Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.14' (ECDSA) to the list of known hosts. 2020/04/26 18:04:47 fuzzer started 2020/04/26 18:04:49 connecting to host at 10.128.0.26:45783 2020/04/26 18:04:49 checking machine... 2020/04/26 18:04:49 checking revisions... 2020/04/26 18:04:49 testing simple program... syzkaller login: [ 62.852195][ T6861] IPVS: ftp: loaded support on port[0] = 21 2020/04/26 18:04:49 building call list... [ 63.236392][ T99] tipc: TX() has been purged, node left! [ 63.278855][ T99] [ 63.281302][ T99] ============================= [ 63.286144][ T99] WARNING: suspicious RCU usage [ 63.291709][ T99] 5.7.0-rc2-next-20200424-syzkaller #0 Not tainted [ 63.298896][ T99] ----------------------------- [ 63.303789][ T99] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 63.312152][ T99] [ 63.312152][ T99] other info that might help us debug this: [ 63.312152][ T99] [ 63.323054][ T99] [ 63.323054][ T99] rcu_scheduler_active = 2, debug_locks = 1 [ 63.331587][ T99] 4 locks held by kworker/u4:3/99: [ 63.337158][ T99] #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 63.348263][ T99] #1: ffffc90001177dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 63.360338][ T99] #2: ffffffff8a5a2c30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 63.370178][ T99] #3: ffffffff8a5aeba8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 63.380411][ T99] [ 63.380411][ T99] stack backtrace: [ 63.386755][ T99] CPU: 0 PID: 99 Comm: kworker/u4:3 Not tainted 5.7.0-rc2-next-20200424-syzkaller #0 [ 63.396214][ T99] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 63.406273][ T99] Workqueue: netns cleanup_net [ 63.411024][ T99] Call Trace: [ 63.414312][ T99] dump_stack+0x18f/0x20d [ 63.418646][ T99] ipmr_device_event+0x240/0x2b0 [ 63.423579][ T99] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 63.429478][ T99] notifier_call_chain+0xc0/0x230 [ 63.434505][ T99] call_netdevice_notifiers_info+0xb5/0x130 [ 63.440396][ T99] rollback_registered_many+0x75c/0xe70 [ 63.445952][ T99] ? netif_set_real_num_tx_queues+0x700/0x700 [ 63.452036][ T99] ? lock_downgrade+0x840/0x840 [ 63.456896][ T99] unregister_netdevice_many.part.0+0x16/0x1e0 [ 63.463055][ T99] unregister_netdevice_many+0x36/0x50 [ 63.468519][ T99] ip6gre_exit_batch_net+0x4e8/0x700 [ 63.473808][ T99] ? ip6gre_tunnel_link+0xf0/0xf0 [ 63.478914][ T99] ? rcu_read_lock_held_common+0x130/0x130 [ 63.484719][ T99] ? ip6gre_tunnel_link+0xf0/0xf0 [ 63.489742][ T99] ops_exit_list.isra.0+0x103/0x150 [ 63.494943][ T99] cleanup_net+0x511/0xa50 [ 63.499363][ T99] ? unregister_pernet_device+0x70/0x70 [ 63.504909][ T99] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 63.512742][ T99] ? _raw_spin_unlock_irq+0x1f/0x80 [ 63.517943][ T99] process_one_work+0x965/0x16a0 [ 63.522888][ T99] ? lock_release+0x800/0x800 [ 63.527822][ T99] ? pwq_dec_nr_in_flight+0x310/0x310 [ 63.533194][ T99] ? rwlock_bug.part.0+0x90/0x90 [ 63.538154][ T99] worker_thread+0x96/0xe20 [ 63.542667][ T99] ? process_one_work+0x16a0/0x16a0 [ 63.547861][ T99] kthread+0x38b/0x470 [ 63.551927][ T99] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 63.557645][ T99] ret_from_fork+0x24/0x30 [ 64.732925][ T6838] can: request_module (can-proto-0) failed. executing program [ 66.652845][ T6838] can: request_module (can-proto-0) failed. [ 66.664233][ T6838] can: request_module (can-proto-0) failed.