======================================
| [ 2631.044690][T24688] ==================================================================
| [2631.044955][T24688] BUG: KASAN: null-ptr-deref in nexthop_create_group (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/linux/refcount.h:136 ./include/linux/refcount.h:142 ./include/linux/refcount.h:218 ./include/linux/refcount.h:236 ./include/net/nexthop.h:264 net/ipv4/nexthop.c:2721) 
| [ 2631.045186][T24688] Read of size 4 at addr 0000000000000068 by task ip/24688
| [ 2631.045405][T24688]
[ 2631.045492][T24688] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 2631.045494][T24688] Call Trace:
[ 2631.045496][T24688]  <TASK>
[2631.045498][T24688] dump_stack_lvl (lib/dump_stack.c:123) 
[2631.045505][T24688] kasan_report (mm/kasan/report.c:636) 
[2631.045512][T24688] ? nexthop_create_group (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/linux/refcount.h:136 ./include/linux/refcount.h:142 ./include/linux/refcount.h:218 ./include/linux/refcount.h:236 ./include/net/nexthop.h:264 net/ipv4/nexthop.c:2721) 
[2631.045518][T24688] kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) 
[2631.045522][T24688] nexthop_create_group (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/linux/refcount.h:136 ./include/linux/refcount.h:142 ./include/linux/refcount.h:218 ./include/linux/refcount.h:236 ./include/net/nexthop.h:264 net/ipv4/nexthop.c:2721) 
[2631.045529][T24688] ? __pfx_nexthop_create_group (net/ipv4/nexthop.c:2686) 
[2631.045533][T24688] ? __nla_validate_parse (lib/nlattr.c:638) 
[2631.045540][T24688] rtm_new_nexthop (net/ipv4/nexthop.c:2937 net/ipv4/nexthop.c:3254) 
[2631.045543][T24688] ? 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:230) 
[2631.045548][T24688] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2631.045553][T24688] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2631.045565][T24688] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6952) 
[2631.045571][T24688] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2631.045575][T24688] rtnetlink_rcv_msg (net/core/rtnetlink.c:6954) 
[2631.045579][T24688] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2631.045583][T24688] ? 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:230) 
[2631.045585][T24688] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2631.045590][T24688] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[2631.045594][T24688] netlink_rcv_skb (net/netlink/af_netlink.c:2534) 
[2631.045599][T24688] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2631.045603][T24688] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2511) 
[2631.045610][T24688] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340) 
[2631.045614][T24688] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/net/netns/generic.h:48 net/netlink/af_netlink.c:333) 
[2631.045618][T24688] netlink_unicast (net/netlink/af_netlink.c:1313 net/netlink/af_netlink.c:1339) 
[2631.045622][T24688] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1324) 
[2631.045625][T24688] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2631.045630][T24688] netlink_sendmsg (net/netlink/af_netlink.c:1883) 
[2631.045634][T24688] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1802) 
[2631.045641][T24688] ____sys_sendmsg (net/socket.c:709 net/socket.c:724 net/socket.c:2563) 
[2631.045646][T24688] ? __pfx_____sys_sendmsg (net/socket.c:2509) 
[2631.045649][T24688] ? __pfx_copy_msghdr_from_user (net/socket.c:2489) 
[2631.045658][T24688] ___sys_sendmsg (net/socket.c:2619) 
[2631.045661][T24688] ? 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:230) 
[2631.045664][T24688] ? __pfx____sys_sendmsg (net/socket.c:2606) 
[2631.045669][T24688] ? usage_skip (kernel/locking/lockdep.c:2316 kernel/locking/lockdep.c:2284) 
[2631.045674][T24688] ? do_user_addr_fault (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 ./include/linux/mm.h:740 arch/x86/mm/fault.c:1339) 
[2631.045679][T24688] ? do_user_addr_fault (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 ./include/linux/mm.h:740 arch/x86/mm/fault.c:1339) 
[2631.045684][T24688] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2631.045688][T24688] ? __lock_release (kernel/locking/lockdep.c:5527) 
[2631.045691][T24688] __sys_sendmsg (net/socket.c:2649) 
[2631.045695][T24688] ? __pfx___sys_sendmsg (net/socket.c:2634) 
[2631.045701][T24688] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[2631.045706][T24688] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[2631.045711][T24688] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[ 2631.045715][T24688] RIP: 0033:0x7f99266c29a7
[ 2631.045719][T24688] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
All code
========
   0:	0a 00                	or     (%rax),%al
