INFO: task kworker/u8:15:11017 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/u8:15 state:D stack:23480 pid:11017 tgid:11017 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
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
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by udevd/4968:
#0: ffff88803745a480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
2 locks held by getty/5359:
#0: ffff8880372db0a0 (&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
4 locks held by syz-executor/5604:
2 locks held by syz-executor/5605:
8 locks held by kworker/0:2H/9771:
3 locks held by kworker/u8:15/11017:
#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: ffffc90005d97c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90005d97c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8f340fa0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
1 lock held by syz-executor/12347:
5 locks held by kworker/0:2/12644:
3 locks held by syz.6.2508/13013:
1 lock held by syz.6.2508/13014:
#0: ffff888031ba3490 (&substream->lock){+.+.}-{3:3}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:660
2 locks held by syz.6.2508/13019:
3 locks held by syz.7.2509/13018:
=============================================
NMI backtrace for cpu 1
CPU: 1 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:
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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13014 Comm: syz.6.2508 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:preempt_count_add+0x6d/0x190 kernel/sched/core.c:5859
Code: c7 c0 e0 23 75 99 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e5 00 00 00 83 3d bf a7 e1 17 00 75 11 65 8b 05 06 54 d6 10 0f b6 c0 <3d> f5 00 00 00 73 5d 65 8b 05 f5 53 d6 10 25 ff ff ff 7f 39 f8 75
RSP: 0018:ffffc9000405f6d0 EFLAGS: 00000046
RAX: 0000000000000002 RBX: ffff88802dd16718 RCX: ffffffff99752303
RDX: 0000000000000000 RSI: 0000000000000011 RDI: 0000000000000001
RBP: ffffc9000405f950 R08: ffffc9000405f8cf R09: 0000000000000000
R10: ffffc9000405f860 R11: fffff5200080bf1a R12: dffffc0000000000
R13: ffffc9000405f888 R14: ffff88802dd15c40 R15: dffffc0000000000
FS: 00007f256738e6c0(0000) GS:ffff888126183000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 0000000040ea0000 CR4: 00000000003526f0
DR0: 0000000000000001 DR1: 00000000000001f8 DR2: 0000000000000003
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__raw_spin_lock include/linux/spinlock_api_smp.h:157 [inline]
_raw_spin_lock+0x12/0x40 kernel/locking/spinlock.c:158
rtlock_slowlock_locked+0x1ec/0x3c80 kernel/locking/rtmutex.c:1866
rtlock_slowlock kernel/locking/rtmutex.c:1914 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x165/0x400 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:45 [inline]
remove_wait_queue+0x23/0x110 kernel/sched/wait.c:73
snd_rawmidi_write+0x3ef/0xc10 sound/core/rawmidi.c:1617
do_loop_readv_writev fs/read_write.c:852 [inline]
vfs_writev+0x4c6/0x9a0 fs/read_write.c:1061
do_writev+0x15a/0x2e0 fs/read_write.c:1105
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f256913ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f256738e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f25693b5fa0 RCX: 00007f256913ce59
RDX: 0000000000000002 RSI: 0000200000000840 RDI: 0000000000000008
RBP: 00007f25691d2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f25693b6038 R14: 00007f25693b5fa0 R15: 00007fffda2942a8