INFO: task kworker/0:5:5920 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:5 state:D stack:26232 pid:5920 tgid:5920 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events_freezable update_balloon_stats_func
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
percpu_rwsem_wait+0x1e6/0x510 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0x100/0x150 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
cpus_read_lock+0x14a/0x160 kernel/cpu.c:491
all_vm_events+0x1a/0x1f0 mm/vmstat.c:135
update_balloon_vm_stats+0xaa/0x9a0 drivers/virtio/virtio_balloon.c:361
update_balloon_stats+0x8b/0x680 drivers/virtio/virtio_balloon.c:408
stats_handle_request drivers/virtio/virtio_balloon.c:452 [inline]
update_balloon_stats_func+0xfe/0x2d0 drivers/virtio/virtio_balloon.c:548
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
INFO: task kworker/0:6:5922 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:6 state:D stack:26184 pid:5922 tgid:5922 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: events vmstat_shepherd
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
percpu_rwsem_wait+0x1e6/0x510 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0x100/0x150 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
cpus_read_lock+0x14a/0x160 kernel/cpu.c:491
vmstat_shepherd+0x1c/0x240 mm/vmstat.c:2131
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
INFO: task kworker/u8:42:6409 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:42 state:D stack:23544 pid:6409 tgid:6409 ppid:2 task_flags:0x4208160 flags:0x00080000
Workqueue: events_unbound toggle_allocation_gate
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
percpu_rwsem_wait+0x1e6/0x510 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0x100/0x150 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
cpus_read_lock+0x14a/0x160 kernel/cpu.c:491
static_key_enable+0x12/0x20 kernel/jump_label.c:222
toggle_allocation_gate mm/kfence/core.c:874 [inline]
toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:866
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
INFO: task syz.3.828:9868 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.3.828 state:D stack:26808 pid:9868 tgid:9856 ppid:5836 task_flags:0x400140 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
__flush_work+0x7d7/0xcc0 kernel/workqueue.c:4277
flush_work kernel/workqueue.c:4298 [inline]
work_on_cpu_key+0x114/0x170 kernel/workqueue.c:6792
cpu_down_maps_locked+0x1b4/0x1e0 kernel/cpu.c:1492
cpu_down kernel/cpu.c:1502 [inline]
target_store+0x3b8/0x460 kernel/cpu.c:2772
dev_attr_store+0x58/0x80 drivers/base/core.c:2437
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
kernfs_fop_write_iter+0x3af/0x570 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f53b478f7c9
RSP: 002b:00007f53b55e1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f53b49e6270 RCX: 00007f53b478f7c9
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f53b4813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f53b49e6308 R14: 00007f53b49e6270 R15: 00007ffdd55af538
</TASK>
INFO: task syz.3.828:9872 blocked for more than 144 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.828 state:D stack:24968 pid:9872 tgid:9872 ppid:9868 task_flags:0x40064c flags:0x00080001
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
mon_text_release+0x4e/0x3d0 drivers/usb/mon/mon_text.c:650
full_proxy_release+0xc0/0x140 fs/debugfs/file.c:427
__fput+0x402/0xb70 fs/file_table.c:468
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x87f/0x2bd0 kernel/exit.c:971
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop kernel/entry/common.c:75 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline]
irqentry_exit+0x38a/0x8c0 kernel/entry/common.c:196
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f53b478f7c9
RSP: 002b:0000000000000004 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007f53b49e6270 RCX: 00007f53b478f7c9
RDX: 9999999999999999 RSI: 0000000000000004 RDI: 0000000000000000
RBP: 00007f53b4813f91 R08: 0000000000000009 R09: 0000000000000000
R10: ffffffff81000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f53b49e6308 R14: 00007f53b49e6270 R15: 00007ffdd55af538
</TASK>
Showing all locks held in the system:
1 lock held by kthreadd/2:
4 locks held by kworker/u8:0/12:
3 locks held by kworker/1:0/24:
#0: ffff88813ff55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc900001e7c90 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff9013b068 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by khungtaskd/32:
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c94a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/50:
3 locks held by kworker/1:2/794:
#0: ffff88813ff56948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc90003437c90 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff9013b068 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x91/0x1190 net/wireless/reg.c:2453
6 locks held by kworker/u8:6/1104:
