Kernel bug: WARNING in nsim_fib_event_nb
Subsystem: net
Status: open

Crash report:
IPv6: RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE
IPv6: NLM_F_CREATE should be set when creating new route
IPv6: NLM_F_CREATE should be set when creating new route
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5861 at drivers/net/netdevsim/fib.c:831 nsim_fib6_event_init drivers/net/netdevsim/fib.c:831 [inline]
WARNING: CPU: 1 PID: 5861 at drivers/net/netdevsim/fib.c:831 nsim_fib6_prepare_event drivers/net/netdevsim/fib.c:947 [inline]
WARNING: CPU: 1 PID: 5861 at drivers/net/netdevsim/fib.c:831 nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:1003 [inline]
WARNING: CPU: 1 PID: 5861 at drivers/net/netdevsim/fib.c:831 nsim_fib_event_nb+0xed8/0x1080 drivers/net/netdevsim/fib.c:1043
Modules linked in:
CPU: 1 UID: 0 PID: 5861 Comm: syz-executor316 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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+0xed8/0x1080 drivers/net/netdevsim/fib.c:1043
Code: fa be 02 00 00 00 eb 0a e8 95 97 bb fa be 01 00 00 00 4c 89 f7 e8 08 c2 b4 fd 4c 8b 64 24 08 e9 91 f4 ff ff e8 79 97 bb fa 90 <0f> 0b 90 e9 70 fb ff ff 44 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c 35
RSP: 0018:ffffc90003f7f068 EFLAGS: 00010293
RAX: ffffffff87048e47 RBX: 0000000000000002 RCX: ffff8880339dbc00
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000001
RBP: dffffc0000000000 R08: ffff888146badc2f R09: 1ffff11028d75b85
R10: dffffc0000000000 R11: ffffed1028d75b86 R12: ffff888032f28000
R13: ffffc90003f7f1e0 R14: 0000000000000001 R15: ffffc90003f7f1f8
FS:  000055556c80a380(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 0000000077970000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85
 atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223
 call_fib_notifiers+0x31/0x60 net/core/fib_notifier.c:35
 call_fib6_multipath_entry_notifiers+0xe6/0x150 net/ipv6/ip6_fib.c:425
 ip6_route_multipath_add net/ipv6/route.c:5525 [inline]
 inet6_rtm_newroute+0x12f5/0x18c0 net/ipv6/route.c:5647
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6944
 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:727
 ____sys_sendmsg+0x505/0x830 net/socket.c:2566
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
 __sys_sendmsg net/socket.c:2652 [inline]
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f748dd03fe9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 01 1a 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe9910b088 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f748dd03fe9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>