INFO: task syz-executor192:3608 blocked for more than 143 seconds. Not tainted 6.0.0-rc4-syzkaller-00137-g506357871c18 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor192 state:D stack:25856 pid: 3608 ppid: 3607 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5182 [inline] __schedule+0x957/0xe20 kernel/sched/core.c:6494 schedule+0xcb/0x190 kernel/sched/core.c:6570 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6629 __mutex_lock_common+0xecf/0x26c0 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 blkdev_put+0x100/0x730 block/bdev.c:910 blkdev_close+0x55/0x80 block/fops.c:499 __fput+0x3b9/0x820 fs/file_table.c:320 task_work_run+0x146/0x1c0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x55e/0x20a0 kernel/exit.c:795 do_group_exit+0x23b/0x2f0 kernel/exit.c:925 get_signal+0x172f/0x1780 kernel/signal.c:2857 arch_do_signal_or_restart+0x8d/0x750 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop+0x74/0x160 kernel/entry/common.c:166 exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f9a46aa3b39 RSP: 002b:00007fff1892e798 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffe00 RBX: 00007fff1892e7e8 RCX: 00007f9a46aa3b39 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9a46a62bc0 R13: 431bde82d7b634db R14: 00007fff1892e7e0 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cd20a70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cd21270 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8cd208a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3285: #0: ffff88802753a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc90002d232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6e8/0x1e50 drivers/tty/n_tty.c:2177 1 lock held by syz-executor192/3608: #0: ffff88801e9e84c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x730 block/bdev.c:910 1 lock held by udevd/3610: #0: ffff88801e9e84c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0xfd/0xa40 block/bdev.c:812 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.0.0-rc4-syzkaller-00137-g506357871c18 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x47c/0x4b0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x169/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xcd5/0xd20 kernel/hung_task.c:369 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 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:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry drivers/acpi/processor_idle.c:555 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_enter+0x43d/0x7a0 drivers/acpi/processor_idle.c:692