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b9                	jmp    0xffffffffffffffc9
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 2e 00 00 00       	mov    $0x2e,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  3b:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  11:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)
[ 2631.045721][T24688] RSP: 002b:00007ffd7ebe8388 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 2631.045726][T24688] RAX: ffffffffffffffda RBX: 00007ffd7ebe8ee0 RCX: 00007f99266c29a7
[ 2631.045728][T24688] RDX: 0000000000000000 RSI: 00007ffd7ebe83f0 RDI: 0000000000000005
[ 2631.045730][T24688] RBP: 00007ffd7ebe88b0 R08: 00000000336b6910 R09: 0000000000000000
[ 2631.045731][T24688] R10: 00007f992657b708 R11: 0000000000000246 R12: 00000000336b6918
[ 2631.045733][T24688] R13: 0000000067da6b5d R14: 0000000000498600 R15: 00000000336b6910
| [ 2631.054945][T24688] Disabling lock debugging due to kernel taint
| [ 2631.055155][T24688] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [ 2631.055525][T24688] KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
| [ 2631.056001][T24688] Tainted: [B]=BAD_PAGE
[ 2631.056116][T24688] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[2631.056305][T24688] RIP: 0010:nexthop_create_group (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/linux/refcount.h:136 ./include/linux/refcount.h:142 ./include/linux/refcount.h:218 ./include/linux/refcount.h:236 ./include/net/nexthop.h:264 net/ipv4/nexthop.c:2721) 
[ 2631.056501][T24688] Code: 5c 09 00 00 45 3b 7e 60 72 c0 76 06 49 83 c6 08 eb bc 4d 8d 7e 68 be 04 00 00 00 4c 89 ff e8 c4 a2 27 fe 4c 89 f8 48 c1 e8 03 <42> 0f b6 14 20 4c 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85
All code
========
   0:	5c                   	pop    %rsp
   1:	09 00                	or     %eax,(%rax)
   3:	00 45 3b             	add    %al,0x3b(%rbp)
   6:	7e 60                	jle    0x68
   8:	72 c0                	jb     0xffffffffffffffca
   a:	76 06                	jbe    0x12
   c:	49 83 c6 08          	add    $0x8,%r14
  10:	eb bc                	jmp    0xffffffffffffffce
  12:	4d 8d 7e 68          	lea    0x68(%r14),%r15
  16:	be 04 00 00 00       	mov    $0x4,%esi
  1b:	4c 89 ff             	mov    %r15,%rdi
  1e:	e8 c4 a2 27 fe       	call   0xfffffffffe27a2e7
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
  2a:*	42 0f b6 14 20       	movzbl (%rax,%r12,1),%edx		<-- trapping instruction
  2f:	4c 89 f8             	mov    %r15,%rax
  32:	83 e0 07             	and    $0x7,%eax
  35:	83 c0 03             	add    $0x3,%eax
  38:	38 d0                	cmp    %dl,%al
  3a:	7c 08                	jl     0x44
  3c:	84 d2                	test   %dl,%dl
  3e:	0f                   	.byte 0xf
  3f:	85                   	.byte 0x85

Code starting with the faulting instruction
===========================================
   0:	42 0f b6 14 20       	movzbl (%rax,%r12,1),%edx
   5:	4c 89 f8             	mov    %r15,%rax
   8:	83 e0 07             	and    $0x7,%eax
   b:	83 c0 03             	add    $0x3,%eax
   e:	38 d0                	cmp    %dl,%al
  10:	7c 08                	jl     0x1a
  12:	84 d2                	test   %dl,%dl
  14:	0f                   	.byte 0xf
  15:	85                   	.byte 0x85
[ 2631.057018][T24688] RSP: 0018:ffffc90009ba73c8 EFLAGS: 00010202
[ 2631.057205][T24688] RAX: 000000000000000d RBX: ffff88800c6e0e68 RCX: ffffffff9605e00a
[ 2631.057438][T24688] RDX: fffffbfff3785891 RSI: 0000000000000008 RDI: ffffffff9bc2c480
[ 2631.057660][T24688] RBP: 0000000000000000 R08: 0000000000000001 R09: fffffbfff3785890
[ 2631.057879][T24688] R10: ffffffff9bc2c487 R11: 205d383836343254 R12: dffffc0000000000
[ 2631.058099][T24688] R13: ffff88801464e640 R14: 0000000000000000 R15: 0000000000000068
[ 2631.058321][T24688] FS:  00007f99264b6800(0000) GS:ffff888065b80000(0000) knlGS:0000000000000000
[ 2631.058580][T24688] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2631.058763][T24688] CR2: 00007f9926712429 CR3: 000000000b29e003 CR4: 0000000000772ef0
[ 2631.058982][T24688] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2631.059200][T24688] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2631.059420][T24688] PKRU: 55555554
[ 2631.059531][T24688] Call Trace:
[ 2631.059642][T24688]  <TASK>
[2631.059718][T24688] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[2631.059831][T24688] ? exc_general_protection (arch/x86/kernel/traps.c:751 arch/x86/kernel/traps.c:693) 
[2631.059981][T24688] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[2631.060130][T24688] ? add_taint (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 kernel/panic.c:605) 
