[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ 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. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.10.14' (ECDSA) to the list of known hosts. 2020/04/25 10:22:34 fuzzer started 2020/04/25 10:22:35 connecting to host at 10.128.0.26:37179 2020/04/25 10:22:35 checking machine... 2020/04/25 10:22:35 checking revisions... 2020/04/25 10:22:35 testing simple program... syzkaller login: [ 64.766731][ T6998] IPVS: ftp: loaded support on port[0] = 21 2020/04/25 10:22:36 building call list... [ 65.121436][ T174] tipc: TX() has been purged, node left! [ 65.173879][ T174] [ 65.176348][ T174] ============================= [ 65.181189][ T174] WARNING: suspicious RCU usage [ 65.186221][ T174] 5.7.0-rc2-next-20200424-syzkaller #0 Not tainted [ 65.193056][ T174] ----------------------------- [ 65.197991][ T174] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 65.205989][ T174] [ 65.205989][ T174] other info that might help us debug this: [ 65.205989][ T174] [ 65.216429][ T174] [ 65.216429][ T174] rcu_scheduler_active = 2, debug_locks = 1 [ 65.225046][ T174] 4 locks held by kworker/u4:4/174: [ 65.231628][ T174] #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 65.244373][ T174] #1: ffffc90001287dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 65.255616][ T174] #2: ffffffff8a5a2c30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 65.265560][ T174] #3: ffffffff8a5aeba8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 65.282087][ T174] [ 65.282087][ T174] stack backtrace: [ 65.291679][ T174] CPU: 0 PID: 174 Comm: kworker/u4:4 Not tainted 5.7.0-rc2-next-20200424-syzkaller #0 [ 65.309599][ T174] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.338170][ T174] Workqueue: netns cleanup_net [ 65.344201][ T174] Call Trace: [ 65.348008][ T174] dump_stack+0x18f/0x20d [ 65.353338][ T174] ipmr_device_event+0x240/0x2b0 [ 65.358585][ T174] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 65.365151][ T174] notifier_call_chain+0xc0/0x230 [ 65.370394][ T174] call_netdevice_notifiers_info+0xb5/0x130 [ 65.376488][ T174] rollback_registered_many+0x75c/0xe70 [ 65.382101][ T174] ? netif_set_real_num_tx_queues+0x700/0x700 [ 65.388340][ T174] ? lock_downgrade+0x840/0x840 [ 65.393292][ T174] unregister_netdevice_many.part.0+0x16/0x1e0 [ 65.399487][ T174] unregister_netdevice_many+0x36/0x50 [ 65.404962][ T174] ip6gre_exit_batch_net+0x4e8/0x700 [ 65.410259][ T174] ? ip6gre_tunnel_link+0xf0/0xf0 [ 65.415385][ T174] ? rcu_read_lock_held_common+0x130/0x130 [ 65.421206][ T174] ? ip6gre_tunnel_link+0xf0/0xf0 [ 65.426236][ T174] ops_exit_list.isra.0+0x103/0x150 [ 65.431439][ T174] cleanup_net+0x511/0xa50 [ 65.435862][ T174] ? unregister_pernet_device+0x70/0x70 [ 65.441413][ T174] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 65.447420][ T174] ? _raw_spin_unlock_irq+0x1f/0x80 [ 65.452626][ T174] process_one_work+0x965/0x16a0 [ 65.457591][ T174] ? lock_release+0x800/0x800 [ 65.462282][ T174] ? pwq_dec_nr_in_flight+0x310/0x310 [ 65.467666][ T174] ? rwlock_bug.part.0+0x90/0x90 [ 65.472627][ T174] worker_thread+0x96/0xe20 [ 65.477147][ T174] ? process_one_work+0x16a0/0x16a0 [ 65.482350][ T174] kthread+0x38b/0x470 [ 65.486419][ T174] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 65.492139][ T174] ret_from_fork+0x24/0x30 [ 66.810120][ T6986] can: request_module (can-proto-0) failed. executing program [ 68.648178][ T6986] can: request_module (can-proto-0) failed. [ 68.659658][ T6986] can: request_module (can-proto-0) failed.