INFO: task hwrng:750 blocked for more than 143 seconds. Not tainted 6.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:hwrng state:D stack:29040 pid:750 tgid:750 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0xedb/0x5af0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6778 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6835 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x5b9/0x9d0 kernel/locking/mutex.c:747 hwrng_fillfn+0x145/0x430 drivers/char/hw_random/core.c:504 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8cfb7738 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:325 [inline] #0: ffffffff8cfb7738 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3ff/0x800 kernel/rcu/tree_exp.h:996 1 lock held by khungtaskd/29: #0: ffffffff8cfabce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8cfabce0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8cfabce0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 1 lock held by hwrng/750: #0: ffffffff8dbafee8 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0x145/0x430 drivers/char/hw_random/core.c:504 2 locks held by getty/4820: #0: ffff88802ad9a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc6/0x1490 drivers/tty/n_tty.c:2201 2 locks held by kworker/0:10/5198: 2 locks held by kworker/1:8/8166: #0: ffff888013072938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2605 #1: ffffc90005367d80 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2606 3 locks held by syz-executor.3/25467: 1 lock held by syz-executor.5/25515: 2 locks held by syz-executor.1/25530: 1 lock held by syz-executor.5/25622: 2 locks held by syz-executor.4/25629: 2 locks held by syz-executor.1/25691: 1 lock held by syz-executor.3/25694: 1 lock held by syz-executor.5/25717: #0: ffffffff8eaac728 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8eaac728 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xe00 net/core/rtnetlink.c:6555 8 locks held by syz-executor.4/25719: #0: ffff888026654418 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12f/0x250 fs/read_write.c:637 #1: ffff8880afec2488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x27d/0x500 fs/kernfs/file.c:325 #2: ffff8880200f4cb8 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2a0/0x500 fs/kernfs/file.c:326 #3: ffffffff8e144a88 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x4b0 drivers/net/netdevsim/bus.c:216 #4: ffff8880840f50e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #4: ffff8880840f50e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff8880840f50e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 #5: ffff8880840f6250 (&devlink->lock_key#5){+.+.}-{3:3}, at: nsim_drv_remove+0x4a/0x1d0 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8eaac728 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x39/0x190 drivers/net/netdevsim/netdev.c:411 #7: ffffffff8cfb7738 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:325 [inline] #7: ffffffff8cfb7738 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3ff/0x800 kernel/rcu/tree_exp.h:996 1 lock held by syz-executor.1/25764: #0: ffffffff8eaac728 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8eaac728 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x372/0xe00 net/core/rtnetlink.c:6555 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc2-syzkaller #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+0x299/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 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:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1b/0x20 drivers/acpi/processor_idle.c:112