syzbot

netlink: 'syz-executor.5': attribute type 18 has an invalid length.
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BUG: KCSAN: data-race in cake_dump_stats / cake_enqueue

write to 0xffff8881b1619834 of 4 bytes by task 904 on cpu 0:
 cake_enqueue+0x3484/0x48a0 net/sched/sch_cake.c:1740
 dev_qdisc_enqueue net/core/dev.c:3739 [inline]
 __dev_xmit_skb net/core/dev.c:3828 [inline]
 __dev_queue_xmit+0x83b/0x1e20 net/core/dev.c:4306
 dev_queue_xmit include/linux/netdevice.h:3082 [inline]
 neigh_resolve_output+0x3bf/0x430 net/core/neighbour.c:1554
 neigh_output include/net/neighbour.h:542 [inline]
 ip6_finish_output2+0x9c0/0xc50 net/ipv6/ip6_output.c:135
 __ip6_finish_output net/ipv6/ip6_output.c:196 [inline]
 ip6_finish_output+0x3a0/0x4f0 net/ipv6/ip6_output.c:207
 NF_HOOK_COND include/linux/netfilter.h:293 [inline]
 ip6_output+0xeb/0x220 net/ipv6/ip6_output.c:228
 dst_output include/net/dst.h:458 [inline]
 NF_HOOK include/linux/netfilter.h:304 [inline]
 mld_sendpack+0x438/0x6a0 net/ipv6/mcast.c:1818
 mld_send_cr net/ipv6/mcast.c:2119 [inline]
 mld_ifc_work+0x519/0x7b0 net/ipv6/mcast.c:2651
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
 worker_thread+0x525/0x730 kernel/workqueue.c:2784
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

read to 0xffff8881b1619834 of 4 bytes by task 13972 on cpu 1:
 cake_dump_stats+0xcf1/0x1000 net/sched/sch_cake.c:2929
 tc_fill_qdisc+0x6da/0x9a0 net/sched/sch_api.c:966
 qdisc_notify+0x18c/0x230 net/sched/sch_api.c:1024
 tc_modify_qdisc+0xffe/0x1040 net/sched/sch_api.c:1719
 rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6444
 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2545
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6462
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0x589/0x650 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0x66e/0x770 net/netlink/af_netlink.c:1910
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x37c/0x4d0 net/socket.c:2558
 ___sys_sendmsg net/socket.c:2612 [inline]
 __sys_sendmsg+0x1e9/0x270 net/socket.c:2641
 __do_sys_sendmsg net/socket.c:2650 [inline]
 __se_sys_sendmsg net/socket.c:2648 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2648
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000 -> 0x0000006e

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13972 Comm: syz-executor.5 Not tainted 6.6.0-rc4-syzkaller-00229-g82714078aee4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
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