WARNING in fib6

similar bugs (4):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
upstream	WARNING in fib6_add net	C	8225	1963d	1986d	3/24	fixed on 2017/11/28 03:36
upstream	WARNING in fib6_add (4)		2	1059d	1075d	0/24	auto-closed as invalid on 2020/08/31 02:33
upstream	WARNING in fib6_add (2)		11	1437d	1578d	0/24	auto-closed as invalid on 2019/10/17 17:19
linux-4.19	WARNING in fib6_add		1	1326d	1326d	0/1	auto-closed as invalid on 2019/12/07 20:56

IPv6: NLM_F_REPLACE set, but no existing node found!
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WARNING: CPU: 1 PID: 6888 at net/ipv6/ip6_fib.c:1500 fib6_add+0x346e/0x3ec0 net/ipv6/ip6_fib.c:1500
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 6888 Comm: syz-executor.1 Not tainted 5.5.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:176 [inline]
 fixup_bug arch/x86/kernel/traps.c:171 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:269
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:288
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:fib6_add+0x346e/0x3ec0 net/ipv6/ip6_fib.c:1500
Code: df 48 8d bb d0 09 00 00 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 65 08 00 00 48 8b 9b d0 09 00 00 e9 c9 f6 ff ff e8 b2 cd a1 fa <0f> 0b 48 b8 00 00 00 00 00 fc ff df 48 8b 55 b0 48 c1 ea 03 80 3c
RSP: 0018:ffffc9000ac773d8 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90004889000
RDX: 00000000000086a2 RSI: ffffffff86d39fee RDI: ffff8880864051a0
RBP: ffffc9000ac774b0 R08: ffff8880a87d0040 R09: ffffed1011f32c46
R10: ffffed1011f32c45 R11: ffff88808f99622f R12: ffff88809fd46720
R13: 00000000fffffffe R14: 0000000000000000 R15: ffff88809fd46700
 __ip6_ins_rt+0x54/0x80 net/ipv6/route.c:1315
 ip6_route_add+0x5e/0x110 net/ipv6/route.c:3711
 inet6_rtm_newroute+0x16c/0x180 net/ipv6/route.c:5335
 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:672
 ____sys_sendmsg+0x753/0x880 net/socket.c:2343
 ___sys_sendmsg+0x100/0x170 net/socket.c:2397
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
 __do_sys_sendmsg net/socket.c:2439 [inline]
 __se_sys_sendmsg net/socket.c:2437 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b349
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe4d97f7c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe4d97f86d4 RCX: 000000000045b349
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000008d2 R14: 00000000004ca26a R15: 000000000075bf2c
Kernel Offset: disabled
Rebooting in 86400 seconds..