INFO: task kworker/u8:10:4565 blocked for more than 144 seconds.
Not tainted 6.16.0-rc3-next-20250626-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:10 state:D stack:19448 pid:4565 tgid:4565 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5313 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6696
__schedule_loop kernel/sched/core.c:6774 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6789
afs_cell_purge+0x3d9/0x540 fs/afs/cell.c:893
afs_net_exit+0x50/0x100 fs/afs/main.c:147
ops_exit_list net/core/net_namespace.c:200 [inline]
ops_undo_list+0x49a/0x990 net/core/net_namespace.c:253
cleanup_net+0x4c5/0x800 net/core/net_namespace.c:686
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e33bf20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e33bf20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e33bf20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
3 locks held by kworker/u8:10/4565:
#0: ffff88801b6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801b6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc9000eacfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc9000eacfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffffffff8f71da50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662
1 lock held by syslogd/5187:
#0: ffff8880b8639f58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
2 locks held by getty/5591:
#0: ffff8880303c10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
7 locks held by kworker/0:3/5867:
#0: ffff88801e297148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801e297148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc900042f7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc900042f7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffff888028575198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#2: ffff888028575198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5897
#3: ffff88807c696198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#3: ffff88807c696198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x950 drivers/usb/core/hub.c:2338
#4: ffff88805e428160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#4: ffff88805e428160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline]
#4: ffff88805e428160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292
#5: ffffffff8f1ac4c8 (input_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:225 [inline]
#5: ffffffff8f1ac4c8 (input_mutex){+.+.}-{4:4}, at: __input_unregister_device+0x2d8/0x5e0 drivers/input/input.c:2221
#6: ffffffff8e341a38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#6: ffffffff8e341a38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:967
5 locks held by kworker/0:6/13983:
#0: ffff88801e297148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#0: ffff88801e297148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3322
#1: ffffc9000bac7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3215 [inline]
#1: ffffc9000bac7bc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3322
#2: ffff8880284a5198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#2: ffff8880284a5198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5897
#3: ffff88807c697198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#3: ffff88807c697198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1004
#4: ffff88807c695160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#4: ffff88807c695160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1004
4 locks held by udevd/21955:
#0: ffff88805ff77540 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182
#1: ffff888028dc4488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154
#2: ffff8880665e2e18 (kn->active#24){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155
#3: ffff88807c697198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:889 [inline]
#3: ffff88807c697198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
2 locks held by syz.0.5953/24316:
#0: ffffffff8f72a708 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
#0: ffffffff8f72a708 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396
#1: ffffffff8e341a38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e341a38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:967
1 lock held by syz.4.5963/24338:
#0: ffffffff8e341900 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3792
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-next-20250626-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:470
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 5867 Comm: kworker/0:3 Not tainted 6.16.0-rc3-next-20250626-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:kvm_sched_clock_read+0xc/0x20 arch/x86/kernel/kvmclock.c:91
Code: 00 65 c6 05 6f 9f 4d 07 00 eb 9a cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 3d 24 da 4d 07 4f 00 00 00 48 2b 05 a0 80 52 02 c3 cc cc cc cc cc cc cc 90 90
RSP: 0018:ffffc90000007e20 EFLAGS: 00000082
RAX: ffffffff8167b56b RBX: ffff8880b8623e58 RCX: ffff88802f66da00
RDX: 0000000000010000 RSI: ffffffff8be4abe0 RDI: ffffffff92c9d000
RBP: ffffc90000007f18 R08: ffffffff8fc2b637 R09: 1ffffffff1f856c6
R10: dffffc0000000000 R11: fffffbfff1f856c7 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffc90000007ea0 R15: 1ffff92000000fd0
FS: 0000000000000000(0000) GS:ffff8881259e6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8097b7e2d8 CR3: 000000006d990000 CR4: 00000000003526f0
Call Trace:
sched_clock+0x17/0x60 arch/x86/kernel/tsc.c:288
sched_clock_cpu+0x74/0x430 kernel/sched/clock.c:397
irqtime_account_irq+0x6e/0x1c0 kernel/sched/cputime.c:67
account_hardirq_exit include/linux/vtime.h:154 [inline]
__irq_exit_rcu+0x8d/0x1f0 kernel/softirq.c:677
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449
Code: 85 32 01 00 00 e8 11 59 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 00 59 1f 00 eb 06 e8 f9 58 1f 00 fb 48 c7 c7 c0 01 33 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 a9 36
RSP: 0018:ffffc900042f7120 EFLAGS: 00000283
RAX: ffffffff81a0b387 RBX: ffffffff81a0b244 RCX: 0000000000100000
RDX: ffffc900169b0000 RSI: 000000000001796f RDI: ffffffff8e3301c0
RBP: ffffc900042f7230 R08: ffffffff8fc2b637 R09: 1ffffffff1f856c6
R10: dffffc0000000000 R11: fffffbfff1f856c7 R12: dffffc0000000000
R13: 1ffff9200085ee28 R14: 0000000000000200 R15: 0000000000000046
_printk+0xcf/0x120 kernel/printk/printk.c:2475
dvb_usb_device_exit+0x29b/0x350 drivers/media/usb/dvb-usb/dvb-usb-init.c:342
usb_unbind_interface+0x26b/0x910 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:569 [inline]
__device_release_driver drivers/base/dd.c:1272 [inline]
device_release_driver_internal+0x4d6/0x7c0 drivers/base/dd.c:1295
bus_remove_device+0x34d/0x410 drivers/base/bus.c:579
device_del+0x511/0x8e0 drivers/base/core.c:3880
usb_disable_device+0x3e9/0x8a0 drivers/usb/core/message.c:1418
usb_disconnect+0x330/0x950 drivers/usb/core/hub.c:2347
hub_port_connect drivers/usb/core/hub.c:5409 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5709 [inline]
port_event drivers/usb/core/hub.c:5869 [inline]
hub_event+0x1cdb/0x4a00 drivers/usb/core/hub.c:5951
process_one_work kernel/workqueue.c:3239 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3322
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3403
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245