[ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.237' (ECDSA) to the list of known hosts. 2020/04/21 11:38:26 fuzzer started 2020/04/21 11:38:27 connecting to host at 10.128.0.26:38969 2020/04/21 11:38:27 checking machine... 2020/04/21 11:38:27 checking revisions... 2020/04/21 11:38:27 testing simple program... syzkaller login: [ 60.230985][ T6870] IPVS: ftp: loaded support on port[0] = 21 2020/04/21 11:38:28 building call list... [ 60.599722][ T184] tipc: TX() has been purged, node left! [ 60.643477][ T184] [ 60.645932][ T184] ============================= [ 60.652379][ T184] WARNING: suspicious RCU usage [ 60.657337][ T184] 5.7.0-rc2-next-20200421-syzkaller #0 Not tainted [ 60.665341][ T184] ----------------------------- [ 60.682728][ T184] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 60.691748][ T184] [ 60.691748][ T184] other info that might help us debug this: [ 60.691748][ T184] [ 60.703181][ T184] [ 60.703181][ T184] rcu_scheduler_active = 2, debug_locks = 1 [ 60.712837][ T184] 4 locks held by kworker/u4:3/184: [ 60.718122][ T184] #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 60.730010][ T184] #1: ffffc900016f7dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 60.741047][ T184] #2: ffffffff8a5a2b70 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 60.751510][ T184] #3: ffffffff8a5aeae8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 60.763249][ T184] [ 60.763249][ T184] stack backtrace: [ 60.769207][ T184] CPU: 1 PID: 184 Comm: kworker/u4:3 Not tainted 5.7.0-rc2-next-20200421-syzkaller #0 [ 60.778740][ T184] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.788802][ T184] Workqueue: netns cleanup_net [ 60.793565][ T184] Call Trace: [ 60.796858][ T184] dump_stack+0x188/0x20d [ 60.801188][ T184] ipmr_device_event+0x240/0x2b0 [ 60.806125][ T184] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 60.812022][ T184] notifier_call_chain+0xc0/0x230 [ 60.817056][ T184] call_netdevice_notifiers_info+0xb5/0x130 [ 60.822956][ T184] rollback_registered_many+0x75c/0xe70 [ 60.828520][ T184] ? netif_set_real_num_tx_queues+0x700/0x700 [ 60.834599][ T184] ? lock_downgrade+0x840/0x840 [ 60.839455][ T184] unregister_netdevice_many.part.0+0x16/0x1e0 [ 60.845737][ T184] unregister_netdevice_many+0x36/0x50 [ 60.851195][ T184] ip6gre_exit_batch_net+0x4e8/0x700 [ 60.856488][ T184] ? ip6gre_tunnel_link+0xf0/0xf0 [ 60.861510][ T184] ? rcu_read_lock_held_common+0x130/0x130 [ 60.867329][ T184] ? ip6gre_tunnel_link+0xf0/0xf0 [ 60.872367][ T184] ops_exit_list.isra.0+0x103/0x150 [ 60.877584][ T184] cleanup_net+0x511/0xa50 [ 60.882023][ T184] ? unregister_pernet_device+0x70/0x70 [ 60.887568][ T184] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 60.893550][ T184] ? _raw_spin_unlock_irq+0x1f/0x80 [ 60.898757][ T184] process_one_work+0x965/0x16a0 [ 60.903703][ T184] ? lock_release+0x800/0x800 [ 60.908377][ T184] ? pwq_dec_nr_in_flight+0x310/0x310 [ 60.913761][ T184] ? rwlock_bug.part.0+0x90/0x90 [ 60.918709][ T184] worker_thread+0x96/0xe20 [ 60.923224][ T184] ? process_one_work+0x16a0/0x16a0 [ 60.928418][ T184] kthread+0x38b/0x470 [ 60.932503][ T184] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 60.938242][ T184] ret_from_fork+0x24/0x30 [ 62.067160][ T6855] can: request_module (can-proto-0) failed. executing program [ 64.075966][ T6855] can: request_module (can-proto-0) failed. [ 64.087475][ T6855] can: request_module (can-proto-0) failed.