[  OK  ] Started Getty on tty2.
[  OK  ] Started Serial Getty on ttyS0.
[  OK  ] Started Getty on tty1.
[  OK  ] Reached target Login Prompts.
[  OK  ] Started OpenBSD Secure Shell server.


Debian GNU/Linux 9 syzkaller ttyS0

Warning: Permanently added '10.128.1.48' (ECDSA) to the list of known hosts.
2020/04/24 12:27:09 fuzzer started
2020/04/24 12:27:10 connecting to host at 10.128.0.26:32787
2020/04/24 12:27:10 checking machine...
2020/04/24 12:27:10 checking revisions...
2020/04/24 12:27:10 testing simple program...
syzkaller login: [   65.578728][ T6855] IPVS: ftp: loaded support on port[0] = 21
2020/04/24 12:27:10 building call list...
[   65.902813][  T257] tipc: TX() has been purged, node left!
[   65.939306][  T257] 
[   65.941742][  T257] =============================
[   65.948004][  T257] WARNING: suspicious RCU usage
[   65.954228][  T257] 5.7.0-rc2-next-20200424-syzkaller #0 Not tainted
[   65.961859][  T257] -----------------------------
[   65.968083][  T257] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!!
[   65.976963][  T257] 
[   65.976963][  T257] other info that might help us debug this:
[   65.976963][  T257] 
[   65.989057][  T257] 
[   65.989057][  T257] rcu_scheduler_active = 2, debug_locks = 1
[   65.998549][  T257] 4 locks held by kworker/u4:4/257:
[   66.005336][  T257]  #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0
[   66.016677][  T257]  #1: ffffc900016b7dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0
[   66.027610][  T257]  #2: ffffffff8a5a2c30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50
[   66.037928][  T257]  #3: ffffffff8a5aeba8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700
[   66.048648][  T257] 
[   66.048648][  T257] stack backtrace:
[   66.055504][  T257] CPU: 1 PID: 257 Comm: kworker/u4:4 Not tainted 5.7.0-rc2-next-20200424-syzkaller #0
[   66.065044][  T257] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   66.075099][  T257] Workqueue: netns cleanup_net
[   66.079855][  T257] Call Trace:
[   66.083146][  T257]  dump_stack+0x18f/0x20d
[   66.087665][  T257]  ipmr_device_event+0x240/0x2b0
[   66.093156][  T257]  ? __sanitizer_cov_trace_switch+0x45/0x70
[   66.099069][  T257]  notifier_call_chain+0xc0/0x230
[   66.104136][  T257]  call_netdevice_notifiers_info+0xb5/0x130
[   66.110041][  T257]  rollback_registered_many+0x75c/0xe70
[   66.115632][  T257]  ? netif_set_real_num_tx_queues+0x700/0x700
[   66.121989][  T257]  ? lock_downgrade+0x840/0x840
[   66.127025][  T257]  unregister_netdevice_many.part.0+0x16/0x1e0
[   66.133646][  T257]  unregister_netdevice_many+0x36/0x50
[   66.139454][  T257]  ip6gre_exit_batch_net+0x4e8/0x700
[   66.145026][  T257]  ? ip6gre_tunnel_link+0xf0/0xf0
[   66.150070][  T257]  ? rcu_read_lock_held_common+0x130/0x130
[   66.155913][  T257]  ? ip6gre_tunnel_link+0xf0/0xf0
[   66.160965][  T257]  ops_exit_list.isra.0+0x103/0x150
[   66.166875][  T257]  cleanup_net+0x511/0xa50
[   66.171305][  T257]  ? unregister_pernet_device+0x70/0x70
[   66.176859][  T257]  ? rcu_read_lock_any_held.part.0+0x50/0x50
[   66.183458][  T257]  ? _raw_spin_unlock_irq+0x1f/0x80
[   66.189210][  T257]  process_one_work+0x965/0x16a0
[   66.194467][  T257]  ? lock_release+0x800/0x800
[   66.199242][  T257]  ? pwq_dec_nr_in_flight+0x310/0x310
[   66.204617][  T257]  ? rwlock_bug.part.0+0x90/0x90
[   66.209561][  T257]  worker_thread+0x96/0xe20
[   66.214073][  T257]  ? process_one_work+0x16a0/0x16a0
[   66.219273][  T257]  kthread+0x38b/0x470
[   66.223339][  T257]  ? kthread_mod_delayed_work+0x1a0/0x1a0
[   66.229058][  T257]  ret_from_fork+0x24/0x30
[   67.470389][ T6883] can: request_module (can-proto-0) failed.
executing program
[   69.440128][ T6883] can: request_module (can-proto-0) failed.
[   69.451461][ T6883] can: request_module (can-proto-0) failed.