INFO: task kworker/0:6:3128 blocked for more than 143 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:6 D23432 3128 2 0x80004000 Workqueue: usb_hub_wq hub_event Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4154 schedule_timeout+0x440/0xb20 kernel/time/timer.c:1895 usb_start_wait_urb.constprop.0+0x29d/0x2e0 drivers/net/usb/kaweth.c:1238 kaweth_internal_control_msg drivers/net/usb/kaweth.c:1274 [inline] kaweth_control.constprop.0+0x360/0x4f0 drivers/net/usb/kaweth.c:269 kaweth_set_urb_size drivers/net/usb/kaweth.c:309 [inline] kaweth_probe.cold+0x886/0x1359 drivers/net/usb/kaweth.c:1084 usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:374 really_probe+0x290/0xac0 drivers/base/dd.c:551 driver_probe_device+0x223/0x350 drivers/base/dd.c:724 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431 __device_attach+0x217/0x390 drivers/base/dd.c:897 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0x1459/0x1bf0 drivers/base/core.c:2500 usb_set_configuration+0xece/0x1840 drivers/usb/core/message.c:2025 usb_generic_driver_probe+0x9d/0xe0 drivers/usb/core/generic.c:241 usb_probe_device+0xd9/0x230 drivers/usb/core/driver.c:272 really_probe+0x290/0xac0 drivers/base/dd.c:551 driver_probe_device+0x223/0x350 drivers/base/dd.c:724 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431 __device_attach+0x217/0x390 drivers/base/dd.c:897 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491 device_add+0x1459/0x1bf0 drivers/base/core.c:2500 usb_new_device.cold+0x540/0xcd0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5563 process_one_work+0x94b/0x1620 kernel/workqueue.c:2266 process_scheduled_works kernel/workqueue.c:2328 [inline] worker_thread+0x7ab/0xe20 kernel/workqueue.c:2414 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.3:20706 blocked for more than 143 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28472 20706 378 0x80004006 Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4154 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1249 close_files fs/file.c:388 [inline] put_files_struct fs/file.c:416 [inline] put_files_struct+0x1d8/0x2e0 fs/file.c:413 exit_files+0x7e/0xa0 fs/file.c:445 do_exit+0xb36/0x2c80 kernel/exit.c:796 do_group_exit+0x125/0x340 kernel/exit.c:899 get_signal+0x480/0x2470 kernel/signal.c:2739 do_signal+0x88/0x1490 arch/x86/kernel/signal.c:813 exit_to_usermode_loop+0x1a2/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ad51 Code: 45 76 7c 00 ff d0 48 8b 04 24 8b 54 24 08 48 69 d2 e8 03 00 00 48 89 ec 48 89 44 24 08 89 54 24 10 c3 cc cc cc cc cc cc cc 48 <89> e5 64 48 8b 04 25 f8 ff ff ff 48 8b 48 30 48 8b 91 c0 00 00 00 RSP: 002b:00007fffbb4a1bb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: 0000000000000000 RBX: 00000000000cc3b8 RCX: 000000000045ad51 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fffbb4a1bc0 RBP: 0000000000000001 R08: 00000000bc4eedb3 R09: 00000000bc4eedb7 R10: 00007fffbb4a1cb0 R11: 0000000000000293 R12: 000000000076bf00 R13: 000000000076c900 R14: 00000000000cb826 R15: 000000000076c04c INFO: task syz-executor.1:20771 blocked for more than 144 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28472 20771 376 0x80004006 Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4154 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1249 close_files fs/file.c:388 [inline] put_files_struct fs/file.c:416 [inline] put_files_struct+0x1d8/0x2e0 fs/file.c:413 exit_files+0x7e/0xa0 fs/file.c:445 do_exit+0xb36/0x2c80 kernel/exit.c:796 do_group_exit+0x125/0x340 kernel/exit.c:899 get_signal+0x480/0x2470 kernel/signal.c:2739 do_signal+0x88/0x1490 arch/x86/kernel/signal.c:813 exit_to_usermode_loop+0x1a2/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ad51 Code: 45 76 7c 00 ff d0 48 8b 04 24 8b 54 24 08 48 69 d2 e8 03 00 00 48 89 ec 48 89 44 24 08 89 54 24 10 c3 cc cc cc cc cc cc cc 48 <89> e5 64 48 8b 04 25 f8 ff ff ff 48 8b 48 30 48 8b 91 c0 00 00 00 RSP: 002b:00007ffe38645c10 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: fffffffffffffdfc RBX: 00000000000cd060 RCX: 000000000045ad51 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffe38645c20 RBP: 0000000000000001 R08: 00000000bc4eedb3 R09: 00000000bc4eedb7 R10: 00007ffe38645d10 R11: 0000000000000293 R12: 000000000076bf00 R13: 000000000076c900 R14: 00000000000cc59d R15: 000000000076c0ec Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: ffffffff87108b60 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5331 1 lock held by in:imklog/241: 5 locks held by kworker/0:6/3128: #0: ffff8881d8900128 ((wq_completion)usb_hub_wq){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8881d8900128 ((wq_completion)usb_hub_wq){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881d8900128 ((wq_completion)usb_hub_wq){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8881d8900128 ((wq_completion)usb_hub_wq){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8881d8900128 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8881d8900128 ((wq_completion)usb_hub_wq){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8881d8900128 ((wq_completion)usb_hub_wq){+.+.}, at: process_one_work+0x82a/0x1620 kernel/workqueue.c:2237 #1: ffff8881d554fdd0 ((work_completion)(&hub->events)){+.+.}, at: process_one_work+0x85e/0x1620 kernel/workqueue.c:2241 #2: ffff8881d4d8b200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #2: ffff8881d4d8b200 (&dev->mutex){....}, at: hub_event+0x1be/0x4300 drivers/usb/core/hub.c:5509 #3: ffff8881ccf0b200 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #3: ffff8881ccf0b200 (&dev->mutex){....}, at: __device_attach+0x7b/0x390 drivers/base/dd.c:874 #4: ffff8881aa80d190 (&dev->mutex){....}, at: device_lock include/linux/device.h:771 [inline] #4: ffff8881aa80d190 (&dev->mutex){....}, at: __device_attach+0x7b/0x390 drivers/base/dd.c:874 2 locks held by agetty/20565: #0: ffff8881cc688090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000fc832e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 5.6.0-rc7-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+0xef/0x16e lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1db/0x207 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa99/0xfd0 kernel/hung_task.c:289 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0x28/0x300 arch/x86/kernel/process.c:695