[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 66.152894][ T26] audit: type=1800 audit(1585022339.652:25): pid=9383 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 66.175728][ T26] audit: type=1800 audit(1585022339.662:26): pid=9383 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 66.242342][ T26] audit: type=1800 audit(1585022339.662:27): pid=9383 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.154' (ECDSA) to the list of known hosts. 2020/03/24 03:59:12 fuzzer started 2020/03/24 03:59:13 connecting to host at 10.128.0.26:33557 2020/03/24 03:59:13 checking machine... 2020/03/24 03:59:13 checking revisions... 2020/03/24 03:59:13 testing simple program... syzkaller login: [ 80.683280][ T9549] IPVS: ftp: loaded support on port[0] = 21 2020/03/24 03:59:14 building call list... [ 80.886160][ T188] [ 80.888775][ T188] ============================= [ 80.893621][ T188] WARNING: suspicious RCU usage [ 80.915422][ T188] 5.6.0-rc7-next-20200323-syzkaller #0 Not tainted [ 80.922079][ T188] ----------------------------- [ 80.935239][ T188] net/openvswitch/conntrack.c:1898 RCU-list traversed in non-reader section!! [ 80.944132][ T188] [ 80.944132][ T188] other info that might help us debug this: [ 80.944132][ T188] [ 80.965405][ T188] [ 80.965405][ T188] rcu_scheduler_active = 2, debug_locks = 1 [ 80.974817][ T188] 3 locks held by kworker/u4:4/188: [ 80.980514][ T188] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: process_one_work+0x82a/0x1690 [ 80.990784][ T188] #1: ffffc900013a7dd0 (net_cleanup_work){+.+.}, at: process_one_work+0x85e/0x1690 [ 81.000349][ T188] #2: ffffffff8a55ec88 (pernet_ops_rwsem){++++}, at: cleanup_net+0x9b/0xa50 [ 81.009807][ T188] [ 81.009807][ T188] stack backtrace: [ 81.016322][ T188] CPU: 1 PID: 188 Comm: kworker/u4:4 Not tainted 5.6.0-rc7-next-20200323-syzkaller #0 [ 81.025978][ T188] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 81.036067][ T188] Workqueue: netns cleanup_net [ 81.040833][ T188] Call Trace: [ 81.044128][ T188] dump_stack+0x188/0x20d [ 81.048474][ T188] ovs_ct_exit+0x3db/0x558 [ 81.052894][ T188] ovs_exit_net+0x1df/0xba0 [ 81.057399][ T188] ? ovs_dp_cmd_del+0x270/0x270 [ 81.062244][ T188] ? __mutex_unlock_slowpath+0xe2/0x660 [ 81.067878][ T188] ? ovs_dp_cmd_del+0x270/0x270 [ 81.072725][ T188] ops_exit_list.isra.0+0xa8/0x150 [ 81.077837][ T188] cleanup_net+0x511/0xa50 [ 81.082262][ T188] ? unregister_pernet_device+0x70/0x70 [ 81.087808][ T188] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 81.093804][ T188] process_one_work+0x94b/0x1690 [ 81.098769][ T188] ? pwq_dec_nr_in_flight+0x310/0x310 [ 81.104259][ T188] ? do_raw_spin_lock+0x129/0x2e0 [ 81.109301][ T188] worker_thread+0x96/0xe20 [ 81.113899][ T188] ? process_one_work+0x1690/0x1690 [ 81.119128][ T188] kthread+0x357/0x430 [ 81.123206][ T188] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 81.128930][ T188] ret_from_fork+0x24/0x30 [ 81.305363][ T188] tipc: TX() has been purged, node left! [ 81.347679][ T188] [ 81.350150][ T188] ============================= [ 81.355001][ T188] WARNING: suspicious RCU usage [ 81.360118][ T188] 5.6.0-rc7-next-20200323-syzkaller #0 Not tainted [ 81.366757][ T188] ----------------------------- [ 81.371817][ T188] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 81.380642][ T188] [ 81.380642][ T188] other info that might help us debug this: [ 81.380642][ T188] [ 81.391086][ T188] [ 81.391086][ T188] rcu_scheduler_active = 2, debug_locks = 1 [ 81.399307][ T188] 4 locks held by kworker/u4:4/188: [ 81.404610][ T188] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: process_one_work+0x82a/0x1690 [ 81.414623][ T188] #1: ffffc900013a7dd0 (net_cleanup_work){+.+.}, at: process_one_work+0x85e/0x1690 [ 81.424315][ T188] #2: ffffffff8a55ec88 (pernet_ops_rwsem){++++}, at: cleanup_net+0x9b/0xa50 [ 81.433269][ T188] #3: ffffffff8a56aa00 (rtnl_mutex){+.+.}, at: ip6gre_exit_batch_net+0x88/0x700 [ 81.442556][ T188] [ 81.442556][ T188] stack backtrace: [ 81.448564][ T188] CPU: 0 PID: 188 Comm: kworker/u4:4 Not tainted 5.6.0-rc7-next-20200323-syzkaller #0 [ 81.458103][ T188] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 81.468162][ T188] Workqueue: netns cleanup_net [ 81.472916][ T188] Call Trace: [ 81.476217][ T188] dump_stack+0x188/0x20d [ 81.480559][ T188] ipmr_device_event+0x240/0x2b0 [ 81.485529][ T188] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 81.491425][ T188] notifier_call_chain+0xc0/0x230 [ 81.496453][ T188] call_netdevice_notifiers_info+0xb5/0x130 [ 81.502341][ T188] rollback_registered_many+0x75c/0xe70 [ 81.507901][ T188] ? netif_set_real_num_tx_queues+0x700/0x700 [ 81.514851][ T188] ? lock_downgrade+0x7f0/0x7f0 [ 81.519701][ T188] unregister_netdevice_many.part.0+0x16/0x1e0 [ 81.525865][ T188] unregister_netdevice_many+0x36/0x50 [ 81.531320][ T188] ip6gre_exit_batch_net+0x4e8/0x700 [ 81.536603][ T188] ? ip6gre_tunnel_link+0xf0/0xf0 [ 81.541622][ T188] ? rcu_read_lock_held_common+0x130/0x130 [ 81.547431][ T188] ? ip6gre_tunnel_link+0xf0/0xf0 [ 81.552452][ T188] ops_exit_list.isra.0+0x103/0x150 [ 81.557669][ T188] cleanup_net+0x511/0xa50 [ 81.563054][ T188] ? unregister_pernet_device+0x70/0x70 [ 81.568610][ T188] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 81.574608][ T188] process_one_work+0x94b/0x1690 [ 81.579575][ T188] ? pwq_dec_nr_in_flight+0x310/0x310 [ 81.585315][ T188] ? do_raw_spin_lock+0x129/0x2e0 [ 81.590383][ T188] worker_thread+0x96/0xe20 [ 81.594898][ T188] ? process_one_work+0x1690/0x1690 [ 81.600095][ T188] kthread+0x357/0x430 [ 81.604197][ T188] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 81.609917][ T188] ret_from_fork+0x24/0x30 [ 82.279904][ T9537] can: request_module (can-proto-0) failed. executing program [ 84.774683][ T9537] can: request_module (can-proto-0) failed. [ 84.787329][ T9537] can: request_module (can-proto-0) failed.