[ 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 '10.128.10.61' (ECDSA) to the list of known hosts. 2020/04/26 02:55:45 fuzzer started 2020/04/26 02:55:47 connecting to host at 10.128.0.26:37861 2020/04/26 02:55:47 checking machine... 2020/04/26 02:55:47 checking revisions... 2020/04/26 02:55:47 testing simple program... syzkaller login: [ 69.849671][ T6888] IPVS: ftp: loaded support on port[0] = 21 2020/04/26 02:55:48 building call list... [ 70.259078][ T310] tipc: TX() has been purged, node left! [ 70.302024][ T310] [ 70.304521][ T310] ============================= [ 70.310883][ T310] WARNING: suspicious RCU usage [ 70.315830][ T310] 5.7.0-rc2-next-20200424-syzkaller #0 Not tainted [ 70.324093][ T310] ----------------------------- [ 70.330104][ T310] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 70.338302][ T310] [ 70.338302][ T310] other info that might help us debug this: [ 70.338302][ T310] [ 70.369127][ T310] [ 70.369127][ T310] rcu_scheduler_active = 2, debug_locks = 1 [ 70.377277][ T310] 4 locks held by kworker/u4:5/310: [ 70.398921][ T310] #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 70.410156][ T310] #1: ffffc90001e67dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 70.421094][ T310] #2: ffffffff8a5a2c30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 70.431313][ T310] #3: ffffffff8a5aeba8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 70.441777][ T310] [ 70.441777][ T310] stack backtrace: [ 70.447686][ T310] CPU: 0 PID: 310 Comm: kworker/u4:5 Not tainted 5.7.0-rc2-next-20200424-syzkaller #0 [ 70.457233][ T310] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 70.467298][ T310] Workqueue: netns cleanup_net [ 70.472053][ T310] Call Trace: [ 70.475693][ T310] dump_stack+0x18f/0x20d [ 70.480039][ T310] ipmr_device_event+0x240/0x2b0 [ 70.484990][ T310] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 70.490895][ T310] notifier_call_chain+0xc0/0x230 [ 70.495935][ T310] call_netdevice_notifiers_info+0xb5/0x130 [ 70.502366][ T310] rollback_registered_many+0x75c/0xe70 [ 70.507931][ T310] ? netif_set_real_num_tx_queues+0x700/0x700 [ 70.514022][ T310] ? lock_downgrade+0x840/0x840 [ 70.518970][ T310] unregister_netdevice_many.part.0+0x16/0x1e0 [ 70.525124][ T310] unregister_netdevice_many+0x36/0x50 [ 70.531540][ T310] ip6gre_exit_batch_net+0x4e8/0x700 [ 70.536833][ T310] ? ip6gre_tunnel_link+0xf0/0xf0 [ 70.541860][ T310] ? rcu_read_lock_held_common+0x130/0x130 [ 70.547686][ T310] ? ip6gre_tunnel_link+0xf0/0xf0 [ 70.552719][ T310] ops_exit_list.isra.0+0x103/0x150 [ 70.557937][ T310] cleanup_net+0x511/0xa50 [ 70.562373][ T310] ? unregister_pernet_device+0x70/0x70 [ 70.567929][ T310] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 70.574087][ T310] ? _raw_spin_unlock_irq+0x1f/0x80 [ 70.579302][ T310] process_one_work+0x965/0x16a0 [ 70.584253][ T310] ? lock_release+0x800/0x800 [ 70.588932][ T310] ? pwq_dec_nr_in_flight+0x310/0x310 [ 70.594574][ T310] ? rwlock_bug.part.0+0x90/0x90 [ 70.599713][ T310] worker_thread+0x96/0xe20 [ 70.605012][ T310] ? process_one_work+0x16a0/0x16a0 [ 70.610216][ T310] kthread+0x38b/0x470 [ 70.614295][ T310] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 70.620064][ T310] ret_from_fork+0x24/0x30 [ 71.871775][ T6872] can: request_module (can-proto-0) failed. executing program [ 73.846727][ T6872] can: request_module (can-proto-0) failed. [ 73.859420][ T6872] can: request_module (can-proto-0) failed.