Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.1.111' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   29.145536] 
[   29.147447] =============================
[   29.151580] WARNING: suspicious RCU usage
[   29.157913] 4.14.230-syzkaller #0 Not tainted
[   29.162426] -----------------------------
[   29.167630] net/sched/act_sample.c:95 suspicious rcu_dereference_protected() usage!
[   29.175956] 
[   29.175956] other info that might help us debug this:
[   29.175956] 
[   29.184856] 
[   29.184856] rcu_scheduler_active = 2, debug_locks = 1
[   29.191512] 1 lock held by syz-executor268/7972:
[   29.197087]  #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85c7627d>] rtnetlink_rcv_msg+0x31d/0xb10
[   29.206248] 
[   29.206248] stack backtrace:
[   29.210740] CPU: 0 PID: 7972 Comm: syz-executor268 Not tainted 4.14.230-syzkaller #0
[   29.218607] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   29.227944] Call Trace:
[   29.230530]  dump_stack+0x1b2/0x281
[   29.234145]  tcf_sample_init+0x71c/0x8c0
[   29.238294]  ? tcf_sample_cleanup_rcu+0x60/0x60
[   29.242972]  tcf_action_init_1+0x51a/0x9e0
[   29.247194]  ? tcf_action_dump_old+0x80/0x80
[   29.251586]  ? nla_parse+0x157/0x1f0
[   29.255283]  tcf_action_init+0x26d/0x400
[   29.259352]  ? tcf_action_init_1+0x9e0/0x9e0
[   29.263761]  ? memset+0x20/0x40
[   29.267019]  ? nla_parse+0x157/0x1f0
[   29.271058]  tc_ctl_action+0x2e3/0x510
[   29.274938]  ? tca_action_gd+0x790/0x790
[   29.279093]  ? rtnetlink_rcv_msg+0x2e8/0xb10
[   29.283504]  ? tca_action_gd+0x790/0x790
[   29.287550]  rtnetlink_rcv_msg+0x3be/0xb10
[   29.291778]  ? rtnl_calcit.isra.0+0x3a0/0x3a0
[   29.296255]  ? __netlink_lookup+0x345/0x5d0
[   29.301288]  netlink_rcv_skb+0x125/0x390
[   29.306839]  ? rtnl_calcit.isra.0+0x3a0/0x3a0
[   29.311324]  ? netlink_ack+0x9a0/0x9a0
[   29.315194]  netlink_unicast+0x437/0x610
[   29.319234]  ? netlink_sendskb+0xd0/0xd0
[   29.323276]  ? __check_object_size+0x179/0x230
[   29.327860]  netlink_sendmsg+0x62e/0xb80
[   29.331900]  ? nlmsg_notify+0x170/0x170
[   29.335874]  ? kernel_recvmsg+0x210/0x210
[   29.340005]  ? security_socket_sendmsg+0x83/0xb0
[   29.344743]  ? nlmsg_notify+0x170/0x170
[   29.348708]  sock_sendmsg+0xb5/0x100
[   29.352425]  ___sys_sendmsg+0x6c8/0x800
[   29.356378]  ? copy_msghdr_from_user+0x3b0/0x3b0
[   29.361128]  ? lock_downgrade+0x740/0x740
[   29.365266]  ? __lru_cache_add+0x178/0x250
[   29.369483]  ? do_raw_spin_unlock+0x164/0x220
[   29.373980]  ? _raw_spin_unlock+0x29/0x40
[   29.378119]  ? do_huge_pmd_anonymous_page+0x72e/0x1700
[   29.383387]  ? prep_transhuge_page+0xa0/0xa0
[   29.387973]  ? __lockdep_init_map+0x100/0x560
[   29.392470]  ? __handle_mm_fault+0x80f/0x4620
[   29.396947]  ? lock_downgrade+0x740/0x740
[   29.401130]  ? vm_insert_page+0x7c0/0x7c0
[   29.405286]  ? __fdget+0x167/0x1f0
[   29.408845]  ? sockfd_lookup_light+0xb2/0x160
[   29.413333]  __sys_sendmsg+0xa3/0x120
[   29.417149]  ? SyS_shutdown+0x160/0x160
[   29.421109]  ? up_read+0x17/0x30
[   29.424458]  ? __do_page_fault+0x159/0xad0
[   29.428675]  SyS_sendmsg+0x27/0x40
[   29.432194]  ? __sys_sendmsg+0x120/0x120
[   29.436324]  do_syscall_64+0x1d5/0x640
[   29.440201]  entry_SYSCALL_64_after_hwframe+0x46/0xbb
[   29.445400] RIP: