======================================
| [ 2416.183443][T24682] ==================================================================
| [2416.183690][T24682] 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) 
| [ 2416.183904][T24682] Read of size 4 at addr 0000000000000068 by task ip/24682
| [ 2416.184103][T24682]
[ 2416.184181][T24682] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 2416.184184][T24682] Call Trace:
[ 2416.184186][T24682]  <TASK>
[2416.184188][T24682] dump_stack_lvl (lib/dump_stack.c:123) 
[2416.184197][T24682] kasan_report (mm/kasan/report.c:636) 
[2416.184208][T24682] ? 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) 
[2416.184214][T24682] kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) 
[2416.184218][T24682] 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) 
[2416.184224][T24682] ? __pfx_nexthop_create_group (net/ipv4/nexthop.c:2686) 
[2416.184228][T24682] ? __nla_validate_parse (lib/nlattr.c:638) 
[2416.184238][T24682] rtm_new_nexthop (net/ipv4/nexthop.c:2937 net/ipv4/nexthop.c:3254) 
[2416.184241][T24682] ? 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) 
[2416.184247][T24682] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2416.184252][T24682] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2416.184265][T24682] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6952) 
[2416.184273][T24682] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2416.184276][T24682] rtnetlink_rcv_msg (net/core/rtnetlink.c:6954) 
[2416.184280][T24682] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2416.184284][T24682] ? 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) 
[2416.184286][T24682] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2416.184292][T24682] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[2416.184296][T24682] netlink_rcv_skb (net/netlink/af_netlink.c:2534) 
[2416.184301][T24682] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2416.184306][T24682] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2511) 
[2416.184313][T24682] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340) 
[2416.184317][T24682] ? 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) 
[2416.184321][T24682] netlink_unicast (net/netlink/af_netlink.c:1313 net/netlink/af_netlink.c:1339) 
[2416.184325][T24682] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1324) 
[2416.184329][T24682] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2416.184334][T24682] netlink_sendmsg (net/netlink/af_netlink.c:1883) 
[2416.184338][T24682] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1802) 
[2416.184345][T24682] ____sys_sendmsg (net/socket.c:709 net/socket.c:724 net/socket.c:2563) 
[2416.184351][T24682] ? __pfx_____sys_sendmsg (net/socket.c:2509) 
[2416.184354][T24682] ? __pfx_copy_msghdr_from_user (net/socket.c:2489) 
[2416.184363][T24682] ___sys_sendmsg (net/socket.c:2619) 
[2416.184367][T24682] ? 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) 
[2416.184370][T24682] ? __pfx____sys_sendmsg (net/socket.c:2606) 
[2416.184375][T24682] ? usage_skip (kernel/locking/lockdep.c:2316 kernel/locking/lockdep.c:2284) 
[2416.184380][T24682] ? 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) 
[2416.184387][T24682] ? 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) 
[2416.184392][T24682] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2416.184395][T24682] ? __lock_release (kernel/locking/lockdep.c:5527) 
[2416.184399][T24682] __sys_sendmsg (net/socket.c:2649) 
[2416.184403][T24682] ? __pfx___sys_sendmsg (net/socket.c:2634) 
[2416.184409][T24682] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[2416.184414][T24682] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[2416.184421][T24682] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[ 2416.184426][T24682] RIP: 0033:0x7f147a34b9a7
[ 2416.184430][T24682] 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)
[ 2416.184433][T24682] RSP: 002b:00007fffbf4b35a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 2416.184437][T24682] RAX: ffffffffffffffda RBX: 00007fffbf4b4100 RCX: 00007f147a34b9a7
[ 2416.184439][T24682] RDX: 0000000000000000 RSI: 00007fffbf4b3610 RDI: 0000000000000005
[ 2416.184441][T24682] RBP: 00007fffbf4b3ad0 R08: 0000000002ff8910 R09: 0000000000000000
[ 2416.184443][T24682] R10: 00007f147a204708 R11: 0000000000000246 R12: 0000000002ff8918
[ 2416.184445][T24682] R13: 0000000067da7dca R14: 0000000000498600 R15: 0000000002ff8910
| [ 2416.192696][T24682] Disabling lock debugging due to kernel taint
| [ 2416.192878][T24682] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [ 2416.193216][T24682] KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
| [ 2416.193642][T24682] Tainted: [B]=BAD_PAGE
[ 2416.193743][T24682] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[2416.193912][T24682] 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) 
[ 2416.194086][T24682] 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
[ 2416.194548][T24682] RSP: 0018:ffffc90009bb73c8 EFLAGS: 00010202
[ 2416.194726][T24682] RAX: 000000000000000d RBX: ffff8880156374e8 RCX: ffffffffb305e00a
[ 2416.194922][T24682] RDX: fffffbfff7185891 RSI: 0000000000000008 RDI: ffffffffb8c2c480
[ 2416.195115][T24682] RBP: 0000000000000000 R08: 0000000000000001 R09: fffffbfff7185890
[ 2416.195307][T24682] R10: ffffffffb8c2c487 R11: 205d323836343254 R12: dffffc0000000000
[ 2416.195498][T24682] R13: ffff88800987f240 R14: 0000000000000000 R15: 0000000000000068
[ 2416.195692][T24682] FS:  00007f147a13f800(0000) GS:ffff888065b80000(0000) knlGS:0000000000000000
[ 2416.195914][T24682] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2416.196077][T24682] CR2: 00007f147a39b429 CR3: 0000000017c1a001 CR4: 0000000000772ef0
[ 2416.196270][T24682] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2416.196463][T24682] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2416.196652][T24682] PKRU: 55555554
[ 2416.196749][T24682] Call Trace:
[ 2416.196845][T24682]  <TASK>
[2416.196913][T24682] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[2416.197017][T24682] ? exc_general_protection (arch/x86/kernel/traps.c:751 arch/x86/kernel/traps.c:693) 
[2416.197170][T24682] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[2416.197302][T24682] ? add_taint (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 kernel/panic.c:605) 
[2416.197405][T24682] ? 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) 
[2416.197538][T24682] ? 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) 
[2416.197670][T24682] ? __pfx_nexthop_create_group (net/ipv4/nexthop.c:2686) 
[2416.197800][T24682] ? __nla_validate_parse (lib/nlattr.c:638) 
[2416.197932][T24682] rtm_new_nexthop (net/ipv4/nexthop.c:2937 net/ipv4/nexthop.c:3254) 
[2416.198066][T24682] ? 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) 
[2416.198197][T24682] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2416.198328][T24682] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2416.198465][T24682] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6952) 
[2416.198596][T24682] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2416.198725][T24682] rtnetlink_rcv_msg (net/core/rtnetlink.c:6954) 
[2416.198861][T24682] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2416.198991][T24682] ? 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) 
[2416.199121][T24682] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2416.199225][T24682] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[2416.199355][T24682] netlink_rcv_skb (net/netlink/af_netlink.c:2534) 
[2416.199485][T24682] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2416.199616][T24682] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2511) 
[2416.199749][T24682] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340) 
[2416.199878][T24682] ? 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) 
[2416.200008][T24682] netlink_unicast (net/netlink/af_netlink.c:1313 net/netlink/af_netlink.c:1339) 
[2416.200142][T24682] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1324) 
[2416.200271][T24682] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2416.200403][T24682] netlink_sendmsg (net/netlink/af_netlink.c:1883) 
[2416.200542][T24682] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1802) 
[2416.200672][T24682] ____sys_sendmsg (net/socket.c:709 net/socket.c:724 net/socket.c:2563) 
[2416.200800][T24682] ? __pfx_____sys_sendmsg (net/socket.c:2509) 
[2416.200926][T24682] ? __pfx_copy_msghdr_from_user (net/socket.c:2489) 
[2416.201089][T24682] ___sys_sendmsg (net/socket.c:2619) 
[2416.201217][T24682] ? 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) 
[2416.201343][T24682] ? __pfx____sys_sendmsg (net/socket.c:2606) 
[2416.201470][T24682] ? usage_skip (kernel/locking/lockdep.c:2316 kernel/locking/lockdep.c:2284) 
[2416.201598][T24682] ? 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) 
[2416.201726][T24682] ? 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) 
[2416.201854][T24682] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2416.201982][T24682] ? __lock_release (kernel/locking/lockdep.c:5527) 
[2416.202110][T24682] __sys_sendmsg (net/socket.c:2649) 
[2416.202237][T24682] ? __pfx___sys_sendmsg (net/socket.c:2634) 
[2416.202365][T24682] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[2416.202493][T24682] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[2416.202622][T24682] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[ 2416.202782][T24682] RIP: 0033:0x7f147a34b9a7
[ 2416.202918][T24682] 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)
[ 2416.203456][T24682] RSP: 002b:00007fffbf4b35a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 2416.203654][T24682] RAX: ffffffffffffffda RBX: 00007fffbf4b4100 RCX: 00007f147a34b9a7
[ 2416.203933][T24682] RDX: 0000000000000000 RSI: 00007fffbf4b3610 RDI: 0000000000000005
[ 2416.204127][T24682] RBP: 00007fffbf4b3ad0 R08: 0000000002ff8910 R09: 0000000000000000
[ 2416.204391][T24682] R10: 00007f147a204708 R11: 0000000000000246 R12: 0000000002ff8918


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