INFO: task kworker/u8:15:9493 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:15   state:D stack:21128 pid:9493  tgid:9493  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 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:199 [inline]
 ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252
 cleanup_net+0x4d8/0x820 net/core/net_namespace.c:695
 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+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by ksoftirqd/1/23:
 #0: ffff8880b883a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646
1 lock held by khungtaskd/31:
 #0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5589:
 #0: ffff88814ce290a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036ae2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/u8:15/9493:
 #0: ffff88801aed7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88801aed7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc9000b22fba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc9000b22fba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffffffff8f2be8f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 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+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5814 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:kasan_byte_accessible+0x16/0x30 mm/kasan/generic.c:212
Code: 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df 0f b6 04 07 <3c> 08 0f 92 c0 e9 2b 8c ea fe cc 66 66 66 66 66 66 2e 0f 1f 84 00
RSP: 0018:ffffc90003e7f840 EFLAGS: 00000016
RAX: 0000000000000000 RBX: ffffffff819b7abb RCX: a38284148b975f00
RDX: 0000000000000000 RSI: ffffffff819b7abb RDI: 1ffff11017124809
RBP: ffffffff819b8de3 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10060e0001 R12: 0000000000000000
R13: ffff8880b8924048 R14: ffff8880b8924048 R15: 0000000000000001
FS:  0000555561b4c500(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000000 CR3: 000000007723f000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __kasan_check_byte+0x12/0x40 mm/kasan/common.c:579
 kasan_check_byte include/linux/kasan.h:401 [inline]
 lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842
 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline]
 do_write_seqcount_begin include/linux/seqlock.h:503 [inline]
 psi_write_begin+0xab/0x160 kernel/sched/psi.c:183
 psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
 psi_sched_switch kernel/sched/stats.h:220 [inline]
 __schedule+0x22e9/0x4cc0 kernel/sched/core.c:6923
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 do_nanosleep+0x1c5/0x610 kernel/time/hrtimer.c:2116
 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2163
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1398 [inline]
 __se_sys_clock_nanosleep+0x339/0x390 kernel/time/posix-timers.c:1375
 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: 0033:0x7fb6f15c1f43
Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d 1e 66 1f 00 00 74 14 b8 e6 00 00 00 0f 05 <f7> d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10
RSP: 002b:00007fff1d6d04a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb6f15c1f43
RDX: 00007fff1d6d04c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 7fffffffffffffff R09: 3fffffffffffffff
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1d6d0910
R13: 0000000000000004 R14: 00007fff1d6d04fc R15: 00007fff1d6d0590
 </TASK>
vkms_vblank_simulate: vblank timer overrun