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: 5937 at net/ipv6/route.c:4803 rt6_multipath_rebalance+0x455/0x8b0 net/ipv6/route.c:4803
Modules linked in:
CPU: 1 UID: 0 PID: 5937 Comm: kworker/u8:8 Not tainted 6.15.0-rc5-syzkaller-00022-g01f95500a162 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
Workqueue: netns cleanup_net
RIP: 0010:rt6_multipath_rebalance+0x455/0x8b0 net/ipv6/route.c:4803
Code: ff ff 44 89 e1 80 e1 07 38 c1 0f 8c 85 fe ff ff 4c 89 e7 e8 9d 25 13 f8 e9 78 fe ff ff e8 93 31 b1 f7 eb 05 e8 8c 31 b1 f7 90 <0f> 0b 90 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d e9 30 a2 01 f7
RSP: 0018:ffffc90004846fa0 EFLAGS: 00010293
RAX: ffffffff8a0e9ebd RBX: ffff88807cb2c800 RCX: ffff88802fab8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000908dec R12: ffff88807cb2c8ce
R13: ffff88807cb2c890 R14: 0000000000000000 R15: 1ffff1100f965912
FS:  0000000000000000(0000) GS:ffff8881261cb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ca2ae06950 CR3: 0000000060cb0000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 fib6_ifdown+0x401/0x4c0 net/ipv6/route.c:4923
 fib6_clean_node+0x24d/0x590 net/ipv6/ip6_fib.c:2199
 fib6_walk_continue+0x67b/0x910 net/ipv6/ip6_fib.c:2124
 fib6_walk+0x149/0x290 net/ipv6/ip6_fib.c:2172
 fib6_clean_tree net/ipv6/ip6_fib.c:2252 [inline]
 __fib6_clean_all+0x234/0x380 net/ipv6/ip6_fib.c:2268
 rt6_sync_down_dev net/ipv6/route.c:4951 [inline]
 rt6_disable_ip+0x120/0x720 net/ipv6/route.c:4956
 addrconf_ifdown+0x15d/0x1880 net/ipv6/addrconf.c:3854
 addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline]
 call_netdevice_notifiers net/core/dev.c:2228 [inline]
 dev_close_many+0x29c/0x410 net/core/dev.c:1731
 unregister_netdevice_many_notify+0x834/0x2330 net/core/dev.c:11952
 unregister_netdevice_many net/core/dev.c:12046 [inline]
 default_device_exit_batch+0x819/0x890 net/core/dev.c:12538
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x7ac/0xbd0 net/core/net_namespace.c:654
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>