INFO: task syz.2.397:7670 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.397 stat
task:syz.2.397 state:D stack:24848 pid:7670 tgid:7670 ppid:5615 task_flags:0x40044c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5527 [inline]
__schedule+0x17dd/0x5940 kernel/sched/core.c:7295
__schedule_loop kernel/sched/core.c:7372 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7387
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7444
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
nfsd_umount+0x41/0x60 fs/nfsd/nfsctl.c:1374
deactivate_locked_super+0xbc/0x110 fs/super.c:589
cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
task_work_run+0x1d9/0x260 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:1008
do_group_exit+0x22d/0x2f0 kernel/exit.c:1151
get_signal+0x1216/0x12c0 kernel/signal.c:3051
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3ddd15e98e
RSP: 002b:00007f3dddfb6f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f3dddfb76c0 RCX: 00007f3ddd15e98e
RDX: 00007f3dddfb6fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f3ddd23503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3ddd4263f8 R14: 00007f3ddd426360 R15: 00007ffc26c185d8
Showing all locks held in the system:
locks held by pr/ttyS0/16: 2, last CPU#0:
#0: ffffffff8ee363b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8ee363b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8ee363b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
#1: ffffffff9afb0538 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
#1: ffffffff9afb0538 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/32: 1, last CPU#1:
#0: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by acpid/4970: 3, last CPU#1:
#0: ffff888026d0c158 (&mousedev->mutex#2){+.+.}-{4:4}, at: mousedev_open_device+0x27/0x150 drivers/input/mousedev.c:423
#1: ffff8880593722b8 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline]
#1: ffff8880593722b8 (&dev->mutex#2){+.+.}-{4:4}, at: input_open_device+0x4f/0x560 drivers/input/input.c:652
#2: ffff88802bdbd140 (&dev->pm_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#2: ffff88802bdbd140 (&dev->pm_mutex){+.+.}-{4:4}, at: bcm5974_open+0x8a/0x120 drivers/input/mouse/bcm5974.c:875
locks held by klogd/4974: 1, last CPU#1:
#0: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0xae/0x550 net/core/sock.c:3658
locks held by getty/5376: 2, on CPU#1:
#0: ffff8880368460a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322e2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/0:4/5701: 7, on CPU#0:
#0: ffff888022695140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888022695140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888022695140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline]
#0: ffff888022695140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482
#1: ffffc90004da7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004da7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004da7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline]
#1: ffffc90004da7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482
#2: ffff88802a0b91d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802a0b91d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912
#3: ffff88801bf4b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#3: ffff88801bf4b1d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
#4: ffff88801bf481a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff88801bf481a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
#5: ffffffff8fedee60 (input_mutex){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline]
#5: ffffffff8fedee60 (input_mutex){+.+.}-{4:4}, at: input_register_device+0xa7f/0x1150 drivers/input/input.c:2447
#6: ffff8880593722b8 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline]
#6: ffff8880593722b8 (&dev->mutex#2){+.+.}-{4:4}, at: input_register_handle+0x184/0x4f0 drivers/input/input.c:2692
locks held by kworker/0:6/5746: 6, on CPU#0:
#0: ffff888022695140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888022695140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888022695140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline]
#0: ffff888022695140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482
#1: ffffc90004f87c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004f87c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004f87c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3364 [inline]
#1: ffffc90004f87c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3482
#2: ffff88802a0431d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#2: ffff88802a0431d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912
#3: ffff888022ae31d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#3: ffff888022ae31d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
#4: ffff8880594af1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff8880594af1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
#5: ffffffff8edf7d88 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2b0 kernel/umh.c:212
locks held by udevd/5801: 5, on CPU#1:
#0: ffff888049166690 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x7d0/0x1c10 security/integrity/ima/ima_main.c:319
#1: ffff8880227e5518 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183
#2: ffff888035425480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
#3: ffff88807bf71788 (kn->active#28){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#3: ffff88807bf71788 (kn->active#28){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
#4: ffff88801bf4b1d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline]
#4: ffff88801bf4b1d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by syz.2.397/7670: 2, on CPU#0:
#0: ffff888059db40e8 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888059db40e8 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff888059db40e8 (&type->s_umount_key#78){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f2a0020 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
locks held by syz.5.611/8682: 3, on CPU#1:
#0: ffff888025aef970 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259
#1: ffff88802b82a460 (sb_writers#15){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88802b82a460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#2: ffffffff8f2a0020 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:869
locks held by syz-executor/8816: 2, on CPU#1:
#0: ffff88807c1600e8 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88807c1600e8 (&type->s_umount_key#78){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88807c1600e8 (&type->s_umount_key#78){++++}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:617
#1: ffffffff8f2a0020 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:590
locks held by syz.6.1163/11501: 2, on CPU#1:
#0: ffffffff904dbbe8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8f2a0020 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_expkey_set_reqs_doit+0xfe/0xaf0 fs/nfsd/export.c:563
locks held by syz-executor/11674: 9, last CPU#1:
#0: ffff88802b8ac460 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88802b8ac460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
#1: ffff88804932c080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
#2: ffff888029447788 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
#2: ffff888029447788 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337
#3: ffffffff8fce2540 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x6d0 drivers/net/netdevsim/bus.c:184
#4: ffff888029a4d128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#4: ffff888029a4d128 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
#5: ffff88807a338258 (&devlink->lock_key#13){+.+.}-{4:4}, at: nsim_drv_probe+0xfb/0xbb0 drivers/net/netdevsim/dev.c:1583
#6: ffffffff9046ad40 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1068 [inline]
#6: ffffffff9046ad40 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x87f/0x1150 drivers/net/netdevsim/netdev.c:1162
#7: ffff88805b9ece70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: register_netdevice+0x1871/0x1eb0 net/core/dev.c:11540
#8: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#8: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#8: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#8: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: is_module_address+0x17/0xf0 kernel/module/main.c:3893
locks held by syz.7.1224/11731: 2, last CPU#1:
#0: ffff8880252403b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:586 [inline]
#0: ffff8880252403b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
#1: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ef5c7a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302
locks held by cmp/11741: 1, last CPU#1:
#0: ffff88802cda4378 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:530 [inline]
#0: ffff88802cda4378 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:delay_tsc+0x5d/0xd0 arch/x86/lib/delay.c:77
Code: 89 d7 49 c1 e7 20 49 09 c7 4d 29 f7 49 39 df 73 55 bf 01 00 00 00 e8 c2 22 a0 f5 65 48 8b 05 4a 5b c7 07 48 85 c0 74 1c f3 90 01 00 00 00 e8 59 21 a0 f5 e8 44 7d 01 00 39 c5 75 0e 0f 01 f9
RSP: 0018:ffffc900001578b8 EFLAGS: 00000082
RAX: 8000000000000001 RBX: 0000000000000899 RCX: ffffffff9ac59501
RDX: 0000000000000001 RSI: ffffffff8c6f0560 RDI: 00000000ffffffff
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8bf4f470 R12: 1ffffffff35f6101
R13: 00000000ffffffff R14: 000000f3cf103a88 R15: 00000000000002af
FS: 0000000000000000(0000) GS:ffff88812485b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f46f6ffe368 CR3: 00000000565fc000 CR4: 00000000003526f0
Call Trace:
udelay include/asm-generic/delay.h:62 [inline]
wait_for_lsr+0x147/0x2f0 drivers/tty/serial/8250/8250_port.c:2019
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
__serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3345
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271
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