INFO: task hwrng:729 blocked for more than 143 seconds. Not tainted 6.4.0-syzkaller-01647-g6e2332e0ab53-dirty #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:hwrng state:D stack:29760 pid:729 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0xeda/0x5b60 kernel/sched/core.c:6710 schedule+0xe7/0x1b0 kernel/sched/core.c:6786 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6845 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x5b4/0x990 kernel/locking/mutex.c:747 hwrng_fillfn+0x145/0x430 drivers/char/hw_random/core.c:505 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c9996f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x2c/0xe30 kernel/rcu/tasks.h:522 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c9993f0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x2c/0xe30 kernel/rcu/tasks.h:522 1 lock held by khungtaskd/28: #0: ffffffff8c99a300 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6615 1 lock held by hwrng/729: #0: ffffffff8d4887a8 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0x145/0x430 drivers/char/hw_random/core.c:505 2 locks held by getty/4749: #0: ffff8880287f3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015b02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc5/0x1460 drivers/tty/n_tty.c:2176 1 lock held by syz-executor.0/5449: 2 locks held by syz-executor.0/5450: 1 lock held by syz-executor.0/5744: 1 lock held by syz-executor.0/5762: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.4.0-syzkaller-01647-g6e2332e0ab53-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2ac/0x310 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf29/0x11b0 kernel/hung_task.c:379 kthread+0x2c4/0x3a0 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5744 Comm: syz-executor.0 Not tainted 6.4.0-syzkaller-01647-g6e2332e0ab53-dirty #0