	endbr64
  14:	41 89 ca             	mov    %ecx,%r10d
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 15                	jne    0x38
  23:	b8 2c 00 00 00       	mov    $0x2c,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 7e                	ja     0xb0
  32:	c3                   	ret
  33:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  38:	41 54                	push   %r12
  3a:	48 83 ec 30          	sub    $0x30,%rsp
  3e:	44                   	rex.R
  3f:	89                   	.byte 0x89

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 7e                	ja     0x86
   8:	c3                   	ret
   9:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   e:	41 54                	push   %r12
  10:	48 83 ec 30          	sub    $0x30,%rsp
  14:	44                   	rex.R
  15:	89                   	.byte 0x89
[ 3442.054935][    C0] RSP: 002b:00007ffeb4f22b38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[ 3442.055170][    C0] RAX: ffffffffffffffda RBX: 00000000000005aa RCX: 00007f375245b85a
[ 3442.055398][    C0] RDX: 00000000000005b2 RSI: 000000003c957340 RDI: 0000000000000005
[ 3442.055627][    C0] RBP: 00007ffeb4f22b90 R08: 00000000004185e0 R09: 0000000000000010
[ 3442.055857][    C0] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000005c6


Finger prints:
print_report:kasan_report:vrf_xmit:dev_hard_start_xmit:__dev_queue_xmit