INFO: task kworker/1:3:134 blocked for more than 143 seconds. Not tainted 5.8.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/1:3 D23408 134 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x889/0x1f70 kernel/sched/core.c:4527 schedule+0xcd/0x2b0 kernel/sched/core.c:4602 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x168/0x270 kernel/sched/completion.c:138 kthread_stop+0x17d/0x770 kernel/kthread.c:596 dvb_ca_en50221_release+0x93/0x3f0 drivers/media/dvb-core/dvb_ca_en50221.c:1934 tt3650_ci_uninit drivers/media/usb/dvb-usb/pctv452e.c:364 [inline] pctv452e_usb_disconnect+0x198/0x210 drivers/media/usb/dvb-usb/pctv452e.c:1061 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:436 __device_release_driver+0x3c6/0x6f0 drivers/base/dd.c:1153 device_release_driver_internal drivers/base/dd.c:1184 [inline] device_release_driver+0x26/0x40 drivers/base/dd.c:1207 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x481/0xd90 drivers/base/core.c:3107 usb_disable_device+0x387/0x930 drivers/usb/core/message.c:1245 usb_disconnect.cold+0x27d/0x780 drivers/usb/core/hub.c:2217 hub_port_connect drivers/usb/core/hub.c:5059 [inline] hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] port_event drivers/usb/core/hub.c:5494 [inline] hub_event+0x1c93/0x4390 drivers/usb/core/hub.c:5576 process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x392/0x470 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Showing all locks held in the system: 3 locks held by kworker/0:0/5: 5 locks held by kworker/0:1/12: 1 lock held by khungtaskd/23: #0: ffffffff87313660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5825 5 locks held by kworker/0:2/103: 5 locks held by kworker/1:3/134: #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x82b/0x15f0 kernel/workqueue.c:2240 #1: ffff8881cd817da8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x85f/0x15f0 kernel/workqueue.c:2244 #2: ffff8881d448b218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:784 [inline] #2: ffff8881d448b218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c5/0x4390 drivers/usb/core/hub.c:5522 #3: ffff8881d6881218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:784 [inline] #3: ffff8881d6881218 (&dev->mutex){....}-{3:3}, at: usb_disconnect.cold+0x43/0x780 drivers/usb/core/hub.c:2208 #4: ffff8881d68841a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:784 [inline] #4: ffff8881d68841a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:975 [inline] #4: ffff8881d68841a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal drivers/base/dd.c:1181 [inline] #4: ffff8881d68841a8 (&dev->mutex){....}-{3:3}, at: device_release_driver+0x1c/0x40 drivers/base/dd.c:1207 1 lock held by in:imklog/226: #0: ffff8881cb330870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 2 locks held by agetty/234: #0: ffff8881cfddf098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000a2a2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 6 locks held by kworker/0:3/3029: 6 locks held by kworker/0:4/3031: 5 locks held by kworker/0:6/3048: #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881d88a2538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x82b/0x15f0 kernel/workqueue.c:2240 #1: ffff8881d780fda8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x85f/0x15f0 kernel/workqueue.c:2244 #2: ffff8881d44ab218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:784 [inline] #2: ffff8881d44ab218 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c5/0x4390 drivers/usb/core/hub.c:5522 #3: ffff8881c2ccd218 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:784 [inline] #3: ffff8881c2ccd218 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:887 #4: ffff8881d215f1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:784 [inline] #4: ffff8881d215f1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7a/0x4a0 drivers/base/dd.c:887 4 locks held by kdvb-ca-0:0/10538: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xf6/0x16e lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x74/0xb6 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1da/0x1f4 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd6a/0xfd0 kernel/hung_task.c:295 kthread+0x392/0x470 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 10538 Comm: kdvb-ca-0:0 Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:write_comp_data+0x13/0x80 kernel/kcov.c:218 Code: 48 8b 80 28 13 00 00 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 49 89 f2 65 8b 05 d6 f2 c1 7e 65 48 8b 34 25 40 ef 01 00 00 01 ff 00 74 0f f6 c4 01 74 59 8b 86 34 13 00 00 85 c0 74 4f RSP: 0018:ffff8881c8ec7748 EFLAGS: 00000002 RAX: 0000000080000002 RBX: 0000000000000002 RCX: ffffffff81f8c17a RDX: 0000000000000009 RSI: ffff8881cfc0b200 RDI: 0000000000000001 RBP: ffffffff861e2640 R08: 0000000000000009 R09: ffff8881c8ec79b6 R10: 0000000000000009 R11: 0000000000000001 R12: 000000000000000a R13: ffffffff8607b5cb R14: 0000000000000009 R15: ffff8881c8ec7870 FS: 0000000000000000(0000) GS:ffff8881db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6c396a4000 CR3: 00000001ac680000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_switch+0x45/0x70 kernel/kcov.c:320 vsnprintf+0x8ca/0x14f0 lib/vsprintf.c:2586 sprintf+0xc0/0x100 lib/vsprintf.c:2819 print_time kernel/printk/printk.c:1307 [inline] print_prefix kernel/printk/printk.c:1333 [inline] msg_print_text+0x4da/0x560 kernel/printk/printk.c:1352 console_unlock+0x31b/0xcd0 kernel/printk/printk.c:2476 vprintk_emit+0x1b2/0x460 kernel/printk/printk.c:2029 vprintk_func+0x8b/0x133 kernel/printk/printk_safe.c:393 printk+0xba/0xed kernel/printk/printk.c:2078 dvb_usb_generic_rw.cold+0x33/0x56 drivers/media/usb/dvb-usb/dvb-usb-urb.c:36 tt3650_ci_msg+0x1b1/0x2f0 drivers/media/usb/dvb-usb/pctv452e.c:126 tt3650_ci_msg_locked drivers/media/usb/dvb-usb/pctv452e.c:157 [inline] tt3650_ci_poll_slot_status+0xe6/0x180 drivers/media/usb/dvb-usb/pctv452e.c:333 dvb_ca_en50221_check_camstatus+0x108/0x320 drivers/media/dvb-core/dvb_ca_en50221.c:234 dvb_ca_en50221_thread_state_machine drivers/media/dvb-core/dvb_ca_en50221.c:1128 [inline] dvb_ca_en50221_thread+0x252/0x13d0 drivers/media/dvb-core/dvb_ca_en50221.c:1317 kthread+0x392/0x470 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294