Buffer I/O error on dev loop7, logical block 3, async page read kworker/dying (5557) used greatest stack depth: 9912 bytes left bond0 (unregistering): Released all slaves INFO: task syz-executor3:2970 blocked for more than 120 seconds. Not tainted 4.16.0-rc6+ #276 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D23424 2970 1404 0x20020004 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 schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:86 [inline] __wait_for_common kernel/sched/completion.c:107 [inline] wait_for_common kernel/sched/completion.c:118 [inline] wait_for_completion+0x415/0x770 kernel/sched/completion.c:139 ucma_destroy_id+0x2f0/0x500 drivers/infiniband/core/ucma.c:611 ucma_write+0x2d6/0x3d0 drivers/infiniband/core/ucma.c:1649 __vfs_write+0xef/0x970 fs/read_write.c:480 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7faac99 RSP: 002b:00000000f77a609c EFLAGS: 00000286 ORIG_RAX: 0000000000000004 RAX: ffffffffffffffda RBX: 0000000000000013 RCX: 0000000020000440 RDX: 0000000000000018 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/800: #0: (rcu_read_lock){....}, at: [<000000000b96be18>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000000b96be18>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000d8641683>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4056: #0: (&f->f_pos_lock){+.+.}, at: [<000000005a1a40de>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/4147: #0: (&tty->ldisc_sem){++++}, at: [<000000002c708764>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002a265953>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4148: #0: (&tty->ldisc_sem){++++}, at: [<000000002c708764>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002a265953>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4149: #0: (&tty->ldisc_sem){++++}, at: [<000000002c708764>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002a265953>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4150: #0: (&tty->ldisc_sem){++++}, at: [<000000002c708764>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002a265953>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4151: #0: (&tty->ldisc_sem){++++}, at: [<000000002c708764>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002a265953>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4152: #0: (&tty->ldisc_sem){++++}, at: [<000000002c708764>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002a265953>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/17448: #0: (&tty->ldisc_sem){++++}, at: [<000000002c708764>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000002a265953>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 5 locks held by kworker/0:9/3010: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000b0de68fa>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000b0de68fa>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000b0de68fa>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<00000000b0de68fa>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)){+.+.}, at: [<00000000e993a6c0>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cgroup_mutex){+.+.}, at: [<0000000084dc1014>] css_killed_work_fn+0x93/0x5c0 kernel/cgroup/cgroup.c:4967 #3: (cpu_hotplug_lock.rw_sem){++++}, at: [<00000000f6047a68>] get_online_cpus include/linux/cpu.h:124 [inline] #3: (cpu_hotplug_lock.rw_sem){++++}, at: [<00000000f6047a68>] memcg_deactivate_kmem_caches+0x21/0xf0 mm/slab_common.c:747 #4: (slab_mutex){+.+.}, at: [<00000000abe45f20>] memcg_deactivate_kmem_caches+0x2f/0xf0 mm/slab_common.c:750 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 800 Comm: khungtaskd Not tainted 4.16.0-rc6+ #276 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 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54