INFO: task hwrng:770 blocked for more than 143 seconds.
Not tainted 6.1.75-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:hwrng state:D stack:27736 pid:770 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
hwrng_fillfn+0xe2/0x3b0 drivers/char/hw_random/core.c:506
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8d12a490 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8d12ac90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
#0: ffffffff8d12a2c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:318 [inline]
#0: ffffffff8d12a2c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:759 [inline]
#0: ffffffff8d12a2c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
1 lock held by hwrng/770:
#0: ffffffff8d879c48 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0xe2/0x3b0 drivers/char/hw_random/core.c:506
2 locks held by getty/3304:
#0: ffff888141e7b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2188
2 locks held by kworker/1:5/32234:
#0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
#1: ffffc9000b127d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
3 locks held by kworker/0:4/502:
2 locks held by syz-executor.0/25178:
3 locks held by kworker/u4:6/783:
1 lock held by syz-executor.0/14240:
3 locks held by syz-executor.0/14245:
1 lock held by syz-executor.3/19584:
4 locks held by kvm-nx-lpage-re/19623:
#0: ffffffff8d152a68 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:442 [inline]
#0: ffffffff8d152a68 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_attach_task_all+0x23/0xe0 kernel/cgroup/cgroup-v1.c:61
#1: ffffffff8cfc77f0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock+0xd/0x30 kernel/cgroup/cgroup.c:2444
#2: ffffffff8d152c50 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_task_all+0x2d/0xe0 kernel/cgroup/cgroup-v1.c:62
#3: ffffffff8d12f8b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#3: ffffffff8d12f8b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3b0/0x8a0 kernel/rcu/tree_exp.h:950
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.75-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf88/0xfd0 kernel/hung_task.c:377
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572