INFO: task kworker/1:0:28676 blocked for more than 140 seconds. Not tainted 4.14.232-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:0 D28568 28676 2 0x80000000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 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 hub_port_init+0xfdc/0x2970 drivers/usb/core/hub.c:4555 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/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/7680: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 2 locks held by agetty/7715: #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/1:0/28676: #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 1 lock held by syz-executor.0/21413: #0: (&mm->mmap_sem){++++}, at: [] __do_page_fault+0x7b8/0xad0 arch/x86/mm/fault.c:1378 2 locks held by syz-executor.5/21510: #0: (br_ioctl_mutex){+.+.}, at: [] sock_ioctl+0x239/0x4c0 net/socket.c:1036 #1: (rcu_preempt_state.barrier_mutex){+.+.}, at: [] _rcu_barrier+0x56/0x3b0 kernel/rcu/tree.c:3546 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.232-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4607 Comm: systemd-journal Not tainted 4.14.232-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a22a6400 task.stack: ffff8880a22a8000 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x41/0xe0 kernel/locking/spinlock.c:192 RSP: 0018:ffff8880a22afaf0 EFLAGS: 00000046 RAX: 1ffffffff11e1259 RBX: 0000000000000086 RCX: 1ffff11014454d91 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff8c037948 RBP: ffffffff8c037948 R08: 1ffff110043185c3 R09: 0000000000000000 R10: 0000000000000000 R11: ffff8880a22a6400 R12: ffff8881ebb1c4c0 R13: 0000000000000007 R14: ffffffff8c037948 R15: ffff8880218c2e00 FS: 00007f81cd45c8c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f81caa52000 CR3: 00000000a2388000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __debug_check_no_obj_freed lib/debugobjects.c:760 [inline] debug_check_no_obj_freed+0x2c0/0x680 lib/debugobjects.c:776 kmem_cache_free+0x156/0x2b0 mm/slab.c:3757 putname+0xcd/0x110 fs/namei.c:259 filename_parentat+0x477/0x520 fs/namei.c:2430 filename_create+0x8a/0x3f0 fs/namei.c:3657 user_path_create fs/namei.c:3732 [inline] SYSC_mkdirat fs/namei.c:3864 [inline] SyS_mkdirat+0x95/0x270 fs/namei.c:3856 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f81cc717687 RSP: 002b:00007ffc97dd4848 EFLAGS: 00000293 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007ffc97dd78b0 RCX: 00007f81cc717687 RDX: 0000000000000000 RSI: 00000000000001ed RDI: 000055fc01bb58a0 RBP: 00007ffc97dd4880 R08: 000055fc0103e3e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 000055fc01bb58a0 R15: 00007ffc97dd4ec0 Code: e8 25 f4 1e fa 48 89 ef e8 ad 7d 1f fa f6 c7 02 75 4c 48 c7 c0 c8 92 f0 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 <75> 72 48 83 3d 8d d0 cd 01 00 74 64 48 89 df 57 9d 0f 1f 44 00