------------[ cut here ]------------
i != fen6_info->nsiblings
WARNING: drivers/net/netdevsim/fib.c:831 at nsim_fib6_event_init drivers/net/netdevsim/fib.c:831 [inline], CPU#0: syz.4.792/8864
WARNING: drivers/net/netdevsim/fib.c:831 at nsim_fib6_prepare_event drivers/net/netdevsim/fib.c:947 [inline], CPU#0: syz.4.792/8864
WARNING: drivers/net/netdevsim/fib.c:831 at nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1003 [inline], CPU#0: syz.4.792/8864
WARNING: drivers/net/netdevsim/fib.c:831 at nsim_fib_event_nb+0xbc1/0xe40 drivers/net/netdevsim/fib.c:1043, CPU#0: syz.4.792/8864
Modules linked in:
CPU: 0 UID: 0 PID: 8864 Comm: syz.4.792 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:nsim_fib6_event_init drivers/net/netdevsim/fib.c:831 [inline]
RIP: 0010:nsim_fib6_prepare_event drivers/net/netdevsim/fib.c:947 [inline]
RIP: 0010:nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1003 [inline]
RIP: 0010:nsim_fib_event_nb+0xbc1/0xe40 drivers/net/netdevsim/fib.c:1043
Code: 20 48 8b 6c 24 28 e8 4e 35 dd fa e8 49 35 dd fa 44 89 fe 44 89 ef e8 2e 2f dd fa 45 39 fd 0f 84 6a fd ff ff e8 30 35 dd fa 90 <0f> 0b 90 e9 5c fd ff ff e8 22 35 dd fa 48 c7 c7 00 b9 5b 8c e8 96
RSP: 0018:ffffc900038d7130 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffc900038d7270 RCX: 0000000000000000
RDX: ffff8880316b4980 RSI: ffffffff8729ca10 RDI: ffff888025f5c818
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880559d2000
R13: 0000000000000001 R14: ffff8880215c5b80 R15: ffff888025f5c800
FS:  00007f112ab406c0(0000) GS:ffff8880d65d9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 0000000057513000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 notifier_call_chain+0x99/0x3b0 kernel/notifier.c:85
 atomic_notifier_call_chain+0x71/0x1c0 kernel/notifier.c:223
 call_fib_notifiers+0x33/0x70 net/core/fib_notifier.c:35
 call_fib6_multipath_entry_notifiers+0x112/0x170 net/ipv6/ip6_fib.c:425
 ip6_route_multipath_add+0x128f/0x1ba0 net/ipv6/route.c:5536
 inet6_rtm_newroute+0xf5/0x160 net/ipv6/route.c:5658
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
 __sys_sendmsg+0x170/0x220 net/socket.c:2678
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1129b9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f112ab40028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1129e15fa0 RCX: 00007f1129b9aeb9
RDX: 0000000000040000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f1129c08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1129e16038 R14: 00007f1129e15fa0 R15: 00007ffd417aaed8
 </TASK>