INFO: task syz.5.2401:11966 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.5.2401 state:D stack:25560 pid:11966 tgid:11963 ppid:9233 task_flags:0x40054c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5526 [inline]
__schedule+0x1259/0x6920 kernel/sched/core.c:7276
__schedule_loop kernel/sched/core.c:7353 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7368
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7425
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xccb/0x1bd0 kernel/locking/mutex.c:821
nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
nfsd_umount+0x3b/0x60 fs/nfsd/nfsctl.c:1372
deactivate_locked_super+0xbd/0x140 fs/super.c:603
deactivate_super fs/super.c:632 [inline]
deactivate_super+0xea/0x110 fs/super.c:628
cleanup_mnt+0x21f/0x450 fs/namespace.c:1317
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x951/0x2ae0 kernel/exit.c:1011
do_group_exit+0xd5/0x2a0 kernel/exit.c:1154
get_signal+0x1ec7/0x21e0 kernel/signal.c:3051
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x139/0x700 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+0x661/0x790 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc89b99e159
RSP: 002b:00007fc89c8a6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: 0000000000000000 RBX: 00007fc89bc25fa0 RCX: 00007fc89b99e159
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007fc89ba3503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc89bc26038 R14: 00007fc89bc25fa0 R15: 00007ffe114d4ad8
Showing all locks held in the system:
locks held by pr/ttyS0/16: 2, last CPU#1:
#0: ffffffff8edd8738 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8edd8738 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8edd8738 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291
#1: ffffffff9bc68c78 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
#1: ffffffff9bc68c78 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x64/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/32: 1, last CPU#0:
#0: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by kworker/u8:4/59: 3, last CPU#0:
#0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc9000201fd08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff88807c47f258 (&devlink->lock_key#18){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xd20 drivers/net/netdevsim/dev.c:834
locks held by kworker/u8:8/1004: 5, last CPU#0:
#0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90004a9fd08 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffffffff8ec7ca50 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20 kernel/jump_label.c:222
#3: ffffffff8ef40f00 (jump_label_mutex){+.+.}-{4:4}, at: jump_label_lock kernel/jump_label.c:27 [inline]
#3: ffffffff8ef40f00 (jump_label_mutex){+.+.}-{4:4}, at: static_key_enable_cpuslocked+0xb5/0x270 kernel/jump_label.c:207
#4: ffffffff8ec9c3c0 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145
locks held by getty/5359: 2, last CPU#0:
#0: ffff888037c150a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffff888037c15128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: tty_write_lock drivers/tty/tty_io.c:939 [inline]
#1: ffff888037c15128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: iterate_tty_write drivers/tty/tty_io.c:958 [inline]
#1: ffff888037c15128 (&tty->atomic_write_lock){+.+.}-{4:4}, at: file_tty_write.isra.0+0x24b/0x890 drivers/tty/tty_io.c:1054
locks held by syz.4.1466/9153: 2, on CPU#0:
#0: ffff8880535320e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880535320e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff8880535320e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: deactivate_super fs/super.c:631 [inline]
#0: ffff8880535320e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: deactivate_super+0xe2/0x110 fs/super.c:628
#1: ffffffff8f2893c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
locks held by syz.3.1517/9362: 1, last CPU#0:
#0: ffff888071a8f480 (&ima_iint_mutex_key[depth]#2){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
locks held by syz.2.2355/11829: 1, last CPU#0:
#0: ffff88805cace690 (&ima_iint_mutex_key[depth]#2){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
locks held by syz.5.2401/11966: 2, on CPU#1:
#0: ffff8880503780e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff8880503780e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff8880503780e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: deactivate_super fs/super.c:631 [inline]
#0: ffff8880503780e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: deactivate_super+0xe2/0x110 fs/super.c:628
#1: ffffffff8f2893c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
locks held by kworker/u8:1/12454: 3, last CPU#0:
#0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
#1: ffffc90004ecfd08 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
#2: ffff8880b8426398 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x124/0x1d0 kernel/time/timer.c:1004
locks held by syz-executor/12985: 2, on CPU#0:
#0: ffff88806a7960e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff88806a7960e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
#0: ffff88806a7960e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: deactivate_super fs/super.c:631 [inline]
#0: ffff88806a7960e8 (&type->s_umount_key#77){+.+.}-{4:4}, at: deactivate_super+0xe2/0x110 fs/super.c:628
#1: ffffffff8f2893c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
locks held by syz.3.2919/13911: 3, on CPU#0:
#0: ffff8880507b3eb0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
#1: ffff88802a59e460 (sb_writers#20){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
#2: ffffffff8f2893c0 (nfsd_mutex){+.+.}-{4:4}, at: write_versions+0x9d/0xba0 fs/nfsd/nfsctl.c:708
locks held by syz.3.2919/13914: 1, on CPU#1:
#0: ffff8880507b3eb0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1259
locks held by syz.0.3296/15074: 1, last CPU#0:
#0: ffff888059b9e378 (&ima_iint_mutex_key[depth]#2){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
locks held by syz.7.3612/16193: 5, last CPU#0:
#0: ffffffff90d80d68 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffff88802b001128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
#1: ffff88802b001128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#1: ffff88802b001128 (&dev->mutex){....}-{4:4}, at: devlink_get_from_attrs_lock+0x1f5/0x4d0 net/devlink/netlink.c:235
#2: ffff88802b8e8258 (&devlink->lock_key#8){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#2: ffff88802b8e8258 (&devlink->lock_key#8){+.+.}-{4:4}, at: devlink_get_from_attrs_lock+0x202/0x4d0 net/devlink/netlink.c:235
#3: ffffffff90cd1700 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x1a6/0x970 drivers/net/netdevsim/netdev.c:1193
#4: ffffffff8edf8328 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
locks held by syz.6.3624/16223: 2, last CPU#0:
#0: ffff8880541fa9f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
#0: ffff8880541fa9f8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x22c/0xa00 mm/mmap.c:1323
#1: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#1: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
locks held by syz.9.3627/16230: 1, on CPU#1:
#0: ffffffff90cd1700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff90cd1700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
#0: ffffffff90cd1700 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xac3/0x2620 net/core/rtnetlink.c:4219
locks held by fido_id/16231: 2, last CPU#0:
#0: ffff888049801078 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
#0: ffff888049801078 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x22c/0xa00 mm/mmap.c:1323
#1: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#1: ffffffff8edec420 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
=============================================
NMI backtrace for cpu 0
CPU: 0 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 08/26/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x21f/0x2a0 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 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 08/26/2026
RIP: 0010:nbcon_emit_next_record+0x248/0xa70 kernel/printk/nbcon.c:1110
Code: 00 00 00 00 00 fc ff df 48 01 c5 48 c7 45 00 00 00 00 00 48 c7 45 08 00 00 00 00 c7 45 14 00 00 00 00 48 8b 84 24 10 01 00 00 <65> 48 2b 05 c8 db a1 12 0f 85 03 07 00 00 48 81 c4 18 01 00 00 89
RSP: 0018:ffffc90000157b70 EFLAGS: 00000082
RAX: aac4535e1e680600 RBX: 0000000000000001 RCX: 0000000000000001
RDX: ffff88801f298000 RSI: ffffffff81ea640c RDI: ffff88801f298000
RBP: fffff5200002af75 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 205d323354202020 R12: 000000000000221d
R13: ffffffff8fbd64c0 R14: 0000000000000001 R15: 000000000000221c
FS: 0000000000000000(0000) GS:ffff888123c5c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc606fc8d74 CR3: 0000000089f0f000 CR4: 00000000003526f0
Call Trace:
nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157
nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245