INFO: task kworker/u4:2:6795 blocked for more than 140 seconds. Not tainted 4.14.117 #8 kobject: 'tx-0' (ffff888025683a58): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'loop4' (ffff8880a4ae01e0): kobject_uevent_env "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kobject: 'loop4' (ffff8880a4ae01e0): fill_kobj_path: path = '/devices/virtual/block/loop4' kworker/u4:2 D26256 6795 2 0x80000000 Workqueue: netns cleanup_net kobject: 'tx-0' (ffff888025683a58): kobject_uevent_env kobject: 'tx-0' (ffff888025683a58): fill_kobj_path: path = '/devices/virtual/net/ip6_vti0/queues/tx-0' Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 kernel/sched/core.c:3383 kobject: 'loop2' (ffff8880a4a1e9a0): kobject_uevent_env schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 kobject: 'loop2' (ffff8880a4a1e9a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'sit0' (ffff88807c85b0f0): kobject_add_internal: parent: 'net', set: 'devices' __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 kobject: 'sit0' (ffff88807c85b0f0): kobject_uevent_env kobject: 'sit0' (ffff88807c85b0f0): fill_kobj_path: path = '/devices/virtual/net/sit0' kobject: 'loop5' (ffff8880a4aea260): kobject_uevent_env kobject: 'loop5' (ffff8880a4aea260): fill_kobj_path: path = '/devices/virtual/block/loop5' mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 kobject: 'queues' (ffff8880366ee848): kobject_add_internal: parent: 'sit0', set: '' kobject: 'loop1' (ffff8880a49d8920): kobject_uevent_env cleanup_net+0x11c/0x880 net/core/net_namespace.c:450 kobject: 'queues' (ffff8880366ee848): kobject_uevent_env kobject: 'loop1' (ffff8880a49d8920): fill_kobj_path: path = '/devices/virtual/block/loop1' kobject: 'queues' (ffff8880366ee848): kobject_uevent_env: filter function caused the event to drop! kobject: 'rx-0' (ffff88804252fa90): kobject_add_internal: parent: 'queues', set: 'queues' process_one_work+0x868/0x1610 kernel/workqueue.c:2114 kobject: 'loop3' (ffff8880a4a8b2a0): kobject_uevent_env kobject: 'rx-0' (ffff88804252fa90): kobject_uevent_env worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x31c/0x430 kernel/kthread.c:232 kobject: 'rx-0' (ffff88804252fa90): fill_kobj_path: path = '/devices/virtual/net/sit0/queues/rx-0' ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 kobject: 'loop3' (ffff8880a4a8b2a0): fill_kobj_path: path = '/devices/virtual/block/loop3' Showing all locks held in the system: kobject: 'tx-0' (ffff888089a38318): kobject_add_internal: parent: 'queues', set: 'queues' 1 lock held by khungtaskd/1008: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4541 2 locks held by getty/6739: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6740: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6741: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6742: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6743: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6744: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6745: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:2/6795: #0: ("%s""netns"){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("%s""netns"){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("%s""netns"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("%s""netns"){+.+.}, at: [] process_one_work+0x76e/0x1610 kernel/workqueue.c:2085 #1: (net_cleanup_work){+.+.}, at: [] process_one_work+0x7ab/0x1610 kernel/workqueue.c:2089 #2: (net_mutex){+.+.}, at: [] cleanup_net+0x11c/0x880 net/core/net_namespace.c:450 1 lock held by syz-executor.1/12366: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12400: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12411: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12436: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12438: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12444: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12454: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12456: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12457: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12458: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12459: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12460: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12462: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12466: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12467: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.1/12470: #0: (net_mutex){+.+.}, at: [] copy_net_ns+0x15a/0x440 net/core/net_namespace.c:410 1 lock held by syz-executor.0/20060: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.3/20058: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.2/20075: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.4/20079: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.5/20087: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 1 lock held by syz-executor.1/20086: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 ============================================= kobject: 'tx-0' (ffff888089a38318): kobject_uevent_env kobject: 'tx-0' (ffff888089a38318): fill_kobj_path: path = '/devices/virtual/net/sit0/queues/tx-0' kobject: 'loop2' (ffff8880a4a1e9a0): kobject_uevent_env kobject: 'ip6tnl0' (ffff88801a4a7470): kobject_add_internal: parent: 'net', set: 'devices' kobject: 'ip6tnl0' (ffff88801a4a7470): kobject_uevent_env kobject: 'ip6tnl0' (ffff88801a4a7470): fill_kobj_path: path = '/devices/virtual/net/ip6tnl0' kobject: 'queues' (ffff8880366eec48): kobject_add_internal: parent: 'ip6tnl0', set: '' kobject: 'queues' (ffff8880366eec48): kobject_uevent_env kobject: 