INFO: task kworker/1:5:9196 blocked for more than 140 seconds. Not tainted 4.14.225-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:5 D26440 9196 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: EXT4-fs (sda1): Delayed block allocation failed for inode 18566 at logical offset 0 with max blocks 17 with error 28 context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 EXT4-fs (sda1): This should not happen!! Data will be lost schedule+0x8d/0x1b0 kernel/sched/core.c:3428 usb_kill_urb.part.0+0x125/0x190 drivers/usb/core/urb.c:691 usb_kill_urb+0x7c/0x90 drivers/usb/core/urb.c:686 usb_start_wait_urb+0x209/0x440 drivers/usb/core/message.c:62 usb_internal_control_msg drivers/usb/core/message.c:100 [inline] usb_control_msg+0x302/0x450 drivers/usb/core/message.c:151 usb_get_descriptor+0xc0/0x160 drivers/usb/core/message.c:652 usb_get_device_descriptor+0x71/0xd0 drivers/usb/core/message.c:924 hub_port_init+0x629/0x2970 drivers/usb/core/hub.c:4647 hub_port_connect drivers/usb/core/hub.c:4905 [inline] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] port_event drivers/usb/core/hub.c:5194 [inline] hub_event+0x18fd/0x3d70 drivers/usb/core/hub.c:5274 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Showing all locks held in the system: 1 lock held by khungtaskd/1529: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by agetty/7905: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156 2 locks held by agetty/7906: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e3/0x1680 drivers/tty/n_tty.c:2156 5 locks held by kworker/1:5/9196: #0: ("usb_hub_wq"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&hub->events)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (&dev->mutex){....}, at: [] device_lock include/linux/device.h:1081 [inline] #2: (&dev->mutex){....}, at: [] hub_event+0x108/0x3d70 drivers/usb/core/hub.c:5220 #3: (&port_dev->status_lock){+.+.}, at: [] usb_lock_port drivers/usb/core/hub.c:2934 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect drivers/usb/core/hub.c:4904 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_port_connect_change drivers/usb/core/hub.c:5088 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] port_event drivers/usb/core/hub.c:5194 [inline] #3: (&port_dev->status_lock){+.+.}, at: [] hub_event+0x18e8/0x3d70 drivers/usb/core/hub.c:5274 #4: (hcd->address0_mutex){+.+.}, at: [] hub_port_init+0x15b/0x2970 drivers/usb/core/hub.c:4429 3 locks held by kworker/u4:0/30905: #0: ("events_unbound"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&sub_info->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 #2: (&cgroup_threadgroup_rwsem){++++}, at: [] copy_process kernel/fork.c:1605 [inline] #2: (&cgroup_threadgroup_rwsem){++++}, at: [] _do_fork+0x184/0xc80 kernel/fork.c:2091 1 lock held by systemd-udevd/6169: #0: (&cgroup_threadgroup_rwsem){++++}, at: [] do_exit+0x22b/0x2850 kernel/exit.c:824 1 lock held by systemd-udevd/6180: #0: (&cgroup_threadgroup_rwsem){++++}, at: [] do_exit+0x22b/0x2850 kernel/exit.c:824 1 lock held by systemd-udevd/6191: #0: (&cgroup_threadgroup_rwsem){++++}, at: [] do_exit+0x22b/0x2850 kernel/exit.c:824 1 lock held by syz-executor.4/6227: #0: (rcu_preempt_state.barrier_mutex){+.+.}, at: [] _rcu_barrier+0x56/0x3b0 kernel/rcu/tree.c:3546 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1529 Comm: khungtaskd Not tainted 4.14.225-syzkaller #0 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+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 30905 Comm: kworker/u4:0 Not tainted 4.14.225-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker task: ffff888098ad24c0 task.stack: ffff88808d688000 RIP: 0010:switch_fpu_prepare arch/x86/include/asm/fpu/internal.h:534 [inline] RIP: 0010:__switch_to+0x8d/0xf60 arch/x86/kernel/process_64.c:417 RSP: 0018:ffff8880b541fb30 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff8880ba52a318 RCX: 1ffff1101315a5b3 RDX: 0000000000000004 RSI: ffffffff87ccd680 RDI: ffff888098ad3944 RBP: ffff8880b5414200 R08: ffff888098ad2898 R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888098ad24c0 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff888098ad3880 FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcfb8a6000 CR3: 00000000a3a3f000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: Code: 13 00 00 48 89 44 24 08 e8 91 6e fd 01 49 8d bc 24 84 14 00 00 89 44 24 04 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 42 0f b6 04 28 <38> d0 7f 08 84 c0 0f 85 13 0c 00 00 41 80 bc 24 84 14 00 00 00