============================= WARNING: suspicious RCU usage 5.6.0-rc7-next-20200324-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/u4:4/125: #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: process_one_work+0x82a/0x1690 kernel/workqueue.c:2237 #1: ffffc900013a7dd0 (net_cleanup_work){+.+.}, at: process_one_work+0x85e/0x1690 kernel/workqueue.c:2241 #2: ffffffff8a55f388 (pernet_ops_rwsem){++++}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:551 stack backtrace: CPU: 0 PID: 125 Comm: kworker/u4:4 Not tainted 5.6.0-rc7-next-20200324-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+0x94b/0x1690 kernel/workqueue.c:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 kthread+0x357/0x430 kernel/kthread.c:255 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-20200324-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/u4:4/125: #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:250 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff88821b78d928 ((wq_completion)netns){+.+.}, at: process_one_work+0x82a/0x1690 kernel/workqueue.c:2237 #1: ffffc900013a7dd0 (net_cleanup_work){+.+.}, at: process_one_work+0x85e/0x1690 kernel/workqueue.c:2241 #2: ffffffff8a55f388 (pernet_ops_rwsem){++++}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:551 #3: ffffffff8a56b100 (rtnl_mutex){+.+.}, at: ip6gre_exit_batch_net+0x88/0x700 net/ipv6/ip6_gre.c:1602 stack backtrace: CPU: 1 PID: 125 Comm: kworker/u4:4 Not tainted 5.6.0-rc7-next-20200324-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+0x94b/0x1690 kernel/workqueue.c:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 kthread+0x357/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352