INFO: task syz-executor.2:12244 blocked for more than 143 seconds. Not tainted 5.7.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28256 12244 7298 0x00004004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x937/0x1ff0 kernel/sched/core.c:4083 __sched_text_start+0x8/0x8 mark_held_locks+0xe0/0xe0 kernel/locking/lockdep.c:3620 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 usleep_range+0x160/0x160 kernel/time/timer.c:2093 do_wait_for_common kernel/sched/completion.c:84 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion_timeout+0x15a/0x280 kernel/sched/completion.c:157 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:694 [inline] queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] do_raw_spin_lock+0x129/0x2e0 kernel/locking/spinlock_debug.c:113 rwlock_bug.part.0+0x90/0x90 include/linux/sched.h:1329 entry_SYSCALL_64_after_hwframe+0x49/0xb3 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 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_timeout+0x162/0x280 kernel/sched/completion.c:157 wait_for_completion_io_timeout+0x280/0x280 kernel/sched/completion.c:89 usb_submit_urb+0x6ed/0x13b0 drivers/usb/core/urb.c:570 lockdep_init_map_waits+0x183/0x890 kernel/locking/lockdep.c:4139 usb_start_wait_urb+0x144/0x2b0 drivers/usb/core/message.c:63 sg_clean+0x230/0x230 drivers/usb/core/message.c:262 memset+0x20/0x40 mm/kasan/common.c:85 usb_bulk_msg+0x228/0x550 drivers/usb/core/message.c:254 proc_bulk+0x41a/0x780 drivers/usb/core/devio.c:1225 processcompl_compat+0x670/0x670 drivers/usb/core/devio.c:2110 kfree+0x1eb/0x2b0 mm/slab.c:3758 tomoyo_path_number_perm+0x411/0x4d0 security/tomoyo/file.c:736 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x463/0x620 kernel/locking/lockdep.c:3702 tomoyo_path_number_perm+0x238/0x4d0 security/tomoyo/file.c:721 usbdev_do_ioctl drivers/usb/core/devio.c:2529 [inline] usbdev_ioctl+0x543/0x31e0 drivers/usb/core/devio.c:2695 proc_do_submiturb+0x3530/0x3530 include/linux/list.h:70 rcu_read_unlock include/linux/rcupdate.h:651 [inline] __fget_files+0x30d/0x500 fs/file.c:734 __sanitizer_cov_trace_switch+0x45/0x70 kernel/kcov.c:310 ioctl_fioasync fs/ioctl.c:601 [inline] do_vfs_ioctl+0x50c/0x1360 fs/ioctl.c:704 ioctl_file_clone+0x180/0x180 fs/ioctl.c:253 rcu_lock_release include/linux/rcupdate.h:213 [inline] rcu_read_unlock include/linux/rcupdate.h:655 [inline] __fget_files+0x32f/0x500 fs/file.c:734 ksys_dup3+0x3c0/0x3c0 include/linux/compiler.h:199 __do_sys_futex kernel/futex.c:3869 [inline] __se_sys_futex kernel/futex.c:3837 [inline] __x64_sys_futex+0x380/0x4f0 kernel/futex.c:3837 proc_do_submiturb+0x3530/0x3530 include/linux/list.h:70 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x463/0x620 kernel/locking/lockdep.c:3702 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/1137: #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6740: #0: ffff8880a668e8f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by agetty/6980: #0: ffff888092dde098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900027ab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x220/0x1b30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1137 Comm: khungtaskd Not tainted 5.7.0-rc5-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 lapic_can_unplug_cpu.cold+0x3b/0x3b nmi_trigger_cpumask_backtrace+0x231/0x27e 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+0xa8c/0x1010 kernel/hung_task.c:289 reset_hung_task_detector+0x30/0x30 kernel/hung_task.c:243 kthread+0x388/0x470 kernel/kthread.c:268 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60