[ 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 '10.128.15.197' (ECDSA) to the list of known hosts. 2020/04/24 12:02:00 fuzzer started 2020/04/24 12:02:02 connecting to host at 10.128.0.26:41393 2020/04/24 12:02:02 checking machine... 2020/04/24 12:02:02 checking revisions... 2020/04/24 12:02:02 testing simple program... syzkaller login: [ 60.528505][ T6917] IPVS: ftp: loaded support on port[0] = 21 2020/04/24 12:02:02 building call list... [ 60.876920][ T121] tipc: TX() has been purged, node left! [ 60.919119][ T121] [ 60.921556][ T121] ============================= [ 60.927524][ T121] WARNING: suspicious RCU usage [ 60.932469][ T121] 5.7.0-rc2-next-20200423-syzkaller #0 Not tainted [ 60.939478][ T121] ----------------------------- [ 60.944393][ T121] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 60.952864][ T121] [ 60.952864][ T121] other info that might help us debug this: [ 60.952864][ T121] [ 60.963683][ T121] [ 60.963683][ T121] rcu_scheduler_active = 2, debug_locks = 1 [ 60.972295][ T121] 4 locks held by kworker/u4:3/121: [ 60.978008][ T121] #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 61.001428][ T121] #1: ffffc90001337dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 61.012021][ T121] #2: ffffffff8a5a3030 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 61.022039][ T121] #3: ffffffff8a5aefa8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 61.032185][ T121] [ 61.032185][ T121] stack backtrace: [ 61.038614][ T121] CPU: 0 PID: 121 Comm: kworker/u4:3 Not tainted 5.7.0-rc2-next-20200423-syzkaller #0 [ 61.048151][ T121] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.058208][ T121] Workqueue: netns cleanup_net [ 61.062963][ T121] Call Trace: [ 61.066252][ T121] dump_stack+0x18f/0x20d [ 61.073188][ T121] ipmr_device_event+0x240/0x2b0 [ 61.078215][ T121] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 61.084111][ T121] notifier_call_chain+0xc0/0x230 [ 61.089143][ T121] call_netdevice_notifiers_info+0xb5/0x130 [ 61.095122][ T121] rollback_registered_many+0x75c/0xe70 [ 61.100681][ T121] ? netif_set_real_num_tx_queues+0x700/0x700 [ 61.106763][ T121] ? lock_downgrade+0x840/0x840 [ 61.111624][ T121] unregister_netdevice_many.part.0+0x16/0x1e0 [ 61.117785][ T121] unregister_netdevice_many+0x36/0x50 [ 61.123244][ T121] ip6gre_exit_batch_net+0x4e8/0x700 [ 61.128533][ T121] ? ip6gre_tunnel_link+0xf0/0xf0 [ 61.133577][ T121] ? rcu_read_lock_held_common+0x130/0x130 [ 61.139392][ T121] ? ip6gre_tunnel_link+0xf0/0xf0 [ 61.144420][ T121] ops_exit_list.isra.0+0x103/0x150 [ 61.149641][ T121] cleanup_net+0x511/0xa50 [ 61.154059][ T121] ? unregister_pernet_device+0x70/0x70 [ 61.159605][ T121] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 61.165719][ T121] ? _raw_spin_unlock_irq+0x1f/0x80 [ 61.170945][ T121] process_one_work+0x965/0x16a0 [ 61.175899][ T121] ? lock_release+0x800/0x800 [ 61.180579][ T121] ? pwq_dec_nr_in_flight+0x310/0x310 [ 61.185955][ T121] ? rwlock_bug.part.0+0x90/0x90 [ 61.190905][ T121] worker_thread+0x96/0xe20 [ 61.195420][ T121] ? process_one_work+0x16a0/0x16a0 [ 61.200623][ T121] kthread+0x38b/0x470 [ 61.204694][ T121] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 61.210414][ T121] ret_from_fork+0x24/0x30 [ 62.297315][ T6912] can: request_module (can-proto-0) failed. executing program [ 64.352293][ T6912] can: request_module (can-proto-0) failed. [ 64.363581][ T6912] can: request_module (can-proto-0) failed.