'queues' (ffff8880366eec48): kobject_uevent_env: filter function caused the event to drop! kobject: 'rx-0' (ffff8880812623d0): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'rx-0' (ffff8880812623d0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a1e9a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'rx-0' (ffff8880812623d0): fill_kobj_path: path = '/devices/virtual/net/ip6tnl0/queues/rx-0' kobject: 'loop5' (ffff8880a4aea260): kobject_uevent_env kobject: 'tx-0' (ffff88803b6c2a58): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'loop5' (ffff8880a4aea260): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'tx-0' (ffff88803b6c2a58): kobject_uevent_env kobject: 'tx-0' (ffff88803b6c2a58): fill_kobj_path: path = '/devices/virtual/net/ip6tnl0/queues/tx-0' kobject: 'loop2' (ffff8880a4a1e9a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a1e9a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (ffff8880a4a8b2a0): kobject_uevent_env kobject: 'ip6gre0' (ffff888015b5f2b0): kobject_add_internal: parent: 'net', set: 'devices' kobject: 'loop3' (ffff8880a4a8b2a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'ip6gre0' (ffff888015b5f2b0): kobject_uevent_env kobject: 'ip6gre0' (ffff888015b5f2b0): fill_kobj_path: path = '/devices/virtual/net/ip6gre0' kobject: 'loop5' (ffff8880a4aea260): kobject_uevent_env kobject: 'queues' (ffff888026932048): kobject_add_internal: parent: 'ip6gre0', set: '' kobject: 'loop5' (ffff8880a4aea260): fill_kobj_path: path = '/devices/virtual/block/loop5' kobject: 'queues' (ffff888026932048): kobject_uevent_env kobject: 'queues' (ffff888026932048): kobject_uevent_env: filter function caused the event to drop! kobject: 'loop2' (ffff8880a4a1e9a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a1e9a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (ffff8880a4a8b2a0): kobject_uevent_env kobject: 'rx-0' (ffff888098472490): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'rx-0' (ffff888098472490): kobject_uevent_env kobject: 'loop3' (ffff8880a4a8b2a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'rx-0' (ffff888098472490): fill_kobj_path: path = '/devices/virtual/net/ip6gre0/queues/rx-0' kobject: 'tx-0' (ffff88803f021c98): kobject_add_internal: parent: 'queues', set: 'queues' kobject: 'tx-0' (ffff88803f021c98): kobject_uevent_env kobject: 'tx-0' (ffff88803f021c98): fill_kobj_path: path = '/devices/virtual/net/ip6gre0/queues/tx-0' kobject: 'loop2' (ffff8880a4a1e9a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a1e9a0): fill_kobj_path: path = '/devices/virtual/block/loop2' kobject: 'loop3' (ffff8880a4a8b2a0): kobject_uevent_env kobject: 'loop3' (ffff8880a4a8b2a0): fill_kobj_path: path = '/devices/virtual/block/loop3' kobject: 'loop2' (ffff8880a4a1e9a0): kobject_uevent_env kobject: 'loop2' (ffff8880a4a1e9a0): fill_kobj_path: path = '/devices/virtual/block/loop2' IPVS: ftp: loaded support on port[0] = 21 NMI backtrace for cpu 1 CPU: 1 PID: 1008 Comm: khungtaskd Not tainted 4.14.117 #8 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x19c lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 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:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 20135 Comm: syz-executor.4 Not tainted 4.14.117 #8 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88801d658540 task.stack: ffff888015be0000 RIP: 0010:__lock_acquire+0x692/0x45e0 kernel/locking/lockdep.c:3477 RSP: 0018:ffff888015be74f0 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: 000000000000002a RCX: 1ffff11003acb1c1 RDX: 1ffff11003acb1b6 RSI: ffff88801d658de8 RDI: ffffffff88cc3a40 RBP: ffff888015be76a0 R08: 0000000000000000 R09: ffff88801d658e08 R10: ffff88801d658de8 R11: ffff88801d658540 R12: 0000000000000000 R13: 000000000000002a R14: 0000000000000001 R15: 0dde433673bd63a4 FS: 00007feac6090700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000640000001a CR3: 00000000aa965000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x16f/0x430 kernel/locking/lockdep.c:3991 rcu_lock_acquire include/linux/rcupdate.h:244 [inline] rcu_read_lock include/linux/rcupdate.h:631 [inline] lock_page_memcg+0x39/0x220 mm/memcontrol.c:1650 page_remove_file_rmap mm/rmap.c:1211 [inline] page_remove_rmap+0x19f/0x940 mm/rmap.c:1296 zap_pte_range mm/memory.c:1342 [inline] zap_pmd_range mm/memory.c:1444 [inline] zap_pud_range mm/memory.c:1473 [inline] zap_p4d_range mm/memory.c:1494 [inline] unmap_page_range+0xa2d/0x1770 mm/memory.c:1515 unmap_single_vma+0x15d/0x2c0 mm/memory.c:1560 unmap_vmas+0xac/0x170 mm/memory.c:1590 exit_mmap+0x285/0x4e0 mm/mmap.c:3062 __mmput kernel/fork.c:926 [inline] mmput+0x114/0x440 kernel/fork.c:947 exit_mm kernel/exit.c:545 [inline] do_exit+0x71d/0x2c10 kernel/exit.c:861 do_group_exit+0x111/0x330 kernel/exit.c:977 get_signal+0x348/0x1a80 kernel/signal.c:2407 do_signal+0x86/0x1980 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x15c/0x220 arch/x86/entry/common.c:159 prepare_exit_to_usermode+0x193/0x1f0 arch/x86/entry/common.c:198 retint_user+0x8/0x18 RIP: 0033:0x402170 RSP: 002b:00007feac79b5b38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 000000001fbbffba RDX: 00007feac79b5b40 RSI: 00007feac79b5c70 RDI: 000000000000000b RBP: 00000056ffffff8b R08: 0000000000000005 R09: 0000000000000006 R10: 0000000000000007 R11: 0000000000000008 R12: 000000000000010b R13: 000000000000000c R14: 000000000000000d R15: 00000000ffffffff Code: ff df 48 c1 ea 03 80 3c 02 00 0f 85 f2 2c 00 00 4d 8b bb 70 08 00 00 45 31 e4 45 85 f6 41 0f 94 c4 48 b8 00 00 00 00 00 fc ff df <4c> 89 d2 48 c1 ea 03 80 3c 02 00 0f 85 30 2a 00 00 48 8b 94 24