INFO: task kworker/u8:18:6639 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/u8:18 state:D stack:20336 pid:6639 tgid:6639 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
afs_cell_purge+0x40d/0x580 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+0x49f/0x940 net/core/net_namespace.c:252
cleanup_net+0x56b/0x800 net/core/net_namespace.c:704
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
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
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
1 lock held by khungtaskd/31:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5570:
#0: ffff888036d790a0 (&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
3 locks held by kworker/1:4/5829:
3 locks held by kworker/u8:18/6639:
#0: ffff88801b6ce948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801b6ce948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90003277c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90003277c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffffffff8fbbde70 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
2 locks held by kworker/u8:26/8205:
#0: ffff88801b7e7948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88801b7e7948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90005267c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90005267c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
4 locks held by kworker/0:7/12825:
#0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655
#1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffffffff8e923298 (kernfs_notify_lock){....}-{3:3}, at: spin_lock_irq include/linux/spinlock.h:371 [inline]
#2: ffffffff8e923298 (kernfs_notify_lock){....}-{3:3}, at: kernfs_notify_workfn+0x5a5/0x620 fs/kernfs/file.c:919
#3: ffff88801b6cd988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_notify_workfn+0x104/0x620 fs/kernfs/file.c:933
1 lock held by syz-executor/20888:
#0: ffff8880771240e0 (&type->s_umount_key#96){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880771240e0 (&type->s_umount_key#96){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880771240e0 (&type->s_umount_key#96){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
2 locks held by syz.7.3992/23806:
2 locks held by dhcpcd/23808:
#0: ffff888082f18208 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#0: ffff888082f18208 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff888082f18208 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
#1: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by rm/23822:
=============================================
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 02/12/2026
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:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
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: 8205 Comm: kworker/u8:26 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:preempt_latency_start kernel/sched/core.c:5746 [inline]
RIP: 0010:preempt_count_add+0xad/0x190 kernel/sched/core.c:5769
Code: 42 48 8b 5c 24 18 48 89 df e8 2f 21 0e 00 85 c0 74 09 31 db 31 ff e8 22 21 0e 00 65 4c 8b 35 a2 d9 87 11 49 81 c6 08 15 00 00 <4c> 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 6d cb 9b 00
RSP: 0018:ffffc900052675f8 EFLAGS: 00000086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff9a272400
RDX: 0000000000000000 RSI: ffffffff8c27a9e0 RDI: 0000000000000000
RBP: 0000000000a12008 R08: ffffffff901181b7 R09: 1ffffffff2023036
R10: dffffc0000000000 R11: fffffbfff2023037 R12: ffff88802530f400
R13: ffff88802530f000 R14: ffff888026713348 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125564000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e622128138 CR3: 00000000758e6000 CR4: 0000000000350ef0
Call Trace:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:131 [inline]
_raw_spin_lock_irqsave+0x24/0x60 kernel/locking/spinlock.c:162
__debug_check_no_obj_freed lib/debugobjects.c:1088 [inline]
debug_check_no_obj_freed+0x145/0x550 lib/debugobjects.c:1129
slab_free_hook mm/slub.c:2618 [inline]
slab_free mm/slub.c:6124 [inline]
kfree+0x13a/0x630 mm/slub.c:6442
ieee80211_ibss_rx_queued_mgmt+0x1acf/0x2cd0 net/mac80211/ibss.c:-1
ieee80211_iface_process_skb net/mac80211/iface.c:1748 [inline]
ieee80211_iface_work+0x84e/0x1340 net/mac80211/iface.c:1802
cfg80211_wiphy_work+0x2ab/0x4a0 net/wireless/core.c:440
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
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