INFO: task kworker/1:2:4625 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/1:2 D26672 4625 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 Process accounting resumed Process accounting resumed 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 5 locks held by kworker/1:2/4625: #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 syz-executor.3/27673: #0: (&acct->lock#2){+.+.}, at: [] acct_get kernel/acct.c:161 [inline] #0: (&acct->lock#2){+.+.}, at: [] slow_acct_process kernel/acct.c:577 [inline] #0: (&acct->lock#2){+.+.}, at: [] acct_process+0x1b5/0x470 kernel/acct.c:605 #1: (sb_writers#3){.+.+}, at: [] file_start_write_trylock include/linux/fs.h:2719 [inline] #1: (sb_writers#3){.+.+}, at: [] do_acct_process+0xc9d/0xfe0 kernel/acct.c:517 #2: (&sb->s_type->i_mutex_key#10){++++}, at: [] inode_lock include/linux/fs.h:719 [inline] #2: (&sb->s_type->i_mutex_key#10){++++}, at: [] __generic_file_fsync+0x9e/0x190 fs/libfs.c:989 ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 27679 Comm: syz-executor.3 Not tainted 4.14.225-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888053368040 task.stack: ffff88804f5c0000 RIP: 0010:__sanitizer_cov_trace_pc+0x29/0x50 kernel/kcov.c:71 RSP: 0018:ffff88804f5c7b60 EFLAGS: 00000246 RAX: ffff888053368040 RBX: 0000000000000026 RCX: ffffc90012c10000 RDX: 0000000000000001 RSI: 0000000000000026 RDI: ffff88809071b830 RBP: 0000000000000026 R08: ffffffff8b9939c8 R09: 0000000000000000 R10: 0000000000000000 R11: ffff888053368040 R12: ffff88809071b830 R13: 0000000000149042 R14: 0000000000000000 R15: ffff88804f5c7e88 FS: 00007f63ffde5700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002002 CR3: 00000000949ec000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: sb_permission fs/namei.c:448 [inline] inode_permission+0xe/0xf0 fs/namei.c:473 may_open+0x1ab/0x2e0 fs/namei.c:2975 do_last fs/namei.c:3424 [inline] path_openat+0x5bf/0x2970 fs/namei.c:3569 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: 0033:0x465f69 RSP: 002b:00007f63ffde5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: 0000000000000000 RSI: 0000000000141042 RDI: 0000000020002000 RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd49dc0d5f R14: 00007f63ffde5300 R15: 0000000000022000 Code: 90 90 65 48 8b 04 25 80 df 01 00 48 85 c0 74 1a 65 8b 15 cb bd ac 7e 81 e2 00 01 1f 00 75 0b 8b 90 58 13 00 00 83 fa 01 74 01 c3 <48> 8b 34 24 48 8b 88 60 13 00 00 8b 80 5c 13 00 00 48 8b 11 48