[ 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... Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.47' (ECDSA) to the list of known hosts. 2020/04/26 18:04:50 fuzzer started 2020/04/26 18:04:51 connecting to host at 10.128.0.26:35589 2020/04/26 18:04:51 checking machine... 2020/04/26 18:04:51 checking revisions... 2020/04/26 18:04:51 testing simple program... syzkaller login: [ 63.992460][ T6893] IPVS: ftp: loaded support on port[0] = 21 2020/04/26 18:04:51 building call list... [ 64.356304][ T398] tipc: TX() has been purged, node left! [ 64.408898][ T398] [ 64.411399][ T398] ============================= [ 64.417574][ T398] WARNING: suspicious RCU usage [ 64.422540][ T398] 5.7.0-rc2-next-20200424-syzkaller #0 Not tainted [ 64.430625][ T398] ----------------------------- [ 64.435566][ T398] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 64.444853][ T398] [ 64.444853][ T398] other info that might help us debug this: [ 64.444853][ T398] [ 64.456295][ T398] [ 64.456295][ T398] rcu_scheduler_active = 2, debug_locks = 1 [ 64.464436][ T398] 4 locks held by kworker/u4:5/398: [ 64.471355][ T398] #0: ffff8880a9772138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 64.482761][ T398] #1: ffffc90002327dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 64.494036][ T398] #2: ffffffff8a5a2c30 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 64.504649][ T398] #3: ffffffff8a5aeba8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 64.516633][ T398] [ 64.516633][ T398] stack backtrace: [ 64.522639][ T398] CPU: 1 PID: 398 Comm: kworker/u4:5 Not tainted 5.7.0-rc2-next-20200424-syzkaller #0 [ 64.532200][ T398] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.542263][ T398] Workqueue: netns cleanup_net [ 64.547017][ T398] Call Trace: [ 64.550307][ T398] dump_stack+0x18f/0x20d [ 64.554659][ T398] ipmr_device_event+0x240/0x2b0 [ 64.559856][ T398] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 64.565786][ T398] notifier_call_chain+0xc0/0x230 [ 64.570909][ T398] call_netdevice_notifiers_info+0xb5/0x130 [ 64.576805][ T398] rollback_registered_many+0x75c/0xe70 [ 64.582383][ T398] ? netif_set_real_num_tx_queues+0x700/0x700 [ 64.588474][ T398] ? lock_downgrade+0x840/0x840 [ 64.593331][ T398] unregister_netdevice_many.part.0+0x16/0x1e0 [ 64.599483][ T398] unregister_netdevice_many+0x36/0x50 [ 64.604939][ T398] ip6gre_exit_batch_net+0x4e8/0x700 [ 64.610229][ T398] ? ip6gre_tunnel_link+0xf0/0xf0 [ 64.615336][ T398] ? rcu_read_lock_held_common+0x130/0x130 [ 64.621246][ T398] ? ip6gre_tunnel_link+0xf0/0xf0 [ 64.626272][ T398] ops_exit_list.isra.0+0x103/0x150 [ 64.631488][ T398] cleanup_net+0x511/0xa50 [ 64.635931][ T398] ? unregister_pernet_device+0x70/0x70 [ 64.641495][ T398] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 64.647488][ T398] ? _raw_spin_unlock_irq+0x1f/0x80 [ 64.652709][ T398] process_one_work+0x965/0x16a0 [ 64.657656][ T398] ? lock_release+0x800/0x800 [ 64.662332][ T398] ? pwq_dec_nr_in_flight+0x310/0x310 [ 64.667799][ T398] ? rwlock_bug.part.0+0x90/0x90 [ 64.672744][ T398] worker_thread+0x96/0xe20 [ 64.677260][ T398] ? process_one_work+0x16a0/0x16a0 [ 64.682457][ T398] kthread+0x38b/0x470 [ 64.686525][ T398] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 64.692245][ T398] ret_from_fork+0x24/0x30 [ 65.865756][ T6881] can: request_module (can-proto-0) failed. executing program [ 67.932356][ T6881] can: request_module (can-proto-0) failed. [ 67.944523][ T6881] can: request_module (can-proto-0) failed.