------------[ cut here ]------------
WARNING: CPU: 0 PID: 20152 at net/ipv6/route.c:4857 rt6_multipath_rebalance+0x455/0x8b0 net/ipv6/route.c:4857
Modules linked in:
CPU: 0 UID: 0 PID: 20152 Comm: syz.4.4072 Not tainted 6.17.0-rc1-syzkaller-00127-g715c7a36d59f #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rt6_multipath_rebalance+0x455/0x8b0 net/ipv6/route.c:4857
Code: ff ff 44 89 e1 80 e1 07 38 c1 0f 8c 85 fe ff ff 4c 89 e7 e8 6d 9d f2 f7 e9 78 fe ff ff e8 a3 34 8f f7 eb 05 e8 9c 34 8f f7 90 <0f> 0b 90 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d e9 d5 c4 4b 01
RSP: 0018:ffffc9000e0e63e0 EFLAGS: 00010283
RAX: ffffffff8a3076ed RBX: ffff88802a581c00 RCX: 0000000000080000
RDX: ffffc9001f0be000 RSI: 00000000000032d4 RDI: 00000000000032d5
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52001c1cc74 R12: ffff88802a581cde
R13: ffff88802a581c90 R14: 0000000000000000 R15: 1ffff110054b0392
FS:  00007f95f42a46c0(0000) GS:ffff888125c1c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000041c0 CR3: 000000007f550000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 fib6_ifdown+0x401/0x4c0 net/ipv6/route.c:4977
 fib6_clean_node+0x24d/0x590 net/ipv6/ip6_fib.c:2246
 fib6_walk_continue+0x67b/0x910 net/ipv6/ip6_fib.c:2171
 fib6_walk+0x149/0x290 net/ipv6/ip6_fib.c:2219
 fib6_clean_tree net/ipv6/ip6_fib.c:2299 [inline]
 __fib6_clean_all+0x234/0x380 net/ipv6/ip6_fib.c:2315
 rt6_sync_down_dev net/ipv6/route.c:5005 [inline]
 rt6_disable_ip+0x120/0x720 net/ipv6/route.c:5010
 addrconf_ifdown+0x15d/0x1880 net/ipv6/addrconf.c:3853
 addrconf_notify+0x1bc/0x1010 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
 call_netdevice_notifiers_mtu net/core/dev.c:2304 [inline]
 netif_set_mtu_ext+0x594/0x7d0 net/core/dev.c:9674
 do_setlink+0x91a/0x41c0 net/core/rtnetlink.c:3106
 rtnl_changelink net/core/rtnetlink.c:3761 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3920 [inline]
 rtnl_newlink+0x160b/0x1c70 net/core/rtnetlink.c:4057
 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x219/0x270 net/socket.c:729
 ____sys_sendmsg+0x505/0x830 net/socket.c:2614
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
 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: 0033:0x7f95f338ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f95f42a4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f95f35b5fa0 RCX: 00007f95f338ebe9
RDX: 0000000000000000 RSI: 0000200000000940 RDI: 0000000000000008
RBP: 00007f95f3411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f95f35b6038 R14: 00007f95f35b5fa0 R15: 00007ffd73d469e8
 </TASK>