[2631.060246][T24688] ? nexthop_create_group (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/linux/refcount.h:136 ./include/linux/refcount.h:142 ./include/linux/refcount.h:218 ./include/linux/refcount.h:236 ./include/net/nexthop.h:264 net/ipv4/nexthop.c:2721) 
[2631.060394][T24688] ? nexthop_create_group (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/linux/refcount.h:136 ./include/linux/refcount.h:142 ./include/linux/refcount.h:218 ./include/linux/refcount.h:236 ./include/net/nexthop.h:264 net/ipv4/nexthop.c:2721) 
[2631.060542][T24688] ? __pfx_nexthop_create_group (net/ipv4/nexthop.c:2686) 
[2631.060688][T24688] ? __nla_validate_parse (lib/nlattr.c:638) 
[2631.060839][T24688] rtm_new_nexthop (net/ipv4/nexthop.c:2937 net/ipv4/nexthop.c:3254) 
[2631.060989][T24688] ? 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:230) 
[2631.061135][T24688] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2631.061253][T24688] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2631.061409][T24688] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6952) 
[2631.061557][T24688] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2631.061705][T24688] rtnetlink_rcv_msg (net/core/rtnetlink.c:6954) 
[2631.061851][T24688] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2631.061997][T24688] ? 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:230) 
[2631.062143][T24688] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2631.062257][T24688] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[2631.062404][T24688] netlink_rcv_skb (net/netlink/af_netlink.c:2534) 
[2631.062561][T24688] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2631.062709][T24688] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2511) 
[2631.062858][T24688] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340) 
[2631.063004][T24688] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/net/netns/generic.h:48 net/netlink/af_netlink.c:333) 
[2631.063153][T24688] netlink_unicast (net/netlink/af_netlink.c:1313 net/netlink/af_netlink.c:1339) 
[2631.063306][T24688] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1324) 
[2631.063452][T24688] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2631.063599][T24688] netlink_sendmsg (net/netlink/af_netlink.c:1883) 
[2631.063749][T24688] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1802) 
[2631.063897][T24688] ____sys_sendmsg (net/socket.c:709 net/socket.c:724 net/socket.c:2563) 
[2631.064041][T24688] ? __pfx_____sys_sendmsg (net/socket.c:2509) 
[2631.064187][T24688] ? __pfx_copy_msghdr_from_user (net/socket.c:2489) 
[2631.064383][T24688] ___sys_sendmsg (net/socket.c:2619) 
[2631.064528][T24688] ? 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:230) 
[2631.064674][T24688] ? __pfx____sys_sendmsg (net/socket.c:2606) 
[2631.064822][T24688] ? usage_skip (kernel/locking/lockdep.c:2316 kernel/locking/lockdep.c:2284) 
[2631.065042][T24688] ? do_user_addr_fault (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 ./include/linux/mm.h:740 arch/x86/mm/fault.c:1339) 
[2631.065189][T24688] ? do_user_addr_fault (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 ./include/linux/mm.h:740 arch/x86/mm/fault.c:1339) 
[2631.065335][T24688] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2631.065480][T24688] ? __lock_release (kernel/locking/lockdep.c:5527) 
[2631.065700][T24688] __sys_sendmsg (net/socket.c:2649) 
[2631.065844][T24688] ? __pfx___sys_sendmsg (net/socket.c:2634) 
[2631.065990][T24688] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[2631.066138][T24688] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[2631.066355][T24688] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[ 2631.066533][T24688] RIP: 0033:0x7f99266c29a7
[ 2631.066682][T24688] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
All code
========
   0:	0a 00                	or     (%rax),%al
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b9                	jmp    0xffffffffffffffc9
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 2e 00 00 00       	mov    $0x2e,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  3b:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  11:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)
[ 2631.067275][T24688] RSP: 002b:00007ffd7ebe8388 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 2631.067505][T24688] RAX: ffffffffffffffda RBX: 00007ffd7ebe8ee0 RCX: 00007f99266c29a7
[ 2631.067796][T24688] RDX: 0000000000000000 RSI: 00007ffd7ebe83f0 RDI: 0000000000000005
[ 2631.068015][T24688] RBP: 00007ffd7ebe88b0 R08: 00000000336b6910 R09: 0000000000000000
[ 2631.068303][T24688] R10: 00007f992657b708 R11: 0000000000000246 R12: 00000000336b6918


Finger prints:
nexthop_create_group:rtm_new_nexthop:rtnetlink_rcv_msg:netlink_rcv_skb:netlink_unicast
kasan_report:kasan_check_range:nexthop_create_group:rtm_new_nexthop:rtnetlink_rcv_msg