INFO: task kworker/u8:9:1161 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9 state:D stack:21216 pid:1161 tgid:1161 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
afs_cell_purge+0x3f1/0x540 fs/afs/cell.c:921
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+0x4de/0x7b0 net/core/net_namespace.c:696
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Showing all locks held in the system:
3 locks held by rcuc/1/28:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:9/1161:
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90004cf7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90004cf7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8e898720 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:670
2 locks held by getty/5556:
#0: ffff8881443b60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/15771:
#0: ffff888041104f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]
#0: ffff888041104f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715
#1: ffff8880411040b0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5314
12 locks held by syz-executor/17232:
4 locks held by syz.7.431/17732:
2 locks held by syz.6.429/17738:
4 locks held by syz.1.428/17737:
2 locks held by syz-executor/17739:
#0: ffffffff8e898720 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1146
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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:160 [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:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17232 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline]
RIP: 0010:__lock_acquire+0x197c/0x2cf0 kernel/locking/lockdep.c:5237
Code: 13 25 ff 0f 00 00 39 05 3e 1d 1e 11 73 06 89 05 36 1d 1e 11 48 8b 02 48 89 df 4c 39 e8 0f 84 2c fe ff ff 4c 89 60 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 18 fe ff ff 48 89 fb 48 c7 c7 f0 e0 47
RSP: 0018:ffffc90005be6600 EFLAGS: 00000006
RAX: ffffffff95720438 RBX: 0000000000000101 RCX: 0000000000000002
RDX: ffffffff953e6748 RSI: ffff88804d5b6858 RDI: 0000000000000101
RBP: 5fadd42b3240393b R08: ffffc90005be65c8 R09: 0000000000000020
R10: dffffc0000000000 R11: ffffffff819cebf0 R12: ffffc90005be6690
R13: ffffffff925c0820 R14: ffff88804d5b5ac0 R15: 0000000000000001
FS: 0000555569b3d500(0000) GS:ffff888126def000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c316071 CR3: 0000000059ea8000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
lock_hrtimer_base kernel/time/hrtimer.c:164 [inline]
hrtimer_try_to_cancel+0x22b/0x420 kernel/time/hrtimer.c:1355
update_curr_dl_se+0x2f8/0xb70 kernel/sched/deadline.c:1487
update_curr+0x226/0x500 kernel/sched/fair.c:1227
dequeue_entity kernel/sched/fair.c:5353 [inline]
dequeue_entities+0x1b8/0x2e30 kernel/sched/fair.c:7026
dequeue_task_fair+0x205/0x770 kernel/sched/fair.c:7125
sched_change_begin+0x3ca/0x680 kernel/sched/core.c:10798
class_sched_change_constructor kernel/sched/sched.h:3979 [inline]
do_set_cpus_allowed+0x23/0x90 kernel/sched/core.c:2671
migrate_disable_switch kernel/sched/core.c:2351 [inline]
__schedule+0x166d/0x5070 kernel/sched/core.c:6749
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5945
Code: 18 00 00 b8 ff ff ff ff 65 0f c1 05 83 c2 e1 06 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 4a bb 03 00 cc 90 0f 0b 90 48 c7
RSP: 0018:ffffc90005be6e80 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000046
RDX: 00000000ea98fdfb RSI: ffffffff8cfdeed8 RDI: ffffffff8b3f57e0
RBP: 00000000ffffffff R08: ffffffff8ad3e001 R09: ffffffff8d5ae940
R10: dffffc0000000000 R11: fffffbfff1db668f R12: 0000000000000246
R13: ffff88804d5b5ac0 R14: ffff8880b8946458 R15: 0000000000000009
lock_is_held include/linux/lockdep.h:249 [inline]
___slab_alloc+0x82c/0x13e0 mm/slub.c:4545
__slab_alloc+0xc6/0x1f0 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5251 [inline]
kmem_cache_alloc_node_noprof+0x1b6/0x6f0 mm/slub.c:5315
__alloc_skb+0x1dc/0x3a0 net/core/skbuff.c:679
alloc_skb include/linux/skbuff.h:1383 [inline]
nlmsg_new include/net/netlink.h:1055 [inline]
inet6_ifmcaddr_notify+0xeb/0x1d0 net/ipv6/mcast.c:909
__ipv6_dev_mc_inc+0x8a9/0xa50 net/ipv6/mcast.c:973
ipv6_add_dev+0xe72/0x1400 net/ipv6/addrconf.c:472
addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3650
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2268 [inline]
call_netdevice_notifiers net/core/dev.c:2282 [inline]
register_netdevice+0x15d2/0x1a80 net/core/dev.c:11431
nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1061 [inline]
nsim_create+0xb51/0x1060 drivers/net/netdevsim/netdev.c:1143
__nsim_dev_port_add+0x6a6/0xaf0 drivers/net/netdevsim/dev.c:1493
nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1549
nsim_drv_probe+0x8ad/0xbd0 drivers/net/netdevsim/dev.c:1709
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x26d/0xad0 drivers/base/dd.c:659
__driver_probe_device+0x18c/0x320 drivers/base/dd.c:801
driver_probe_device+0x4f/0x240 drivers/base/dd.c:831
__device_attach_driver+0x279/0x430 drivers/base/dd.c:959
bus_for_each_drv+0x254/0x2e0 drivers/base/bus.c:500
__device_attach+0x2bb/0x430 drivers/base/dd.c:1031
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1086
bus_probe_device+0x12d/0x220 drivers/base/bus.c:574
device_add+0x7b6/0xb80 drivers/base/core.c:3689
nsim_bus_dev_new drivers/net/netdevsim/bus.c:463 [inline]
new_device_store+0x36c/0x6f0 drivers/net/netdevsim/bus.c:191
kernfs_fop_write_iter+0x3b0/0x540 fs/kernfs/file.c:352
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5d5/0xb40 fs/read_write.c:686
ksys_write+0x14b/0x260 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5e57c5e1ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fff64f88480 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f5e57c5e1ff
RDX: 0000000000000003 RSI: 00007fff64f884d0 RDI: 0000000000000005
RBP: 00007f5e57ce52ef R08: 0000000000000000 R09: 00007fff64f882d7
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 00007fff64f884d0 R14: 00007f5e589e4620 R15: 0000000000000003