INFO: task kworker/u8:7:1338 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7 state:D stack:21480 pid:1338 tgid:1338 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5360 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7046 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7061
afs_cell_purge+0x3d9/0x540 fs/afs/cell.c:894
afs_net_exit+0x50/0x100 fs/afs/main.c:147
ops_exit_list net/core/net_namespace.c:198 [inline]
ops_undo_list+0x49a/0x990 net/core/net_namespace.c:251
cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
9 locks held by kworker/0:0/9:
#0: ffff888020edc948 (
(wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
(wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc900000e7ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc900000e7ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff888027e63198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888027e63198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
#3: ffff888078082198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff888078082198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#4: ffff888144ebf278 (&(&priv->bus_notifier)->rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379
#5:
ffff8880b8639f98
(&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
#6:
ffff8880b8624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#7: ffff8880b8624008 (psi_seq){-.-.}-{0:0}, at: psi_task_change+0xd9/0x340 kernel/sched/psi.c:919
#8: ffff88802f3a8a68 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
#8: ffff88802f3a8a68 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0x67/0x12b0 kernel/sched/core.c:4216
2 locks held by kworker/u8:0/12:
#0: ffff8880b8739f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
#1: ffff8880b8724008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
1 lock held by khungtaskd/31:
#0: ffffffff8e53c560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53c560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53c560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:7/1338:
#0: ffff88801b6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88801b6fe948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000462fba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000462fba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8f945770 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:658
2 locks held by getty/5624:
#0: ffff88814da2f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:1/11118:
#0: ffff888020edc948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888020edc948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90004847ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90004847ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff888145f94198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888145f94198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 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: 5851 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:sock_read_iter+0x196/0x2f0 net/socket.c:1148
Code: 0f b6 04 18 84 c0 0f 85 4d 01 00 00 45 8b 6d 00 44 89 ee 83 e6 08 31 ff e8 47 67 59 f8 41 83 e5 08 75 0e e8 fc 62 59 f8 eb 17 f5 62 59 f8 eb 05 e8 ee 62 59 f8 c7 84 24 84 00 00 00 40 00 00
RSP: 0018:ffffc900040afb60 EFLAGS: 00000206
RAX: ffffffff89669a07 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff888029848000 RSI: 0000000000000800 RDI: 0000000000000000
RBP: ffffc900040afc90 R08: ffffc900040afc07 R09: 0000000000000000
R10: ffffc900040afbf8 R11: fffff52000815f81 R12: ffffc900040afd20
R13: 0000000000000800 R14: ffffc900040afba0 R15: 1ffff92000815f70
FS: 000055556483a500(0000) GS:ffff8881257b1000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f997a934391 CR3: 0000000074eae000 CR4: 00000000003526f0
Call Trace:
new_sync_read fs/read_write.c:491 [inline]
vfs_read+0x557/0xa30 fs/read_write.c:572
ksys_read+0x145/0x250 fs/read_write.c:715
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff26738d57d
Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b5 e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d e1 af 21 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
RSP: 002b:00007ffc351f5f68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff26738d57d
RDX: 0000000000000004 RSI: 00007ffc351f5f7c RDI: 0000000000000003
RBP: 0000000000000000 R08: 000000000434abbe R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc351f6390
R13: 0000000000000004 R14: 00007ffc351f5f7c R15: 00007ffc351f6010