======================================
| [ 2660.855311][T24689] ==================================================================
| [2660.855551][T24689] 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) 
| [ 2660.855775][T24689] Read of size 4 at addr 0000000000000068 by task ip/24689
| [ 2660.855982][T24689]
[ 2660.856061][T24689] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 2660.856064][T24689] Call Trace:
[ 2660.856065][T24689]  <TASK>
[2660.856070][T24689] dump_stack_lvl (lib/dump_stack.c:123) 
[2660.856078][T24689] kasan_report (mm/kasan/report.c:636) 
[2660.856085][T24689] ? 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) 
[2660.856091][T24689] kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) 
[2660.856095][T24689] 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) 
[2660.856102][T24689] ? __pfx_nexthop_create_group (net/ipv4/nexthop.c:2686) 
[2660.856106][T24689] ? __nla_validate_parse (lib/nlattr.c:638) 
[2660.856114][T24689] rtm_new_nexthop (net/ipv4/nexthop.c:2937 net/ipv4/nexthop.c:3254) 
[2660.856117][T24689] ? 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) 
[2660.856122][T24689] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2660.856127][T24689] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2660.856140][T24689] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6952) 
[2660.856146][T24689] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2660.856149][T24689] rtnetlink_rcv_msg (net/core/rtnetlink.c:6954) 
[2660.856153][T24689] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2660.856156][T24689] ? 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) 
[2660.856159][T24689] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2660.856165][T24689] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[2660.856169][T24689] netlink_rcv_skb (net/netlink/af_netlink.c:2534) 
[2660.856174][T24689] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2660.856178][T24689] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2511) 
[2660.856186][T24689] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340) 
[2660.856190][T24689] ? 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) 
[2660.856194][T24689] netlink_unicast (net/netlink/af_netlink.c:1313 net/netlink/af_netlink.c:1339) 
[2660.856198][T24689] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1324) 
[2660.856201][T24689] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2660.856206][T24689] netlink_sendmsg (net/netlink/af_netlink.c:1883) 
[2660.856210][T24689] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1802) 
[2660.856217][T24689] ____sys_sendmsg (net/socket.c:709 net/socket.c:724 net/socket.c:2563) 
[2660.856222][T24689] ? __pfx_____sys_sendmsg (net/socket.c:2509) 
[2660.856225][T24689] ? __pfx_copy_msghdr_from_user (net/socket.c:2489) 
[2660.856234][T24689] ___sys_sendmsg (net/socket.c:2619) 
[2660.856237][T24689] ? 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) 
[2660.856240][T24689] ? __pfx____sys_sendmsg (net/socket.c:2606) 
[2660.856246][T24689] ? usage_skip (kernel/locking/lockdep.c:2316 kernel/locking/lockdep.c:2284) 
[2660.856251][T24689] ? 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) 
[2660.856256][T24689] ? 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) 
[2660.856261][T24689] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2660.856264][T24689] ? __lock_release (kernel/locking/lockdep.c:5527) 
[2660.856268][T24689] __sys_sendmsg (net/socket.c:2649) 
[2660.856271][T24689] ? __pfx___sys_sendmsg (net/socket.c:2634) 
[2660.856278][T24689] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[2660.856283][T24689] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[2660.856287][T24689] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[ 2660.856291][T24689] RIP: 0033:0x7f5f1beee9a7
[ 2660.856295][T24689] 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)
[ 2660.856298][T24689] RSP: 002b:00007ffdb51309e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 2660.856301][T24689] RAX: ffffffffffffffda RBX: 00007ffdb5131540 RCX: 00007f5f1beee9a7
[ 2660.856303][T24689] RDX: 0000000000000000 RSI: 00007ffdb5130a50 RDI: 0000000000000005
[ 2660.856305][T24689] RBP: 00007ffdb5130f10 R08: 0000000025ca2910 R09: 0000000000000000
[ 2660.856307][T24689] R10: 00007f5f1bda7708 R11: 0000000000000246 R12: 0000000025ca2918
[ 2660.856309][T24689] R13: 0000000067da4122 R14: 0000000000498600 R15: 0000000025ca2910
| [ 2660.865085][T24689] Disabling lock debugging due to kernel taint
| [ 2660.865272][T24689] Oops: general protection fault, probably for non-canonical address 0xdffffc000000000d: 0000 [#1] PREEMPT SMP KASAN NOPTI
| [ 2660.865616][T24689] KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
| [ 2660.866060][T24689] Tainted: [B]=BAD_PAGE
[ 2660.866171][T24689] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[2660.866348][T24689] 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) 
[ 2660.866531][T24689] 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
[ 2660.867009][T24689] RSP: 0018:ffffc900096273c8 EFLAGS: 00010202
