Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.0.231' (ECDSA) to the list of known hosts.
executing program
syzkaller login: [   30.046299] 
[   30.048058] =============================
[   30.052203] WARNING: suspicious RCU usage
[   30.056348] 4.14.224-syzkaller #0 Not tainted
[   30.062281] -----------------------------
[   30.066452] net/sched/act_sample.c:95 suspicious rcu_dereference_protected() usage!
[   30.075152] 
[   30.075152] other info that might help us debug this:
[   30.075152] 
[   30.084427] 
[   30.084427] rcu_scheduler_active = 2, debug_locks = 1
[   30.091685] 1 lock held by syz-executor873/7960:
[   30.096458]  #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85c6224d>] rtnetlink_rcv_msg+0x31d/0xb10
[   30.105948] 
[   30.105948] stack backtrace:
[   30.111605] CPU: 1 PID: 7960 Comm: syz-executor873 Not tainted 4.14.224-syzkaller #0
[   30.119485] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   30.129135] Call Trace:
[   30.131727]  dump_stack+0x1b2/0x281
[   30.135337]  tcf_sample_init+0x71c/0x8c0
[   30.139392]  ? tcf_sample_cleanup_rcu+0x60/0x60
[   30.144091]  tcf_action_init_1+0x51a/0x9e0
[   30.148430]  ? tcf_action_dump_old+0x80/0x80
[   30.152849]  ? nla_parse+0x157/0x1f0
[   30.156554]  tcf_action_init+0x26d/0x400
[   30.160610]  ? tcf_action_init_1+0x9e0/0x9e0
[   30.165025]  ? memset+0x20/0x40
[   30.168289]  ? nla_parse+0x157/0x1f0
[   30.177134]  tc_ctl_action+0x2e3/0x510
[   30.181026]  ? tca_action_gd+0x790/0x790
[   30.185086]  ? rtnetlink_rcv_msg+0x2e8/0xb10
[   30.189539]  ? tca_action_gd+0x790/0x790
[   30.193588]  rtnetlink_rcv_msg+0x3be/0xb10
[   30.197824]  ? rtnl_calcit.isra.0+0x3a0/0x3a0
[   30.202302]  ? __netlink_lookup+0x345/0x5d0
[   30.206609]  netlink_rcv_skb+0x125/0x390
[   30.210655]  ? rtnl_calcit.isra.0+0x3a0/0x3a0
[   30.215156]  ? netlink_ack+0x9a0/0x9a0
[   30.219071]  netlink_unicast+0x437/0x610
[   30.223136]  ? netlink_sendskb+0xd0/0xd0
[   30.227279]  ? __check_object_size+0x179/0x230
[   30.231869]  netlink_sendmsg+0x62e/0xb80
[   30.235918]  ? nlmsg_notify+0x170/0x170
[   30.239913]  ? kernel_recvmsg+0x210/0x210
[   30.244058]  ? security_socket_sendmsg+0x83/0xb0
[   30.248806]  ? nlmsg_notify+0x170/0x170
[   30.252780]  sock_sendmsg+0xb5/0x100
[   30.256493]  ___sys_sendmsg+0x6c8/0x800
[   30.260468]  ? copy_msghdr_from_user+0x3b0/0x3b0
[   30.265207]  ? lock_downgrade+0x740/0x740
[   30.269338]  ? do_raw_spin_unlock+0x164/0x220
[   30.273816]  ? _raw_spin_unlock+0x29/0x40
[   30.277959]  ? do_huge_pmd_anonymous_page+0x72e/0x1700
[   30.283233]  ? prep_transhuge_page+0xa0/0xa0
[   30.287638]  ? __handle_mm_fault+0x80f/0x4620
[   30.292147]  ? vm_insert_page+0x7c0/0x7c0
[   30.296287]  ? __fdget+0x167/0x1f0
[   30.299866]  ? sockfd_lookup_light+0xb2/0x160
[   30.304360]  __sys_sendmsg+0xa3/0x120
[   30.308157]  ? SyS_shutdown+0x160/0x160
[   30.312118]  ? up_read+0x17/0x30
[   30.315469]  ? __do_page_fault+0x159/0xad0
[   30.319689]  SyS_sendmsg+0x27/0x40
[   30.323213]  ? __sys_sendmsg+0x120/0x120
[   30.327272]  do_syscall_64+0x1d5/0x640
[   30.331148]  entry_SYSCALL_64_after_hwframe+0x46/0xbb
[   30.336442] RIP: 0033:0x43f0c9
[   30.339619] RSP: 002b:00007ffcaf95c948 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
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