[  OK  ] Reached target Multi-User System.
[  OK  ] Reached target Graphical Interface.
         Starting Update UTMP about System Runlevel Changes...
[  OK  ] Started Update UTMP about System Runlevel Changes.
[  OK  ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch.


Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.10.13' (ECDSA) to the list of known hosts.
2020/04/25 10:22:32 fuzzer started
2020/04/25 10:22:34 connecting to host at 10.128.0.26:36315
2020/04/25 10:22:34 checking machine...
2020/04/25 10:22:34 checking revisions...
2020/04/25 10:22:34 testing simple program...
syzkaller login: [   65.413179][ T6837] IPVS: ftp: loaded support on port[0] = 21
2020/04/25 10:22:34 building call list...
[   65.757896][    T7] tipc: TX() has been purged, node left!
[   65.800402][    T7] 
[   65.802966][    T7] =============================
[   65.809316][    T7] WARNING: suspicious RCU usage
[   65.814266][    T7] 5.7.0-rc2-next-20200424-syzkaller #0 Not tainted
[   65.822255][    T7] -----------------------------
[   65.827181][    T7] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!!
[   65.836640][    T7] 
[   65.836640][    T7] other info that might help us debug this:
[   65.836640][    T7] 
[   65.848315][    T7] 
[   65.848315][    T7] rcu_scheduler_active = 2, debug_locks = 1
[   65.856481][    T7] 4 locks held by kworker/u4:0/7:
[   65.862981][    T7]  #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0
[   65.874618][    T7]  #1: ffffc90000cdfdc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0
[   65.886711][    T7]  #2: ffffffff8a5a2c30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50
[   65.897156][    T7]  #3: ffffffff8a5aeba8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700
[   65.908035][    T7] 
[   65.908035][    T7] stack backtrace:
[   65.914016][    T7] CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.7.0-rc2-next-20200424-syzkaller #0
[   65.924420][    T7] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   65.934487][    T7] Workqueue: netns cleanup_net
[   65.939264][    T7] Call Trace:
[   65.942558][    T7]  dump_stack+0x18f/0x20d
[   65.946912][    T7]  ipmr_device_event+0x240/0x2b0
[   65.951858][    T7]  ? __sanitizer_cov_trace_switch+0x45/0x70
[   65.957868][    T7]  notifier_call_chain+0xc0/0x230
[   65.962911][    T7]  call_netdevice_notifiers_info+0xb5/0x130
[   65.968809][    T7]  rollback_registered_many+0x75c/0xe70
[   65.974358][    T7]  ? netif_set_real_num_tx_queues+0x700/0x700
[   65.980439][    T7]  ? lock_downgrade+0x840/0x840
[   65.985318][    T7]  unregister_netdevice_many.part.0+0x16/0x1e0
[   65.991477][    T7]  unregister_netdevice_many+0x36/0x50
[   65.996974][    T7]  ip6gre_exit_batch_net+0x4e8/0x700
[   66.002284][    T7]  ? ip6gre_tunnel_link+0xf0/0xf0
[   66.007353][    T7]  ? rcu_read_lock_held_common+0x130/0x130
[   66.013180][    T7]  ? ip6gre_tunnel_link+0xf0/0xf0
[   66.018212][    T7]  ops_exit_list.isra.0+0x103/0x150
[   66.023503][    T7]  cleanup_net+0x511/0xa50
[   66.027936][    T7]  ? unregister_pernet_device+0x70/0x70
[   66.033506][    T7]  ? rcu_read_lock_any_held.part.0+0x50/0x50
[   66.039515][    T7]  ? _raw_spin_unlock_irq+0x1f/0x80
[   66.044734][    T7]  process_one_work+0x965/0x16a0
[   66.049697][    T7]  ? lock_release+0x800/0x800
[   66.054386][    T7]  ? pwq_dec_nr_in_flight+0x310/0x310
[   66.059766][    T7]  ? rwlock_bug.part.0+0x90/0x90
[   66.064725][    T7]  worker_thread+0x96/0xe20
[   66.069240][    T7]  ? process_one_work+0x16a0/0x16a0
[   66.074440][    T7]  kthread+0x38b/0x470
[   66.078511][    T7]  ? kthread_mod_delayed_work+0x1a0/0x1a0
[   66.084231][    T7]  ret_from_fork+0x24/0x30
[   67.296496][ T6817] can: request_module (can-proto-0) failed.
executing program
[   69.264044][ T6817] can: request_module (can-proto-0) failed.
[   69.276439][ T6817] can: request_module (can-proto-0) failed.