[ 2660.867185][T24689] RAX: 000000000000000d RBX: ffff88800d0818e8 RCX: ffffffffb5e5e00a
[ 2660.867392][T24689] RDX: fffffbfff7745891 RSI: 0000000000000008 RDI: ffffffffbba2c480
[ 2660.867598][T24689] RBP: 0000000000000000 R08: 0000000000000001 R09: fffffbfff7745890
[ 2660.867800][T24689] R10: ffffffffbba2c487 R11: 205d393836343254 R12: dffffc0000000000
[ 2660.868004][T24689] R13: ffff88800a6d0340 R14: 0000000000000000 R15: 0000000000000068
[ 2660.868212][T24689] FS:  00007f5f1bce2800(0000) GS:ffff88806cf80000(0000) knlGS:0000000000000000
[ 2660.868452][T24689] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2660.868626][T24689] CR2: 00007f5f1bf3e429 CR3: 0000000015fb6004 CR4: 0000000000772ef0
[ 2660.868833][T24689] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2660.869043][T24689] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2660.869252][T24689] PKRU: 55555554
[ 2660.869358][T24689] Call Trace:
[ 2660.869463][T24689]  <TASK>
[2660.869534][T24689] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460) 
[2660.869643][T24689] ? exc_general_protection (arch/x86/kernel/traps.c:751 arch/x86/kernel/traps.c:693) 
[2660.869785][T24689] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:617) 
[2660.869931][T24689] ? add_taint (./arch/x86/include/asm/bitops.h:60 ./include/asm-generic/bitops/instrumented-atomic.h:29 kernel/panic.c:605) 
[2660.870039][T24689] ? 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) 
[2660.870176][T24689] ? 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) 
[2660.870317][T24689] ? __pfx_nexthop_create_group (net/ipv4/nexthop.c:2686) 
[2660.870455][T24689] ? __nla_validate_parse (lib/nlattr.c:638) 
[2660.870595][T24689] rtm_new_nexthop (net/ipv4/nexthop.c:2937 net/ipv4/nexthop.c:3254) 
[2660.870734][T24689] ? 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) 
[2660.870875][T24689] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2660.870982][T24689] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2660.871127][T24689] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6952) 
[2660.871267][T24689] ? __pfx_rtm_new_nexthop (net/ipv4/nexthop.c:3225) 
[2660.871404][T24689] rtnetlink_rcv_msg (net/core/rtnetlink.c:6954) 
[2660.871542][T24689] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2660.871680][T24689] ? 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) 
[2660.871815][T24689] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[2660.871924][T24689] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[2660.872060][T24689] netlink_rcv_skb (net/netlink/af_netlink.c:2534) 
[2660.872201][T24689] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[2660.872337][T24689] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2511) 
[2660.872480][T24689] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340) 
[2660.872615][T24689] ? 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) 
[2660.872759][T24689] netlink_unicast (net/netlink/af_netlink.c:1313 net/netlink/af_netlink.c:1339) 
[2660.872903][T24689] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1324) 
[2660.873040][T24689] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2660.873179][T24689] netlink_sendmsg (net/netlink/af_netlink.c:1883) 
[2660.873317][T24689] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1802) 
[2660.873458][T24689] ____sys_sendmsg (net/socket.c:709 net/socket.c:724 net/socket.c:2563) 
[2660.873595][T24689] ? __pfx_____sys_sendmsg (net/socket.c:2509) 
[2660.873729][T24689] ? __pfx_copy_msghdr_from_user (net/socket.c:2489) 
[2660.873901][T24689] ___sys_sendmsg (net/socket.c:2619) 
[2660.874036][T24689] ? 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) 
[2660.874173][T24689] ? __pfx____sys_sendmsg (net/socket.c:2606) 
[2660.874312][T24689] ? usage_skip (kernel/locking/lockdep.c:2316 kernel/locking/lockdep.c:2284) 
[2660.874451][T24689] ? 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) 
[2660.874588][T24689] ? 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) 
[2660.874728][T24689] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[2660.874869][T24689] ? __lock_release (kernel/locking/lockdep.c:5527) 
[2660.875007][T24689] __sys_sendmsg (net/socket.c:2649) 
[2660.875144][T24689] ? __pfx___sys_sendmsg (net/socket.c:2634) 
[2660.875282][T24689] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[2660.875419][T24689] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[2660.875555][T24689] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[ 2660.875797][T24689] RIP: 0033:0x7f5f1beee9a7
[ 2660.875945][T24689] 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)
[ 2660.876498][T24689] RSP: 002b:00007ffdb51309e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 2660.876703][T24689] RAX: ffffffffffffffda RBX: 00007ffdb5131540 RCX: 00007f5f1beee9a7
[ 2660.876981][T24689] RDX: 0000000000000000 RSI: 00007ffdb5130a50 RDI: 0000000000000005
[ 2660.877185][T24689] RBP: 00007ffdb5130f10 R08: 0000000025ca2910 R09: 0000000000000000
[ 2660.877392][T24689] R10: 00007f5f1bda7708 R11: 0000000000000246 R12: 0000000025ca2918


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