[ OK ] Started OpenBSD Secure Shell server. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.230' (ECDSA) to the list of known hosts. 2020/03/30 12:14:14 fuzzer started 2020/03/30 12:14:16 connecting to host at 10.128.0.26:42977 2020/03/30 12:14:16 checking machine... 2020/03/30 12:14:16 checking revisions... 2020/03/30 12:14:16 testing simple program... syzkaller login: [ 66.517919][ T7039] IPVS: ftp: loaded support on port[0] = 21 2020/03/30 12:14:16 building call list... [ 66.743139][ T168] [ 66.745626][ T168] ============================= [ 66.750491][ T168] WARNING: suspicious RCU usage [ 66.762051][ T168] 5.6.0-rc7-next-20200330-syzkaller #0 Not tainted [ 66.768576][ T168] ----------------------------- [ 66.774967][ T168] net/openvswitch/conntrack.c:1898 RCU-list traversed in non-reader section!! [ 66.785401][ T168] [ 66.785401][ T168] other info that might help us debug this: [ 66.785401][ T168] [ 66.810665][ T168] [ 66.810665][ T168] rcu_scheduler_active = 2, debug_locks = 1 [ 66.820788][ T168] 3 locks held by kworker/u4:5/168: [ 66.828300][ T168] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 66.839639][ T168] #1: ffffc900014a7dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 66.850489][ T168] #2: ffffffff8a56ed30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 66.861048][ T168] [ 66.861048][ T168] stack backtrace: [ 66.868005][ T168] CPU: 1 PID: 168 Comm: kworker/u4:5 Not tainted 5.6.0-rc7-next-20200330-syzkaller #0 [ 66.877553][ T168] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.887616][ T168] Workqueue: netns cleanup_net [ 66.892374][ T168] Call Trace: [ 66.895666][ T168] dump_stack+0x188/0x20d [ 66.900003][ T168] ovs_ct_exit+0x3db/0x558 [ 66.904425][ T168] ovs_exit_net+0x1df/0xba0 [ 66.908935][ T168] ? synchronize_rcu.part.0+0xda/0xf0 [ 66.914313][ T168] ? synchronize_rcu_expedited+0x620/0x620 [ 66.920121][ T168] ? ovs_dp_cmd_del+0x270/0x270 [ 66.924978][ T168] ? ovs_dp_cmd_del+0x270/0x270 [ 66.929917][ T168] ops_exit_list.isra.0+0xa8/0x150 [ 66.935036][ T168] cleanup_net+0x511/0xa50 [ 66.939466][ T168] ? unregister_pernet_device+0x70/0x70 [ 66.945013][ T168] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 66.951006][ T168] ? _raw_spin_unlock_irq+0x1f/0x80 [ 66.956351][ T168] process_one_work+0x965/0x16a0 [ 66.961305][ T168] ? lock_release+0x800/0x800 [ 66.965993][ T168] ? pwq_dec_nr_in_flight+0x310/0x310 [ 66.971507][ T168] ? rwlock_bug.part.0+0x90/0x90 [ 66.976464][ T168] worker_thread+0x96/0xe20 [ 66.980982][ T168] ? process_one_work+0x16a0/0x16a0 [ 66.986194][ T168] kthread+0x388/0x470 [ 66.990280][ T168] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 66.996005][ T168] ret_from_fork+0x24/0x30 [ 67.202015][ T168] tipc: TX() has been purged, node left! [ 67.244339][ T168] [ 67.246839][ T168] ============================= [ 67.251683][ T168] WARNING: suspicious RCU usage [ 67.258515][ T168] 5.6.0-rc7-next-20200330-syzkaller #0 Not tainted [ 67.266114][ T168] ----------------------------- [ 67.271047][ T168] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 67.280400][ T168] [ 67.280400][ T168] other info that might help us debug this: [ 67.280400][ T168] [ 67.292134][ T168] [ 67.292134][ T168] rcu_scheduler_active = 2, debug_locks = 1 [ 67.300527][ T168] 4 locks held by kworker/u4:5/168: [ 67.307459][ T168] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 67.318961][ T168] #1: ffffc900014a7dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 67.330114][ T168] #2: ffffffff8a56ed30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 67.340503][ T168] #3: ffffffff8a57aca8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 67.352164][ T168] [ 67.352164][ T168] stack backtrace: [ 67.358089][ T168] CPU: 1 PID: 168 Comm: kworker/u4:5 Not tainted 5.6.0-rc7-next-20200330-syzkaller #0 [ 67.367764][ T168] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.379236][ T168] Workqueue: netns cleanup_net [ 67.384013][ T168] Call Trace: [ 67.387328][ T168] dump_stack+0x188/0x20d [ 67.392033][ T168] ipmr_device_event+0x240/0x2b0 [ 67.396995][ T168] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 67.402905][ T168] notifier_call_chain+0xc0/0x230 [ 67.407958][ T168] call_netdevice_notifiers_info+0xb5/0x130 [ 67.413882][ T168] rollback_registered_many+0x75c/0xe70 [ 67.419463][ T168] ? netif_set_real_num_tx_queues+0x700/0x700 [ 67.425547][ T168] ? lock_downgrade+0x840/0x840 [ 67.430431][ T168] unregister_netdevice_many.part.0+0x16/0x1e0 [ 67.436681][ T168] unregister_netdevice_many+0x36/0x50 [ 67.442167][ T168] ip6gre_exit_batch_net+0x4e8/0x700 [ 67.447566][ T168] ? ip6gre_tunnel_link+0xf0/0xf0 [ 67.455213][ T168] ? rcu_read_lock_held_common+0x130/0x130 [ 67.461041][ T168] ? ip6gre_tunnel_link+0xf0/0xf0 [ 67.466083][ T168] ops_exit_list.isra.0+0x103/0x150 [ 67.471317][ T168] cleanup_net+0x511/0xa50 [ 67.475754][ T168] ? unregister_pernet_device+0x70/0x70 [ 67.481316][ T168] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 67.487298][ T168] ? _raw_spin_unlock_irq+0x1f/0x80 [ 67.492510][ T168] process_one_work+0x965/0x16a0 [ 67.497817][ T168] ? lock_release+0x800/0x800 [ 67.502502][ T168] ? pwq_dec_nr_in_flight+0x310/0x310 [ 67.507893][ T168] ? rwlock_bug.part.0+0x90/0x90 [ 67.512864][ T168] worker_thread+0x96/0xe20 [ 67.517389][ T168] ? process_one_work+0x16a0/0x16a0 [ 67.522733][ T168] kthread+0x388/0x470 [ 67.526829][ T168] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 67.532561][ T168] ret_from_fork+0x24/0x30 [ 68.540262][ T7021] can: request_module (can-proto-0) failed. executing program [ 70.639762][ T7021] can: request_module (can-proto-0) failed. [ 70.652126][ T7021] can: request_module (can-proto-0) failed.