INFO: task kworker/0:3:5865 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #278 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:3 D22432 5865 2 0x80000000 Workqueue: events cgwb_release_workfn Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 bit_wait+0x18/0x90 kernel/sched/wait_bit.c:250 __wait_on_bit+0x88/0x130 kernel/sched/wait_bit.c:51 out_of_line_wait_on_bit+0x204/0x3a0 kernel/sched/wait_bit.c:64 wait_on_bit include/linux/wait_bit.h:84 [inline] wb_shutdown+0x335/0x430 mm/backing-dev.c:377 cgwb_release_workfn+0x8b/0x61d mm/backing-dev.c:520 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Showing all locks held in the system: 2 locks held by kworker/0:1/24: #0: ((wq_completion)"events"){+.+.}, at: [<000000000d2c8809>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"events"){+.+.}, at: [<000000000d2c8809>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"events"){+.+.}, at: [<000000000d2c8809>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"events"){+.+.}, at: [<000000000d2c8809>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&wb->release_work)){+.+.}, at: [<00000000a34067a2>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 2 locks held by khungtaskd/870: #0: (rcu_read_lock){....}, at: [<000000008904931c>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000008904931c>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000d9ace1f1>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4394: #0: (&tty->ldisc_sem){++++}, at: [<00000000e3a8a7c3>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000045b8c820>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4395: #0: (&tty->ldisc_sem){++++}, at: [<00000000e3a8a7c3>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000045b8c820>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4396: #0: (&tty->ldisc_sem){++++}, at: [<00000000e3a8a7c3>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000045b8c820>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4397: #0: (&tty->ldisc_sem){++++}, at: [<00000000e3a8a7c3>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000045b8c820>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4398: #0: (&tty->ldisc_sem){++++}, at: [<00000000e3a8a7c3>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000045b8c820>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4399: #0: (&tty->ldisc_sem){++++}, at: [<00000000e3a8a7c3>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000045b8c820>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 4 locks held by syz-executor3/4470: #0: (sb_writers#10){.+.+}, at: [<00000000306e9c5d>] sb_start_write include/linux/fs.h:1548 [inline] #0: (sb_writers#10){.+.+}, at: [<00000000306e9c5d>] mnt_want_write+0x3f/0xb0 fs/namespace.c:386 #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000005d154aa5>] inode_lock_nested include/linux/fs.h:748 [inline] #1: (&type->i_mutex_dir_key#3/1){+.+.}, at: [<000000005d154aa5>] do_rmdir+0x380/0x5f0 fs/namei.c:3907 #2: (&type->i_mutex_dir_key#3){++++}, at: [<0000000039a17fd3>] inode_lock include/linux/fs.h:713 [inline] #2: (&type->i_mutex_dir_key#3){++++}, at: [<0000000039a17fd3>] vfs_rmdir+0xd6/0x410 fs/namei.c:3848 #3: (cgroup_mutex){+.+.}, at: [<000000005805d84a>] cgroup_kn_lock_live+0x29e/0x580 kernel/cgroup/cgroup.c:1535 2 locks held by kworker/0:3/5865: #0: ((wq_completion)"events"){+.+.}, at: [<000000000d2c8809>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"events"){+.+.}, at: [<000000000d2c8809>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"events"){+.+.}, at: [<000000000d2c8809>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"events"){+.+.}, at: [<000000000d2c8809>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&wb->release_work)){+.+.}, at: [<00000000a34067a2>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 2 locks held by getty/24186: #0: (&tty->ldisc_sem){++++}, at: [<00000000e3a8a7c3>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000045b8c820>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 1 lock held by syz-executor4/27990: #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by syz-executor0/27991: #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by syz-executor1/27992: #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by syz-executor5/27993: #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by syz-executor7/27994: #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 1 lock held by syz-executor6/27995: #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] inode_lock_shared include/linux/fs.h:723 [inline] #0: (&type->i_mutex_dir_key#3){++++}, at: [<00000000c7a76ca0>] lookup_slow+0x18e/0x4d0 fs/namei.c:1612 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 870 Comm: khungtaskd Not tainted 4.16.0-rc7+ #278 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+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 20679 Comm: kworker/0:8 Not tainted 4.16.0-rc7+ #278 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: cgroup_destroy css_killed_work_fn RIP: 0010:__wrmsr arch/x86/include/asm/msr.h:105 [inline] RIP: 0010:native_write_msr+0xa/0x30 arch/x86/include/asm/msr.h:148 RSP: 0018:ffff88018a926e40 EFLAGS: 00000282 RAX: 00000000000000fb RBX: ffff8801db318144 RCX: 0000000000000830 RDX: 0000000000000001 RSI: 00000000000000fb RDI: 0000000000000830 RBP: ffff88018a926e40 R08: 1ffff10031524e1b R09: 0000000000000000 R10: ffff88018a927120 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000001 R15: ffffffff81a9d610 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000080ed1bc CR3: 0000000007a22006 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: paravirt_write_msr arch/x86/include/asm/paravirt.h:117 [inline] wrmsrl arch/x86/include/asm/paravirt.h:150 [inline] native_x2apic_icr_write arch/x86/include/asm/apic.h:241 [inline] __x2apic_send_IPI_dest+0x5c/0x80 arch/x86/kernel/apic/x2apic_phys.c:117 x2apic_send_IPI+0x6f/0xa0 arch/x86/kernel/apic/x2apic_cluster.c:35 native_send_call_func_single_ipi+0x55/0x70 arch/x86/kernel/smp.c:136 arch_send_call_function_single_ipi arch/x86/include/asm/smp.h:121 [inline] generic_exec_single+0x185/0x5b0 kernel/smp.c:179 smp_call_function_single+0x2d2/0x560 kernel/smp.c:299 smp_call_function_many+0x773/0x930 kernel/smp.c:434 smp_call_function kernel/smp.c:492 [inline] on_each_cpu+0x3d/0x1b0 kernel/smp.c:602 drain_cpu_caches mm/slab.c:2238 [inline] __kmem_cache_shrink+0x32/0x160 mm/slab.c:2299 __kmemcg_cache_deactivate+0x9/0x10 mm/slab.c:2314 memcg_deactivate_kmem_caches+0x68/0xf0 mm/slab_common.c:758 memcg_offline_kmem.part.56+0x58/0x340 mm/memcontrol.c:2817 memcg_offline_kmem mm/memcontrol.c:4276 [inline] mem_cgroup_css_offline+0x343/0x510 mm/memcontrol.c:4272 offline_css kernel/cgroup/cgroup.c:4702 [inline] css_killed_work_fn+0x121/0x5c0 kernel/cgroup/cgroup.c:4970 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Code: 5d c3 0f 21 d0 5d c3 0f 21 d8 5d c3 0f 21 f0 5d c3 0f 0b 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 55 89 f9 89 f0 48 89 e5 0f 30 <0f> 1f 44 00 00 5d c3 48 89 d6 89 c2 48 c1 e6 20 48 09 d6 31 d2