INFO: task poweroff:8967 blocked for more than 204 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:poweroff state:D stack:23328 pid:8967 tgid:8967 ppid:5175 task_flags:0x400000 flags:0x00080800
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5310 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
sync_bdevs+0x27e/0x470 block/bdev.c:1304
ksys_sync fs/sync.c:105 [inline]
__ia32_sys_sync+0xc5/0x120 fs/sync.c:111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f51f5de6f37
RSP: 002b:00007ffd6f7f81d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f51f5de6f37
RDX: ffffffffffffff88 RSI: 00007f51f5f7fe51 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd6f7f8338 R14: 00007f51f5fc9000 R15: 000055b8962c3d98
Showing all locks held in the system:
8 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e960320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:2/36:
#0: ffff888031503148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90000ac7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4199
3 locks held by kworker/u8:6/1113:
#0: ffff88813fe04148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90003cbfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
2 locks held by getty/5576:
#0: ffff88803232d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5831:
#0: ffff888026bdb358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
3 locks held by kworker/0:3/5864:
#0: ffff88813ff47548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254
#1: ffffc90004cffc40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255
#2: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by udevd/5996:
#0: ffff888026c9b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by poweroff/8967:
#0: ffff888026bdb358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304
3 locks held by kworker/u8:7/12013:
#0: ffff8880b853ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647
#1: ffff8880b8524588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff8880b8526118 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline]
#2: ffff8880b8526118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085
1 lock held by syz-executor/13000:
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5032
1 lock held by syz-executor/13103:
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
1 lock held by syz.3.1924/13193:
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x83c/0x1150 net/core/dev_ioctl.c:840
1 lock held by syz.3.1924/13196:
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x83c/0x1150 net/core/dev_ioctl.c:840
2 locks held by syz.6.1925/13176:
#0: ffff88805f9fc708 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#0: ffff88805f9fc708 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release+0x89/0x250 net/socket.c:665
#1: ffffffff8fde84c8 (rtnl_mutex){+.+.}-{4:4}, at: raw_release+0x1bc/0xa20 net/can/raw.c:419
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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:161 [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:347 [inline]
watchdog+0x103d/0x1090 kernel/hung_task.c:516
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: netns cleanup_net
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4878 [inline]
RIP: 0010:__lock_acquire+0x50b/0x2cf0 kernel/locking/lockdep.c:5187
Code: 49 8d 1c c6 48 81 c3 38 0b 00 00 eb 1d 44 89 e0 49 ff c7 49 63 8e 10 0b 00 00 48 83 c3 28 41 89 c4 49 39 cf 0f 8d c7 00 00 00 <49> 83 ff 31 0f 83 83 00 00 00 8b 03 25 ff 1f 00 00 48 0f a3 05 bc
RSP: 0018:ffffc90000117248 EFLAGS: 00000093
RAX: 0000000000000004 RBX: ffff88801dab8bb0 RCX: 0000000000000005
RDX: 0000000000000004 RSI: 0000000000000005 RDI: 0000000000000000
RBP: ffff88801dab8be0 R08: ffffffff826eb0cc R09: ffffffff8e960320
R10: dffffc0000000000 R11: ffffed100c9f1079 R12: 0000000000000004
R13: ffff88801dab8be0 R14: ffff88801dab8000 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff888125115000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffacc5a008 CR3: 000000000e74c000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
kernfs_root+0x38/0x230 fs/kernfs/kernfs-internal.h:75
kernfs_root_is_locked fs/kernfs/kernfs-internal.h:109 [inline]
kernfs_parent+0x51/0x190 fs/kernfs/kernfs-internal.h:133
__kernfs_remove+0x9b/0x660 fs/kernfs/dir.c:1488
kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files fs/sysfs/group.c:28 [inline]
sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328
sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352
device_remove_groups drivers/base/core.c:2843 [inline]
device_remove_attrs+0x229/0x280 drivers/base/core.c:2979
device_del+0x51f/0x8f0 drivers/base/core.c:3877
unregister_netdevice_many_notify+0x1e0e/0x2380 net/core/dev.c:12452
unregister_netdevice_many net/core/dev.c:12480 [inline]
default_device_exit_batch+0x981/0xa00 net/core/dev.c:13072
ops_exit_list net/core/net_namespace.c:205 [inline]
ops_undo_list+0x52b/0x940 net/core/net_namespace.c:252
cleanup_net+0x4df/0x7b0 net/core/net_namespace.c:696
process_one_work+0x949/0x1650 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0xb46/0x1140 kernel/workqueue.c:3443
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: 49 8d 1c c6 lea (%r14,%rax,8),%rbx
4: 48 81 c3 38 0b 00 00 add $0xb38,%rbx
b: eb 1d jmp 0x2a
d: 44 89 e0 mov %r12d,%eax
10: 49 ff c7 inc %r15
13: 49 63 8e 10 0b 00 00 movslq 0xb10(%r14),%rcx
1a: 48 83 c3 28 add $0x28,%rbx
1e: 41 89 c4 mov %eax,%r12d
21: 49 39 cf cmp %rcx,%r15
24: 0f 8d c7 00 00 00 jge 0xf1
* 2a: 49 83 ff 31 cmp $0x31,%r15 <-- trapping instruction
2e: 0f 83 83 00 00 00 jae 0xb7
34: 8b 03 mov (%rbx),%eax
36: 25 ff 1f 00 00 and $0x1fff,%eax
3b: 48 rex.W
3c: 0f .byte 0xf
3d: a3 .byte 0xa3
3e: 05 .byte 0x5
3f: bc .byte 0xbc