syzbot

batman_adv: batadv0: Removing interface: batadv_slave_1
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
------------[ cut here ]------------
WARNING: CPU: 1 PID: 3786 at net/ipv6/route.c:4856 rt6_multipath_rebalance.part.0+0x879/0xfd0 net/ipv6/route.c:4856
Modules linked in:
CPU: 1 UID: 0 PID: 3786 Comm: kworker/u8:8 Not tainted 6.16.0-rc2-syzkaller-00024-g9afe652958c3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: netns cleanup_net
RIP: 0010:rt6_multipath_rebalance.part.0+0x879/0xfd0 net/ipv6/route.c:4856
Code: a4 24 54 06 00 00 31 ff 44 89 e6 e8 c1 91 90 f7 45 85 e4 0f 84 44 fe ff ff 41 bf ff ff ff ff e9 82 fe ff ff e8 68 96 90 f7 90 <0f> 0b 90 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f e9 51 96 90 f7
RSP: 0018:ffffc9000c3570c0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8a2b7e6a
RDX: ffff888032e9da00 RSI: ffffffff8a2b84d8 RDI: ffff888055c3b808
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888055c3b800
R13: ffffed100ab87712 R14: 0000000000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88812485a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3e7d088286 CR3: 0000000058ddf000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 rt6_multipath_rebalance net/ipv6/route.c:4848 [inline]
 fib6_ifdown+0x6dc/0x8f0 net/ipv6/route.c:4976
 fib6_clean_node+0x2a7/0x5b0 net/ipv6/ip6_fib.c:2252
 fib6_walk_continue+0x452/0x8d0 net/ipv6/ip6_fib.c:2177
 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2225
 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2305
 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2321
 rt6_sync_down_dev net/ipv6/route.c:5004 [inline]
 rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:5009
 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3857
 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3780
 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2230
 call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
 call_netdevice_notifiers net/core/dev.c:2282 [inline]
 dev_close_many+0x319/0x630 net/core/dev.c:1785
 unregister_netdevice_many_notify+0x578/0x2700 net/core/dev.c:12047
 unregister_netdevice_many net/core/dev.c:12140 [inline]
 default_device_exit_batch+0x853/0xaf0 net/core/dev.c:12644
 ops_exit_list net/core/net_namespace.c:206 [inline]
 ops_undo_list+0x363/0xab0 net/core/net_namespace.c:253
 cleanup_net+0x408/0x890 net/core/net_namespace.c:686
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 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>