INFO: task hwrng:750 blocked for more than 143 seconds. Not tainted 6.7.0-rc7-syzkaller-00029-g8735c7c84d1b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:hwrng state:D stack:29600 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 khungtaskd/29: #0: ffffffff8cfab760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8cfab760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8cfab760 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614 1 lock held by hwrng/750: #0: ffffffff8dbb0128 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0x145/0x430 drivers/char/hw_random/core.c:504 4 locks held by kworker/u4:9/2834: 2 locks held by getty/4820: #0: ffff8880260da0a0 (&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/0:3/5157: #0: ffff888013072938 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2602 #1: ffffc90004387d80 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2603 2 locks held by syz-executor.4/3221: 2 locks held by syz-executor.4/3236: 1 lock held by syz-executor.3/3277: 2 locks held by syz-executor.3/3379: 8 locks held by syz-executor.3/3421: #0: ffff88802a462418 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12f/0x250 fs/read_write.c:637 #1: ffff8880b39b9488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x27d/0x500 fs/kernfs/file.c:325 #2: ffff88801ee3a918 (kn->active#50){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2a0/0x500 fs/kernfs/file.c:326 #3: ffffffff8e144dc8 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xd2/0x4b0 drivers/net/netdevsim/bus.c:216 #4: ffff8880364400e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #4: ffff8880364400e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff8880364400e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 #5: ffff888036446250 (&devlink->lock_key#8){+.+.}-{3:3}, at: nsim_drv_remove+0x4a/0x1d0 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8eaad128 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x39/0x190 drivers/net/netdevsim/netdev.c:411 #7: ffffffff8cfb71b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline] #7: ffffffff8cfb71b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x6b1/0x800 kernel/rcu/tree_exp.h:996 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc7-syzkaller-00029-g8735c7c84d1b #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+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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.7.0-rc7-syzkaller-00029-g8735c7c84d1b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events nsim_dev_trap_report_work RIP: 0010:find_stack lib/stackdepot.c:349 [inline] RIP: 0010:__stack_depot_save+0x14e/0x520 lib/stackdepot.c:390 Code: 31 d8 c1 c3 0e 41 29 d8 44 31 c0 41 c1 c8 08 44 29 c0 89 c3 48 8b 05 f9 15 16 0e 89 d9 23 0d e9 15 16 0e 48 8d 0c c8 48 8b 29 <48> 85 ed 75 0b eb 70 48 8b 6d 00 48 85 ed 74 67 39 5d 08 75 f2 44 RSP: 0018:ffffc900000e7858 EFLAGS: 00000002 RAX: ffff88823b400000 RBX: 00000000145121a1 RCX: ffff88823b490d08 RDX: 000000000000000c RSI: 0000000000000003 RDI: 00000000f9c6dd55 RBP: ffff88805bd0fb00 R08: 00000000fa704a2a R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000004 R12: 0000000000000000 R13: 0000000000000000 R14: ffffc900000e78c0 R15: 000000000000000c FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2c906ce866 CR3: 000000000cd77000 CR4: 0000000000350ef0 Call Trace: kasan_save_stack+0x43/0x50 mm/kasan/common.c:46 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:492 insert_work+0x38/0x230 kernel/workqueue.c:1647 __queue_work+0x62e/0x11d0 kernel/workqueue.c:1796 __queue_delayed_work+0x1bf/0x270 kernel/workqueue.c:1947 queue_delayed_work_on+0x106/0x130 kernel/workqueue.c:1983 queue_delayed_work include/linux/workqueue.h:577 [inline] schedule_delayed_work include/linux/workqueue.h:691 [inline] nsim_dev_trap_report_work+0x9ba/0xc70 drivers/net/netdevsim/dev.c:842 process_one_work+0x886/0x15d0 kernel/workqueue.c:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2781 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