INFO: task kworker/u8:4:14014 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/u8:4 state:D stack:22296 pid:14014 tgid:14014 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x1681/0x54c0 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7282
rxrpc_destroy_all_calls+0x44e/0x570 net/rxrpc/call_object.c:752
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:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
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/37:
#0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc80c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
6 locks held by kworker/u8:14/2365:
2 locks held by kworker/1:2/3139:
1 lock held by udevd/5184:
2 locks held by getty/5568:
#0: ffff8880329f40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
5 locks held by syz-executor/5815:
2 locks held by syz-executor/5816:
5 locks held by kworker/u8:2/14006:
3 locks held by kworker/u8:4/14014:
#0: ffff88801b2a8938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff88801b2a8938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc9000686fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc9000686fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffffffff8f35d120 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
5 locks held by kworker/u8:8/14019:
2 locks held by kworker/1:1/24307:
4 locks held by kworker/u8:20/31642:
2 locks held by syz.1.13983/4152:
3 locks held by syz.1.13983/4157:
4 locks held by syz.6.13985/4154:
5 locks held by syz.5.13987/4165:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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: 4165 Comm: syz.5.13987 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:arch_static_branch include/trace/events/preemptirq.h:40 [inline]
RIP: 0010:trace_irq_enable+0x0/0x140 include/trace/events/preemptirq.h:40
Code: 00 00 65 c7 05 ed a5 a6 10 00 00 00 00 c3 cc cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 57 41 56 41 54 53 66 90 65 8b 05 d4 8c a5 10 83 f8 08 73 37 89
RSP: 0018:ffffc900066bf578 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000246 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8b305c20
RBP: ffffc900066bf6a0 R08: ffff888037a7a243 R09: 1ffff11006f4f448
R10: dffffc0000000000 R11: ffffed1006f4f449 R12: dffffc0000000000
R13: 1ffff92000cd7ebc R14: ffff888037a7a240 R15: ffff888037a7a240
FS: 00007f01896fd6c0(0000) GS:ffff8881260fb000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000001e2030 CR3: 000000007187c000 CR4: 00000000003526f0
Call Trace:
trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:73
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline]
_raw_spin_unlock_irqrestore+0x30/0x80 kernel/locking/spinlock.c:198
unlock_rt_mutex_safe kernel/locking/rtmutex.c:350 [inline]
rt_mutex_slowunlock+0x4a7/0x8b0 kernel/locking/rtmutex.c:1463
spin_unlock_irqrestore include/linux/spinlock_rt.h:129 [inline]
__skb_try_recv_datagram+0xa9/0x1b0 net/core/datagram.c:267
__unix_dgram_recvmsg+0x2e3/0xd60 net/unix/af_unix.c:2577
sock_recvmsg_nosec+0x10c/0x140 net/socket.c:1137
____sys_recvmsg+0x3ef/0x4b0 net/socket.c:2916
___sys_recvmsg+0x215/0x590 net/socket.c:2960
do_recvmmsg+0x33a/0x800 net/socket.c:3055
__sys_recvmmsg net/socket.c:3129 [inline]
__do_sys_recvmmsg net/socket.c:3152 [inline]
__se_sys_recvmmsg net/socket.c:3145 [inline]
__x64_sys_recvmmsg+0x198/0x250 net/socket.c:3145
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f018b4cc819
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:00007f01896fd028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f018b746090 RCX: 00007f018b4cc819
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f018b562c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f018b746128 R14: 00007f018b746090 R15: 00007ffef9895fa8