[ OK ] Started Getty on tty6. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ 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... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.93' (ECDSA) to the list of known hosts. 2020/04/22 07:22:20 fuzzer started 2020/04/22 07:22:22 connecting to host at 10.128.0.26:44541 2020/04/22 07:22:22 checking machine... 2020/04/22 07:22:22 checking revisions... 2020/04/22 07:22:22 testing simple program... syzkaller login: [ 64.934258][ T6864] IPVS: ftp: loaded support on port[0] = 21 2020/04/22 07:22:23 building call list... [ 65.309687][ T21] tipc: TX() has been purged, node left! [ 65.352070][ T21] [ 65.354594][ T21] ============================= [ 65.359434][ T21] WARNING: suspicious RCU usage [ 65.366085][ T21] 5.7.0-rc2-next-20200422-syzkaller #0 Not tainted [ 65.373614][ T21] ----------------------------- [ 65.378557][ T21] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 65.388764][ T21] [ 65.388764][ T21] other info that might help us debug this: [ 65.388764][ T21] [ 65.399949][ T21] [ 65.399949][ T21] rcu_scheduler_active = 2, debug_locks = 1 [ 65.408069][ T21] 4 locks held by kworker/u4:1/21: [ 65.414463][ T21] #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 65.426102][ T21] #1: ffffc90000dd7dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 65.437018][ T21] #2: ffffffff8a5a2cb0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 65.447314][ T21] #3: ffffffff8a5aec28 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 65.457953][ T21] [ 65.457953][ T21] stack backtrace: [ 65.464844][ T21] CPU: 1 PID: 21 Comm: kworker/u4:1 Not tainted 5.7.0-rc2-next-20200422-syzkaller #0 [ 65.474295][ T21] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.484356][ T21] Workqueue: netns cleanup_net [ 65.489112][ T21] Call Trace: [ 65.492403][ T21] dump_stack+0x18f/0x20d [ 65.496735][ T21] ipmr_device_event+0x240/0x2b0 [ 65.501682][ T21] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 65.507577][ T21] notifier_call_chain+0xc0/0x230 [ 65.512602][ T21] call_netdevice_notifiers_info+0xb5/0x130 [ 65.518503][ T21] rollback_registered_many+0x75c/0xe70 [ 65.524054][ T21] ? netif_set_real_num_tx_queues+0x700/0x700 [ 65.530109][ T21] ? lock_downgrade+0x840/0x840 [ 65.534955][ T21] unregister_netdevice_many.part.0+0x16/0x1e0 [ 65.541111][ T21] unregister_netdevice_many+0x36/0x50 [ 65.546566][ T21] ip6gre_exit_batch_net+0x4e8/0x700 [ 65.551850][ T21] ? ip6gre_tunnel_link+0xf0/0xf0 [ 65.556870][ T21] ? rcu_read_lock_held_common+0x130/0x130 [ 65.562664][ T21] ? ip6gre_tunnel_link+0xf0/0xf0 [ 65.567672][ T21] ops_exit_list.isra.0+0x103/0x150 [ 65.572873][ T21] cleanup_net+0x511/0xa50 [ 65.577291][ T21] ? unregister_pernet_device+0x70/0x70 [ 65.582825][ T21] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 65.588799][ T21] ? _raw_spin_unlock_irq+0x1f/0x80 [ 65.594004][ T21] process_one_work+0x965/0x16a0 [ 65.598950][ T21] ? lock_release+0x800/0x800 [ 65.603640][ T21] ? pwq_dec_nr_in_flight+0x310/0x310 [ 65.609003][ T21] ? rwlock_bug.part.0+0x90/0x90 [ 65.613935][ T21] worker_thread+0x96/0xe20 [ 65.618440][ T21] ? process_one_work+0x16a0/0x16a0 [ 65.623626][ T21] kthread+0x38b/0x470 [ 65.627741][ T21] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 65.633452][ T21] ret_from_fork+0x24/0x30 [ 67.014731][ T6851] can: request_module (can-proto-0) failed. executing program [ 68.806678][ T6851] can: request_module (can-proto-0) failed. [ 68.818082][ T6851] can: request_module (can-proto-0) failed.