INFO: task kworker/0:3:8867 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/0:3 D26720 8867 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 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/1531: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 5 locks held by kworker/0:3/8867: #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 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1531 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: 4622 Comm: systemd-journal Not tainted 4.14.225-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a10a60c0 task.stack: ffff8880a10a8000 RIP: 0010:deref_stack_reg+0x1b/0x1a0 arch/x86/kernel/unwind_orc.c:285 RSP: 0018:ffff8880a10af710 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff11014215eef RCX: ffffffff8a8a36a6 RDX: ffff8880a10af848 RSI: ffff8880a10afb88 RDI: ffff8880a10af800 RBP: ffff8880a10afb88 R08: ffffffff8a8a36aa R09: ffffffff8a8a36ab R10: 000000000005f6fb R11: 0000000000000001 R12: ffff8880a10af800 R13: ffff8880a10af848 R14: ffff8880a10af850 R15: ffff8880a10af800 FS: 00007f28d90838c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f28d5e1c028 CR3: 00000000a1024000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xc98/0x17d0 arch/x86/kernel/unwind_orc.c:425 __save_stack_trace+0x90/0x160 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc mm/slab.c:3390 [inline] kmem_cache_alloc_trace+0x11b/0x3d0 mm/slab.c:3616 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] aa_alloc_file_ctx security/apparmor/include/file.h:60 [inline] apparmor_file_alloc_security+0x129/0x800 security/apparmor/lsm.c:431 security_file_alloc+0x66/0xa0 security/security.c:874 get_empty_filp+0x15c/0x3e0 fs/file_table.c:129 path_openat+0x84/0x2970 fs/namei.c:3545 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f28d8613840 RSP: 002b:00007ffd757d0488 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffd757d0790 RCX: 00007f28d8613840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005630041334b0 RBP: 000000000000000d R08: 00000000000001c0 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000563004126040 R14: 00007ffd757d0750 R15: 00005630041339d0 Code: 48 8b 07 48 89 06 c3 66 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 41 56 41 55 49 89 d5 41 54 49 89 fc 55 48 89 f5 53 <48> 83 ec 48 48 c7 44 24 08 b3 8a b5 41 48 8d 5c 24 08 48 c7 44