syzbot

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WARNING: CPU: 0 PID: 18387 at net/ipv6/route.c:4796 rt6_multipath_first_sibling net/ipv6/route.c:4718 [inline]
WARNING: CPU: 0 PID: 18387 at net/ipv6/route.c:4796 rt6_multipath_rebalance+0x449/0x8a0 net/ipv6/route.c:4795
Modules linked in:
CPU: 0 PID: 18387 Comm: syz.8.2945 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rt6_multipath_rebalance+0x449/0x8a0 net/ipv6/route.c:4796
Code: e8 0c be f0 f8 e9 1c fe ff ff 44 89 e1 80 e1 07 38 c1 0f 8c 85 fe ff ff 4c 89 e7 e8 d1 bd f0 f8 e9 78 fe ff ff e8 a7 a1 a0 f8 <0f> 0b eb 07 e8 9e a1 a0 f8 0f 0b 48 83 c4 10 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900040364c0 EFLAGS: 00010287
RAX: ffffffff88e02e79 RBX: ffff88807dcf9c00 RCX: 0000000000080000
RDX: ffffc90018c01000 RSI: 000000000005772f RDI: 0000000000057730
RBP: dffffc0000000000 R08: dffffc0000000000 R09: ffffed100ec09c42
R10: ffffed100ec09c42 R11: 1ffff1100ec09c41 R12: ffff88807d6094be
R13: ffff88807dcf9c80 R14: 0000000000000000 R15: 1ffff1100fb9f390
FS:  00007f52472d26c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc79e43cf98 CR3: 000000005e1c6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 fib6_ifdown+0x3ef/0x4a0 net/ipv6/route.c:4916
 fib6_clean_node+0x244/0x580 net/ipv6/ip6_fib.c:2197
 fib6_walk_continue+0x640/0x8c0 net/ipv6/ip6_fib.c:2122
 fib6_walk+0x149/0x290 net/ipv6/ip6_fib.c:2170
 fib6_clean_tree net/ipv6/ip6_fib.c:2250 [inline]
 __fib6_clean_all+0x231/0x370 net/ipv6/ip6_fib.c:2266
 rt6_sync_down_dev net/ipv6/route.c:4944 [inline]
 rt6_disable_ip+0x120/0x7f0 net/ipv6/route.c:4949
 addrconf_ifdown+0x162/0x1a10 net/ipv6/addrconf.c:3798
 addrconf_notify+0x405/0xf40 net/ipv6/addrconf.c:-1
 notifier_call_chain kernel/notifier.c:87 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455
 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline]
 call_netdevice_notifiers net/core/dev.c:2053 [inline]
 __dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1
 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8714
 do_setlink+0xc31/0x3c40 net/core/rtnetlink.c:2833
 rtnl_group_changelink net/core/rtnetlink.c:3361 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3618 [inline]
 rtnl_newlink+0x10a3/0x1ff0 net/core/rtnetlink.c:3655
 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6153
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2511
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x74d/0x8d0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x59b/0x970 net/socket.c:2519
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573
 __sys_sendmsg net/socket.c:2602 [inline]
 __do_sys_sendmsg net/socket.c:2611 [inline]
 __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f524638ebe9
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:00007f52472d2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f52465c6090 RCX: 00007f524638ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000011
RBP: 00007f5246411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52465c6128 R14: 00007f52465c6090 R15: 00007fffb74acfe8
 </TASK>