WARNING: suspicious RCU usage in ovs_ct_exit ============================= WARNING: suspicious RCU usage 5.6.0-rc7-next-20200327-syzkaller #0 Not tainted ----------------------------- net/openvswitch/conntrack.c:1898 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 3 locks held by kworker/u4:2/36: #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2237 #1: ffffc90000e97dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2241 #2: ffffffff8a569bb0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:551 stack backtrace: CPU: 1 PID: 36 Comm: kworker/u4:2 Not tainted 5.6.0-rc7-next-20200327-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 ovs_ct_limit_exit net/openvswitch/conntrack.c:1898 [inline] ovs_ct_exit+0x3db/0x558 net/openvswitch/conntrack.c:2295 ovs_exit_net+0x1df/0xba0 net/openvswitch/datapath.c:2469 ops_exit_list.isra.0+0xa8/0x150 net/core/net_namespace.c:172 cleanup_net+0x511/0xa50 net/core/net_namespace.c:589 process_one_work+0x965/0x16a0 kernel/workqueue.c:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 tipc: TX() has been purged, node left! ============================= WARNING: suspicious RCU usage 5.6.0-rc7-next-20200327-syzkaller #0 Not tainted ----------------------------- net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 4 locks held by kworker/u4:2/36: #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2237 #1: ffffc90000e97dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2241 #2: ffffffff8a569bb0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:551 #3: ffffffff8a575aa8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 net/ipv6/ip6_gre.c:1602 stack backtrace: CPU: 0 PID: 36 Comm: kworker/u4:2 Not tainted 5.6.0-rc7-next-20200327-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 ipmr_device_event+0x240/0x2b0 net/ipv4/ipmr.c:1757 notifier_call_chain+0xc0/0x230 kernel/notifier.c:83 call_netdevice_notifiers_info net/core/dev.c:1948 [inline] call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1933 call_netdevice_notifiers_extack net/core/dev.c:1960 [inline] call_netdevice_notifiers net/core/dev.c:1974 [inline] rollback_registered_many+0x75c/0xe70 net/core/dev.c:8810 unregister_netdevice_many.part.0+0x16/0x1e0 net/core/dev.c:9970 unregister_netdevice_many+0x36/0x50 net/core/dev.c:9969 ip6gre_exit_batch_net+0x4e8/0x700 net/ipv6/ip6_gre.c:1605 ops_exit_list.isra.0+0x103/0x150 net/core/net_namespace.c:175 cleanup_net+0x511/0xa50 net/core/net_namespace.c:589 process_one_work+0x965/0x16a0 kernel/workqueue.c:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 [ 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. Starting Load/Save RF Kill Switch Status... Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.74' (ECDSA) to the list of known hosts. 2020/03/28 12:06:50 fuzzer started 2020/03/28 12:06:52 connecting to host at 10.128.0.26:39281 2020/03/28 12:06:52 checking machine... 2020/03/28 12:06:52 checking revisions... 2020/03/28 12:06:52 testing simple program... syzkaller login: [ 59.362381][ T7055] IPVS: ftp: loaded support on port[0] = 21 2020/03/28 12:06:52 building call list... [ 59.574512][ T36] [ 59.577041][ T36] ============================= [ 59.586692][ T36] WARNING: suspicious RCU usage [ 59.598574][ T36] 5.6.0-rc7-next-20200327-syzkaller #0 Not tainted [ 59.624093][ T36] ----------------------------- [ 59.629017][ T36] net/openvswitch/conntrack.c:1898 RCU-list traversed in non-reader section!! [ 59.638866][ T36] [ 59.638866][ T36] other info that might help us debug this: [ 59.638866][ T36] [ 59.649656][ T36] [ 59.649656][ T36] rcu_scheduler_active = 2, debug_locks = 1 [ 59.684178][ T36] 3 locks held by kworker/u4:2/36: [ 59.689384][ T36] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 59.700925][ T36] #1: ffffc90000e97dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 59.711571][ T36] #2: ffffffff8a569bb0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 59.721581][ T36] [ 59.721581][ T36] stack backtrace: [ 59.729032][ T36] CPU: 1 PID: 36 Comm: kworker/u4:2 Not tainted 5.6.0-rc7-next-20200327-syzkaller #0 [ 59.738495][ T36] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.748568][ T36] Workqueue: netns cleanup_net [ 59.753332][ T36] Call Trace: [ 59.756630][ T36] dump_stack+0x188/0x20d [ 59.760965][ T36] ovs_ct_exit+0x3db/0x558 [ 59.765392][ T36] ovs_exit_net+0x1df/0xba0 [ 59.769904][ T36] ? synchronize_rcu.part.0+0xda/0xf0 [ 59.775293][ T36] ? synchronize_rcu_expedited+0x620/0x620 [ 59.781098][ T36] ? ovs_dp_cmd_del+0x270/0x270 [ 59.785953][ T36] ? ovs_dp_cmd_del+0x270/0x270 [ 59.790803][ T36] ops_exit_list.isra.0+0xa8/0x150 [ 59.795933][ T36] cleanup_net+0x511/0xa50 [ 59.800365][ T36] ? unregister_pernet_device+0x70/0x70 [ 59.805916][ T36] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 59.811895][ T36] ? _raw_spin_unlock_irq+0x1f/0x80 [ 59.817188][ T36] process_one_work+0x965/0x16a0 [ 59.822140][ T36] ? lock_release+0x800/0x800 [ 59.826819][ T36] ? pwq_dec_nr_in_flight+0x310/0x310 [ 59.832202][ T36] ? rwlock_bug.part.0+0x90/0x90 [ 59.837153][ T36] worker_thread+0x96/0xe20 [ 59.841672][ T36] ? process_one_work+0x16a0/0x16a0 [ 59.846870][ T36] kthread+0x388/0x470 [ 59.850938][ T36] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 59.857090][ T36] ret_from_fork+0x24/0x30 [ 60.103613][ T36] tipc: TX() has been purged, node left! [ 60.156323][ T36] [ 60.158793][ T36] ============================= [ 60.169832][ T36] WARNING: suspicious RCU usage [ 60.174814][ T36] 5.6.0-rc7-next-20200327-syzkaller #0 Not tainted [ 60.193072][ T36] ----------------------------- [ 60.213581][ T36] net/ipv4/ipmr.c:1757 RCU-list traversed in non-reader section!! [ 60.221570][ T36] [ 60.221570][ T36] other info that might help us debug this: [ 60.221570][ T36] [ 60.233076][ T36] [ 60.233076][ T36] rcu_scheduler_active = 2, debug_locks = 1 [ 60.241916][ T36] 4 locks held by kworker/u4:2/36: [ 60.247713][ T36] #0: ffff8880a977e138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 [ 60.259305][ T36] #1: ffffc90000e97dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 [ 60.269946][ T36] #2: ffffffff8a569bb0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 [ 60.279759][ T36] #3: ffffffff8a575aa8 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0x88/0x700 [ 60.289717][ T36] [ 60.289717][ T36] stack backtrace: [ 60.295965][ T36] CPU: 0 PID: 36 Comm: kworker/u4:2 Not tainted 5.6.0-rc7-next-20200327-syzkaller #0 [ 60.305547][ T36] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.315619][ T36] Workqueue: netns cleanup_net [ 60.320388][ T36] Call Trace: [ 60.323680][ T36] dump_stack+0x188/0x20d [ 60.328020][ T36] ipmr_device_event+0x240/0x2b0 [ 60.332959][ T36] ? __sanitizer_cov_trace_switch+0x45/0x70 [ 60.338861][ T36] notifier_call_chain+0xc0/0x230 [ 60.343898][ T36] call_netdevice_notifiers_info+0xb5/0x130 [ 60.349791][ T36] rollback_registered_many+0x75c/0xe70 [ 60.355345][ T36] ? netif_set_real_num_tx_queues+0x700/0x700 [ 60.361427][ T36] ? lock_downgrade+0x840/0x840 [ 60.366292][ T36] unregister_netdevice_many.part.0+0x16/0x1e0 [ 60.372462][ T36] unregister_netdevice_many+0x36/0x50 [ 60.377928][ T36] ip6gre_exit_batch_net+0x4e8/0x700 [ 60.383222][ T36] ? ip6gre_tunnel_link+0xf0/0xf0 [ 60.388256][ T36] ? rcu_read_lock_held_common+0x130/0x130 [ 60.394067][ T36] ? ip6gre_tunnel_link+0xf0/0xf0 [ 60.399108][ T36] ops_exit_list.isra.0+0x103/0x150 [ 60.404326][ T36] cleanup_net+0x511/0xa50 [ 60.408758][ T36] ? unregister_pernet_device+0x70/0x70 [ 60.414310][ T36] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 60.420291][ T36] ? _raw_spin_unlock_irq+0x1f/0x80 [ 60.425495][ T36] process_one_work+0x965/0x16a0 [ 60.430442][ T36] ? lock_release+0x800/0x800 [ 60.435133][ T36] ? pwq_dec_nr_in_flight+0x310/0x310 [ 60.440519][ T36] ? rwlock_bug.part.0+0x90/0x90 [ 60.445484][ T36] worker_thread+0x96/0xe20 [ 60.450005][ T36] ? process_one_work+0x16a0/0x16a0 [ 60.455205][ T36] kthread+0x388/0x470 [ 60.459271][ T36] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 60.465002][ T36] ret_from_fork+0x24/0x30 [ 61.331273][ T7041] can: request_module (can-proto-0) failed. executing program [ 63.529363][ T7041] can: request_module (can-proto-0) failed. [ 63.542044][ T7041] can: request_module (can-proto-0) failed.