syzbot

batman_adv: batadv0: Removing interface: batadv_slave_1
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
------------[ cut here ]------------
WARNING: CPU: 1 PID: 59 at net/ipv6/route.c:4857 rt6_multipath_rebalance.part.0+0x879/0xfd0 net/ipv6/route.c:4857
Modules linked in:
CPU: 1 UID: 0 PID: 59 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: netns cleanup_net
RIP: 0010:rt6_multipath_rebalance.part.0+0x879/0xfd0 net/ipv6/route.c:4857
Code: a4 24 58 06 00 00 31 ff 44 89 e6 e8 11 d8 7b f7 45 85 e4 0f 84 44 fe ff ff 41 bf ff ff ff ff e9 82 fe ff ff e8 b8 dc 7b f7 90 <0f> 0b 90 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f e9 a1 dc 7b f7
RSP: 0018:ffffc9000210f120 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8a3fad31
RDX: ffff888023adbc00 RSI: ffffffff8a3fb3d8 RDI: ffff8880522f6008
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88804fe1f000
R13: ffffed1009fc3e12 R14: 0000000000000100 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881247bd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000002b0030 CR3: 0000000054267000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 rt6_multipath_rebalance net/ipv6/route.c:4849 [inline]
 fib6_ifdown+0x6dc/0x8f0 net/ipv6/route.c:4977
 fib6_clean_node+0x2a7/0x5b0 net/ipv6/ip6_fib.c:2246
 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2171
 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2219
 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2299
 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2315
 rt6_sync_down_dev net/ipv6/route.c:5005 [inline]
 rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:5010
 addrconf_ifdown.isra.0+0x11d/0x1aa0 net/ipv6/addrconf.c:3853
 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3776
 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229
 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
 call_netdevice_notifiers net/core/dev.c:2281 [inline]
 netif_close_many+0x319/0x630 net/core/dev.c:1784
 unregister_netdevice_many_notify+0x563/0x24c0 net/core/dev.c:12124
 unregister_netdevice_many net/core/dev.c:12217 [inline]
 default_device_exit_batch+0x853/0xaf0 net/core/dev.c:12721
 ops_exit_list net/core/net_namespace.c:204 [inline]
 ops_undo_list+0x363/0xab0 net/core/net_namespace.c:251
 cleanup_net+0x408/0x890 net/core/net_namespace.c:682
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>