INFO: task kworker/u4:5:7783 blocked for more than 140 seconds. Not tainted 5.0.0-rc7+ #82 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:5 D25776 7783 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3485 schedule+0x92/0x180 kernel/sched/core.c:3529 exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline] _synchronize_rcu_expedited.constprop.0+0x4d4/0x530 kernel/rcu/tree_exp.h:622 synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:762 synchronize_net+0x3b/0x60 net/core/dev.c:9247 rollback_registered_many+0x67b/0xfd0 net/core/dev.c:8171 unregister_netdevice_many.part.0+0x1b/0x1f0 net/core/dev.c:9292 unregister_netdevice_many+0x3b/0x50 net/core/dev.c:9291 ip6gre_exit_batch_net+0x535/0x750 net/ipv6/ip6_gre.c:1602 ops_exit_list.isra.0+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:551 process_one_work+0x98e/0x1790 kernel/workqueue.c:2173 worker_thread+0x98/0xe40 kernel/workqueue.c:2319 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.4:26613 blocked for more than 140 seconds. Not tainted 5.0.0-rc7+ #82 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28192 26613 13167 0x80000004 Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3485 schedule+0x92/0x180 kernel/sched/core.c:3529 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3587 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 cangw_pernet_exit+0x13/0x30 net/can/gw.c:1029 ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153 setup_net+0x3f2/0x730 net/core/net_namespace.c:331 copy_net_ns+0x1d9/0x340 net/core/net_namespace.c:437 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2550 __do_sys_unshare kernel/fork.c:2618 [inline] __se_sys_unshare kernel/fork.c:2616 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2616 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: 24 28 48 89 4c 24 08 66 c7 44 24 10 01 01 48 c7 44 24 18 00 00 00 00 e8 a5 b0 fc ff 48 8b 44 24 38 48 89 04 24 e8 d7 77 fb ff <48> 8b 6c 24 40 48 83 c4 48 c3 48 89 d1 eb 90 e8 73 20 00 00 e9 7e RSP: 002b:00007f594bafac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457e29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f594bafb6d4 R13: 00000000004c6c3b R14: 00000000004dc3f8 R15: 00000000ffffffff INFO: task syz-executor.4:26626 blocked for more than 140 seconds. Not tainted 5.0.0-rc7+ #82 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28192 26626 13167 0x80000004 Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3485 schedule+0x92/0x180 kernel/sched/core.c:3529 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3587 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 cangw_pernet_exit+0x13/0x30 net/can/gw.c:1029 ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:153 setup_net+0x3f2/0x730 net/core/net_namespace.c:331 copy_net_ns+0x1d9/0x340 net/core/net_namespace.c:437 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2550 __do_sys_unshare kernel/fork.c:2618 [inline] __se_sys_unshare kernel/fork.c:2616 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2616 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e29 Code: 24 28 48 89 4c 24 08 66 c7 44 24 10 01 01 48 c7 44 24 18 00 00 00 00 e8 a5 b0 fc ff 48 8b 44 24 38 48 89 04 24 e8 d7 77 fb ff <48> 8b 6c 24 40 48 83 c4 48 c3 48 89 d1 eb 90 e8 73 20 00 00 e9 7e RSP: 002b:00007f594ba97c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457e29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000 RBP: 000000000073c180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f594ba986d4 R13: 00000000004c6c3b R14: 00000000004dc3f8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1040: #0: 0000000086dd80b6 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4389 1 lock held by rsyslogd/7553: 2 locks held by getty/7642: #0: 00000000824e0cf8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006d6e3a8b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7643: #0: 0000000093b37aad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000d071407 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7644: #0: 00000000f301dd8a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000fcacc572 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7645: #0: 0000000030ec59b9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000edd5236b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7646: #0: 0000000054299a3e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ba661e62 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7647: #0: 000000000c7f8541 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f38e3d19 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7648: #0: 0000000030e117f6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000862e7b29 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 3 locks held by kworker/1:4/7689: #0: 000000003396e8ff ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000003396e8ff ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000003396e8ff ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000003396e8ff ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000003396e8ff ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000003396e8ff ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000003396e8ff ((wq_completion)"events"){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2144 #1: 000000005fa4a057 (deferred_process_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2148 #2: 000000008e215576 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 4 locks held by kworker/u4:5/7783: #0: 00000000fa065362 ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000fa065362 ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000fa065362 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000fa065362 ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000fa065362 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000fa065362 ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000fa065362 ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2144 #1: 00000000dd39d462 (net_cleanup_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2148 #2: 00000000b9d8a8ea (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0x960 net/core/net_namespace.c:518 #3: 000000008e215576 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 3 locks held by kworker/u4:7/8386: #0: 00000000a233c76c (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9934 [inline] #0: 00000000a233c76c (&rq->lock){-.-.}, at: pick_next_task_fair+0x10f3/0x1860 kernel/sched/fair.c:7017 #1: 0000000086dd80b6 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6014 #2: 0000000054d39de9 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:937 3 locks held by kworker/0:5/12888: #0: 000000006f0c8c92 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 000000006f0c8c92 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000006f0c8c92 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000006f0c8c92 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000006f0c8c92 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000006f0c8c92 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000006f0c8c92 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2144 #1: 0000000004fa2fb3 ((addr_chk_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2148 #2: 000000008e215576 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 2 locks held by syz-executor.4/26613: #0: 00000000b9d8a8ea (pernet_ops_rwsem){++++}, at: copy_net_ns+0x1ba/0x340 net/core/net_namespace.c:433 #1: 000000008e215576 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 2 locks held by syz-executor.4/26626: #0: 00000000b9d8a8ea (pernet_ops_rwsem){++++}, at: copy_net_ns+0x1ba/0x340 net/core/net_namespace.c:433 #1: 000000008e215576 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1040 Comm: khungtaskd Not tainted 5.0.0-rc7+ #82 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8386 Comm: kworker/u4:7 Not tainted 5.0.0-rc7+ #82 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:debug_lockdep_rcu_enabled.part.0+0x2a/0x60 kernel/rcu/update.c:249 Code: 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 65 48 8b 1c 25 40 ee 01 00 48 8d bb 7c 08 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 10 8b 93 7c 08 00 RSP: 0018:ffff8880609a7cb0 EFLAGS: 00000a03 RAX: dffffc0000000000 RBX: ffff8880618fc700 RCX: 1ffffffff12b9f2f RDX: 0000000000000000 RSI: ffff8880618fcfd0 RDI: ffff8880618fcf7c RBP: ffff8880609a7cb8 R08: 0000000000000002 R09: ffff8880618fcff0 R10: ffff8880618fcfd0 R11: 0000000000000001 R12: 0000000000000001 R13: 000000000000027e R14: ffff8880972f2a30 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000092f99000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_lockdep_rcu_enabled+0x71/0xa0 kernel/rcu/update.c:248 rcu_read_lock include/linux/rcupdate.h:608 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:419 [inline] batadv_nc_worker+0x11c/0x760 net/batman-adv/network-coding.c:730 process_one_work+0x98e/0x1790 kernel/workqueue.c:2173 worker_thread+0x98/0xe40 kernel/workqueue.c:2319 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352