INFO: task syz.1.3316:14893 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3316 state:D stack:27432 pid:14893 tgid:14891 ppid:11516 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5535 [inline]
__schedule+0x1b47/0x5c60 kernel/sched/core.c:7305
__schedule_loop kernel/sched/core.c:7382 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7397
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7454
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:874
nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:117
vfs_write+0x296/0xba0 fs/read_write.c:685
ksys_write+0x150/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f76c2d9e159
RSP: 002b:00007f76c3d4a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f76c3025fa0 RCX: 00007f76c2d9e159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f76c2e3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f76c3026038 R14: 00007f76c3025fa0 R15: 00007ffe0d64de18
Showing all locks held in the system:
locks held by kworker/u8:1/13: 3, last CPU#0:
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90000127c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90000127c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90000127c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90000127c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff88802b81d258 (&devlink->lock_key#8){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb30 drivers/net/netdevsim/dev.c:834
locks held by khungtaskd/34: 1, last CPU#0:
#0: ffffffff8f15c2a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8f15c2a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8f15c2a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by kworker/0:1H/2000: 2, last CPU#0:
#0: ffff88813fe0a948 ((wq_completion)events_highpri){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813fe0a948 ((wq_completion)events_highpri){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813fe0a948 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88813fe0a948 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90006957c40 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90006957c40 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90006957c40 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90006957c40 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
locks held by getty/5365: 2, on CPU#0:
#0: ffff8880363760a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032262e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by udevd/5612: 4, on CPU#0:
#0: ffff88806985af38 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183
#1: ffff888059422880 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
#2: ffff888034395968 (kn->active#5){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff888034395968 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
#3: ffff888041780390 (&wdata->state.sync){+.+.}-{4:4}, at: wiimote_cmd_acquire drivers/hid/hid-wiimote.h:323 [inline]
#3: ffff888041780390 (&wdata->state.sync){+.+.}-{4:4}, at: wiimod_battery_get_property+0x5e/0x240 drivers/hid/hid-wiimote-modules.c:214
locks held by udevd/6054: 3, on CPU#0:
#0: ffff88802c3bd110 (&evdev->mutex){+.+.}-{4:4}, at: evdev_open_device drivers/input/evdev.c:389 [inline]
#0: ffff88802c3bd110 (&evdev->mutex){+.+.}-{4:4}, at: evdev_open+0x2da/0x5d0 drivers/input/evdev.c:483
#1: ffff88802bdb62b8 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline]
#1: ffff88802bdb62b8 (&dev->mutex#2){+.+.}-{4:4}, at: input_open_device+0x4f/0x560 drivers/input/input.c:652
#2: ffff888041780390 (&wdata->state.sync){+.+.}-{4:4}, at: wiimote_cmd_acquire drivers/hid/hid-wiimote.h:323 [inline]
#2: ffff888041780390 (&wdata->state.sync){+.+.}-{4:4}, at: wiimod_ir_change+0x150/0x850 drivers/hid/hid-wiimote-modules.c:636
locks held by kworker/0:6/8013: 3, on CPU#0:
#0: ffff88813fe0ad48 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88813fe0ad48 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88813fe0ad48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#0: ffff88813fe0ad48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#1: ffffc90005097c40 ((work_completion)(&wdata->init_worker)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90005097c40 ((work_completion)(&wdata->init_worker)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90005097c40 ((work_completion)(&wdata->init_worker)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline]
#1: ffffc90005097c40 ((work_completion)(&wdata->init_worker)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578
#2: ffff888041780390 (&wdata->state.sync){+.+.}-{4:4}, at: wiimote_cmd_acquire_noint drivers/hid/hid-wiimote.h:328 [inline]
#2: ffff888041780390 (&wdata->state.sync){+.+.}-{4:4}, at: wiimote_init_hotplug drivers/hid/hid-wiimote-core.c:1108 [inline]
#2: ffff888041780390 (&wdata->state.sync){+.+.}-{4:4}, at: wiimote_init_worker+0xf0a/0x2f00 drivers/hid/hid-wiimote-core.c:1220
locks held by syz.3.2494/12553: 2, on CPU#0:
#0: ffff88802a40e0e8 (&type->s_umount_key#89){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88802a40e0e8 (&type->s_umount_key#89){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88802a40e0e8 (&type->s_umount_key#89){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
#1: ffffffff8f49efe0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
locks held by syz.1.3316/14893: 3, on CPU#0:
#0: ffff88807fa787f0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x118/0x160 fs/file.c:1408
#1: ffff888078af8460 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff888078af8460 (sb_writers#21){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8f49efe0 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:874
locks held by syz.4.3981/16680: 1, on CPU#0:
#0: ffff888032fd9a58 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#0: ffff888032fd9a58 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
#0: ffff888032fd9a58 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
locks held by syz.5.4027/16804: 1, last CPU#0:
#0: ffff888036800e70 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x1e3/0xd70 net/unix/af_unix.c:2587
locks held by syz-executor/16824: 2, last CPU#0:
#0: ffff88807ebb2460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
#1: ffff88807ce414d0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
#1: ffff88807ce414d0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline]
#1: ffff88807ce414d0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline]
#1: ffff88807ce414d0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:5101
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:377 [inline]
watchdog+0x1058/0x10d0 kernel/hung_task.c:598
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245