IPv6: Can't replace route, no match found
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 10472 Comm: syz-executor4 Not tainted 4.15.0-rc5+ #178
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:fib6_add+0x730/0x13b0 net/ipv6/ip6_fib.c:1246
RSP: 0018:ffff8801bfe1f118 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 00000000fffffffe RCX: ffffffff84b8267f
RDX: 0000000000000004 RSI: ffffc90001971000 RDI: 0000000000000282
RBP: ffff8801bfe1f448 R08: 1ffff10037fc3cf4 R09: 0000000000000000
R10: ffff8801bfe1f310 R11: 0000000000000000 R12: 0000000000000020
R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000000b6
FS:  00007f245074b700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020008000 CR3: 00000001c1ed7006 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __ip6_ins_rt+0x6c/0x90 net/ipv6/route.c:1013
 ip6_route_add+0x141/0x190 net/ipv6/route.c:2799
 inet6_rtm_newroute+0x14f/0x160 net/ipv6/route.c:4085
 rtnetlink_rcv_msg+0x57f/0xb10 net/core/rtnetlink.c:4522
 netlink_rcv_skb+0x224/0x470 net/netlink/af_netlink.c:2441
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4540
 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline]
 netlink_unicast+0x4c4/0x6b0 net/netlink/af_netlink.c:1334
 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1897
 sock_sendmsg_nosec net/socket.c:628 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:638
 sock_write_iter+0x31a/0x5d0 net/socket.c:907
 call_write_iter include/linux/fs.h:1772 [inline]
 do_iter_readv_writev+0x525/0x7f0 fs/read_write.c:653
 do_iter_write+0x154/0x540 fs/read_write.c:932
 vfs_writev+0x18a/0x340 fs/read_write.c:977
 do_writev+0xfc/0x2a0 fs/read_write.c:1012
 SYSC_writev fs/read_write.c:1085 [inline]
 SyS_writev+0x27/0x30 fs/read_write.c:1082
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007f245074ac58 EFLAGS: 00000212 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 0000000000000001 RSI: 0000000020ff9ff0 RDI: 0000000000000013
RBP: 00000000000005f8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f6fe0
R13: 0000000000000001 R14: 000000000071bef0 R15: 0000000000000000
Code: b7 e4 b7 fc e8 12 29 a4 fc 85 c0 0f 85 b6 02 00 00 4d 8d 66 20 e8 a1 e4 b7 fc 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 39 09 00 00 4d 39 f5 4d 8b 7e 20 0f 95 c0 4c 
RIP: fib6_add+0x730/0x13b0 net/ipv6/ip6_fib.c:1246 RSP: ffff8801bfe1f118
---[ end trace e6c8b57d880b7c1c ]---