INFO: task kworker/u8:2:15120 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:2    state:D stack:23520 pid:15120 tgid:15120 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x16ec/0x5620 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 rxrpc_destroy_all_calls+0x44e/0x570 net/rxrpc/call_object.c:754
 rxrpc_exit_net+0x6f/0xc0 net/rxrpc/net_ns.c:112
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252
 cleanup_net+0x56e/0x800 net/core/net_namespace.c:702
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 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:
4 locks held by ktimers/1/29:
1 lock held by khungtaskd/38:
 #0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:1H/98:
 #0: ffff88801a037538 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801a037538 ((wq_completion)events_highpri){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90002f3fc40 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90002f3fc40 ((work_completion)(&vmidi->output_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff888031fc4490 (&substream->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #2: ffff888031fc4490 (&substream->lock){+.+.}-{3:3}, at: class_spinlock_irqsave_constructor include/linux/spinlock.h:619 [inline]
 #2: ffff888031fc4490 (&substream->lock){+.+.}-{3:3}, at: snd_rawmidi_transmit+0x25/0xe0 sound/core/rawmidi.c:1486
5 locks held by kworker/u8:8/191:
2 locks held by udevd/4971:
2 locks held by getty/5361:
 #0: ffff8880369cb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
7 locks held by kworker/u8:25/8595:
3 locks held by kworker/u8:2/15120:
 #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc9000ce27c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc9000ce27c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8f3407e0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
6 locks held by kworker/u8:5/15821:
7 locks held by kworker/u8:24/18476:
2 locks held by dhcpcd-run-hook/18661:
 #0: ffff888035e9b7b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline]
 #0: ffff888035e9b7b0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2c2/0x9e0 mm/mmap.c:1308
 #1: ffff8880263f3678 (&mapping->i_mmap_rwsem){++++}-{4:4}, at: i_mmap_lock_write include/linux/fs.h:513 [inline]
 #1: ffff8880263f3678 (&mapping->i_mmap_rwsem){++++}-{4:4}, at: unlink_file_vma_batch_process+0x9f/0x350 mm/vma.c:1800
2 locks held by syz.8.3029/18677:
1 lock held by syz.8.3029/18691:
7 locks held by syz.3.3035/18694:
1 lock held by syz.3.3035/18696:
4 locks held by syz.3.3035/18698:
1 lock held by syz.6.3036/18704:
2 locks held by syz.6.3036/18707:
 #0: ffffffff8e1097f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
 #0: ffffffff8e1097f0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x27/0x60 include/linux/srcu.h:294
 #1: ffff88801b6dea58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #1: ffff88801b6dea58 (&n->list_lock){+.+.}-{3:3}, at: __slab_free+0xf1/0x2a0 mm/slub.c:5559
4 locks held by syz.9.3037/18705:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 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: 29 Comm: ktimers/1 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline]
RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
RIP: 0010:do_raw_spin_lock+0x10f/0x2f0 kernel/locking/spinlock_debug.c:116
Code: 0f 85 af 01 00 00 41 8b 45 00 65 8b 0d ae b2 c8 10 39 c8 0f 84 2b 01 00 00 41 c6 44 14 04 04 c7 44 24 40 00 00 00 00 48 89 df <be> 04 00 00 00 49 89 d6 e8 f4 ab 8a 00 48 8d 7c 24 40 be 04 00 00
RSP: 0018:ffffc90000a3f8a0 EFLAGS: 00000082
RAX: 00000000ffffffff RBX: ffff8880319dc930 RCX: 0000000000000001
RDX: dffffc0000000000 RSI: ffffffff8d85e8b7 RDI: ffff8880319dc930
RBP: ffffc90000a3f958 R08: ffffffff8b1dc7cf R09: ffff8880319dc948
R10: dffffc0000000000 R11: fffffbfff1f10b9f R12: 1ffff92000147f18
R13: ffff8880319dc938 R14: ffff8880319dc940 R15: 1ffff1100633b927
FS:  0000000000000000(0000) GS:ffff888126286000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000032000 CR3: 0000000075b7a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock_irqsave+0x4c/0x60 kernel/locking/spinlock.c:166
 rt_mutex_slowunlock+0xbf/0x8b0 kernel/locking/rtmutex.c:1426
 spin_unlock include/linux/spinlock_rt.h:109 [inline]
 snd_timer_process_callbacks sound/core/timer.c:794 [inline]
 snd_timer_interrupt+0x1046/0x1330 sound/core/timer.c:912
 snd_hrtimer_callback+0x21e/0x390 sound/core/hrtimer.c:51
 __run_hrtimer kernel/time/hrtimer.c:1930 [inline]
 __hrtimer_run_queues+0x405/0xb10 kernel/time/hrtimer.c:1994
 hrtimer_run_softirq+0x18f/0x260 kernel/time/hrtimer.c:2011
 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1151
 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>