3 locks held by kworker/u8:7/1137:
2 locks held by kworker/u8:12/3082:
1 lock held by klogd/5189:
3 locks held by udevd/5200:
3 locks held by dhcpcd/5494:
1 lock held by dhcpcd/5495:
2 locks held by crond/5572:
1 lock held by syz-executor/5816:
2 locks held by syz-executor/5836:
3 locks held by kworker/0:5/5920:
#0: ffff88813ff56548 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc90004a0fc90 ((work_completion)(&vb->update_balloon_stats_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff8e269df0 (cpu_hotplug_lock){++++}-{0:0}, at: all_vm_events+0x1a/0x1f0 mm/vmstat.c:135
3 locks held by kworker/0:6/5922:
#0: ffff88813ff55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc90004a5fc90 ((shepherd).work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff8e269df0 (cpu_hotplug_lock){++++}-{0:0}, at: vmstat_shepherd+0x1c/0x240 mm/vmstat.c:2131
4 locks held by kworker/u8:16/5967:
4 locks held by kworker/u8:17/5993:
5 locks held by kworker/1:7/6099:
#0: ffff88813ff55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000b307c90 ((work_completion)(&wfc.work)#2){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff8e269df0 (cpu_hotplug_lock){++++}-{0:0}, at: cpus_write_lock kernel/cpu.c:509 [inline]
#2: ffffffff8e269df0 (cpu_hotplug_lock){++++}-{0:0}, at: _cpu_down+0xe5/0xf40 kernel/cpu.c:1411
#3: ffff88801cfb10f8 (&pinst->lock){+.+.}-{4:4}, at: padata_cpu_dead+0x10e/0x320 kernel/padata.c:793
#4: ffffffff8e3d4bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311
3 locks held by kworker/u8:18/6169:
3 locks held by kworker/u8:23/6174:
3 locks held by kworker/u8:28/6179:
#0: ffff88803074d148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000b537c90 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff9013b068 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff9013b068 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734
2 locks held by kworker/u8:30/6181:
2 locks held by kworker/u8:33/6184:
4 locks held by kworker/u8:34/6185:
3 locks held by kworker/u8:39/6192:
4 locks held by kworker/u8:41/6408:
3 locks held by kworker/u8:42/6409:
#0: ffff88813ff69148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
#1: ffffc9000bf47c90 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
#2: ffffffff8e269df0 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20 kernel/jump_label.c:222
3 locks held by kworker/u8:43/6410:
2 locks held by getty/6450:
#0: ffff88814e0450a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000bff52f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
1 lock held by syz.2.167/6741:
4 locks held by kworker/u8:44/8977:
4 locks held by kworker/u8:45/8979:
2 locks held by kworker/u8:46/8981:
4 locks held by kworker/u8:47/8982:
3 locks held by kworker/u8:48/8983:
3 locks held by kworker/u8:49/8984:
3 locks held by kworker/u8:50/8985:
3 locks held by syz.3.825/9843:
3 locks held by syz.3.828/9856:
2 locks held by syz.3.828/9858:
2 locks held by syz.3.828/9867:
#0: ffffffff8f765348 (mon_lock){+.+.}-{4:4}, at: mon_text_release+0x4e/0x3d0 drivers/usb/mon/mon_text.c:650
#1: ffffffff8e3d4ac0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x48/0x6e0 kernel/rcu/tree.c:3816
6 locks held by syz.3.828/9868:
#0: ffff8880733237b8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1255
#1: ffff88802f8ea420 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:738
#2: ffff88804ef72488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x28f/0x570 fs/kernfs/file.c:343
#3: ffff888141692698 (kn->active#175){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#3: ffff888141692698 (kn->active#175){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2ff/0x570 fs/kernfs/file.c:344
#4: ffffffff8f2b0088 (device_hotplug_lock){+.+.}-{4:4}, at: lock_device_hotplug_sysfs+0x18/0x70 drivers/base/core.c:2355
#5: ffffffff8e269ea8 (cpu_add_remove_lock){+.+.}-{4:4}, at: cpu_maps_update_begin kernel/cpu.c:469 [inline]
#5: ffffffff8e269ea8 (cpu_add_remove_lock){+.+.}-{4:4}, at: cpu_down kernel/cpu.c:1501 [inline]
#5: ffffffff8e269ea8 (cpu_add_remove_lock){+.+.}-{4:4}, at: target_store+0x3ae/0x460 kernel/cpu.c:2772
6 locks held by syz.1.831/9870:
2 locks held by syz.1.831/9871:
#0: ffffffff90124890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x333/0x7c0 net/core/net_namespace.c:577
#1: ffffffff8e269df0 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190
1 lock held by syz.3.828/9872:
#0: ffffffff8f765348 (mon_lock){+.+.}-{4:4}, at: mon_text_release+0x4e/0x3d0 drivers/usb/mon/mon_text.c:650
2 locks held by syz.4.832/9877:
2 locks held by syz-executor/9876:
2 locks held by kworker/1:11/9878:
=============================================
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 10/25/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x133/0x180 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xe66/0x1180 kernel/hung_task.c:515
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>